Bending machine

Abstract

To detect interference between a shutter provided on a front side of a bending machine and an object.SOLUTION: A bending machine 1 is equipped with a lower table 12 that has a lower mold holder 18, an upper table 14 that has an upper mold holder 20 and relatively vertically moves with respect to the lower table 12, a shutter 24 that opens / closes an object area from a lower side of the upper table 14 including the upper mold holder 20 to an upper side of the lower table 12 including the lower mold holder 18, a shutter driving mechanism 28 that moves the shutter 24 in an opening / closing direction, and a detection unit 30 that is provided at a lower edge portion of the shutter 24 when the shutter 24 moves in a closing direction, and detects interference between the shutter 24 and an object.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a bending machine. [Background technology]

[0002] In bending machines such as press brakes, a technique is known in which an automatic die changer automatically changes dies. For example, Patent Document 1 discloses a press brake equipped with a shutter that moves up and down in front of the upper table. This shutter can prevent objects from entering the area where the die change is being performed while the automatic die changer is changing the dies.

[0003] The shutter must be opened and closed every time a mold is replaced, so manually opening and closing the shutter places a heavy burden on the worker. Therefore, it is desirable to automate the opening and closing of the shutter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-22645 Summary of the Invention [Problem to be solved by the invention]

[0005] When automating the opening and closing of the shutter, especially the closing operation, it is necessary to consider how to prevent the shutter from interfering with objects. Bending machines are equipped with a light-based safety device that detects interference between the die and objects other than the workpiece during bending. However, because the shutter is located in front of the table on which the die is attached, it is difficult for the safety device to monitor the area around the shutter. In other words, to automate the closing operation of the shutter, specifications must take into consideration interference between the shutter and objects. [Means for solving the problem]

[0006] One aspect of the present invention is a bending machine comprising: a lower table having a lower die holder to which a lower die can be attached in the left-right direction; an upper table having an upper die holder to which an upper die can be attached opposite the lower die, the upper table moving up and down relative to the lower table; a shutter that opens and closes a target area from the underside of the upper table including the upper die holder to the upper side of the lower table including the lower die holder; a shutter drive mechanism that moves the shutter in opening and closing directions including an opening direction that opens the target area and a closing direction that shields the target area; and a detection unit provided on the edge of the tip of the shutter when the shutter moves in the closing direction that detects interference between the shutter and an object.

[0007] According to one aspect of the present invention, a detection unit that detects interference with an object is provided at the edge of the leading edge of the shutter, thereby making it possible to properly detect interference between the shutter and an object even when the shutter closes automatically. [Effects of the Invention]

[0008] According to one aspect of the present invention, interference between the shutter and an object can be detected, thereby providing specifications that are beneficial to the automatic closing operation of the shutter. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing a schematic configuration of a bending machine according to this embodiment, showing a state in which the shutter is open. [Figure 2] FIG. 2 is a front view schematically showing the configuration of the bending machine according to this embodiment, showing a state in which the shutter is closed. [Figure 3] FIG. 3 is an enlarged view of the main part of the shutter. [Figure 4] FIG. 4 is a schematic diagram showing the main parts of the shutter and the detection unit when the shutter is viewed from the rear side. [Figure 5A]FIG. 5A is a diagram illustrating the detection unit. [Figure 5B] FIG. 5B is a diagram illustrating the detection unit. [Figure 6A] FIG. 6A is a diagram illustrating a main part of a center guide member. [Figure 6B] FIG. 6B is a diagram illustrating a main part of the side guide member. [Figure 7] FIG. 7 is an explanatory diagram showing a modified example of the shutter. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the bending machine according to this embodiment will be described with reference to the drawings.

[0011] FIG. 1 is a front view schematically showing the configuration of a bending machine according to this embodiment, showing a state in which the shutter is open. FIG. 2 is a front view schematically showing the configuration of a bending machine according to this embodiment, showing a state in which the shutter is closed. In the following description, directions are defined as left-right, front-rear, and up-down. The left-right and front-rear directions correspond to two directions that are orthogonal to the horizontal direction, and the up-down direction corresponds to the vertical direction. In FIGS. 1 and 2, the front side of the paper corresponds to the front direction, and the back side of the paper corresponds to the rear direction. However, these directions are used merely for convenience in describing the configuration of the bending machine.

