JP5651397B2 - Roll mold, roll forming device, processing method - Google Patents

Description

  The present invention relates to a roll forming apparatus for forming a metal plate while rotating it into a desired shape, and in particular, a roll mold capable of forming at a bending radius equal to or less than the thickness (plate thickness) of a high strength steel plate (high tensile material), The present invention relates to a roll forming apparatus to which the roll mold is attached and a processing method.

  Conventionally, a cold roll forming apparatus (hereinafter referred to as a roll forming apparatus) has been widely used for forming a metal plate as a base of various metal products into various desired shapes. A forming line in which a number of cold roll forming machines (hereinafter referred to as roll forming machines) having a forming roll stand (hereinafter referred to as a roll stand) to which a roll mold composed of a lower mold is mounted, and a material supply on the upstream side thereof Ancillary equipment and downstream process equipment such as drilling, cutting and bending are connected downstream.

In this roll forming apparatus or roll forming machine, a metal plate serving as a base for various metal products is formed into various desired shapes by cold.
Since it is a cold forming process for retaining the original material of the metal plate, there may be a problem that a crack occurs in the forming part depending on the material of the metal plate and the shape to be formed. In particular, when the metal plate is a high tensile strength steel plate (high-tensile material), it becomes a big problem.

  In order to solve the problem of cracking that occurs during the cold forming of such a roll forming apparatus or roll forming machine, for example, Patent Document 1 discloses that a width-adjusting roll skewed with respect to the edge of a wide material is placed between required roll stands. By placing the roll surface in contact with the edge, the material can be fed to the center very smoothly, improving the formability of the concavo-convex shape and preventing cracks in the pocket wave and the bent part. A technique of a roll forming machine having a width-shifting roll that can be made is disclosed.

Japanese Patent Laid-Open No. 05-069048

However, in the roll forming machine according to Patent Document 1, the width-adjusting roll skewed with respect to the edge of the metal plate that is the base of the metal product must be disposed between the required roll stands. There is a problem that the molding machine cannot be used as it is. Furthermore, since the width-adjusting roll must be disposed between the required roll stands, there is a problem that the cost of the roll forming apparatus is increased.
In addition, the width-adjusting roll skewed with respect to the edge of the metal plate when changing the roll mold every time the shape of the metal product is changed, or when changing the metal plate whenever the material of the metal product is changed There is also a problem that adjustment of the position, angle, etc. of the lens requires skill and takes time.
And, the method of placing the width-adjusting roll skewed with respect to the edge of the metal plate between the required roll stands and bringing the roll surface into contact with the edge is effective for a soft metal plate having a wide width and having a good elongation. However, there is a problem with high tensile strength steel sheets (high-tensile materials) that cracks occur at the forming location, and in particular, high-tensile strength steel sheets (high-tensile materials) are formed and processed with a radius that is less than the thickness (plate thickness) of the metal plate There is a problem that it is not possible to cope with the cracks that occur.

  The present invention has been made to solve the above-described problems, and includes a first pair of upper molds / lower molds that are molded into a desired shape with a bending radius at least equal to or less than the thickness (plate thickness) of a metal plate. 1 roll mold and a second roll mold composed of an upper mold / lower mold for forming a shape for inserting a metal plate into the first roll mold, the first roll mold and the second roll mold The bending angle for bending the metal plate formed on the metal plate is the same, and the upper die of the first roll type and the upper die of the second roll type are in contact with the inner bending surface of the metal plate. When the bending radius for bending the metal plate formed on the upper die of the second roll mold is set to a predetermined range larger than the thickness (plate thickness) of the metal plate, the conventional roll forming machine has an extra Can be used as-is by simply replacing the roll type without the need for additional equipment. Even after changing the mold, there is no need to adjust the cracks that occur in the metal plate forming part, and even when a high tensile strength steel plate (high-tensile material) is formed and processed with a radius less than the thickness (plate thickness) of the target metal plate. An object of the present invention is to provide a roll forming apparatus and a processing method having a roll mold that does not cause cracks at a location, and a roll forming machine equipped with the roll mold.

In order to achieve the object, the roll mold according to claim 1 is a roll mold that is mounted on a roll forming apparatus and roll-forms a high-strength steel sheet having a thickness T of 1.6 mm or less, and the high-strength steel sheet A first roll mold having a first inner mold for inner bending and a first lower mold for outer bending, and a second upper for inner bending for roll-forming the high strength steel sheet supplied from the first roll mold. A second roll mold having a mold and a second lower mold for outer bending, the first upper mold for inner bending of the first roll mold, the first lower mold for outer bending, and the second roll mold The bending angles for bending the high strength steel plates formed on the roll forming surfaces of the second upper mold for inner bending and the second lower mold for outer bending are formed at the same angle, and the first bending inner first of the first roll mold. The radius c of the inner bending arc C1 formed in the upper mold is 2T ≦ ≦ 4 mm is set to the radius a of the inner bend for arc A1 in the second upper die for the inner bend is set at a ≦ T, the second roll-type the high tensile strength steel sheet which has been fed from the first roll-type Bending caused by pressing of the surface contact portion between the outer bending surface of the high tensile strength steel plate and the outer bending surface of the second lower die and the inner bending arc A1 portion of the second inner bending upper die when roll forming is performed. It is characterized by suppressing the moment

  A roll mold according to claim 2 is the roll mold according to claim 1, wherein the inner bending arc C1 and the outer bending arc formed in the first upper mold for inner bending of the first roll mold. The outer bending surface arc S formed on the opposite side of the inner bending surface arc C2 and the inner bending surface arc C2 of the high strength steel plate formed by the first lower mold is the second upper inner bending surface of the second roll type. When roll forming is performed by the inner bending arc A1 formed in the mold and the outer lower bending second mold, an extension allowance is generated.

  The roll mold according to claim 3 is formed on the outer side of the high-strength steel sheet when the roll mold according to claim 1 or 2 is roll-formed through the second roll mold. A gap D is formed between the outer bending surface arc B and the corner portion of the second lower die for outer bending.

According to a fourth aspect of the present invention, there is provided a roll forming apparatus for roll forming a high strength steel sheet having a thickness T of 1.6 mm or less. A first roll forming machine equipped with a first roll mold having a mold and a first lower mold for outer bending, and a second upper mold for inner bending that roll-forms the high strength steel sheet supplied from the first roll mold And a second roll molding machine equipped with a second roll mold having a second lower mold for outer bending, a first upper mold for inner bending and a first lower mold for outer bending of the first roll mold, The bending angles for bending the high strength steel plates formed on the roll forming surfaces of the second upper die for inner bending and the second lower die for outer bending of the second roll die are formed at the same angle, respectively. Inner bending circle formed on the first upper mold for inner bending of roll type The radius c of C1 is set to 2T ≦ c ≦ 4 mm, the radius a of the inner bend for arc A1 in the second upper-die the inner bend is set to a ≦ T, the high supplied from the first roll-type When roll-forming the tensile strength steel sheet with the second roll mold, the surface contact portion between the outer bending surface of the high strength steel sheet and the outer bending surface of the second lower mold and the inner bending arc in the second upper mold for inner bending. Bending moment generated by pressing the A1 portion is suppressed .

  A roll forming apparatus according to claim 5 is the roll forming apparatus according to claim 4, wherein the roll forming apparatus is formed on the first upper mold for inward bending of the first roll mold mounted on the first roll forming machine. The outer bending surface arc S formed on the opposite side of the inner bending surface arc C2 and the inner bending surface arc C2 of the high strength steel plate formed by the inner bending arc C1 and the outer lower bending first mold, When the roll is formed by the inner bending arc A1 formed on the second upper mold for inner bending of the second roll mold mounted on the second roll molding machine and the second lower mold for outer bending, An extension allowance is generated.

  A roll forming apparatus according to claim 6 is the roll forming apparatus according to claim 4 or 5, wherein the roll forming apparatus is roll-formed through the second roll mold mounted on the second roll forming machine. In addition, a gap D is formed between the outer bending surface arc B formed on the outer side of the high tensile strength steel plate and the corner of the second lower die for outer bending.

  A roll forming apparatus according to a seventh aspect is the roll forming apparatus according to any one of the fourth to sixth aspects, wherein the inner bending arc A1 in the second upper mold for inner bending of the second roll forming machine. The inside bending surface arc A2 of the high strength steel sheet roll-formed so that the radius is a ≦ T is used as a bending portion for hemming bending performed by a roll forming machine on the downstream side of the second roll forming machine. It is characterized in that it is used to perform hemming bending roll forming.

  A roll forming apparatus according to an eighth aspect is the roll forming apparatus according to any one of the fourth to seventh aspects, wherein the plate is disposed on the downstream side of the second roll forming machine and supplied from the upstream side. The inner bent surface formed by bending a high strength steel sheet having a thickness T from a bending angle by the second roll mold to a smaller bending angle and roll forming so that the radius becomes a ≦ T by a second roll forming machine. A third roll forming machine for mounting a third roll mold provided with a holding portion for positioning and holding the arc A2, and a downstream side of the third roll forming machine, the upstream side leaving the inner bending surface arc A2 A fourth roll forming machine for forming the high strength steel sheet supplied from the U-shape and mounting a fourth roll mold provided with a holding portion for positioning and holding the inner curved surface arc A2, and the fourth roll Under the molding machine The high tensile strength of the plate thickness T supplied from the upstream side is provided with a fifth roll mold comprising a press roll mold disposed on the side and having a pair of cylindrical surfaces disposed in parallel with a 2T gap. A fifth roll forming machine that presses the inner curved surface arc A2 left on the steel plate with a pair of pressing roll dies, and the second roll forming machine is roll-formed so that the radius is a ≦ T. The inner bending surface arc A2 is positioned and held by the holding portion of the third roll type, and the external force applied to the inner bending surface arc A2 by being positioned and held by the holding portion of the fourth roll type is eliminated. It is used for a bending part of hemming bending performed in a molding machine.

  A roll forming apparatus according to a ninth aspect is the roll forming apparatus according to the eighth aspect, wherein, in the third roll forming machine, an inner bending surface arc A2 formed by the second roll forming machine is used as the third roll. By the second roll forming machine, the inner bending arc F1 having the radius f having the relationship of inner bending arc A1 <inner bending arc F1 provided in the third roll mold and held in the holding portion of the mold. Two inner bending surface arcs F2 extending from both ends of the inner bending surface arc A2 roll-formed so that the radius is a ≦ T are formed, and the bending angle is extended from the inner bending surface arc A2. Roll forming is performed so as to have an angle formed by two extending portions provided at the same position as the tangent to the tip of the inner bending surface arc F2.

  The roll forming apparatus according to a tenth aspect is the roll forming apparatus according to the eighth or ninth aspect, wherein the inner bending surface arc A2 or the outer bending surface arc B is set in the fourth roll forming machine. The two inner bending surface arcs F2 formed by the third roll molding machine are rolled into an arc having a radius a that is a ≦ T and the same as the inner bending surface arc A2. It is characterized by being formed into a U shape having a semicircular arc having a radius a.

  A roll forming apparatus according to claim 11 is the roll forming apparatus according to claim 8 or claim 10, wherein the high strength steel sheet is formed in a U shape by a fourth roll mold of the fourth roll forming machine. Is formed in a U-shape while rotating a pressing roll mold having a pair of cylindrical surfaces of the fifth roll mold when the is inserted into the fifth roll mold of the fifth roll molding machine arranged on the downstream side. The tensile strength steel sheet is sequentially pressed from the side surface, and hemming bending roll forming is performed using a semicircular arc having a radius of a ≦ T as an extension.

A processing method according to claim 12 is a processing method of bending a high strength steel plate having a thickness T of 1.6 mm or less by roll forming with a radius of the thickness T or less, the high strength steel plate being A first roll forming machine equipped with a first roll mold having a first upper mold for inner bending and a first lower mold for outer bending, and rolls the high strength steel sheet supplied from the first roll mold. A second roll forming machine having a second roll mold having a second inner mold for inner bending and a second lower mold for outer bending, and a first upper mold for inner bending of the first roll mold. And the first lower mold for outer bending, and the bending angle for bending the high strength steel plate formed on the roll forming surface of the second upper mold for inner bending and the second lower mold for outer bending, respectively. Formed at the same angle, the first upper for bending the inside of the first roll type A roll forming apparatus in which the radius c of the inner bending arc C1 formed on the inner bending arc C1 is set to 2T ≦ c ≦ 4 mm, and the radius a of the inner bending arc A1 in the second inner bending upper mold is set to a ≦ T. The high tensile strength steel plate is bent by roll forming with a radius equal to or less than the plate thickness T, and the high tensile strength steel plate supplied from the first roll mold is roll formed with the second roll mold. The bending moment generated by pressing the surface contact portion between the outer bending surface of the second lower die and the outer bending surface of the second lower die and the inner bending arc A1 in the second upper die for inner bending is suppressed. .

  A processing method according to a thirteenth aspect is the processing method according to the twelfth aspect, wherein the radius is a ≦ T through the inner bending arc A1 in the second inner bending upper mold of the second roll forming machine. The inner bending surface arc A2 of the high-strength steel sheet roll-formed so as to become a hemming-bending roll-forming process using the bending part of the hemming bending performed in the roll-forming machine downstream of the second roll-forming machine It is characterized by having performed.

  A processing method according to claim 14 is the processing method according to claim 12 or 13, wherein the processing method according to claim 12 or 13 is disposed on the downstream side of the second roll forming machine and has a high tensile strength with a plate thickness T supplied from the upstream side. The steel sheet is bent from the bending angle of the second roll mold to a smaller bending angle, and the inner bending surface arc A2 formed by the second roll forming machine so that the radius is a ≦ T is positioned and held. A third roll forming machine equipped with a third roll mold provided with a holding part, and the downstream side of the third roll forming machine, the above-mentioned supplied from the upstream side leaving the inner bending surface arc A2 A fourth roll forming machine for forming a high strength steel sheet into a U-shape and mounting a fourth roll mold provided with a holding part for positioning and holding the inner bending surface arc A2, and a downstream side of the fourth roll forming machine Placed in Both were provided with the 5th roll type | mold which consists of a press roll type | mold which has a pair of cylindrical surfaces arrange | positioned in parallel with the 2T gap | interval, and was left in the said high strength steel plate of the board | plate thickness T supplied from the upstream. A fifth roll forming machine that presses the inner bending surface arc A2 with a pair of pressing roll dies, and the inner bending surface arc A2 is roll-formed by the second roll forming machine so that the radius is a ≦ T. Is positioned and held by the third roll-type holding portion, and the external force applied to the inner bending surface arc A2 by being positioned and held by the fourth roll-type holding portion is eliminated, and is performed by the fifth roll forming machine. A roll forming apparatus for hemming bending is used to perform the hemming bending roll forming process on the high strength steel sheet.

