Press machine

Abstract

To properly support a rear part of a workpiece with a simple constitution.SOLUTION: A press machine 1 that processes a plate-shaped workpiece W by holding it between an upper die 7 and a lower die 4, includes: a back gauge 10 which positions the workpiece W in a longitudinal direction R2 by being butted with a rear-side end part Wa of the workpiece W arranged on the lower die 4, where the longitudinal direction R2 is a direction orthogonal to a lateral direction R1 on a horizontal plane; a garter 20 supporting the back gauge 10, the garter 20 being provided in the form of a rod extending in the lateral direction R1 and movable in at least the longitudinal direction R2; and a workpiece receiver 40 provided in the form of a shape extending in the longitudinal direction R2 so as to receive a work rear part Wb of the workpiece W arranged on the lower die 4 from below, a front side part 42 of the work receiver 40 being supported by a front-side support part 50 and a rear side part 60 being mounted on a garter 20.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a press machine.

Background Art

[0002] As one type of press machine, a press brake (bending machine) that performs bending processing on a plate-shaped workpiece is known. In a press brake, a workpiece is processed by clamping the workpiece between an upper die and a lower die that extend in the left-right direction. In a press brake, the workpiece is positioned on the lower die by abutting the workpiece against a back gauge disposed behind the lower die. At this time, a workpiece receiver is provided to receive and support the rear portion of the workpiece (rear workpiece portion) from below between the lower die and the back gauge (see, for example, Patent Document 1).

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] The press machine of Patent Document 1 is provided with a plurality of workpiece receivers arranged in the front-rear direction between the lower die and the back gauge. Each of the plurality of workpiece receivers is provided to be capable of lifting and lowering, and by selectively lifting and lowering the plurality of workpiece receivers, the arrangement corresponds to the arrangement position of the back gauge, that is, the length of the rear workpiece portion rearward from the lower die. In such a configuration using a plurality of workpiece receivers, since the plurality of workpiece receivers are selectively lifted and lowered according to the back gauge, control becomes complicated and the load imposed on the control device increases. In addition, in a configuration where workpiece receivers are arranged at intervals in the front-rear direction as in Patent Document 1, the rear workpiece portion is supported intermittently, and there are portions where the workpiece is not supported, resulting in the problem that the rear workpiece portion may not be properly supported in some cases.

[0005] The present invention aims to provide a press machine that can properly support the rear portion of a workpiece with a simple configuration. [Means for solving the problem]

[0006] A press machine according to an aspect of the present invention is a press machine that processes a plate-shaped workpiece by sandwiching it between an upper die and a lower die extending in the left-right direction, comprising: a back gauge that positions the workpiece in the front-rear direction by abutting the rear end of the workpiece placed on the lower die, with the front-rear direction being the direction perpendicular to the left-right direction on a horizontal plane; a girder that supports the back gauge and is provided in the left-right direction and is at least movable in the front-rear direction; and a workpiece holder that is provided in the front-rear direction and is plate-shaped so as to receive the rear part of the workpiece placed on the lower die from below, with the front part being supported by a front support and the rear part resting on the girder. [Effects of the Invention]

[0007] In the press machine according to the above embodiment, the rear portion of a plate-shaped workpiece support extending in the front-rear direction is placed on the girder. Therefore, the girder can move in the front-rear direction with the workpiece support on it. As a result, when moving the back gauge in the front-rear direction, it is only necessary to move the girder in the front-rear direction, making it easier to control the position of the back gauge compared to selectively raising and lowering multiple workpiece supports. In other words, the rear portion of the workpiece can be appropriately supported with a simple configuration. Furthermore, because the workpiece support extends in the front-rear direction, the rear portion of the workpiece can be stably supported, and the workpiece can be appropriately positioned.

[0008] Furthermore, in the press machine according to the above embodiment, a rear support portion on which the rear portion of the workpiece receiver can be placed is provided, and the front support portion is fixed to the front portion of the workpiece receiver. The front support portion and the rear support portion are each provided to be able to move up and down, and the workpiece receiver may be lowered by lowering the front support portion and the rear support portion. With this configuration, since the rear portion of the workpiece receiver is placed on the rear support portion, it is possible to prevent the workpiece receiver from bending downward. Furthermore, by lowering the front support portion and the rear support portion, the workpiece receiver can be easily lowered. In addition, in the press machine according to the above embodiment, the rear support portion may be able to move away from the workpiece receiver and retract below the movement path of the girder when the girder moves forward. With this configuration, it is possible to prevent interference between the girder and the support portion by retracting the rear support portion downward.

