Press system and transfer device

Abstract

Provided is a press system capable of removing a workpiece from the lower side of a die and capable of miniaturizing and simplifying a device. The press system includes: a plurality of press-working parts each having a die 71 and a punch; and a transfer device 76 for conveying a workpiece processed by one of the press-working parts to the press-working part of a subsequent process. The transfer device 76 includes: a plurality of conveyance fingers 77 for sandwiching the workpiece in a direction orthogonal to a conveyance direction of the workpiece; slide bars (78A, 78B) on which the plurality of conveyance fingers 77 are installed; a drive part for driving the slide bars (78A, 78B) back and forth; stays 80 extending from the slide bars (78A, 78B) toward a lower side of a specific die 71A; and under-die removal fingers 81 which are installed on the stays 80 and which sandwich the workpiece moved to the lower side of the specific die 71A.

Description

Press systems and transfer devices

[0001] The present invention relates to a press system and a transfer device used in the press system.

[0002] There is known a press system that includes multiple press working sections, each having a die and a punch, and performs press drawing on a workpiece multiple times. For example, Patent Document 1 discloses a press system that includes a transfer device that transports a workpiece that has been processed in one of the multiple press working sections to a press working section for a next process.

[0003] The press system of Patent Document 1 includes a workpiece removal device 40 for removing a workpiece that has passed through a die of a final-stage press working unit among multiple press working units. The workpiece removal device 40 includes a fixed base 41, a pair of first movable bases 43, a pair of second movable bases 44, a pair of arms 50, a ball screw mechanism 60, a forward / backward drive unit 63, a pair of opening / closing drive units 52, and the like. The fixed base 41 is fixed to a frame 11 that supports a ram 14 and a bolster 16 and is provided so as to protrude from the outer surface of the frame 11. The pair of first movable bases 43 are supported by the fixed base 41 so as to be movable in a first horizontal direction and are arranged side by side in a second horizontal direction. The pair of second movable bases 44 are supported by the pair of first movable bases 43 so as to be movable in the second horizontal direction. The pair of arms 50 are provided so as to extend from the pair of second movable bases 44 toward the bolster 16 in the first horizontal direction. The ball screw mechanism 60 is supported on the fixed base 41 above the first movable base 43 and the second movable base 44. The front-rear drive unit 63 drives the ball screw mechanism 60 to move the pair of arm units 50 between a forward position within the frame 11 and a backward position spaced apart from the frame 11 in the first horizontal direction. The pair of opening / closing drive units 52 are connected to the pair of second bases 44 and move the pair of arm units 50 between a closed position where the workpiece is clamped and an open position spaced apart from the workpiece.

[0004] Patent No. 6626234 specification

[0005] If the workpiece that has been subjected to press drawing could be removed from below the die, it would be possible to remove the workpiece without having to pass it from below the die again. This would prevent the workpiece from being damaged by passing it from below the die again. Therefore, it is desirable to realize an apparatus configuration that allows the workpiece to be removed from below the die. It is even more desirable to be able to remove the workpiece from below the die as described above, while also achieving a compact and simplified apparatus.

[0006] The present invention has been made in consideration of the above-mentioned situation, and aims to provide a press system and a transfer device that can remove a workpiece from below the die and that can achieve a smaller and simpler device.

[0007] (1) A press system of the present invention is a press system that includes a plurality of press working sections, each having a die and a punch, and performs press drawing on a workpiece multiple times, and further includes a transfer device that transports the workpiece processed in one of the plurality of press working sections toward a press working section for a next process, and the transfer device is characterized by having: a plurality of transport fingers arranged to hold the workpiece from both sides in a direction perpendicular to the transport direction of the workpiece; a pair of slide bars that extend along the transport direction and on which the plurality of transport fingers are installed; a drive unit that drives the slide bar back and forth along the transport direction; a stay that extends from the slide bar toward the underside of a specific die that is the die of one of the plurality of press working sections; and an under-die removal finger that is installed on the stay and holds the workpiece that has passed through the forming hole of the specific die and moved to the underside of the specific die.

[0008] According to the press system described in (1) above, a stay attached to a reciprocating slide bar is provided with a plurality of transport fingers for clamping a workpiece, and the stay extends toward the underside of a specific die. The stay is also provided with below-die removal fingers for clamping a workpiece that has moved to the underside of the specific die. Therefore, by clamping a workpiece that has passed through the specific die with the below-die removal fingers and driving the slide bar, the workpiece can be removed from the underside of the specific die. According to the press system described in (1) above, the slide bar of the transfer device is provided with a stay extending from the slide bar to the underside of the specific die, and the below-die removal fingers are attached to the stay, making it possible to remove a workpiece from the underside of the specific die using a small and simple mechanism.

