JP2016112568A - Bumper reinforcement bending device and bumper reinforcement bending method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bumper reinforcement bending device and a bending method capable of suppressing formation of recesses and reducing the amount of wastes.SOLUTION: The bending device 5 includes a bending die 61 having a processed surface k, an extrusion die 44 holding a bumper reinforcement B cooperatively with the bending die 61, a clamping mechanism 64 for fixing the bumper reinforcement B to the bending die 61, and servo mechanisms 51 58, 59, and 10 for controlling displacement of the bending die 61. The processed surface k has a first circular arc surface k1 formed on a start end side, and a second circular arc surface k2 formed on a tail end side. Further, the curvature radius of the first circular arc surface k is set smaller than that of the second circular arc surface k2. The servo mechanisms 51, 58, 59, and 10 rotate the bending die 61 around virtual rotary axes x and y different between during processing by the first circular arc surface k1 and during processing by the second circular arc surface k2.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a bumper reinforcement bending apparatus and a bumper reinforcement bending method, and in particular, bumper reinforcement bending capable of suppressing the generation of dents and reducing the amount of waste. The present invention relates to an apparatus and a bending method for bumper reinforcement.

Bumper reinforcement for automobiles is formed by performing spot forming on a seam after bending a belt-shaped high-tensile steel sheet into a predetermined tubular shape (pipe) by roll forming. The The bumper reinforcement is bent according to the shape of the bumper of the automobile to be installed.
Conventionally, stretch bender processing is known as a method of bending a bumper reinforcement (see Patent Document 1).
In stretch bender processing, bumper reinforcement is pressed by holding the bumper reinforcement against the mold while holding each end of the bumper reinforcement with a clamping device and applying tension to the bumper reinforcement with the clamping device. Is bent.

JP 2006-346683 A

However, in stretch bender processing, a tensile force is applied to the bumper reinforcement by the clamp device, so there is a risk that spot welding may come off, and it may be necessary to perform spot welding again after bending.
Also, since it is necessary to grip each end of the bumper reinforcement with a strong force by the clamping device, deformation occurs in each end of the bumper reinforcement, and it is necessary to cut and discard each deformed end, The amount of waste increases.
Furthermore, since both ends of the bumper reinforcement are gripped by the clamp device, the cored bar cannot be inserted into the bumper reinforcement, and a wave-like dent is generated inside the bent portion. There is a fear.
An object of the present invention is to provide a bumper reinforcement bending apparatus and a bumper reinforcement bending method capable of suppressing the occurrence of dents and reducing the amount of waste.

In order to solve the above problems, a bumper reinforcement bending apparatus according to a first aspect of the present invention includes a bending mold having a working surface corresponding to a target bending shape, and a bumper reinforcement in cooperation with the bending mold. A pressing die for clamping the bumper reinforcement to the bending die, and a servo mechanism for controlling the displacement of the bending die, wherein the processing surface is formed on a first end side. An arcuate surface and a second arcuate surface formed on the terminal side, the radius of curvature of the first arcuate surface is set smaller than the radius of curvature of the second arcuate surface, and the servo mechanism A virtual rotation axis that is different between the bending process using the first arc surface and the bending process using the second arc surface is set, and the bending die is rotated around the set virtual rotation axis. Characterized in that it is a capability.
In the bumper reinforcement bending apparatus according to the first aspect of the invention, no tension is applied to the bumper reinforcement by the clamp mechanism.
Accordingly, it is not necessary to grip each end portion of the bumper reinforcement with a strong force by the clamp mechanism, and deformation of each end portion of the bumper reinforcement can be suppressed.
Therefore, it is not necessary to cut and discard each end portion of the bumper reinforcement, and the amount of waste can be reduced.
In the bending apparatus for bumper reinforcement according to the first invention, a first arc surface formed on the start end side and a second arc surface formed on the end side are formed on the processing surface of the bending die. Has been. Further, the radius of curvature of the first arc surface is set smaller than the radius of curvature of the second arc surface.
As a result, the tip side portion (hereinafter referred to as “tip side machining portion”) of the R machining target portion in the bumper reinforcement is bent by the first circular arc surface having a small radius of curvature, and the R machining target. The portion on the center side with respect to the tip side processed portion (hereinafter referred to as “center side processed portion”) is bent by a second arc surface having a large curvature radius. Here, the “R processing target portion” refers to a portion of the bumper reinforcement that is to be bent.
In particular, in the bumper reinforcement bending apparatus according to the first aspect of the invention, the servo mechanism sets and sets different virtual rotation axes when bending with the first arc surface and when bending with the second arc surface. The bending mold is rotated around the virtual axis of rotation.
Thus, when bending the tip side processed portion, the bending die is rotated around the virtual rotation axis related to the small turning radius, while when bending the center side processed portion, the virtual rotation axis related to the large turning radius. The bending die can be rotated around the center.
Specifically, at the time of bending with the first arc surface, an imaginary rotation axis is set at the center of curvature of the first arc surface, and bending is performed on the tip side processed portion, while on the other hand, with the second arc surface At the time of bending, an imaginary rotation axis can be set at the center of curvature of the second arc surface, and the center side processed portion can be bent.
Therefore, for the tip side processed part where the spring back is strong and the dent is difficult to occur, by applying a bending process with a small bending radius, the spring back can be suppressed without generating a dent. The accuracy with respect to the bending R to be performed can be improved. On the other hand, for the center side processed part where spring back is weak and dents are likely to occur, bending is suppressed with a large bending radius, thereby suppressing the occurrence of dents without reducing the accuracy of the target bending R. can do.
As described above, according to the bumper reinforcement bending apparatus according to the first aspect of the present invention, it is possible to suppress the occurrence of dents and reduce the amount of waste.

The bumper reinforcement bending apparatus according to the second invention is the bumper reinforcement bending apparatus according to the first invention, wherein the neutral axis is the thickness direction of the bumper reinforcement at the time of bending by the first arc surface. The neutral axis is set inward from the center in the thickness direction of the bumper reinforcement when bending by the second arcuate surface.
In the bending apparatus for bumper reinforcement according to the second aspect of the invention, the neutral axis (neutral surface) is set outside the center in the thickness direction of the tip side machining portion when bending the tip side machining portion by the first arc surface. As a result, the range in which the compressive stress acts in the thickness direction of the tip side processed portion becomes wider than the range in which the tensile stress acts. Thereby, the spring back is suppressed, and the accuracy with respect to the target bending R can be improved. Here, the “neutral axis (neutral plane)” refers to a place (plane) where stress (tensile stress and compressive stress) does not act when bending is performed.
On the other hand, at the time of bending with respect to the center side processed portion by the second arc surface, the neutral axis (neutral surface) is set inward from the center in the thickness direction of the tip side processed portion, so that in the thickness direction of the center side processed portion The range in which the compressive stress acts is narrower than the range in which the tensile stress acts. Thereby, generation | occurrence | production of a dent can be suppressed.

The bumper reinforcement bending apparatus according to a third aspect of the invention is the bumper reinforcement bending apparatus according to the first or second aspect of the invention, wherein the servo mechanism is arranged according to a cross-sectional shape of the bumper reinforcement. It is possible to tilt the virtual rotation axis.
In the bumper reinforcement bending apparatus according to the third aspect of the invention, it is possible to cause twisting in the bent portion by inclining the virtual rotation axis according to the cross-sectional shape of the bumper reinforcement. Can be suppressed.

A bumper reinforcement bending apparatus according to a fourth aspect of the invention is the bumper reinforcement bending apparatus according to any one of the first to third aspects, wherein the core is inserted into the hollow portion of the bumper reinforcement. A second servo mechanism for controlling the withdrawal of the core metal inserted in the hollow portion, the core metal is formed by connecting a plurality of core metal pieces, and the second servo mechanism is The cored bar inserted in the hollow portion is pulled out in synchronization with the displacement of the bending die by the servo mechanism, and compared with the bending process by the first arc surface when bending by the second arc surface. Then, the core metal is pulled out at a high speed.
In the bumper reinforcement bending apparatus according to the fourth aspect of the invention, the cored bar inserted into the hollow portion is pulled out in synchronization with the displacement of the bending die by the servo mechanism.
As a result, it is possible to bend the bumper reinforcement with the bending die while applying a tensile force to the bumper reinforcement with the core metal, and to suppress the occurrence of the dent.
In particular, in the bending apparatus for bumper reinforcement according to the fourth aspect of the invention, the core metal is drawn at a higher speed when bending by the second arc surface than when bending by the first arc surface.
As a result, when bending the center side processed part, compared to when bending the tip side processed part, bending is performed while applying a strong tensile force, and the generation of dents can be suppressed more reliably. It becomes.

