WO2018173997A1 - Die mold for assymetrical bending, mold set for assymetrical bending, and bending processing method - Google Patents

Abstract

A first bending block 38 working with a first punch tip surface 18f for a punch mold 18 for bending one side of a part S corresponding to a bending line in a workpiece W to a first curvature angle θ1 is provided so as to be movable vertically via a plurality of guide bolts 40 in an accommodation recess 36 of a die mold base 28. A second bending block 44 working with a second punch tip surface 18s of a punch mold 18 for bending the other side of the part S corresponding to the bending line in the workpiece W to a second curvature angle θ2 is provided on the back surface side of the first bending block 38 in the accommodation recess 36 of the die mold base 28. A recessed processing step 58 for progress of the tip part of the punch mold 18 is formed on the edge of the back surface side of the upper surface of the first bending block 38.

Description

Die mold for asymmetric bending, mold set for asymmetric bending, and bending method

The present invention relates to a die for asymmetric bending used when performing asymmetric bending on a workpiece.

Generally, bending performed by a press brake is called symmetrical bending (uniform bending). Symmetric bending means that both sides (front part and rear part) of the part corresponding to the bending line in the workpiece are symmetrical with respect to the vertical direction (vertical direction) when viewed from the side (one side in the mold length direction). Bending to be. In other words, the symmetric bending means that both sides of the part corresponding to the bending line in the workpiece are bent at the same bending angle.

In recent years, asymmetric bending (unbalanced bending) may be performed in place of symmetrical bending in order to reduce the jumping of the workpiece on the front side (front side) of the press brake or to manufacture a deep bending product. Asymmetric bending refers to bending so that both sides of a portion corresponding to a bending line in a workpiece are asymmetric with respect to the vertical direction when viewed from the side (one side in the mold length direction). Specifically, one side (front side portion) of the portion corresponding to the bending line in the workpiece is set to a first bending angle smaller than 45 °, and the other side (rear side portion) of the portion corresponding to the bending line in the workpiece is set to 45. Bending to a second bending angle greater than °.

When performing asymmetric bending on the workpiece, a punch mold for asymmetric bending that can be attached to and detached from the lower end of the upper table in the press brake, and an asymmetric that can be attached to and detached from the upper end of the lower table in the press brake An asymmetric bending mold set including a bending die mold is used. Further, a first punch inclined at the same angle as the first bending angle with respect to the horizontal direction (horizontal line) passing through the tip edge of the punch die is formed on the front side (front side portion) of the tip portion of the asymmetric punch die. A tip surface is formed. A second punch tip surface that is inclined by the same angle as the second bending angle with respect to the horizontal direction passing through the tip edge of the punch die is formed on the back side (rear part) of the tip portion of the asymmetric punch die. Has been. Further, the machining groove (V groove) of the die mold for asymmetric bending is formed in a shape corresponding to the tip of the punch mold for asymmetric bending.

In addition, there exists a thing shown in patent document 1 as a prior art relevant to this invention.

JP 2011-36864 A

By the way, the horizontal component of the bending load that works at the corner (first shoulder round portion) on the back side (rear side) of the machining groove of the die mold is the corner on the front side (front side) of the machining groove of the die mold ( Compared to the horizontal component of the bending load that works in the second shoulder radius part), it becomes larger according to the difference between the second bending angle and the first bending angle. In other words, when performing asymmetric bending on the workpiece, a thrust load (a load in the front-rear direction) according to the difference between the second bending angle and the first bending angle acts on the mold set and the press brake.

On the other hand, if an excessive thrust load is applied to the mold set or press brake, the mold set or press brake will be damaged. Therefore, when asymmetric bending is performed on the workpiece, the workpiece thickness (plate thickness), material, and bending length (corresponding to the bending line) are used so that excessive thrust load does not act on the mold set and press brake. The processing range (processing conditions) such as the length of the part was limited.

A method of reducing the thrust load acting on the mold set and the press brake by arranging a punch receiving member made of urethane in the machining groove of the die mold is also conceivable. In this case, the bending accuracy is lowered by the punch receiving member.

That is, when asymmetric bending is performed on a workpiece by a press brake, there is a problem that it is difficult to expand a processing range such as the thickness, material, and bending length of the workpiece while maintaining bending accuracy.

The present invention has been made paying attention to the above-described circumstances, and an object thereof is to provide a die mold for asymmetric bending and the like having a novel configuration.

