Workpiece interference prevention system, workpiece interference prevention method, and bending machine

Abstract

According to the present invention, a control unit includes a back gauge control unit that controls the movement of a back gauge, and a robot control unit that controls the movement of a workpiece-holding robot. The back gauge control unit is configured to move the back gauge above or to the front of a lower mold before the workpiece is placed between an upper mold and the lower mold or removed therefrom. The back gauge control unit and the robot control unit operate the back gauge and the workpiece-holding robot to place the workpiece between the upper mold and the lower mold or remove the workpiece therefrom in a state in which a lower end part of the workpiece is supported from below by the back gauge.

Description

Workpiece interference prevention system, workpiece interference prevention method, and bending machine

[0001] The present invention relates to a workpiece interference prevention system, a workpiece interference prevention method, and a bending machine.

[0002] Conventionally, bending machines have been known that include upper and lower dies for bending plate-shaped workpieces, and a backgauge that is provided behind the upper and lower dies and positions the workpiece to be bent (for example, Patent Document 1 and Patent Document 2, etc.).

[0003] Patent No. 6243739 Patent No. 4404407

[0004] In conventional bending machines, including the bending machine described in Patent Document 1, in which a bending robot automatically transports a workpiece to a bending position, there is a risk that the workpiece being transported by the robot will bend downward due to its own weight, and therefore there is a risk that the workpiece will interfere with the lower die when traveling along a motion path that is preset for the robot.

[0005] Possible methods for avoiding the above-mentioned interference include setting a movement path for the robot in advance that takes into account the deflection of the workpiece, or performing a trial run of the robot and then teaching the robot a new movement path if there is a risk of interference.However, either method increases the workload and monitoring burden on workers such as robot operators, which may be a factor in reducing work efficiency during bending work.

[0006] Furthermore, even in conventional bending machines, including the bending machine described in Patent Document 2, in which the worker manually transports the workpiece to the bending position, there is a risk that the workpiece will bend due to its own weight, so the worker must check each time that there is no interference between the workpiece and the lower die when transporting it to the bending position, which may be a factor that reduces work efficiency during bending work.

[0007] One aspect of the present invention relates to a workpiece interference prevention system, a workpiece interference prevention method, and a bending machine that are capable of preventing interference between a workpiece and a lower die and improving work efficiency.

[0008] A workpiece interference prevention system according to one aspect of the present invention comprises a bending machine having an upper die, a lower die, and a backgage; a workpiece holding robot configured to be able to transport a workpiece between the upper die and the lower die; and a control unit that controls the bending machine and the workpiece holding robot, wherein the workpiece holding robot is arranged forward of the upper die and the lower die, and the backgage is arranged movably behind the upper die and the lower die, the control unit has a backgage control unit that controls the movement of the backgage and a robot control unit that controls the movement of the workpiece holding robot, the backgage control unit is configured to move the backgage above or in front of the lower die before the workpiece is loaded into or unloaded from between the upper die and the lower die, and the backgage control unit and the robot control unit operate the backgage and the workpiece holding robot to load or unload the workpiece between the upper die and the lower die while the lower end of the workpiece is supported from below by the backgage.

[0009] Furthermore, a method for preventing workpiece interference according to one embodiment of the present invention includes a moving step of moving the backgauge of the bending machine above or in front of the lower die before loading or unloading the workpiece between the upper and lower dies of the bending machine, a supporting step of supporting the lower end of the workpiece from below on the backgauge after the moving step, and a transporting step of loading or unloading the workpiece supported on the backgauge by the supporting step between the upper and lower dies of the bending machine.

[0010] Furthermore, a bending machine according to one embodiment of the present invention comprises an upper die and a lower die, a backgage movably arranged behind the lower die, and a control unit that controls the movement of the backgage, and the control unit is configured to move the backgage above or in front of the lower die before loading or unloading a workpiece between the upper die and the lower die, and with the lower end of the workpiece supported by the backgage, load or unload the workpiece between the upper die and the lower die.

[0011] A workpiece interference prevention system, workpiece interference prevention method, and bending machine according to one aspect of the present invention can prevent interference between the workpiece and the lower die by moving a backgauge above or in front of the lower die before loading or unloading the workpiece between the upper and lower dies, and loading or unloading the workpiece while the lower end of the workpiece is supported from below by the backgauge.

[0012] According to the workpiece interference prevention system, workpiece interference prevention method, and bending machine of one aspect of the present invention, it is possible to prevent interference between the workpiece and the lower die, thereby improving work efficiency.

[0013] FIG. 1 is a schematic diagram showing the overall configuration of a workpiece interference prevention system according to this embodiment. FIG. 2 is a schematic diagram showing the configuration of a backgage according to this embodiment. FIG. 3 is a block diagram showing a control unit according to this embodiment. FIG. 4 is an overall schematic diagram showing a state in which a support unit according to this embodiment has moved to an interference prevention position. FIG. 5A is a diagram showing the operation of a workpiece holding robot during temporary support control before a workpiece is carried in. FIG. 5B is a diagram showing the operation of a workpiece holding robot during full support control before a workpiece is carried in. FIG. 5C is a diagram showing the operation of a backgage and a workpiece holding robot when a workpiece is carried in. FIG. 6A is a diagram showing the operation of a backgage during temporary support control before a workpiece is carried out. FIG. 6B is a diagram showing the operation of a backgage during full support control before a workpiece is carried out. FIG. 6C is a diagram showing the operation of a backgage and a workpiece holding robot when a workpiece is carried out. FIG. 7 is a flowchart showing a workpiece interference prevention method before bending a workpiece according to this embodiment. FIG. 8 is a flowchart showing a workpiece interference prevention method after bending a workpiece according to this embodiment.

[0014] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. Furthermore, in the present embodiments, the scale and dimensions of each component may be exaggerated, and some components may be omitted.

[0015] [Configuration of Workpiece Interference Prevention System] Fig. 1 is a schematic diagram showing the overall configuration of a workpiece interference prevention system according to this embodiment. As shown in Fig. 1, the workpiece interference prevention system 1 according to this embodiment includes a bending machine 10 including an upper die (punch P), a lower die (die D), and a backgauge 13 movably provided behind the lower die (die D), a workpiece holding robot R configured to be able to transport a workpiece W from in front of the lower die (die D) to between the upper die (punch P) and the lower die (die D), and a control unit 20 that controls the bending machine 10 and the workpiece holding robot R.

