Bending device and bending method using same

Abstract

The present invention provides a bending device and bending method that make it possible to shorten the time needed for die replacement and contribute to increased productivity. One aspect of the present invention is a bending device 1 that has a plurality of racks 3 that are fixed to a pair of side frames 2 and can carry an upper die, a transport unit 5 that has a transport unit upper die fixing mechanism 51 and is between the racks and a ram that has a ram upper die fixing mechanism 41, a back gauge 6 that is for positioning a workpiece, and a movement unit 7 that moves the back gauge independently of the racks. Another aspect of the present invention is a bending method for processing using a bending device that has a plurality of racks that are fixed to a pair of side frames and can carry an upper die, a ram that has an upper die fixing mechanism and can move up and down, a unit that transports between the racks and the ram, a back gauge that is for positioning a workpiece, and a unit that moves the back gauge independently of the racks, the bending method having a step for installing an upper mold, positioning a workpiece, and driving the ram into a lower die to press the workpiece and a step for unfastening and grasping an upper die that is fixed to the racks.

Description

Bending device and bending method using the same

[0001] The present invention relates to a bending device and a bending method using the same.

[0002] Generally, a bending device is equipped with an upper die (punch die) and a lower die (die die) that receives it, and the workpiece to be bent is placed between the two dies, and is then clamped with great force between the punch die and the die die, allowing the bending process to be performed on the workpiece.

[0003] However, in recent years, with increasing user needs and the increasing functionality of products, the variety of bending processes has become more pronounced, and it has become necessary to prepare multiple types of punches and dies for use in these processes.

[0004] However, the upper and lower dies, especially the upper die, may need to be replaced depending on the bending sequence, and the time required for replacing the upper die reduces productivity. Therefore, it is very important to reduce the time required for this replacement.

[0005] Regarding the above, as a known bending device, for example, Patent Document 1 below discloses a technology in which multiple movable arms with mold units attached are arranged in front of and behind a ram and the mold units are attached to the tip of the ram by moving the movable arms.Also, Patent Document 2 below discloses a press machine having a mold storage unit fixed to a backgage device and a mold exchange unit that is movable in the up-down direction and the back-and-forth direction and can be tilted.

[0006] JP 2015-223594 A JP 2003-136144 A

[0007] However, the technology described in Patent Document 1 has a problem in that a movable arm is required for each mold unit. Therefore, it is necessary to ensure a range of motion for each movable arm, and a drive device such as a cylinder is required for each movable arm. Therefore, the increase in mold units significantly increases the size and cost of the device, and there are still problems such as limited working space to avoid the range of motion of each movable arm.

[0008] Furthermore, in the technology described in Patent Document 2, the mold storage section is fixed to the backgauge, and the mold cannot be replaced while the backgauge device is in use, which means that there are still issues to be addressed in terms of reducing the time required for mold replacement.

[0009] In view of the above, an object of the present invention is to provide a bending apparatus and a bending method that can further reduce the time required for die replacement and contribute to improved productivity.

[0010] A bending device according to one aspect of the present invention that solves the above-mentioned problems comprises a pair of side frames, a plurality of racks fixed to the side frames and capable of placing an upper die, a ram that has an upper die fixing mechanism for a ram for fixing the upper die and is movable up and down, a transport unit that has an upper die gripping mechanism for a transport unit for gripping the upper die and transports the upper die gripping mechanism for the transport unit between the rack and the ram, a backgauge that positions the workpiece, and a backgauge moving unit that moves the backgauge independently of the plurality of racks.

[0011] In addition, in this respect, although not limited thereto, it is preferable that the racks are fixed to the side frames so that their installation positions are low along the direction away from the ram.

[0012] Also, in this respect, although not limited thereto, it is preferable that the conveying unit comprises an axial member, a rotation mechanism for rotating the axial member, and a movement mechanism for moving the axial member up and down and back and forth, and that multiple upper mold gripping mechanisms for the conveying unit are arranged around the axial member along the circumferential direction of the axial member.

[0013] Also, in this respect, although not limited thereto, it is preferable that the upper mold has a gripping protrusion on its side, and that the upper mold gripping mechanism for the transport unit grips the upper mold by grasping the gripping protrusion.