[0009] Furthermore, in the press machine according to the above embodiment, the front portion of the workpiece holder may bend when the front support portion descends and comes into contact with a part of the main frame of the press machine. With this configuration, if the front end of the workpiece holder is positioned near the lower die, the front portion of the workpiece holder will come into contact with the main frame of the press machine when the workpiece holder is descended, preventing it from descending. However, by making the front portion of the workpiece holder bendable, the workpiece holder can be lowered appropriately. In addition, in the press machine according to the above embodiment, the front support portion may be equipped with an elastic member that returns the front portion of the workpiece holder from a bent state to a straight state. With this configuration, when the workpiece holder is raised, the elastic member of the workpiece holder can appropriately return it to a state extended in the front-rear direction.

[0010] Furthermore, in the press machine according to the above embodiment, the girder may be movable backward to a position where the workpiece support is detached, and with the workpiece support detached, the front and rear support parts may be lowered to lower the workpiece support, thereby allowing the girder to move forward above the workpiece support. With this configuration, when the workpiece support is not needed, such as when the back gauge is placed near the lower die, the front and rear support parts may be lowered to lower the workpiece support, allowing the girder to move forward above the workpiece support. Also, in the press machine according to the above embodiment, the movement of the girder forward may be restricted when the rear support part is raised. With this configuration, interference with the rear support part can be prevented when the girder moves forward.

[0011] Furthermore, in the press machine according to the above embodiment, multiple work supporters may be arranged with spacing between them in the left-right direction. With this configuration, workpieces that are wide in the left-right direction can be appropriately supported by multiple work supporters. Furthermore, in the press machine according to the above embodiment, the girder may be provided with a guide portion that extends in the left-right direction, and the back gauge may be movable in the left-right direction along the guide portion. With this configuration, the left-right position of the back gauge can be easily changed. Furthermore, in the press machine according to the above embodiment, the girder may be provided so as to be able to move up and down, and the height of the back gauge relative to the lower die can be changed. With this configuration, the height of the back gauge can be easily changed by moving the girder up and down. [Brief explanation of the drawing]

[0012] [Figure 1] This is a front view showing an example of a press machine according to the embodiment. [Figure 2] This is a perspective view showing the main parts of a press machine according to an embodiment. [Figure 3] This is a side view showing the rear portion of the workpiece holder placed on the girder. [Figure 4] This is a perspective view showing the girder in a forward position. [Figure 5] This is a side view showing the girder in a forward position. [Figure 6] This is a perspective view showing the rear portion of the workpiece support placed on the girder and rear support. [Figure 7] This is a side view showing the rear portion of the workpiece support placed on the girder and rear support. [Figure 8] This is a side view showing the workpiece holder with the girder removed. [Figure 9] This is a perspective view showing the work support in a lowered state. [Figure 10] This is a side view showing the workpiece support in its lowered position. [Figure 11] This is a perspective view showing the girder in a forward position. [Figure 12] This is a perspective view showing the girder in a forward position. [Modes for carrying out the invention]

[0013] The embodiments will be described below with reference to the drawings. However, the present invention is not limited to what is described below. Also, in order to illustrate the embodiments, the scale has been appropriately changed in the drawings, such as by enlarging or emphasizing some parts, and the shape, dimensions, etc. may differ from the actual product. In each of the following figures, the directions in the figures will be explained using the XYZ coordinate system. In this XYZ coordinate system, the plane parallel to the horizontal plane is called the XY plane. In this XY plane, one direction is denoted as such, and the direction perpendicular to the X direction is called the Y direction. Also, the direction perpendicular to the XY plane is called the Z direction. In the X, Y, and Z directions, the direction pointed to by the arrow in the figure is the + direction, and the direction opposite to the direction pointed to by the arrow is called the - direction. The left-right direction R1 is parallel to the X direction, with the -X side being the right side and the +X side being the left side. The front-back direction R2 is parallel to the Y direction, with the -Y side being the front side and the +Y side being the rear side.

[0014] Figure 1 is a front view showing an example of a press machine 1 according to an embodiment. In Figure 1, a view of the press machine 1 as viewed from the front side (-Y side) is shown. In the present embodiment, the press machine 1 is a press brake (bending machine) capable of performing bending processing (forming processing) on a workpiece W. In the press machine 1, the front side (-Y side) serves as an operator's working space. An operator places the workpiece W at a predetermined position from the front side of the press machine 1, and bends the workpiece W by clamping the workpiece W between an upper die 7 and a lower die 4, which will be described later. As shown in Figure 1, the press machine 1 includes a main body frame 2 and a ram 3.

[0015] The main body frame 2 is formed including a table 2A, side frames 2B, and a beam portion 2C, and forms the outer shell of the press machine 1. The table 2A supports the lower die 4 on the upper surface side. The lower die 4 is, for example, a fixed-side die, and is formed to be long along the left-right direction R1 (X direction). The lower die 4 is supported by the table 2A via a lower die holder 5. The lower die 4 has a V-shaped recess 4a on its upper surface for bending the workpiece W. This recess 4a is formed continuously along the left-right direction R1. The table 2A is also provided with a back gauge 10 for butting the workpiece W in the +Y direction for positioning. The details of the back gauge 10 will be described later.