A bumper reinforcement bending apparatus according to a fifth aspect of the invention is the bumper reinforcement bending apparatus according to any one of the first to fourth aspects, wherein the bumper reinforcement is clamped by the clamp mechanism. Clamp position changing means that can be changed is provided.
In the bumper reinforcement bending apparatus according to the fifth invention, the bending moment applied to the bumper reinforcement can be changed by changing the clamp position of the bumper reinforcement by the clamp mechanism.

A bumper reinforcement bending method according to a sixth aspect of the present invention includes a clamp mechanism that fixes the bumper reinforcement to a bending die having a working surface corresponding to a target bending shape, and displaces the bending die. A bumper reinforcement bending method for bending the bumper reinforcement by a first step of bending the bumper reinforcement by a first arc surface formed on a start end side of the processed surface; A second step of bending the bumper reinforcement with a second arc surface formed on the terminal side of the processed surface, and the radius of curvature of the first arc surface is the second arc surface It is set to be smaller than the radius of curvature, and a different virtual axis of rotation is set in the first step and the second step. Is characterized by rotating the bending tool about an axis of rotation of the set the virtual.
In the bumper reinforcement bending method according to the sixth aspect of the invention, the clamping mechanism does not apply a tensile force to the bumper reinforcement.
Accordingly, it is not necessary to grip each end portion of the bumper reinforcement with a strong force by the clamp mechanism, and deformation of each end portion of the bumper reinforcement can be suppressed.
Therefore, each end of the bumper reinforcement is not cut and discarded, and the amount of waste can be reduced.
In the bumper reinforcement bending method according to the sixth aspect of the present invention, a first arc surface formed on the start end side and a second arc surface formed on the end side are formed on the processing surface of the bending die. Has been. Further, the radius of curvature of the first arc surface is set smaller than the radius of curvature of the second arc surface.
As a result, the tip side processed portion is bent by the first arc surface having a small curvature radius, while the center side processed portion is bent by the second arc surface having a large curvature radius.
In particular, in the bumper reinforcement bending method according to the sixth aspect of the invention, different virtual rotation axes are set when bending with the first arc surface and when bending with the second arc surface. The bending mold is rotated around the rotation axis.
As a result, the bending die is rotated around the virtual rotation axis related to the small turning radius when bending the tip side processed portion, while the virtual rotating shaft related to the large turning radius is bent when bending the center side processed portion. The bending mold is rotated around the center.
Specifically, at the time of bending by the first arc surface, a virtual rotation axis is set at the center of curvature of the first arc surface, and the distal end side processed portion is bent, while the second arc surface At the time of bending, a virtual rotation axis is set at the center of curvature of the second arcuate surface, and the center-side processed portion is bent.
Therefore, for the tip side processed part where the spring back is strong and the dent is difficult to occur, by applying a bending process with a small bending radius, the spring back can be suppressed without generating a dent. The accuracy with respect to the bending R to be performed can be improved. On the other hand, for the center side processed part where spring back is weak and dents are likely to occur, bending is suppressed with a large bending radius, thereby suppressing the occurrence of dents without reducing the accuracy of the target bending R. can do.
As described above, according to the bumper reinforcement bending method according to the sixth aspect of the invention, it is possible to suppress the generation of dents and reduce the amount of waste.

The bumper reinforcement bending method according to the seventh invention is the bumper reinforcement bending method according to the sixth invention, wherein, in the first step, the neutral axis is outside the center in the thickness direction of the bumper reinforcement. In the second step, the neutral axis is set on the inner side of the center in the thickness direction of the bumper reinforcement.
In the bending method for bumper reinforcement according to the seventh aspect of the invention, the neutral axis (neutral surface) is set outside the center in the thickness direction of the tip side machining portion when bending the tip side machining portion by the first arc surface. As a result, the range in which the compressive stress acts in the thickness direction of the tip side processed portion becomes wider than the range in which the tensile stress acts. Thereby, the spring back is suppressed, and the accuracy with respect to the target bending R can be improved.
On the other hand, at the time of bending with respect to the center side processed portion by the second arc surface, the neutral axis (neutral surface) is set inward from the center in the thickness direction of the tip side processed portion, so that in the thickness direction of the center side processed portion The range in which the compressive stress acts is narrower than the range in which the tensile stress acts. Thereby, generation | occurrence | production of a dent can be suppressed.

The bumper reinforcement bending method according to the eighth invention is the bumper reinforcement bending method according to the sixth or seventh invention, in at least one of the first step and the second step, The virtual rotation axis is inclined according to the cross-sectional shape of the bumper reinforcement.
In the bumper reinforcement bending method according to the eighth aspect of the present invention, by twisting the virtual rotation axis according to the cross-sectional shape of the bumper reinforcement, the twisted portion is generated in the bent portion. Can be suppressed.

The bumper reinforcement bending method according to the ninth invention is the bumper reinforcement bending method according to any one of the sixth to eighth inventions, in each of the first step and the second step. The core metal inserted in the hollow portion of the bumper reinforcement is pulled out in synchronization with the displacement of the bending die, and the core metal is formed by connecting a plurality of core metal pieces. In the second step, The core metal is pulled out at a higher speed than in the first step.
In the bumper reinforcement bending method according to the ninth aspect of the invention, the cored bar inserted into the hollow portion is pulled out in synchronization with the displacement of the bending die.
As a result, it is possible to bend the bumper reinforcement with the bending die while applying a tensile force to the bumper reinforcement with the core metal, and to suppress the occurrence of the dent.
In particular, in the bumper reinforcement bending method according to the ninth aspect of the invention, the cored bar is drawn at a higher speed when bending by the second arc surface than when bending by the first arc surface.
As a result, when bending the center side processed part, compared to when bending the tip side processed part, bending is performed while applying a strong tensile force, and the generation of dents can be suppressed more reliably. It becomes.

The bumper reinforcement bending method according to a tenth invention is the bumper reinforcement bending method according to any one of the sixth to ninth inventions, wherein the first step and the second step are: The clamp position of the bumper reinforcement by the clamp mechanism is changed.
In the bumper reinforcement bending method according to the tenth invention, the bending added to the bumper reinforcement by changing the clamp position of the bumper reinforcement by the clamp mechanism in the first step and the second step. It is possible to change the moment.

  According to the bumper reinforcement bending apparatus and the bumper reinforcement bending method according to the present invention, it is possible to suppress the generation of dents and to reduce the amount of waste.

It is a figure which shows the structure of bumper reinforcement B. 2 is a plan view showing a configuration of a bending line 1. FIG. It is a front view of the bending apparatus. It is a side view of the bending apparatus 5. FIG. It is sectional drawing of the center lower mold | type 32 and the pressing mold 44. FIG. 3 is a front view of a bending die 61. FIG. FIG. 4 is a cross-sectional view of a holding die 44 and a bending die 61. It is a figure which shows the structure of the metal core 67. FIG. 3 is a block diagram illustrating a configuration of a bending control unit 10. FIG. It is a figure which shows the state of the bending apparatus 5 before the start of a bending process. It is a figure which shows the state of the bending apparatus 5 in F of the 1st process of a bending process. It is a figure which shows the state of the bending process apparatus 5 in the 2nd process of a bending process. It is a figure which shows the state of the bending apparatus 5 in the 3rd process of a bending process. It is a figure which shows the state of the bending apparatus 5 in the 4th process of a bending process. It is a figure which shows the state of the bending apparatus 5 in the 5th process of a bending process. It is a figure which shows the state of the bending die 61 at the time of the start of the 5th process of a bending process. It is a figure which shows the state of the bending die 61 at the time of completion | finish of the 5th process of a bending process. It is a figure which shows the state of the bending apparatus 5 in the 6th process of a bending process. It is a figure which shows the state of the bending die 61 at the time of completion | finish of the 6th process of a bending process. It is a figure explaining the setting method of a bending amount. It is a figure which shows the state of the bending apparatus 5 in the 6th process of the bending process which concerns on a modification. It is a figure which shows the state of the bending apparatus 5 in the 7th process of a bending process. It is a figure which shows the state of the bending apparatus 5 in the 8th process of a bending process. It is a figure which shows the state of the bending apparatus 5 after completion | finish of a bending process.

