JP5589461B2 - Press roll forming apparatus and press roll forming method - Google Patents

Description

  The present invention relates to a press roll forming apparatus and a press roll forming method.

2. Description of the Related Art Conventionally, a press roll forming apparatus that forms a material piece by pressing the roll against the material piece placed on a square or circular mold and moving the material piece has been widely used.
For example, most of the stationary blades used in a compressor of a jet engine are a kind of press roll forming apparatus and manufactured by a press roll forging apparatus that performs forging simultaneously with forming (Patent Documents 1 and 2).

  For example, in the press roll forging device disclosed in Patent Documents 1 and 2, a hydraulic device or the like that applies a load to the roll is movable together with the roll, and is gripped and supported on the front side of the mold. The material piece is formed by pressing the material piece against the mold as the roll moves.

U.S. Pat. No. 4,483,168 US Pat. No. 5,600,995

By the way, for example, a part to be gripped when molding a piece of material is not molded by a mold, and therefore cannot be used as a part of a part. That is, in a single piece of material, a part used as a product is a part.
For this reason, conventionally, only a necessary part is cut out from the material piece formed by the press roll forging device. And the site | part used for the other components including the site | part by which the piece of material is hold | gripped will be discarded after a required site | part is cut out.
In other words, in the conventional press roll forging device, a part of the material piece required for the part is a part and the other part is discarded, so that the material is wasted.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce the material discarded by reducing the size of a material piece in a press roll forming apparatus and a press roll forming method.

  The present invention adopts the following configuration as means for solving the above-described problems.

  1st invention is a press roll molding apparatus which comprises a metal mold | die and shape | molds the said material piece by pressing a material piece with respect to the said metal mold | die with a roll, Comprising: The material mounted on the said metal mold | die A configuration is adopted in which a pressing mechanism is provided that presses the roll against the material piece with any position on the piece as a load start point.

  According to a second invention, in the first invention, a configuration is adopted in which a mold rotation mechanism for rotating the mold with respect to the roll is provided.

  3rd invention has the said some metal mold | die used with respect to the said single material piece in the said 1st or 2nd invention, The order of the depth of the shaping | molding groove part of the said metal mold | die being used. Adopting a structure that becomes shallower.

  According to a fourth invention, in any one of the first to third inventions, the mold is formed on a main groove portion for forming the material piece into a target shape and on the outside of the main groove portion. A configuration is provided that includes a position restricting portion that restricts the position.

  A fifth invention is a press roll molding method for forming the material piece by pressing the material piece against the mold with a roll, the material piece being placed on the mold, and the mold A configuration is adopted in which the roll is pressed against the material piece with any position on the material piece placed thereon as a load start point.

  6th invention employ | adopts the structure which presses and moves the said roll from several different directions with respect to the said material piece in the said 5th invention.

  According to a seventh invention, in the fifth or sixth invention, a single piece of material is formed using a plurality of the molds having different depths of the molding groove, and the molds are formed in the order of the molding groove. The configuration of using is adopted.

  According to an eighth invention, in any one of the fifth to seventh inventions, a main groove portion for making the material piece a target shape, and a position restriction formed on the outside of the main groove portion to restrict the position of the material piece. The structure using the said metal mold | die provided with a part is employ | adopted.

In the prior art, before the roll reaches the material piece, the roll applied with the load is pressed against the material piece as a state where a load is applied to the roll. That is, the starting point (weighted starting point) for weighting the roll is set outside the material piece.
When a load is applied to the roll, the roll and the mold are brought into close contact with each other. Therefore, when the material piece is not held and supported, it is difficult to enter between the roll and the mold. For this reason, conventionally, it has been necessary to hold the material piece.

On the other hand, according to the present invention, the material piece is placed on the mold, and the roll is pressed against the material piece with any position on the material piece placed on the mold as a load start point. .
That is, since no load is applied to the roll until the roll is moved onto the material piece, the roll can be easily moved onto the material piece.
For this reason, according to this invention, it becomes unnecessary to hold | grip a piece of material. Therefore, it is not necessary to provide the part to be gripped that has been discarded in the past with respect to the material piece, and the amount of material required for the material piece can be reduced.
Therefore, according to the present invention, the material pieces can be reduced in size by reducing the size of the material pieces.