[0009] As described above, according to the press system described in (1) above, the workpiece can be removed from below the die, and the device can be made smaller and simpler.

[0010] (2) In the press system of the present invention, it is more preferable that the press processing unit having the specific die has a specific die holder that supports the specific die, and the specific die holder has an opening into which the stay is inserted.

[0011] According to the press system described in (2) above, an opening for inserting a stay is provided in a specific die holder that supports a specific die from which a workpiece is removed from below, so that the stay can be easily inserted below the specific die.

[0012] (3) In the press system of the present invention, it is more preferable that the specific die holder is formed in a frame shape that supports the specific die.

[0013] According to the press system described in (3) above, the specific die holder is formed in a frame shape that supports the specific die, so that a wide opening for inserting the stay can be formed. Furthermore, because the specific die holder has a frame shape, it can be structured with legs on both sides of the opening, so that the specific die can be stably supported even if an opening is provided in the specific die holder.

[0014] (4) In the press system of the present invention, it is more preferable that the stay has a member fixed to the slide bar and extending from the slide bar toward below the specific die.

[0015] According to the press system described in (4) above, the stay extending from the slide bar to the underside of the specific die and on which the below-die removal finger is installed can be configured with a simple structure that includes a member fixed to the slide bar and extending from the slide bar toward the underside of the specific die, thereby enabling further miniaturization and simplification of the device.

[0016] (5) It is more preferable that the press system of the present invention further comprises a lower die set on which the plurality of press working sections, each having a die and a die holder supporting the die, are placed, the die holders of the plurality of press working sections are placed on the lower die set, a step is formed in the lower die set so that the height position of the portion on which the specific die holder is placed is lower than the height position of the portion on which the die holder of the press working section of a process earlier than the press working section having the specific die holder is placed, and the height dimension of the specific die holder is set so that the height position of the upper end surface of the specific die holder matches the height position of the die holder of the press working section of a process earlier than the press working section having the specific die holder.

[0017] According to the press system described in (5) above, the height of the upper end surfaces of the specific die holder and the die holder for the preceding process are the same, and a step is provided in the lower die set where the specific die holder is placed. This allows a wide vertical space for inserting a stay to be formed in the specific die holder that supports the specific die from which the workpiece is removed from below. This makes it easy to insert the stay from below the specific die.

[0018] (6) It is more preferable that the press system of the present invention further comprises a lower die set on which the plurality of press working sections, each having a die and a die holder supporting the die, are placed, the die holders of the plurality of press working sections are placed on the lower die set, the specific die holder is arranged so that the height position of the upper end surface matches that of the die holder of the press working section of the process earlier than the press working section having the specific die holder, and the height dimension of the die holder of the press working section of the process earlier than the press working section having the specific die holder is set to match the height dimension of the specific die holder.

[0019] According to the press system described in (6) above, the heights of the upper end surfaces of the specific die holder and the die holder for the front process are the same, and the height dimension of the die holder for the front process is set to match the height dimension of the specific die holder. Therefore, the die holder for the front process and the specific die holder can be manufactured with the same external shape. Furthermore, by appropriately setting the height dimensions of the die holder for the front process and the specific die holder to be high, a wide vertical space for inserting the stay can be formed in the specific die holder, making it easy to insert the stay from below the specific die. Furthermore, by thinning the thickness of the upper wall of the specific die holder and setting the height of the space inside the specific die holder to be high, a wide vertical space for inserting the stay can be formed in the specific die holder, making it easy to insert the stay from below the specific die.

[0020] (7) The transfer device of the present invention is a transfer device used in a press system having a plurality of press working sections each having a die and a punch and performing press drawing on a workpiece multiple times, and transports the workpiece processed in one of the plurality of press working sections toward the press working section for the next process, characterized in that it has: a plurality of transport fingers arranged to clamp the workpiece from both sides in a direction perpendicular to the transport direction of the workpiece; a pair of slide bars arranged to extend along the transport direction and on which the plurality of transport fingers are installed; a drive unit that drives the slide bar back and forth along the transport direction; a stay extending from the slide bar toward the underside of a specific die that is the die of one of the plurality of press working sections; and an under-die removal finger installed on the stay that clamps the workpiece that has passed through the forming hole of the specific die and moved to the underside of the specific die.

[0021] According to the transfer device described in (7) above, a stay attached to a reciprocating slide bar is provided with a plurality of transport fingers for clamping a workpiece, and the stay extends toward the underside of a specific die. The stay is also provided with below-die removal fingers for clamping a workpiece that has moved to the underside of the specific die. Therefore, by clamping a workpiece that has passed through the specific die with the below-die removal fingers and driving the slide bar, the workpiece can be removed from the underside of the specific die. According to the transfer device described in (6) above, the slide bar is provided with a stay extending from the slide bar to the underside of the specific die, and the stay is provided with below-die removal fingers, making it possible to remove a workpiece from the underside of the specific die using a small and simple mechanism.