[0014] Furthermore, in this respect, although not limited thereto, it is preferable that all of the multiple racks are fixed to the side frame at a position above the ram upper mold fixing mechanism on the ram.

[0015] Also, from this perspective, although not limited to this, it is preferable to have a lower mold gripping mechanism that holds a lower mold corresponding to the upper mold attached to the ram, and a bed that holds the lower mold gripping mechanism.

[0016] In addition, in this respect, although not limited thereto, it is preferable to provide a lower mold slide unit that slides the lower mold gripping mechanism.

[0017] In addition, a bending method according to another aspect of the present invention is a bending method for bending a workpiece using a bending device having a pair of side frames, a plurality of racks fixed to the side frames and on which an upper die can be placed, a ram having an upper die fixing mechanism for a ram for fixing the upper die and movable up and down, a transport unit having an upper die holding mechanism for a transport unit for holding the upper die and transporting the upper die holding mechanism for a transport unit between the rack and the ram, a backgage for positioning the workpiece, and a backgage moving unit for moving the backgage independently of the plurality of racks, the bending method comprising: a press step in which a first upper die is attached to the upper die fixing mechanism for a ram of the ram, the workpiece is positioned by the backgage, and the ram is driven to press the workpiece in combination with a lower die; and during the press step, a transport unit upper die preparation and attachment step in which a second upper die fixed to the plurality of racks is removed from the rack and held by the upper die holding mechanism for a transport unit of the transport unit.

[0018] Also, in this respect, although not limited to this, it is preferable to have a rack upper mold return step in which the third upper mold held by the transport unit is removed from the transport unit and placed on the rack during the press step.

[0019] As described above, the present invention can provide a bending device and a bending method that can further reduce the time required for die replacement and contribute to improved productivity.

[0020] 1 is a diagram showing an outline of a bending device according to an embodiment when viewed obliquely from the front. FIG. 2 is a diagram showing an outline of a bending device according to an embodiment when viewed obliquely from the rear. FIG. 3 is a diagram showing an outline of a cross section of a bending device according to an embodiment. FIG. 4 is a diagram showing an outline of a specific structure of a rack in a bending device according to an embodiment. FIG. 5 is a diagram showing an outline of the arrangement of racks in a bending device according to an embodiment. FIG. 6 is a diagram showing an outline of the operation of attaching and removing a rack in a bending device according to an embodiment. FIG. 7 is a diagram showing the relationship between a rack in a bending device according to an embodiment and an upper die gripping mechanism for a transport unit of a transport unit. FIG. 8 is a diagram showing a specific example of an upper die in a bending device according to an embodiment. FIG. 9 is a diagram showing an outline of specific steps of bending a workpiece using an upper die and a lower die in a bending device according to an embodiment. FIG. 10 is a diagram showing an example of a gripping protrusion of an upper die in a bending device according to an embodiment. FIG. 11 is a diagram showing an outline of a ram drive unit in a bending device according to an embodiment. FIG. 12 is a diagram showing an outline of an upper die fixing mechanism for a ram in a bending device according to an embodiment. FIG. 13 is a diagram showing an outline of a transport unit in a bending device according to an embodiment. FIG. 14 is a diagram showing an outline of an upper die gripping mechanism for a transport unit in a bending device according to an embodiment. FIG. 1 is a diagram showing an outline of a backgage in a bending device according to an embodiment. FIG. 2 is a diagram showing an outline of a backgage moving unit in a bending device according to an embodiment. FIG. 3 is a diagram showing a specific example of a lower die in a bending device according to an embodiment. FIG. 4 is a diagram showing a specific example of a lower die according to an embodiment. FIG. 5 is a diagram showing an outline of a lower die gripping mechanism according to an embodiment. FIG. 6 is a diagram showing an outline of one step of a bending method according to an embodiment. FIG. 7 is a diagram showing an outline of one step of a bending method according to an embodiment.

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can be embodied in many different forms and is not limited to the specific examples described in the following embodiments.

[0022] FIG. 1 is a diagram showing an outline of a bending device (hereinafter referred to as "this device") 1 according to this embodiment when viewed from diagonally from the front, FIG. 2 is a diagram showing an outline of this device 1 when viewed from diagonally from the rear, and FIG. 3 is a schematic cross-sectional view for explaining the interior of this device 1.