It is a schematic block diagram of the press roll forging apparatus in one Embodiment of this invention. It is a top view of the metal mold | die with which the press roll forging apparatus in one Embodiment of this invention is provided. It is a figure which shows the shape of the metal mold | die used in Experimental example 1 relevant to this invention. It is a schematic diagram which shows the material piece shape | molded in Experimental example 1 relevant to this invention. It is a graph which shows the experimental result of Experimental example 1 relevant to this invention. It is a table | surface which shows the experimental result of Experimental example 2 relevant to this invention. It is sectional drawing of the metal mold | die used in Experimental example 3 relevant to this invention. It is a graph which shows the experimental result of Experimental example 3 relevant to this invention. It is a graph which shows the experimental result of Experimental example 4 relevant to this invention. It is an external view of the 1st metal mold | die used in Experimental example 6 relevant to this invention. It is an external view of the 2nd metal mold | die used in Experimental example 6 relevant to this invention. It is an external view of the 3rd metal mold | die used in Experimental example 6 relevant to this invention.

  Hereinafter, an embodiment of a press roll forming apparatus and a press roll forming method according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size. Moreover, in the following description, a press roll forging apparatus will be described as an example of the press roll forming apparatus of the present invention, and a press roll forging method will be described as an example of the press roll forming method of the present invention.

FIG. 1 is a schematic configuration diagram of a press roll forging device S1 of the present embodiment.
The press roll forging device S1 of the present embodiment performs molding of the material piece X by pressing the material piece X against the mold 2 with a roll (bottom roll 4).
As shown in FIG. 1, the press roll forging device S1 of the present embodiment includes a base 1, a mold 2, a mold rotating mechanism 3, and a bottom roll. 4 (roll), a top roll 5, a support frame 6, a slide mechanism 7, an upper block 8, a hydraulic device 9, and a control device 10 are provided.

  The base 1 includes a recess 1a that accommodates a mold 2 and a mold rotation mechanism 3 at the center. The depression 1a is set in a circular shape when viewed from above. In the base 1, the upper surface 1 b surrounding the recess 1 a functions as a receiving surface for the bottom roll 4.

The mold 2 is accommodated in the recess 1 a so that the upper surface 2 b is a receiving surface of the bottom roll 4 and is flush with the upper surface 1 b of the base 1.
The mold 2 includes a forming groove 2a (main groove) for forming the material piece X into a target shape. The molding groove 2 a is formed to be exposed on the upper surface 2 b of the mold 2.
And the material piece X is shape | molded by pressing the material piece X to the said shaping | molding groove part 2a, and being filled.

FIG. 2 is a top view of the mold 2. As shown in this figure, the shape in plan view is circular according to the recess 1 a of the base 1. And the metal mold | die 2 is equipped with the position control groove part 2c (position control part) in each position corresponded to the outer side of the shaping | molding groove part 2a, and the square vertex part surrounding the shaping | molding groove part 2a.
When the material piece X deforms between the mold 2 and the bottom roll 4, these position restricting groove portions 2 c move part of the material piece X by locking a part of the material piece X outside the molding groove portion 2 a. To regulate the position.
By providing such a position restricting groove 2c, it is possible to prevent the positional deviation of the material piece X during molding.

The position restricting groove 2c does not necessarily have to be formed at each position corresponding to the apex of the quadrangle surrounding the forming groove 2a, and an appropriate number may be disposed outside the forming groove 2a.
When the periphery of the molding groove 2a of the mold 2 is cut below the receiving surface of the bottom roll 4, a protruding portion is provided at a height that does not protrude above the receiving surface. Can be substituted for the position regulating groove 2c.

Further, in the press roll forging device S1 of the present embodiment, the mold 2 is fastened to the turntable 3a of the mold rotating mechanism 3 by a plurality of bolts 11, and can be easily removed by removing the bolts 11. It is configured to be removable.
Although only one mold 2 is shown in FIG. 1, the press roll forging device S1 of the present embodiment can be fastened to the turntable 3a of the mold rotating mechanism 3 in the same manner. A plurality of molds 2 are provided. The plurality of molds 2 are different in the shape of the molding groove 2a. And press roll forging device S1 of this embodiment shape | molds the material piece X in the target shape of the said metal mold | die 2 in each metal mold | die 2, and uses the some metal mold | die 2 with respect to the single material piece X. FIG. The material piece X is formed to a final target shape by gradually forming.
From the experimental results described later, it is preferable that the depths of the molding groove portions 2a of the plurality of molds 2 become shallower in the order in which they are used for the single material piece X. That is, when the material piece X is molded using a plurality of molds 2 having different depths of the molding groove 2a, it is preferable to use the molds 2 in descending order of the depth of the molding groove 2a.