Hereinafter, a bending line 1 (bending apparatus 5) according to an embodiment of the present invention will be described with reference to the drawings.
(Composition of bumper reinforcement B)
First, the bumper reinforcement B that is bent by the bending line 1 (bending apparatus 5) will be described.
FIG. 1 is a diagram illustrating a configuration of bumper reinforcement B. In FIG. 1, the bumper reinforcement B after being bent by the bending line 1 is shown. 1A is a plan view of the bumper reinforcement B, FIG. 1B is a front view of the bumper reinforcement B, and FIG. 1C is a cross-sectional view of the bumper reinforcement B. It is a perspective view shown.
The bumper reinforcement B is formed of a high-tensile steel plate. In particular, the bumper reinforcement B according to the present embodiment is formed from a high-tensile steel plate having a tensile strength of 1200 [Mpa] or more.
The bumper reinforcement B is formed by subjecting a belt-like high-tensile steel plate to roll forming, bending it into a predetermined tubular shape (pipe shape), and then spot welding the joint portion.

As shown in FIG. 1, the bumper reinforcement B according to this embodiment includes a first tubular portion p1, a second tubular portion p2, and a connecting portion c that connects the first tubular portion p1 and the second tubular portion p2. And have.
As shown in FIG.1 (c), the 1st tubular part p1 and the 2nd tubular part p2 are each formed in the tubular (pipe shape) which has the hollow part h. In the bumper reinforcement B, a joint portion s is disposed at the connecting portion c, and spot welding is performed at the joint portion s.
The bumper reinforcement B before being bent by the bending line 1 (bending apparatus 5) extends substantially linearly (not shown). The bumper reinforcement B is bent according to the shape of the bumper of the automobile to be installed. At this time, in the bumper reinforcement B, a portion where the bending process is not performed (hereinafter referred to as “R processing non-target part b1”) and a part where the bending process is performed (hereinafter referred to as “R processing target part b2”). ) And are set.

Specifically, in the bumper reinforcement B, an R processing target portion b2 is set at each end portion in the longitudinal direction (the left-right direction shown in FIGS. 1A and 1B), and the central portion in the longitudinal direction. In (between both R machining target parts b2), the R machining non-target part b1 is set.
Then, the bending process line 1 (bending apparatus 5) performs bending on each R processing target part b2 in the bumper reinforcement B. Thereby, as shown to Fig.1 (a), bumper reinforcement B becomes a shape where each edge part (each R process object part b2) curved.

(Configuration of bending line 1)
Next, the configuration of the bending line 1 will be described.
FIG. 2 is a plan view showing the configuration of the bending line 1.
As shown in FIG. 2, the bending line 1 includes a material mounting table 2, 3, a material inspection / material processing unit 4, a bending device 5, a product inspection device 6, a product mounting table 7, and material loading. A device 8, a product carry-out device 9, and a line control device (not shown) are provided.
On each material mounting table 2, 3, a material pallet that houses a bumper reinforcement B (a linear bumper reinforcement B) before being bent is placed.
The material inspection / material processing unit 4 includes a material inspection device 4a and a material processing device 4b.
For the bumper reinforcement B installed at a predetermined processing position, the material inspection apparatus 4a has a cross-sectional dimension (vertical dimension shown in FIG. 1A), a warp amount, a deformation of a shape with respect to a preset reference shape, and the like. And the measurement result is output to a line control device described later.

The material processing apparatus 4b performs a refinement | purification process with respect to each edge part of the bumper reinforcement B installed in the predetermined process position. Specifically, the material processing apparatus 4b includes a shape correcting device and a cutting device. The shape correction device corrects deformation (crushing) generated at each end of the bumper reinforcement B by press-fitting a wedge-shaped member into the hollow portion h of each tubular portion p1, p2 of the bumper reinforcement B. To do. The cutting device cuts burrs generated at each end of the bumper reinforcement B by a cutting jig.
The bending apparatus 5 performs a bending process on the bumper reinforcement B installed on the center lower mold 32 described later. A specific configuration of the bending apparatus 5 will be described later.
The product inspection device 6 measures the bending R (bending radius of the bent portion), the state of occurrence of the dent, and the like for the bumper reinforcement B installed at a predetermined inspection position, and performs line control to describe the measurement result later. Output to the device.
A product pallet for accommodating the bumper reinforcement B subjected to the bending process is placed on the product mounting table 7.

The material carry-in device 8 includes an arm portion 8b having a gripping device 8a capable of gripping the bumper reinforcement B. The arm portion 8b is configured to be able to rotate about a rotation axis extending in the vertical direction, to move the gripping device 8a up and down along the vertical direction, and to expand and contract. The material carry-in device 8 holds the bumper reinforcement B accommodated in the material pallet placed on each material placing table 2, 3 and is installed at a predetermined processing position of the material inspection / material processing unit 4. It is possible to do. Further, the material carry-in device 8 can hold the bumper reinforcement B installed at a predetermined processing position of the material inspection / material processing unit 4 and can be installed on the lower central mold 32 of the bending device 5. It has become.
The product carry-out device 9 includes an arm portion 9b having a gripping device 9a capable of gripping the bumper reinforcement B. The arm portion 9b is configured to be able to rotate about a rotation axis extending in the vertical direction, to raise and lower the gripping device 9a along the vertical direction, and to extend and contract. And the product carrying-out apparatus 9 can hold | maintain the bumper reinforcement B installed on the center lower mold | type 32 of the bending apparatus 5, and can be installed in the predetermined inspection position of the product inspection apparatus 6. FIG. . Further, the product carry-out device 9 can hold the bumper reinforcement B installed at a predetermined inspection position of the product inspection device 6 and accommodate it in the product pallet placed on the product placement table 7. ing.
The line control device controls each of the material inspection / material processing unit 4, the bending device 5, the product inspection device 6, the material carry-in device 8, and the product carry-out device 9 according to a predetermined control program. In particular, the line control apparatus includes a bending process control unit 10 (see FIG. 9) for controlling the bending apparatus 5. A specific configuration of the bending control unit 10 will be described later.

(Configuration of bending apparatus 5)
Next, the configuration of the bending apparatus 5 will be described.
FIG. 3 is a front view of the bending apparatus 5. FIG. 4 is a side view of the bending apparatus 5. FIG. 5 is a cross-sectional view of the central lower mold 32 and the pressing mold 44. FIG. 6 is a front view of the bending die 61. FIG. 7 is a cross-sectional view of the pressing die 44 and the bending die 61. FIG. 8 is a view showing the configuration of the cored bar 67. 8A is a plan view of the cored bar 67, and FIG. 8B is a front view of the cored bar 67. FIG.
As shown in FIGS. 3 and 4, the bending apparatus 5 includes a housing 20, a lower mold unit 30, a pressing mold unit 40, and a pair of bending mold units 50.
The housing 20 is formed in a box shape whose front and back are open.
The lower mold unit 30 includes a pedestal 31 fixed to the bottom surface of the housing 20 and a central lower mold 32 supported by the pedestal 31 at a predetermined height.
As shown in FIG. 5, the center lower mold 32 can mount the bumper reinforcement B so that both tubular portions p <b> 1 and p <b> 2 are aligned along the depth direction (the left-right direction shown in FIG. 4). It is formed as follows. Specifically, the central lower mold 32 has a substantially convex cross section that is orthogonal to the left-right direction (the left-right direction shown in FIG. 3). Thus, the lower surface of the bumper reinforcement B can be supported by the upper surface of the central lower mold 32.