[0016] The side frames 2B are respectively provided on the side portions of the main body frame 2 in the left-right direction R1. The side frames 2B support a lifting device 6. The lifting device 6 moves (lifts and lowers) the ram 3 in the Z direction. For the lifting device 6, for example, a ball screw mechanism using an electric motor or the like, a hydraulic cylinder device, a pneumatic cylinder device, or the like is used. The ram 3 is supported so as to be able to lift and lower relative to the main body frame 2 by a guide portion (not shown) provided on the side frame 2B. The ram 3 is arranged in a state suspended from a part of the lifting device 6. The ram 3 is lifted and lowered by driving the lifting device 6, and approaches or separates from the lower die 4 on the table 2A.

[0017] An upper die 7 is held below the ram 3. The upper die 7 is held on the ram 3 via a plurality of upper die holders attached to the ram 3. The plurality of upper die holders 8 are arranged along the left-right direction R1 and are detachable from the ram 3. The interval between adjacent ones of the plurality of upper die holders 8 can be arbitrarily set. Each of the plurality of upper die holders 8 can hold an upper die 7 respectively. For example, when bending a workpiece W, the plurality of upper die holders 8 hold upper dies 7 corresponding to respective steps of the bending process.

[0018] When held by the upper die holder 8, the upper die 7 faces above the lower die 4, and the lower end of the upper die 7 is arranged along the left-right direction R1. Further, the lower end of the upper die 7 has a tip portion 7a that enters the recess 4a of the lower die 4. The upper die 7 moves up and down integrally with the ram 3 and the upper die holder 8. In the press machine 1, as the ram 3 descends, the upper die 7 moves toward the lower die 4, the workpiece W is sandwiched between the upper die 7 and the lower die 4, and bending is performed on the workpiece W before the upper die 7 reaches the lowest point.

[0019] The press machine 1 includes a control unit 9. The control unit 9 integrally controls the press machine 1. The control unit 9 controls the lifting operation of the ram 3 based on commands sent from a host control device or the like, or commands input by an operator or the like. Further, based on a command for the arrangement position of the back gauge 10, the control unit 9 controls the movement and lifting of a garter 20 (described later) in the front-rear direction R2, the position of a slider 30 (described later) in the left-right direction R1, and the lifting operation of a front support portion 50 and a rear support portion 60 (described later).

[0020] Figure 2 is a perspective view showing essential parts of the press machine 1 according to the embodiment. Figure 3 is a side view showing a state where a rear portion 41 of a workpiece receiver 40 is placed on the garter 20. Figure 3 is a view of the essential parts of the press machine 1 shown in Figure 2 as viewed from the -X side. As shown in Figure 2 and Figure 3, the press machine 1 includes the above-mentioned back gauge 10, the garter 20, the slider 30, the workpiece receiver 40, the front support portion 50, and the rear support portion 60.

[0021] The back gauge 10 abuts against the rear end Wa (see Figure 3) of the workpiece W placed on the lower die 4, positioning the workpiece W in the front-rear direction R2. Multiple back gauges 10 are provided along the left-right direction R1. In this embodiment, the back gauges 10 are provided at two locations spaced apart in the left-right direction R1. However, the number of back gauges 10 is arbitrary. One or three or more back gauges 10 may be provided. The back gauges 10 are supported on the upper surface 23 side of the girder 20 via the slider 30. In a plan view, the back gauges 10 are positioned so as to protrude forward (-Y side) of the girder 20.

[0022] The girder 20 is provided in the shape of a rod extending in the left-right direction R1. The girder 20 is supported on the main frame 2 (see Figure 1) by a guide part (not shown) so that it can move up and down in the front-rear direction R2 and the up-down direction (Z direction). The girder 20 moves in the front-rear direction R2 by driving the front-rear drive unit 21 (see Figure 3). The girder 20 moves in the front-rear direction R2 while maintaining its state of extending in the left-right direction R1 due to the front-rear drive unit 21.

[0023] Furthermore, the girder 20 moves up and down by driving the lifting drive unit 22 (see Figure 3). The girder 20 moves up and down while maintaining its position extending in the left-right direction R1 by the lifting drive unit 22. As described above, the girder 20 supports the back gauge 10 via the slider 30. The girder 20 is provided with a guide portion 24 on its upper surface 23. The guide portion 24 is provided on the upper surface 23 of the girder 20, extending in the left-right direction R1.