[0023] As shown in these figures, the device 1 comprises a pair of side frames 2, a plurality of racks 3 fixed to the side frames 2 and capable of placing the upper mold PD, a ram 4 which has an upper mold fixing mechanism 41 for the ram for fixing the upper mold PD and which can move up and down, a transport unit 5 which has an upper mold gripping mechanism 51 for the transport unit for gripping the upper mold PD and transports the upper mold gripping mechanism 51 for the transport unit between the rack 3 and the ram 4, a backgauge 6 which positions the workpiece W, and a backgauge moving unit 7 which moves the backgauge 6 independently of the plurality of racks 3.

[0024] This device 1 can provide a bending device and bending method that can reduce the time required for die replacement and contribute to improved productivity. The operation of this device 1 and the resulting effects will become clear from the following description. This device 1 can use the area between the side frames 2 as the processing area; in other words, if the distance between the side frames 2 is increased, a larger workpiece W can be processed. Here, "up and down" means perpendicular to the installation surface G on which this device 1 is installed, specifically, along the vertical direction, with "up" meaning the direction away from the installation surface G and "down" meaning the direction toward the installation surface.

[0025] First, as described above, the device 1 has a pair of side frames 2. The side frames 2 are members that form the framework of the device 1, and literally function as frame members on the sides of the device 1, functioning as support members for the various members described below.

[0026] Furthermore, the device 1 preferably includes not only a pair of side frames 2, but also connecting members 21 for connecting the side frames 2. This makes it possible to reliably maintain the distance between the side frames 2. Note that the device 1 may also be configured to include cover members 22 that cover at least a portion of the top, bottom, front, and back surfaces in addition to the side frames 2. This separates the space that houses each component of the device 1, ensuring safety and protecting each component.

[0027] As described above, the apparatus 1 also has the rack 3. The rack 3 is fixed to the side frames 2 and is capable of carrying the upper mold PD. An example of the specific structure of the rack 3 is shown in Figure 4. The racks 3 are also provided opposite each other at the same height from the installation surface G of the side frames 2. This is because the upper mold PD has a horizontally elongated shape extending to the left and right, and therefore needs to be supported at both ends.

[0028] The structure of the rack 3 is not limited as long as it can place the upper fitting PD as described above and can remove the upper fitting PD as needed, but it is preferable that it has, for example, a support portion 31 for supporting the upper mold PD.

[0029] The support portion 31 of the rack 3 is not limited as long as it can support the upper mold PD as described above, but a preferred form is a generally L-shaped structure including a lower support portion 311 and a side support portion 312. The generally L-shaped structure makes it possible to support the lower surface and side surface of the upper mold PD, while also enabling the upper mold PD to be easily removed without having to be unnecessarily lifted up by sliding it laterally from the lower support portion 311. However, it is preferable that the lower support portion 311 be provided with a tip protrusion 313 that prevents it from easily falling off.

[0030] In the present apparatus 1, it is preferable that there be a plurality of racks 3, specifically the number of racks fixed to one side frame 2 (which is also the number of sets of racks provided in a pair of side frames 2). Although it is possible to have only one rack 3, the present apparatus 1 is premised on the replacement of multiple upper dies PD, so by providing multiple racks, it is possible to place and store unused upper dies PD. Specifically, it is preferable that there be two or more racks, preferably three or more, and even more preferably four or more, and this can be adjusted as appropriate depending on the size of the present apparatus 1 and the type of processing of the workpiece W expected.

[0031] As is clear from the above description, the workpiece W is the object to be bent by the apparatus 1. It is not limited to any particular object, but is typically a metal plate. The apparatus 1 bends the initially flat workpiece W between the upper die PD and the lower die DD, pressing it to create the desired shape. By performing this bending process multiple times, more complex shapes can be created. In particular, by changing the combination of the upper die PD and the lower die DD, even more complex shapes can be achieved.