The holding die unit 40 includes a holding die lifting / lowering servo drive device 41 and a pressure device 42 fixed to the top surface of the housing 20, a pressure die 43 lifted and lowered by the holding die lifting / lowering servo drive device 41, and a pressure die 43. And a holding die 44 attached to the.
The press-type lifting / lowering servo drive device 41 is constituted by a servo cylinder. Specifically, the press-type lifting / lowering servo drive device 41 includes a servo motor 41a (see FIG. 9) and a cylinder rod 41b. In the press-type lifting / lowering servo drive device 41, the cylinder rod 41b can be expanded and contracted by converting the rotational motion of the servo motor 41a into the linear movement of the cylinder rod 41b via a ball screw. (The same applies to servo drive devices 51, 58, 59, 62, and 66 described later). In the presser type lifting / lowering servo drive device 41, the cylinder rod 41b can be expanded and contracted along the vertical direction (the vertical direction shown in FIG. 3).
The pressurizing device 42 is constituted by a hydraulic cylinder. Specifically, in the pressurizing device 42, the cylinder rod 42a can be expanded and contracted along the vertical direction by controlling the hydraulic pressure. In the present embodiment, the pressurizing device 42 assists the pressure die 43 to be pushed downward (pressurized) by the presser type lifting / lowering servo drive device 41.
The pressure die 43 is fixed to the lower end portion of the cylinder rod 41b of the press-type lifting / lowering servo drive device 41 and the lower end portion of the cylinder rod 42a of the pressurizing device 42, respectively. A product pressing device 45 is arranged on the lower surface of the pressure die 43. The product pressing device 45 can extend and contract the product pressing portion in the vertical direction.

The holding die 44 is installed on the lower surface of the pressure die 43. The holding die 44 clamps the bumper reinforcement B in cooperation with the central lower die 32 and a bending die 61 described later. That is, the pressing die 44 is formed so as to be able to press (support) the upper surface of the bumper reinforcement B installed on the central lower die 32. Specifically, as shown in FIG. 5, the holding die 44 has a substantially concave shape in cross section perpendicular to the left-right direction (left-right direction shown in FIG. 3). As a result, the upper surface of the bumper reinforcement B can be pressed by the lower surface of the pressing die 44. The substantially lower entire area of the bumper reinforcement B is supported by the central lower mold 32 and the pressing mold 44.
In the present embodiment, the presser mold 44 includes a pair of presser mold pieces 44a and 44b. Each pressing mold piece 44a, 44b can be moved along the left-right direction by the moving device 46.

The pair of bending die units 50 are installed in opposite directions in the left-right direction. As a result, one bending die unit 50 of the pair of bending die units 50 bends one of the ends of the bumper reinforcement B and the other of the pair of bending die units 50. The bending mold unit 50 performs bending on the other end of both ends of the bumper reinforcement B.
Each bending die unit 50 includes a pair of base movement servo drive devices 51 fixed to the bottom surface of the housing 20 and a movement unit 52 moved in the left-right direction by the pair of base movement servo drive devices 51. I have.
The pair of base movement servo drive devices 51 are juxtaposed along the depth direction. In FIG. 3, only the base-side servo drive device 51 on the front side of the pair of base-movement servo drive devices 51 is shown. Each base moving servo drive device 51 is constituted by a servo cylinder. Specifically, each base moving servo drive device 51 includes a servo motor 51a (see FIG. 9) and a cylinder rod 51b. In each base moving servo drive device 51, the cylinder rod 51b can be expanded and contracted along the left-right direction.

The moving unit 52 includes a base mechanism part 53, a mold mechanism part 54 and a clamp mechanism part 55 attached to the base mechanism part 53, and a core metal mechanism part 56 attached to the mold mechanism part 54. Yes.
The base mechanism unit 53 includes a moving base 57, a pair of rotary shaft lifting / lowering servo drive devices 58 fixed to the moving base 57, and a rotary shaft T lifted / lowered by the pair of rotary shaft lifting / lowering servo drive devices 58. I have.
The moving base 57 is fixed to the tip of the cylinder rod 51 b of each base moving servo drive device 51. Accordingly, the moving base 57 is moved along the left-right direction in accordance with the expansion and contraction of the cylinder rod 51b of each base-moving servo drive device 51. Further, in each bending die unit 50, the moving base 57 can be rotated along the horizontal plane by changing the expansion / contraction amount of the cylinder rod 51b by the both-base moving servo drive devices 51. Thereby, the direction in which a virtual rotation axis x, y (rotation axis T), which will be described later, extends is changed (the position of one end and the position of the other end of the virtual rotation axes x, y in the left-right direction). Can be shifted).
As shown in FIG. 4, the pair of rotary shaft raising / lowering servo drive devices 58 are arranged in parallel along the depth direction. In FIG. 3, only the front rotary shaft raising / lowering servo drive device 58 of the pair of rotary shaft raising / lowering servo drive devices 58 is shown. Each rotary shaft raising / lowering servo drive device 58 is constituted by a servo cylinder. Specifically, each rotary shaft lifting / lowering servo drive device 58 includes a servo motor 58a (see FIG. 9) and a cylinder rod 58b. In each rotary shaft lifting / lowering servo drive device 58, the cylinder rod 58b can be expanded and contracted along the vertical direction.

  The rotation axis T is formed in a cylindrical shape. Each end of the rotary shaft T is fixed to a cylinder rod 58b of each rotary shaft lifting / lowering servo drive device 58. As a result, the rotary shaft T is moved along the vertical direction in accordance with the expansion and contraction of the cylinder rod 58b of each rotary shaft lifting servo drive device 58. Further, in each bending mold unit 50, the virtual rotation axes x and y (rotation axis T) are inclined with respect to the horizontal direction by making the expansion / contraction amount of the cylinder rod 58 b different by the servo drive devices 58 for raising and lowering the rotation axes. (The positions of the end portions on one side and the end portions on the other side of the virtual rotation axes x and y can be shifted in the vertical direction).

The mold mechanism unit 54 includes a bending mold rotating servo driving device 59 fixed to the moving base 57, a rotating base 60 rotated by the bending mold rotating servo driving device 59, and a bending mold fixed to the rotating base 60. 61.
The bending type rotation servo drive device 59 is constituted by a servo cylinder. Specifically, the bending-type rotating servo drive device 59 includes a servo motor 59a (see FIG. 9) and a cylinder rod 59b. In the bending-type rotating servo drive device 59, the cylinder rod 59b can be expanded and contracted along.
The rotation base 60 includes a first base portion 60a formed in a substantially triangular plate shape when viewed from the front, and a second base portion 60b formed in a substantially rectangular plate shape when viewed from the front surface. Of the three corner portions of the first base portion 60a, the first corner portion is provided with a bearing hole H1 through which the rotation shaft T is inserted, and the second corner portion is continuously provided with the second base portion 60b. The bending die 61 is fixed to the third corner.
The rotation base 60 is rotatably arranged around the rotation shaft T (bearing hole H1) by inserting the rotation shaft T through the bearing hole H1. Further, the tip end portion of the cylinder rod 59b of the bending type rotation servo drive device 59 is fixed at a position eccentric to the bearing hole H1 in the rotation base 60. As a result, the rotation base 60 is rotated about the rotation axis T according to the expansion and contraction of the cylinder rod 59b of the bending-type rotation servo drive device 59.

As shown in FIG. 6, the bending die 61 is formed in a substantially wedge shape when viewed from the front. A processing surface k for bending the bumper reinforcement B is formed on the outer peripheral surface of the bending die 61. The processing surface k extends in a substantially arc shape corresponding to a target bending shape when viewed from the front. Further, as shown in FIG. 7, the processing surface k (bending die 61) has a substantially convex shape in a cross section orthogonal to the left-right direction. Thus, the lower surface of the bumper reinforcement B can be supported by the machining surface k. The bending die 61 and the holding die 44 support substantially the entire area in the outer circumferential direction of the bumper reinforcement B (a position where bending is performed by the bending die 61).
In particular, the machining surface k includes a first arc surface k1, a second arc surface k2, and a clamp surface k3. The clamp surface k3 is formed on the most end side among the first arc surface k1, the second arc surface k2, and the clamp surface k3. The first arc surface k1 is formed on the terminal end side with respect to the clamp surface k3 and on the start end side with respect to the second arc surface k2. The second arc surface k2 is formed at the most end side among the first arc surface k1, the second arc surface k2, and the clamp surface k3.
Here, the “starting side” refers to the side where the bumper reinforcement B is first bent in a time series, and the “terminal side” refers to the bumper reinforcement in a time series. The side where B is bent. The first arc surface k1, the second arc surface k2, and the clamp surface are formed in a series.