According to a first aspect of the present invention, in a die mold for asymmetric bending (lower mold) used when performing asymmetric bending with respect to a workpiece by a press brake, a die mold having an accommodation recess on the upper side (upper side). One of the portions corresponding to the bending line in the work in cooperation with the punch die (upper die) for asymmetric bending, which is provided so as to be movable in the vertical direction in the receiving recess of the die die base. A first bending block for bending the side (front side portion) to a first bending angle smaller than 45 °, a biasing member for biasing the first bending block upward, and the accommodation of the die mold base Provided on the back side of the first bending block in the recess, and cooperates with the punch die to make the other side (rear part) of the part corresponding to the bending line in the workpiece to a second bending angle larger than 45 °. To bend A second bending block, a rear edge of the upper surface of the first bending block, a front edge of the upper surface of the second bending block, or an upper surface of the first bending block and the second A recessed processing step (processing recess) for allowing the tip of the punch die to enter is formed in a portion extending over the upper surface of the bending block.

According to the first aspect of the present invention, the workpiece is positioned with respect to the die mold so that the portion corresponding to the bending line in the workpiece is located above the machining step. Thereafter, the punch die is moved downward, and the tip end portion of the punch die enters the processing step portion. Thereby, one side (front part) of the part corresponding to the bending line in the workpiece is sandwiched between the punch tip surface of the punch die and the back side (rear side) corner of the upper surface of the first bending block. The first bending angle can be bent. At the same time, the other side (rear part) of the part corresponding to the bending line in the workpiece can be bent to the first bending angle by the front side (front side) corner of the upper surface of the second bending block.

The punch die is further moved downward, the first bending block is moved downward against the urging force of the urging member, and the second bending block is moved to the upper surface of the first bending block. Project upward. Accordingly, the bending line in the workpiece is increased by the front corner portion of the upper surface of the second bending block while the distance between the front edge of the punch die and the upper corner portion of the second bending block is increased. The other side (rear side portion) of the portion corresponding to can be bent from the first bending angle to the second bending angle.

Here, the horizontal component of the bending load acting on the front side (front side) corner of the upper surface of the second bending block is the bending load acting on the rear side (rear side) corner of the upper surface of the first bending block. Compared to the horizontal component, it tends to increase according to the difference between the second bending angle and the first bending angle. On the other hand, when the other side (rear part) of the part corresponding to the bend line in the workpiece is bent from the first bending angle to the second bending angle, the front end edge of the punch die and the upper surface of the second bending block are faced. Since the distance to the corner portion on the side is enlarged, the horizontal component of the bending load acting on the corner portion on the front side on the upper surface of the second bending block can be reduced. Therefore, when the workpiece is asymmetrically bent without providing a punch receiving member made of urethane in the die die, the die set consisting of the punch die and the die die, and the press brake The working thrust load (the load in the front-rear direction) can be reduced.

The second aspect of the present invention is a mold set for asymmetric bending used when performing asymmetric bending with respect to a workpiece by a press brake, and is attachable to and detachable from a lower end portion of an upper table in the press brake. Punch die for asymmetric bending (upper die) having a punch tip surface inclined at the same angle as the first bending angle smaller than 45 ° with respect to the horizontal direction (horizontal line) passing through the tip edge on the front side of the tip portion Mold) and a die mold (lower mold) for asymmetric bending that is detachable from the upper end of the lower table in the press brake and has the configuration of the first aspect of the present invention. It is.

According to the second aspect of the present invention, the same action as that of the first aspect of the present invention is achieved.

According to a third aspect of the present invention, in the bending method for performing asymmetric bending with respect to the workpiece by a press brake, the front side (front side) of the tip is smaller than 45 ° with respect to the horizontal direction passing through the tip edge. Using a die mold base for asymmetrical bending (upper mold) in which a punch tip surface inclined by the same angle as the first bending angle is formed, and having an accommodating recess in the upper part (upper side); A first bending block provided in the housing recess of the die mold base so as to be movable in the vertical direction; and a back surface side (rear side) of the first bending block in the housing recess of the die mold base. A second bending block, and a rear side (rear side) edge of the upper surface of the first bending block, a front side (front side) edge of the upper surface of the second bending block, or the first bending block. Top surface and said 2 Using a die mold (lower mold) for asymmetric bending in which a recessed processing step (processing recess) is formed in a portion extending over the upper surface of the bending block, the portion corresponding to the bending line in the workpiece is the processing step In a state where the punch die is positioned on the upper side of the punch die, the punch die is moved downward, and the tip end portion of the punch die is entered into the processing step portion. The second bending block is simultaneously bent to the first bending angle by sandwiching one side (front side portion) of the portion corresponding to the bending line in the workpiece by the back side (rear side) corner of the upper surface of the first bending block. A first bending step of bending the other side (rear side portion) of the portion corresponding to the bending line in the workpiece to a first bending angle by the front side (front side) corner portion of the upper surface of the upper surface of the upper surface, and further lowering the punch die Move the first By moving the bending block downward and projecting the second bending block upward with respect to the upper surface of the first bending block, the tip edge of the punch die and the upper surface of the second bending block are placed. While increasing the distance from the front (front) corner, the first bend of the other side (rear portion) of the part corresponding to the bending line in the workpiece is performed by the front corner of the upper surface of the second bending block. And a second bending step of bending from an angle to a second bending angle greater than 45 °.

