JP5281521B2 - Bending member manufacturing method and bending apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a bent member which is hard to generate wrinkles and projecting and recessing parts although performing complicated working control. <P>SOLUTION: In the method of manufacturing the bent member having a bent part by restraining both ends of a hollow shape material K respectively with rotary receiving bases 1, 1 which are supported rotatably and imparting pressurizing force to the hollow shape material K in such a state, the hollow shape material K is restrained by the rotary receiving bases 1, 1 in such a manner that the minimum separated distance e between the inside edge Ka of the hollow shape material K and the center line P of rotation of the rotary receiving base 1 satisfies the following expression and the pressurizing force in a direction along a plane taking the center line P of rotation as the normal line is imparted to the hollow shape material K while keeping the separated distance L of the center lines P, P of rotation of the rotary receiving bases 1, 1 constant. äS-(1+a)&times;L/2+h&times;&theta;}/tan&theta;&lt;e&le;äS-(1-a/5)&times;L/2}/tan&theta; [where, S is a reference length (=r&times;&theta;+(L/2-rsin&theta;)/cos&theta;); r is the bend radius (mm); 2&theta;is a bend center angle (rad); h is the girder height (mm) of the hollow shape material; and a is the tensile breaking strain of a material which comprises the hollow shape material]. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a bending member having a bending portion and a bending apparatus.

  A bending member manufacturing method for manufacturing a bending member by curving a linear hollow profile is disclosed in Patent Document 1 and the like. In the manufacturing method of the bending member of Patent Document 1, both ends of the hollow shape member are held by a pair of holding means (chucks) that rotate about a horizontal axis, and the horizontal axis of one holding means and the horizontal of the other holding means are horizontal. The pressing force (pressing device) applies a pressing force to the hollow shape member while narrowing the separation distance from the shaft.

JP-A-6-142805

  According to the manufacturing method of the bending member of Patent Document 1, it is difficult for irregularities and wrinkles to occur in the outer shell of the hollow shape inside the bend, but the extruded shape while reducing the interval between the pair of holding means for holding the extruded shape. Therefore, the configuration of the bending apparatus becomes complicated, and the control of the bending apparatus becomes complicated.

  From such a viewpoint, the present invention provides a method for manufacturing a bent member that is less likely to cause wrinkles and unevenness without performing complicated processing control, and has a simple configuration suitable for the method for manufacturing the bent member. It is an object to provide an apparatus.

The manufacturing method of the bending member according to the present invention that solves the above-described problem is that the both ends of the hollow shape member to be bent are constrained to a turntable that is rotatably supported, and the hollow member is in this state. A method of manufacturing a bending member having a curved portion by applying a pressing force to a shape member, wherein a minimum separation distance e between a bent inner edge of the hollow shape member and a rotation center line of the turntable is The hollow shape member is constrained to the rotation cradle so as to satisfy the following formula, and the separation distance L between the rotation center line of one of the rotation cradle and the rotation center line of the other rotation cradle is constant. A pressing force in a direction along a plane having the rotation center line as a normal line is applied to the hollow shape member while being maintained.
{S− (1 + a) × L / 2 + h × θ} / tan θ <e ≦ {S− (1−a / 5) × L / 2} / tan θ
S: Reference length (mm) = r × θ + (L / 2−r × sin θ) / cos θ
r: Bending radius (mm)
2θ: bending center angle (rad)
h: Girder height of hollow profile (mm)
a: Tensile breaking strain of the material constituting the hollow profile

  In the present invention, since it is not necessary to vary the separation distance L between the rotation center lines of the pair of rotation cradle when applying the pressing force, complicated control for the bending apparatus becomes unnecessary. That is, according to the present invention, the bending member (the bending member) can be simply adjusted by adjusting the minimum separation distance e between the bending inner edge of the hollow shape member and the rotation center line of the turntable within the range defined by the above equation. Since wrinkles and irregularities generated in the outer shell of the hollow shape material after processing can be suppressed, the manufacturing efficiency can be improved and the manufacturing cost can be reduced.

  A bending apparatus according to the present invention that solves the above-described problems includes a pair of turntables that are rotatably supported, and a bending die that is pressed against a hollow shape member that is to be bent. By pressing the hollow shape member against the bending die in a state where the end portion is constrained to the rotation cradle, the hollow shape material is pressed in a direction along a plane with the rotation center line of the rotation cradle as a normal line. The rotating cradle includes an adjusting mechanism capable of adjusting a separation distance between a bending inner edge of the hollow shape member and the rotation center line.