According to the roll mold of claim 1, the material that is bent through the roll mold is a high-strength steel plate (high-tensile material), and its thickness (plate thickness) is regulated to 1.6 mm or less. ing.
This is because even if the inner bending surface of the high tensile strength steel plate has the same bending radius, as the wall thickness (thickness) increases, the bending radius of the outer bending surface increases and the elongation of the outer bending surface increases and cracking occurs. It is because it becomes easy to generate | occur | produce.
For this crack, the effect of the thickness (plate thickness) can be suppressed by regulating the thickness (plate thickness) of the high strength steel sheet to 1.6 mm or less, which is practical for reducing the weight. .

Moreover, in order to roll-form a high strength steel sheet with a bending radius equal to or less than the wall thickness (sheet thickness), the roll mold used here is a pair of first upper molds for inner bending that process the plane of the high strength steel sheet. A first roll mold having an outer bending first lower mold, a pair of inner bending second upper molds and a second outer bending second lower mold for processing the high strength steel sheet supplied from the first roll mold. It consists of a roll type.
Then, the first upper mold for inner bending, the first lower mold for outer bending, the second upper mold for inner bending of the second roll mold, and the second lower mold for outer bending, which are configured as described above, are used. The bending angle for bending the high tensile strength steel sheet is formed at the same bending angle.
Further, the inner bending arc C1 for bending the high tensile strength steel plate formed in the first upper die for inner bending of the first roll type has a radius c of 2T ≦ c ≦ 4 mm (T: wall thickness (plate thickness)). ), And the inner bending arc A1 for bending the high strength steel plate formed on the second upper die for inner bending of the second roll type has a radius a set to a ≦ T.

Usually, when a flat plate of a high strength steel plate is roll-formed by a first upper die for inner bending and a first lower die for outer bending, two points that receive the high strength steel plate of the first lower die for outer bending are fulcrums. Thus, a contact point of the inner bending arc C1 provided in the first inner bending upper die for bending the high strength steel plate acts as an action point for the high strength steel plate, and a bending moment is generated.
Due to this bending moment, the front side of the action point that the high strength steel sheet receives is extended across the action point, and the radius c of the inner bending arc C1 provided in the first inner bending die for bending the high strength steel sheet. If c is set to c ≦ T and roll forming is performed, the extension of the high-strength steel sheet cannot follow the front side of the action point, and cracking occurs reliably.
However, by setting the radius c of the inner bending arc C1 for bending the high strength steel plate to 2T ≦ c and using a high strength steel plate having a wall thickness (plate thickness) of 1.6 mm or less, the In the roll forming of the tensile strength steel plate, the elongation of the high strength steel plate follows the bending moment, so that cracking can be prevented.

Further, the high tensile strength steel plate is roll-formed by a first roll die in which the radius c of the inner bending arc C1 provided in the first inner bending die for bending the high tensile strength steel plate is set to c ≦ 4, An inner bending surface arc (hereinafter referred to as an inner bending surface arc C2) formed by the inner bending arc C1 and a bending angle provided in the first roll mold are given. Then, the high strength steel plate is put into the second roll mold.
In the second roll mold, as described above, the bending angle for bending the high-strength steel plate of the second upper mold for inner bending and the second lower mold for outer bending is formed at the same bending angle as that of the first roll mold. .
Therefore, the high-strength steel sheet formed and thrown at the same angle as the first roll mold and the second roll mold includes the plane of the extended portion extended from the inner bending surface arc C2 of the high-strength steel sheet and the second roll. When the outer bending plane of the second lower mold for outer bending of the mold comes into surface contact, the inner bending arc A1 provided at the tip of the second inner bending upper mold presses the inner bending arc C2. It is clamped between the second upper mold for inner bending and the second lower mold for outer bending.
By this clamping and the inner bending arc A1 pressing the arc, it is possible to suppress the generation of a large bending moment as when pressing the flat plate.
Thereby, the extension which generate | occur | produces on the front side of the high strength steel plate which inner side circular arc A1 presses can be suppressed.

Furthermore, the plane of the extended portion extended from the inner bending surface arc C2 of the high tensile strength steel plate and the outer bending plane of the second lower die for outer bending of the second roll type come into surface contact, and the inner bending first 2 When the inner bending arc A1 provided at the tip of the upper die presses the inner bending surface arc C2, the high strength steel sheet comes into surface contact with the second roll mold that rotates the pressure pressing the high strength steel sheet. Will be received on the side.
The pressure for pressing the high strength steel sheet is the same as the pressure for pressing the inner bending surface arc C2 by the inner bending arc A1 provided at the tip of the second inner bending upper die. A pressure that presses in the direction of the center of bending is generated, and this pressing pressure works to compress the material of the high-strength steel sheet while compressing the material toward the center of bending.
As a result, the inner bending surface arc C2 formed by the first roll mold of the high tensile strength steel plate is an inner bending surface arc having the same radius a as the inner bending arc A1 in the second roll mold (hereinafter referred to as inner bending surface arc A2). At the same time, the outer bent surface arc of the high strength steel plate facing the inner bent surface arc A2 is formed on the outer bent surface arc having no crack with a radius of a + T by the above-described roll forming and drawing. (Hereinafter referred to as the outer bending surface arc B) can be formed.
As described above, the radius c of the inner bending surface arc C2 of the high tensile strength steel plate is initially 2T ≦ c ≦ 4, together with the conditions for using the first roll type and the second roll type having the same desired bending angle. Two-stage roll forming is performed in which the first roll mold is used for roll forming, and then the second roll mold is used to perform roll forming with a desired bending radius equal to or less than the thickness (plate thickness) T of the high strength steel sheet. Thus, roll forming that does not generate cracks in the outer bending surface arc B can be made possible even with a desired bending radius of a wall thickness (plate thickness) T or less with respect to a high tensile strength steel plate having a small elongation rate.

Next, according to the roll type according to claim 2, the second roll type includes the inner bending arc C1 and the outer bending first lower die formed in the first upper die for inner bending of the first roll die. For the inner side bending of the second roll type smaller than the radius of the inner bending surface arc C2, the outer bending surface arc S formed on the opposite side of the inner bending surface arc C2 and the inner bending surface arc C2 of the high strength steel plate formed by Since the inner bending arc A1 formed on the second upper die and the second lower die for outer bending are roll forming while drawing, the inner side formed on the second upper die for inner bending of the second roll die. A plane continuous from the arc A1 for bending and a plane formed in the second lower mold for outer bending are formed by forming the inner bending surface arc C2 and the outer bending surface arc S of the high strength steel sheet into a straight line and extending straight. Remaining high tensile strength steel plate material It is to carry out the meat gathering to gather while compressing toward the center of the bottom.
Thereby, roll forming which does not generate | occur | produce a crack in the outer side bending surface circular arc B can be enabled with respect to the high tensile strength steel plate with a small elongation rate, even if it is the desired bending radius below the thickness (plate thickness) T.

Next, according to the roll die according to claim 3, when the high strength steel plate is roll-formed through the second roll die, the outer bending surface arc B formed on the outer side of the high strength steel plate and the outer bending. A gap D is formed between the corners of the second lower mold for use.
According to this, since the bending angle of the high-strength steel sheet that has passed through the first roll mold is formed at the same angle as the bending angle of the second roll mold, the high-strength steel sheet is inserted into the second roll mold. In the roll forming process, the outer bending plane of the extension portion extending from the inner bending surface arc C2 of the high strength steel sheet and the outer bending plane of the second lower bending die are in surface contact with each other. By being pressed sequentially by the two upper molds, the second roll mold is easily formed by roll forming in the direction of the gap D provided in the direction of the center of bending of the high strength steel sheet and roll forming. The outer bending surface arc B can be formed without breaking.

Next, according to the roll forming apparatus of the fourth aspect, since the roll forming apparatus uses the roll mold in the first aspect as it is, the effect in the first aspect is inherited as it is.
And in a roll forming apparatus, in order to perform roll forming with the desired bending radius below the thickness (plate thickness) T of a high strength steel plate, the 1st roll type | mold with which a 1st roll forming machine is mounted | worn, and a 2nd roll Only the shape of the second roll mold to be mounted on the forming machine is designed, and rolls an extra device or member for roll forming with a desired bending radius equal to or less than the thickness (plate thickness) T of the high strength steel plate. There is no need to add to the molding equipment.
Therefore, the roll forming apparatus of the present invention can be used as it is simply by replacing the roll mold of the roll forming apparatus used conventionally. Thereby, roll shaping | molding can be performed by the same operation | work as the normal operation | work performed with the conventional roll forming apparatus.
These means that extra labor and cost are not required for roll forming at a desired bending radius equal to or less than the wall thickness (plate thickness) T of the high tensile strength steel plate J.

  Next, according to the roll forming apparatus of the fifth aspect, since the roll forming apparatus uses the roll mold in the second aspect as it is, the effect in the second aspect can be taken over as it is.

  Next, according to the roll forming apparatus of the sixth aspect, since the roll forming apparatus uses the roll mold in the third aspect as it is, the effect in the third aspect can be taken over as it is.

Next, according to the roll forming apparatus of the seventh aspect, the inner roll surface arc A <b> 2 of the high strength steel plate that has been roll-formed by the second roll forming machine so that the predetermined angle and the radius a are a ≦ T, Hemming-bending roll forming is performed by using a bending part for hemming bending performed by a roll forming machine on the downstream side of the forming machine.
The inside bending surface arc A2 of the high strength steel sheet roll-formed with a predetermined angle and radius a by a ≦ T by this second roll forming machine is input with the bending angle of the high strength steel sheet input to the second roll forming machine. The bending angle of the second roll mold is the same bending angle, the plane of the extended portion extended from the inner bending surface arc C2 of the high strength steel sheet, and the outer bending of the second lower mold for outer bending of the second roll mold The surface is brought into surface contact with the material, and the material is pulled together and drawn by compression toward the center of bending of the high strength steel sheet, and the inner bending surface arc C2 of the high strength steel sheet is smaller than the radius of the inner bending surface arc C2. Since the roll forming is performed while drawing the inner bending surface arc A2, the material of the high tensile strength steel plate that is not stretched is formed in the surface contact portion while forming the inner bending surface arc C2 and the outer bending surface arc S of the high strength steel plate in a straight line. High strength steel sheet bending Work also joined sufficient meat gathering to perform the meat gathering to gather while compressing toward the heart is being carried out.
By using the inner bending surface arc A2 of the high strength steel plate formed in this way for the bending portion of the hemming bending, it is possible to perform the roll forming of the hemming bending without a crack.

  Next, according to the roll forming apparatus of the eighth aspect, the inner bending surface arc A2 roll-formed by the second roll forming machine so that the radius a is a ≦ T is the third roll forming machine mounted on the third roll forming machine. The fifth roll is positioned and held by the roll-type holding unit, and is externally applied to the inner bending surface arc A2 by being mounted on the fourth roll molding machine and positioned and held by the fourth roll-type holding unit. Even if it is put into the final step of hemming bending performed by a molding machine, roll forming of hemming bending without cracks can be performed.

Next, according to the roll forming apparatus according to claim 9, in the third roll forming machine, the high tensile strength steel sheet supplied from the upstream side is subjected to an external force on the inner bending surface arc A2 formed by the second roll forming machine. In order to perform bending from the bending angle by the second roll mold to the next bending angle without adding, the inner bending surface arc A2 formed by the second roll forming machine is held in the holding portion of the third roll mold, A second roll forming machine roll-forms radius a to a ≦ T by an inner bending arc F1 having a radius f having a relationship of inner bending arc A1 <inner bending arc F1 provided in the three-roll mold. Two inner bending surface arcs F2 extending from both ends of the inner bending surface arc A2 are formed, and the next bending angle is tangent to the tip of the inner bending surface arc F2 extending from the inner bending surface arc A2. At the same position And to the roll forming so that One of the extending portion is an angle.
In this way, in order to bend from the bending angle by the second roll mold to the next bending angle, the inner bending surface arc A2 is held by the holding portion of the third roll mold, and the inner bending surface arc A2 is not bent but is different. By providing the bending portion at the place, the inner bending surface arc A2 can be protected from an external force for bending to the next bending angle.

Next, according to the roll forming apparatus of the tenth aspect, in the fourth roll forming machine, the high strength steel sheet supplied from the upstream side is subjected to an external force on the inner bending surface arc A2 left by the third roll forming machine. In order to form a U-shape with the fourth roll mold without adding, the inner bending surface arc A2 or the outer bending surface arc B was held in the holding portion of the fourth roll mold and formed by the third roll molding machine. The two inner bending surface arcs F2 are roll-formed into an arc having a radius a that is the same as the inner bending surface arc A2, and a U shape having a semicircular arc with a radius a is formed.
When this inner bending surface arc F2 is roll-formed into an arc having a radius a with the same a ≦ T as the inner bending surface arc A2 in the fourth roll type, the material of the inner bending surface arc F2 is a rotating fourth roll. Because the die is pressed to the existing inner bending surface arc A2 side held by the holding part of the fourth roll die and formed into the same radius a as the inner bending surface arc A2, it overcomes the extending force of the material. Cracking can be prevented.
In this way, a semicircular arc having a radius a can be formed while protecting the existing inner bending surface arc A2.

Next, according to the roll forming apparatus of the eleventh aspect, the fifth roll forming machine in which the high strength steel plate formed in a U shape by the fourth roll mold of the fourth roll forming machine is disposed on the downstream side. When put into the 5-roll mold, the pressing roll mold having a pair of cylindrical surfaces of the fifth roll mold is sequentially pressed from the side against the high-strength steel plate formed in this U shape while rotating, Hemming roll forming is performed using a semicircular arc of radius a satisfying a ≦ T as an extension.
This fifth roll mold has a pair of cylindrical surfaces that rotate and press the side of the high-strength steel sheet in order from the side surface to cause compression and fleshing of the high-strength steel sheet in the bending direction. Therefore, roll forming of hemming bending can be performed without causing cracking in the bending portion of hemming.

Next, according to the processing method which concerns on Claim 12, using the 1st roll forming machine and 2nd roll forming machine of the roll forming apparatus described in Claim 4, it is the 1st which has the same desired bending angle. Along with the conditions of using the 1 roll type and the 2nd roll type, the roll is first rolled by the first roll type of the first roll forming machine so that the radius c of the inner bending surface arc C2 of the high strength steel plate becomes 2T ≦ c ≦ 4. Processing in which two-stage roll forming is performed, in which the second roll mold of the second roll forming machine is used and then roll forming is performed with a desired bending radius equal to or less than the thickness (plate thickness) T of the high-strength steel plate. Is the method.
Therefore, by taking over the effect of claim 4 as it is, a method of performing two-stage roll forming on a high strength steel sheet having a small elongation rate even if the desired bending radius is less than the wall thickness (sheet thickness) T. It is possible to provide a roll forming method that does not cause cracks in the bending surface arc B.