[0012] The bending machine 1 comprises a lower table 12 having a lower die holder 18 to which a lower die 2 can be attached in the left-right direction, an upper table 14 having an upper die holder 20 to which an upper die 4 can be attached so as to face the lower die 2 and which moves up and down relative to the lower table 12, a shutter 24 that opens and closes a target area from the underside of the upper table 14 including the upper die holder 20 to the upper side of the lower table 12 including the lower die holder 18, a shutter drive mechanism 28 that moves the shutter 24 in vertical directions including an upward direction to open the target area and a downward direction to shield the target area, and a detection unit 30 provided on a lower edge 24b of the shutter 24 when the shutter 24 moves downward to detect interference between the shutter 24 and an object.

[0013] Next, we will explain the details of the bending machine 1. The bending machine 1 is, for example, a press brake, and is a processing machine that performs bending on a plate-shaped workpiece W such as a metal plate by cooperation of a lower die 2 and an upper die 4.

[0014] The bending machine 1 includes a pair of side plates 10, a lower table 12, an upper table 14, and a table driving mechanism 16.

[0015] The pair of side plates 10 are disposed spaced apart in the left-right direction. A lower table 12 extending in the left-right direction is provided below the pair of side plates 10, and an upper table 14 extending in the left-right direction is provided above the pair of side plates 10. The upper table 14 is configured to be movable in the up-down direction. A table drive mechanism 16 for moving the upper table 14 in the up-down direction is provided above each side plate 10. The table drive mechanism 16 is, for example, a hydraulic cylinder, but may also be a servo motor. The upper table 14 may be movable relative to the lower table 12, and the bending machine 1 may be configured to move the lower table 12 in the up-down direction while the upper table 14 is fixed.

[0016] A lower mold holder 18 that detachably holds a lower mold 2 such as a die is provided above the lower table 12. A holder groove for inserting the shank portion (base portion) of the lower mold 2 is formed in the left-right direction in the lower mold holder 18. The lower mold holder 18 has a clamp mechanism that fixes the lower mold 2.

[0017] An upper die holder 20 that detachably holds an upper die 4 such as a punch is provided below the upper table 14. A holder groove for inserting the shank portion (base portion) of the upper die 4 is formed in the upper die holder 20 along the left-right direction. The upper die holder 20 has a clamp mechanism that fixes the upper die 4.

[0018] A die storage device 6 is provided adjacent to the right side of the bending machine 1. The die storage device 6 has an apparatus housing 60 for storing a plurality of lower dies 2 and a plurality of upper dies 4. An opening is provided in the front of the apparatus housing 60, and a door 61 that can be opened and closed is provided at the opening.

[0019] The mold storage device 6 has a plurality of lower mold stockers that hold one or more lower molds 2, and the plurality of lower mold stockers are lined up in the front-to-rear direction. The mold storage device 6 has a lower mold station that is movable in the up-down and front-to-rear directions. The lower mold station can be positioned at a predetermined lower mold exchange position by selecting any lower mold stocker from the plurality of lower mold stockers and moving the selected lower mold stocker in the up-down and front-to-rear directions. The lower mold exchange position is set at a position adjacent to the right side of the lower mold holder 18.

[0020] The mold storage device 6 also has a plurality of upper mold stockers that hold one or more upper molds 4, and an upper mold station that is movable in the vertical and front-to-rear directions. The configurations of the upper mold stocker and the upper mold station are the same as those of the lower mold stocker and the lower mold station.

[0021] 1, the bending machine 1 includes left and right lower die replacement units 55L, 55R and left and right upper die replacement units 56L, 56R. The lower die replacement units 55L, 55R and the left and right upper die replacement units 56L, 56R, as well as a lower guide 57 and an upper guide 58, which will be described later, are shown only schematically in FIG.