[0016] In the work interference prevention system 1 according to this embodiment, the control unit 20 is configured to be able to send and receive information to and from a control unit (not shown) provided in the bending machine 10 and a control unit (not shown) provided in the work holding robot R, and performs a series of operations associated with bending the work W by outputting control signals to the control unit of the bending machine 10 and the control unit of the work holding robot R.

[0017] [Configuration of Bending Machine] The bending machine 10 is, for example, a press brake that bends a workpiece W and has an upper table 11 and a lower table 12. The upper table 11 is equipped with a punch P as an upper die, and the lower table 12 is equipped with a die D as a lower die. The upper table 11 is configured to be able to move toward and away from the lower table 12 by a drive mechanism (not shown) provided in the bending machine 10. The workpiece W to be bent is inserted between the punch P and the die D, and the upper table 11 is moved toward the lower table 12, thereby bending the workpiece W at a bending position (bending line F). Note that the bending machine 10 is not limited to a configuration in which the upper table 11 is able to move toward and away from the lower table 12; the lower table 12 may also be configured to be able to move toward and away from the upper table 11. In other words, in the bending machine 10, it is sufficient that the upper table 11 is configured to be able to move toward and away from the lower table 12 relatively.

[0018] In this specification, the "up-down direction" refers to the vertical direction (Z direction in FIG. 1) when the bending machine 10 is installed, and the "left-right direction" refers to the extension direction of the upper table 11 and the lower table 12 (X direction in FIG. 2) when the bending machine 10 is installed. In addition, the "front-rear direction" refers to the direction perpendicular to both the up-down direction and the left-right direction (Y direction in FIG. 1). In this specification, the side of the workpiece holding robot R (left side in FIG. 1) based on the bending position (bending line F) of the workpiece W in the bending machine 10 is described as the "front," and the opposite direction (right side in FIG. 1) is described as the "rear." However, the up-down direction, left-right direction, and front-rear direction in this specification are merely formal directions defined for convenience of explanation and do not necessarily correspond to the up-down direction, etc. in actual usage situations.

[0019] Fig. 2 is a schematic diagram showing the configuration of a backgage according to this embodiment. The bending machine 10 includes a backgage 13 that is movably provided behind a punch P (upper die) provided on an upper table and a die D (lower die) provided on a lower table 12. Specifically, as shown in Fig. 2, the backgage 13 has at least three support portions 14 that are movable along the front-to-rear direction (Y direction in Figs. 1 and 2), the left-to-right direction (X direction in Fig. 2), and the up-to-down direction (Z direction in Fig. 1) of the bending machine 10.

[0020] Of the three support portions 14, the first support portion 14A and the third support portion 14C function as support members that support the lower end portion of the workpiece W from below, and also function as abutting members that allow the front end portion of the workpiece W to abut against a first upper-stage abutting portion 17A and a third upper-stage abutting portion 17C, which will be described later. The second support portion 14B functions as a support member that supports the side end portion of the workpiece W from below, and also functions as abutting member that allows the side end portion of the workpiece W to abut against a second upper-stage abutting portion 17B, which will be described later.

[0021] In this specification, the "lower end" of the workpiece W refers to the part (end) located at the lowest position (downward in FIG. 1) of the workpiece W, and is defined as follows: (1) In the workpiece W before bending, the lower edge of the front end of the workpiece W. (2) In the workpiece W after bending, the lower edge of the bent portion of the workpiece W.

[0022] Furthermore, in this specification, the "front end" and "side end" of the workpiece W are not limited to the front edge and side edge of the workpiece W, but also include the inner edge of the workpiece W formed by a notch or hole formed in the workpiece W and the intersection between the front edge and side edge of the workpiece W.

[0023] The backgauge 13 is configured so that a control unit (not shown) included in the bending machine 10 receives control signals output from a backgauge control unit 23 of the control unit 20, which will be described later, to move the first support unit 14A, the second support unit 14B, and the third support unit 14C in the up-down direction (Z direction in FIG. 1), the left-right direction (X direction in FIG. 2), and the front-rear direction (Y direction in FIGS. 1 and 2). Note that, since known configurations and structures can be adopted for the basic configurations and structures of the backgauge 13 and the support units 14, a description of the specific configurations and structures will be omitted in this specification.

[0024] The backgauge 13 also includes a mounting portion 16 on which the lower end of the workpiece W can be placed. Furthermore, the support portion 14 further includes an upper abutment portion 17 provided behind the mounting portion 16. Specifically, as shown in FIG. 2 , the support portion 14 of the backgauge 13 includes a lower abutment portion 15, a mounting portion 16 provided behind the lower abutment portion 15, and an upper abutment portion 17 provided behind the mounting portion 16. Note that in the bending machine 10 according to this embodiment, each support portion 14 of the backgauge 13 includes the lower abutment portion 15, the mounting portion 16, and the upper abutment portion 17.

[0025] When the front end of the workpiece W does not abut against the upper abutment portion 17 described later, the lower abutment portion 15 functions as an abutment member that can abut against the front end of the workpiece W transported between the punch P and the die D. Note that a known configuration can be adopted for the lower abutment portion 15, and therefore detailed description thereof will be omitted.

[0026] The loading section 16 is configured so that the lower end of the workpiece W can be placed on it, and is configured so that the workpiece W can be transported between the punch P (upper die) and the die D (lower die) or removed from between the punch P and the die D with the lower end of the workpiece W placed on it.

[0027] A mounting portion 16 is provided on each of the first support portion 14A to the third support portion 14C. Specifically, the first support portion 14A has a first mounting portion 16A provided behind the first lower-stage abutment portion 15A, the second support portion 14B has a second mounting portion 16B provided behind the second lower-stage abutment portion 15B, and the third support portion 14C has a third mounting portion 16C provided behind the third lower-stage abutment portion 15C. Each of the mounting portions 16A to 16C is formed in a rectangular shape with a smooth surface on which the workpiece W can be placed.

[0028] Furthermore, the placement portion 16 is configured to be longer in the left-right direction (X direction) than the lower abutment portion 15. This configuration makes it easier to place the lower end of the workpiece W on the placement portion 16, and also improves stability when transporting the workpiece W relative to the punch P and die D.

[0029] The mounting portion 16 is preferably made of a material having a certain degree of elasticity in order to prevent breakage of the workpiece W when the lower end of the workpiece W is mounted on the mounting portion 16. For example, nylon or the like can be used as such a material, but is not limited to this.

