JP7745526B2 - Bending machine - Google Patents

Description

The present invention relates to a bending machine.

In bending machines such as press brakes, a technology is known in which an automatic die changer uses a device to automatically change 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 taking place while the automatic die changer is performing the die change operation.

The shutter needs to be opened and closed every time the mold is replaced, so manually opening and closing the shutter is a significant burden for the worker. Therefore, there is a need to automate the opening and closing of the shutter.

JP 2013-22645 A

When automating the opening and closing of shutters, especially the closing operation, care must be taken to ensure that the shutter does not interfere 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 account interference between the shutter and objects.

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 and which moves 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 that include an opening direction that opens the target area and a closing direction that shields the target area; and a detection unit that is attached to the edge of the leading edge of the shutter when the shutter moves in the closing direction and detects interference between the shutter and an object.

According to one aspect of the present invention, a detection unit that detects interference with an object is provided on the edge of the leading edge of the shutter. This makes it possible to properly detect interference between the shutter and an object even when the shutter closes automatically.

One aspect of the present invention is that it is possible to detect interference between the shutter and an object, providing specifications that are beneficial for the automatic closing operation of the shutter.

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 the bending machine according to this embodiment, showing a state in which the shutter is closed. FIG. 3 is an enlarged view of the main part of the shutter. 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. FIG. 5A is a diagram illustrating the detection unit. FIG. 5B is a diagram illustrating the detection unit. FIG. 6A is a diagram illustrating a main part of the center guide member. FIG. 6B is a diagram illustrating a main part of the side guide member. FIG. 7 is an explanatory diagram showing a modified example of the shutter.

The bending machine according to this embodiment will be described below with reference to the drawings.

Figure 1 is a front view schematically illustrating the configuration of a bending machine according to this embodiment, showing the shutter in an open state. Figure 2 is a front view schematically illustrating the configuration of a bending machine according to this embodiment, showing the shutter in a closed state. 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 Figures 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.

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 block the target area; and a detection unit 30 attached to the lower edge 24b of the shutter 24 when the shutter 24 moves downward, which detects interference between the shutter 24 and an object.

Next, the bending machine 1 will be described in detail. 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 sheet metal, through the cooperation of a lower die 2 and an upper die 4.

The bending machine 1 comprises a pair of side plates 10, a lower table 12, an upper table 14, and a table drive mechanism 16.

The pair of side plates 10 are 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 that moves 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 only needs to 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 remains fixed.

A lower mold holder 18 is provided above the lower table 12 to detachably hold a lower mold 2 such as a die. The lower mold holder 18 has a holder groove formed in the left-right direction into which the shank portion (base portion) of the lower mold 2 is inserted. The lower mold holder 18 has a clamping mechanism that secures the lower mold 2 in place.

An upper die holder 20 is provided below the upper table 14, which detachably holds an upper die 4 such as a punch. The upper die holder 20 has a holder groove formed in the left-right direction for inserting the shank portion (base portion) of the upper die 4. The upper die holder 20 has a clamping mechanism that secures the upper die 4.

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 multiple lower dies 2 and multiple upper dies 4. An opening is provided on the front of the apparatus housing 60, and a door 61 that can be opened and closed is provided at the opening.

The mold storage device 6 has multiple lower mold stockers that hold one or more lower molds 2, and the multiple 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 of the multiple 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.

The mold storage device 6 also has multiple upper mold stockers that hold one or more upper molds 4, and an upper mold station that is movable in the vertical and horizontal directions. The configuration of the upper mold stocker and upper mold station is the same as the configuration of the lower mold stocker and lower mold station.

As shown in FIG. 1, the bending machine 1 is equipped with left and right lower die replacement units 55L, 55R and left and right upper die replacement units 56L, 56R. Note that the lower die replacement units 55L, 55R and the left and right upper die replacement units 56L, 56R, as well as the lower guide 57 and upper guide 58 described below, are shown only schematically in FIG. 1.

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 the 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 left-right along the lower guide 57.

The configuration of the left and right upper mold replacement units 56L, 56R and the upper guide 58 is similar to the configuration of the left and right lower mold replacement units 55L, 55R and the lower guide 57 described above.

The bending machine 1 has a control device 100. The control device 100 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 primarily composed of a hardware processor such as a CPU (Central Processing Unit), memory, and various interfaces. The memory and various interfaces are connected to the hardware processor via a bus.

A specific computer program is installed on the computer. The hardware processor executes the computer program, causing the computer to perform multiple functions provided by the control device 100.

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 located in front of the upper table 14.

The upper cover 22 is located in front of the upper table 14. The upper cover 22 covers the front side of the shutter 24 when it is in the open position, as described below.

The shutter 24 is a plate-like member that has 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 that allows the target area behind the shutter 24 to be viewed.