Next, according to the processing method which concerns on Claim 13, using the 1st roll forming machine and 2nd roll forming machine of the roll forming apparatus described in Claim 4, it is the 1st which has the same desired bending angle. Along with the conditions of using the 1 roll type and the 2nd roll type, the roll is first rolled by the first roll type of the first roll forming machine so that the radius c of the inner bending surface arc C2 of the high strength steel plate becomes 2T ≦ c ≦ 4. The two-stage forming is then performed using the second roll mold of the second roll forming machine, and then roll forming with a bending radius a satisfying a ≦ T which is equal to or less than the thickness (plate thickness) T of the high strength steel plate. This is a processing method of performing hemming bending roll forming by using the inner bending surface arc A2 formed by roll forming in a bending portion of hemming bending performed by a roll forming machine downstream of the second roll forming machine.
The bending of the hemming bend is performed by using the inner bending surface arc A2 sufficiently brought close to the bending portion of the arc by the first roll forming machine and the second roll forming machine of the roll forming apparatus as the bending portion of the hemming bend. It is possible to provide a processing method for performing roll forming of ming bending that does not cause cracks in the portion.

  And, according to the processing method according to claim 14, the inner bending surface arc A2 roll-formed with the radius a of a ≦ T by the second roll forming machine is used for the bending portion of the hemming bending. It is positioned and held by the holding part of the third roll mold mounted on the third roll molding machine, and is positioned and held by the holding part of the fourth roll mold mounted on the fourth roll molding machine and applied to the inner bending surface arc A2. By the method of eliminating the external force, it is possible to provide a processing method for performing hemming bending roll forming without cracking even if it is put into the final step of hemming bending performed by the fifth roll forming machine.

It is a top view of the roll forming apparatus according to the first embodiment. It is the side view seen from the side of the 1st roll type of the 1st roll forming machine. It is the side view seen from the side of the 2nd roll type of the 2nd roll forming machine. It is explanatory drawing explaining the state which roll-forms the flat plate of a high strength steel plate to a predetermined angle by a predetermined bending radius using the 1st roll type | mold of a 1st roll forming machine. It is explanatory drawing explaining the test result for calculating | requiring the radius c which can be shape | molded by the roll shaping | molding from a flat plate without a crack. It is explanatory drawing explaining the shaping | molding result from the flat plate in case the relationship between plate | board thickness T and the radius c is c = 2T. It is explanatory drawing explaining the shaping | molding result from the radius c to the radius a in the same angle in case of plate | board thickness T = 1.6mm. It is explanatory drawing explaining the shaping | molding result from the radius c to the radius a in the same angle in case of plate | board thickness T = 1.6mm. It is explanatory drawing explaining the shaping | molding result from the radius c to the radius a in the same angle in case of plate | board thickness T = 1.4mm. It is explanatory drawing explaining the shaping | molding result from the radius c to the radius a in the same angle in case of plate | board thickness T = 1.2mm. It is explanatory drawing explaining the shaping | molding result from the radius c to the radius a in the same angle in case of plate | board thickness T = 1.0mm. It is explanatory drawing explaining in which position range of a 2nd roll type | mold a high tensile strength steel plate is roll-formed. It is sectional drawing explaining how the high strength steel plate shape | molded by the 1st roll type | mold is roll-formed by the 2nd roll type | mold. It is the three-dimensional figure which analyzed the roll forming trace of the high tensile strength steel plate taken out from the process of roll forming with the 2nd roll type, and expressed it on the diagram, and showed the direction of operation. It is a top view of the roll forming apparatus according to the second embodiment. It is the side view seen from the side of the 3rd roll type of the 3rd roll forming machine. It is the side view seen from the side of the 4th roll type of the 4th roll forming machine. It is the side view seen from the side of the 5th roll type of the 5th roll forming machine. It is explanatory drawing explaining the hemming shaping | molding result in case plate | board thickness T = 1.6mm.

Hereinafter, a first embodiment in which the present invention is applied to a roll forming apparatus will be described in detail with reference to the drawings.
In the first embodiment, a high strength steel sheet having a wall thickness (plate thickness) T of 1.6 mm or less is roll-formed at a predetermined angle with a minimum radius of wall thickness (plate thickness) T or less without causing cracks. A roll mold, a roll forming machine, and a roll forming apparatus will be described.
First, a schematic configuration of the roll forming apparatus 1 according to the first embodiment will be described with reference to FIG. Here, FIG. 1 is a top view of the roll forming apparatus according to the first embodiment.
As shown in FIG. 1, the roll forming apparatus 1 includes a first roll forming machine 4 connected to a first speed reducer 3 via a first rotary connecting machine 2 and a second rotary connecting machine 5. A second roll forming machine 7 connected to the second speed reducer 6, a third roll forming machine 10 connected to the third speed reducer 9 via a third rotary connecting machine 8, and a fourth rotary connecting machine. The fourth roll forming machine 13 connected to the fourth speed reducer 12 through 11 and the fifth roll forming machine 16 connected to the fifth speed reducer 15 through the fifth rotary connecting machine 14 are the bases. 17 is disposed.
The second speed reducer 6 and the first speed reducer 3 are connected by a sixth rotary connecting machine 18, the first speed reducer 3 and the fifth speed reducer 15 are connected by a seventh rotary connecting machine 19, and a fifth The speed reducer 15 and the fourth speed reducer 12 are connected by an eighth rotary coupler 20, the fourth speed reducer 12 and the third speed reducer 9 are connected by a ninth rotary coupler 21, and the third speed reducer. 9 is connected to a motor 23 by a tenth rotary connecting machine 22 so that the first roll forming machine 4 to the fifth roll forming machine 16 can be operated.
Further, the roll forming apparatus 1 is provided with an auxiliary equipment 24 for supplying a material to be roll-formed as an auxiliary equipment and a next process equipment 25 for performing drilling, cutting, bending, etc., and continuously manufactures one part. It has a configuration.

Then, the structure of the 1st roll forming machine 4 and the 2nd roll forming machine 7 which are the center of this invention is demonstrated based on FIG.1, FIG.2, FIG.3.
Here, FIG. 2 is a side view seen from the side of the first roll mold of the first roll molding machine, and FIG. 3 is a side view seen from the side of the second roll mold of the second roll molding machine.
As shown in FIGS. 1 and 2, the first roll forming machine 4 includes a first roll stand R <b> 26 and a first roll stand L <b> 27 erected from the base 17.
The first roll stand R26 and the first roll stand L27 include a first shaft body 30 on which one inner bending first upper mold 29 constituting the first roll mold 28 is attached, and the other outer bending first. A first shaft lower body 32 to which a lower mold 31 is attached is mounted.
The first upper shaft body 30 and the lower first shaft body 32 are provided with a desired gap in the first upper bending die 29 for inner bending and the first lower bending die 31 for outer bending, and the first roll stand R26 and the first roll. It is fixed so as to be rotatable with respect to the stand L27.
The first roll forming machine 4 configured as described above is in an operable state when the lower first shaft body 32 is connected to the first rotary connecting machine 2.
As shown in FIGS. 1 and 3, the second roll forming machine 7 includes a second roll stand R <b> 33 and a second roll stand L <b> 34 erected from the base 17.
The second roll stand R33 and the second roll stand L34 include a second shaft upper body 37 to which one inner bending second upper mold 36 constituting the second roll mold 35 is attached, and the other outer bending first. 2 A lower shaft body 39 to which a lower mold 38 is attached is mounted.
The second upper shaft body 37 and the second lower shaft body 39 are provided with a desired gap between the second inner bending upper die 36 and the second outer bending lower die 38, and the second roll stand R33 and the second roll. It is fixed so as to be rotatable with respect to the stand L34.
The second roll forming machine 7 configured as described above is in an operable state when the second lower shaft body 39 is connected to the second rotary connecting machine 5.

Then, the structure and function of the 1st roll type | mold 28 attached to the 1st roll molding machine 4 are demonstrated based on FIG.
As described above, the first roll mold 28 composed of the first upper mold 29 for inner bending and the first lower mold 31 for outer bending is the second roll molding disposed on the downstream side of the first roll molding machine 4. In the machine 7, for the high strength steel plate J, the roll can be formed without causing cracks at a predetermined angle and a minimum radius (thickness) T or less of a desired thickness (plate thickness) T. It is a roll mold for performing pre-processing roll forming.
The high strength steel sheet J roll-formed from a flat plate by the first roll die 28 is bent at the same angle as shown in the enlarged view of the k portion corresponding to the final step of the roll forming performed in the first roll die 28 of FIG. The inner bending first upper die 29 and the outer bending first lower die 31 having an angle α are sandwiched between the bending strength α and the bending strength α of the high strength steel plate J.
This bending angle α is attached to the second roll forming machine 7 in order to prevent cracking of the high strength steel sheet J roll-formed by the second roll forming machine 7 arranged on the downstream side of the first roll forming machine 4. The bending angle α formed on both the second upper die 36 for inner bending and the second lower die 38 for outer bending of the second roll die 35 must be the same.
And as shown in the K section enlarged view of Drawing 2, radius c is 2T <= c <= 4 (T: thickness (thickness) of high strength steel plate J) at the tip of inner upper 1st upper mold 29 An inner bending arc C1 is set.
Thus, the high strength steel plate J roll-formed by the first roll die 28 has the same radius c as the radius c of the inner bending arc C1 provided at the tip of the inner bending first upper die 29. The inner bending surface arc C2 having a range of 2T ≦ c ≦ 4 is roll-formed.
At this time, an outer bending surface arc S having a radius s = c + T and having no crack is formed on the outer bending surface of the high strength steel plate J facing the inner bending surface arc C2 by the roll forming described above.

Then, the structure and function of the 2nd roll type | mold 35 attached to the 2nd roll forming machine 7 arrange | positioned in the downstream of the 1st roll forming machine 4 are demonstrated based on FIG.
As described above, the second roll die 35 includes the inner bending second upper die 36 and the outer bending second lower die 38.
As shown in the enlarged view of the portion m corresponding to the final step of the roll forming performed in the second roll mold 35 in FIG. 3, the second upper mold 36 for inner bending and the second lower mold 38 for outer bending that bend the high strength steel sheet J. Both bending angles are the same as the bending angle α.
The bending angle α of both the second upper die 36 for inner bending and the second lower die 38 for outer bending of the second roll die 35 is the first upper die for inner bending of the first roll die 28 as described above. 29 and the outer bending first lower die 31 are formed at the same angle as the bending angle α.
Further, as shown in the enlarged view of the M part in FIG. 3, the radius a is set to a ≦ T (T: the thickness (thickness) of the high strength steel plate J) at the tip of the second upper mold 36 for inner bending. An inner bending arc A1 is provided.
The function of the 2nd roll type | mold 35 comprised in this way is demonstrated.
First, the high strength steel sheet J provided with the bending angle α and the inner bending surface arc C2 formed by roll forming on the upstream side of the second roll forming machine 7 is rotated by the second roll forming machine 7. Supplied to the roll mold 35.
A plane j2 of the extended portion j1 extending at a bending angle α from the inner bending surface arc C2 of the supplied high strength steel plate J is formed at the same bending angle α as that of the supplied high strength steel plate J. The two-roll die 35 comes into surface contact with the outer bending plane 38A of the second lower die 38 for outer bending.
Then, the inner bending arc A1 provided at the tip of the second inner bending upper die 36 abuts against the inner bending surface arc C2 of the high strength steel plate J while rotating, and the inner bending surface arc C2 becomes the outer bending second arc. 2. Press in the direction of an intersection 40 (see FIG. 3) described later of the lower mold 38.
Due to this surface contact and pressing, the material bending and drawing by compression in the center direction of bending of the high strength steel plate J occurs, so that the inner bending surface arc C2 of the high strength steel plate J becomes the inner bending arc A1. Is rolled into an inner bending surface arc A2 having the same radius a. (See Figure 13)
At this time, on the outer bending surface of the high strength steel plate J facing the inner bending surface arc A2, an outer bending surface arc B having no radius b = a + T is formed by the above-described roll forming and drawing. Is done.
The second roll die 35 has an intersection where two planes of an inner bending arc A1 and an outer bending second lower die 38 provided at the tip of the inner bending second upper die 36 intersect at a predetermined angle. A gap D formed with the portion 40 is provided, and serves as an auxiliary portion that facilitates the above-described meat gathering and drawing.

Here, the reason why the radius c of the inner bending arc C1 and the inner bending arc C2 is set to 2T ≦ c ≦ 4 will be described with reference to FIGS.
Here, FIG. 4 is an explanatory diagram for explaining a state in which a flat plate of a high strength steel plate is roll-formed at a predetermined angle with a predetermined bending radius using the first roll mold of the first roll forming machine, and FIG. FIG. 6 is an explanatory diagram for explaining a test result for obtaining a radius c that can be formed without cracking by roll forming from a flat plate. FIG. 6 is a drawing from a flat plate when the relationship between the plate thickness T and the radius c is c = 2T. FIG. 7 is an explanatory view for explaining the result, FIG. 7 is an explanatory view for explaining the forming result from the radius c to the radius a at the same angle when the plate thickness T = 1.6 mm, and FIG. FIG. 9 is an explanatory diagram for explaining the forming result from the radius c to the radius a at the same angle in the case of 6 mm. FIG. 9 shows the forming result from the radius c to the radius a at the same angle when the plate thickness T = 1.4 mm. FIG. 10 is a diagram illustrating the radius from the radius c at the same angle when the plate thickness T = 1.2 mm. Explanatory view illustrating a molding results to, FIG. 11 is an explanatory view illustrating a molding results to radius a the radius c of the same angle in the case of a plate thickness T = 1.0 mm.