[0030] In the above description, the mounting portion 16 is described as being formed in a rectangular shape with a smooth surface on which the lower end of the workpiece W can be placed, but this is not limited thereto. For example, the mounting portion 16 may be formed in a rectangular shape with an inclined surface sloping from front to rear, or the mounting portion 16 may be formed in an arc shape with a curved surface. Various shapes can be adopted for the mounting portion 16 as long as at least the lower end of the workpiece W can be placed thereon. In addition, in the above description, each mounting portion 16 is described as being formed in a rectangular shape with a smooth surface on which the lower end of the workpiece W can be placed. However, this is not limited thereto. For example, the first mounting portion 16A and the second mounting portion 16B may be formed in a rectangular shape with an inclined surface sloping from front to rear, and the third mounting portion 16C may be formed in an arc shape with a curved surface. Each mounting portion 16 may be formed in a different shape.

[0031] The upper abutment section 17 is provided behind the loading section 16 and is configured to transport the workpiece W between the punch P (upper die) and the die D (lower die) or transport the workpiece W from between the punch P and the die D while the workpiece W is abutted against the upper abutment section 17.

[0032] The upper-stage abutment portion 17 is provided on each of the first support portion 14A to the third support portion 14C. Specifically, the first support portion 14A has a first upper-stage abutment portion 17A provided behind the first mounting portion 16A, the second support portion 14B has a second upper-stage abutment portion 17B provided behind the second mounting portion 16B, and the third support portion 14C has a third upper-stage abutment portion 17C provided behind the third mounting portion 16C.

[0033] Here, the first upper abutting portion 17A and the third upper abutting portion 17C are configured so that the front end of the workpiece W to be bent abuts against them when the workpiece W is carried between the punch P and the die D, and so that the bottom end of the workpiece W abuts against them when the bent workpiece W is carried out from between the punch P and the die D. The second upper abutting portion 17B is configured so that the side end of the workpiece W abuts against them when the workpiece W is carried into or carried out from between the punch P and the die D.

[0034] In addition, the upper abutment portion 17 is formed so that its length (height) in the vertical direction (Z direction) is longer than the length (height) in the vertical direction of the loading portion 16, and is configured to be able to stably abut against the front end or bottom end of the workpiece W when it is placed on the loading portion 16.

[0035] Furthermore, the upper abutment portion 17 is provided so that its front end abuts against the rear end of the mounting portion 16. That is, in this embodiment, the upper abutment portion 17 is provided contiguous with the mounting portion 16 at the top of the support portion 14. However, this is not limiting, and the upper abutment portion 17 and the mounting portion 16 may be provided with a gap therebetween.

[0036] Moreover, the upper abutting portion 17 is configured to be able to be housed inside the support portion 14. Specifically, the upper abutting portion 17 is configured to be able to move left and right (in the Y direction) by a drive mechanism (not shown) provided in the support portion 14, and is configured to be able to switch between a state in which the upper abutting portion 17 is exposed to the outside of the support portion 14 and a state in which the upper abutting portion 17 is housed inside the support portion 14. By configuring the upper abutting portion 17 in this way, the upper abutting portion 17 can be housed inside the support portion 14 during excess movement control by the backgage control portion 23 and the robot control portion 24, which will be described later, and therefore it is possible to prevent interference between the upper abutting portion 17 and the lower end of the workpiece W.

[0037] [Configuration of Workpiece Holding Robot] The workpiece holding robot R is provided forward of the punch P (upper die) and the die D (lower die). Specifically, the workpiece holding robot R is disposed between the bending machine 10 and a loading area (not shown) where multiple workpieces W can be placed, and is configured to hold a workpiece W to be bent among the multiple workpieces W loaded in the loading area and transport the workpiece W between the punch P and the die D.

[0038] The workpiece holding robot R also includes a control unit (not shown), and is configured to receive control signals output from a robot control unit 24 of the control unit 20 (described later) to cooperate with the backgauge 13 of the bending machine 10 and automatically execute a series of operations related to the bending work. Note that a known configuration can be adopted for the configuration of such a workpiece holding robot R, and therefore a detailed description thereof will be omitted.

[0039] [Configuration of Control Unit] Fig. 3 is a block diagram showing a schematic configuration of the control unit according to this embodiment. The control unit 20 is configured with a general-purpose NC (Numerical Control) device or a personal computer, and is configured to be able to communicate data with the bending machine 10 and the workpiece holding robot R. As shown in Fig. 3, the control unit 20 includes a backgage position determination unit 21, a robot position determination unit 22, a backgage control unit 23, and a robot control unit 24. Note that a known configuration can be adopted for the basic configuration of the control unit 20, and therefore detailed description thereof will be omitted.

[0040] The backgage position determination unit 21 determines the operating position of the backgage 13 before the workpiece W is carried into and removed from between the punch P and the die D, based on information relating to the dimensions and arrangement positions of the punch P and the die D, and information relating to the dimensions of the workpiece W, and stores information relating to the operating position of the backgage 13 in a memory unit (not shown) provided in the control unit 20. In addition, the backgage position determination unit 21 determines the operating path of the backgage 13 when the workpiece W is carried into and removed from between the punch P and the die D, and stores information relating to the operating path of the backgage 13 in the memory unit of the control unit 20.

[0041] The robot position determination unit 22 determines the operating path of the workpiece holding robot R when loading the workpiece W between the punch P and the die D and unloading the workpiece W from between the punch P and the die D based on information regarding the dimensions of the workpiece W to be transported by the workpiece holding robot R, the dimensions of the backgauge 13, and the interference prevention position of the backgauge 13 described below, and stores information regarding the operating path of the workpiece holding robot R in a memory unit (not shown) of the control unit 20.

[0042] The backgage control unit 23 reads information regarding the operating position and operating path of the backgage 13, which is determined by the backgage position determination unit 21 and stored in the memory unit (not shown) of the control unit 20, from the memory unit, and transmits this information to the control unit (not shown) of the bending machine 10, thereby controlling the operation of the backgage 13.

[0043] Fig. 4 is an overall schematic diagram showing a state in which the backgage according to this embodiment has been moved to the interference prevention position. As shown in Fig. 4, the backgage control unit 23 is configured to move the backgage 13 above the punch P (upper die) and the die D (lower die) or in front of the die D before the workpiece W is carried into or out of the space between the die D. The backgage control unit 23 also moves the first support portion 14A so as to support the front end portion of the workpiece W from below, and moves the second support portion 14B so as to support the side end portion of the workpiece W from below.