[0022] The left and right lower mold exchange units 55L, 55R exchange the lower mold 2 between the lower mold holder 18 and the mold storage device 6. Specifically, the left and right lower mold exchange units 55L, 55R move the lower mold 2 from a lower mold stocker positioned at the lower mold exchange position to the lower mold holder 18, and position the lower mold 2 in the lower mold holder 18. The left and right lower mold exchange units 55L, 55R are provided behind the lower table 12. A lower guide 57 extending in the left-right direction is provided behind the lower table 12. Each lower mold exchange unit 55L, 55R can move in the left-right direction along the lower guide 57.

[0023] The configurations of the left and right upper mold replacement units 56L, 56R and the upper guide 58 are similar to the configurations of the left and right lower mold replacement units 55L, 55R and the lower guide 57 described above.

[0024] The bending machine 1 has a control device 100. The control device 100 is a device that controls the operation of the bending machine 1. The control device 100 is a computer such as an NC (Numerical Control) device. The computer is mainly composed of a hardware processor such as a CPU (Central Processing Unit), a memory, and various interfaces. The memory and various interfaces are connected to the hardware processor via a bus.

[0025] A predetermined computer program is installed in the computer, and the computer executes the functions of the control device 100 by the hardware processor executing the computer program.

[0026] One of the features of this embodiment is that the bending machine 1 has an upper cover 22, a shutter 24, and a detection unit 30. The upper cover 22 and the shutter 24 are arranged in front of the upper table 14.

[0027] The upper cover 22 is located in front of the upper table 14. The upper cover 22 is a cover that covers the front side of the shutter 24 when it is in the open position, which will be described later.

[0028] The shutter 24 is a plate-like member having a rectangular shape that is long in the left-right direction when viewed from the front. The shutter 24 is provided with a transparent window portion 25 through which the target area behind the shutter 24 can be seen.

[0029] The shutter 24 is attached to a fixedly arranged base plate (not shown) and is located in front of the upper table 14. The base plate is provided with a guide rail that extends in the vertical direction, and a guide that moves along the guide rail is provided on the rear surface of the shutter 24. The guide of the shutter 24 is guided by the guide rail, allowing the shutter 24 to move in the vertical direction.

[0030] The shutter 24 opens and closes a target area that includes the area from the underside of the upper table 14 to the upper side of the lower table 12. This target area includes the areas where the lower mold 2 and the upper mold 4 are replaced by the left and right lower mold replacement units 55L, 55R and the left and right upper mold replacement units 56L, 56R, respectively. When the lower mold 2 and the upper mold 4 are replaced, the upper table 14 is at its highest position.

[0031] The shutter 24 moves back and forth in the vertical direction between an open position located above and a closed position located below. When the shutter 24 is in the open position, the target area is exposed (see FIG. 1). When the shutter 24 moves downward (in the closing direction) from the open position, the shutter 24 reaches the closed position. When the shutter 24 is in the closed position, the target area is shielded by the shutter 24. Furthermore, the shutter 24 moves upward (in the opening direction) from the closed position and reaches the open position.

[0032] The base plate is provided with a shutter drive mechanism 28 that moves the shutter 24 up and down. The shutter drive mechanism 28 is, for example, a pneumatic cylinder. The shutter drive mechanism 28 is controlled by a control device 100. The control device 100 receives signals output from an upper end switch that detects when the shutter 24 has reached the open position and a lower end switch that detects when the shutter 24 has reached the closed position.

[0033] 3 is an enlarged view of the main parts of the shutter. A shielding plate 26 is provided at the left end of the shutter 24. This shielding plate 26 moves up and down in conjunction with the shutter 24 to open and close a sensor opening 52a provided in a side guide 52, which is a housing that covers the left side of the bending machine 1.

[0034] The bending machine 1 is equipped with an angle sensor unit (not shown) for detecting the bending angle of the workpiece W. The angle sensor unit is moved along a sensor guide 50 extending in the left-right direction by an electric actuator such as a servo motor. When not in use, the angle sensor unit is housed in a side guide 52. When in use, the angle sensor unit can move freely on the sensor guide 50 by passing through a sensor opening 52a provided in the side guide 52. Note that the sensor guide 50 is not shown in FIG. 1.