First, the reason for setting 2T ≦ c will be described with reference to FIGS. 4 and 5.
As shown in the explanatory diagram (4-I) of FIG. 4, in order to roll-form the flat plate of the high-strength steel plate J at a predetermined angle with a predetermined bending radius, the first upper mold for inner bending of the first roll mold 28 is used. 29 and the outer lower bending first lower die 31, the inner bending first upper die 29 contacts the point L 1 of the high strength steel plate J and the outer bending first lower die 31 is made of the high strength steel plate J. It abuts on the points L2 and L3.
That is, the relationship is that the bending moment by three points L2, L1, and L3 works, and the maximum bending moment works at the point L1.
When the distance between the points L2 and L1 and the distance between the points L1 and L3 are long, the maximum bending moment at the point L1 is large, and when the distance is short, the maximum bending moment at the point L1 is small.
If roll forming is continued as it is, as shown in the explanatory diagram (4-II) of FIG. 4, the high strength steel plate J is supported at points L2 and L3 of the high strength steel plate J with which the first lower die 31 for outer bending comes into contact. Then, the bending starts from the point L1 of the high tensile strength steel plate J with which the first upper bending die 29 is in contact.
The relationship of bending from the point L1 of the high strength steel sheet J supported by the point L2 and the point L3 of the high strength steel sheet J with which the first lower bending die 31 abuts, and the first upper mold 29 for inner bending is in contact 4 is maintained as it is as shown in the explanatory diagram (4-III) of FIG. 4, and continues until the roll forming is completed as shown in the explanatory diagram (4-IV) of FIG.
By this roll forming, the bending stress is concentrated at the point L4 facing the point L1 shown in the explanatory diagrams (4-I) to (4-IV) of FIG. Thus, elongation occurs in the directions of arrows L5 and L6.
For this reason, the elongation at the point L4 is the largest, and therefore, in the high tensile strength steel sheet J having a small elongation, cracks occur at the point L4.
This crack is related to the radius c of the inner bending arc C1 provided at the tip of the inner bending first upper die 29. If the radius c is large, the crack is not generated, and if the radius c is small, the crack is generated. Occur.

Therefore, what is the value of the radius c of the inner bending arc C1 to determine whether cracking occurs or not, and the tip of the first upper die 29 for inner bending using the first roll die 28 of the first roll forming machine 4 is used. The test was conducted by changing the radius c of the inner bending arc C1 provided on the inner bending arc. The result is shown in FIG.
In the test shown in FIG. 5, the thickness (plate thickness) T of the high-strength steel plate J used in the present invention is 1.6 mm or less, and the thicker the thickness (plate thickness) is empirically, the easier it is to break. Then, using the high tensile strength steel plate J having a wall thickness (plate thickness) of 1.6 mm, the inner bending arc C1 is applied to four types of samples having tensile strengths of 980 MPa (megapascal), 1180 MPa, 1270 MPa, and 1470 MPa, respectively. A roll molding test was performed by sequentially setting the radius c to 0.8 mm (0.5 T), 1.6 mm (1 T), and 3.2 mm (2 T).
As shown in FIG. 5, if the radius c of the inner bending arc C1 is 3.2 mm, which is twice the thickness (plate thickness) T, the result is that no cracks occur in any tensile strength sample. .
Further, when the radius c of the inner bending arc C1 is 1.6 mm which is the same as the wall thickness (plate thickness) T, cracking occurs when the tensile strength is 1180 MPa or more, and the radius c of the inner bending arc C1 is thick (plate). In the case of 0.8 mm which is 0.5 times T), cracks occur in any tensile strength sample.
That is, the result shown in FIG. 5 is that the radius c of the inner bending arc C1 is set to a value equal to or less than the wall thickness (plate thickness) T only by roll forming that relies solely on the elongation of the high strength steel plate J shown in FIG. It shows that roll forming without cracking is impossible.
However, according to the present invention, it is possible to roll-form the high strength steel plate J without cracking even with a bending radius equal to or less than the wall thickness (plate thickness) T.
That is, the first roll mold 28 and the second roll mold 35 having the same desired predetermined bending angle α are used, and the high-strength steel plate J is first desired with a bending radius at which no cracks are generated by the first roll mold 28. After roll forming to a predetermined bending angle α, it is possible by taking means for performing roll forming with a desired bending radius equal to or less than the thickness (plate thickness) T of the high strength steel plate J using the second roll die 35. It becomes.
For that purpose, first, what value should be used for the radius c of the inner bending arc C1 provided at the tip of the inner bending first upper die 29 of the first roll die 28, the flat high strength steel plate J It is necessary to set whether or not roll forming can be performed without breaking the desired bending angle α.
Therefore, from the result of FIG. 5 in which the thickness (plate thickness) T was set to 1.6 mm and the test was performed because the thicker (thickness) T of the high tensile strength steel plate J was easier to break than the thinner one, the inner side The radius c of the bending arc C1 is preferably 2T ≦ c.
Further, as a confirmation test, when the combination of the thickness (plate thickness) T of the high strength steel plate J and the radius c of the inner bending arc C1 is T = 1.4 mm, c = 2.8 mm, and T = 1. FIG. 6 shows the results of performing roll forming and testing for c = 2.4 mm in the case of 2 mm and c = 2.0 mm in the case of T = 1.0 mm.
As shown in FIG. 6, if the radius c of the inner bending arc C1 is twice the thickness (plate thickness) T, no cracks occur in any thickness (plate thickness) and any tensile strength samples. became.
As a matter of course, if the radius c of the inner bending arc C1 is more than twice the wall thickness (plate thickness) T, a roll that does not crack in any thickness (plate thickness) and any tensile strength sample. This means that molding can be performed, and it can be confirmed that 2T ≦ c is appropriate.
Thus, first, the radius c of the inner bending arc C1 is determined as 2T ≦ c.

Next, the reason for setting c ≦ 4 will be described.
The c ≦ 4 is an element that is necessary when the high-strength steel plate J is roll-formed in the second roll die 35.
This is because, in the first roll mold 28, when the radius c of the inner bending arc C1 is 2T ≦ c, roll forming that does not cause cracking in any thickness (plate thickness) and any tensile strength sample is performed. Although it turned out that it is possible, if the high strength steel sheet J roll-formed with 2T ≦ c in the first roll mold 28 is roll-formed in the second roll mold 35, cracks occur when the radius c exceeds a certain value. It is.
That is, when an inner bending surface arc C2 formed with a radius c greater than a certain value is roll-formed by an inner bending arc A1 having a radius a equal to or less than the wall thickness (plate thickness) T, the bent portion of the high strength steel plate J is illustrated. Since the same three-point support phenomenon as in the roll forming of the flat plate described in 4 occurs in the inner bending surface arc C2, cracking occurs.
That is, by the surface contact between the high strength steel plate J and the second roll die 35 with the same bending angle α and the inner bending surface arc C2 being pressed by the inner bending arc A1, compression of the high strength steel plate J toward the center of bending is performed. Cracks occur because the amount of material gathering and drawing formed cannot cover the elongation generated by the three-point support.

Therefore, if the radius c of the inner bending arc C1 provided at the tip of the inner bending first upper mold 29 of the first roll mold 28 is any value, it is cracked by roll forming with the second roll mold 35. A confirmation test was conducted to check whether or not this occurred.
First, the thickness (plate thickness) T of the high-strength steel plate J used in the present invention is 1.6 mm or less. (Thickness) A 1.6 mm high tensile strength steel plate J is used, and four types of tensile strengths of 980 MPa (megapascal), 1180 MPa, 1270 MPa, and 1470 MPa are prepared.
Since the minimum side of the radius c of the inner bending arc C1 provided at the tip of the inner bending first upper mold 29 of the first roll mold 28 is already determined to be 2T ≦ c, the inner bending arc C1. The roll c is sequentially set to 3.2 mm (2T), 6.4 mm (4T), and 9.6 mm (6T), and the radius c of the inner bending surface arc C2 is 3.2 mm (2T). Samples of 6.4 mm (4T) and 9.6 mm (6T) are sequentially prepared.
Subsequently, since the thickness (plate thickness) T of the above-described sample is 1.6 mm, the radius a of the inner bending arc A1 provided at the tip of the second inner mold 36 for inner bending of the second roll mold 35. When a is set to a = 1.6 mm and the above-described roll forming of the sample is sequentially performed, a crack occurs at a certain point. The result is shown in FIG.
As shown in FIG. 7, when the radius c of the inner bending arc C1 provided at the tip of the inner bending first upper die 29 of the first roll die 28 is 9.6 mm (6 T), any tensile strength can be cracked. It was confirmed that cracking occurred when the radius c was increased.
Therefore, from this result, the radius a of the inner bending arc A1 provided at the tip of the second inner bending upper mold 36 of the second roll die 35 is a ≦ T (T: the thickness (thickness of the high tensile strength steel plate J). In consideration of the use of a material having a thickness (plate thickness) T of the high strength steel plate J of 1.6 mm or less, the tip of the first upper die 29 for inner bending of the first roll die 28 is used. The maximum value of the radius c of the inner bending arc C1 provided is determined to be 4 mm or less, and is set to c ≦ 4.

Further, as a result of experience, the thicker (thickness) is easier to break, and thus the high-strength steel plate J having a thickness (thickness) T of 1.6 mm is used to increase the inside of the first roll mold 28. Although the radius c of the inner bending arc C1 provided at the tip of the first bending upper die 29 is set to 2T ≦ c ≦ 4, the high strength steel plate J having a wall thickness (plate thickness) T of 1.6 mm or less. Also, a confirmation test was performed to determine whether 2T ≦ c ≦ 4 is appropriate.
First, when the thickness (plate thickness) T of the high strength steel plate J is 1.6 mm, the radius c of the inner bending surface arc C2 is c = 3. Similarly, when the thickness (plate thickness) T is 1.4 mm, c = 2.8 mm, c = 4.0 mm, and the thickness (plate thickness). ) When T is 1.2 mm, c = 2.4 mm and c = 4.0 mm, and when the thickness (plate thickness) T is 1.0 mm, c = 2.0 mm and c = 4.0 mm. Prepare the sample formed in
Then, roll forming is performed by each of the second roll dies 35 in which the radius a of the inner bending arc A1 provided at the tip of the inner bending second upper die 36 is set to a = 0.5 mm. This is a method of observing and confirming whether or not a crack has occurred in the outer bending surface arc B shown in the enlarged view.
The results of the confirmation test by this method are shown in FIGS.
According to the results shown in FIGS. 8 to 11, no cracks occurred in any case.
From this result, according to the following roll forming method, cracks are generated in the outer bending surface arc B shown in the enlarged view of the M part of FIG. 3 even at a desired bending radius equal to or less than the thickness (plate thickness) T of the high strength steel plate J. It was confirmed that roll forming that does not occur is possible.
The method uses a condition in which the first roll mold 28 and the second roll mold 35 having the same desired predetermined bending angle α are used, and the radius c of the inner bending surface arc C2 of the high strength steel plate J is initially 2T ≦ roll forming is performed by the first roll mold 28 so that c ≦ 4, and then the second roll mold 35 is used to perform roll forming at a desired bending radius equal to or less than the thickness (plate thickness) T of the high strength steel plate J. This is a method of performing two-stage roll forming.
Thereby, the radius c of the inner bending arc C1 provided at the tip of the inner bending first upper die 29 of the first roll die 28 is a high tensile strength steel plate having a thickness (plate thickness) T of 1.6 mm or less. It was confirmed that 2T ≦ c ≦ 4 is appropriate for J.

Subsequently, the roll forming operation in which no crack is generated in the outer bending surface arc B shown in the enlarged view of the M part in FIG. 3 will be described with reference to FIGS. 2, 12 to 14.
Here, FIG. 12 is an explanatory diagram for explaining in which position range of the second roll type the high strength steel plate is roll-formed, and FIG. 13 is a diagram showing that the high strength steel plate formed by the first roll type is the second roll type. FIG. 14 is a cross-sectional view for explaining how to form a roll according to FIG. 14, and FIG. FIG.

First, based on FIG. 2, FIG. 3, the outline operation | movement of roll forming which a crack does not generate | occur | produce in the outer side bending surface circular arc B of the high strength steel plate J performed with the 1st roll forming machine 4 and the 2nd roll forming machine 7 is demonstrated. .
First, a flat high-strength steel plate J is formed by an inner bending first upper die 29 and an outer bending first lower die 31 of the first roll die 28 mounted on the first roll forming machine 4 shown in FIG. An inner bending surface arc C2 having the same radius c as the inner bending arc C1 provided at the tip of the first bending upper die 29 and having a range of 2T ≦ c ≦ 4 is added and desired. Roll formed into a high strength steel sheet J having a bending angle α.
Then, by the above-described roll forming, the high strength steel plate J having the range of 2T ≦ c ≦ 4 and having the inner bending surface arc C2 and the bending angle α is mounted on the second roll forming machine 7 shown in FIG. The second roll die 35 is supplied to the outer bending second lower die 38 and the inner bending second upper die 36.
For outward bending of the second roll die 35 in which the plane j2 of the extension j1 extending from the inner bending surface arc C2 of the supplied high strength steel plate J is formed at the same bending angle α as that of the high strength steel plate J. The second lower die 38 is in surface contact with the outer bending plane 38A.
Then, the inner bending arc A1 with the radius a set to a ≦ T provided at the tip of the second inner bending upper die 36 is in contact with the inner bending surface arc C2 of the high-strength steel plate J while rotating. The bending surface arc C2 is pressed in the direction of the intersection 40 (see FIG. 3) of the second lower die 38 for outer bending.
Due to this surface contact and pressing, the material bending and drawing by compression in the center direction of bending of the high strength steel plate J occurs, so that the inner bending surface arc C2 of the high strength steel plate J becomes the inner bending arc A1. Is rolled into an inner bending surface arc A2 having the same radius a.
At the same time, on the outer bending surface of the high tensile strength steel plate J facing the inner bending surface arc A2, an outer bending surface arc B having no radius b = a + T is formed by the above-described roll forming and drawing. The

Next, a detailed operation of roll forming that does not cause a crack in the outer bending surface arc B of the high strength steel plate J performed by the second roll forming machine 7 will be described based on FIGS. 12 to 14.
First, where the above-described roll forming is performed in the second roll mold 35 will be described.
The above-described roll forming and drawing of the high-strength steel sheet J are performed by the contact start (forming start) line TL and the center (shown in the side view of the second roll type roll stand in FIG. End of forming) between lines CL.
Therefore, the second upper die 36 for inner bending and the second lower die 38 for outer bending of the second roll die 35 are rotated in the clockwise direction indicated by the arrow n1 when the second upper die 36 for inner bending rotates. When the second lower mold 38 rotates counterclockwise as indicated by the arrow n2, the loaded high strength steel sheet J is transported between the contact start (formation start) line TL and the center (formation end) line CL. Let it pass.
This contact start (formation start) line TL is inserted into the high strength steel plate inlet 41 shown in FIG. 12 from the direction of arrow N shown in FIG. As a result, the second roll type in which the plane j2 of the extending portion j1 extended from the inner bending surface arc C2 of the high strength steel plate J is formed at the same bending angle α as the supplied high strength steel plate J. The second upper die 36 for inner bending, which is in surface contact with the outer bending flat surface 38A provided on the outer lower bending second die 38, and is formed at the same bending angle α as that of the supplied high tensile strength steel plate J. A line at the time when the inner bending arc A1 provided at the tip of the plate starts to contact the inner bending surface arc C2 of the high tensile strength steel plate J is shown. (State of explanatory drawing (13-I) of FIG. 13)
The center (end of molding) line CL is the center and outer side of the second upper die 36 for inner bending of the second roll die 35 as shown in the side view seen from the roll stand side of the second roll die in FIG. A center line connecting the centers of the second bending lower mold 38 is shown.
The cross-sectional shape of the second roll mold 35 at the center (end of forming) line CL is the second upper mold for inner bending of the second roll mold 35 shown in the front view of the inlet of the high-strength steel sheet of the second roll mold in FIG. 36 and the outer shape of the second lower die 38 for outer bending have a cross-sectional shape.
And the cross-sectional shape in this center (formation completion) line CL roll-forms the high strength steel plate J thrown into the 2nd roll type | mold 35 into the final shape.
That is, since the second upper die 36 for inner bending and the second lower die 38 for outer bending of the second roll die 35 are separated from the center (end of molding) line CL, Drawing is started at the contact start (molding start) line TL shown in FIG. 12, and is terminated at the center (molding end) line CL.