The tip of the bumper reinforcement B is fixed to the clamp surface k3 by a clamp device 64 described later at the start of bending. The first arcuate surface k1 bends a predetermined portion (hereinafter referred to as “tip-side processed portion”) on the tip side of the R-processing target portion in the bumper reinforcement B. The second arcuate surface k2 is subjected to a bending process on a predetermined part on the center side (hereinafter referred to as “center side processing part”) with respect to the tip side processing part among the R processing target parts in the bumper reinforcement B.
The curvature radius R1 of the first arc surface k1 is set smaller than the curvature radius R2 of the second arc surface k2. Specifically, the curvature radius R1 of the first arc surface k1 is calculated by the following equation (1), and the curvature radius R2 of the second arc surface k2 is calculated by the following equation (2).
R1 [mm] = RB [mm] × m [%] / 100 (1)
R2 [mm] = RB [mm] × n [%] / 100 (2)
Here, “RB” is a target value of the bending R (inner side R) of the R processing target part b2 of the bumper reinforcement B. In addition, “m” and “n” are set to arbitrary numerical values so that “m <n”. In this embodiment, m≈60 is set and n≈70 is set.
Further, the center angle α of the first arc surface k1 is calculated by the following equation (3), and the center angle β of the second arc surface k2 is calculated by the following equation (4).
α [°] = (360 [°] × t [mm] × σ) / (2 × R1 [mm] × π) (3)
β [°] = (360 [°] × (Lr [mm] − (t [mm] × σ))) / (2 × R2 [mm] × π) (4)
Here, “t” is the cross-sectional dimension (vertical dimension) of the bumper reinforcement B. “Σ” is an arbitrarily set constant, and in the present embodiment, a predetermined numerical value that falls within the range of 2.0 to 3.0 is set. Further, “Lr” is a dimension in the longitudinal direction of the R processing target portion b2 of the bumper reinforcement B.
In this embodiment, R1≈550 [mm], R2≈600 [mm], α≈10 [°], and β≈25 [°] are set.

The clamp mechanism portion 55 includes a clamp position movement servo drive device 62 fixed to the second base portion 60 b of the rotation base 60, a columnar base 63 rotated by the clamp position movement servo drive device 62, and the columnar base 63. A fixed clamping device 64.
The clamp position moving servo drive device 62 is constituted by a servo cylinder. Specifically, the clamp position moving servo drive device 62 includes a servo motor 62a (see FIG. 9) and a cylinder rod 62b. In the clamp position moving servo drive device 62, the cylinder rod 62b can be expanded and contracted along a predetermined direction.
The columnar base 63 includes a pair of leg portions 63a. Each leg portion 63a is formed in a plate shape having a predetermined length. A bearing hole H2 through which the rotation shaft T is inserted is provided at the lower end of each leg portion 63a.
The columnar base 63 is rotatably arranged around the rotation shaft T (bearing hole H1) by inserting the rotation shaft T through the bearing hole H2 of each leg portion 63a. Here, the rotation base 60 and the columnar base 63 are rotatably supported by the rotation shaft T in a state where the rotation base 60 is sandwiched between both leg portions 63 a of the columnar base 63. Further, the tip of the cylinder rod 62 b of the clamp position moving servo drive device 62 is fixed to the upper end of the columnar base 63. As a result, the columnar base 63 is rotated about the rotation axis T in accordance with the expansion and contraction of the cylinder rod 62b of the servo drive device 62 for moving the clamp position.

  The clamp device 64 is installed at the upper end of the columnar base 63. The clamp device 64 includes a clamp member 64a that can be moved up and down. The clamp device 64 can fix the bumper reinforcement B to the processing surface k of the bending die 61 by lowering the clamp member 64a. At this time, in each bending die unit 50, the clamp position by the clamp device 64 can be changed in accordance with the expansion and contraction of the cylinder rod 62b of the clamp position moving servo drive device 62.

The cored bar mechanism 56 includes a pair of cored bar accommodating parts 65 fixed to the upper surface of the first base part 60a of the rotating base 60 and a cored bar insertion / extraction servo drive fixed to the second base part 60b of the rotating base 60. A device 66 and a pair of metal cores 67 moved by a core metal insertion / extraction servo drive device 66 are provided.
The core metal insertion / extraction servo drive device 66 is constituted by a servo cylinder. Specifically, the core drive servo driving device 66 includes a servo motor 66a (see FIG. 9) and a cylinder rod 66b. In the core metal insertion / extraction servo drive device 66, the cylinder rod 66b can be expanded and contracted along a predetermined direction.
Each cored bar accommodating portion 65 is formed in a cylindrical shape. And a pair of core metal accommodating part 65 is arranged in parallel along the depth direction. In FIG. 3, only the front metal core housing part 65 of the pair of metal core housing parts 65 is shown. A single cored bar 67 is accommodated in each cored bar accommodating portion 65.
As shown in FIG. 8, each cored bar 67 is configured by connecting a plurality of cored bar pieces 67a. Specifically, the two core metal pieces 67a adjacent to each other are connected to each other via the rotation shaft 67b and can rotate with respect to each other about the rotation shaft 67b. A distal end portion of the cylinder rod 66b of the core metal insertion / removal servo drive device 66 is fixed to the base end portion of each core metal 67. Each core metal 67 is a hollow portion h of each tubular portion p1, p2 of the bumper reinforcement B fixed to the bending die 61 by the clamp device 64 according to the expansion and contraction of the cylinder rod 66b of the servo drive device 66 for core metal insertion / extraction. Inserted into or extracted from.

(Configuration of bending processing control unit 10)
Next, the configuration of the bending control unit 10 will be described.
FIG. 9 is a block diagram illustrating a configuration of the bending control unit 10.
As shown in FIG. 9, the bending process control unit 10 corresponds to the input touch panel 11, the centralized control sequencer 12, the motion control (controller) 13, and the servo motors 41a, 51a, 58a, 59a, 62a, and 66a. Servo amplifier A.
The input touch panel 11 can input the type of product (bumper reinforcement B after bending).
The centralized control sequencer 12 outputs a control signal to the motion control in accordance with a control program corresponding to the product type input from the input touch panel 11.
The motion control 13 outputs a command signal to each servo amplifier A in accordance with the control signal input from the central control sequencer 12.
Each servo amplifier A supplies power to the corresponding servo motor in accordance with the command signal input from the motion control 13. Thereby, rotation of the servo motor corresponding to each servo amplifier A is started.
In particular, each servo motor 41a, 51a, 58a, 59a, 62a, 66a includes a detector (encoder). Each detector outputs a feedback signal corresponding to the rotation state of the servo motor to the corresponding servo amplifier A during rotation of the corresponding servo motor. Each servo amplifier A supplies power to the corresponding servo motor so that there is no error between the command signal input from the motion control 13 and the feedback signal input from the detector.

(Operation of bending line 1)
Next, the operation of the bending line 1 will be described.
FIG. 10 is a diagram illustrating a state of the bending apparatus 5 before the start of the bending process. FIG. 11 is a diagram illustrating a state of the bending apparatus 5 in the first step of the bending process. FIG. 12 is a diagram illustrating a state of the bending apparatus 5 in the second step of the bending process. FIG. 13 is a diagram illustrating a state of the bending apparatus 5 in the third step of the bending process. FIG. 14 is a diagram illustrating a state of the bending apparatus 5 in the fourth step of the bending process.
FIG. 15 is a diagram illustrating a state of the bending apparatus 5 in the fifth step of the bending process. FIG. 16 is a diagram showing the state of the bending die 61 at the start of the fifth step of the bending process. FIG. 17 is a diagram showing a state of the bending die 61 at the end of the fifth step of the bending process. FIG. 18 is a diagram illustrating a state of the bending apparatus 5 in the sixth step of the bending process. FIG. 19 is a diagram showing a state of the bending die 61 at the end of the sixth step of the bending process. FIG. 20 is a diagram for explaining a bending amount setting method.
FIG. 21 is a diagram illustrating a state of the bending apparatus 5 in the sixth step of the bending process according to the modification. FIG. 22 is a diagram illustrating a state of the bending apparatus 5 in the seventh process of the bending process. FIG. 23 is a diagram illustrating a state of the bending apparatus 5 in the eighth step of the bending process. FIG. 24 is a diagram illustrating a state of the bending apparatus 5 after the bending process is completed.