  According to the present invention, the bending member manufacturing method according to the present invention can be easily realized.

  Although there is no restriction | limiting in the structure of an adjustment mechanism, For example, the said rotation receiving stand is interposed between the receiving seat which receives the pressing force provided to the said hollow shape material, and the said hollow shape material and the said seat. When the spacer is detachable with respect to the rotating cradle, the restraining position of the hollow shape member may be adjusted by attaching or detaching or replacing the spacer. . If it does in this way, the minimum separation distance of the bending inner edge of a hollow shape material and the rotation center line of a turntable can be adjusted easily and rapidly.

  When the restraint jig for restraining the end of the hollow shape member to the rotation cradle and the rotation cradle has an insertion space into which the hollow shape material can be inserted, The restraining jig may be attached to the hollow shape member that protrudes to the side of the rotation receiving table through the insertion space of the rotation receiving table. The bending process using the bending apparatus according to the present invention may be a so-called tensile bending process in which a tensile force is generated in the axial direction of the hollow profile, but it is constrained to the end of the hollow profile projecting from the rotary cradle. If the jig is attached, it is possible to prevent the hollow shape member from coming out of the rotation cradle, so that the processing accuracy can be improved.

According to the method for manufacturing a bending member according to the present invention, it is difficult for wrinkles and irregularities to occur on the outer skin of the bending member without performing complicated processing control.
Moreover, according to the bending apparatus which concerns on this invention, it becomes possible to implement | achieve easily the manufacturing method of the bending member which concerns on this invention.

It is sectional drawing for demonstrating the manufacturing method and bending apparatus of the bending member which concern on embodiment of this invention, (a) is a figure which shows the state before a bending process, (b) is the state after a bending process. FIG. It is a schematic diagram for demonstrating the manufacturing method of the bending member which concerns on embodiment of this invention, Comprising: (a) is a figure which shows the state before a bending process, (b) is a figure which shows the state after a bending process. . It is a perspective view for demonstrating the bending apparatus which concerns on embodiment of this invention. It is a disassembled perspective view for demonstrating the bending apparatus which concerns on embodiment of this invention. It is sectional drawing for demonstrating the structure of a rotation receiving stand and a base. It is sectional drawing for demonstrating the structure of a restraining jig | tool. (A) is a side view showing a state where a spacer is attached, (b) is a cross-sectional view taken along line II-II of (a), (c) is a side view showing a state where the spacer is removed, and (d) is (c). It is the III-III sectional view taken on the line. (A) And (b) is a typical top view for demonstrating the bending apparatus which concerns on other embodiment of this invention.

  As shown in FIGS. 1 (a) and 1 (b), the bending member manufacturing method according to the present embodiment is such that each end of the hollow shape member K to be bent is rotatably supported. This is a method of manufacturing a bending member K ′ having a curved portion by restraining the cradle 1 and applying a pressing force to the hollow shape member K in such a state. 1 is a cross-sectional view taken along the line II of FIG.

  Below, the case where bending is performed by pressing the contact surface 5a of the bending die 5 against the bending inner edge (hereinafter, simply referred to as “inner edge”) Ka of the hollow shape member K will be exemplified. The contact surface 5a of the bending die 5 has an arc surface (cylindrical surface). Incidentally, the hollow profile K of the present embodiment is an extruded profile made of an aluminum alloy having a cross-sectional “day” shape.

In short, the manufacturing method of the bending member according to the present embodiment has a minimum separation distance e between the inner edge Ka of the linear hollow member K which is the element of the bending member K ′ and the rotation center line P of the rotating cradle 1. The hollow shape member K is constrained to the rotation bases 1 and 1 so as to satisfy the following formula (1), and the rotation center line P of one rotation reception base 1 is separated from the rotation center line P of the other rotation reception base 1. While keeping the distance L constant, a pressing force F in a direction along a plane (a plane parallel to the paper surface in FIG. 1) having the rotation center line P as a normal line is applied to the hollow shape member K.

{S− (1 + a) × L / 2 + h × θ} / tan θ <e ≦ {S− (1−a / 5) × L / 2} / tan θ
... (1)
here,
S: Reference length (mm) = r × θ + (L / 2−r × sin θ) / cos θ
r: Bending radius (= radius of contact surface 5a) (mm)
2θ: bending center angle (= center angle corresponding to the arc of the contact surface 5a) (rad)
h: Girder height of hollow profile (mm)
a: Tensile breaking strain of the material constituting the hollow profile.