Subsequently, based on FIG. 12 and FIG. 13, between the contact start (molding start) line TL and the center (molding end) line CL shown in the side view seen from the roll stand side of the second roll type in FIG. 12. A description will be given of the fleshing and drawing of the high strength steel plate J performed.
The explanatory diagram (13-I) of FIG. 13 shows the second upper die 36 for inner bending and the second outer bending second die 35 of the second roll die 35 at the contact start (molding start) line TL shown in FIG. The relationship between the lower die 38 and the high tensile strength steel plate J is shown.
That is, when the high strength steel plate J roll-formed by the first roll die 28 is introduced into the high strength steel plate inlet 41 of the second roll die 35 shown in FIG. 12 from the direction of arrow N shown in FIG. The outer side bending of the second roll die 35 formed at the same bending angle α as the plane j2 of the extension j1 extended from the inner bending surface arc C2 of the high strength steel plate J and the supplied high strength steel plate J. Surface contact with the outer bending plane 38A of the second lower mold 38 is made at a contact portion P1 indicated by a bold line.
At the same time, the inner bending arc A1 provided at the tip of the second inner bending upper die 36 formed at the same bending angle α as that of the supplied high strength steel plate J rotates inside the high strength steel plate J while rotating. A relationship is shown in which the bending surface arc C2 comes into contact with the bending surface arc C2 in the direction of the arrow P11, and then starts to be pressed in the direction of the intersection 40 of the second lower bending die 38.
Further, as described above, the second upper mold 36 for inner bending and the second lower mold 38 for outer bending shown in the side view of the second roll mold 35 shown in FIG. The inner bending second upper mold 36 rotates clockwise as indicated by an arrow n1, and the outer bending second lower mold 38 rotates counterclockwise as indicated by an arrow n2.
As a result, the inner bending arc A1 provided at the tip of the inner bending second upper die 36 is in contact with the inner bending surface arc C2 of the high strength steel plate J from the direction of the arrow P11 while rotating, This is a driving force for pressing the inner bending surface arc C2 in the direction of the intersecting portion 40 of the second bending lower mold 38.
Therefore, from the moment when the relationship shown in the explanatory diagram (13-I) shown in FIG. 13 is established, the high tensile strength steel plate J is the explanatory diagram (13-I) of the pressure that presses the high tensile strength steel plate J in the contact portion P1 described above. Is received from the direction of arrow P12 shown in FIG.
And as shown in explanatory drawing (13-I) thru | or explanatory drawing (13-IV), inner side circular arc A1 of the 2nd upper mold | die 36 for inner side bending outside inner side curved surface circular arc C2 of the high tensile strength steel plate J When the second lower die for bending 38 is pressed in the direction of the intersecting portion 40, the tip of the extended portion j1, which is the open end of the high-strength steel plate J, comes into contact with the second upper die for inner bending 36. The contact portion P1 of the contact portion P2 (state of the explanatory view (13-II) of FIG. 13), contact portion P3 (state of the explanatory view of FIG. 13 (13-III)), contact portion P4 (FIG. 13) 13 (state of 13-IV)), the pressure for pressing the high strength steel sheet J generated in the contact portion in the direction of arrow P12 is always generated even if the contact portion changes. .
Thus, between the contact start (formation start) line TL and the center (formation end) line CL shown in the side view seen from the roll stand side of FIG. 12, the high tensile strength steel plate J generated by this contact portion is indicated by an arrow. The pressure pressing in the P12 direction is always generated.
The pressure for pressing the high tensile strength steel plate J in the direction of arrow P12 is such that the inner bending arc A1 provided at the tip of the second inner bending upper die 36 moves the inner bending surface arc C2 of the high strength steel plate J to the arrow P11. By cooperating with the pressure pressing in the direction of the intersecting portion 40 of the second lower bending die 38 from the direction, the pressure pressing the high strength steel sheet J in the direction of the arrow P13 is generated.
The pressure pressed in the direction of the arrow P13 serves to perform so-called fleshing in which the material of the high strength steel plate J is compressed while being compressed toward the center of bending of the high strength steel plate J as indicated by the arrow P14.
Furthermore, since roll forming is performed while the inner bending surface arc C2 of the high tensile strength steel plate J is narrowed to the inner bending surface arc A2 smaller than the radius of the inner bending surface arc C2, the contact portion P2 (description of FIG. 13 (13-II) )), Contact portion P3 (state of explanatory view (13-III) in FIG. 13), contact portion P4 (state of explanatory view (13-IV) in FIG. 13), While forming the inner bending surface arc C2 and the outer bending surface arc S of the tensile strength steel plate J in a straight line, the material of the remaining high tensile strength steel plate J is compressed toward the center of bending of the high strength strength steel plate J as indicated by an arrow P14. However, the work of bringing meat together is also added. (Operation of part X in FIG. 14)
Thus, the high tensile strength steel plate J has an inner bending surface arc A2 in which the inner bending surface arc C2 of the high tensile strength steel plate J has the same radius a as the inner bending arc A1, as shown in the explanatory diagram (13-IV) of FIG. Are formed into rolls. And the state shown to explanatory drawing (13-IV) of FIG. 13 has shown the state of the high strength steel plate J in the position of the center (formation completion) line CL shown in FIG.
These series of operations are functions not found in roll forming that relies solely on the elongation of the high strength steel sheet J shown in FIG. 4, and the bending angle of the high strength steel sheet J to be input and the bending angle of the second roll mold 35 to be input. Are set to the same bending angle α, and the plane j2 of the extension j1 extended from the inner bending surface arc C2 of the high strength steel plate J and the second roll type as shown in the explanatory view (13-I) shown in FIG. The outer bending plane 38A of the second lower die 38 for outer bending 35 is brought into surface contact with a contact portion P1 indicated by a bold line, and the material is brought together and drawn by compression in the center direction of bending of the high strength steel plate J. It is the work that occurs by generating it.
That is, the high tensile strength steel plate J formed and fed at the same bending angle as the first roll die 28 and the second roll die 35 is extended from the inner bending surface arc C2 of the high strength steel plate J. The outer side plane j2 and the outer bending plane 38A of the second lower die 38 for outer bending of the second roll die 35 are in surface contact with each other, and are used for inner bending provided at the tip of the second inner die 36 for inner bending. The arc A1 is sandwiched between the inner bending second upper mold 36 and the outer bending second lower mold 38 by pressing the inner bending surface arc C2.
By this clamping and the inner bending arc A1 pressing the arc, it is possible to suppress the generation of a large bending moment as when pressing the flat plate.
Thereby, the extension which generate | occur | produces on the front side of the high strength steel plate J which inner side arc A1 presses can be suppressed.
As described above, together with the conditions for using the first roll mold 28 and the second roll mold 35 having the same desired predetermined bending angle α, the radius c of the inner bending surface arc C2 of the high strength steel plate J is initially 2T. ≦ c ≦ 4 is roll-formed by the first roll mold 28, and then roll-formed using the second roll mold 35 at a desired bending radius equal to or less than the thickness (plate thickness) T of the high-strength steel plate J By performing two-stage roll forming, the outer bending surface arc B shown in the enlarged view of part M in FIG. 3 is not cracked even at a desired bending radius equal to or less than the thickness (plate thickness) T of the high strength steel plate J. Roll forming is possible.
Thereby, the inner bending surface arc C2 of the high strength steel sheet J is roll-formed into an inner bending surface arc A2 having the same radius a as the inner bending arc A1, and at the same time, the high strength steel sheet facing the inner bending surface arc A2. On the outer bending surface of J, an outer bending surface arc B without a crack having a radius b of b = a + T is formed by pulling and drawing by roll forming described above.

Up to this point, the pulling of the high strength steel sheet J performed between the contact start (forming start) line TL and the center (forming end) line CL shown in the side view of the second roll type roll stand in FIG. The drawing process has been described with reference to the cross-sectional view of FIG. 13 with respective arrows. The three-dimensional view of FIG. 14 shows the three-dimensional directions of the respective arrows.
The high strength steel plate J shown in FIG. 14 is a sample taken out from the process of roll forming with the second roll die 35.
The high strength steel plate J thrown into the second roll mold 35 is conveyed in the direction of arrow Z.
The outer bending surface arc S having the bending angle α is formed by the second roll die 35 between the contact start (molding start) line TL and the center (molding end) line CL (see FIG. 12). The outer bending surface arc B without cracks having the same bending angle α as the outer bending surface arc S is formed by drawing.
From here, the reference numerals shown in FIG. 14 will be described.
The W portion is a portion that is narrowed to the same bending angle α as the outer bending surface arc S as the outer bending surface arc B of the high strength steel plate J is formed.
The X part is a portion where the inner bending surface arc C2 and the outer bending surface arc S of the high tensile strength steel plate J are linearly formed, and the material of the high tensile strength steel plate J that is stretched excessively is pressed toward the Y portion. It is.
The Y portion is a portion where the material of the high strength steel plate J is drawn and drawn.
The contact portion P1 is an extended portion that is extended from the inner bending surface arc C2 of the high-strength steel plate J when the high-strength steel plate J roll-formed by the first roll die 28 is put into the second roll die 35. The plane j2 of j1 and the outer bending plane 38A of the second lower die 38 for outer bending of the second roll die 35 formed at the same bending angle α as that of the supplied high strength steel plate J first come into surface contact. Indicates the position. (See the explanatory diagram (13-I) in FIG. 13)
An arrow P11 indicates a direction in which the inner bending arc A1 provided at the tip of the inner bending second upper die 36 comes into contact with the inner bending surface arc C2 of the high strength steel plate J while rotating.
The arrow P12 indicates that the inner bending arc A1 provided at the tip of the second inner bending upper die 36 contacts the inner bending surface arc C2 of the high tensile strength steel plate J from the direction of the arrow P11 while rotating. The direction of the pressure which presses the high strength steel plate J generated when the inner bending surface arc C2 is pressed in the direction of the intersecting portion 40 of the second lower bending die 38 is shown.
An arrow P13 indicates the direction of pressure generated by pressing the arrows P11 and P12.
An arrow P14 indicates a direction in which meat gathering is performed while compressing the material of the high strength steel plate J.
The contact portion P2 shows the state of the explanatory view (13-II) in FIG. 13, and the arrows P13 and P14 associated with the contact portion P2 are the same as the arrows P13 and P14 associated with the contact portion P1 described above.
The contact part P3 shows the state of the explanatory view (13-III) of FIG. 13, and the arrow P13 and arrow P14 attached to the contact part P3 are the same as the arrow P13 and arrow P14 attached to the contact part P1 described above.
The contact portion P4 shows the state of the explanatory view (13-IV) of FIG. 13, and the high-strength steel plate J that is stretched surplus while forming the inner bending surface arc C2 and the outer bending surface arc S of the high-strength steel plate J linearly. The trace which pressed the material toward Y part is shown.
The functions of these symbols are based on the above-described FIGS. 12 and 13, and the contact start (molding start) line TL and the center (shown from the side view of the second roll type roll stand in FIG. (End of forming) The explanation is made in the portion where the drawing and drawing of the high-strength steel plate J performed between the lines CL are explained, and the explanation here is omitted as reference.

In the roll forming apparatus 1 described above, the high-strength steel plate is obtained only by devising the shapes of the first roll mold 28 mounted on the first roll forming machine 4 and the second roll mold 35 mounted on the second roll forming machine 7. It is not necessary to add an extra device or member to the roll forming apparatus 1 in order to perform roll forming with a desired bending radius equal to or less than the thickness (plate thickness) T of J.
Therefore, the roll forming apparatus can be used as it is only by exchanging the roll mold of the roll forming apparatus used conventionally. This is the same as a normal operation using a roll forming apparatus.
These are that no extra cost is required to perform roll forming at a desired bending radius equal to or less than the thickness (plate thickness) T of the high strength steel plate J.

As described above, according to the first roll mold 28 and the second roll mold 35 according to the first embodiment, the material that is bent through the first roll mold 28 and the second roll mold 35 is as follows. , A high tensile strength steel plate (high-tensile material) J, and its wall thickness (plate thickness) T is regulated to 1.6 mm or less.
This is because, even when the inner bending surface of the high strength steel plate J has the same bending radius, when the wall thickness (plate thickness) T increases, the bending radius of the outer bending surface increases and the elongation of the outer bending surface increases. This is because cracks are likely to occur.
For this crack, the thickness (plate thickness) T of the high tensile strength steel plate J is controlled to 1.6 mm or less, which is practical for reducing the weight, thereby suppressing the influence of the thickness (plate thickness) T. be able to.

Further, in order to roll-form the high-strength steel plate J with a bending radius equal to or less than the wall thickness (plate thickness) T, the first roll mold 28 and the second roll mold 35 used here have a plane of the high-strength steel plate J. A first roll mold 28 having a pair of inner bending first upper mold 29 and outer bending first lower mold 31 to be processed, and a pair of inner bending to process the high strength steel sheet J supplied from the first roll mold 28 The second upper mold 36 and the second roll mold 35 having the outer bending second lower mold 38 are configured.
Then, the first upper die 29 for inner bending and the first lower die 31 for outer bending of the first roll die 28 and the second upper die 36 for inner bending and the second bending die 35 of the second roll die 35 configured as described above are used. The bending angle α for bending the high tensile strength steel plate J of the second lower mold 38 is formed at the same bending angle α.
Further, the inner bending arc C1 for bending the high strength steel plate J formed on the inner bending first upper die 29 of the first roll die 28 has a radius c set to 2T ≦ c ≦ 4, and the second In the inner bending arc A1 for bending the high strength steel plate J formed on the inner bending second upper mold 36 of the roll mold 35, the radius a is set to a ≦ T.