When bending the bumper reinforcement B by the bending line 1 is started, first, the material pallet material mounting tables 2 and 3 that accommodate the bumper reinforcement B (linear bumper reinforcement B) are set. . Then, after inputting a product type for the product (bumper reinforcement B after bending) using the input touch panel 11, the start of bending is input. Thereby, the bending process with respect to the bumper reinforcement B by the bending process line 1 is started.
When the bending process on the bumper reinforcement B by the bending line 1 is started, first, the material carry-in device 8 is accommodated in the material pallet mounted on each material mounting table 2, 3. And the bumper reinforcement B is placed at a predetermined processing position of the material inspection / material processing unit 4. Here, the material carry-in device 8 grips the bumper reinforcement B by the gripping device 8a of the arm portion 8b.

When the bumper reinforcement B is installed at a predetermined processing position of the material inspection / material processing unit 4, the material inspection apparatus 4 a sets the cross-sectional dimensions and warpage amounts in advance for the bumper reinforcement B installed at the predetermined processing position. The deformation of the shape with respect to the reference shape is measured, and the measurement result is output to the line control device.
Further, when the processing by the material inspection apparatus 4a is completed, the material processing apparatus 4b performs a purification process on each end of the bumper reinforcement B installed at a predetermined processing position. Specifically, the shape correcting device corrects the deformation (collapse) generated at each end of the bumper reinforcement B, and the cutting device generates a burr generated at each end of the bumper reinforcement B. To cut.

Further, when the processing by the material processing apparatus 4b is finished, as shown in FIG. 10, the material carry-in apparatus 8 grips the bumper reinforcement B installed at the predetermined processing position of the material inspection / material processing unit 4, The bumper reinforcement B is installed on the lower central mold 32 of the bending apparatus 5.
Here, in the bending apparatus 5 before the bending process is started, as shown in FIG. 10, the pressure die 43 (pressing mold 44) is located above the lower mold unit 30 (central lower mold 32). The moving unit 52 of each bending mold unit 50 (each of the right bending mold unit 50 and the left bending mold unit 50) is arranged with respect to the lower mold unit 30 (central lower mold 32). It is arranged at a position separated in the left-right direction.

When the bumper reinforcement B is installed on the lower central mold 32 of the bending apparatus 5, the bending process by the bending apparatus 5 is started.
When the bending process is started, first, the first process is executed. In the first step, as shown in FIG. 11, the pressure die 43 is lowered by the press-type lifting / lowering servo drive device 41. At this time, based on the sectional dimension (vertical dimension) of the bumper reinforcement B input from the material inspection apparatus 4a, the distance between the presser mold 44 and the bumper reinforcement B installed on the central lower mold 32 is predetermined. The pressure die 43 is lowered so as to be a value.

  When the first step is completed, the second step is executed. In the second step, as shown in FIG. 12, in each bending die unit 50, the moving unit 52 is moved toward the lower die unit 30 (central lower die 32) by the pair of base moving servo drive devices 51. , Arranged at a predetermined position. At this time, each moving unit 52 is disposed at a position where the tip of the bumper reinforcement B installed on the central lower mold 32 is disposed on the clamp surface k <b> 3 on the processing surface k of the bending mold 61.

  When the second step is completed, the third step is executed. In the third step, as shown in FIG. 13, in each bending die unit 50, each tubular member of the bumper reinforcement B in which each metal core 67 is installed on the central lower die 32 by the core metal insertion / extraction servo drive device 66. Inserted into the hollow part h of the tubular parts p1 and p2 from the tips of the parts p1 and p2. At this time, in each tubular portion p1, p2, the tip of each core bar 67 extends beyond the R processing target portion b2 to a predetermined position of the R processing non-target portion b1 (in this embodiment, the longitudinal direction of the bumper reinforcement B). Has reached the center of

When the third step is completed, the fourth step is executed. In the fourth step, as shown in FIG. 14, the pressure die 43 is lowered by the press-type lifting / lowering servo drive device 41. At this time, based on the cross-sectional dimension (vertical dimension) of the bumper reinforcement B input from the material inspection apparatus 4a, the presser mold 44 contacts the upper surface of the bumper reinforcement B installed on the central lower mold 32. The pressure die 43 is lowered so as to (suppress). Further, the pressurizing device 42 assists the pressure die 43 to be pushed downward (pressurized) by the presser type lifting / lowering servo drive device 41.
Further, in each bending die unit 50, the clamping member 64 a of the clamping device 64 is lowered, and the tip of the bumper reinforcement B installed on the central lower die 32 is brought into contact with the clamping surface k 3 of the processing surface k of the bending die 61. Fixed.

When the fourth step is completed, the fifth step is executed. In the fifth step, as shown in FIG. 15, in each bending die unit 50, the rotation base 60 (bending die 61) is displaced so that the tip processing portion of the R processing target portion b <b> 2 of the bumper reinforcement B is moved. On the other hand, bending is performed. At this time, the pair of base moving servo driving devices 51, the pair of rotary shaft raising / lowering servo driving devices 58, and the bending die rotating servo driving device 59 cooperate to form the rotating base 60 (bending die 61). Displaced.
The bending process for the front end side processed portion of the bumper reinforcement B is performed by the first arc surface k <b> 1 of the processed surface k of the bending die 61.
Specifically, the rotary base 60 (bending die 61) is displaced so that the first circular arc surface k1 of the bending die 61 rolls on the lower surface of the tip processed portion of the bumper reinforcement B installed on the central lower die 32. Let
That is, as shown in FIGS. 16 and 17, a virtual rotation axis x is set at a predetermined position of the rotation base 60, and the rotation base 60 is rotated about the virtual rotation axis x while the virtual rotation axis x is in the vertical direction. It is moved so as to move toward the inner side (center lower mold 32 side) without changing the position of.

The virtual rotation axis x is set so that the neutral axis (neutral surface) is outside the center in the vertical direction (thickness direction) of the tip side processed portion of the bumper reinforcement B. In particular, the neutral axis is set within the range of 60 to 70 [%] from the lower surface (R inner surface) of the tip side processed portion (the range in which the compressive stress acts in the thickness direction is 60 to 70 [%]. The virtual rotation axis x is set so that it falls within the range of Here, the “neutral axis (neutral plane)” refers to a place (plane) where stress (tensile stress and compressive stress) does not act when bending is performed.
In the present embodiment, the virtual rotation axis x is set to coincide with the center of curvature of the first circular arc surface k1. The rotation radius of the rotation base 60 by the virtual rotation axis x is smaller than the rotation radius of the rotation base by the rotation axis T (virtual rotation axis y described later).
As shown in FIG. 16, at the start of the bending process on the tip side processed portion by the first arc surface k1, the start end portion of the first arc surface k1 is arranged at the highest position, and the start end portion of the first arc surface k1 is It is in contact with the lower surface of the tip side processed part. Further, the virtual rotation axis x is located directly below the starting end of the first arcuate surface k1.
Then, the rotation base 60 (bending mold 61) is displaced so that the virtual rotation axis x is moved around the virtual rotation axis x while being moved in parallel in the left-right direction. At this time, the rotation base 60 is displaced by adjusting the ratio of the position speed of the servo motor 51a of the pair of base moving servo drive devices 51 and the servo motor 59a of the bending-type rotation servo drive device 59.

Here, when the first tubular portion p1 and the second tubular portion p2 have different cross-sectional shapes orthogonal to the longitudinal direction, the virtual rotation axis x is moved in a state inclined at a predetermined angle with respect to the horizontal direction. Let Thereby, the bending R can be made different between the first tubular portion p1 and the second tubular portion p2. In this case, the positions of the servo motor 51a of the pair of base-moving servo driving devices 51, the servo motor 59a of the bending-type rotating servo driving device 59, and the servo motor 59a of the servo driving device 58 for lifting and lowering both rotary shafts. By adjusting the speed ratio, the rotary base 60 is displaced.
Then, at the end of the bending process on the distal end side processed portion by the first arc surface k1, as shown in FIG. 17, the end portion of the first arc surface k1 is arranged at the highest position, and the entire area of the first arc surface k1 is It is in contact with the lower surface of the tip side processed part.
Further, in the fifth step, in each bending die unit 50, the hollow core h of each tubular portion p1, p2 is formed by the servo drive device 66 for inserting / removing the metal core in synchronization with the displacement of the rotation base 60 (bending die 61). Each 67 core metal inserted is pulled out at a predetermined speed. Here, at the time of bending by the first arc surface k1, each core metal 67 is pulled out at a slower speed than at the time of bending by the second arc surface k2.