  The bending radius r and the bending center angle 2θ (see FIG. 2) are the radius and center angle of the curved portion of the bending member K ′ (see FIG. 1B) in the state where the pressing force F is applied. In the embodiment, it is equal to the radius and the central angle of the contact surface 5a. Incidentally, when the pressing force F is unloaded, a springback is generated in the bending member K ′. Therefore, the radius and center angle of the curved portion of the bending member K ′ after the unloading of the pressing force F are the bending radius r and the bending angle. It may be different from the central angle 2θ.

  With reference to the schematic diagram of FIG. 2, the manufacturing method of the bending member which concerns on this embodiment is demonstrated in detail. Here, FIG. 2A is a plan view showing the hollow member K before bending, and the apex (tip) of the contact surface 5a of the bending die 5 is in contact with the inner edge Ka. FIG. 2B is a diagram showing a state in which the bending die 5 is stroked from the state of FIG. 2A by the distance y. Note that the bending radius r and the bending center angle 2θ shown in FIG. 2 are different from those in FIG. 1 because of drawing.

  Here, the point A in FIG. 2 is a point on the inner edge Ka of the hollow shape member K (or the bending member K ′) that has the shortest distance from the rotation center line P. A ”. Further, the point C is a point on the inner edge Ka located exactly in the middle of the inner reference points A and A, and is hereinafter referred to as “inner center point C”. Similarly, a point A ′ in FIG. 2 is a point on the bending outer edge (hereinafter, simply referred to as “outer edge”) Kb of the hollow shape member K having the shortest distance from the rotation center line P. Hereinafter, it is referred to as “outer reference point A ′”. The point C ′ is a point on the outer edge Kb located exactly in the middle of the outer reference points A ′ and A ′, and is hereinafter referred to as “outer center point C ′”.

  When the bending die 5 brought into contact with the inner center point C of the hollow shape member K is moved toward the outer edge Kb in a state where the position of the rotation center line P of the rotation cradle 1 is fixed, The center portion of the inner edge Ka is curved with a bending radius r (that is, the radius of the contact surface 5a of the bending die 5) following the shape of the contact surface 5a of the bending die 5, and the center portion of the outer edge Kb is bent. Curved by a radius (= r + h) obtained by adding the digit height h of the hollow shape member K to the radius r, and, further, as the rotation cradle 1 (see FIG. 1) rotates around the rotation center line P, The end of the hollow member K is inclined at an angle equal to the rotation angle of the turntable 1.

  When the bending die 5 is moved by a distance y in a direction orthogonal to the longitudinal direction of the hollow shape K before bending, the contact surface 5a of the bending die 5 among the inner edges Ka of the hollow shape K. 2 is deformed into an arc having a radius r and a center angle 2θ, and further, the central portion of the outer edge Kb of the hollow member K is deformed into an arc having a radius r + h and a center angle 2θ (FIG. 2B). reference).

  The stroke amount (= distance y) of the bending die 5 is such that the straight line from the end point B of the bending portion of the bending member K ′ to the inner reference point A is the edges 5b, 5b ( It is set so as to coincide with the tangent line in FIG. A method for calculating the stroke amount y will be described later.

By the way, whether or not wrinkles or irregularities are generated in the outer skin of the bending member K ′ formed by bending the hollow shape member K depends on the strain generated on the inner edge Ka of the bending member K ′ (hereinafter referred to as “inner edge strain”). It correlates with the magnitude of ε _c .

The inner edge strain ε _c is expressed by the following equation (3), where x is the length of the line segment AC of the bending member K ′ and L / 2 is the length of the line segment AC of the hollow profile K before bending. It can ask for.
ε _c = x / (L / 2) −1 (3)

The length S _{1 of} the line segment BC, the length S ₂ of the line segment BD, and the length S ₃ of the line segment AD in the bending member K ′ are respectively
S ₁ = r × θ (4)
S ₂ = {L / 2−r × sin θ} / cos θ (5)
S ₃ = e × tanθ (6)
Therefore, the length x of the line segment AC of the bending member K ′ is
x = S ₁ + S ₂ −S ₃
= R × θ + {L / 2−r × sin θ} / cos θ−e × tan θ
= S−e × tan θ (7)
It becomes. “S” in Expression (7) is the reference length S defined in Expression (1). That is, the length (= S ₁ + S ₂ ) of the line segment CD in the bending member K ′ before unloading the pressing force F is the “reference length” in the equation (1).