[0044] Specifically, before the workpiece W is loaded or unloaded between the punch P and the die D, the backgage control unit 23 moves the first support portion 14A of the backgage 13 in the vertical direction (Z direction) and the front-to-back direction (Y direction) so that it is positioned above or in front of the die D, moves the second support portion 14B in the vertical direction (Z direction) and the front-to-back direction (Y direction) so that it is positioned to the side or in front of the die D, and moves the third support portion 14C in the vertical direction (Z direction) and the front-to-back direction (Y direction) so that it is positioned above or in front of the die D.

[0045] In this specification, "above or in front of the lower mold (die D)" is explained as referring to the upward direction (above in Figure 1) or the forward direction (left side in Figure 1) based on the upper end on the front side (left side in Figure 1) of the lower mold (die D), and "side of the lower mold (die D)" is explained as referring to the end on one side (the right side in Figure 4) of the lower mold (die D) in the left-right direction (X direction).

[0046] Furthermore, "moving the backgauge 13 above the lower mold (die D) or in front of the lower mold (die D)" means moving the backgauge 13 so that at least the backgauge 13 is positioned above or in front of the lower mold (die D), and specifically means moving the support portion 14 of the backgauge 13 so that the lower abutment portion 15 provided on the support portion 14 is positioned above or in front of the die D.

[0047] However, from the viewpoint of improving the support capacity for the workpiece W and reliably preventing interference between the workpiece W and the die D, it is preferable to move the support parts 14 so that the placement parts 16 provided on the support parts 14 of the backgage 13 are positioned above or in front of the die D before the workpiece W is carried into or out of the space between the upper die (punch P) and the lower die (die D). Also, from the viewpoint of further improving the support capacity for the workpiece W and quickly performing bending processing on the workpiece W by abutting the front end of the workpiece W carried into or out of the space between the punch P and the die D, it is more preferable to move the support parts 14 so that the upper abutment parts 17 provided on the support parts 14 of the backgage 13 are positioned above or in front of the die D before the workpiece W is carried into or out of the space between the upper die (punch P) and the lower die (die D).

[0048] The robot control unit 24 reads information about the notified movement path of the workpiece holding robot R, which has been determined by the robot position determination unit 22 and stored in a memory unit (not shown) of the control unit 20, from the memory unit, and transmits the information about the movement path to the control unit (not shown) of the workpiece holding robot R, thereby performing movement control of the workpiece holding robot R.

[0049] Furthermore, the backgage control unit 23 and the robot control unit 24 are configured to operate the backgage 13 and the workpiece holding robot R to carry the workpiece W into or out of the space between the punch P (upper die) and the die D (lower die) while the lower end of the workpiece W is supported from below by the backgage 13. The operation of the backgage 13 and the workpiece holding robot R by the backgage control unit 23 and the robot control unit 24 will be described in detail later.

[0050] Here, in this specification, "supporting the lower end of the workpiece from below with the backgage" will be described as including not only a configuration in which the robot control unit 24 moves the workpiece holding robot R downward, thereby supporting the lower end of the workpiece W from below with the backgage 13, but also a configuration in which the backgage control unit 23 described above moves the backgage 13 upward toward the lower end of the workpiece W, thereby supporting the lower end of the workpiece W from below with the backgage 13. In other words, in the workpiece interference prevention system 1 according to this embodiment, when the lower end of the workpiece W is supported from below with the backgage 13, it is sufficient that the backgage 13 is configured to move relative to the lower end of the workpiece W.

[0051] Furthermore, the control unit 20 according to this embodiment is configured to be able to execute excess travel control, which operates at least one of the backgage 13 and the workpiece holding robot R so that the placement portion 16 of the backgage 13 is positioned forward of the lower end of the workpiece W, temporary support control, which operates the backgage 13 and the workpiece holding robot R in the vertical direction after the excess travel control so that the lower end of the workpiece W is supported at a position rearward of the placement portion 16 of the backgage 13, and final support control, which operates at least one of the backgage 13 and the workpiece holding robot R in the forward and backward direction after the temporary support control so that the lower end of the workpiece W is placed on the placement portion 16. Specific controls performed by the control unit 20 will be described in detail later.

[0052] [Interference prevention control during bending processing] In this embodiment, the control unit 20 is configured to reliably support the lower end of the workpiece W from below using the backgauge 13 before bending processing, and to be able to execute a series of operational controls to transport the workpiece W between the punch P and the die D while the lower end of the workpiece W is supported from below by the backgauge 13.

[0053] In the following explanation, the series of controls during bending processing will be described as being performed by the workpiece holding robot R operating under the operation control of the robot control unit 24 of the control unit 20, but this is not limited to this, and the series of controls may also be performed by the backgage 13 operating under the operation control of the backgage control unit 23 of the control unit 20, or by the operation of both the backgage 13 and the workpiece holding robot R under the operation control of the backgage control unit 23 and the robot control unit 24.

[0054] Here, the robot control unit 24 of the control unit 20 is configured to be able to perform excess movement control, which operates the work holding robot R so that the loading portion 16 of the backgage 13 is positioned forward of the lower end of the work W; temporary support control, which operates the work holding robot R in the vertical direction so that the lower end of the work W is supported at a position rearward of the loading portion 16 of the backgage 13 after the excess movement control; and main support control, which operates the work holding robot R in the forward and backward directions so that the lower end of the work W is placed on the loading portion 16 after the temporary support control.

[0055] Specifically, in the excess travel control in the robot control unit 24, when the workpiece W before bending is supported on the support portion 14 of the backgage 13 that has been moved to the interference prevention position, the workpiece holding robot R is moved backward so that the ideal placement location PL on the placement portion 16 provided on the support portion 14 of the backgage 13 is positioned forward of the workpiece W. In the following explanation, the "ideal placement location" will be explained as referring to the position of the rear end of the placement portion 16.

[0056] FIG. 5A is a diagram schematically illustrating the operation of the workpiece holding robot during temporary support control before the workpiece is loaded. FIG. 5B is a diagram schematically illustrating the operation of the workpiece holding robot during full support control before the workpiece is loaded. Then, in the temporary support control by the robot control unit 24, as shown in FIG. 5A , the workpiece holding robot R is moved downward so that the lower end of the workpiece W is supported on a portion of the backgage 13 rearward of the placement portion 16 (the upper abutment portion 17 in FIG. 5A ). At this time, the robot control unit 24 preferably moves the workpiece holding robot R downward to a position where the front end of the workpiece W is perpendicular to the upper end of the placement portion 16 of the support unit 14. Then, in the full support control by the robot control unit 24, as shown in FIG. 5B , the workpiece holding robot R is moved forward (to the right in FIG. 5B ) so that the front end of the workpiece W coincides with the ideal placement location PL, and the lower end of the workpiece W is placed on the placement portion 16.