[0024] The slider 30 is positioned on the upper surface 23 of the girder 20. The slider 30 includes a support portion 31 and a projection 32. The back gauge 10 is fixed to the support portion 31. By being fixed to the support portion 31, the back gauge 10 is held in a state that protrudes forward from the girder 20. The projection 32 is positioned to fit into the guide portion 24 of the girder 20. The slider 30 is movable in the left-right direction R1 as the projection 32 is guided by the guide portion 24. In other words, the back gauge 10 is movable in the left-right direction R1 relative to the girder 20.

[0025] The slider 30 moves in the left-right direction R1 by driving a drive unit (not shown). Therefore, by moving the slider 30 in the left-right direction R1, the back gauge 10 can be moved to any position in the left-right direction R1. The girder 20 is controlled to a predetermined height by the lifting drive unit 22. For example, the height of the girder 20 (height of the back gauge 10) is controlled by the lifting drive unit 22 so that the end Wa of the workpiece W on the workpiece holder 40 contacts the back gauge 10.

[0026] The work support 40 is provided in a plate shape that extends in the front-rear direction R2 so as to support the rear portion Wb of the workpiece W placed on the lower die 4 from below. The work support 40 is provided so as to extend from near the rear side of the lower die 4 toward the rear (+Y direction). Multiple work support 40s are provided in parallel with a gap between them in the left-right direction R1. Multiple work support 40s are used and have the same shape, but are not limited to this configuration, and the shapes of the multiple work support 40s may differ from each other, such as some of the multiple work support 40s having different widths in the left-right direction R1.

[0027] The workpiece holder 40 is plate-shaped and comprises a rear portion 41, a front portion 42, and a hinge portion 43. The front portion 42 is supported by a front support portion 50. The portion of the front portion 42 rearward from the hinge portion 43 is fixed to the front support portion 50. The rear portion 41 rests on the upper surface 23 of the girder 20. The hinge portion 43 connects the rear portion 41 and the front portion 42. This hinge portion 43 allows the front portion 42 to rotate around a horizontal axis relative to the rear portion 41. In other words, the workpiece holder 40 is foldable relative to the rear portion 41. Furthermore, the workpiece holder 40 can be positioned so that the rear portion 41 is removed from the upper surface 23 of the girder 20 by moving the girder 20 backward (+Y direction).

[0028] The front support section 50 is supported by a frame 2D, which is part of the main frame 2. The front support section 50 is positioned below the front portion 42 of the workpiece holder 40. The front support section 50 comprises a lifting drive unit 51, a lifting rod 52, a receiving section 53, and an elastic member 54. The lifting drive unit 51 raises and lowers the lifting rod 52. For example, a cylinder device using pneumatics or hydraulics, an electric motor, etc., can be used as the lifting drive unit 51. The operation of the lifting drive unit 51 is controlled by the control unit 9. The lifting rod 52 is provided to protrude upward from the lifting drive unit 51. The lifting rod 52 moves up and down by driving the lifting drive unit 51.

[0029] The receiving portion 53 is fixed to the upper end of the lifting rod 52. The receiving portion 53 moves up and down as the lifting rod 52 moves up and down. The raised position of the receiving portion 53 is set, for example, by defining the raised position of the lifting rod 52 using a stopper provided on the lifting drive unit 51. The lowered position (retracted position) of the receiving portion 53 is set to a position where it does not interfere with the girder 20 when the girder 20 moves forward. The portion of the front part 42 of the workpiece holder 40 that is rearward from the hinge portion 43 is fixed to the upper surface of the receiving portion 53. Therefore, as the receiving portion 53 moves up and down, the front part 42 of the workpiece holder 40 also moves up and down as a whole.

[0030] The elastic member 54 is provided on the receiving portion 53. The elastic member 54 applies an elastic force to the front portion 42 so that it faces horizontally. Therefore, when the front portion 42 bends upward around the hinge portion 43, it bends against the elastic force of the elastic member 54. Also, when the front portion 42 is released from the bent state, the front portion 42 returns to a horizontal position due to the elastic member 54. In other words, the elastic member 54 returns the bent workpiece support 40 to a straight position. For example, a coil spring can be used as the elastic member 54.

[0031] The rear support section 60, like the front support section 50, is supported by a frame 2D, which is part of the main frame 2. The rear support section 60 is positioned below the rear portion 41 of the workpiece holder 40. Therefore, the front support section 50 and the rear support section 60 are positioned side by side in the front-rear direction R2 on the rear side of the table 2A. The rear support section 60 includes a lifting drive unit 61, a lifting rod 62, and a receiving section 63. The lifting drive unit 61 raises and lowers the lifting rod 62. For example, a cylinder device using pneumatics or hydraulics, an electric motor, etc., can be used as the lifting drive unit 61. The operation of the lifting drive unit 61 is controlled by the control unit 9. The lifting rod 62 is provided to protrude upward from the lifting drive unit 61. The lifting rod 62 moves up and down by driving the lifting drive unit 61.