By the way, the bumper reinforcement used in a general passenger car is a hollow extruded shape made of JIS standard 6000 series or 7000 series aluminum alloy and has a plate thickness set in a range of 1.5 mm to 4 mm. Extruded profiles are used. In the case of this hollow extruded profile, empirically, if the inner edge strain ε _{c is set} to −0.03 or more (tensile is set to “positive”), bending will occur. If no wrinkles or irregularities are generated on the inner skin of the member K ′ and the outer edge Kb of the bent member K ′ (hereinafter referred to as “outer edge strain”) ε _t is 0.15 or less. In addition, it is known that there is no occurrence of tensile breakage or rough ground in the outer skin of the bending member K ′.
As a result of considering the above findings, a general condition for preventing wrinkles, irregularities and the like from being generated on the outer skin of the bending member K ′ on the inner side of the bending is set as the following equation (8).
ε _c ≧ −a / 5 (8)
a: Tensile breaking strain of the material constituting the hollow member K

By substituting the equations (3) and (7) into the equation (8) and solving for the minimum separation distance e, a conditional equation (9) for preventing wrinkles and irregularities from being generated on the bending member K ′ is derived.
e ≦ {a / 5 × (L / 2) −1 + S} / tanθ (9)

Further, as described above, whether or not a tensile break or rough surface occurs in the outer skin of the bending member K ′ correlates with the magnitude of the outer edge strain ε _t .

As for the outer edge strain ε _t , when the length of the line segment A′C ′ of the bending member K ′ is x ′, the length of the line segment A′C ′ of the hollow shape member K before bending is L / 2. From the above, it can be obtained by the following equation (10).
ε _t = x ′ / (L / 2) −1 (10)

The length S ₁ ′ of the line segment B′C ′, the length S ₂ ′ of the line segment B′D ′, and the length S ₃ ′ of the line segment A′D ′ in the bending member K ′ are respectively
S ₁ ′ = (r + h) × θ (11)
S ₂ ′ = {L / 2− (r + h) × sin θ} / cos θ (12)
S ₃ ′ = (e−h) × tan θ (13)
Therefore, the length x ′ of the line segment A′C ′ of the bending member K ′ is
x ′ = S ₁ ′ + S ₂ ′ −S ₃ ′
= (R + h) × θ + {L / 2− (r + h) × sin θ} / cos θ
− (E−h) × tan θ
= R × θ + {L / 2−r × sin θ} / cos θ + h × θ−e × tan θ
= S + h × θ−e × tan θ (14)
It becomes.

As a result of considering the above-mentioned knowledge in the case of bumper reinforcement, general conditions for preventing the occurrence of tensile breakage, rough ground, etc. in the outer skin of the bending member K ′ on the outer side of the bending are expressed by the following equation (15). It was decided to set as follows.
ε _t <a (15)
In the case of a JIS standard 6000 series or 7000 series aluminum alloy, it is desirable that ε _t <0.15.

Substituting Equations (10) and (14) into Equation (15) and solving for the minimum separation distance e yields Conditional Equation (16) for preventing the occurrence of tensile rupture or rough ground on the outer skin of the bending member K ′. It is burned.
e> {S− (1 + a) × L / 2 + h × θ} / tan θ (16)

Since the combination of Expression (9) and Expression (16) is Expression (1), Expression (1) is a constant distance L between the rotation center lines P and P of the rotation cradle 1 and 1. It can be said that this is a general condition for preventing wrinkles, unevenness, tensile breakage, ground roughness, and the like when performing bending while maintaining the thickness.
Incidentally, in the case of a JIS series 6000 series or 7000 series aluminum alloy, a = 0.15 in formula (1), so the following formula (1 ′) is obtained.
{S-1.15 × L / 2 + h × θ} / tan θ <e ≦ {S−0.97 × L / 2} / tan θ
... (1 ')

The stroke amount y of the bending die 5 is calculated by the following equation (17).
y = (1-cos θ) × r + (S ₂ −S ₃ ) × sin θ + (1-cos θ) × e
= (1-cos θ) × (r + e) + {L / 2− (r + e) × sin θ} × tan θ
... (17)

  Thus, according to the manufacturing method of the bending member which concerns on this embodiment, since it is not necessary to change the separation distance L of the rotation centerlines P and P, the complicated control with respect to a bending processing apparatus becomes unnecessary. That is, according to the manufacturing method of the bending member according to the present embodiment, the minimum separation distance e between the inner edge Ka of the hollow shape member K and the rotation center line P of the turntable 1 is a range defined by the equation (1). Therefore, it is possible to obtain a bent member K ′ having no wrinkles or irregularities on the inner skin of the bend and no cracks on the outer skin of the bend, so that the manufacturing efficiency is improved. Manufacturing costs can be reduced.