[0057] By executing such operation control, the robot control unit 24 can reliably place the lower end of the workpiece W on the placement unit 16 even if the workpiece W before bending is bent downward. In other words, if the workpiece W before bending is significantly bent, it is difficult to place the lower end of the workpiece W directly on the placement unit 16. However, by first supporting the lower end of the workpiece W at a position on the support unit 14 that is rearward of the placement unit 16 and then moving the workpiece holding robot R downward, the bending of the workpiece W can be reduced, and then the workpiece holding robot R can be moved in the front-to-rear direction until the front end of the workpiece W coincides with the ideal placement position PL, so that the lower end of the workpiece W can be accurately placed within the range of the placement unit 16.

[0058] Furthermore, in addition to the above-described operation control, the robot control unit 24 according to this embodiment is configured to be able to execute abutting control in which the workpiece W before bending is butted against the upper butting portion 17 provided on the support portion 14 of the backgage 13. Specifically, the butting control in the robot control unit 24 is configured to, after the above-described placement control, move the workpiece holding robot R backward (to the left in FIG. 5B ) until the front end of the workpiece W before bending butts against the upper butting portion 17. In this way, by configuring the robot control unit 24 to be able to execute abutting control, the support capacity of the workpiece W before bending is further improved, and it is possible to butt the workpiece W ahead of the bending position (bending line F) of the bending machine 10. This eliminates the need to perform a new butting operation within the bending machine 10, thereby improving work efficiency.

[0059] After the robot control unit 24 executes the operation control of the workpiece holding robot R described above, the backgage control unit 23 and the robot control unit 24 are configured to operate the backgage 13 and the workpiece holding robot R so as to carry the workpiece W between the punch P (upper die) and the die D (lower die). Specifically, the backgage control unit 23 and the robot control unit 24 are configured to operate the backgage 13 and the workpiece holding robot R so as to carry the workpiece W between the punch P and the die D in a state in which the workpiece W is abutted against the upper abutment unit 17 and the lower end of the workpiece W is placed on the placement unit 16.

[0060] 5C is a diagram schematically illustrating the operation of the backgage and the workpiece holding robot when a workpiece is carried in. In this embodiment, when the backgage control unit 23 and the robot control unit 24 determine, through the operation control of the robot control unit 24 described above, that the pre-bent workpiece W abuts against the upper abutting portion 17 of the support portion 14 and that the lower end of the pre-bent workpiece W is placed on the placement portion 16, they move the support portion 14 of the backgage 13 backward (to the left in FIG. 5C ) as shown in FIG. 5C , and move the workpiece holding robot R backward (to the left in FIG. 5C ) so as to follow the movement of the support portion 14. As a result, the pre-bent workpiece W is carried between the punch P and the die D as shown in FIG. 5C .

[0061] In the work interference prevention system 1 according to this embodiment, the control unit 20 compares and calculates the operating position and operating path of the backgage 13 determined and stored in the backgage position determination unit 21 and the robot position determination unit 22 with the operating path of the work holding robot R in advance, thereby determining that the work W before bending is abutted against the upper abutment portion 17 provided on the support unit 14, and that the lower end of the work W before bending is placed on the placement portion 16.

[0062] However, the manner in which it is determined that the pre-bending workpiece W is abutted against the upper abutment portion 17 of the support portion 14 and that the lower end of the pre-bending workpiece W is placed on the placement portion 16 is not limited to the above. For example, various other manners can be adopted, such as a configuration in which a pressure sensor or the like is provided on the placement portion 16, and when the pressure sensor detects that the workpiece W has been placed on the placement portion 16, the backgage control portion 23 and the robot control portion 24 operate the backgage 13 and the workpiece holding robot R to transport the pre-bending workpiece W between the punch P and the die D.

[0063] [Interference prevention control after bending] In this embodiment, the control unit 20 is configured to ensure that the lower end of the workpiece W after bending is reliably supported from below by the backgauge 13, and to be able to execute a series of operational controls to transport the workpiece W from between the punch P and the die D while the lower end of the workpiece W is supported from below by the backgauge 13.

[0064] In the following explanation, the series of controls after bending will be described as being performed by operating the backgage 13 under the operation control of the backgage control unit 23 of the control unit 20, but this is not limited to this, and the series of controls may also be performed by operating the workpiece holding robot R under the operation control of the robot control unit 24 of the control unit 20, or by operating both the backgage 13 and the workpiece holding robot R under the operation control of the backgage control unit 23 and the robot control unit 24. However, from the viewpoint of preventing interference between the workpiece holding robot R and the upper table 11 of the bending machine 10, it is desirable that the series of controls after bending be performed by operating the backgage 13 under the operation control of the backgage control unit 23.

[0065] Here, the backgauge control unit 23 of the control unit 20 is configured to be able to perform excess movement control, which operates the backgauge 13 so that the loading portion 16 of the backgauge 13 is positioned forward of the lower end of the workpiece W after bending processing; temporary support control, which operates the backgauge 13 in the vertical direction so that the lower end of the workpiece W is supported at a position rearward of the loading portion 16 of the backgauge 13 after the excess movement control; and main support control, which operates the backgauge 13 in the forward and backward directions so that the lower end of the workpiece W is placed on the loading portion 16 after the temporary support control.

[0066] Specifically, in the excess movement control in the backgage control unit 23, when the workpiece W after bending is supported on the support portion 14 of the backgage 13 that has been moved to an interference prevention position, the support portion 14 is moved forward so that the ideal loading point PL on the loading portion 16 provided on the support portion 14 of the backgage 13 is positioned forward of the workpiece W.

[0067] 6A is a diagram schematically illustrating the operation of the backgage during temporary support control before the workpiece is carried out. Also, FIG. 6B is a diagram schematically illustrating the operation of the backgage during main support control before the workpiece is carried out. Then, during temporary support control in the backgage control unit 23, the support unit 14 is moved upward so that the lower end of the workpiece W is supported on a portion of the backgage 13 rearward of the placement unit 16 (in FIG. 6A , the upper end of the support unit 14). Then, during main support control in the backgage control unit 23, the support unit 14 is moved rearward (to the left in FIG. 6B ) so that the lower end of the workpiece W is positioned slightly forward of the ideal placement position PL, as shown in FIG. 6B , and the lower end of the workpiece W after bending is placed on the placement unit 16.