[0035] 4 is a schematic diagram showing the main parts of the shutter and the detection unit when viewed from the rear side. The detection unit 30 detects interference between the shutter 24 and an object. The detection unit 30 is provided on the lower edge 24b (hereinafter referred to as the "lower shutter edge") of the upper edge 24a and lower edge 24b of the shutter 24. In other words, the detection unit 30 is provided on the edge on the leading edge side of the shutter 24 when the shutter 24 moves downward.

[0036] The detection unit 30 has a detection frame 32, a plurality of guide members 34a, 34b, and a pair of detection bodies 36, 38. As shown in Fig. 4, in this embodiment, seven guide members are exemplified as the plurality of guide members 34a, 34b.

[0037] The detection frame 32 is disposed on the shutter lower edge 24b. The detection frame 32 extends along the shutter lower edge 24b and is provided over the entire area of ​​the shutter lower edge 24b. The detection frame 32 hangs down from a mounting base 27 fixed to the underside of the shutter 24 via guide members 34a and 34b. The lower edge 32a of the detection frame 32 is positioned lower than the shutter lower edge 24b. In other words, when the shutter 24 moves downward, the detection frame 32 interferes with an object before the shutter lower edge 24b does. This allows the object to be properly detected when it is present in the target area.

[0038] The above-mentioned shielding plate 26 is fixed to the detection frame 32. In addition to the function of opening and closing the sensor opening 52a of the side guide 52, the shielding plate 26 also has the function of detecting interference between the shielding plate 26 and an object present in the sensor opening 52a.

[0039] The multiple guide members 34a, 34b guide the movement of the detection frame 32 in the up and down direction, and move the detection frame 32 relative to the shutter lower edge 24b. The multiple guide members 34a, 34b are arranged at intervals in the left and right direction. The guide member 34a is provided at the center of the detection frame 32 (hereinafter referred to as the "center guide member 34a"). Meanwhile, the guide members 34b are each arranged at symmetrical positions with respect to the guide member 34a (hereinafter referred to as the "side guide members 34b"). In this embodiment, a total of three sets of left and right side guide members 34b at symmetrical positions are arranged.

[0040] 5A and 5B are diagrams illustrating the detection unit. Fig. 5A shows the normal state of the detection unit 30, and Fig. 5B shows the state of the detection unit 30 when an object interferes. Since the center guide member 34a and the side guide member 34b basically have the same configuration, the following description will focus on the side guide member 34b.

[0041] The side guide member 34 b includes a base portion 340 , a shaft 342 , a linear bushing 344 , a stopper 346 , and a hinge pin 348 .

[0042] The base 340 is fixed to the lower edge 32a of the detection frame 32 with bolts or the like. The base 340 connects the lower end of the shaft 342 to the detection frame 32.

[0043] The shaft 342 moves up and down while being guided by the linear bushing 344. The linear bushing 344 is fixed to the mounting base 27. Because the mounting base 27 is fixed to the shutter 24, the shaft 342 moves up and down relative to the shutter 24. Therefore, the detection frame 32 connected to the lower end of the shaft 342 also moves up and down relative to the shutter 24.

[0044] A pressing member (not shown), such as a spring, is provided on shaft 342. Base 340 is pressed downward by the pressing member. Accordingly, detection frame 32 fixed to base 340 is also pressed downward. In addition to the pressing force from the pressing member, detection frame 32 is also subjected to a downward force due to its own weight.

[0045] Fig. 6A is a diagram illustrating the main parts of the center guide member, and Fig. 6B is a diagram illustrating the main parts of the side guide member. Base 340 is a box-shaped member with an upper surface, and the upper surface of base 340 is provided with shaft opening 340a into which the lower end of shaft 342 is inserted. A round bar-shaped hinge pin 348 is inserted into the lower end of shaft 342 so as to be perpendicular to shaft 342. Hinge pin 348 supports shaft 342 rotatably.

[0046] Hinge openings 340b, 340c are provided in a pair of wall surfaces facing each other in the front and rear direction that make up base portion 340. Hinge pin 348 is inserted through the pair of hinge openings 340b, 340c, and both ends of hinge pin 348 are supported by the pair of hinge openings 340b, 340c.