[0032] The receiving portion 63 is fixed to the upper end of the lifting rod 62. The receiving portion 63 moves up and down as the lifting rod 52 moves up and down. The raised position of the receiving portion 63 is set by defining the raised position of the lifting rod 62, for example, by a stopper provided on the lifting drive unit 61. The lowered position (retracted position) of the receiving portion 63 is set to a position where it does not interfere with the girder 20 when the girder 20 moves forward. The upper surface of the receiving portion 63 can support the rear portion 41 of the workpiece holder 40. Therefore, when the rear portion 41 of the workpiece holder 40 is supported on the girder 20, the receiving portion 63 will move away from the rear portion 41. In other words, the receiving portion 63 can move away from the workpiece holder 40 and retract to below the movement path of the girder 20 in the front-rear direction R2.

[0033] Furthermore, when the girder 20 moves backward and detaches from the workpiece holder 40, the workpiece holder 40 is supported by both the front support portion 50 and the rear support portion 60. In this state, by driving the lifting drive unit 51 of the front support portion 50 and the lifting drive unit 61 of the rear support portion 60 to raise and lower the receiving portion 53 and the receiving portion 63, the workpiece holder 40 also moves up and down together with the receiving portion 53 and the receiving portion 63. In other words, by lowering the receiving portion 53 and the receiving portion 63, the workpiece holder 40 can be lowered. At this time, the receiving portion 53 and the receiving portion 63 have lowered to a position where they do not interfere with the movement of the girder 20 in the front-rear direction R2, and the workpiece holder 40 has also moved out of the path of movement of the girder 20 in the front-rear direction R2.

[0034] With the workpiece support 40 (supporting portion 53 and supporting portion 63) in a lowered position, the girder 20 can move forward above the workpiece support 40 by the front-rear drive unit 21. In this case, the workpiece W placed on the lower die 4 is not in contact with the workpiece support 40. The press machine 1 of this embodiment can be used in a configuration in which the workpiece W is supported from below using the workpiece support 40 and the back gauge 10 is used, or in a configuration in which the back gauge 10 is used without the workpiece support 40.

[0035] Furthermore, the control unit 9 may restrict the forward movement of the girder 20 when the rear support portion 60 is raised. For example, the control unit 9 may control the front-rear drive unit 21 so as not to move the girder 20 forward unless it receives a signal from the rear support portion 60 indicating that the receiving portion 63 is in the retracted position. This configuration prevents interference between the girder 20 and the rear support portion 60 when the girder 20 moves forward.

[0036] Next, the operation of the press machine 1 according to this embodiment will be described. First, the case where the rear portion Wb of the workpiece is long will be described. In this specification, the rear portion Wb of the workpiece is used to mean the portion from the lower die 4 to the rear end Wa when the workpiece W is placed on the lower die 4. The front portion Wc of the workpiece is used to mean the portion in front of the lower die 4 when the workpiece W is placed on the lower die 4. As shown in Figures 2 and 3, when the rear portion Wb of the workpiece is long, the back gauge 10 is positioned far away from the lower die 4 on the +Y side.

[0037] The control unit 9 moves the slider 30 in the left-right direction R1 so that the end Wa of the workpiece W contacts the two back gauges 10 when the girder 20 is detached from the workpiece holder 40. The position of the slider 30 (back gauges 10) in the left-right direction R1 is set so that the slider 30 does not interfere with the workpiece holder 40. At this time, the workpiece holder 40 is supported by both the front support portion 50 and the rear support portion 60. Next, the control unit 9 drives the front-rear drive portion 21 and the lifting drive portion 22 to move and lift the girder 20, positioning the girder 20 below the rear portion 41 of the workpiece holder 40. In this state, the back gauges 10 protrude above the workpiece holder 40.

[0038] Furthermore, when moving the slider 30 in the left-right direction R1, the girder 20 may be raised by the lifting drive unit 22 when the girder 20 is detached from the workpiece holder 40. In other words, even when the girder 20 is detached from the workpiece holder 40, a part of the slider 30 may interfere with the rear part 41 of the workpiece holder 40 when the slider 30 moves in the left-right direction R1. For this reason, the girder 20 may be raised further when the girder 20 is detached from the workpiece holder 40 to avoid interference between the slider 30 and the workpiece holder 40 when the slider 30 moves in the left-right direction R1.