[0032] Furthermore, in this apparatus 1, the multiple racks 3 are preferably fixed to the side frames so that their installation positions decrease in the direction away from the ram 4. FIG. 5 shows an example in which four racks 3 are arranged. In this manner, by arranging the multiple racks 3 with gaps between them and by installing them so that their positions decrease in the direction away from the ram 4, the upper mold PD can be easily placed and removed. More specifically, by gradually lowering the installation positions and providing steps, the side of the upper mold PD in the rear stage (farther from the ram) has a portion that does not overlap horizontally with the rack 3 in the front stage (closer to the ram), making it easy to grip the upper mold PD within this non-overlapping range. An outline of the operation in this case is shown in FIG. 6. The height of this non-overlapping portion is not particularly limited, but is preferably higher than the height of the upper mold gripping mechanism 51 for the transport unit in the transport unit 5, which will be described in detail later, more specifically, the distance from the upper end 511 of the upper mold holding mechanism 51 for the transport unit to the lower end 5121 of the upper mold insertion portion 512. In this way, the transport unit 5, specifically the upper mold gripping mechanism for the transport unit, will not interfere with the adjacent rack 3. An image of this case is shown in Figure 7.

[0033] Furthermore, in this device 1, the upper mold PD is used in combination with the lower mold DD, and although it is an essential component when operating this device 1, it is a component that can be replaced as appropriate depending on the type of bending processing, etc., and it may be preferable to remove it when this device 1 is not being operated, for example, during maintenance or transportation.

[0034] As described above, the upper die PD is used in combination with the lower die DD. Specifically, the upper die PD preferably has a convex portion PDB and a holder portion PDH. This convex portion PDB of the upper die PD engages with the concave portion DDD of the lower die DD, sandwiching the workpiece to be bent between them and bending it into the desired shape. The holder portion PDH holds the convex portion PDB and facilitates transport, and is a common part among multiple die PDs. That is, among multiple upper die PDs, the convex portion PDB has a different shape for each die, while the holder portion PDH is a common part. Figure 8 shows a specific example of the upper die PD, and Figure 9 shows an outline of the specific steps for actually bending a workpiece using the upper die PD and lower die DD. Note that while the above figures show specific examples of the upper die PD, the present invention is not limited to these examples, as it can be adjusted appropriately depending on the type of bending process, as described above.

[0035] As described above, the number of upper dies PD can be adjusted appropriately depending on the type and number of desired bending processes, and can be adjusted accordingly to correspond to the number of racks 3. Specifically, the number may be one, but is preferably two or more, more preferably three or more, and even more preferably four or more, but is not limited to this.

[0036] Furthermore, in the present apparatus 1, although not limited thereto, it is preferable that a gripping protrusion PDN be further formed on the holder portion PDH of the upper mold PD. The reason for this will be described in detail later, but by forming this gripping protrusion PDN, the upper mold PD can be stably attached to the upper mold gripping mechanism for the transport unit 51. An outline of this case is shown, for example, in FIG. 10 . As shown in this figure, it is preferable that a hole PDNB be formed in the gripping protrusion PDN. By forming this hole PDNB, it is possible to reliably hold the upper mold PD while positioning it in the upper mold holding mechanism for the transport unit 51 and the upper mold fixing mechanism for the ram 41, which will be described later. This portion will also be described in detail later.

[0037] As described above, the apparatus 1 also includes the ram 4. The ram 4 has a ram upper die fixing mechanism 41 for mounting the upper die PD, is vertically movable, and is located at the top front of the apparatus 1. By mounting the upper die PD on the ram 4 and moving it vertically, the distance between the upper die PD and the lower die DD can be adjusted, as described above, and the upper die PD and the lower die DD can be meshed together to achieve bending of the workpiece. Note that the ram upper die fixing mechanism 41 for fixing the upper die PD to the ram 4 is preferably formed near the lower end of the ram 4. This allows the convex portion PDB of the die PD to protrude below the lower end of the ram 4 and be meshed with the lower die DD.

[0038] The device 1 also includes a ram drive unit 9 that enables the ram 4 to move up and down. The ram drive unit 9 is not limited as long as it can control the up and down movement of the ram 4, but it is preferable that the ram drive unit 9 include, for example, a power mechanism 91, a shaft member 92 that is reciprocated by the power mechanism 91, a connecting member 93 that connects the shaft member 92 to the ram 4, and a fulcrum member 94 that serves as a fulcrum for the connecting member 93, as shown in Figure 11. With this configuration, the shaft member 92 moves up and down by the power mechanism 91, and this up and down movement is transmitted to the ram 4 via the fulcrum member 94, allowing the ram 4 to move up and down.