Usually, when a flat plate of the high strength steel plate J is roll-formed by the first upper die 29 for inner bending of the first roll die 28 and the first lower die 31 for outer bending, the high strength steel plate J of the first lower die 31 for outer bending. The two points receiving the fulcrum serve as fulcrums, and the contact point of the inner bending arc C1 provided in the first inner bending die 29 for bending the high strength steel plate J acts as an action point for the high strength steel plate J, and a bending moment is generated.
Due to this bending moment, the front side of the action point that the high strength steel sheet J receives is extended across the action point, and the inner bending arc C1 provided in the first inner bending die 29 that bends the high strength steel sheet J. If roll forming is performed with the radius c set to c ≦ T, the extension of the high-strength steel sheet J cannot follow the front side of the working point, and cracking occurs reliably.
However, by setting the radius c of the inner bending arc C1 for bending the high strength steel plate J to 2T ≦ c and using the high strength steel plate J having a thickness (plate thickness) T of 1.6 mm or less, the first roll In the roll forming of the high strength steel plate J by the mold 28, the elongation of the high strength steel plate J follows the bending moment, so that cracking can be prevented.

Further, the high strength steel plate J is roll-formed by a first roll die 28 in which the radius c of the inner bending arc C1 provided in the first inner bending die 29 for bending the high strength steel plate J is set to c ≦ 4. Thus, the bending angle α provided to the inner bending surface arc C2 formed by the inner bending arc C1 and the first roll mold 28 is given. Then, the high tensile strength steel plate J is put into the second roll mold 35.
In the second roll mold 35, as described above, the bending angle for bending the high strength steel plate J of the second upper mold 36 for inner bending and the second lower mold 38 for outer bending is the same bending angle as that of the first roll mold 28. It is formed with.
Therefore, the high-strength steel plate J formed and fed at the same angle as the first roll die 28 and the second roll die 35 is outside the extended portion j1 extended from the inner bending surface arc C2 of the high-strength steel plate J. Of the second bending die 35 and the outer bending flat surface 38A of the second lower die 38 for outer bending are in surface contact with each other, and the inner bending arc A1 provided at the tip of the inner bending second upper die 36. However, the inner bending surface arc C2 is pressed to be sandwiched between the inner bending second upper mold 36 and the outer bending second lower mold 38.
By this clamping and the inner bending arc A1 pressing the arc, it is possible to suppress the generation of a large bending moment as when pressing the flat plate.
Thereby, the extension which generate | occur | produces on the front side of the high strength steel plate J which inner side arc A1 presses can be suppressed.

Further, an outer plane j2 of the extended portion j1 extending from the inner bending surface arc C2 of the high tensile strength steel plate J and an outer bending plane 38A of the second lower mold 38 for outer bending of the second roll mold 35 are provided. The high-strength steel plate J presses the high-strength steel plate J when the inner-bending arc A1 provided at the front end of the second upper die 36 for inner bending presses the inner-bend surface arc C2. Is received by the side surface in surface contact from the rotating second roll mold 35.
The pressure that presses the high tensile strength steel plate J is such that the inner bending arc A1 provided at the tip of the inner bending second upper die 36 cooperates with the pressure that presses the inner bending surface arc C2. The pressure which presses the steel plate J in the bending center direction is generated, and the pressing pressure works to compress the material of the high tensile strength steel plate J toward the center of bending and perform meat gathering.
Thereby, the inner bending surface arc C2 formed by the first roll mold 28 of the high tensile strength steel plate J is roll-formed into an inner bending surface arc having the same radius a as the inner bending arc A1 in the second roll mold 35, At the same time, on the outer bending surface of the high strength steel sheet J facing the inner bending surface arc, an outer bending surface arc B having a radius b = a + T and having no crack is formed by the above-described roll forming and drawing. Can do it.
Thus, together with the conditions for using the first roll mold 28 and the second roll mold 35 having the same desired bending angle α, the radius c of the inner bending surface arc C2 of the high strength steel plate J is initially 2T ≦ c ≦. 4 is roll-formed by the first roll mold 28 and then the second roll mold 35 is used to roll-form with a desired bending radius a equal to or less than the thickness (plate thickness) T of the high strength steel plate J. Roll forming that does not generate cracks in the outer bending surface arc B even with a desired bending radius of a thickness (plate thickness) T or less with respect to a high tensile strength steel plate J having a small elongation rate by performing two-stage roll forming. Can be made possible.

Next, according to the second roll mold 35, the second roll mold 35 includes the inner bending arc C1 formed on the inner bending first upper mold 29 of the first roll mold 28 and the outer bending first lower mold. A second roll die 35 having an outer bending surface arc S formed on the opposite side of the inner bending surface arc C2 and the inner bending surface arc C2 of the high strength steel plate J formed by the mold 31 is smaller than the radius of the inner bending surface arc C2. The inner bending arc A1 formed on the inner bending second upper die 36 and the outer bending second lower die 38, so that the second bending die upper side of the second rolling die 35 is bent. The inner bending surface arc C2 and the outer bending surface arc S of the high strength steel plate J are formed by a plane continuous from the inner bending arc A1 formed on the mold 36 and a plane formed on the second lower bending mold 38 for outer bending. While forming a straight line as an extension allowance, That than is done meat shifting the lapping while compressing the high tensile strength steel sheet J of the material toward the center bend of high tensile strength steel sheet J.
Thereby, roll forming which does not generate | occur | produce a crack in the outer side bending surface arc B with respect to the high tensile strength steel plate J with small elongation rate, even if it is the desired bending radius below thickness (plate thickness) T can be enabled. .

Next, according to the second roll mold 35, the second roll mold 35 is configured such that the two planes of the inner bending arc A <b> 1 of the inner bending second upper mold 36 and the outer bending second lower mold 38 have a predetermined angle. And a gap D formed by the intersecting portion 40 intersecting at.
According to this, since the bending angle α of the high strength steel plate J that has passed through the first roll die 28 is formed at the same angle as the bending angle α of the second roll die 35, the high strength steel plate J is In the process of inserting into the roll die 35 and roll forming, the outer side bending j2 of the extended portion j1 extending from the inner bending surface arc C2 of the high strength steel plate J and the outer lower bending second die 38 are bent. The second roll die 35 is pressed in the direction of the gap D provided in the center direction of the bending of the high strength steel plate J by sequentially pressing the flat surface 38A while being in surface contact with the second upper die 36 for inner bending. It is possible to easily generate J fleshing and to form the outer bent surface arc B formed by roll forming without cracking.

Next, according to the roll forming apparatus 1, the roll forming apparatus 1 uses the first roll mold 28 and the second roll mold 35 having the same desired bending angle α to start the inner side of the high strength steel plate J. Roll forming is performed by the first roll mold 28 mounted on the first roll forming machine 4 so that the radius c of the bending surface arc C2 is 2T ≦ c ≦ 4, and then the second roll forming machine 7 is mounted. By performing two-stage roll forming using a two-roll die 35 with a desired bending radius a equal to or less than the thickness (plate thickness) T of the high strength steel plate J, the high strength steel plate J having a low elongation rate is obtained. On the other hand, even if it is the desired bending radius below wall thickness (plate thickness) T, roll forming which does not generate | occur | produce a crack in the outer side bending surface circular arc B can be enabled.
In the roll forming apparatus 1, in order to perform roll forming with a desired bending radius equal to or less than the thickness (plate thickness) T of the high tensile strength steel plate J, the first roll mold 28 mounted on the first roll forming machine 4 and To design the shape of the second roll mold 35 mounted on the second roll forming machine 7 and perform roll forming at a desired bending radius a which is equal to or less than the thickness (plate thickness) T of the high strength steel plate J. It is not necessary to add extra devices and members to the roll forming apparatus 1.
Therefore, it can be used as it is as the roll forming apparatus 1 of the present invention simply by replacing the roll mold of the roll forming apparatus used conventionally. Thereby, roll shaping | molding can be performed by the same operation | work as the normal operation | work performed with the conventional roll forming apparatus.
These means that extra labor and cost are not required for roll forming with a desired bending radius a which is equal to or less than the thickness (plate thickness) T of the high tensile strength steel plate J.

  Next, according to the roll forming apparatus 1, the roll forming apparatus 1 is mounted on the second roll forming machine 7 with the second roll mold 35 and is formed on the second upper mold 36 for inner bending of the second roll mold 35. The inner bending surface arc C2 and the outer bending of the high strength steel plate J formed by the first roll die 28 are formed by a plane continuous from the inner bending arc A1 and a plane formed in the second lower bending die 38. By forming the surface arc S in a straight line with the margin of extension, the material of the remaining high tensile strength steel sheet J is compressed toward the center of bending of the high tensile strength steel sheet J, so that the elongation is small. The tensile strength steel plate J can be roll-formed without causing cracks in the outer bending surface arc B even with a desired bending radius of a thickness (plate thickness) T or less.

  Next, according to the roll forming apparatus 1, the roll forming apparatus 1 includes two inner bending arcs A <b> 1 of the inner bending second upper mold 36 and the outer bending second lower mold 38. A bending angle α of the high strength steel sheet J that has the second roll die 35 provided with the gap D formed by the intersecting portion 40 intersecting the plane at a predetermined angle and passed through the first roll die 28 is the second. By forming the roll mold 35 at the same angle as the bending angle α, the high-strength steel sheet J extends from the inner bending surface arc C2 of the high-strength steel sheet J in the process of inserting and rolling the high-strength steel sheet J into the second roll mold 35. The outer bending plane 38A of the outer bending second lower mold 38 and the outer bending plane 38A of the extending extension j1 are sequentially pressed by the inner bending second upper mold 36 while being in surface contact with each other. The 2-roll die 35 is the center of bending of the high strength steel plate J Roll forming can be performed without causing cracks in the outer bending surface arc B formed by roll forming by easily causing the high-strength steel plate J to gather in the direction of the gap D provided in the direction.

And according to the processing method using the roll forming apparatus 1, the first roll forming machine 4 and the second roll forming machine 7 of the roll forming apparatus 1 are used to have the first desired bending angle α. Along with the conditions for using the roll mold 28 and the second roll mold 35, first the first roll of the first roll forming machine 4 so that the radius c of the inner bending surface arc C2 of the high strength steel plate J is 2T ≦ c ≦ 4. Roll forming is performed by the mold 28, and then roll forming is performed by using the second roll mold 35 of the second roll forming machine 7 with a desired bending radius a equal to or less than the thickness (plate thickness) T of the high strength steel plate J 2 This is a processing method in which roll forming in stages is performed.
Therefore, the effect of the roll forming apparatus 1 is taken over as it is, and a high-strength steel sheet J having a small elongation rate is subjected to a two-stage roll forming method even with a desired bending radius of a thickness (plate thickness) T or less. Further, it is possible to provide a roll forming method that does not cause cracks in the outer bending surface arc B.

Next, a second embodiment in which the present invention is applied to a roll forming apparatus will be described in detail with reference to the drawings.
In the second embodiment, a roll mold, a roll forming machine, and a high-strength steel sheet having a wall thickness (plate thickness) T of 1.6 mm or less without causing cracking, a roll forming machine, and The roll forming apparatus will be described. In addition, the code | symbol shall suppose that what has the same function as 1st Embodiment uses the same code | symbol.
First, a schematic configuration of the roll forming apparatus 101 according to the second embodiment will be described with reference to FIG.
Here, FIG. 15 is a top view of the roll forming apparatus according to the second embodiment.
As shown in FIG. 15, the roll forming apparatus 101 includes a first roll forming machine 4 connected to the first speed reducer 3 via the first rotary connecting machine 2 and a second rotary connecting machine 5. The second roll forming machine 7 connected to the second speed reducer 6, the third roll forming machine 110 connected to the third speed reducer 109 via the third rotary connecting machine 108, and the fourth rotary connecting machine. A fourth roll forming machine 113 connected to the fourth speed reducer 112 via 111 and a fifth roll forming machine 116 attached to the fourth roll forming machine 113 are disposed on the base 17.
The first speed reducer 3 and the second speed reducer 6 are connected by a sixth rotary coupler 18, the second speed reducer 6 and the third speed reducer 108 are connected by a seventh rotary coupler 119, and the third The speed reducer 108 and the fourth speed reducer 112 are connected by an eighth rotary coupler 120, and the first speed reducer 31 is connected to the motor 23 by a tenth rotary coupler 122, and the first roll forming machines 4 to 4 are connected. The fourth roll forming machine 113 is put into a state where it can be operated.
Further, the roll forming apparatus 101 is provided with an auxiliary equipment 124 for supplying a raw material to be roll-formed as an auxiliary equipment and a next process equipment 125 for performing drilling, cutting, bending, etc., and continuously manufactures one part. It has a configuration.

Next, the configuration and functions of the first roll forming machine 4 to the fifth roll forming machine 116 will be described with reference to FIGS. 15, 2, 3, and 16 to 18.
Here, FIG. 16 is a side view seen from the side of the third roll mold of the third roll molding machine, FIG. 17 is a side view seen from the side of the fourth roll mold of the fourth roll molding machine, and FIG. FIG. 10 is a side view of the fifth roll forming machine as viewed from the side of the fifth roll mold.
First, the configuration and function of the first roll forming machine 4 shown in FIGS. 15 and 2 will be described. The first roll forming machine 4 uses the first roll forming machine 4 of the first embodiment as it is. Therefore, here, the description and the description thereof will be omitted by referring to the configuration and function of the first roll forming machine 4 of the first embodiment.
Similarly, the configuration and function of the second roll forming machine 7 shown in FIGS. 15 and 3 will be described. The second roll forming machine 7 uses the second roll forming machine 7 of the first embodiment as it is. Therefore, here, the configuration and function of the second roll forming machine 7 of the first embodiment will be referred to and the description thereof will be omitted.