[0039] Each of the multiple workpiece holders 40 has its front portion 42 positioned near the rear of the lower die 4 by the raised support portion 53, and its rear portion 41 resting on the girder 20. The height of the upper surface of the workpiece holder 40 is set to be the same as or approximately the same as the height of the recess 4a at the upper end of the lower die 4. The rear support portion 60 may either lower the support portion 63 or raise the support portion 63 to support the workpiece holder 40. Supporting the workpiece holder 40 with the support portion 63 of the rear support portion 60 prevents the workpiece holder 40 from bending downward (increasing the rigidity of the workpiece holder 40). The slider 30 (back gauge 10) is positioned between the multiple workpiece holders 40 in the left-right direction R1.

[0040] The operator holds the front part Wc of the workpiece, places the workpiece W on the lower die 4, and inserts it backward, abutting the end Wa of the workpiece W against the back gauge 10. At this time, the rear part Wb of the workpiece slides backward on the workpiece support 40. As a result, the rear part Wb of the workpiece is prevented from bending downward, and the end Wa of the workpiece W can be easily and accurately abutted against the back gauge 10. While maintaining this state, the operator instructs the control unit 9 to perform the bending process. The control unit 9 drives the lifting device 6 (see Figure 1) to lower the ram 3 (see Figure 1). The workpiece W is bent by being sandwiched between the lower die 4 and the upper die 7. Since the rear part Wb of the workpiece is supported by the workpiece support 40, the bending process of the workpiece W can be performed appropriately.

[0041] Next, we will describe the case where the rear portion Wb of the workpiece is of medium size. A medium-sized rear portion Wb of the workpiece is shorter than the rear portion Wb of the workpiece shown in Figure 3, but the portion from the lower die 4 to the rear end Wa is relatively long. Figure 4 is a perspective view showing the state in which the girder 20 has moved forward. Figure 5 is a side view showing the state in which the girder 20 has moved forward. In Figures 4 and 5, the same reference numerals are used for components similar to those in the embodiments described above, and their descriptions are omitted or simplified. Also, in Figures 5 and later, the control unit 9, the front / rear drive unit 21, and the lifting / lowering drive unit 22 are omitted from the description. As shown in Figures 4 and 5, the girder 20 moves forward in the front / rear direction R2 and is positioned to correspond to the end Wa of the workpiece W of the back gauge 10.

[0042] The control unit 9 acquires information about the workpiece W to be bent and determines the length of the rear part Wb of the workpiece. First, the control unit 9 drives the lifting drive unit 61 to the rear support unit 60, lowering the receiving unit 63 and moving it out of the movement path of the girder 20. The control unit 9 maintains the raised position of the receiving unit 53 relative to the front support unit 50. As a result, the workpiece receiver 40 is maintained in a straight line extending in the front-rear direction R2 at the height shown in Figure 3.

[0043] Next, the control unit 9 drives the front and rear drive unit 21 (see Figure 3) to move the girder 20 forward, positioning the back gauge 10 to correspond to the length of the rear portion Wb of the workpiece. In this case, the rear portion 41 of the workpiece holder 40 remains on the upper surface 23 of the girder 20, and the upper surface 23 of the girder 20 slides against the lower surface of the rear portion 41. A surface treatment or film with a low coefficient of friction may be provided on either or both of the lower surface of the rear portion 41 and the upper surface 23 of the girder 20. This configuration allows for smoother operation of the girder 20 and prevents dust generation.

[0044] As described above, the operator holds the front part Wc of the workpiece, places the workpiece W on the lower die 4, inserts it backward, and abuts the end Wa of the workpiece W against the back gauge 10. The bending process is also performed by sandwiching the workpiece W between the lower die 4 and the upper die 7 after placing the workpiece W, and this is the same as described above, so the explanation is omitted. Even in the configuration shown in Figures 4 and 5, when the workpiece W is placed on the lower die 4, the rear part Wb of the workpiece is supported by the workpiece support 40, which prevents the rear part Wb from bending downward and allows the end Wa of the workpiece W to abut easily and accurately against the back gauge 10. In addition, since the rear part Wb of the workpiece is supported by the workpiece support 40, the bending process of the workpiece W can be performed appropriately.

[0045] Next, we will explain the case where the rear portion Wb of the workpiece is short. A short rear portion Wb of the workpiece refers to a case where it is even shorter than the rear portion Wb of the workpiece shown in Figure 5. Figures 6 to 12 illustrate the operation of the press machine 1 when the rear portion Wb of the workpiece is short from the state shown in Figures 4 and 5. In Figures 6 to 12, the same reference numerals are used for components similar to those in the embodiments described above, and their descriptions are omitted or simplified. Figure 6 is a perspective view showing the rear portion 41 of the workpiece holder 40 placed on the girder 20 and the rear support portion 60. Figure 7 is a side view showing the rear portion 41 of the workpiece holder 40 placed on the girder 20 and the rear support portion 60.