[0039] 12 shows a specific example of the ram upper die fixing mechanism 41. The ram upper die fixing mechanism 41 preferably includes an upper die insertion portion 411 and a pressing member 412 that presses the upper die PD inserted into the upper die insertion portion 411. This allows the upper die PD, more specifically, the gripping protrusions PDN of the upper die PD, to be inserted and stably held. As shown in this figure, the number of pressing members 412 is not limited as long as they can press the gripping protrusions PDN of the upper die PD inserted into the upper die insertion portion 411 to fix the upper die PD to the ram 4. However, for stable fixation, it is preferable to provide multiple pressing members distributed along the left-right direction of the ram 4.

[0040] Furthermore, it is also preferable that the ram 4 be provided with a ram upper die correction mechanism 42 in addition to the ram upper die fixing mechanism 41. As described above, the upper die PD has a shape that is long in the left-right direction, and therefore deflection (a gap between the ram 4 and the upper die PD) may occur in the middle portion. Therefore, in order to prevent this deflection, it is preferable to provide a ram upper die correction mechanism 42 that presses the upper die PD against the ram 4.

[0041] As described above, the present apparatus 1 also has the transport unit 5. The transport unit 5 has an upper mold gripping mechanism for transport unit 51 for mounting the upper mold PD, and transports the upper mold gripping mechanism for transport unit 51 between the rack 3 and the ram 4. By having the transport unit 5, the present apparatus 1 can remove the upper mold PD held on the rack 3 and mount it on the ram 4, and can also remove the upper mold PD mounted on the ram 4 and hold it on the rack 3. In other words, it becomes possible to replace the upper mold PD.

[0042] FIG. 13 is a schematic diagram of the transport unit 5 in the present apparatus 1. As described above, the transport unit 5 is not limited to any particular configuration as long as it can replace the upper mold PD. It includes a shaft member 52, a rotation mechanism 53 for rotating the shaft member 52, a movement mechanism 54 for moving the shaft member 52 up and down and back and forth, and a power mechanism 55 for driving the rotation mechanism 54 and the movement mechanism. This allows the rotation shaft 52 to freely rotate and move up and down and back and forth, allowing the upper mold PD to be easily transported, attached, and removed between the rack 3 and the ram 4. As is clear from the above description, the terms "front and back" refer to directions in the horizontal direction, with the direction away from the ram being "rear" and the direction toward the ram being "front." The terms "left and right" refer to directions in the horizontal direction perpendicular to the front and back directions, with the right and left directions defined as the right and left, respectively, when viewing the present apparatus 1 from the front.

[0043] FIG. 14 also shows an outline of the upper mold gripping mechanism 51 for the transport unit in the present apparatus 1. The upper mold gripping mechanism 51 for the transport unit has an upper mold insertion section 512 into which the upper mold PD, specifically the holding protrusions PDN of the upper mold PD, is inserted. The upper mold PD can be securely held by inserting and pressing the holding protrusions PDN of the upper mold into the upper mold insertion section 512, and can be removed by releasing the upper mold PD. The upper mold gripping mechanism 51 for the transport unit preferably includes a pressing member 513 for pressing the upper mold PD. Using the pressing member 513, the upper mold PD can be pressed and fixed within the upper mold insertion section 512, thereby enabling the gripping protrusions PDN of the upper mold PD to be securely grasped. Furthermore, as described above, if a hole PDNB is formed in the gripping protrusions PDN of the upper mold PD, the tip of the pressing member 513 preferably has a protrusion 5131 that can be inserted into the hole PDNB. Forming the convex portion 5131 in this manner has the advantage that, when the convex portion 5131 is inserted into the position of the hole PDNB, the positions of the upper mold PD and the mold gripping mechanism for the transport unit 51 can be reliably determined. Furthermore, in this case, it is preferable that the hole PDNB has a stepped shape, and the convex portion 5131 also has a stepped shape to match this. This prevents misalignment and ensures reliable positioning. Note that the height, etc. of the upper mold gripping mechanism for the transport unit 51 in the transport unit is adjusted, and the rack 3 is fixed to the side frame 2 with a gap and an additional step, so that when attempting to grip the upper mold placed on the rack 3, it is preferable that it does not come into contact with the lower end of the previous stage of the rack 3.