When the fifth step is completed, the sixth step is executed. In the sixth step, as shown in FIG. 18, in each bending die unit 50, the rotation base 60 (bending die 61) is displaced so that the center processing portion of the R processing target portion b <b> 2 of the bumper reinforcement B is moved. On the other hand, bending is performed. At this time, the pair of base moving servo driving devices 51, the pair of rotary shaft raising / lowering servo driving devices 58, and the bending die rotating servo driving device 59 cooperate to form the rotating base 60 (bending die 61). Displaced.
The bending of the center side processed portion of the bumper reinforcement B is performed by the second arc surface k2 of the processed surface k of the bending die 61.
Specifically, the rotary base 60 (bending die 61) is displaced so that the second arc surface k2 of the bending die 61 rolls on the lower surface of the tip processed portion of the bumper reinforcement B installed on the central lower die 32. Let
That is, as shown in FIGS. 17 and 19, a virtual rotation axis y is set at a predetermined position of the rotation base 60, and the rotation base 60 is rotated around the virtual rotation axis y while the virtual rotation axis y is in the vertical direction. It is moved so as to move toward the inner side (center lower mold 32 side) without changing the position of.

The virtual rotation axis y is set so that the neutral axis (neutral surface) is inside the center in the vertical direction (thickness direction) of the central processing portion of the bumper reinforcement B. In particular, the neutral axis is set within the range of 30 to 40 [%] from the lower surface (R inner surface) of the center side processed portion (the range in which the compressive stress acts in the thickness direction is 30 to 40 [%]. The virtual rotation axis y is set so that it falls within the range of
In the present embodiment, the virtual rotation axis y is set to coincide with the center of curvature of the second arcuate surface k2. In particular, the virtual rotation axis y coincides with the center of the rotation axis T. Thereby, the rotation radius of the rotation base 60 by the virtual rotation axis y is larger than the rotation radius of the rotation base by the virtual rotation axis x.
As shown in FIG. 17, at the start of the bending process on the tip side processed portion by the second arc surface k2, the start end portion of the second arc surface k2 is arranged at the highest position, and the start end portion of the second arc surface k2 is It is in contact with the lower surface of the central processing part. Further, the virtual rotation axis y is located directly below the starting end portion of the second arcuate surface k2.
Then, the rotation base 60 (bending die 61) is displaced so that the virtual rotation axis y is rotated around the virtual rotation axis y while being moved in parallel in the left-right direction. At this time, the rotation base 60 is displaced by adjusting the ratio of the position speed of the servo motor 51a of the pair of base moving servo drive devices 51 and the servo motor 59a of the bending-type rotation servo drive device 59.

Here, when the first tubular portion p1 and the second tubular portion p2 have different cross-sectional shapes orthogonal to the longitudinal direction, the virtual rotation axis y is moved in a state inclined at a predetermined angle with respect to the horizontal direction. Let Thereby, the bending R can be made different between the first tubular portion p1 and the second tubular portion p2. In this case, the positions of the servo motor 51a of the pair of base-moving servo driving devices 51, the servo motor 59a of the bending-type rotating servo driving device 59, and the servo motor 59a of the servo driving device 58 for lifting and lowering both rotary shafts. By adjusting the speed ratio, the rotary base 60 is displaced.
Then, at the end of the bending process on the center-side processed portion by the second arc surface k2, as shown in FIG. 19, the end portion of the second arc surface k2 is arranged at the highest position, and the entire area of the second arc surface k2 is It is in contact with the lower surface of the central processing part.
Further, in the sixth step, in each bending die unit 50, in the hollow portion h of each tubular portion p1, p2 by the servo drive device 66 for inserting / removing the metal core in synchronization with the displacement of the rotation base 60 (bending die 61). Each 67 core metal inserted is pulled out at a predetermined speed. Here, at the time of bending with the second arcuate surface k2, each core metal 67 is pulled out at a higher speed than at the time of bending with the first arcuate surface k1.

In particular, in each bending die unit 50, the bending amount of the center side processed portion by the second arcuate surface k2 is changed based on the warping amount of the bumper reinforcement B input from the material inspection apparatus 4a. Here, the “bending amount” refers to the degree to which the bumper reinforcement B (center side processed portion) is bent with respect to the bending of the processing surface k (second arc surface k2). The curvature of the bumper reinforcement B (R machining target part b2) is close to the curvature of the machining surface k.
As shown in FIG. 20, the adjustment of the bending amount is performed by adjusting the rotation angle A [°] of the rotation base 60 (bending mold 61) around the virtual rotation axis y and the movement amount B [mm] of the virtual rotation axis y. This is done by adjusting the ratio. Specifically, the bending amount increases as the movement amount B [mm] with respect to the rotation angle A [°] increases.
Further, in each bending die unit 50, it is possible to change the bending moment with respect to the bumper reinforcement B (center side processed portion) by changing the position (clamp position) where the bumper reinforcement B is fixed by the clamp device 64. It has become. And the bending R of the bumper reinforcement B (R processing object part b2) after a springback becomes small, so that the bending moment with respect to the bumper reinforcement B (center side processing part) becomes large.
Specifically, as shown in FIG. 21, when it is desired to increase the bending moment, the distance L between the highest position and the clamping position of the processing surface k (second arc surface k2) of the bending die 61 is set long. In order to reduce the bending moment, the distance L is set short.

When the sixth step is completed, the seventh step is executed. In the seventh step, as shown in FIG. 22, in each bending die unit 50, each tubular member of the bumper reinforcement B in which each metal core 67 is installed on the central lower mold 32 by the core metal insertion / extraction servo drive device 66. It is extracted from the hollow part h of the parts p1 and p2.
Further, in each bending die unit 50, the clamp member 64a of the clamping device 64 is raised, and the fixation of the bumper reinforcement B to the machining surface k of the bending die 61 is released. At this time, the tip of the bumper reinforcement B jumps up along a predetermined locus close to the involute curve by the spring back.
Therefore, the clamp device 64 (clamp member 64a) moves along the predetermined locus by synchronizing the rise of the clamp member 64a by the clamp device 64 and the rotation of the columnar base 63 by the clamp position moving servo drive device 62. While being done, the clamp member 64a of the clamp device 64 is raised. As a result, deformation of the tip of the bumper reinforcement B due to the spring back is prevented.

When the seventh step is completed, the eighth step is executed. In the eighth step, as shown in FIG. 23, the pressure die 43 is raised by the presser type lifting / lowering servo drive device 41. At this time, the product pressing portion of the product pressing device 45 is lowered so that the position of the bumper reinforcement B on the central lower mold 32 is not shifted, and the pressure is pressed while the product pressing portion presses the upper surface of the bumper reinforcement B. The die 43 is raised.
When the seventh step is completed, the bending process by the bending apparatus 5 ends.

When the bending process by the bending apparatus 5 is completed, as shown in FIG. 24, the product carry-out apparatus 9 holds the bumper reinforcement B placed on the central lower mold 32, and the bumper reinforcement B Is installed at a predetermined inspection position of the product inspection apparatus 6. Here, the material carry-out device 9 holds the bumper reinforcement B by the holding device 9a of the arm portion 9b.
When the bumper reinforcement B is installed at the predetermined inspection position of the product inspection device 6, the product inspection device 6 measures the bending R, the state of occurrence of the dent, etc. with respect to the bumper reinforcement B installed at the predetermined inspection position, The measurement result is output to a line control device described later.
When the processing by the product inspection device 6 is completed, the material carry-out device 9 grips the bumper reinforcement B installed at a predetermined inspection position of the product inspection device 6 and places the bumper reinforcement B on the product mounting table 7. Store in the product pallet on which it is placed.
Thus, the bending process for the bumper reinforcement B by the bending process line 1 is completed. And in the bending process line 1, a bending process is given with respect to several bumper reinforcement B by repeating the said process.