  Next, with reference to FIGS. 3 to 7, the configuration of the bending apparatus 100 capable of implementing the above-described bending member manufacturing method will be described in detail.

  As shown in FIG. 3, the bending apparatus 100 includes a pair of turntables 1, 1 that are rotatably supported, and a bending die 5 that is pressed against the hollow shape member K to be bent. The bending apparatus 100 according to this embodiment includes pedestals 2 and 2, spacers 3 and 3, and restraining jigs 4 and 4, in addition to the rotating cradle 1 and the bending die 5.

  The rotation cradle 1 supports the end of the hollow member K, and includes an insertion space 1a (see FIG. 4) into which the hollow member K can be inserted. The rotation cradle 1 is supported so as to be rotatable about a rotation center line P. The left and right rotation cradles 1 and 1 are arranged at the same height in the present embodiment so that the hollow profile K is parallel to a plane (horizontal plane in the present embodiment) having the rotation center line P as a normal line. ing. The left and right rotation center lines P and P are parallel to each other.

  Although there is no restriction | limiting in the structure of the rotation receiving stand 1, as shown in FIG. 4, the thing of this embodiment is the receiving seat 11 which receives the pressing force provided to the hollow shape member K, and the lower end part of this receiving seat 11 And a lower support portion 12 projecting toward the bending die 5 side, and an upper support portion 13 projecting from the upper end portion of the receiving seat 11 toward the bending die 5 side. Yes.

  The lower support portion 12 is disposed along a plane having the rotation center line P as a normal line, and a pin insertion hole 12a having a circular shape in plan view is formed in the center portion in the width direction. A shaft portion 24a of a pin 24 described later is inserted into the pin insertion hole 12a. The upper support portion 13 is disposed along a plane having the rotation center line P as a normal line, and a pin insertion hole 13a having a circular shape in plan view is provided at a position corresponding to the pin insertion hole 12a of the lower support portion 12. Is formed. A shaft portion 25a of the pin 25 described later is inserted into the pin insertion hole 13a. Further, the lower support portion 12 and the upper support portion 13 are opposed to each other with an interval at which the hollow shape member K can be inserted. That is, an insertion space 1 a in which the hollow shape member K can be inserted is secured between the lower support portion 12 and the upper support portion 13.

  The pedestal 2 supports the turntable 1 in a rotatable manner, and includes a base 2A fixed to a gantry (not shown) in a state in which translation is impossible, and a pedestal main body 2B fixed to the upper surface of the base 2A. ing.

  As shown in FIG. 5, the base 2 </ b> A is disposed along a plane having the rotation center line P as a normal line, and a counterbore-shaped through hole 20 a is formed at an appropriate position of the base 2 </ b> A. A flange portion of the pin 24 described later is accommodated in the counterbore portion of the through hole 20a.

  The pedestal main body 2 </ b> B holds the rotation receiving base 1, and includes an upright portion 21, a lower receiving portion 22 projecting from the lower end portion of the upright portion 21 toward the rotation center axis P, and an upper end portion of the upright portion 21 And a pair of upper and lower pins 24 and 25 arranged coaxially.

  The upright portion 21 and the lower receiving portion 22 are placed on the upper surface of the base 2A, and are fixed to the base 2A by means such as welding. A pin insertion hole 22a corresponding to the through hole 20a of the base 2A is formed in the lower receiving portion 22. The upper receiving part 23 is opposed to the lower receiving part 22 with an interval slightly larger than the height dimension of the rotary cradle 1.

  The lower pin 24 is inserted into the through hole 20a and the pin insertion hole 22a from the lower surface side of the base 2A, and is fixed to the base 2A by a bolt (not shown) inserted through the flange portion. The shaft portion 24 a of the pin 24 protrudes above the lower receiving portion 22 and is inserted into the pin insertion hole 12 a of the rotation receiving base 1.

  The upper pin 25 is inserted into the pin insertion hole 23a from the upper surface side of the upper receiving portion 23, and is fixed to the upper surface of the upper receiving portion 23 by a bolt (not shown) inserted through the flange portion. The shaft portion 25 a of the pin 25 protrudes below the upper receiving portion 23 and is inserted into the pin insertion hole 13 a of the rotation receiving base 1.