According to the third aspect of the present invention, the horizontal component of the bending load acting on the front side (front side) corner of the upper surface of the second bending block is the back side (rear side) of the upper surface of the first bending block. Compared to the horizontal component of the bending load that works at the corner, it tends to increase according to the difference between the second bending angle and the first bending angle. On the other hand, when the other side (rear part) of the part corresponding to the bending line in the workpiece is bent from the first bending angle to the second bending angle, the punch tip and the upper surface of the second bending block face the front side (front side). ) Is enlarged, the horizontal component of the bending load acting on the front side (front side) corner on the upper surface of the second bending block can be reduced. Therefore, a thrust load (front-rear direction) acting on the punch die, the die die, and the press brake when the workpiece is asymmetrically bent without providing the die die with a punch receiving member made of urethane. ) Can be reduced.

FIG. 1 is a side view showing a mold set for asymmetric bending according to the first embodiment. FIG. 2 is an enlarged side cross-sectional view showing a mold set for asymmetric bending according to the first embodiment. FIG. 3A is a front view of the die mold for asymmetric bending according to the first embodiment, and FIG. 3B is a rear view of the die mold for asymmetric bending according to the first embodiment. is there. FIGS. 4A and 4B are cross-sectional views for explaining the operation of the asymmetric bending mold set according to the first embodiment. Fig.5 (a) is sectional drawing explaining operation | movement of the metal mold | die set for asymmetric bending based on 1st Embodiment, FIG.5 (b) is an expanded sectional view of the I section in Fig.5 (a). It is. FIG. 6 is a side view showing how a deep bent product is manufactured using the asymmetric bending die set according to the first embodiment. FIG. 7 is a side view showing a mold set for asymmetric bending according to the second embodiment. FIG. 8 is an enlarged side sectional view showing a mold set for asymmetric bending according to the second embodiment. FIG. 9A is a front view of an asymmetric bending die die according to the second embodiment, and FIG. 9B is a rear view of the asymmetric bending die die according to the second embodiment. is there. FIGS. 10A and 10B are cross-sectional views illustrating the operation of the asymmetric bending mold set according to the second embodiment. Fig.11 (a) is sectional drawing explaining operation | movement of the metal mold | die set for asymmetric bending based on 2nd Embodiment, FIG.11 (b) is an expanded sectional view of the II section in Fig.11 (a). It is. FIG. 12 is a side view showing how a deep bent product is manufactured using the asymmetric bending die set according to the second embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment and Second Embodiment will be described with reference to the drawings.

In the specification and claims of the present application, “provided” means not only being provided directly but also indirectly provided via another member. “Mounted” means not only directly mounted but also indirectly mounted via a separate member. The “die width direction” refers to the width direction of the asymmetric bending punch die or the asymmetric bending die die, and in the embodiment of the present invention, it refers to the front-rear direction. . “Die length direction” refers to the length direction of a punch mold for asymmetric bending or a die mold for asymmetric bending. In the embodiment of the present invention, it refers to the left-right direction. . In the drawing, “DA” is the mold width direction, “FF” is the front direction (one side in the mold width direction), “FR” is the rear direction (the other side in the mold width direction), “DB”. Is the mold length direction, “L” is the left direction (one side of the mold length direction), “R” is the right direction (the other side of the mold length direction), and “U” is the top direction. The direction “D” indicates the downward direction.

(First embodiment)
As shown in FIGS. 1 and 2, the asymmetric bending die set 10 according to the first embodiment performs asymmetric bending on a plate-shaped workpiece (sheet metal) W by a press brake (only part of which is shown). It is a mold set used in the case. Further, the asymmetric bending die set 10 is a punch metal for asymmetric bending which is detachably attached to a lower end portion of an upper table 12 (only a part is shown) in a press brake via an intermediate plate 14 and a mounting bolt 16. It consists of a die 18 and a die die 24 for asymmetric bending that is detachably attached to an upper end portion of a lower table 20 (only a part is shown) in a press brake via a lower die holder 22.

First, the configuration of an asymmetric bending punch die (upper die) 18 according to the first embodiment will be briefly described.