[0022] As described above, according to the transfer device described in (7) above, the workpiece can be removed from the underside of the die, and the device can be made smaller and simpler.

[0023] (8) In the transfer device of the present invention, it is more preferable that the stay has a member fixed to the slide bar and extending from the slide bar toward a position below the specific die.

[0024] According to the transfer device described in (8) above, the stay that extends from the slide bar to the underside of the specific die and on which the below-die removal finger is installed can be configured with a simple structure that includes a member that is fixed to the slide bar and extends from the slide bar toward the underside of the specific die, thereby enabling further miniaturization and simplification of the device.

[0025] According to the present invention, it is possible to provide a press system and a transfer device that can remove a workpiece from below the die and that can achieve a compact and simple device.

[0026] FIG. 1 is an example of a press system according to the present embodiment. FIG. 1 is a perspective view schematically illustrating an enlarged view of a main part of the press system. FIG. 2 is a perspective view schematically illustrating an enlarged view of a main part of the press system including a cross section. FIG. 3 is a cross-sectional view schematically illustrating an enlarged view of a main part of the press system. FIG. 4 is a view of a main part of the press system for explaining the operation of the press system. FIG. 5 is a view of a main part of the press system for explaining the operation of the press system. FIG. 6 is a view of a main part of the press system for explaining the operation of the press system. FIG. 7 is a view of a main part of the press system for explaining the operation of the press system. FIG. 8 is a view of a main part of the press system for explaining the operation of the press system. FIG. 9 is a view of a main part of the press system for explaining the operation of the press system. FIG. 10 is a view of a main part of the press system for explaining the operation of the press system. FIG. 11 is a view of a main part of the press system for explaining the operation of the press system. FIG. 12 is a view of a main part of the press system for explaining the operation of the press system. FIG. 13 is a view of a main part of the press system for explaining the operation of the press system. FIG. 14 is a view of a main part of the press system for explaining the operation of the press system.

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention can be widely applied to a variety of uses, such as a press system including multiple press working sections each having a die and a punch and performing press drawing on a workpiece multiple times, and a transfer device used in the press system to transport the workpiece. In the following explanation, first, a general configuration of the press system according to the embodiment of the present invention will be described, and then, characteristic configurations of the press system and transfer device according to the embodiment of the present invention will be described.

[0028] [1. Overview of the Press System] A press system 1 according to an embodiment of the present invention will be described with reference to Figures 1 to 3. In the following description, the up-down direction, left-right direction, and front-rear direction are defined as indicated by arrows in Figures 1 to 3 and in the drawings described below. The up-down direction is defined based on the vertical direction. The left-right direction is defined as a direction parallel to the direction in which the workpiece W (see Figure 3) is transported in the press system 1. The front-rear direction is defined as a direction perpendicular to both the up-down direction and the left-right direction.

[0029] Referring to FIG. 1 , the press system 1 includes a plurality of press working sections, each having a die 71 and a punch 70, and is configured as a system that performs a plurality of press drawing operations on a workpiece W. The press system 1 is configured as a press system that, for example, performs a plurality of press drawing operations to form a rectangular cylindrical container having a bottom by forming the workpiece W from a flat plate into a rectangular cylindrical shape having a bottom. The press system 1 includes a work supply device 10 and a transfer press device 50. In this embodiment, the work supply device 10 is disposed on the left side, and the transfer press device 50 is disposed on the right side. The work supply device 10 supplies the workpiece W to the transfer press device 50. The transfer press device 50 includes a plurality of press working sections, each having a die 71 and a punch 70. FIGS. 2 and 3 show a press working section provided downstream in the workpiece transport direction among the plurality of press working sections in the transfer press device 50, and a portion nearby. FIG. 3 also shows a schematic cross-sectional view of the workpiece W to be processed in the press working section in the final step among the multiple press working sections, and the punch 70 in the press working section in the final step.

[0030] The work supply device 10 is a device that supplies workpieces W to the transfer press device 50, and is disposed adjacent to the transfer press device 50 on the upstream side of the workpiece transport direction (transport direction of the workpiece W). The transport direction of the workpiece W in the transfer press device 50 is set to the left-right direction. The work supply device 10 includes a frame 12 that stands vertically and is composed of a pair of side walls (13A, 13B) that face each other in the left-right direction. The frame 12 has a structure in which a ram support wall 14, a bolster support wall 16, etc. are disposed between the pair of side walls (13A, 13B). A drive unit 79 that drives a pair of slide bars (78A, 78B) of a transfer device 76, which will be described later, is disposed on the left side of the work supply device 10.