The mold rotation mechanism 3 is for rotating the mold 2 with respect to the bottom roll 4 and the top roll 5, and as shown in FIG. 1, the turntable on which the mold 2 is fastened and fixed. 3a and a servo motor 3b for rotating the turntable 3a.
An elastic body 12 that is slidable with respect to at least one of the turntable 3 a and the base 1 is interposed between the lower surface of the turntable 3 a and the base 1. The elastic modulus of the elastic body 12 is set so that the upper surface 2 b of the mold 2 is flush with the upper surface 1 b of the base 1 when the mold 2 is pressed by the bottom roll 4.
The servo motor 3b is supported so as to be movable up and down with respect to the base 1 through a cushion material or the like. As a result, even when the mold 2 is pressed by the bottom roll 4, the servo motor 3b is prevented from being loaded.

The bottom roll 4 is in contact with the base 1 or the mold 2 and is arranged to be able to roll with the upper surface 1b of the base 1 or the upper surface 2b of the mold 2 as a receiving surface. Then, the bottom roll 4 forms the material piece X by pressing the material piece X against the mold 2.
The top roll 5 is disposed above the bottom roll 4 in contact with the bottom roll 4. The top roll 5 has a cylindrical shape similar to that of the bottom roll 4, and the rotation shaft is arranged parallel to the rotation axis of the bottom roll 4 and spaced apart in the vertical direction. The upper portion of the top roll 5 is in contact with the lower surface 8 a of the upper block 8, and the bottom roll 4 can be rotated by rotating between the upper block 8 and the bottom roll 4.

  The support frame 6 integrally supports the bottom roll 4 and the top roll 5 and is connected to the slide mechanism 7.

The slide mechanism 7 rotates the bottom roll 4 by pushing and pulling the support frame 6.
For example, in the arrangement relationship of FIG. 1, when the slide mechanism 7 pushes the support frame body 6, the bottom roll 4 moves toward the right side of the paper while rotating, and the slide mechanism 7 pulls the support frame body 6. As a result, the bottom roll 4 moves toward the left side of the sheet while rotating.

  The upper block 8 is disposed above the top roll 5, and the lower surface 8 a is parallel to the upper surface 1 b of the base 1 and the upper surface 2 b of the mold 2. A hydraulic device 9 is connected to the upper block 8 from the upper surface side.

  The hydraulic device 9 applies a load to the bottom roll 4 through the upper block 8 and the top roll 5 by pressing the upper block 8 from above (that is, the bottom roll 4 is loaded).

The control device 10 controls the entire operation of the press roll forging device S1 of the present embodiment, and controls the mold rotation mechanism 3, the slide mechanism 7 and the hydraulic device 9, and further external devices as necessary. Electrically connected.
And in the press roll forging device S1 of the present embodiment, the control device 10 controls any one of the positions on the material piece X placed on the mold 2 as a load start point by controlling the hydraulic device 9. A load is applied to the bottom roll 4 so as to be.
That is, in the press roll forging device S <b> 1 of the present embodiment, the pressing mechanism of the present invention is configured by the hydraulic device 9 and the control device 10.

  Next, the operation (press roll forging method) of the press roll forging device S1 of the present embodiment configured as described above will be described.

When the material piece X is placed on the mold 2, the control device 10 uses the slide mechanism 7 to remove the bottom roll 4 from the material piece without applying a load from the hydraulic device 9 to the bottom roll 4. Move up to X.
In addition, the control apparatus 10 detects the presence or absence of the material piece X and the position of the bottom roll 4 by the command from an operator and the sensor arrange | positioned as needed.

Then, after moving the bottom roll 4 onto the material piece X, the control device 10 applies a load to the bottom roll 4 by the hydraulic device 9. That is, the control device 10 presses the bottom roll 4 against the material piece X with the material piece X on the load start point.
Subsequently, the control device 10 moves the bottom roll 4 using the slide mechanism 7 and presses the entire material piece X against the mold 2.
Thereafter, the control device 10 controls the hydraulic device 9 to remove the load applied to the bottom roll 4, and further controls the slide mechanism 7 to remove the bottom roll 4 from the upper surface 2 b of the mold 2 to the upper surface of the base 1. Retreat up to 1b.