As shown in FIGS. 1 and 2, the asymmetric bending punch die 18 extends in the die length direction DB (left-right direction). A shank portion 26 for mounting the punch die 18 to the lower end portion of the upper table 12 is formed along the die length direction DB at the base end portion (upper end portion) of the punch die 18. . A first punch tip surface 18f is formed along the die length direction DB on the front side (front portion) of the tip portion of the punch die 18. The first punch tip surface 18f of the punch die 18 has a first bending angle θ1 (see FIG. 5B) smaller than 45 ° with respect to the horizontal direction (horizontal line) passing through the tip edge 18t of the punch die 18. It is inclined by the same angle. Furthermore, a second punch tip surface 18s is formed along the die length direction DB (left and right direction) on the back side (rear side portion) of the tip portion of the punch die 18. The second punch tip surface 18s of the punch die 18 is the same angle as the second bending angle θ2 (see FIG. 5B) larger than 45 degrees with respect to the horizontal direction passing through the tip edge 18t of the punch die 18. Inclined.

Here, the first bending angle θ1 is a bending angle on one side (front side portion) of the portion S ′ corresponding to the bending line in the workpiece W. In the embodiment of the present invention, the first bending angle θ1 is 15 as an example. It is set to ~ 35 degrees. The second bending angle θ2 is a bending angle on the other side (rear side portion) of the portion S ′ corresponding to the bending line in the workpiece W, and is set to 65 to 75 degrees as an example. The portion corresponding to the bending line in the workpiece W refers to a portion that becomes a bending line S (see FIG. 5B) by bending. Note that the second punch tip surface 18s of the punch die 18 only needs to be inclined at a second bending angle θ2 or more with respect to the horizontal direction passing through the tip edge 18t of the punch die 18, and the tip edge of the punch die 18 You may incline 90 degree | times with respect to the horizontal direction which passes 18t.

Subsequently, the configuration of the die mold (lower mold) 24 for asymmetric bending according to the first embodiment will be specifically described.

As shown in FIGS. 1 to 3A and 3B, the die mold 24 for asymmetric bending is a die mold base that can be attached to and detached from the upper end of the lower table 20 via a plurality of lower mold holders 22. (Lower mold base) 28 is provided, and the die mold base 28 extends in the mold length direction DB (left-right direction). Further, an upper side (upper surface) of the die mold base 28 is an L-shaped die mold base main body 30 and a back fixed to the back surface of the die mold base main body 30 via a plurality of mounting bolts 32. A plate 34 is provided. The die mold base 28 has an accommodation recess 36 extending in the mold length direction DB on the upper side (upper side), and both sides of the accommodation recess 36 in the mold length direction DB are opened. .

In the housing recess 36 of the die mold base 28, one side (front part) of the portion S corresponding to the bending line in the workpiece W in cooperation with the first punch tip surface 18 f of the punch mold 18 is a first bending angle. A first bending block 38 for bending to θ1 is provided. The first bending block 38 extends in the mold length direction DB (left-right direction), and a first slidable contact surface 38f inclined with respect to the vertical direction is formed at the lower part of the first bending block 38 in the mold length. It is formed along the direction DB.

The first bending block 38 is configured to be movable in the vertical direction via a plurality of guide bolts 40. In other words, the first bending block 38 is provided in the housing recess 36 of the die mold base 28 so as to be movable in the vertical direction via the plurality of guide bolts 40. As shown in FIG. 2, each guide bolt 40 is supported by a long hole 30h formed in the upper part of the die mold base body 30 so as to be movable in the vertical direction. A coil spring 42 is provided below the guide bolts 40 in the die mold base body 30 as a first bending block urging member that urges the first bending block 38 upward.

On the back side (rear side) of the first bending block 38 in the housing recess 36 of the die mold base 28, a portion corresponding to a bending line in the workpiece W in cooperation with the second punch tip surface 18 s of the punch mold 18. A second bending block 44 is provided for bending the other side (rear part) of S to the second bending angle θ2. The second bending block 44 extends in the mold length direction DB (left-right direction), and a second slidable contact surface 44s inclined with respect to the vertical direction is formed at the lower part of the second bending block 44 in the mold length. It is formed along the direction DB. The second sliding contact surface 44 s of the second bending block 44 is adjacent to the first sliding contact surface 38 f of the first bending block 38.

The second bending block 44 is configured to be movable in the vertical direction via a plurality of guide bolts 46. In other words, the second bending block 44 is provided on the back side of the first bending block 38 in the housing recess 36 of the die mold base 28 so as to be movable in the vertical direction via the plurality of guide bolts 46. As shown in FIG. 2, each guide bolt 46 is supported by a long hole 38h formed in the upper part of the back plate 34 so as to be movable in the vertical direction. Each elongated hole 38h of the back plate 34 is provided with a coil spring 48 as a biasing member for a second bending block that biases the second bending block 44 downward.

A cam block 50 extending in the mold length direction DB (left-right direction) is provided on the bottom side of the housing recess 36 of the die mold base 28. Further, on one side FF (front side portion) in the mold width direction DA at the upper part of the cam block 50, the first cam surface 50f slidably contacting the first slidable contact surface 38f of the first bending block 38 is formed in the mold width direction DA. The first cam surface 50f is inclined with respect to the vertical direction. Furthermore, on the other side FR (rear part) of the mold length direction DB in the upper part of the cam block 50, the second cam surface 50s slidably contacting the second slidable contact surface 44s of the second bending block 44 has a mold length. The second cam surface 50s is inclined with respect to the vertical direction.