[0031] The ram support wall 14 supports a ram 20 so that it can move up and down, i.e., ascend and descend. The ram 20 receives power from a servo motor (not shown) through a camshaft 22, enabling it to move up and down. The ram 20 also supports a punch (not shown). The left end of the camshaft 22 protrudes outward through the left side wall 13A, one of a pair of side walls (13A, 13B) arranged opposite each other in the left-right direction. The portion protruding outward through the left side wall 13A is connected to the servo motor (not shown) via a pulley 24 and a timing belt (not shown). When the camshaft 22 is driven to rotate by the servo motor (not shown), the ram 20 reciprocates up and down. A flywheel 26 is attached to the left end of the camshaft 22, along with the pulley 24. The pulley 24, timing belt (not shown), and flywheel 26 are all covered by a side cover 28 fixed to the outer surface of the side wall 13A.

[0032] The bolster support wall 16 supports the die holder 30 via the bolster 18. The die holder 30 has a two-stage structure consisting of an upper stage and a lower stage. The height position of the upper surface of the lower stage of the die holder 30 corresponds to the height position of the upper surface of the die 71 supported by the die holder 72 in the transfer press device 50. The upper stage of the die holder 30 is disposed above the upper surface of the lower stage with a gap therebetween. A die (not shown) is held in the upper stage of the die holder 30.

[0033] In the work supply device 10, the ram 20 is moved downward to punch out the metal sheet with a punch and die (not shown) supported by the ram 20, thereby forming a flat workpiece W. The flat workpiece W formed by the work supply device 10 is supplied to the transfer press device 50.

[0034] 1, the transfer press device 50 is disposed adjacent to the downstream side in the work transport direction of the work supply device 10. The work W in a flat plate state formed by the work supply device 10 is transported to the transfer press device 50, and the transfer press device 50 applies press drawing to the work W multiple times.

[0035] The transfer press device 50 includes a frame 52 that is configured with a pair of vertically standing side walls (53A, 53B) that face each other in the left-right direction. The frame 52 has a structure in which a ram support wall, a bolster support wall 56, and the like (not shown) are placed between the pair of side walls (53A, 53B).

[0036] A ram support wall (not shown) supports the ram 60 so that it can move up and down, i.e., can move up and down. The ram 60 receives power from a servo motor (not shown) through a camshaft 62, allowing it to move up and down. The ram 60 also supports a plurality of punches 70 arranged in the left-right direction (i.e., the direction in which the workpiece W is transported). A camshaft 62 extends between a pair of side walls (53A, 53B) above the ram support wall (not shown). The ram 60 engages with a cam 61 of the camshaft 62.

[0037] The right end of the camshaft 62 penetrates the right side wall 53B of the pair of side walls (53A, 53B) that are arranged opposite each other in the left-right direction, and protrudes outward. The portion that protrudes outward through the right side wall 53B is connected to the servo motor (not shown) via a pulley 64 and a timing belt (not shown).

[0038] When the camshaft 62 is driven to rotate by a servo motor (not shown), the ram 60 moves up and down. A pulley 64 and a flywheel 66 are attached to the right end of the camshaft 62. The pulley 64, a timing belt (not shown), and various other components including the flywheel 66 are covered by a side cover 68 fixed to the outer surface of the side wall 53B.

[0039] The bolster support wall 56 spans between the lower end portions of the pair of side walls (53A, 53B), and a bolster 58 is fixed to the upper surface of the bolster support wall 56. The transfer press apparatus 50 also includes a plate-shaped lower die set 73 that is disposed on the upper surface of the bolster 58. A plurality of press working units are mounted on the lower die set 73, each of which has a die 71 and a die holder 72 that supports the die 71. More specifically, the die holders 72 of the plurality of press working units are mounted on the lower die set 73. The transfer press apparatus 50 also has the same number of dies 71 and punches 70, and a pair of punches 70 arranged vertically, and the dies 71 and die holders 72 that support the dies 71 constitute one of the plurality of press working units.