  When such a bottom roll 4 is retracted to the upper surface 1 b of the base 1, the control device 10 rotates the mold 2 by a predetermined angle (for example, 90 °) in the horizontal plane using the mold rotation mechanism 3, and again the bottom roll 4. The roll 4 is moved onto the material piece X, a load is applied, and the material piece X is pressed against the mold 2 and moved.

Then, the control device 10 repeats the rotation of the mold 2 and the pressing of the material piece X against the mold 2 as many times as necessary, thereby pressing the bottom roll 4 against the material piece X and moving it. The operation is performed from a plurality of different directions with respect to the piece X.
Thus, the material piece X is moved with respect to the molding groove 2a of the mold 2 by performing the operation of pressing the bottom roll 4 against the material piece X from a plurality of different directions. Can be reliably filled and the molding accuracy of the material piece X can be improved.

  When the material piece X is molded using a plurality of molds 2, the control device 10 retracts the bottom roll 4 from the upper surface 2 b of the mold 2 to the upper surface 1 b of the base 1, and the mold by the operator After waiting for the completion of the replacement operation of No. 2, the above operation is repeated again.

As described above, in the prior art, before the roll corresponding to the bottom roll 4 arrives at the material piece, it is assumed that a load is applied to the roll and the roll on which the load is applied is pushed against the material piece. Because of this, it was necessary to grip the piece of material.
On the other hand, according to the press roll forging device S1 and the press roll forging method of this embodiment, the material piece X is placed on the mold 2 and the material piece placed on the mold 2 is placed. The bottom roll 4 is pressed against the material piece X with any position on X as a load start point.
That is, until the bottom roll 4 is moved onto the material piece X, no load is applied to the bottom roll 4, so the bottom roll 4 can easily move onto the material piece X.
For this reason, according to the press roll forging device S1 and the press roll forging method of the present embodiment, it is not necessary to grip the material piece X. Therefore, it is not necessary to provide the material piece X with a portion to be gripped that has been discarded, and the amount of material required for the material piece X can be reduced.
Therefore, according to the press roll forging device S1 and the press roll forging method of the present embodiment, the material pieces can be reduced in size and discarded.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

Moreover, in the said embodiment, the structure using a metal mold | die was demonstrated.
However, the present invention is not limited to this, and a mold made of a material other than metal may be used instead of the mold.

Moreover, in the said embodiment, the structure which rotates the metal mold | die 2 using the metal mold | die rotation mechanism 3 was demonstrated.
However, the present invention is not limited to this, and the bottom roll 4 and the top roll 5 may be rotated with the mold 2 fixed.

Moreover, in the said embodiment, the structure using the plate-shaped metal mold | die 2 was demonstrated.
However, the present invention is not limited to this. For example, a roll-shaped mold can be used.

  An experimental example related to the press roll forging device S1 and the press roll forging method of the above embodiment will be described below. In the following description, pressing the material piece X with a roll may be referred to as rolling.

(Experimental example 1)
In this experiment, the material piece X was formed into a plate shape, and the influence of the change in the plate thickness was examined.
Table 1 shows the experimental conditions in this experimental example.

  FIG. 3 shows the mold used in this experimental example. In addition, (a) is a perspective view, (b) is sectional drawing. As shown in this figure, in this experimental example, a mold having a rectangular shape in plan view and a molding groove formed in a straight line from end to end was used.

And the value of each location of the material piece after shaping | molding shown in FIG. 4 was measured. In addition, (a) is a top view of the material piece after shaping | molding, (b) is a side view of the material piece after shaping | molding seen from the left-right direction of (a). Moreover, the filling rate (%) was calculated | required by the following formula.
Filling rate (%) = filling depth (mm) / shape depth (mm) × 100

  The measurement parameters shown in Table 2 were also obtained.

FIG. 5A is a graph plotting the relationship between the plate thickness and sink width obtained from this experimental example, and the relationship between the plate thickness and filling rate.
FIG. 5B is a graph plotting the relationship between the plate thickness and the elongation rate (center elongation rate and edge portion elongation rate) obtained from this experimental example.

As can be seen from FIG. 5, in the present experimental example, it was confirmed that as the plate thickness increased, the sink width decreased and at the same time the filling rate increased.
Here, in this experimental example, the pass schedule is the same regardless of the change in the plate thickness, so that the initial reduction amount increases and the deformation amount increases as the plate thickness increases.
That is, it is considered that sinking is less likely to occur as the amount of deformation increases.