Then, the structure and function of the 3rd roll forming machine 110 arrange | positioned in the downstream of the 2nd roll forming machine 7 are demonstrated based on FIG. 15, FIG.
As shown in FIGS. 15 and 16, the third roll forming machine 110 includes a third roll stand R142 and a third roll stand L143 that are erected from the base 17.
The third roll stand R142 and the third roll stand L143 include a third shaft upper body 146 to which one inner bending third upper mold 145 constituting the third roll mold 144 is attached, and the other outer bending first. A third lower shaft body 148 to which a three lower mold 147 is attached is mounted.
The upper third shaft body 146 and the lower third shaft body 148 are provided with a desired gap in the third upper mold 145 for inner bending and the third lower mold 147 for outer bending, and the third roll stand R142 and the third roll. It is fixed so as to be rotatable with respect to the stand L143.
The third roll forming machine 110 configured as described above is in an operable state when the third shaft body lower part 148 is connected to the third rotary connecting machine 108.
Then, the 3rd roll type | mold 144 attached to the 3rd roll forming machine 110 is demonstrated based on FIG.
As described above, the third roll mold 144 includes the inner bending third upper mold 145 and the outer bending third lower mold 147.
The high-strength steel plate J having a thickness (plate thickness) T of 1.6 mm or less supplied from the second roll forming machine 7 on the upstream side is subjected to the inner bending surface arc A2 and the outer bending surface arc by the second roll die 35. B and a bending angle α are given.
Then, as shown in the enlarged view of the q part corresponding to the final step of the roll forming performed in the third roll mold 144 of FIG. 16, the third roll mold 144 is a bending without cracking from the bending angle α to the bending angle β. This is a roll mold for forming the high strength steel sheet J.
In order to form the third roll mold 144, first, the inner bending third upper mold 145 shown in the enlarged view of the portion Q in FIG. The inner bending arc A1 formed on the inner bending second upper die 36 of the second roll die 35 is set to have the same range and radius a (e = a, E = A1).
Thus, the inner bending arc E serves as a positioning and holding portion for the inner bending surface arc A2 attached to the high tensile strength steel plate J to which the inner bending arc E is supplied. The external pressure is not applied again to the inner bending surface arc A2 and the outer bending surface arc B once formed.
That is, since the inner bending surface arc A2 and the outer bending surface arc B of the high strength steel plate J are positioned and held on the inner bending arc E, the inner bending surface arc A2 and the outer bending surface arc B are not affected by external pressure. The bending stress concentrated on the apex of the outer bending surface arc B of the tensile strength steel plate J can be eliminated.
Then, as shown in the enlarged view of the Q part in FIG. 16, the third upper die 145 for inner bending is used for inner bending of the third upper die 145 for inner bending as a place where new external pressure is applied to the high tensile strength steel plate J. An inner bending arc F1 having a radius f extending from the both ends of the arc E with the relationship of inner bending arc E <inner bending arc F1 is provided, and the bending angle β for bending the high-strength steel plate J is the inner bending arc F1. To be tangent to.
The operation of the third roll mold 144 is performed by driving the motor 23 so that the inner bending third upper mold 145 provided with the inner bending arc F1 cooperates with the outer bending third lower mold 147, Bending the high-strength steel plate J without cracking while forming the two inner bending surface arcs F2 from both ends of the inner bending surface arc A2 of the high-strength steel plate J supplied from the upstream side without applying external pressure to the inner bending surface arc A2. Roll forming is performed at an angle β.

Next, the configuration and function of the fourth roll forming machine 113 arranged on the downstream side of the third roll forming machine 110 will be described with reference to FIGS. 15 and 17.
As shown in FIGS. 15 and 17, the fourth roll forming machine 113 includes a fourth roll stand R149 and a fourth roll stand L150 that are erected from the base 17.
The fourth roll stand R149 and the fourth roll stand L150 have a fourth shaft upper part 153 to which one inner bending fourth upper mold 152 constituting the fourth roll mold 151 is attached, and a fourth roll mold 151. A fourth shaft lower body 155 to which the other outer bending fourth lower mold 154 is mounted is mounted.
The fourth shaft body 153 and the fourth shaft body lower 155 are provided with a desired gap in the inner bending fourth upper mold 152 and the outer bending fourth lower mold 154, and the fourth roll stand R149 and the fourth roll. It is rotatably fixed to the stand L150.
The fourth roll forming machine 113 configured as described above is in an operable state when the lower fourth shaft body 155 is connected to the fourth rotary connecting machine 111.
Then, the 4th roll type | mold 151 attached to the 4th roll forming machine 113 is demonstrated based on FIG.
As described above, the fourth roll mold 151 includes the inner bending fourth upper mold 152 and the outer bending fourth lower mold 154.
The inner roll surface arc A2 was left by the third roll mold 144 in the high strength steel plate J having a wall thickness (plate thickness) T of 1.6 mm or less supplied from the third roll forming machine 110 on the upstream side. In the state, the inner bending surface arc F2 and the bending angle β are formed continuously to the inner bending surface arc A2.
The fourth roll mold 151 performs fleshing and squeezing while pressing the material of the inner bending surface arc F2 formed continuously to the remaining inner bending surface arc A2 toward the inner bending surface arc A2, Roll forming into an integral semicircular arc including the inner bending surface arc A2 with the same radius as the inner bending surface arc A2.
That is, as shown in the enlarged view of the portion r corresponding to the final process of roll forming performed in the fourth roll mold 151 in FIG. 17, the fourth roll mold 151 has the same inner bending surface arc F2 as the inner bending surface arc A2. This is a roll die that is formed into an integral semicircular arc including an inner bending surface arc A2 with a radius and roll-forms without causing cracks in a U-shape with parallel faces of the high-strength steel plate J facing each other.
For this purpose, as shown in the enlarged view of the R part in FIG. 17, the outer bending fourth lower mold 154 includes an outer bending semicircular arc G1 set to a semicircular arc having a radius g = a + T, and an outer side. Parallel bending outer wall surfaces 154A extending from both ends of the bending semicircular arc G1 are provided.
That is, the outer bending semicircular arc G1 is a semicircular arc including the outer bending surface arc B facing the inner bending surface arc A2.
The operation of the fourth roll mold 151 is as follows. First, the outer bending wall surface 154A and the outer bending semicircular arc G1 of the outer bending fourth lower mold 154 are driven by the motor 23 to move the fourth bending upper mold. The outer bending surface arc B of the high strength steel sheet J that is press-fitted into the outer bending wall surfaces 154A parallel to each other by the pressing of 152 is held.
At the same time, the two inner bending surface arcs F2 provided on the held high tensile strength steel plate J are compressed and pressed by the inner bending fourth upper mold 152 and have the same radius g as the outer bending semicircular arc G1. Roll forming is performed on a U-shaped high tensile strength steel plate J having no outer bent surface semicircular arc G2 and having no cracks.
At this time, an inner bending surface semicircular arc G3 having a radius a is formed inside the U-shaped high strength steel plate J.
The fourth upper die 152 for inner bending of the fourth roll die 151 may be extended to form an inner bending semicircular arc having a radius a at the tip thereof to serve as a positioning and holding portion for the inner bending surface arc A2.

Next, the configuration and function of the fifth roll forming machine 116 disposed on the downstream side of the fourth roll forming machine 111 will be described with reference to FIGS. 15 and 18.
As shown in FIGS. 15 and 18, the fifth roll forming machine 116 is attached to a support base 156, a fifth shaft body L 157 and a fifth shaft body R 158 erected from the support base 156, and a fifth shaft body L 157. One press roll mold L160 constituting the fifth roll mold 159, the other press roll mold R161 constituting the fifth roll mold 159 attached to the fifth shaft body R158, the fifth shaft body L157 and the It is comprised with the connection fixing plate 162 which connects and fixes the upper end of 5-shaft body R158.
Then, the fifth roll forming machine 116 configured as described above is attached to the fourth roll stand R149 and the fourth roll stand L150 standing from the base 17 by the support base 156 of the fifth roll forming machine 116. Yes.
Next, the fifth roll mold 159 attached to the fifth roll forming machine 116 will be described with reference to FIGS. 15 and 18.
As described above, the fifth roll mold 159 includes the press roll mold L160 and the press roll mold R161.
A high strength steel plate J having a wall thickness (plate thickness) T of 1.6 mm or less supplied from the fourth roll forming machine 111 on the upstream side is formed in a U shape having an outer curved surface semicircular arc G2 having a radius g. However, the fifth roll mold 159 applies pressure from the side to the U-shaped high strength steel plate J while the press roll mold L160 and the press roll mold R161 rotate, and the outer bent surface The final step of the so-called hemming bending (180 ° bending bending process) while compressing and bringing the semi-circular arc G2 and the inner bending surface semicircular arc G3 into the center of bending of the high-strength steel plate J as the extension allowance. It is a roll type that performs.
Therefore, the pressing roll mold L160 and the pressing roll mold R161 each have a cylindrical surface and are arranged in parallel so that the cylindrical surface becomes a 2T gap.
The fifth roll mold 159 is driven by the first roll forming machine 4 to the fourth roll forming machine 113 carrying the high strength steel plate J and press-fitting it into the fifth roll mold 159.
As a result, the U-shaped high strength steel plate J having a thickness (plate thickness) T supplied from the upstream side passes through the fifth roll mold having cylindrical surfaces arranged in parallel with a 2T gap. Even in the final processing of the hemming bending to be pressed, sufficient gathering by the first roll forming machine 4 and the second roll forming machine 7, protection of the bent portion by the third roll forming machine 110, and the fourth roll forming machine Due to the pre-process of 111 pressing and fleshing, and the characteristic of flickering called roll forming of the fifth roll forming machine 116, cracking occurs on the outer bending surface semicircular arc G2 to which the final processing of hemming bending is applied. Hemming-bending roll forming is performed without causing any problems.
That is, hemming-bending roll forming without cracking can be performed on the outer bending surface arc B included in the outer bending surface semicircular arc G2.

For the roll forming apparatus 101 having such a configuration and function, the thickness (plate thickness) T of the high tensile strength steel plate J used in the present invention is 1.6 mm or less, and the thickness (plate thickness) is empirically. The thicker the plate, the easier it is to break, so we used a high tensile strength steel plate J with a wall thickness (plate thickness) of 1.6 mm and introduced four types of samples with tensile strengths of 980 MPa (megapascal), 1180 MPa, 1270 MPa and 1470 MPa, respectively. A confirmation test of hemming bending was conducted.
The result is shown in FIG.
Here, FIG. 19 is an explanatory view for explaining the result of hemming when the plate thickness T = 1.6 mm.
As shown in FIG. 19, hemming bending without cracking can be performed in any sample of the high tensile strength steel sheet J having a small elongation rate.
Thereby, according to the structure and function with which the 1st roll forming machine 4 thru | or the 5th roll forming machine 116 are provided also with respect to the high strength steel plate J with a small elongation rate, as above-mentioned, with the 1st roll forming machine 4 Sufficient meat gathering by the second roll molding machine 7, protection of the bent portion by the third roll molding machine 110, pre-process of pressing and meat gathering by the fourth roll molding machine 111, and fifth roll molding machine of the final process It was confirmed that the hemming bending process can be performed due to the flesh-rolling characteristic of 116 roll forming.

As described above, according to the roll forming apparatus 101 according to the second embodiment, the inside bending of the high strength steel plate J that is roll-formed by the second roll forming machine 7 so that the predetermined angle and the radius a are a ≦ T. The surface arc A <b> 2 is used for a hemming bend performed by a roll forming machine downstream of the second roll forming machine 7 to perform hemming bend roll forming.
The inner bending surface arc A2 of the high strength steel sheet J roll-formed by the second roll forming machine 7 so that the predetermined angle and the radius a are a ≦ T is the bending of the high strength steel sheet J to be input to the second roll forming machine 7. The second roll mold 35 and the second roll mold 35 are set to have the same bending angle α, the plane j2 outside the extended portion j1 extending from the inner bending surface arc C2 of the high strength steel plate J, and the second roll mold The outer bending plane 38A of the second lower die 38 for outer bending 35 is brought into surface contact with the material, and the material is brought together and drawn by compression toward the center of bending of the high strength steel plate J, and the high strength steel plate J In the contact portions P1 to P4, the inner bending surface arc C2 of the high strength steel plate J and the outer bending are bent at the contact portions P1 to P4. Form the surface arc S in a straight line And while, also acts joined sufficient meat gathering performing meat shifting the lapping while compressing against the material of the high tensile strength steel sheet J intolerable extending the center bend of high tensile strength steel sheet J is performed.
By using the inner bending surface arc A <b> 2 of the high strength steel plate J formed in this way as a bending portion for hemming bending, it is possible to perform hemming bending roll forming without cracking.

  Next, according to the roll forming apparatus 101, the inner bending surface arc A <b> 2 roll-formed by the second roll forming machine 7 so that the radius a is a ≦ T is the third roll mold mounted on the third roll forming machine 110. The external force applied to the inner bending surface arc A2 is positioned and held on the inner bending arc E of 144, and is positioned and held on the outer bending semicircular arc G1 of the fourth roll mold 151 mounted on the fourth roll forming machine 113. By eliminating, even if it puts into the last process of hemming bending performed with the 5th roll forming machine 116, roll forming of hemming bending without a crack can be performed.

Next, according to the roll forming apparatus 101, in the third roll forming machine 110, an external force is applied to the inner bending surface arc A2 formed by the second roll forming machine 7 with respect to the high strength steel plate J supplied from the upstream side. In order to perform bending from the bending angle α by the second roll die 35 to the next bending angle β, the inner bending surface arc A2 formed by the second roll forming machine 7 is used for inner bending of the third roll die 144. The second roll forming machine 7 is held by an inner bending arc F1 having a radius f and held in the arc E and provided in the third roll mold 144 and has a relationship of (inner bending arc A1) <(inner bending arc F1). And two inner bending surface arcs F2 extending from both ends of the inner bending surface arc A2 roll-formed with a radius a ≦ T, and the next bending angle β extends from the inner bending surface arc A2. Inner curved surface arc And to the roll forming so that the two angles formed by the extending portion j3 provided in the same position as the tangent of the second tip portion F3.
Thus, in order to bend from the bending angle α by the second roll die 35 to the next bending angle β, the inner bending surface arc A2 is held on the inner bending arc E of the third roll die 144, and the inner bending surface arc A2 is held. The inner bending surface arc A2 can be protected from an external force for bending to the next bending angle β by providing a bending portion at a different location instead of bending.