[0040] 1 to 3 , the transfer press device 50 includes multiple press working sections, each having a die 71 and a punch 70, and is configured as an apparatus for performing press drawing on a workpiece W multiple times. The multiple press working sections, each including a die 71 and a punch 70, are arranged side by side in the left-right direction, which is the workpiece transport direction, and multiple pairs of dies 71 and punches 70 are arranged at a constant pitch in the left-right direction. The die 71 of each press working section is fixed to the upper surface of a die holder 72. The die 71 has a forming hole 74 that is elongated in a plan view viewed from above. The press drawing is performed by the punch 70 pushing the workpiece W through the elongated forming hole 74 of the die 71. By pushing the workpiece W through the elongated forming hole 74 of the die 71, the workpiece W is formed into a cylindrical shape having an elongated cross-sectional shape. In addition, a knockout pin 75 is arranged below the forming hole 74 of the die 71. When the punch 70 presses the workpiece W into the forming hole 74 of the die 71 to form it, the knockout pin 75 presses the bottom surface of the workpiece W upward to restrict downward bulging of the workpiece W. In addition, the knockout pin 75 can push the workpiece W upward from the forming hole 74 of the die 71 when the punch 70 rises or after the punch 70 has come out of the workpiece W.

[0041] The transfer press device 50 also includes a transfer device 76 that transports the workpiece W processed in one of the multiple press working units toward the press working unit for the next process. The workpiece W is transported downstream in the workpiece transport direction by the transfer device 76. The workpiece W is transported downstream in the workpiece transport direction by the transfer device 76, and is subjected to press drawing in each of multiple pairs of dies 71 and punches 70 lined up in the left-right direction.

[0042] 1 to 3, the transfer device 76 provided in the transfer press device 50 of the press system 1 is configured as a transfer device according to an embodiment of the present invention. That is, the transfer device 76 is used in the press system 1 that has a plurality of press working sections, each having a die 71 and a punch 70, and performs press drawing on the workpiece W multiple times, and is configured as a device that transports the workpiece W that has been processed in one of the plurality of press working sections to the press working section for the next process.

[0043] The transfer device 76 includes a plurality of transport fingers 77, a pair of slide bars (78A, 78B) on which the plurality of transport fingers 77 are mounted, and a drive unit 79 that reciprocates the slide bars (78A, 78B). The transfer device 76 also includes a stay 80 and a below-die removal finger 81 that constitute a mechanism for removing the workpiece W from below a specific die 71A, which is the die 71 of one of the press working units among the plurality of press working units. The stay 80 is provided to extend from the end of the slide bars (78A, 78B), and the below-die removal finger 81 is attached to the stay 80.

[0044] In this embodiment, the stays 80 are arranged to extend from the ends of the slide bars (78A, 78B), but this is not necessarily the case. The slide bars (78A, 78B) may be arranged to extend even longer, and the stays 80 may be arranged to extend from the middle of the longer slide bars (78A, 78B). Also, in this embodiment, the specific die 71A is configured as the die 71 of the press working unit for the final process among the multiple press working units. Note that the specific die 71A does not have to be configured as the die 71 of the press working unit for the final process. The specific die 71A may be configured as the die of the press working unit for a process other than the final process among the multiple press working units.

[0045] 1 to 3 , a pair of slide bars (78A, 78B) of the transfer device 76 are provided and arranged on a plurality of dies 71 lined up along the workpiece W transport direction (workpiece transport direction). The pair of slide bars (78A, 78B) are arranged to be slidable on the dies 71 along the workpiece W transport direction, and are provided as shaft-shaped members extending along the workpiece W transport direction (i.e., the left-right direction), and a plurality of transport fingers 77 are installed on the pair of slide bars (78A, 78B). The pair of slide bars (78A, 78B) are arranged parallel to each other with a certain distance between them in the front-rear direction. Note that in FIGS. 2 and 3 , only a portion of the slide bars (78A, 78B) of the transfer device 76 is illustrated, and the left portions of the slide bars (78A, 78B) are not illustrated. In this embodiment, the pair of slide bars (78A, 78B) are arranged on a plurality of dies 71 lined up along the workpiece transport direction, but this does not have to be the case. The pair of slide bars (78A, 78B) may be arranged on both sides in the front-to-rear direction of the multiple dies 71 lined up along the work transport direction (i.e., on both sides in the direction perpendicular to the work transport direction).

[0046] Referring to FIG. 1 , the drive unit 79 is provided as a mechanism that reciprocates the pair of slide bars (78A, 78B) along the workpiece W transport direction (workpiece transport direction). The drive unit 79 is configured to include a ball screw mechanism or a cylinder mechanism that is connected to one end of each of the pair of slide bars (78A, 78B) in the workpiece transport direction. In this embodiment, the ball screw mechanism or cylinder mechanism of the drive unit 79 is connected to the left end of each of the pair of slide bars (78A, 78B). By operating the ball screw mechanism or cylinder mechanism of the drive unit 79, the pair of slide bars (78A, 78B) are driven to reciprocate along the workpiece transport direction.