Also, the elongation rate of the length is higher as the plate thickness is thicker. This can be said that as the plate thickness is increased, the amount of deformation due to the initial reduction increases, so that the amount to be rolled increases and the elongation in the rolling direction becomes longer.
Further, the difference in elongation between the central portion and the edge portion is considered to be due to the difference in each reduction.

(Experimental example 2)
From Experimental Example 1, it was found that the larger the initial plate thickness, the higher the filling ratio, but in this Experimental Example, the plate width was further changed.
Table 3 shows the experimental conditions in this experimental example. The condition indicated by “◯” is the result of the experiment.

  Table 4 shows the yield under each experimental condition.

  In addition, the pass schedule (rolling process until reaching the final target shape) in this experimental example is set to a thickness of 1.3 mm in the first pass (the first rolling process), and the second pass (the second pass). In the third rolling step (rolling step), the plate thicknesses were set to 0.6 mm and 0.3 mm, respectively. However, for the test conditions with a plate thickness of 3.6 mm and a plate width of 30 mm, the plate thickness could not be reduced to 1.3 mm by one rolling, and the rolling was performed in two steps. Moreover, in order to reduce a rolling load after 1 pass and 2 passes, the burr | flash part (refer FIG. 4) was cut off with the fine cutter.

  FIG. 6A is a table showing the result of evaluation of filling based on whether the material piece has reached the edge of the forming groove, and FIG. 6B is a decrease in plate thickness due to sink marks. Is a table showing the results of evaluation with a maximum value of 0.05 mm or less as “◯”, a value of up to 0.1 mm as “Δ”, and a value higher than that as “x”.

In FIG. 6B, the reason why the material did not spread to the edge portion at 2.8 mm × 30 mm, 3.2 mm × 30 mm, 3.4 mm × 30 mm is considered to be due to a problem in how to place the material. In order to spread the material to the edge portion with a smaller plate width, measures such as placing the material in consideration of the bending of the material or providing a guide can be considered.
At 3.6 mm × 30 mm, the formability at the edge portion was poor, but this is considered to be because the material was not filled into the edge portion due to the elongation of the material.

As for the plate thicknesses of 3.4 mm and 3.6 mm, they were completely filled in one pass, but sink marks occurred in the third pass. This means that the reduction amount of the first pass is 2.1 mm when the plate thickness is 3.4 mm, and 2.3 mm when the plate thickness is 3.6 mm, while the depth of the deepest part of the forming groove is 2.1. It is thought that. Moreover, although the total reduction amount exceeds 2.1 mm even at a plate thickness less than that, it is considered that sink marks have occurred by dividing the rolling into a plurality of times. Further, even if the filling is performed in the first pass or the second pass, it is lost in the third pass with a small reduction amount. From the above, it is considered that the factor that greatly affects the filling is the reduction amount rather than the initial plate thickness.
Therefore, as a method of completely filling in the last pass, the following can be considered.
(1) All of the material pieces are made to enter the forming groove from the beginning, and the substantial reduction amount is increased.
(2) In the final pass where the amount of reduction is small, the thickness of the thick portion is reduced. Therefore, the second pass is filled deeper than the final shape.

  In this experimental example, warpage occurred in all the material pieces in the first pass. Further, even a piece of material after the final pass without a burr portion has a large warp. In the first place, it is thought that the material pieces are warped due to the difference in the vertical elongation of the material pieces. On the other hand, since the burr part is generated only on the bottom roll surface side, it is considered that there is an action of suppressing warpage. For this reason, it is considered that the initial material piece needs to have a width sufficient to generate a certain amount of burrs in the final pass.

(Experimental example 3)
In the present experimental example, a mold having a flat shoulder as shown in FIG. 7A (flat mold) and a mold having an inclination as shown in FIG. 7B. We verified how the load during molding differs between the mold (inclined mold).
At the same time, we compared the influence of these molds on the material pieces such as “sink” and thickness distribution. In addition, since the influence with respect to a piece of material may not become remarkable when the shape of a metal mold | die is complicated, the width direction cross-sectional shape of the metal mold | die was always fixed.
Table 5 shows the experimental conditions in this experimental example.

  In addition, FEM analysis was performed with plate widths 26, 28, and 30 using a flat mold and an inclined mold, respectively, and the load of the mold was compared. Table 6 shows the analysis conditions.