The shutter 24 is attached to a fixedly positioned 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 the rear surface of the shutter 24 is provided with a guide that moves along the guide rail. The shutter 24 is guided by the guide rail, allowing it to move in the vertical direction.

The shutter 24 opens and closes a target area extending from the underside of the upper table 14 to the top of the lower table 12. This target area includes the areas where the lower mold 2 and 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 upper mold 4 are replaced, the upper table 14 is in its highest position.

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 Figure 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 blocked by the shutter 24. The shutter 24 also moves upward (in the opening direction) from the closed position and reaches the open position.

A shutter drive mechanism 28 is provided on the base plate to move 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.

Figure 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, a housing that covers the left side of the bending machine 1.

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 moves 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 Figure 1.

Figure 4 is a schematic diagram showing the main parts of the shutter and the detection unit when viewed from the rear. 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 and lower edges 24a and 24b of the shutter 24. In other words, the detection unit 30 is provided on the edge of the shutter 24 closest to the tip when the shutter 24 moves downward.

The detection unit 30 includes a detection frame 32, multiple guide members 34a, 34b, and a pair of detection bodies 36, 38. As shown in Figure 4, in this embodiment, seven guide members are exemplified as the multiple guide members 34a, 34b.

The detection frame 32 is positioned on the lower edge 24b of the shutter. The detection frame 32 extends along the lower edge 24b of the shutter and is provided across the entire area of the 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, 34b. The lower edge 32a of the detection frame 32 is positioned lower than the lower edge 24b of the shutter. In other words, when the shutter 24 is moving downward, the detection frame 32 interferes with the object before the lower edge 24b of the shutter. This allows the object to be properly detected when it is present in the target area.

The shielding plate 26 described above is fixed to the detection frame 32. In addition to 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.

The multiple guide members 34a, 34b guide the vertical movement of the detection frame 32, allowing the detection frame 32 to move relative to the shutter lower edge 24b. The multiple guide members 34a, 34b are spaced apart in the left-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 in symmetrical positions that are line-symmetrical about 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 are arranged in symmetrical positions.

Figures 5A and 5B are diagrams illustrating the detection unit. Figure 5A shows the normal state of the detection unit 30, and Figure 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 are basically identical in configuration, the following explanation will focus on the side guide member 34b.

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

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.

The shaft 342 moves up and down, 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.

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

Figure 6A is a diagram illustrating the main parts of the center guide member, and Figure 6B is a diagram illustrating the main parts of the side guide member. The base 340 is a box-shaped member with an upper surface, and the upper surface of the base 340 is provided with a shaft opening 340a into which the lower end of the shaft 342 is inserted. A round bar-shaped hinge pin 348 is inserted into the lower end of the shaft 342 so as to be perpendicular to the shaft 342. The hinge pin 348 supports the shaft 342 so that it can rotate.

Hinge openings 340b and 340c are provided on a pair of opposing front and rear wall surfaces that make up the base 340. The hinge pin 348 is inserted through the pair of hinge openings 340b and 340c, and both ends of the hinge pin 348 are supported by the pair of hinge openings 340b and 340c.

As shown in Figure 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 Figure 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.

As shown in Figures 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 Figure 4, the detection frame 32 is also maintained in a fixed position relative to the shutter lower edge 24b.

As shown in Figure 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 positioned 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.

As shown in Figures 5A and 5B, one of the detection bodies 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.

As shown in FIG. 5A, in the normal state of the detection unit 30, the pair of detection bodies 36, 38 are positioned 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 change. The control device 100 detects that the detection frame 32 has moved relative to the shutter lower edge 24b through the change in the sensor signal.

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 the start of the mold replacement operation, it controls the shutter drive mechanism 28 to move the shutter 24 downward. The control device 100 may determine the start of the mold replacement operation based on an operation signal input in response to an operation by an operator, or may autonomously determine the start of the mold replacement operation based on the fulfillment of a predetermined trigger condition.

A detection unit 30 is provided on the lower edge 24b of the shutter. As shown in Figure 5A, the detection frame 32 is in its 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.

On the other hand, if an object is present in the path of the shutter 24, the detection frame 32 of the detection unit 30 will abut against the object. The detection frame 32 will receive a reaction force from the object and will move upward from its initial position against its own weight and the pressing force of the pressing member. In other words, the detection frame 32 will move upward relative to the lower edge 24b of the shutter.

In conjunction with the upward movement of the detection frame 32, the shaft 342, stopper 346, and the other detection body 38 also move upward in unison. As the other detection body 38 moves away from the first 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.

The shielding plate 26 is also 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 changes the sensor signals output from the pair of detection bodies 36, 38.