  The tip surfaces of the pins 24 and 25 are opposed to each other with the insertion space 1a of the rotation cradle 1 interposed therebetween. That is, the front end surface (upper end surface) of the lower pin 24 is substantially flush with the upper surface of the height adjustment plate 14 laid on the upper surface of the lower support portion 12 of the rotary cradle 1. The front end surface (lower end surface) of 25 is substantially flush with the lower surface of the upper support portion 13. In the present embodiment, the center line of the pins 24 and 25 is the rotation center line P of the rotation cradle 1. However, since the pins 24 and 25 are fixed to the base 2 that cannot be translated, the rotation center line P Is not translatable (immovable). The pins 24 and 25 are attached to the base 2 after the rotation receiving base 1 is disposed between the lower receiving portion 22 and the upper receiving portion 23.

  The spacer 3 is a member that functions as an adjusting mechanism that adjusts the shortest separation distance e between the inner edge Ka of the hollow shape member K and the rotation center line P. In the insertion space 1 a of the turntable 1, the spacer 3 It is interposed between the seats 11. The spacer 3 is only placed on the height adjusting plate 14 laid on the upper surface of the lower support portion 12 and can be attached to and detached from the rotary cradle 1. Incidentally, fixing the spacer 3 to the rotating cradle 1 using a bolt or a vise does not hinder the detachable mounting state. The configuration of the spacer 3 is not limited, but it is desirable that the spacer 3 has rigidity so that the shortest separation distance e does not change during bending.

  The restraining jig 4 shown in FIG. 4 restrains the end of the hollow shape member K protruding from the insertion space 1a of the turntable 1 to the turntable 1, and in this embodiment, the hollow shape member K is used. Is prevented from slipping out toward the bending mold 5 side. Although there is no restriction | limiting in the structure of the restraining jig | tool 4, In this embodiment, it is comprised including the clamping means 4A which clamps the hollow shape member K, and the core 4B which prevents the hollow shape member K from being crushed.

  As shown in FIG. 6, the clamping means 4 </ b> A includes a pair of blocks 41 and 41 that sandwich the hollow member K, and a connecting member 42 that connects the blocks 41 and 41.

  The pair of blocks 41, 41 are opposed to each other with the end portion of the hollow shape member K sandwiched between them in contact with the outer side surface of the rotation cradle 1 (the side surface opposite to the side surface on the bending die 5 side). The hollow shape K is clamped so as not to slide. That is, the blocks 41 and 41 are attached to the hollow shape member K in a non-slidable state using frictional force generated between the blocks 41 and 41, and in this state, the lower support of the turntable 1 is supported. It is latched by the side surface of the part 12 and the upper support part 13 (refer FIG. 3). Note that a plurality of blade-like protrusions for increasing the friction coefficient are formed on the portion of the block 41 facing the hollow profile K.

  The connecting member 42 applies a force for sandwiching the hollow shape member K to the pair of blocks 41, 41, and is arranged above and below the hollow shape member K in this embodiment (see FIG. 3). . Although there is no restriction | limiting in the structure of the connection means 42, In this embodiment, it consists of the bolt penetrated by the blocks 41 and 41, and the nut screwed together by the axial part of the said bolt.

  The core 4B is formed by hollowing the contact members 43, 43 inserted into the internal space of the hollow shape member K, the wedge member 44 inserted between the contact members 43, 43, and the contact members 43, 43. A pressing member 45 that presses against the end face of the shape member K and a pulling means 46 that pulls the wedge member 44 toward the pressing member 45 are configured.

  The contact member 43 includes a support surface 43a that contacts the inner surface of the hollow shape member K, and an inclined surface 43b that is inclined with respect to the support surface 43a. A locking piece 43 c that is locked to the end surface of the hollow shape member K is formed at the end of the contact member 43. The pair of abutting members 43, 43 are arranged at an interval, and the separation distance between the inclined surfaces 43b, 43b increases toward the central portion (upper side in FIG. 6) of the hollow member K in the longitudinal direction. Become.

  The wedge member 44 is a member for pressing the contact members 43, 43 against the inner surface of the hollow shape member K, and includes a pair of tapered surfaces 44a, 44a that contact the inclined surfaces 43b, 43b of the contact members 43, 43. ing.

  The pressing member 45 is a member for preventing the contact members 43 and 43 from coming out of the hollow shape member K, and is pressed against the end surfaces of the contact members 43 and 43 exposed at the opening end surface of the hollow shape member K. Yes.