The cam block 50 is configured to be movable (displaceable) in the mold width direction DA (front-rear direction) via a plurality of guide bolts 52 (only one is shown). In other words, the cam block 50 is provided on the bottom side of the housing recess 36 of the die mold base 28 so as to be movable in the mold width direction via the plurality of guide bolts 52. Each guide bolt 52 is supported by a long hole 30b formed in the lower part (bottom part) of the die mold base body 30 so as to be movable in the mold width direction DA.

A plurality of support bolts 54 are provided on the front surface (front side surface) of the cam block 50 at intervals in the mold length direction DB. As shown in FIG. 2, each support bolt 54 is supported by a guide hole 30p formed in an intermediate portion of the die mold base body 30 so as to be movable in the mold width direction DA (front-rear direction). Further, between the head of each guide bolt 40 and the front surface of the die mold base body 30, there is a cam block attachment that urges the cam block 50 to one side FF (forward direction) in the mold width direction DA. A coil spring 56 as a biasing member is provided.

Here, when the first bending block 38 moves downward against the biasing force of the plurality of coil springs 42, the cam block 50 resists the biasing force of the plurality of coil springs 56 and the other in the mold width direction DA. Move to the side (backward). Then, the second bending block 44 moves upward against the urging force of the plurality of coil springs 48. On the other hand, when the first bending block 38 moves upward by the urging forces of the plurality of coil springs 42, the cam block 50 moves to one side (forward direction) in the mold width direction DA by the urging forces of the plurality of coil springs 56. To do. Then, the second bending block 44 moves downward by the gravity and the urging forces of the plurality of coil springs 48. In other words, the second bending block 44 is configured to move in the direction opposite to the moving direction of the first bending block 38 in conjunction with the vertical movement of the first bending block 38.

At the edge of the upper surface of the first bending block 38 on the back side (rear side), a recessed processing step (processing recess) 58 for allowing the tip of the punch die 18 to enter is provided in the mold length direction DB ( (Horizontal direction). In addition, a first rounded portion (first shoulder rounded portion) 38r is formed along the mold length direction DB at a corner on the back side (rear side) of the upper surface of the first bending block 38. As shown in FIG. 2, a second rounded portion (second shoulder rounded portion) 44r is formed along the mold length direction DB at the corner portion on the front side (front side) of the upper surface of the second bending block 44. ing. Instead of forming the processing step portion 58 at the edge on the back side of the upper surface of the first bending block 38, the edge portion on the front side (front side) of the upper surface of the second bending block 44, or the first bending block 38. May be formed in a portion extending between the upper surface of the second bending block 44 and the upper surface of the second bending block 44.

Subsequently, the operation of the first embodiment will be described including the bending method according to the first embodiment. Here, the bending method according to the first embodiment is a method for performing asymmetric bending on a plate-shaped workpiece (sheet metal) W by a press brake, and includes a positioning step, a first bending step, and a second bending step. Bending process.

As shown in FIG. 4A, the workpiece W is positioned with respect to the die mold 24 so that the portion S ′ corresponding to the bending line in the workpiece W is positioned above the machining step portion 58 (positioning step). ). After the positioning step, as shown in FIGS. 1 and 4B, the punch die 18 is moved downward by the lowering operation (downward movement operation) of the upper table 12, and the punch die is moved. 18 tip portions enter the processing step portion 58. Thus, one side (front side portion) of the portion S ′ corresponding to the bending line in the workpiece W is sandwiched between the first punch tip surface 18f of the punch die 18 and the first rounded portion 38r of the first bending block 38. It is bent to the first bending angle θ1. At the same time, the other side (rear part) of the portion S ′ corresponding to the bending line in the workpiece W is sandwiched by the second punch tip surface 18s of the punch die 18 and the second rounded portion 44r of the second bending block 44. It is bent to 1 bending angle θ1. In other words, both sides (front side portion and rear side portion) of the portion S ′ corresponding to the bending line in the workpiece W can be bent at the same bending angle (first bending angle θ1) (first bending step).

As shown in FIGS. 1 and 5A and 5B, after the first bending step, the punch die 18 is further moved downward by the lowering operation of the upper table 12, and the first bending block 38 is moved. It is moved downward against the urging force of the plurality of coil springs 42. Then, the second bending block 44 is moved upward against the urging force of the plurality of coil springs 48 and protrudes upward with respect to the upper surface of the first bending block 38. As a result, the distance between the tip edge 18t of the punch die 18 and the second rounded portion 44r of the second bending block 44 is increased, and the second punch leading end surface 18s of the punch die 18 and the second bending block 44 second The other side (rear part) of the portion S ′ corresponding to the bending line in the workpiece W is sandwiched by the two rounded portions 44r and bent from the first bending angle θ to the second bending angle θ2. In other words, both sides (front side portion and rear side portion) of the portion corresponding to the bending line in the workpiece W can be bent at different bending angles (first bending angle θ1 and second bending angle θ2) (second bending step). ).