FIG. 8 is a graph showing the results obtained by this experimental example, and is a graph showing the relationship between the plate width of the material piece and the load.
From these results, it can be confirmed that the inclined mold has a half load compared to the flat mold. However, in the analysis value, the slanted mold had a slightly lower load, but the difference in load was not so much.
For flat molds, it can be confirmed that the experimental value and the analytical value are almost the same. However, if the plate width is increased and the burr is generated, the experimental value load exceeds the analytical value by nearly 1t. It was. On the other hand, there was little agreement regarding the inclined mold.

(Experimental example 4)
In Experimental Example 1 and Experimental Example 2, the influence on the filling by the plate width and the plate thickness of the material piece was investigated. In this Experimental Example, the influence of the width expansion by the plate width is investigated. In this experimental example, the change in sheet width when rolling was measured for each initial sheet width.
The material piece used in this experimental example has a plate thickness of 2.8 mm, a plate length of 40 mm, and initial plate widths of 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, and 32 mm. Further, the pass schedule in this experimental example was 1 pass, 1.3 mm.

About each material piece, the longitudinal direction center part was cut | disconnected with the fine cutter, and the cross-sectional area was measured. In this experimental example, the breadth was evaluated using the difference in cross-sectional area from the case where there was no breadth.
FIG. 9A shows a graph in which the cross-sectional area is changed for each initial plate width, and FIG. 9B shows a graph in which the width is increased for each initial plate width.

As shown in FIG. 9B, it can be seen that the wider the initial plate width is, the larger the width is.
Think about this cause. Usually, it does not extend in the width direction in rolling, and the amount of reduction is all the elongation of the material. However, in a press roll, since the reduction varies depending on the location, the elongation varies depending on the location. Furthermore, since there is a restriction by the material itself, it cannot grow as much as the original elongation rate depending on the location. Therefore, it is thought that the part which was not extended spreads in the width direction.
In addition, when the initial plate width is small, the reduction does not change much depending on the location because it is placed in the center of the mold, but when the initial plate width is large, the material reaches the edge of the molding groove, so there is a difference in reduction. Is big. Thus, it is considered that when the plate width is small, it does not widen in the width direction, and when the plate width is large, it widens greatly in the width direction.

(Experimental example 5)
With existing normal rolling, it is difficult to achieve a yield of 50%. Therefore, it is conceivable to employ cross rolling (a method of rolling a plurality of times from different directions) in order to further improve the yield. However, this method has a disadvantage that the load becomes too large because a large portion of reduction is rolled at a time.
Therefore, in order to reduce the load at the time of cross rolling, considering the step of thinning the edge portion in advance by normal rolling, the first pass (normal rolling) → the second pass (cross rolling) → the third pass ( Normal rolling).
In addition, normal rolling means rolling along the extending direction of a forming groove part, and cross rolling means rolling in the direction orthogonal to normal rolling.
Table 7 shows the pass schedule of this experimental example. In addition, the dimensions of the material pieces in this experimental example were a plate thickness of 2.8 mm, a plate width of 22 mm, and a plate length of 35 mm. Moreover, the yield in this experiment example was 74.5%.

As a result of the experiment, extremely good results were obtained for filling under conditions 1 and 2 shown in Table 7. Furthermore, in condition 1 and condition 2, an extremely large number of burrs were not generated, and in condition 2, it was confirmed that the material spread to the edge part.
In past experiments, when applying 60% reduction by cross-rolling, the load was too large and it had to be rolled multiple times. In contrast, in this experimental example, although the load could not be measured, the second pass cross-rolling could be performed at a time. Therefore, it was found that the load during cross rolling can be reduced by using this process.

  In addition, although the experiment by the pass schedule shown in Table 8 was also performed, the favorable result was not obtained about filling.

(Experimental example 6)
Next, the experimental results of rolling using the three types of molds shown in FIGS.

In the mold shown in FIG. 10 (hereinafter referred to as the first mold), the depth of the molding groove of the mold was increased for the purpose of filling as deeply as possible in the first pass. Specifically, the shape of the molding groove portion of the first mold was a shape in which the final target shape of the material piece was multiplied by 1.2 in the thickness direction and the upper part was cut out by 0.3 mm. Further, the first pass mold is not provided with the constricted part so that the constricted part is filled more in the second and subsequent passes, and the cross-sections of the two uniform cross-sectional parts are smoothly connected. Further, the molding groove extends to the end of the mold.
The shoulder of the first mold was provided with a 20 ° inclination. Further, flat portions were provided on both sides. This flat portion has the same height as the highest portion of the region sandwiched between the flat portions of the first mold, and was used to measure the gap between the bottom roll and the mold during the experiment.