[0047] 1 to 3 , the multiple transport fingers 77 are provided to clamp the workpiece W from both sides in a direction perpendicular to the transport direction of the workpiece W, and are provided as a mechanism for clamping and transporting the workpiece W along the transport direction. In this embodiment, each of the multiple transport fingers 77 is provided to clamp the workpiece W from both sides in the front-to-rear direction, which is perpendicular to the left-to-right direction, which is the transport direction of the workpiece W. The multiple transport fingers 77 are also provided on a pair of slide bars (78A, 78B). The multiple transport fingers 77 are provided on the pair of slide bars (78A, 78B) so as to be positioned corresponding to the multiple press working portions, respectively. Therefore, when the pair of slide bars (78A, 78B) are driven by the drive unit 79 to move along the workpiece transport direction, the multiple transport fingers 77 also move along the workpiece transport direction together with the pair of slide bars (78A, 78B). This allows the workpiece W clamped by the transport fingers 77 to be transported downstream in the workpiece transport direction.

[0048] Each of the multiple transport fingers 77 includes a pair of finger main bodies 82 and a pair of air cylinders 83 as drive sources for driving each of the pair of finger main bodies 82 in the front-rear direction. The pair of finger main bodies 82 of the transport fingers 77 are provided as parts that abut against the workpiece W from both sides in the front-rear direction and directly grip the workpiece W from both sides in the front-rear direction. Each of the pair of finger main bodies 82 is attached to the tip end of each of the rods of a pair of air cylinders 83. The cylinder main bodies of each of the pair of air cylinders 83 are fixedly attached to each of a pair of slide bars (78A, 78B). In each transport finger 77, the pair of finger main bodies 82 are configured to be able to open and close by operation of the pair of air cylinders 83. One air cylinder 83 of the pair of air cylinders 83 and the other air cylinder 83 of the pair of air cylinders 83 are displaced symmetrically in the front-rear direction. When the pair of finger bodies 82 are operated from an open state to a closed state, the pair of air cylinders 83 drive the pair of finger bodies 82 to displace them in directions toward each other. On the other hand, when the pair of finger bodies 82 are operated from a closed state to an open state, the pair of air cylinders 83 drive the pair of finger bodies 82 to displace them in directions away from each other. In this way, the transport fingers 77 are configured to be able to release or clamp the workpiece W by opening and closing the finger bodies 82.

[0049] The spacing between adjacent transport fingers 77 in the workpiece transport direction (i.e., the left-right direction) is the same constant pitch as the spacing between adjacent punches 70 and dies 71 in the left-right direction. The drive unit 79 repeatedly moves the pair of slide bars (78A, 78B) back and forth in the left-right direction at a constant pitch while maintaining a horizontal position, in synchronization with the raising and lowering movement of the ram 60. The pair of air cylinders 83 of each transport finger 77 repeatedly open and close the pair of finger main bodies 82 so that the workpiece W is transported by the left-right reciprocating movement of the pair of slide bars (78A, 78B). In this way, the workpiece W is transported by the transfer device 76 from the upstream side (i.e., the left side) in the workpiece transport direction to the downstream side (i.e., the right side) in the workpiece transport direction, and is subjected to press drawing in sequence by the dies 71 and punches 70 in each of the multiple press working units. This allows the workpiece W to be subjected to press drawing multiple times.

[0050] When the press system 1 performs multiple drawing processes on the workpiece W, a number of dies 71 and punches 70 corresponding to the number of drawing processes to be performed are used. Note that the press system 1 illustrated in FIG. 1 exemplifies a configuration in which eight pairs of dies 71 and punches 70 are provided. When eight drawing processes are performed on the workpiece W, eight pairs of dies 71 and punches 70 are used. For example, when five drawing processes are performed on the workpiece W, only five pairs of dies 71 and punches 70 are used. That is, in this case, only five pairs of dies 71 and punches 70 out of the eight pairs of dies 71 and punches 70 are attached and used in the press system 1, and the other three pairs of dies 71 and punches 70 are not attached to the press system 1. Note that, in the press system 1, where dies 71 cannot be attached, for example, a block-shaped member without a forming hole is attached.

[0051] Furthermore, in the transfer press device 50, a workpiece unloading area is provided downstream in the workpiece transport direction of a plurality of press working sections each having a die 71 and a punch 70, for transporting and unloading the workpiece W after multiple press drawing operations. The workpiece W transported and unloaded through the workpiece unloading area is unloaded, for example, to an apparatus that performs a process subsequent to the process performed by the press system 1. With reference to FIGS. 1 and 2 , the workpiece unloading area is provided with a plate 84 disposed on the upper surface of the bolster support wall 56, a pair of lower slide bars (85A, 85B) disposed on the plate 84, and a workpiece holding mechanism 86 disposed above the plate 84 and the pair of lower slide bars (85A, 85B).

[0052] The plate 84 is disposed adjacent to the lower die set 73 on the downstream side in the workpiece conveying direction. After multiple press drawing processes have been completed, the workpiece W is conveyed along the plate 84 and carried out.