  The pulling means 46 includes a bolt 46 a inserted through an insertion hole formed in the wedge member 44 and an insertion hole formed in the holding member 45, and a shaft portion of the bolt 46 a between the wedge member 44 and the holding member 45. A presser nut 46b to be screwed, a tightening nut 46c to be screwed to the shaft part of the bolt 46a protruding from the presser member 45, and a gripping nut 46d to be screwed to the protruding end of the shaft part of the bolt 46a. I have. When the fastening nut 46c is tightened, the wedge member 44 moves to the pressing member 45 side, and the support surfaces 43a, 43a of the contact members 43, 43 abut against the inner surface of the hollow member K. When the core 4B is removed from the hollow member K, the fastening nut 46c is loosened and the bolt 46a is pushed into the hollow member K so that the contact members 43, 43 and the wedge member 44 are engaged. The combined state may be canceled.

  The bending die 5 shown in FIG. 3 translates in a direction perpendicular to the longitudinal direction of the hollow member K along a plane having the rotation center line P as a normal line, and follows a plane having the rotation center line P as a normal line. A direction pressing force is applied to the hollow member K. The configuration of the bending die 5 is not limited, but in this embodiment, an arm 51 connected to a pressing means (jack or the like) (not shown), a head 52 detachably attached to the tip of the arm 51, A pressing plate 53 fixed to the tip of the head 52 is provided. The pressing plate 53 is formed so that the surface on the hollow shape K side becomes the contact surface 5a described above.

  In order to manufacture the bending member K ′ using the bending apparatus configured as described above, first, the minimum separation distance e between the inner edge Ka of the hollow shape member K and the rotation center line P is expressed by Equation (1). The length of the hollow profile K is set so that the hollow profile K is installed between the rotary cradles 1 and 1 so that the center of the hollow profile K is located at the center of the rotation center lines P and P. Adjust the position of the direction. As shown in FIGS. 7A and 7B, the size of the minimum separation distance e can be adjusted by attaching a spacer 3 having an appropriate size to the rotary base 1. As shown in (c) and (d) of FIG. 5, the spacer 3 is not necessary when the expression (1) is satisfied in a state where the hollow shape member K is in contact with the receiving seat 11 of the turntable 1. . Incidentally, in FIGS. 7C and 7D, the inner edge Ka of the hollow member K and the rotation center line P coincide with each other (that is, e = 0).

  Subsequently, the restraining jig 4 is attached to each of both end portions of the hollow shape member K, and the end portion of the hollow shape member K is restrained to the turntable 1.

  Thereafter, the bending die 5 is moved toward the hollow shape member K, and when the apex of the contact surface 5a comes into contact with the inner edge Ka of the hollow shape member K (see FIG. 2A), the equation (17 When the bending die 5 is moved by the stroke amount y determined by (), the hollow profile K is bent while the rotation cradle 1 rotates about the rotation center line P, and the outer skin inside the bending A bending member K ′ having no irregularities and having no ground crack or the like on the outer skin of the bending is formed.

  Thus, according to the bending apparatus 100 which concerns on this embodiment, it becomes possible to implement | achieve the manufacturing method of the bending member which concerns on this embodiment easily.

  Note that, depending on the size of the minimum separation distance e, there may be a tensile bending, but since the restraining jig 4 is attached to the end of the hollow shape K protruding from the rotary cradle 1, the hollow shape K Thus, the end portion of the knives does not slip out of the rotary cradle 1, so that the accuracy of bending can be improved.

  In addition, since the spacer 3 can be attached to and detached from the rotating cradle 1, the inner edge Ka of the hollow profile K and the rotation of the rotating cradle 1 can be rotated simply by attaching or detaching the spacer 3 or replacing the spacer 3 with a different size. The minimum separation distance e with respect to the center line P can be easily adjusted.

  Further, since the pins 24 and 25 do not pass through the insertion space 1a of the rotation cradle 1 and face each other with the insertion space 1a of the rotation cradle 1 interposed therebetween, the spacer 3 is disposed between the pins 24 and 25. If the spacer 3 is omitted, the hollow member K can be disposed between the pins 24 and 25 (see FIG. 7C). That is, according to the bending apparatus 100 according to the present embodiment, the rotation center line P of the turntable 1 can be positioned behind the hollow profile K (on the outer edge Kb side). It is also possible to cross the hollow shape member K or to be positioned in front of the hollow shape member K (on the inner edge Ka side).

  In the present embodiment, the case where the hollow shape member K is pressed against the bending die 5 by moving the bending die 5 toward the hollow shape member K is illustrated, but the separation distance L between the rotation center lines P and P is exemplified. The hollow shape member K may be pressed against the bending die 5 by translationally moving the rotary cradle 1, 1 toward the bending die 5 while keeping the constant.