[0046] First, as shown in Figures 6 and 7, the girder 20 moves rearward in the front-rear direction R2. After the girder 20 moves, the rear portion 41 of the workpiece holder 40 is supported by the receiving portion 63 of the rear support portion 60. The control unit 9 drives the front-rear drive unit 21 (see Figure 3) to move the girder 20 until it is behind the rear support portion 60. Subsequently, the control unit 9 drives the lifting drive unit 61 of the rear support portion 60 to raise the receiving portion 63 and bring it into contact with the rear portion 41 of the workpiece holder 40. As a result, the rear portion 41 of the workpiece holder 40 is placed on the upper surface 23 of the girder 20 and also on the receiving portion 63.

[0047] Next, the control unit 9 moves the girder 20 further backward. Figure 8 is a side view showing the state after the girder 20 has been removed from the workpiece holder 40. As shown in Figure 8, the control unit 9 drives the front and rear drive unit 21 to move the girder 20 backward to a position where it is detached from the workpiece holder 40. As a result, a gap D is formed between the girder 20 and the workpiece holder 40. The size of the gap D can be set arbitrarily. Also, the rear portion 41 of the workpiece holder 40 is now resting on the receiving portion 63 of the rear support portion 60 because the girder 20 has been removed.

[0048] Next, the control unit 9 lowers the workpiece holder 40 using the front support section 50 and the rear support section 60. Figure 9 is a perspective view showing the workpiece holder 40 in the lowered state. Figure 10 is a side view showing the workpiece holder 40 in the lowered state. As shown in Figures 9 and 10, the control unit 9 drives the lifting drive unit 51 of the front support section 50 and the lifting drive unit 61 of the rear support section 60 to lower the receiving section 53 and the receiving section 63. For example, the control unit 9 drives the lifting drive unit 51 and the lifting drive unit 61 synchronously and controls the receiving section 53 and the receiving section 63 to lower simultaneously or almost simultaneously.

[0049] As the receiving portions 53 and 63 descend, the workpiece holder 40 descends in a linear manner in the front-rear direction R2. At this time, as described above, a gap D is formed in advance between the girder 20 and the workpiece holder 40, so that the girder 20 and the workpiece holder 40 do not interfere with each other as the workpiece holder 40 descends. When the workpiece holder 40 descends, the front portion 42 of the workpiece holder 40 hits the rear corner portion 2A1 on the upper surface of the table 2A and gradually rotates upward around the hinge portion 43. In other words, the front portion 42 hits the corner portion 2A1, which is part of the main frame 2 of the press machine 1, and bends. The rotation of the front portion 42 is in opposition to the elastic force of the elastic member 54 provided inside the receiving portion 53.

[0050] When the receiving portion 53 and the receiving portion 63 are lowered to the retracted position, the workpiece holder 40 is retracted downward from the movement path of the girder 20 in the front-rear direction R2. The front portion 42 of the workpiece holder 40 remains in contact with the table 2A (corner portion 2A1), which is part of the main frame 2, and maintains its bent state.

[0051] Next, the control unit 9 drives the front-rear drive unit 21 (see Figure 3) to move the girder 20 forward, positioning the back gauge 10 to correspond to the length of the rear part Wb of the workpiece. Figure 11 is a perspective view showing the state in which the girder 20 has moved forward. Figure 12 is a perspective view showing the state in which the girder 20 has moved forward. The girder 20 moves forward above and away from the workpiece holder 40. In other words, the girder 20 moves forward in the front-rear direction R2 without contacting the workpiece holder 40.

[0052] As described above, the operator holds the front part Wc of the workpiece, places the workpiece W on the lower die 4, inserts it backward, and abuts the end Wa of the workpiece W against the back gauge 10. The bending process is also performed by sandwiching the workpiece W between the lower die 4 and the upper die 7 after the workpiece W is placed, and this is also the same as described above, so the explanation is omitted. In the configurations shown in Figures 11 and 12, when the workpiece W is placed on the lower die 4, the rear part Wb of the workpiece is not supported by the workpiece support 40. However, since the rear part Wb of the workpiece is short, the amount by which the rear part Wb of the workpiece bends downward is extremely small, and it is easy to abut the end Wa of the workpiece W against the back gauge 10. Also, because the rear part Wb of the workpiece is short, the bending process of the workpiece W can be performed appropriately even if the rear part Wb of the workpiece is not supported by the workpiece support 40.

[0053] The case in which the workpiece support 40 is raised from the configuration shown in Figures 11 and 12 will be described. First, the control unit 9 drives the front and rear drive unit 21 to move the girder 20 backward to a position away from the workpiece support 40 (see Figure 8). Next, the control unit 9 drives the lifting drive unit 51 of the front support unit 50 and the lifting drive unit 61 of the rear support unit 60 to raise the support units 53 and 63. For example, the control unit 9 drives the lifting drive unit 51 and the lifting drive unit 61 synchronously and controls them so that the support units 53 and 63 rise simultaneously or almost simultaneously.