[0068] By executing such operation control, the backgage control unit 23 can reliably place the lower end of the workpiece W on the placement unit 16 even if the workpiece W is bent downward after bending. In other words, if the workpiece W is significantly bent after bending, it is difficult to place the lower end of the workpiece W directly on the placement unit 16. However, after the lower end of the workpiece W is supported by the support unit 14, the support unit 14 is moved in the forward / backward direction so that the lower end of the workpiece W is positioned slightly forward of the ideal placement position PL, so that the lower end of the workpiece W can be accurately placed within the range of the placement unit 16.

[0069] Furthermore, the backgage control unit 23 according to this embodiment is configured to be able to execute, in addition to the above-described operation control, butt control in which the bent workpiece W butts against the upper butt portion 17 provided on the support portion 14 of the backgage 13. Specifically, after the above-described placement control, the backgage control unit 23 is configured to move the support portion 14 of the backgage 13 forward (to the right in FIG. 6B ) to a position where the lower end of the bent workpiece W butts against the upper butt portion 17. In this way, the backgage control unit 23 is configured to be able to execute butt control, which makes it possible to further improve the support capacity for the bent workpiece W.

[0070] After the backgage control unit 23 executes the operation control of the backgage 13 as described above, the backgage control unit 23 and the robot control unit 24 are configured to operate the backgage 13 and the workpiece holding robot R to carry out the workpiece W from between the punch P (upper die) and the die D (lower die). Specifically, the backgage control unit 23 and the robot control unit 24 are configured to operate the backgage 13 and the workpiece holding robot R to carry out the workpiece W from between the punch P and the die D in a state in which the workpiece W is abutted against the upper abutment unit 17 and the lower end of the workpiece W is placed on the placement unit 16.

[0071] 6C is a diagram schematically illustrating the operation of the backgage and the workpiece holding robot when the workpiece is carried out. In this embodiment, when the backgage control unit 23 and the robot control unit 24 determine, through the operation control of the backgage control unit 23 described above, that the bent workpiece W abuts against the upper abutment portion 17 of the support portion 14 and that the lower end of the bent workpiece W is placed on the placement portion 16, they move the support portion 14 of the backgage 13 forward (to the right in FIG. 6C ) as shown in FIG. 6C , and move the workpiece holding robot R forward (to the right in FIG. 6C ) so as to follow the movement of the support portion 14. As a result, the bent workpiece W is carried out from between the punch P and the die D as shown in FIG. 6C .

[0072] The manner in which the workpiece W before bending is abutted against the upper abutment portion 17 provided on the support portion 14 and the lower end portion of the workpiece W before bending is placed on the placement portion 16 is the same as the content of the interference prevention control during bending described above, so a description thereof will be omitted.

[0073] [Workpiece Interference Prevention Method] Figure 7 is a flowchart showing a workpiece interference prevention method according to this embodiment, performed before bending the workpiece. Also, Figure 8 is a flowchart showing an interference prevention method according to this embodiment, performed after bending the workpiece. Next, a workpiece interference prevention method using the workpiece interference prevention system 1 according to this embodiment will be described with reference to Figures 7 and 8. The workpiece interference prevention method according to this embodiment includes a moving step of moving the backgauge 13 of the bending machine 10 above or in front of the lower die (die D) before loading or unloading the workpiece W between the punch P (upper die) and the die D (lower die) of the bending machine 10, a supporting step of supporting the lower end of the workpiece W from below on the backgauge 13 after the moving step, and a transporting step of loading or unloading the workpiece W supported by the supporting step between the punch P and the die D of the bending machine 10.

[0074] FIG. 7 shows the flow of the interference prevention process when a workpiece W to be bent is loaded between the punch P and the die D and bent. FIG. 8 shows the flow of the interference prevention process when the bent workpiece W is unloaded from between the punch P and the die D. In this embodiment, the interference prevention process in FIG. 7 and the interference prevention process in FIG. 8 are performed consecutively. In the following description, the workpiece W is transported automatically using a workpiece holding robot R, but this is not limited thereto, and the workpiece W may be transported manually by an operator engaged in the bending operation of the workpiece W. In addition, the workpiece W transported by the workpiece holding robot R is described as not having a flange, but this is not limited thereto, and the workpiece W transported by the workpiece holding robot R may have a flange.

[0075] As shown in FIG. 7 , first, when the bending work (S1) is started by the worker engaged in the bending work, the robot control unit 24 of the control unit 20 reads information regarding the operating path of the workpiece holding robot R determined by the robot position determination unit 22 and stored in a memory unit (not shown) of the control unit 20, and starts operating the workpiece holding robot R.

[0076] After the workpiece holding robot R starts operating, the backgage control unit 23 of the control unit 20 reads information about the operating position of the backgage 13 during interference prevention, which information was determined by the backgage position determination unit 21 and stored in a memory unit (not shown) of the control unit 20, and moves the backgage 13 (S2). Specifically, the backgage control unit 23 moves the first support portion 14A and the third support portion 14C of the backgage 13 so that they are positioned above or in front of the die D, respectively, and moves the second support portion 14B so that they are positioned to the side or in front of the die D. For convenience of explanation, the operation control of the backgage 13 by the backgage control unit 23 (S2) will be described as being performed after the workpiece holding robot R starts operating; however, the backgage control unit 23 may move the backgage 13 to a predetermined position in advance before the workpiece holding robot R starts operating.

[0077] After the backgage 13 has moved to a predetermined position, the robot control unit 24 executes an excess movement step (S3) of operating the workpiece holding robot R so that the placement portion 16 of the backgage 13 is positioned forward of the lower end of the workpiece W held by the workpiece holding robot R. Note that the control content by the robot control unit 24 during bending is as described above, and therefore a detailed description thereof will be omitted.

[0078] After the excess movement step (S3) is performed, the robot control unit 24 performs a temporary support step (S4) in which the workpiece holding robot R is moved up and down so that the lower end of the workpiece W is supported at a location rearward of the placement portion 16 of the backgage 13, and then performs a main support step (S5) in which the workpiece holding robot R is moved back and forth so that the lower end of the workpiece W is placed on the placement portion 16. Furthermore, after the main support step (S5) is performed, the robot control unit 24 performs an abutment step (S6) in which the workpiece holding robot R is moved so that the workpiece W abuts against the upper abutment portion 17 of the backgage 13.