  Moreover, in this embodiment, although the manufacturing method of the bending member which provides the pressing force F of the direction along a horizontal surface to the hollow shape member K was illustrated, it is not the meaning which limits the application range of this invention. Although illustration is omitted, the present invention can also be applied to a method of manufacturing a bending member that applies a pressing force in a direction along a vertical plane to a hollow shape member.

  Further, in the present embodiment, the case where the cross-sectional shape of the hollow member K has a “day” shape is illustrated (see FIG. 5), but the cross-sectional shape of the hollow member K is not intended to be limited. Although illustration is omitted, the bending member manufacturing method and the bending apparatus described above can be applied to a hollow profile having a square cross section, a hollow profile having a circular cross section, and the like.

  Moreover, in the bending apparatus of this embodiment, although the case where the one bending die 5 which has a single circular arc surface was provided was illustrated, the bending apparatus which concerns on other embodiment shown to Fig.8 (a) is shown. As shown, two bending dies 5A and 5B may be provided. The two bending dies 5A and 5B are connected to each other, translate together toward the hollow member K, and are simultaneously pressed against the hollow member K (see FIG. 8B). The rotation cradle is the same as that of the above-described embodiment. According to such a bending apparatus, it is possible to perform R bending on the left and right of the hollow shape member K, and as a result, as shown in FIG. 8B, a bending member K ′ having curved portions on the left and right. Can be formed.

  When the specifications shown in Cases 1 to 3 in Table 1 are substituted into Equation (1), the minimum separation distance e is as shown in Table 2.

  In the range of Table 2 above, a hollow shape made of JIS standard 7000 series aluminum alloy (A7003-T5) and 6000 series aluminum alloy (A6N01-T6) is used, and the minimum value, 0, and maximum value of e for each case ( For example, in the case of No. 1, bending was performed at “−72.9”, “0”, “62.6”), but the depth of wrinkles generated in the outer skin should be controlled within 1 millimeter. It was confirmed that bending could be performed without causing breakage and buckling.

DESCRIPTION OF SYMBOLS 1 Rotation base 11 Base 2 Base 3 Spacer 4 Restraint jig 5 Bending type 5a Contact surface K Hollow shape material K 'Bending member Ka Bending inner edge P Rotation centerline

Claims (4)

Each end of the hollow profile to be bent is constrained to a turntable that is rotatably supported, and in this state, a bending force is applied to the hollow profile to provide a curved portion. A method for manufacturing a member, comprising:
The hollow profile is constrained to the rotary cradle so that the minimum separation distance e between the bent inner edge of the hollow profile and the rotation center line of the rotary cradle satisfies the following formula. A pressing force in a direction along a plane having the rotation center line as a normal line is applied to the hollow shape member while keeping a separation distance L between the rotation center line and the rotation center line of the other rotation receiving base constant. The manufacturing method of the bending member characterized by doing.
{S− (1 + a) × L / 2 + h × θ} / tan θ <e ≦ {S− (1−a / 5) × L / 2} / tan θ
here,
S: Reference length (mm) = r × θ + (L / 2−rsinθ) / cosθ
r: Bending radius (mm)
2θ: bending center angle (rad)
h: Girder height of hollow profile (mm)
a: Tensile breaking strain of the material constituting the hollow profile A pair of turntables rotatably supported;
A bending die pressed against a hollow shape to be bent;
A pressing force in a direction along a plane with the rotation center line of the rotation base as a normal line by pressing the hollow shape against the bending mold in a state where the end of the hollow shape is constrained to the rotation base. A bending apparatus for imparting to the hollow profile,
The said rotation receiving stand has an adjustment mechanism which can adjust the separation distance of the bending inner edge of the said hollow shape material, and the said rotation centerline, The bending processing apparatus characterized by the above-mentioned. The rotating cradle includes a seat for receiving a pressing force applied to the hollow shape member, and a spacer interposed between the hollow shape member and the seat,
The spacer is detachable from the rotation cradle,
The bending apparatus according to claim 2, wherein the restraining position of the hollow shape member is adjusted by attaching or detaching or replacing the spacer. Further comprising a restraining jig for restraining the end of the hollow shape member to the rotary cradle,
The rotating cradle has an insertion space into which the hollow profile can be inserted,
4. The bending apparatus according to claim 3, wherein the restraining jig is attached to the hollow shape member that protrudes to the side of the rotation receiving table through the insertion space of the rotation receiving table.

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