Here, referring to Figure 4, we will explain the movement of the detection frame 32 when it interferes with an object. Assume that the interfering object is located 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 Figure 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 portion 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 located to the left or right of the center, they can respond to even slight tilts of the detection frame 32.

When an interfering object is unevenly distributed on either the left or right side, the reaction force applied by the object must be sufficiently large to raise the entire detection frame 32. However, with the method of this embodiment, the detection frame 32 is tilted at an angle, 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 by the object is small.

In contrast, as shown in FIG. 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.

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

Next, assume that the 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.

When the control device 100 determines that the sensor signals output from the pair of detectors 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.

On the other hand, if there is no change in the sensor signals output from the pair of detectors 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.

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 complete.

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 based on a signal output from the upper end switch, it controls the shutter drive mechanism 28 to stop the movement of the shutter 24.

The above series of operations completes the opening and closing operation of the shutter 24.

As such, 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. This makes it possible to properly detect interference between the shutter and an object even when the shutter closes automatically.

According to one aspect of the present invention, a detection unit 30 is provided on the lower edge 24b of the shutter to detect interference between the shutter 24 and an object. The detection unit 30 can properly detect interference between the shutter 24 and an object when the shutter 24 moves downward. This provides a useful specification for automatically opening and closing the shutter 24.

In this embodiment, the detection unit 30 includes a detection frame 32 arranged on the lower edge 24b of the shutter, multiple guide members 34a, 34b that guide the movement of the detection frame 32 in the vertical direction and move the detection frame 32 relative to the lower edge 24b of the shutter, and a sensor unit that detects the movement of the detection frame 32 relative to the lower edge 24b of the shutter.

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 allows for appropriate detection of interference with an object.

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 arranged at the center of the detection frame 32 and at multiple sets of symmetrical positions that are line-symmetrical about the center position.

With this configuration, the detection frame 32 is provided over the entire lower edge 24b of the shutter, making it possible to detect interference with an object across the entire shutter 24. Furthermore, multiple guide members 34a, 34b are positioned at a central position and multiple pairs of symmetrical positions, providing balanced guidance for the vertical movement of the detection frame 32. This allows the detection frame 32 to rise smoothly when interference with an object occurs, enabling proper detection of interference with the object.

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 attached to the shaft 342 and presses the detection frame 32 downward.

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 prevents the detection frame 32 from moving unexpectedly when the shutter 24 opens and closes. As a result, false detections by the detection unit 30 can be reduced.

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 perpendicular to the shaft 342 and rotatably supports the shaft 342. The base 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 located in 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 pairs of side guide members 34b located at symmetrical positions, the pair of hinge openings 340c are formed in a horizontally elongated oval shape that follows the lower edge 32a of the detection frame 32.

With this configuration, the side guide member 34b allows freedom of movement between the hinge opening 340c of the base portion 340 and the hinge pin 348, allowing left-right movement of the base portion 340 relative to the hinge pin 348. This allows the detection frame 32 to be tilted so that the left or right end of the detection frame 32 is raised. If 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 in an inclined manner. This allows for accurate detection of interference with an object, even if the object is unevenly distributed to the left or right of the detection frame 32.

In this embodiment, the sensor units are arranged on the left and right sides of the detection frame 32, centered around the central position.

With this configuration, the movement of the detection frame 32 can be properly detected even if only one of the left and right ends of the detection frame 32 moves upward. This allows for accurate detection of interference with an object.

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

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

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

With this configuration, the target area can 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, and can also be the horizontal direction.

7 is an explanatory diagram showing a modified example of the shutter. In the embodiment described above, the shutter 24 is sized to cover the left-right range of the bending machine 1. However, the shutter 24 may be extended to the right, making the door 61 of the die storage device 6 unnecessary . In other words, the shutter 24 may be a full-surface shutter that opens and closes the entire system including the bending machine 1 and the die storage device 6.

As described above, an embodiment of the present invention has been described. However, the descriptions and drawings that form part of this disclosure should not be understood as limiting this invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

DESCRIPTION OF SYMBOLS 1 Bending machine 2 Lower die 4 Upper die 6 Die 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 frame 34a Center guide member 34b Side guide member 36, 38 Detection body 55L, 55R Lower die exchange unit 56L, 56R Upper die exchange unit 100 Control device 340 Base portion 340a Shaft opening 340b, 340c Hinge opening 342 Shaft 344 Linear bushing 346 Stopper 348 Hinge pin W Plate-shaped workpiece

Claims (5)

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 include:
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 : 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,
The bending machine according to claim 1 , wherein 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 an edge of the detection frame. The bending machine according to claim 2 , wherein the sensor units are arranged on the left and right sides of the detection frame with the center position as the center. 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. The shutter is
The bending machine according to claim 1, which is configured to be movable in the vertical direction.