After completion of the second bending step, the punch die 18 is moved upward by the upward movement (upward movement movement) of the upper table 12, and the first bending block 38 is moved upward by the urging forces of the plurality of coil springs 42. Moved in the direction. Then, the second bending block 44 is moved downward by the gravity and the urging forces of the plurality of coil springs 48. Thereby, the die mold 24, in other words, the mold set 10 can be returned to the original state.

Here, as shown in FIG. 5B, the horizontal component F2h of the bending load F2 acting on the second round portion 44r of the second bending block 44 is the bending load acting on the first round portion 38r of the first bending block 38. Compared to the horizontal component F1h of F1, it tends to increase according to the difference between the second bending angle θ2 and the first bending angle θ1. On the other hand, when the other side (rear part) of the part S ′ corresponding to the bending line in the workpiece W is bent from the first bending angle θ1 to the second bending angle θ2, the leading edge 18t of the punch die 18 and the second bending Since the distance between the block 44 and the second rounded portion 44r is increased, the horizontal component F2h of the bending load F2 acting on the second rounded portion 44r of the second bending block 44 can be reduced. Therefore, the thrust load (the load in the front-rear direction) acting on the mold set 10 and the press brake is reduced when the workpiece W is asymmetrically bent without providing the die mold 24 with a punch receiving member made of urethane. be able to.

Then, as shown in FIG. 6, the workpiece W is bent a plurality of times to reduce bending of the workpiece W on the front side (front side) of the press brake, while deeply bending the product M from the workpiece W. Can be produced.

Therefore, according to the first embodiment, as described above, the thrust load when performing asymmetric bending on the workpiece W can be reduced without providing the die mold 24 with a punch receiving member made of urethane. . Therefore, according to the first embodiment, when asymmetric bending is performed on the workpiece W by a press brake, the processing range (processing conditions such as the thickness, material, and bending length of the workpiece W is maintained while maintaining the bending accuracy. ) Can be expanded.

(Second Embodiment)
As shown in FIGS. 7 and 8, the asymmetric bending die set 60 according to the second embodiment includes the intermediate plate 14 and the mounting bolt 16 at the lower end of the upper table 12 (only part of which is shown) in the press brake. And a punch die 18 that can be attached and detached, and a die die 62 for asymmetric bending that can be attached and detached via a lower die holder 22 at the upper end of a lower table 20 (only part of which is shown) in the press brake. In other words, the asymmetric bending mold set 60 according to the second embodiment is replaced with the asymmetric bending die mold 24 (see FIGS. 1 and 2) according to the first embodiment. The die mold 62 for asymmetric bending according to the above is used.

Subsequently, the configuration of the die mold 62 for asymmetric bending according to the second embodiment will be specifically described.

As shown in FIGS. 7 to 9A and 9B, the die mold 62 for asymmetric bending is a die mold base that can be attached to and detached from the upper end portion of the lower table 20 via a plurality of lower mold holders 22. 64, and the die mold base 64 extends in the mold length direction DB (left-right direction). The die mold base 64 has an accommodation recess 66 extending in the mold length direction DB on the upper side (upper side) thereof, and both sides of the accommodation recess 66 in the mold length direction DB are opened. .

In the receiving recess 66 of the die mold base 64, one side (front part) of the portion S corresponding to the bending line in the workpiece W cooperates with the first punch tip surface 18 f of the punch die 18 at the first bending angle. A first bending block 68 for bending to θ1 is provided. The first bending block 68 extends in the mold length direction DB (left-right direction), and is configured to be movable in the up-down direction via a plurality of guide bolts 70. In other words, the first concave block 68 extending in the mold length direction DB is provided in the housing recess 66 of the die mold base 64 so as to be movable in the vertical direction via the plurality of guide bolts 70. Each guide bolt 70 is supported in a long hole 64h formed in the upper part of the die mold base 64 so as to be movable in the vertical direction.

A coil spring 72 is provided via a set screw 74 as a biasing member for biasing the first bending block 68 upward in the support hole 64b formed at the bottom of each elongated hole 64h in the die mold base body 30. ing. Instead of using the coil spring 72 as the urging member, a gas spring (not shown) or a hydraulic cylinder (not shown) may be used.