The shape of the forming groove portion of the mold shown in FIG. 11 (hereinafter referred to as the second mold) was obtained by multiplying the final target shape by 1.1 in the thickness direction and cutting the upper part by 0.3 mm. Further, similarly to the first mold, a 20 ° inclination was provided on the shoulder, and flat portions were provided on both sides.
Moreover, in the 2nd metal mold | die, protrusion was provided in the bottom part of the shaping | molding groove part in the form which avoids the area | region which forms the area | region which will be used as a final product. The width of the protrusion was 5 mm, the diameter was 5 mm, and the fillet was 0.5 mm. The height of the protrusion was a height lowered in the thickness direction by 1 mm from the highest portion of the region sandwiched between the flat portions. Further, the protrusion is formed 1 mm away from an area that forms an area to be used as a final product.

   The shape of the molding groove portion of the mold shown in FIG. 12 (hereinafter referred to as the third mold) was a shape in which the final target shape was cut off by 0.3 mm without changing the thickness. Further, similarly to the first mold and the second mold, a 20 ° inclination was provided on the shoulder. Also, the height of the flat part is higher than the highest part of the area surrounded by the flat part so that a frame-like flat part is provided and the thickness of the burr part formed on the material piece is 0.3 mm. Is also set higher by 0.3 mm. Moreover, the same protrusion as the 2nd metal mold | die is formed.

  And it rolled on the conditions shown in Table 9. In addition, the dimension of the material piece in this experiment example was made into board thickness 2.8mm, board width 22mm, and board length 35mm.

In Experiment 1, sink marks occurred at the center of the material piece after molding, and the material piece did not extend so much in the width direction because of normal rolling, so the plate width could not be shortened, and the yield was 55.2%. It is had.
In Experiments 2, 3, and 4 incorporating cross rolling, the yield was greatly improved, and filling was improved by changing the deformation amount and plate width of the burr thickness. Further, in Experiments 5 and 6 in which the number of steps was omitted in two passes, the upper part of the material piece after molding was not flat, but a result with good filling and high yield was obtained.

  S1: Press roll forging device (press roll forming device), 1 ... Base, 1a ... Depression, 1b ... Upper surface, 2 ... Mold, 2a ... Molding groove (main groove), 2b ... Upper surface, 2c: Position restricting groove (position restricting portion), 3 ... Mold rotating mechanism, 3a ... Turntable, 3b ... Servo motor, 4 ... Bottom roll (roll), 5 ... Top roll, 6 ... ... support frame, 7 ... sliding mechanism, 8 ... upper block, 8a ... bottom surface, 9 ... hydraulic device, 10 ... control device, 11 ... bottle, 12 ... elastic body

Claims (6)

A press roll forming apparatus comprising a mold and forming the material piece by pressing the material piece against the mold by a roll,
A pressing mechanism that presses the roll against the material piece with any position on the material piece placed on the mold as a load start point ;
A press roll molding apparatus comprising a plurality of molds used for a single piece of material, wherein the depth of the molding groove of the mold becomes shallower in the order of use .   The press roll forming apparatus according to claim 1, further comprising a mold rotating mechanism that rotates the mold with respect to the roll. The said metal mold | die is equipped with the main groove part for making the said material piece into the target shape, and the position control part which is formed in the outer side of this main groove part, and controls the position of the said material piece, or characterized by the above-mentioned. 2. A press roll forming apparatus according to 2. A press roll forming method for forming the material piece by pressing the material piece against a mold by a roll,
The material piece is placed on the mold, the roll is pressed against the material piece with a load starting point at any position on the material piece placed on the mold ,
A press roll forming method , wherein a single piece of material is formed using a plurality of dies having different depths of the forming groove portions, and the dies are used in descending order of the forming groove portions . The press roll forming method according to claim 4, wherein the roll is pressed against the material piece from a plurality of different directions. A main groove for the purpose shape the material strip, claim 4 or characterized by using the mold formed on the outside of the main groove and a position regulating portion for position regulating the material piece 5. The press roll forming method according to 5 .

Images