[0053] 1 and 2 , a pair of lower slide bars (85A, 85B) are slidably disposed on a plate 84 along the workpiece transport direction and are provided as shaft-shaped members extending along the workpiece transport direction (i.e., the left-right direction). The pair of lower slide bars (85A, 85B) are disposed parallel to each other at a fixed distance in the front-rear direction. Each of the pair of lower slide bars (85A, 85B) is connected at its upstream end in the workpiece transport direction to each of the pair of slide bars (78A, 78B) via a connecting member 87 extending vertically. The upstream end of the lower slide bar 85A in the workpiece transport direction is connected to the downstream end of the slide bar 78A in the workpiece transport direction via the connecting member 87. The upstream end of the lower slide bar 85B in the workpiece transport direction is connected to the downstream end of the slide bar 78B in the workpiece transport direction via the connecting member 87. Furthermore, the connecting members 87 extend downward from the ends of the slide bars (78A, 78B) and are connected to the ends of the lower slide bars (85A, 85B). Therefore, the pair of lower slide bars (85A, 85B) are disposed below the pair of slide bars (78A, 78B). Because the pair of lower slide bars (85A, 85B) are connected to the pair of slide bars (78A, 78B), when the pair of slide bars (78A, 78B) are driven to reciprocate along the work transport direction, the pair of lower slide bars (85A, 85B) are also driven to reciprocate along the work transport direction together with the pair of slide bars (78A, 78B).

[0054] Referring to FIG. 2 , a plurality of transport fingers 77 are provided on the pair of lower slide bars (85A, 85B). The transport fingers 77 provided on the pair of lower slide bars (85A, 85B) are configured similarly to the transport fingers 77 provided on the pair of slide bars (78A, 78B). The plurality of transport fingers 77 provided on the pair of lower slide bars (85A, 85B) are configured to clamp the workpiece W from both sides in the front-to-rear direction perpendicular to the workpiece transport direction, and are provided as a mechanism for clamping the workpiece W and transporting it along the transport direction. When the pair of slide bars (78A, 78B) are driven and moved by the drive unit 79, the pair of lower slide bars (85A, 85B) also move together with the pair of slide bars (78A, 78B). The plurality of transport fingers 77 provided on the pair of lower slide bars (85A, 85B) also move along the workpiece transport direction together with the pair of lower slide bars (85A, 85B). As a result, the workpiece W held by the transport fingers 77 installed on the pair of lower slide bars (85A, 85B) is transported downstream in the workpiece transport direction in the workpiece unloading area.

[0055] 1 and 2, the workpiece holding mechanism 86 is provided as a mechanism for holding down and supporting the workpiece W from above when the workpiece W is not clamped by the transport fingers 77 installed on the pair of lower slide bars (85A, 85B). The workpiece holding mechanism 86 has an air cylinder 89 installed so as to extend downward from a cylinder support wall 88 installed adjacent to the ram 60 in the upper region of the transfer press device 50, a presser plate 90 attached to the lower end of the air cylinder 89, and a plurality of workpiece pressers 91 installed below the presser plate 90.

[0056] The air cylinder 89 is configured to reciprocate the pressure plate 90 in the vertical direction. A plurality of workpiece holders 91 are connected to the pressure plate 90 via arms 91a extending downward from the pressure plate 90 and are installed below the pressure plate 90. Each of the plurality of workpiece holders 91 is configured to abut against the upper end of the workpiece W and press down on the workpiece W from above to support the workpiece W. When the workpiece W changes from being clamped by the transport fingers (85A, 85B) to being no longer clamped, the air cylinder 89 is activated, the pressure plate 90 is lowered, and the plurality of workpiece holders 91 are also lowered along with the pressure plate 90. Each of the lowered plurality of workpiece holders 91 then abuts against the upper end of the workpiece W to press down on the workpiece W, thereby supporting the workpiece W. Furthermore, when the workpiece W changes from being no longer clamped by the transport fingers (85A, 85B) to being clamped, the air cylinder 89 is activated, the pressure plate 90 is raised, and the plurality of workpiece holders 91 are also raised along with the pressure plate 90. This releases the support of the workpiece W by the workpiece holding mechanism 86. In this way, when the workpiece W is not clamped by the transport fingers 77, the workpiece W is supported by the workpiece holding mechanism 86, and the workpiece W is prevented from tipping over.

[0057] [2. Characteristic Configurations of the Press System and Transfer Device] Next, a description will be given of the characteristic configurations of the press system 1 of this embodiment and the transfer device 76 of this embodiment used in the press system 1. Fig. 4 is an enlarged cross-sectional view schematically showing a main part of the press system 1, taken along a cross section perpendicular to the left-right direction. Fig. 4 is a cross-sectional view taken at a position corresponding to a specific die 71A configured as the die 71 of the press working unit in the final process among multiple press working units.