[0079] Thereafter, with the workpiece W abutted against the upper abutment portion 17 and the lower end of the workpiece W placed on the placement portion 16, the backgage control portion 23 and the robot control portion 24 operate the support portion 14 of the backgage 13 and the workpiece holding robot R to load the workpiece W between the punch P and the die D (S7) and perform bending work on the workpiece W (S8). At this point, the work of preventing interference between the workpiece W and the die D from loading the workpiece W to bending work is completed.

[0080] After the workpiece W has been bent (after S8), as shown in Fig. 8, the robot control unit 24 moves the workpiece holding robot R upward to a position where interference between the support portions 14 and the workpiece holding robot R will not occur when the support portions 14 of the backgage 13 move to their post-bending interference prevention positions (S9). The upper table 11 of the bending machine 10 is configured to move upward (to the home position) after bending the workpiece W, but when the upper table moves upward, there is a risk of interference between the bent workpiece W and the punch P. From the perspective of avoiding such interference, it is preferable that the robot control unit 24 be configured to move the workpiece holding robot R so that the workpiece holding robot R can follow the movement of the upper table 11 of the bending machine 10.

[0081] After the workpiece holding robot R has moved (S9), the backgage control unit 23 reads information about the operating position of the backgage 13 after bending, which information was determined by the backgage position determination unit 21 and stored in a memory unit (not shown) of the control unit 20, and moves the support unit 14 of the backgage 13 (S10). Note that the operating position of the support unit 14 in S10 may be the same as or different from the operating position of the backgage 13 in S2 described above.

[0082] After the backgage 13 has been moved to a predetermined position in S10, the backgage control unit 23 executes an excess movement step (S11) of operating the support portion 14 of the backgage 13 so that the mounting portion 16 of the backgage 13 is positioned forward of the lower end portion of the workpiece W after bending. Note that the control content by the backgage control unit 23 after bending is as described above, and therefore a detailed description thereof will be omitted.

[0083] After the excess movement step (S11) is performed, the backgage control unit 23 performs a temporary support step (S12) of moving the backgage 13 in the vertical direction so that the lower end of the workpiece W is supported at a location on the backgage 13 rearward of the mounting portion 16, and then performs a main support step (S13) of moving the backgage 13 in the front-rear direction so that the lower end of the workpiece W is placed on the mounting portion 16. Furthermore, after the main support step (S13) is performed, the backgage control unit 23 performs an abutment step (S14) of moving the backgage 13 so that the lower end of the workpiece W after bending abuts against the upper abutment portion 17 of the backgage 13.

[0084] Thereafter, with the bent workpiece W abutted against the upper abutting portion 17 and the lower end of the bent workpiece W placed on the placing portion 16, the backgage control portion 23 and the robot control portion 24 operate the support portion 14 of the backgage 13 and the workpiece holding robot R to carry the workpiece W out from between the punch P and the die D (S15). This completes the work of preventing interference between the workpiece W and the die D from bending to carrying out the workpiece W. Thereafter, the bending work of the workpiece W is continuously carried out by repeatedly executing the steps from S2 to S15 described above.

[0085] [Advantages of the workpiece interference prevention system, workpiece interference prevention method, and bending machine according to this embodiment] As described above, the workpiece interference prevention system 1 according to this embodiment includes a bending machine 10 having a punch P (upper die), a die D (lower die), and a backgage 13, a workpiece holding robot R configured to be able to transport the workpiece W between the punch P (upper die) and the die D (lower die), and a control unit 20 that controls the bending machine 10 and the workpiece holding robot R, the workpiece holding robot R is provided forward of the punch P (upper die) and the die D (lower die), the backgage 13 is provided movably behind the punch P (upper die) and the die D (lower die), and the control unit 20 functions as a backgage control unit 23 that controls the movement of the backgage 13. and a robot control unit 24 that controls the movement of the workpiece holding robot R, and the backgage control unit 23 is configured to move the backgage 13 above or in front of the die D (lower die) before the workpiece W is carried into or out of the space between the punch P (upper die) and the die D (lower die), and the backgage control unit 23 and the robot control unit 24 are configured to operate the backgage 13 and the workpiece holding robot R to carry the workpiece W into or out of the space between the punch P (upper die) and the die D (lower die) while the lower end of the workpiece W is supported from below by the backgage 13.

[0086] Furthermore, by being configured in this manner, the workpiece interference prevention system 1 according to this embodiment can effectively prevent interference between the workpiece W and the die D. Furthermore, since it is not necessary for the operator to re-teach the operation path of the workpiece holding robot R, it is possible to reduce the workload on the operator during bending, by having the backgage 13 move above or forward of the die D to support the lower end of the workpiece W from below.

[0087] Furthermore, in the workpiece interference prevention system 1 according to this embodiment, the backgage 13 includes a mounting portion 16 on which the lower end of the workpiece W can be placed, and the backgage control portion 23 and the robot control portion 24 are configured to operate the backgage 13 and the workpiece holding robot R so as to carry the workpiece W between the punch P (upper die) and the die D (lower die) or remove it from between the punch P (upper die) and the die D (lower die) with the lower end of the workpiece W placed on the mounting portion 16. With this configuration, the workpiece W can be stably supported by the backgage 13, and therefore interference between the workpiece W and the die D can be more reliably prevented when the workpiece W is carried in or out between the punch P and the die D.

[0088] Furthermore, in the workpiece interference prevention system 1 according to this embodiment, the control unit 20 is configured to execute the following: excess travel control, which operates at least one of the backgage 13 and the workpiece holding robot R so that the placement portion 16 of the backgage 13 is positioned forward of the lower end of the workpiece W; temporary support control, which operates at least one of the backgage 13 and the workpiece holding robot R in the vertical direction so that the lower end of the workpiece W is supported at a location rearward of the placement portion 16 of the backgage 13 after the excess travel control; and final support control, which operates at least one of the backgage 13 and the workpiece holding robot R in the forward and backward direction so that the lower end of the workpiece W is placed on the placement portion 16 after the temporary support control. This configuration allows the lower end of the workpiece W to be stably placed on the placement portion 16 even when the workpiece W to be transported has a large amount of deflection, thereby further improving the support capacity of the backgage 13 for the workpiece W. It is also possible to prevent interference between the workpiece W and the backgage 13 due to incorrect placement of the workpiece W on the placement portion 16 during transport.