[0054] As the receiving portions 53 and 63 rise, the workpiece holder 40 rises. The front portion 42 of the workpiece holder 40 gradually rotates downward due to the elastic force of the elastic member 54 before it crosses the corner 2A1 of the table 2A, and returns to an extended state in the front-rear direction R2 when it crosses the corner 2A1. That is, when the workpiece holder 40 rises to the state shown in Figure 8, for example, the front portion 42 returns from a bent state relative to the rear portion 41 to a straight line extending in the front-rear direction R2. With a simple configuration such as using the elastic member 54, the bent workpiece holder 40 can be easily returned to a straight line.

[0055] As described above, in the press machine 1 of this embodiment, the rear portion 41 of the workpiece support 40, which extends in the front-rear direction R2, is placed on the girder 20. Therefore, the girder 20 can move in the front-rear direction R2 with the workpiece support 40 placed on it. As a result, when moving the back gauge 10 in the front-rear direction R2, it is only necessary to move the girder 20 in the front-rear direction R2, making it easy to control the position of the back gauge 10. In other words, the rear portion Wb of the workpiece can be appropriately supported with a simple configuration. Furthermore, since the workpiece support 40 is positioned to extend in the front-rear direction R2, the rear portion Wb of the workpiece can be stably supported, and the positioning of the workpiece W can be appropriately performed.

[0056] Although embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the embodiments described above. It will be apparent to those skilled in the art that various modifications or improvements can be made to the embodiments described above. Furthermore, such modified or improved forms are also included in the technical scope of the present invention. One or more of the requirements described in the embodiments described above may be omitted. Also, the requirements described in the embodiments described above can be combined as appropriate. In addition, the execution order of each operation shown in the embodiments can be implemented in any order, as long as the result of the previous operation is not used in the subsequent operation. Furthermore, even if the operations in the embodiments described above are described using terms such as "first," "next," and "followed by," it is not essential to perform them in this order. [Explanation of Symbols]

[0057] R1...Left and right direction R2...Anteroposterior direction W...work Wa...end Wb...Rear part of the workpiece Wc···Work front section 1. Press machine 2. Main frame 4...Lower mold 7...Top mold 10···Back gauge 20... Garter 24.. Guide Section 40...work acceptance 41...rear part 42...front part 50...Front support part 54. Elastic member 60...Rear support part

Claims

1. A press machine that processes a plate-shaped workpiece by sandwiching it between an upper die and a lower die that extend in the left-right direction, On a horizontal plane, the direction perpendicular to the left-right direction is defined as the front-back direction. A back gauge is provided, which is positioned in the front-rear direction against which the rear end of the workpiece, which is placed on the lower die, abuts. A girder is provided to support the back gauge, is provided in the shape of a rod extending in the left-right direction, and is movable at least in the front-rear direction, A press machine comprising: a work support that is provided in the shape of a plate extending in the front-rear direction so as to receive the rear portion of the workpiece placed on the lower die from below, the front portion of which is supported by a front support and the rear portion which rests on the girder.

2. It includes a rear support portion on which the rear portion of the workpiece holder can be placed, The aforementioned front support portion fixes the front portion of the workpiece holder. The front support portion and the rear support portion are each provided to be able to move up and down. The press machine according to claim 1, wherein the workpiece holder is lowered by the lowering of the front support portion and the rear support portion.

3. The press machine according to claim 2, wherein the rear support portion can be retracted away from the workpiece holder and below the movement path of the girder when the girder moves forward.

4. The press machine according to claim 2, wherein the front portion of the workpiece support is bendable when the front support portion descends by contacting a part of the main frame of the press machine.

5. The press machine according to claim 4, wherein the front support portion includes an elastic member that returns the front portion of the workpiece holder from a bent state to a straight state.

6. The press machine according to claim 2, wherein the girder is movable backward to a position where the workpiece holder is detached, and when the workpiece holder is detached, the front support and the rear support are lowered to lower the workpiece holder, thereby allowing the girder to move forward above the workpiece holder.

7. The press machine according to claim 2, wherein the movement of the girder is restricted when the rear support portion is raised.

8. The press machine according to claim 1, wherein multiple workpiece holders are arranged with spacing between them in the left-right direction.

9. The girder is equipped with a guide portion that extends in the left-right direction, The press machine according to claim 1, wherein the back gauge is movable in the left-right direction along the guide portion.

10. The press machine according to claim 1, wherein the girder is provided so as to be able to move up and down, and the height of the back gauge relative to the lower die can be changed.

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