[0044] Furthermore, it is preferable that multiple upper mold gripping mechanisms 51 for the transport unit are arranged along the circumferential direction of the shaft member 52. Here, "circumferential direction" means the direction along the trajectory of movement that occurs when the shaft member 52 is rotated. In this embodiment, arranging multiple upper mold gripping mechanisms 51 for the transport unit has the advantage that multiple upper molds can be held, transported, and attached / detached at once by rotating the shaft member 52. An outline of the operation in this case is shown in Figure 15. In this case, it is also preferable that multiple upper mold gripping mechanisms 51 for the transport unit are arranged in the same direction along the circumferential direction. This ensures that the molds are always oriented in the same direction when the shaft member 52 is rotated. The number of upper mold gripping mechanisms 51 is not limited as long as they can hold the molds without touching each other. Four or three mechanisms may be used, but two mechanisms are preferred. By using two mechanisms, one mechanism can be used to install the molds on the ram 4 and the other mechanism can be used to remove the molds from the ram 4 and return them to the rack 3.

[0045] As is clear from the diagram, in this apparatus 1, although not limited thereto, each of the multiple racks 3 described above is fixed to the side frame at a position above the mounting position of the upper mold PD on the ram 4. Preferably, the lower end of the ram 4 (or the lower end of the lowest rack 3 if multiple racks are present) is positioned above the upper end of the ram upper mold fixing mechanism 41 on the ram 4. This arrangement allows the upper mold PD to be attached to the rack 4 without further lowering the shaft member 52 of the transport unit 5 when the upper mold PD is removed from the ram 4. This not only minimizes the transport route of the upper mold but also prevents interference with the movement of the backgauge movement unit 7 (described below). Furthermore, having the multiple racks 3 positioned above the ram 4 is useful because it allows for sufficient operating space for the transport unit 5, specifically, the rotational space for the rotation shaft 52.

[0046] As described above, the present device 1 also has a back gauge 6. The back gauge 6 is used to position the workpiece. Figure 16 shows an outline of the back gauge 6. The provision of the back gauge 6 has the advantage that it is possible to determine the insertion position of the workpiece W relative to the present device 1, thereby enabling the desired bending process to be achieved.

[0047] As described above, the apparatus 1 also includes the backgage movement unit 7. The backgage movement unit 7 moves the backgage independently of the multiple racks. By providing the backgage movement unit 7, the insertion position of the workpiece W can be determined, thereby achieving the desired bending process.

[0048] Furthermore, the structure of the backgage movement unit 7 of the present device 1 is not limited, but is preferably configured to include, for example, a forward / backward movement mechanism 71 for moving the backgage forward / backward, a left / right movement mechanism 72 for moving it left / right, and a power source 73 for moving these, as shown in Figure 17. This makes it possible to install the backgage in a desired position. In particular, according to the present device 1, the rack 3 and the transport unit 5 are provided as separate components, and therefore can move independently without being linked to their movements, thereby shortening the time required for mold replacement and contributing to improved productivity.

[0049] Furthermore, although not limited thereto, the present apparatus 1 preferably includes a lower mold gripping mechanism 81 for holding a lower mold DD corresponding to the upper mold PD attached to the ram 4, and a bed 8 for holding the lower mold gripping mechanism 81. FIG. 18 shows a specific example of the lower mold DD, and FIG. 19 shows an outline of the lower mold gripping mechanism 81. The bed 8 also serves as a member covering the lower front surfaces of a pair of side frames. As is clear from the above description, the lower mold DD corresponds to the upper mold PD, and is formed with a recessed portion DDD corresponding to the protruding portion PDB of the upper mold PD. The lower mold gripping mechanism is attached to the bed 8, and its structure can generally be similar to that of the ram upper mold fixing mechanism 41 described above.

[0050] Furthermore, the present device 1 preferably includes a lower mold slide unit 10 that slides the lower mold gripping mechanism 81. In this embodiment, multiple upper molds PD are provided, and by appropriately switching these, the types of processing performed by the upper molds PD can be increased. However, the lower mold DD must also be provided with recesses that match the upper molds PD. However, the lower mold DD is pre-formed with multiple recesses that match the convex portions of multiple upper molds, and can be accommodated by simply slightly shifting the position of the lower mold DD without having to change the lower mold DD. Therefore, by providing the lower mold slide unit 10, the same effect as mold replacement can be achieved. Figure 20 shows an outline of the plate mold slide unit 10.