[0047] As shown in Fig. 6A, in the case of the center guide member 34a, the pair of hinge openings 340b are formed in a circular shape that follows the outer shape of the round bar-shaped hinge pin 348. On the other hand, as shown in Fig. 6B, in the case of the side guide member 34b, the pair of hinge openings 340c are formed in an oval shape that is elongated in the left-right direction.

[0048] 5A and 5B, a stopper 346 is provided at the upper end of the shaft 342. The stopper 346 prevents the shaft 342 from falling off the linear bushing 344. Therefore, as shown in FIG. 4, the detection frame 32 is also maintained at a fixed position relative to the shutter lower edge 24b.

[0049] 4, the pair of detectors 36, 38 are sensors that detect relative movement of the detection frame 32 with respect to the lower edge 24b of the shutter. The pair of detectors 36, 38 are disposed near the left and right ends of the shutter 24 and the detection frame 32, respectively, with the center of the shutter 24 and the detection frame 32.

[0050] 5A and 5B, one detection body 36 is attached to the mounting base 27. The other detection body 38 is attached to a stopper 346 integrated with the detection frame 32.

[0051] 5A, in the normal state of the detection unit 30, the pair of detection bodies 36, 38 are arranged so that the distance between them is a predetermined reference distance. When one detection body 36 moves away from the other detection body 38, the positional relationship between the pair of detection bodies 36, 38 changes, and the sensor signals output from the pair of detection bodies 36, 38 also change. The control device 100 detects the relative movement of the detection frame 32 with respect to the shutter lower edge 24b through the change in the sensor signal.

[0052] The operation of the shutter 24 and the detection unit 30 will be described below with reference to Figs. 1 to 6B. First, as shown in Fig. 1, the shutter 24 is initially in the open position. When the control device 100 determines that the mold exchange operation should be started, it controls the shutter drive mechanism 28 to move the shutter 24 downward. The control device 100 may determine the start of the mold exchange operation based on an operation signal input in response to an operation by an operator, or may determine that a predetermined trigger condition is met. to The start of the mold change operation may be determined autonomously based on this.

[0053] A detection unit 30 is provided on the lower edge 24b of the shutter. As shown in Fig. 5A, the detection frame 32 is in an initial position due to its own weight and the pressing force of the pressing member. At this time, the pair of detection bodies 36, 38 are positioned a reference distance apart.

[0054] On the other hand, when an object is present in the path of the shutter 24, the detection frame 32 of the detection unit 30 hits the object. The detection frame 32 receives a reaction force from the object and moves upward from the initial position against its own weight and the pressing force of the pressing member. In other words, the detection frame 32 moves upward relative to the lower edge 24b of the shutter.

[0055] In conjunction with the upward movement of the detection frame 32, the shaft 342, the stopper 346, and the other detection body 38 also move upward in conjunction with each other. As the other detection body 38 moves away from the one detection body 36, the distance between the pair of detection bodies 36, 38 becomes greater than the reference distance. This causes a change in the sensor signal output from the pair of detection bodies 36, 38.

[0056] In addition, the shielding plate 26 is fixed to the detection frame 32. Therefore, when a foreign object is present in the sensor opening 52a of the side guide 52, the detection frame 32 rises via the shielding plate 26. This causes a change in the sensor signals output from the pair of detection bodies 36, 38.

[0057] Referring to FIG. 4, the movement of the detection frame 32 when it interferes with an object will be described. Assume that the interfering object is positioned to the left or right of the center of the detection frame 32. In this case, a reaction force from the object is applied to the left or right side of the detection frame 32. As shown in FIG. 6B, the pair of hinge openings 340c in the side guide member 34b are formed in an oval shape that is elongated horizontally. This oval shape allows the base 340 fixed to the detection frame 32 to move relative to the hinge pin 348 in the left-right direction. This allows the detection frame 32 to assume an obliquely tilted position so that the end on the side where the object is present rises. At this time, the sensor signals output from the pair of detection elements 36, 38 at the raised end change. Because the pair of detection elements 36, 38 are positioned to the left or right of the center, they can respond to even slight tilts of the detection frame 32.

[0058] When an interfering object is unevenly located on either the left or right side, the reaction force applied from the object must be sufficiently large to raise the entire detection frame 32. On the other hand, according to the method of this embodiment, the detection frame 32 is tilted obliquely, so that even a small force can raise the end of the detection frame 32. This allows the detection frame 32 to move smoothly upward even when the reaction force applied from the object is small.