[0089] Furthermore, in the workpiece interference prevention system 1 according to this embodiment, the backgage 13 further includes an upper abutment portion 17 provided behind the mounting portion 16, and the backgage control portion 23 and the robot control portion 24 are configured to operate the backgage 13 and the workpiece holding robot R so as to carry the workpiece W between the punch P (upper die) and the die D (lower die) or carry it out from between the punch P (upper die) and the die D (lower die) when the workpiece W is abutted against the upper abutment portion 17 and the lower end of the workpiece W is placed on the mounting portion 16. This configuration further improves the support capacity of the backgage 13 for the workpiece W. Furthermore, by abutting the front surface of the workpiece W forward of the bending position (bending line F) of the bending machine 10 when carrying the workpiece W, it is possible to omit the abutting process of the workpiece W after carrying it between the punch P and the die D, thereby further improving work efficiency during bending operations.

[0090] Furthermore, in the workpiece interference prevention system 1 according to this embodiment, the backgage 13 includes a first support portion 14A that supports the front end of the workpiece W and a second support portion 14B that supports the side end of the workpiece W. With this configuration, the workpiece W to be transported can be supported not only from the front side but also from the side, further improving the support capacity for the workpiece W. Furthermore, when the workpiece W to be transported has flanges on its side end, the second support portion 14B allows the workpiece W to be accurately positioned in the left-right direction (X direction).

[0091] [Modifications] While the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the scope described in the above-described embodiments. Various modifications and improvements can be made to the above-described embodiments.

[0092] For example, in the above-described embodiment, the backgage 13 has been described as having the placement portion 16 on which the lower end of the workpiece W can be placed, but this is not limited thereto, and the backgage 13 may not have the placement portion 16. Accordingly, the excess movement control, support control, and placement control by the backgage control unit 23 and the robot control unit 24 may not be executed.

[0093] In the above embodiment, the backgage 13 is described as further including the upper abutment portion 17 provided behind the placement portion 16, but this is not limitative and the backgage 13 may not include the upper abutment portion 17. Accordingly, the backgage control unit 23 and the robot control unit 24 may not perform abutment control.

[0094] Furthermore, in the above-described embodiment, the backgauge 13 is described as having a first support portion 14A, a second support portion 14B, and a third support portion 14C, each of which is configured to be movable, but this is not limited to this, and the number of support portions 14 provided on the backgauge 13 may be four or more, or the number of support portions 14 provided on the backgauge 13 may be one.

[0095] In the above-described embodiment, the first support portion 14A, the second support portion 14B, and the third support portion 14C of the backgage 13 are respectively provided with the mounting portion 16 and the upper abutment portion 17, but this is not limitative, and the mounting portion 16 and the upper abutment portion 17 may not be provided on each support portion 14. Furthermore, the mounting portion 16 and the upper abutment portion 17 may be provided on only one of the support portions 14.

[0096] 1: Workpiece interference prevention system 10: Bending machine 11: Upper table 12: Lower table 13: Backgauge 14: Support section 15: Lower abutting section 16: Placement section 17: Upper abutting section 20: Control section 21: Backgauge position determination section 22: Robot position determination section 23: Backgauge control section 24: Robot control section D: Die F: Bending line P: Punch R: Workpiece holding robot W: Workpiece

Claims

1. A workpiece interference prevention system comprising: a bending machine equipped with an upper die, a lower die, and a backgage; a workpiece holding robot configured to be able to transport a workpiece between the upper die and the lower die; and a control unit that controls the bending machine and the workpiece holding robot, wherein the workpiece holding robot is provided forward of the upper die and the lower die, and the backgage is provided movably behind the upper die and the lower die, the control unit has a backgage control unit that controls the movement of the backgage, and a robot control unit that controls the movement of the workpiece holding robot, the backgage control unit is configured to move the backgage above or in front of the lower die before the workpiece is carried into or removed from between the upper die and the lower die, and the backgage control unit and the robot control unit operate the backgage and the workpiece holding robot to carry the workpiece into or out of between the upper die and the lower die, with the lower end of the workpiece supported from below by the backgage.

2. The workpiece interference prevention system according to claim 1, wherein the backgauge is provided with a mounting portion on which the lower end of the workpiece can be placed, and the backgauge control unit and the robot control unit operate the backgauge and the workpiece holding robot so as to carry the workpiece into or out of the space between the upper and lower dies with the lower end of the workpiece placed on the mounting portion.

3. The workpiece interference prevention system according to claim 2, wherein the control unit is configured to be able to perform the following: excess travel control, which operates at least one of the backgauge and the workpiece holding robot so that the placement portion of the backgauge is positioned forward of the lower end of the workpiece; temporary support control, which operates at least one of the backgauge and the workpiece holding robot in a vertical direction after the excess travel control so that the lower end of the workpiece is supported at a position rearward of the placement portion of the backgauge; and final support control, which operates at least one of the backgauge and the workpiece holding robot in a forward / backward direction after the temporary support control so that the lower end of the workpiece is placed on the placement portion.

4. A workpiece interference prevention system as claimed in claim 2 or 3, wherein the backgauge further comprises an upper abutment section provided behind the placement section, and the backgauge control section and the robot control section are configured to operate the backgauge and the workpiece holding robot to transport the workpiece into or out of the space between the upper and lower dies when the workpiece is abutted against the upper abutment section and the lower end of the workpiece is placed on the placement section.

5. A workpiece interference prevention system according to claim 1 or 2, wherein the back gauge comprises a first support portion that supports the front end of the workpiece and a second support portion that supports the side end of the workpiece.

6. A method for preventing workpiece interference, comprising: a moving step of moving the backgauge of the bending machine above or in front of the lower die before carrying the workpiece into or out of between the upper and lower dies of the bending machine; a supporting step of supporting the lower end of the workpiece from below on the backgauge after the moving step; and a transporting step of carrying the workpiece supported on the backgauge in the supporting step into or out of between the upper and lower dies of the bending machine.

7. A bending machine comprising: an upper die and a lower die; a backgage movably provided behind the lower die; and a control unit for controlling the movement of the backgage, wherein the control unit is configured to move the backgage above or in front of the lower die before a workpiece is carried into or removed from between the upper die and the lower die, and with the lower end of the workpiece supported by the backgage, carry the workpiece into or remove it from between the upper die and the lower die.

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