[0051] The structure of the lower mold slide unit 10 in the present device 1 is not particularly limited, but it is preferable that it has, for example, a power mechanism 101 and a moving member 102 connected to the power mechanism 101 and moves back and forth to move the lower mold gripping mechanism 81. This allows the lower mold to be moved in the forward and backward directions.

[0052] (Bending method) Furthermore, as is clear from the configuration of the present device 1 described above, by using the present device 1, it is possible to realize a bending method that can reduce the time required for changing dies when bending a workpiece, thereby contributing to improved productivity. That is, the method for bending a workpiece according to this embodiment (hereinafter referred to as "this method") is a bending method for bending a workpiece using a bending device including a pair of side frames, a plurality of racks fixed to the side frames and capable of mounting an upper die, a ram having a ram upper die fixing mechanism for mounting the upper die and movable up and down, a transport unit having a transport unit upper die gripping mechanism for mounting the upper die and transporting the transport unit upper die gripping mechanism between the rack and the ram, a backgage for positioning the workpiece, and a backgage movement unit for moving the backgage independently of the plurality of racks, and includes (S1) a press step in which a first upper die is mounted on the ram upper die fixing mechanism of the ram, the workpiece is positioned by the backgage, and the ram is driven to press the workpiece in combination with a lower die, and during this press step, (S2) a transport unit upper die preparation and mounting step in which a second upper die mounted on the plurality of racks is removed from the rack and mounted on the transport unit upper die gripping mechanism of the transport unit. An outline of the operations in this case is shown in Figure 21.

[0053] More specifically, this method includes a press step in which the workpiece is pressed using the apparatus 1. During this step, the upper die PD held by the rack 3 can be attached to the upper die gripping mechanism for the transport unit. As a result, the upper die PD can be attached to the upper die gripping mechanism for the transport unit without interrupting the press step, allowing preparation for the next die change. This allows multiple processes to be performed in parallel, thereby reducing process time. Note that although the terms "first die" and "second die" are used here as ordinal numbers to distinguish between multiple dies and have no technical meaning, the first die is the upper die used for pressing in the press step, and the second die is the upper die prepared for use in the next press step.

[0054] As described above, this method includes the step (S1) of attaching the first upper die to the ram upper die fixing mechanism of the ram, positioning the workpiece using a back gauge, and driving the ram to press the workpiece in combination with the lower die, thereby making it possible to bend the workpiece W into a desired shape.

[0055] This method also includes, during the pressing step, (S2) a transport unit upper die preparation and mounting step in which the second upper die mounted on the plurality of racks is removed from the rack 3 and mounted on the transport unit upper die gripping mechanism 51 of the transport unit 5. That is, in this method, while the pressing step is being performed, it is possible to transport the upper die required for the next pressing step by the transport unit and prepare it for mounting on the rack 3. In other words, it is possible to significantly shorten the process.

[0056] Furthermore, although not limited to this, it is preferable that this method includes, during the pressing step, an on-rack mold returning step (S3) in which the third upper mold attached to the transport unit is removed from the transport unit and attached to the rack 3. An outline of the operation in this case is shown in Figure 22.

[0057] More specifically, this method includes a press step in which the apparatus 1 is used to press a workpiece, and during this step, the upper die PD held by the transport unit can be returned to the rack 3. As a result, the upper die PD can be returned to the rack 3 and the next operation can be performed without interrupting the press step, allowing multiple processes to be performed in parallel. Note that although the term "third die" is used here, the "third" in this term, like the above-mentioned "first" and "second," is merely an ordinal number used to distinguish between multiple dies and has no technical meaning. However, the third die is an upper die that has been used in the press step, is returned to the rack, and is held there until the next use.

[0058] As described above, the present invention provides a bending device and a bending method that can shorten the time required for die replacement and contribute to improving productivity. Specifically, this device and method allows the preparation of the upper die to be used in the next press step to be carried out in parallel during one press step, and also allows the upper die used in the previous press step to be returned to the rack. This allows for a significant reduction in work time.

[0059] The present invention has industrial applicability as a bending device and a bending method using the same.