[0059] 6A, the pair of hinge openings 340b in the center guide member 34a are formed in a circular shape that follows the outer shape of the hinge pin 348. Because the center guide member 34a is located in the center position, even if the detection frame 32 tilts obliquely, the movement of the base portion 340 in the left-right direction is sufficiently small. For this reason, the pair of hinge openings 340b in the center guide member 34a do not need to be formed in an oval shape that is elongated in the left-right direction.

[0060] Additionally, the center guide member 34a restricts the left-right movement of the base portion 340, thereby restricting the horizontal movement of the detection frame 32 in the left-right direction. When the detection frame 32 moves horizontally in the left-right direction, the relative distance between the pair of detection elements 36, 38 shifts. As a result, even though the detection frame 32 has not moved upward, the distance between the pair of detection elements 36, 38 becomes greater than the reference distance. This may result in a change in the sensor signal output from the pair of detection elements 36, 38. In this regard, the center guide member 34a of this embodiment can restrict such left-right movement of the detection frame 32 due to the shape of the pair of hinge openings 340b.

[0061] Next, assume that an interfering object is located at the center of the detection frame 32. In this case, a reaction force from the object is applied to the center of the detection frame 32. As a result, the detection frame 32 is guided by the central center guide member 34a and seven side guide members 34b, and moves upward as a whole. As a result, the sensor signals output from the pair of detection bodies 36, 38 on both the left and right sides change.

[0062] When the control device 100 determines that the sensor signals output from the pair of detection bodies 36, 38 have changed due to interference with an object, it controls the shutter drive mechanism 28 to reverse the movement direction of the shutter 24 and move it upward. Then, when the control device 100 detects from the signal output from the upper end switch that the shutter 24 has reached the open position, it controls the shutter drive mechanism 28 to stop the movement of the shutter 24.

[0063] On the other hand, if there is no change in the sensor signals output from the pair of detection bodies 36, 38, the control device 100 controls the shutter drive mechanism 28 to continue the downward movement of the shutter 24. Then, when the control device 100 detects from the signal output from the lower end switch that the shutter 24 has reached the closed position, it controls the shutter drive mechanism 28 to stop the movement of the shutter 24.

[0064] When the shutter 24 reaches the closed position, the mold exchange operation is performed by the left and right lower mold exchange units 55L, 55R and the left and right upper mold exchange units 56L, 56R. When the desired lower mold 2 and upper mold 4 are placed in the lower mold holder 18 and upper mold holder 20, the mold exchange operation is completed.

[0065] When the control device 100 determines that the mold change operation is complete, it controls the shutter drive mechanism 28 to move the shutter 24 upward. Then, when the control device 100 detects that the shutter 24 has reached the open position by a signal output from the upper end switch, it controls the shutter drive mechanism 28 to stop the movement of the shutter 24.

[0066] The opening and closing operation of the shutter 24 is completed by the above-described series of operations.

[0067] According to this embodiment, a detection unit that detects interference with an object is provided on the edge of the leading edge of the shutter, making it possible to properly detect interference between the shutter and an object even when the shutter closes automatically.

[0068] According to one aspect of the present invention, the lower edge 24b of the shutter is provided with a detection unit 30 that detects interference between the shutter 24 and an object. The detection unit 30 can appropriately detect interference between the shutter 24 and an object when the shutter 24 moves downward. This provides a useful specification for automatic opening and closing of the shutter 24.

[0069] In this embodiment, the detection unit 30 includes a detection frame 32 arranged on the lower edge 24b of the shutter, a plurality of guide members 34a, 34b for guiding the movement of the detection frame 32 in the vertical direction and moving the detection frame 32 relative to the lower edge 24b of the shutter, and a sensor unit for detecting that the detection frame 32 has moved relative to the lower edge 24b of the shutter.

[0070] With this configuration, when the shutter 24 moves downward, the detection frame 32 bumps into an object, causing the detection frame 32 to move upward. At this time, the sensor unit consisting of the pair of detection bodies 36, 38 can detect the relative movement of the detection frame 32 with respect to the lower edge 24b of the shutter. This makes it possible to properly detect interference with an object.