On the back side (rear side) of the first bending block 68 in the housing recess 66 of the die mold base 64, a portion corresponding to the bending line in the workpiece W in cooperation with the second punch tip surface 18 s of the punch mold 18. A second bending block 76 for bending the other side (rear portion) of S to the second bending angle θ2 is provided. The second bending block 76 is detachably fixed to the die mold base 64 via a plurality of mounting bolts 78 (only one is shown).

At the front side (front side) edge of the upper surface of the second bending block 76, a recessed processing step (processing recess) 80 for allowing the tip of the punch die 18 to enter is provided along the mold length direction DB. Is formed. Further, a first rounded portion (first shoulder rounded portion) 68r is formed along the mold length direction DB at a corner on the back side (rear side) of the upper surface of the first bending block 68. A second rounded portion (second shoulder rounded portion) 76r is formed along the mold length direction DB at a corner portion on the front side (front side) of the upper surface of the second bending block 76. Instead of forming the processing step 80 on the front edge of the upper surface of the second bending block 38, the rear edge (rear) edge of the upper surface of the first bending block 68, or the first bending block. 68 may be formed in a portion extending from the upper surface of 68 to the upper surface of the second bending block 76.

Subsequently, the operation of the second embodiment of the present invention will be described including the bending method according to the second embodiment of the present invention. Here, the bending method according to the second embodiment of the present invention is a method for performing asymmetric bending on a plate-shaped workpiece (sheet metal) W by a press brake, and includes a positioning step, a first bending step, And a second bending step.

As shown in FIG. 10A, the workpiece W is positioned with respect to the die mold 62 so that the portion S ′ corresponding to the bending line in the workpiece W is located above the machining step 80 (positioning step). . After the positioning step, as shown in FIGS. 7 and 10B, the punch die 18 is moved downward by the lowering operation (downward movement operation) of the upper table 12, and the punch die is moved. 18 tip portions enter the processing step portion 80. Thereby, one side (front side portion) of the portion S ′ corresponding to the bending line in the workpiece W is sandwiched between the first punch tip surface 18 f of the punch die 18 and the first rounded portion 68 r of the first bending block 68. It can be bent up to one bending angle θ1. At the same time, the other side (rear part) of the portion S ′ corresponding to the bending line in the workpiece W is sandwiched by the second punch tip surface 18 s of the punch die 18 and the second rounded portion 76 r of the second bending block 76. It can be bent up to one bending angle θ1. In other words, both sides (front side portion and rear side portion) of the portion S ′ corresponding to the bending line in the workpiece W can be bent at the same bending angle (first bending angle θ1) (first bending step).

As shown in FIGS. 7 and 11 (a) and 11 (b), after the first bending step, the punch die 18 is moved further downward by the lowering operation of the upper table 12, and the first bending block 68 is moved. It is moved downward against the urging force of the plurality of coil springs 72. Then, the second bending block 76 is moved upward with respect to the first bending block 68 and protrudes upward with respect to the upper surface of the first bending block 38. As a result, the distance between the tip edge 18t of the punch die 18 and the second rounded portion 76r of the second bending block 76 is increased, and the second punch leading end surface 18s of the punch die 18 and the second bending block 76 first. It is possible to bend from the first bending angle θ to the second bending angle θ2 by sandwiching the other side (rear side portion) of the portion S ′ corresponding to the bending line in the workpiece W with the two rounded portions 76r. In other words, both sides (front side portion and rear side portion) of the portion corresponding to the bending line in the workpiece W can be bent at different bending angles (first bending angle θ1 and second bending angle θ2) (second bending step). ).

After completion of the second bending step, the punch die 18 is moved upward by the upward movement (upward movement movement) of the upper table 12, and the first bending block 68 is moved upward by the urging forces of the plurality of coil springs 72. Moved in the direction. Accordingly, the die mold 62, in other words, the mold set 60 can be returned to the original state.

Here, as shown in FIG. 11B, the horizontal component F2h of the bending load F2 acting on the second round portion 76r of the second bending block 76 is the bending load acting on the first round portion 68r of the first bending block 68. Compared to the horizontal component F1h of F1, it tends to increase according to the difference between the second bending angle θ2 and the first bending angle θ1. On the other hand, when the other side (rear part) of the part S ′ corresponding to the bending line in the workpiece W is bent from the first bending angle θ1 to the second bending angle θ2, the leading edge 18t of the punch die 18 and the second bending Since the distance between the block 76 and the second rounded portion 76r is increased, the horizontal component F2h of the bending load F2 acting on the second rounded portion 76r of the second bending block 76 can be reduced. Therefore, the thrust load (the load in the front-rear direction) acting on the mold set 10 and the press brake is reduced when the workpiece W is asymmetrically bent without providing the die mold 62 with a punch receiving member made of urethane. be able to.

Then, as shown in FIG. 12, by performing asymmetric bending a plurality of times on the workpiece W, the bending of the deep bent product M from the workpiece W is reduced while reducing the jumping of the workpiece W on the front side (front side) of the press brake. Can be produced.