Next, according to the roll forming apparatus 101, in the fourth roll forming machine 113, the high strength steel sheet J supplied from the upstream side is subjected to an external force on the inner bending surface arc A2 remaining in the third roll forming machine 110. In order to form a U-shape with the fourth roll mold 151 without any change, the inner bending surface arc A2 is held by the outer bending semicircular arc G1 of the fourth roll mold 151 and is formed by the third roll forming machine 110. The two inner bending surface arcs F2 are roll-formed into an arc having the same radius a (a ≦ T) as the inner bending surface arc A2, and are formed into a U shape with a semicircular arc having the radius a. .
When the inner bending surface arc F2 is roll-formed by the fourth roll die 151 into an arc having the same radius a (a ≦ T) as the inner bending surface arc A2, the material of the inner bending surface arc F2 is the rotating fourth material. The roll die 151 is squeezed while being pressed toward the existing inner bending surface arc A2 held by the outer bending semicircular arc G1 of the fourth roll die 151, and formed into the same radius a as the inner bending surface arc A2. Therefore, it can overcome the extending force of the material and prevent cracking.
In this way, a semicircular arc having a radius a can be formed while protecting the existing inner bending surface arc A2.

Next, according to the roll forming apparatus 101, the fifth roll forming machine 116 of the fifth roll forming machine 116 in which the high strength steel plate J formed in a U shape by the fourth roll mold 151 of the fourth roll forming machine 113 is arranged on the downstream side. When it is put into the 5-roll mold 159, the press roll mold L160 having the pair of cylindrical surfaces of the fifth roll mold 159 and the press roll mold LR161 are rotated while the U-shaped high strength steel plate J is rotated. The pressure is applied sequentially from the side, and the inner bending surface semicircular arc G3 having a radius a (a ≦ T) and the inner bending surface semicircular arc G2 having a radius (a + T) are extended to perform hemming bending roll forming. I made it.
The direction of the center of bending of the high strength steel sheet J by the rotation of the pressure roll mold L160 having the pair of cylindrical surfaces of the fifth roll mold 159 and the rotation of the pressure roll mold LR161 and the pressing of the high strength steel sheet J sequentially from the side surface. Therefore, hemming bending roll forming can be performed without causing cracks in the hemming bending portion.

Next, according to the processing method using the roll forming apparatus 101, the first roll forming machine 4 and the second roll forming machine 7 of the roll forming apparatus 101 are used to have the first desired bending angle α. Along with the conditions for using the roll mold 28 and the second roll mold 35, first the first roll of the first roll forming machine 4 so that the radius c of the inner bending surface arc C2 of the high strength steel plate J is 2T ≦ c ≦ 4. By roll forming with the mold 28, and then using the second roll mold 35 of the second roll forming machine 7 with a desired bending radius a (a ≦ T) equal to or less than the thickness (plate thickness) T of the high strength steel plate J The inner bending surface arc A2 formed by the two-stage roll forming that performs the roll forming is used for a hemming bend performed by the roll forming machine on the downstream side of the second roll forming machine 7. In the processing method that performs That.
In this way, the roll forming apparatus 101 has a hemming-bending bent portion of the inner bending surface arc A2 that is sufficiently brought close to the bending portion of the arc by the first roll forming machine 4 and the second roll forming machine 7 of the roll forming apparatus 101. By using this method, it is possible to provide a processing method for performing roll forming of hemming bending that does not generate cracks in the bending portion of hemming bending.

  And according to the processing method using the roll forming apparatus 101, it is said that the inner bending surface arc A2 roll-formed by the second roll forming machine 7 so that the radius a is a ≦ T is used for the bending portion of the hemming bending. As a result, it is positioned and held on the inner bending arc E of the third roll mold 144 mounted on the third roll molding machine 110, and is also mounted on the fourth roll molding machine 113 and the outer bending half of the fourth roll mold 151. By the method of eliminating the external force applied to the inner bending surface arc A2 while being positioned and held by the circular arc G1, roll forming of hemming bending without cracking is performed even if it is put into the final step of hemming bending performed by the fifth roll forming machine 116. A processing method to be performed can be provided.

  In addition, this invention is not limited to such embodiment at all, and can be implemented with various aspects in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Roll forming apparatus 4 1st roll forming machine 7 2nd roll forming machine 23 Motor 28 1st roll type | mold 29 1st upper type | mold for inner side bending 31 1st lower type | mold for outer side bending 35 2nd roll type | mold 36 2nd for inner side bending Upper die 38 Second lower die 40 for bending outside 101 Intersection 101 Roll forming device 110 Third roll forming machine 113 Fourth roll forming machine 116 Fifth roll forming machine 144 Third roll die 151 Fourth roll die 159 Fifth roll die 160 Press roll type L
161 Press roll type R
A1 Arc for inner bending A2 Arc for inner bending surface a Radius B Arcing for outer bending surface b Radius C1 Arc for inner bending C2 Inner bending surface arc c Radius D Clearance E Arc for inner bending F1 Arc for inner bending F2 Inner bending arc F radius G1 Semicircular arc for outer bending G3 Inner bending surface semicircular arc J High strength steel sheet S Outer bending arc T Thickness (thickness)
α Bending angle β Bending angle

Claims (14)

A roll mold that is mounted on a roll forming apparatus and roll-forms a high-strength steel sheet having a thickness T of 1.6 mm or less,
A first roll mold having an inner bending first upper mold and an outer bending first lower mold for roll-forming the high strength steel sheet;
A second roll mold having a second upper mold for inner bending and a second lower mold for outer bending for roll-forming the high-strength steel sheet supplied from the first roll mold;
With
On the roll forming surfaces of the first upper die for inner bending and the first lower die for outer bending of the first roll die, and the second upper die for inner bending and the second lower die for outer bending of the second roll die. The bending angle for bending the formed high strength steel sheet is formed at the same angle,
The radius c of the inner bending arc C1 formed on the first upper mold for inner bending of the first roll mold is set to 2T ≦ c ≦ 4 mm,
The radius a of the inner bending arc A1 in the second inner bending upper mold is set to a ≦ T ,
When roll forming the high strength steel sheet supplied from the first roll mold with the second roll mold, a surface contact portion between the outer bending surface of the high strength steel sheet and the outer bending surface of the second lower mold and the inner side A roll mold characterized by suppressing a bending moment generated by pressing the inner bending arc A1 in the second bending upper mold.   The inner bending surface arc C2 and the inner bending of the high strength steel plate formed by the inner bending arc C1 and the outer bending first lower mold formed in the first upper bending inner upper mold of the first roll mold. The outer bending surface arc S formed on the opposite side of the surface arc C2 includes the inner bending arc A1 and the outer bending second lower mold formed in the second upper mold for inner bending of the second roll mold. The roll mold according to claim 1, wherein an extension allowance is generated when roll forming is performed.   When roll forming is performed via the second roll mold, there is a gap D between the outer bending surface arc B formed on the outer side of the high tensile strength steel sheet and the corner of the second lower mold for outer bending. The roll mold according to claim 1, wherein the roll mold is formed. A roll forming apparatus for roll forming a high strength steel sheet having a thickness T of 1.6 mm or less,
A first roll forming machine equipped with a first roll mold having a first upper mold for inner bending and a first lower mold for outer bending for roll-forming the high tensile strength steel sheet;
A second roll forming machine equipped with a second roll mold having a second upper mold for inner bending and a second lower mold for outer bending for roll-forming the high-strength steel sheet supplied from the first roll mold;
With
On the roll forming surfaces of the first upper die for inner bending and the first lower die for outer bending of the first roll die, and the second upper die for inner bending and the second lower die for outer bending of the second roll die. The bending angle for bending the formed high strength steel sheet is formed at the same angle,
The radius c of the inner bending arc C1 formed on the first upper mold for inner bending of the first roll mold is set to 2T ≦ c ≦ 4 mm,
The radius a of the inner bending arc A1 in the second inner bending upper mold is set to a ≦ T ,
When roll forming the high strength steel sheet supplied from the first roll mold with the second roll mold, a surface contact portion between the outer bending surface of the high strength steel sheet and the outer bending surface of the second lower mold and the inner side A roll forming apparatus characterized by suppressing a bending moment generated by pressing an inner bending arc A1 in a second upper mold for bending .   The high tensile strength formed by the inner bending arc C1 and the outer bending first lower mold formed in the first bending inner upper mold of the first roll mold mounted on the first roll forming machine. An outer bending surface arc S formed on the opposite side of the inner bending surface arc C2 and the inner bending surface arc C2 of the steel sheet is a second upper mold for inner bending of the second roll mold mounted on the second roll forming machine. 5. The roll forming apparatus according to claim 4, wherein an extension allowance is generated when roll forming is performed by the inner bending arc A <b> 1 and the second outer bending second mold.   When roll forming is performed via the second roll mold mounted on the second roll forming machine, an outer bending surface arc B formed on the outer side of the high strength steel sheet and the second lower mold for outer bending. The roll forming apparatus according to claim 4 or 5, wherein a gap D is formed between the corners.   The inner bending surface arc A2 of the high strength steel sheet roll-formed so as to have a radius a ≦ T through the inner bending arc A1 in the second inner bending upper die of the second roll forming machine, The roll forming of hemming bending is performed by using the bending portion of the hemming bending performed by the roll forming machine on the downstream side of the two-roll forming machine. Roll forming equipment. The second roll forming machine is arranged on the downstream side of the second roll forming machine and bend-formed from the bending angle of the second roll mold to a smaller bending angle from the high-strength steel plate having the thickness T supplied from the upstream side, and the second roll A third roll forming machine equipped with a third roll mold provided with a holding part for positioning and holding the inner curved surface arc A2 roll-formed with a forming machine so that the radius a ≦ T;
The high strength steel sheet disposed on the downstream side of the third roll forming machine and supplied from the upstream side leaving the inner bending surface arc A2 is formed into a U shape, and the inner bending surface arc A2 is positioned and held. A fourth roll forming machine for mounting a fourth roll mold provided with a holding part;
A fifth roll mold comprising a press roll mold having a pair of cylindrical surfaces arranged in parallel with a 2T gap provided at the downstream side of the fourth roll forming machine is provided from the upstream side. A fifth roll forming machine for pressing the inner bent surface arc A2 left on the high tensile strength steel plate having a thickness T with a pair of pressing roll dies,
With
The inner bending surface arc A2 roll-formed by the second roll forming machine so that the radius is a ≦ T is positioned and held by the holding part of the third roll type, and the holding part of the fourth roll type The external force applied to the inner bending surface arc A2 by being positioned and held is eliminated, and used in a bending portion of hemming bending performed in the fifth roll forming machine. The roll forming apparatus as described.   In the third roll forming machine, the inner bending surface arc A2 formed by the second roll forming machine is held by the holding portion of the third roll mold, and the inner bending arc A1 provided in the third roll mold. <Inner bending arc F1 having a relationship of inner bending arc F1 and extending from both ends of inner bending surface arc A2 roll-formed by the second roll forming machine so that the radius becomes a ≦ T. The two extending portions provided at the same position as the tangent of the tip of the inner bending surface arc F2 extending from the inner bending surface arc A2 are formed while forming the two inner bending surface arcs F2 to be projected. The roll forming apparatus according to claim 8, wherein the roll forming is performed so as to have an angle formed.   In the fourth roll forming machine, the inner bending surface arc A2 or the outer bending surface arc B is held by the holding portion of the fourth roll mold, and two inner bending surfaces formed by the third roll forming machine. The arc F2 is roll-formed into an arc of radius a which is the same as the inner bending surface arc A2 and a ≦ T, and is formed into a U shape having a semicircular arc of radius a. Item 10. The roll forming apparatus according to item 8 or 9.   When the high strength steel sheet formed in a U shape by the fourth roll mold of the fourth roll molding machine is put into the fifth roll mold of the fifth roll molding machine arranged on the downstream side, the fifth roll mold A press roll mold having a pair of cylindrical surfaces is rotated sequentially from the side to a U-shaped high strength steel plate while rotating, and a semicircular arc having a radius of a ≦ T is extended. The roll forming apparatus according to claim 8, wherein roll forming is performed by hemming bending. A processing method of bending a high strength steel plate having a plate thickness T of 1.6 mm or less by roll forming at a radius of the plate thickness T or less,
A first roll forming machine equipped with a first roll mold having a first upper mold for inner bending and a first lower mold for outer bending for roll-forming the high tensile strength steel sheet;
A second roll forming machine equipped with a second roll mold having a second upper mold for inner bending and a second lower mold for outer bending for roll-forming the high-strength steel sheet supplied from the first roll mold;
With
On the roll forming surfaces of the first upper die for inner bending and the first lower die for outer bending of the first roll die, and the second upper die for inner bending and the second lower die for outer bending of the second roll die. The bending angle for bending the formed high strength steel sheet is formed at the same angle,
The radius c of the inner bending arc C1 formed on the first upper mold for inner bending of the first roll mold is set to 2T ≦ c ≦ 4 mm,
While bending by roll forming by the following radii said high tensile strength steel plate thickness T by a roll molding apparatus radius a of the inner bend for arc A1 set in a ≦ T in the second upper-die said inner bend,
When roll forming the high strength steel sheet supplied from the first roll mold with the second roll mold, a surface contact portion between the outer bending surface of the high strength steel sheet and the outer bending surface of the second lower mold and the inner side The processing method characterized by suppressing the bending moment which generate | occur | produces by the press of the inner side bending arc A1 part in the 2nd upper mold for bending .   The inner bending surface arc A2 of the high strength steel sheet roll-formed so as to have a radius a ≦ T through the inner bending arc A1 in the second inner bending upper die of the second roll forming machine, 13. The processing method according to claim 12, wherein a roll forming process for hemming bending is performed using a bending part for hemming bending performed by a roll forming machine downstream of the two-roll forming machine. The second roll forming machine is arranged on the downstream side of the second roll forming machine and bend-formed from the bending angle of the second roll mold to a smaller bending angle from the high-strength steel plate having the thickness T supplied from the upstream side, and the second roll A third roll forming machine equipped with a third roll mold provided with a holding part for positioning and holding the inner curved surface arc A2 roll-formed with a forming machine so that the radius a ≦ T;
The high strength steel sheet disposed on the downstream side of the third roll forming machine and supplied from the upstream side leaving the inner bending surface arc A2 is formed into a U shape, and the inner bending surface arc A2 is positioned and held. A fourth roll forming machine for mounting a fourth roll mold provided with a holding part;
A fifth roll mold comprising a press roll mold having a pair of cylindrical surfaces arranged in parallel with a 2T gap provided at the downstream side of the fourth roll forming machine is provided from the upstream side. A fifth roll forming machine for pressing the inner bent surface arc A2 left on the high tensile strength steel plate having a thickness T with a pair of pressing roll dies,
With
The inner bending surface arc A2 roll-formed by the second roll forming machine so that the radius is a ≦ T is positioned and held by the holding part of the third roll type, and the holding part of the fourth roll type Hemming bending is applied to the high strength steel sheet by a roll forming apparatus that is used for a bending portion of hemming bending performed in the fifth roll forming machine. The processing method according to claim 12 or 13, wherein the roll forming process is performed.

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