[0071] In this embodiment, the detection frame 32 is provided along the entire lower edge 24b of the shutter, and multiple guide members 34a, 34b are respectively arranged at a central position of the detection frame 32 and at multiple sets of symmetrical positions that are linearly symmetrical about the central position.

[0072] With this configuration, the detection frame 32 is provided over the entire area of ​​the shutter lower edge 24b, making it possible to detect interference with an object over the entire area of ​​the shutter 24. Furthermore, the multiple guide members 34a, 34b are respectively arranged in a central position and in multiple pairs of symmetrical positions, making it possible to guide the vertical movement of the detection frame 32 in a balanced manner. This allows the detection frame 32 to rise smoothly when interference with an object occurs, making it possible to properly detect interference with an object.

[0073] In this embodiment, each of the multiple guide members 34a, 34b has a shaft 342 that guides the vertical movement of the detection frame 32, a base portion 340 that connects the lower end of the shaft 342 to the detection frame 32, and a pressing member that is provided on the shaft 342 and presses the detection frame 32 downward.

[0074] With this configuration, the detection frame 32 is pressed downward by the pressing member. When there is no interference with an object, this pressing force maintains a constant distance between the detection frame 32 and the shutter lower edge 24b. This makes it possible to prevent the detection frame 32 from moving unexpectedly when the shutter 24 opens and closes. As a result, it is possible to prevent erroneous detection by the detection unit 30.

[0075] In this embodiment, each of the multiple guide members 34a, 34b has a hinge pin 348 that is inserted into the lower end of the shaft 342 so as to be perpendicular to the shaft 342 and rotatably supports the shaft 342. The base portion 340 is provided with a pair of hinge openings 340b, 340c that support both ends of the hinge pin 348, and the hinge pin 348 is inserted into the pair of hinge openings 340b, 340c. In the case of the center guide member 34a that is disposed at the central position, the pair of hinge openings 340b are formed in a circular shape that follows the outer shape of the round bar-shaped hinge pin 348. In the case of multiple sets of side guide members 34b that are disposed at symmetrical positions, the pair of hinge openings 340c are formed in a horizontally elongated oval shape that follows the lower edge portion 32a of the detection frame 32.

[0076] According to this configuration, the side guide member 34b has a degree of freedom between the hinge opening 340c of the base portion 340 and the hinge pin 348, allowing the base portion 340 to move left and right relative to the hinge pin 348. This allows the detection frame 32 to be tilted so that the left end or the right end of the detection frame 32 is lifted. In cases where an object is unevenly distributed to the left or right of the detection frame 32, the detection frame 32 can be lifted with a simple force by moving the detection frame 32 so as to tilt. This allows accurate detection of interference with an object even when the object is unevenly distributed to the left or right of the detection frame 32.

[0077] In this embodiment, the sensor units are arranged on the left and right sides of the detection frame 32 with the center position as the center.

[0078] With this configuration, even if only one of the left and right ends of detection frame 32 moves upward, it is possible to properly detect the movement of detection frame 32. This makes it possible to accurately detect interference with an object.

[0079] In this embodiment, a shielding plate 26 is attached to the left and right ends of the detection frame 32 to open and close a sensor opening 52 a , which is an apparatus opening adjacent to the side of the shutter 24 .

[0080] According to this configuration, when the shielding plate 26 interferes with an object and moves upward, the detection frame 32 also moves upward in conjunction with the object. This allows the detection unit 30 to detect that an object has interfered with the shielding plate 26 without using a separate sensor.

[0081] In this embodiment, the shutter 24 is configured to be movable in the vertical direction.

[0082] This configuration allows the target area to be opened and closed in the vertical direction. This makes it possible to properly detect interference between the shutter 24, which moves in the vertical direction, and an object. Note that the shutter movement direction is not limited to the vertical direction, but may also be the horizontal direction.

[0083] 7 is an explanatory diagram showing a modified example of the shutter. In the above-described embodiment, the shutter 24 is sized to cover the range of the bending machine 1 in the left-right direction. However, it is also possible to extend the shutter 24 to the right and make the door 61 of the mold storage device 6 unnecessary. and That is, the shutter 24 may be a full-surface shutter that opens and closes the entire system including the bending machine 1 and the die housing device 6.