Therefore, according to the second embodiment, the same effects as those of the first embodiment described above can be obtained.

It should be noted that the present invention is not limited to the description of the above-described embodiment, and can be implemented in various other modes by making various modifications. The scope of rights encompassed by the present invention is not limited to the above-described embodiment.

According to the present invention, when asymmetric bending is performed on the workpiece by the press brake, the processing range (processing conditions) such as the thickness, material, and bending length of the workpiece is expanded while maintaining the bending accuracy. Can do.

Claims (7)

In the die mold for asymmetric bending used when asymmetric bending is performed on the workpiece by press brake,
A die mold base having an accommodating recess at the top;
A first portion smaller than 45 ° is provided on one side of the portion corresponding to the bending line in the workpiece in cooperation with the punch die for asymmetric bending, provided in the receiving recess of the die mold base so as to be movable in the vertical direction. A first bending block for bending to a bending angle;
A biasing member that biases the first bending block upward;
A second side that is provided on the back side of the first bending block in the receiving recess of the die mold base and that corresponds to the bending line of the workpiece in cooperation with the punch mold is larger than 45 °. A second bending block for bending to a bending angle,
The edge on the back side of the upper surface of the first bending block, the edge on the front side of the upper surface of the second bending block, or a portion extending between the upper surface of the first bending block and the upper surface of the second bending block, A die mold for asymmetric bending, characterized in that a recessed processing step for allowing the tip of the punch mold to enter is formed. 2. The asymmetric bending device according to claim 1, wherein the second bending block is configured to move in a direction opposite to a movement direction of the first bending block in conjunction with a vertical movement of the first bending block. Die mold. A first sliding contact surface inclined with respect to a vertical direction is formed at a lower portion of the first bending block, and a second sliding contact surface inclined with respect to the vertical direction is formed at a lower portion of the second bending block;
A first cam surface slidably contacting the first slidable contact surface of the first bending block is formed on one side in the mold width direction of the upper portion, and the second bending block of the second bending block is formed on the other side in the mold width direction of the upper portion. The cam block having a second cam surface formed in sliding contact with the second sliding contact surface is provided on the bottom side of the receiving recess of the die mold base so as to be movable in the mold width direction. Item 3. A die for asymmetric bending according to Item 2. The die mold for asymmetric bending according to claim 1, wherein the second bending block is fixed to the die mold base. A first rounded portion is formed at a corner on the back side of the top surface of the first bending block, and a second rounded portion is formed at a corner on the front side of the top surface of the second bending block. The die mold for asymmetric bending according to any one of claims 1 to 4. In a mold set for asymmetric bending used when asymmetric bending is performed on a workpiece by a press brake,
The punch tip surface that is detachable from the lower end portion of the upper table in the press brake and is inclined at the same angle as the first bending angle smaller than 45 ° with respect to the horizontal direction passing through the tip edge on the front side of the tip portion. A punch mold for asymmetric bending formed with
It is detachable with respect to the upper end part of the lower table in the press brake, and comprises a die mold for asymmetric bending according to any one of claims 1 to 5. Mold set for asymmetric bending. In the bending method for performing asymmetric bending on the workpiece by press brake,
While using a punch die for asymmetric bending formed with a punch tip surface inclined by the same angle as the first bending angle smaller than 45 ° with respect to the horizontal direction passing through the tip edge on the front side of the tip portion,
A die mold base having a housing recess in the upper portion; a first bending block provided in the housing recess of the die mold base so as to be movable in a vertical direction; and the first in the housing recess of the die mold base. A second bending block provided on the back side of the first bending block, a rear side edge of the upper surface of the first bending block, a front side edge of the upper surface of the second bending block, or the first Using a die mold for asymmetric bending in which a recessed stepped portion is formed in a portion spanning the upper surface of the bending block and the upper surface of the second bending block,
With the portion corresponding to the bending line in the workpiece positioned on the upper side of the machining step, the punch die is moved downward, and the tip of the punch die enters the machining step. By sandwiching one side of the part corresponding to the bending line in the workpiece by the corners on the back side of the punch tip surface of the punch mold and the upper surface of the first bending block, and bending to the first bending angle, A first bending step of bending the other side of the part corresponding to the bending line in the workpiece to a first bending angle by a corner on the front side of the upper surface of the second bending block;
By further moving the punch mold downward, moving the first bending block downward, and projecting the second bending block upward with respect to the upper surface of the first bending block, While increasing the distance between the front edge of the punch die and the front corner on the upper surface of the second bending block, the front corner corresponds to the bending line in the workpiece by the upper corner of the second bending block. And a second bending step of bending the other side of the portion from the first bending angle to a second bending angle larger than 45 °.

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