(Operation and effect of the bending apparatus 5)
In the bending apparatus 5, no tensile force is applied to the bumper reinforcement B by the clamp mechanism 55. Accordingly, it is not necessary to grip each end portion of the bumper reinforcement B with a strong force by the clamping device 64, and deformation of each end portion of the bumper reinforcement B can be suppressed.
Therefore, each end of the bumper reinforcement B is not cut and discarded, and the amount of waste can be reduced.
In the bending apparatus 5, the first arc surface k <b> 1 formed on the start end side and the second arc surface k <b> 2 formed on the end side are formed on the processing surface k of the bending die 61. Further, the curvature radius R1 of the first arc surface k1 is set smaller than the curvature radius R2 of the second arc surface k2.
Thereby, about the front end side processing part of the R processing target part b2 in the bumper reinforcement B, the bending process is performed by the first circular arc surface k1 having a small curvature radius, and about the center side processing part of the R processing target part b2. Is bent by the second arc surface k2 having a large curvature radius.
In particular, the bending device 5 includes servo mechanisms (a pair of base-moving servo driving devices 51, a pair of rotary shaft raising / lowering servo driving devices 58, a bending-type rotating servo driving device 59, and a bending processing control unit 10). Different virtual rotation axes x and y are set for the bending process using the first circular arc surface k1 and the bending process using the second circular arc surface k2, and the bending die 61 is rotated about the set virtual rotation axes x and y. .
As a result, the bending die 61 is rotated around the virtual rotation axis x related to the small turning radius when bending the tip side processed portion, while the virtual rotating shaft related to the large turning radius is bent when bending the center side processed portion. The bending die 61 can be rotated around y.
Specifically, at the time of bending by the first arc surface k1, a virtual rotation axis x is set at the center of curvature of the first arc surface k1, and bending is performed on the distal end side processed portion, while the second arc At the time of bending by the surface k2, it is possible to set the virtual rotation axis y at the center of curvature of the second arcuate surface k2 and perform bending on the center side processed portion.
Therefore, for the tip side processed part where the spring back is strong and the dent is difficult to occur, by applying a bending process with a small bending radius, the spring back can be suppressed without generating a dent. The accuracy with respect to the bending R to be performed can be improved. On the other hand, for the center side processed part where spring back is weak and dents are likely to occur, bending is suppressed with a large bending radius, thereby suppressing the occurrence of dents without reducing the accuracy of the target bending R. can do.

Further, in the bending device 5, when the first arcuate surface k1 is bent with respect to the front end side processed portion, the neutral axis (neutral surface) is set outside the center in the thickness direction of the front end side processed portion, so that the front end In the thickness direction of the side processed portion, the range in which compressive stress acts is wider than the range in which tensile stress acts. Thereby, the spring back can be suppressed and the accuracy with respect to the target bending R can be improved.
On the other hand, when the second arcuate surface k2 is bent with respect to the center-side processed portion, the neutral axis (neutral surface) is set inward from the center in the thickness direction of the tip-side processed portion, so that the thickness direction of the center-side processed portion is , The range in which the compressive stress acts is narrower than the range in which the tensile stress acts. Thereby, generation | occurrence | production of a dent can be suppressed.

Further, in the bending apparatus 5, it is possible to prevent the twisted portion from being twisted by inclining the virtual rotation axes x and y according to the cross-sectional shape of the bumper reinforcement B. It becomes possible.
Further, in the bending apparatus 5, by a servo mechanism (a pair of base-moving servo drive apparatuses 51, a pair of rotary shaft raising / lowering servo drive apparatuses 58, a bending mold rotation servo drive apparatus 59, and a bending process control unit 10). In synchronization with the displacement of the bending die 61, the cored bar 67 inserted into the hollow portion h is pulled out.
Accordingly, it is possible to bend the bumper reinforcement B with the bending die 61 while applying a tensile force to the bumper reinforcement B with the cored bar 67, and to suppress the occurrence of the dent. Become.
In particular, in the bending apparatus 5, the core metal is pulled out at a higher speed when bending by the second arc surface k2 than when bending by the first arc surface k1. As a result, when bending the center side processed part, compared to when bending the tip side processed part, bending is performed while applying a strong tensile force, and the generation of dents can be suppressed more reliably. It becomes.
Further, in the bending apparatus 5, the bending moment applied to the bumper reinforcement B can be changed by changing the clamp position of the bumper reinforcement B by the clamp device 64.

B Bumper reinforcement b1 R processing non-target part b2 R processing target part 1 Bending line 2, 3 Material placing table 4 Material inspection / material processing unit 4a Material inspection device 4b Material processing device 5 Bending device 6 Product inspection device 7 Product Mounting table 8 Material carry-in device 9 Product carry-out device 10 Bending control unit 11 Input touch panel 12 Centralized control sequencer A Servo amplifier 20 Housing 30 Lower die unit 32 Center lower die 40 Presser type unit 41 Presser type lifting / lowering servo drive device 44 Presser Mold 50 Bending die unit 51 Servo drive device for base movement 52 Moving unit 53 Base mechanism portion 54 Mold mechanism portion 55 Clamp mechanism portion 56 Core metal mechanism portion 57 Moving base 58 Servo drive device for rotating shaft raising / lowering T Rotating shaft 59 Bending die Servo drive device for rotation 60 Rolling base 61 bending tool k processing surface k1 first arcuate surface k2 second arcuate surface 62 clamping position moving servo drive 63 columnar base 64 clamping device 66 the metal core insertion servo drive device 67 the core metal 67a metal core pieces

Claims (10)

A bending die having a machining surface corresponding to a target bending shape;
A pressing mold that holds the bumper reinforcement in cooperation with the bending mold;
A clamp mechanism for fixing the bumper reinforcement to the bending mold;
A servo mechanism for controlling the displacement of the bending mold,
The machining surface has a first arc surface formed on the start side and a second arc surface formed on the end side,
The radius of curvature of the first arc surface is set smaller than the radius of curvature of the second arc surface,
The servo mechanism sets a virtual rotation axis that is different between the bending process using the first arc surface and the bending process using the second arc surface, and rotates the bending mold around the set virtual rotation axis. Bumper reinforcement bending machine, characterized in that   When bending by the first arc surface, the neutral axis is set outside the center of the bumper reinforcement in the thickness direction, and when bending by the second arc surface, the neutral axis is the center of the bumper reinforcement in the thickness direction. The bumper reinforcement bending apparatus according to claim 1, wherein the bending apparatus is set on an inner side.   The bumper reinforcement bending apparatus according to claim 1, wherein the servo mechanism is capable of inclining the virtual rotation axis according to a cross-sectional shape of the bumper reinforcement. A cored bar inserted into the hollow portion of the bumper reinforcement;
A second servo mechanism for controlling withdrawal of the core metal inserted into the hollow portion,
The metal core is formed by connecting a plurality of metal core pieces,
The second servo mechanism pulls out the core metal inserted into the hollow portion in synchronization with the displacement of the bending die by the servo mechanism, and the first arc is at the time of bending by the second arc surface. The bumper reinforcement bending apparatus according to any one of claims 1 to 3, wherein the cored bar is pulled out at a higher speed as compared with a bending process by a surface.   The bumper reinforcement bending apparatus according to any one of claims 1 to 4, further comprising clamp position changing means capable of changing a clamp position of the bumper reinforcement by the clamp mechanism. . The bumper reinforcement is bent by clamping the bumper reinforcement by fixing the bumper reinforcement to a bending die having a machining surface corresponding to a target bending shape by a clamp mechanism, and displacing the bending die. A method,
A first step of bending the bumper reinforcement by a first arc surface formed on the start end side of the processing surface;
A second step of bending the bumper reinforcement by a second arcuate surface formed on the terminal side of the processed surface,
The radius of curvature of the first arc surface is set smaller than the radius of curvature of the second arc surface,
2. A bumper reinforcement bending method, wherein different virtual rotation axes are set in the first step and the second step, and the bending die is rotated around the set virtual rotation axis. In the first step, the neutral axis is set outside the center in the thickness direction of the bumper reinforcement,
7. The bumper reinforcement bending method according to claim 6, wherein, in the second step, a neutral axis is set inside a center in a thickness direction of the bumper reinforcement.   The bumper according to claim 6 or 7, wherein, in at least one of the first step and the second step, the virtual rotation axis is inclined according to a cross-sectional shape of the bumper reinforcement. Reinforcement bending method. In each of the first step and the second step, the cored bar inserted in the hollow portion of the bumper reinforcement is pulled out in synchronization with the displacement of the bending die,
The metal core is formed by connecting a plurality of metal core pieces,
9. The bumper reinforcement bending process according to claim 6, wherein in the second step, the metal core is pulled out at a higher speed than in the first step. 10. Method. The bending of the bumper reinforcement according to any one of claims 6 to 9, wherein a clamping position of the bumper reinforcement by the clamp mechanism is changed in the first step and the second step. Processing method.

Images