[0084] Although the embodiments of the present invention have been described above, the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure. [Explanation of symbols]

[0085] 1. Bending machine 2 Lower mold 4 Upper mold 6. Mold storage device 12 Lower table 14 Upper table 16 Table drive mechanism 18 Lower die holder 20 Upper die holder 22 Upper cover 24 Shutter 26 Shielding Plate 28 Shutter drive mechanism 30 Detection Unit 32 detection frames 34a Center guide member 34b Side guide member 36, 38 Detector 55L, 55R lower die change unit 56L, 56R upper die change unit 100 control device 340 Base 340a Shaft opening 340b, 340c Hinge opening 342 Shaft 344 Linear Bush 346 Stopper 348 Hinge Pin W Plate-shaped workpiece

Claims

1. a lower table having a lower die holder to which a lower die can be attached along the left-right direction; an upper table having an upper die holder to which an upper die can be attached so as to face the lower die, the upper table being movable up and down relative to the lower table; a shutter that opens and closes a target area from the lower side of the upper table including the upper mold holder to the upper side of the lower table including the lower mold holder; a shutter drive mechanism that moves the shutter in opening and closing directions including an opening direction that exposes the target area and a closing direction that shields the target area; a detection unit provided on an edge portion of the front end side of the shutter when the shutter moves in the closing direction, the detection unit detecting interference between the shutter and an object; The detection unit a detection frame disposed at the edge portion on the tip side; a plurality of guide members for guiding movement of the detection frame in the opening and closing direction and for moving the detection frame relative to the edge portion on the tip side; a sensor unit that detects relative movement of the detection frame with respect to the edge portion on the tip side; Including, The detection frame includes: The tip-side edge portion is provided along the entire area of ​​the tip-side edge portion, The plurality of guide members are The detection frame is arranged at a central position and at a plurality of pairs of symmetrical positions that are line-symmetrical about the central position, Each of the plurality of guide members is a shaft that guides movement of the detection frame in the opening and closing directions; a base portion that connects an end of the shaft to the detection frame; a pressing member provided on the shaft and configured to press the detection frame in the closing direction; A bending machine having:

2. Each of the plurality of guide members is a hinge pin that is inserted through an end of the shaft so as to be perpendicular to the shaft and that rotatably supports the shaft; a pair of hinge openings that support both ends of the hinge pin are provided in the base portion, and the hinge pin is inserted into the pair of hinge openings; In the case of the guide member disposed at the central position, the pair of hinge openings are formed in a circular shape that follows the outer shape of the hinge pin, which has a round bar shape, In the case of the plurality of sets of guide members arranged at symmetrical positions, the pair of hinge openings are formed in an oval shape that is horizontally elongated along the edge of the detection frame. The bending machine according to claim 1.

3. The sensor units are disposed on the left and right sides of the detection frame with the central position as the center. The bending machine according to claim 2.

4. A lower table having a lower die holder to which a lower die can be attached along the left-right direction; an upper table having an upper die holder to which an upper die can be attached so as to face the lower die, the upper table being movable up and down relative to the lower table; a shutter that opens and closes a target area from the lower side of the upper table including the upper mold holder to the upper side of the lower table including the lower mold holder; a shutter drive mechanism that moves the shutter in opening and closing directions including an opening direction that exposes the target area and a closing direction that shields the target area; a detection unit provided on an edge portion of the front end side of the shutter when the shutter moves in the closing direction, the detection unit detecting interference between the shutter and an object; The detection unit a detection frame disposed at the edge portion on the tip side; a plurality of guide members for guiding movement of the detection frame in the opening and closing direction and for moving the detection frame relative to the edge portion on the tip side; a sensor unit that detects relative movement of the detection frame with respect to the edge portion on the tip side; Including, A bending machine in which a shielding plate for opening and closing an apparatus opening adjacent to the side of the shutter is attached to the left and right ends of the detection frame.

5. The shutter is It is configured to be movable in the vertical direction. The bending machine according to claim 1.

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