[0060] DESCRIPTION OF SYMBOLS 1...Bending device 2...Side frame 3...Rack 31...Support part 4...Ram 41...Upper mold fixing mechanism for ram 5...Transport unit 51...Upper mold gripping mechanism for transport unit 52...Shaft member 53...Rotation mechanism 54...Movement mechanism 55...Power 6...Backgauge 7...Backgauge movement unit 8...Bed 81...Lower mold gripping mechanism 9...Ram drive unit 91...Power 92...Shaft member 93...Connecting member 94...Fulcrum member 10...Lower mold slide unit SF...Slide frame PD...Upper mold PDB...Convex part PDS...Side surface PDN...Gripping protrusion DD...Lower mold DDD...Concave part

Claims

1. A bending device comprising: a pair of side frames; a pair of racks fixed to each of the pair of side frames and capable of placing one upper die thereon; a ram having an upper die fixing mechanism for a ram for fixing the upper die and movable up and down; a transport unit having an upper die gripping mechanism for a transport unit for gripping the upper die and transporting the upper die gripping mechanism for a transport unit between the pair of racks and the ram; a backgage for positioning a workpiece; and a backgage moving unit for moving the backgage independently of the pair of racks, wherein a plurality of pairs of racks are provided, the plurality of pairs of racks are fixed to the side frames so that their installation positions are low in a direction away from the ram, and adjacent pairs of racks have portions that do not overlap in the horizontal direction, and gripping protrusions are attached to the side surfaces of the upper die, and the gripping protrusions are arranged on the pair of racks at portions that do not overlap with the adjacent pair of racks in the horizontal direction, The upper mold gripping mechanism for the transport unit grips the upper mold by grasping the gripping protrusion from the side of the upper mold, the transport unit comprises a shaft member, a rotation mechanism for rotating the shaft member, and a movement mechanism for moving the shaft member up and down and back and forth, and the upper mold gripping mechanism for the transport unit is a bending device in which multiple mechanisms are arranged around the shaft member along the circumferential direction of the shaft member.

2. A bending device according to claim 1, wherein each of the plurality of pairs of racks is fixed to the side frame at a position on the ram above the ram upper die fixing mechanism.

3. A bending device according to claim 1, comprising: a lower die holding mechanism for holding a lower die corresponding to the upper die attached to the ram; and a bed for holding the lower die holding mechanism.

4. A bending apparatus according to claim 3, further comprising a lower die slide unit for sliding said lower die holding mechanism.

5. A bending device having a pair of side frames, a pair of racks fixed to each of the pair of side frames and capable of placing one upper die thereon, a ram having an upper die fixing mechanism for a ram for fixing the upper die and movable up and down, a transport unit having an upper die gripping mechanism for a transport unit for gripping the upper die and transporting the upper die gripping mechanism for a transport unit between the pair of racks and the ram, a backgage for positioning a workpiece, and a backgage moving unit for moving the backgage independently of the pair of racks, wherein a plurality of pairs of racks are provided, and the plurality of pairs of racks are arranged in a direction away from the ram so that their installation positions are lowered. a bending method for bending a workpiece using a plurality of bending devices arranged around a shaft member along the circumferential direction of the shaft member, the upper die being fixed to a side frame, the pair of adjacent racks having portions that do not overlap with each other in the horizontal direction, the upper die having a gripping protrusion on a side surface, the gripping protrusion being arranged at a portion of the pair of racks that does not overlap with the adjacent pair of racks in the horizontal direction, the upper die gripping mechanism for the transport unit gripping the gripping protrusion from the side surface of the upper die, the transport unit having a shaft member, a rotation mechanism that rotates the shaft member, and a movement mechanism that moves the shaft member up and down and back and forth, A bending method comprising a press step in which a first upper die is attached to a ram upper die fixing mechanism of a ram, the work is positioned by a back gauge, and the ram is driven to press the work in combination with a lower die, and a transport unit upper die preparation and attachment step in which, during the press step, second upper dies fixed to the plurality of pairs of racks are removed from the pair of racks and held by a transport unit upper die holding mechanism of a transport unit.

6. A bending method as described in claim 5, further comprising a rack mold return step of removing the third upper mold held by the transport unit from the transport unit and placing it on the rack during the pressing step.

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