[0058] 1 to 4, the transfer device 76 of the press system 1 is configured to be able to remove a workpiece W from below a specific die 71A configured as the die 71 of the press working section for the final process among a plurality of press working sections. The transfer device 76 includes a stay 80 and an under-die removal finger 81 to form a mechanism for removing the workpiece W from below the specific die 71A.

[0059] 1 to 4, the stays 80 are provided as members extending from the slide bars (78A, 78B) toward the underside of the specific die 71A. In the transfer device 76, the stays 80 are provided in pairs, and each of the pair of stays 80 is provided so as to extend from the pair of slide bars (78A, 78B) toward the underside of the specific die 71A. That is, one of the pair of stays 80 is provided so as to extend from the slide bar 78A toward the underside of the specific die 71A. The other of the pair of stays 80 is provided so as to extend from the slide bar 78B toward the underside of the specific die 71A.

[0060] The stay 80 is fixed to the slide bars (78A, 78B) and includes a member extending from the slide bars (78A, 78B) downward toward the specific die 71A. More specifically, in this embodiment, the stay 80 is configured with an upper and lower member 80a and a horizontal member 80b. The upper and lower member 80a is a rectangular column-shaped member fixed to the slide bars (78A, 78B) and extending downward from the slide bars (78A, 78B) in the vertical direction. The upper and lower member 80a of one of the pair of stays 80 is fixedly attached to the slide bar 78A, and the upper and lower member 80a of the other of the pair of stays 80 is fixedly attached to the slide bar 78B. The downstream end of the slide bars (78A, 78B) in the workpiece transport direction is positioned to protrude downstream of the specific die 71A in the workpiece transport direction. The upper and lower members 80a of the stay 80 are fixed at their upper end portions to the downstream ends of the slide bars (78A, 78B) in the workpiece transport direction. Furthermore, the upper and lower members 80a are fixed to the slide bars (78A, 78B) at the inner side surfaces of the pair of slide bars (78A, 78B) in the front-to-rear direction. The upper and lower members 80a are provided so as to extend downward from the ends of the slide bars (78A, 78B) at a position downstream of the specific die 71A in the workpiece transport direction.

[0061] The horizontal member 80b of the stay 80 is fixed to the upper and lower members 80a and is provided as a long, thin plate-like member extending horizontally from the upper and lower members 80a toward below the specific die 71A. That is, in each of the pair of stays 80, the horizontal member 80b is fixed to the upper and lower members 80a and extends horizontally from the upper and lower members 80a toward below the specific die 71A. The horizontal member 80b is also fixed to the upper and lower members 80a at the lower end of the upper and lower members 80a. The horizontal member 80b extends from the lower end of the upper and lower members 80a toward the upstream side in the workpiece transport direction, thereby extending toward below the specific die 71. A die lower removal finger 81 is provided at the tip end of the horizontal member 80b extending from the upper and lower members 80a toward below the specific die 71.

[0062] 2 to 4 , the below-die removal fingers 81 are installed on the stay 80 and function as a mechanism for clamping the workpiece W that has passed through the forming holes 74 of the specific die 71A and moved to the lower side of the specific die 71A. In this embodiment, the below-die removal fingers 81 are configured to clamp the workpiece W from both sides in the front-to-rear direction perpendicular to the workpiece transport direction, and are configured as a mechanism for clamping the workpiece W and removing the workpiece W from the lower side of the specific die 71A downstream in the workpiece transport direction. The below-die removal fingers 81 are installed on the horizontal members 80b of the pair of stays 80, which are respectively fixed to the pair of slide bars (78A, 78B). The below-die removal fingers 81 are installed on the horizontal members 80b of the stay 80 so as to be positionable below the specific die 71A at positions corresponding to the forming holes 74 of the specific die 71A. When the pair of slide bars (78A, 78B) are driven and moved by the drive unit 79, the pair of stays 80 also move together with the pair of slide bars (78A, 78B). Then, the below-die removal fingers 81 installed on the pair of stays 80 also move downstream in the work transport direction together with the pair of stays 80. As a result, the work W clamped by the below-die removal fingers 81 below the specific die 71A is removed from below the specific die 71A downstream in the work transport direction.

[0063] 2 to 4 , the below-die extraction fingers 81 include a pair of finger main bodies 92 and a pair of air cylinders 93 as drive sources for driving each of the pair of finger main bodies 92 in the front-rear direction. The pair of finger main bodies 92 of the below-die extraction fingers 81 are provided as portions that contact the workpiece W from both sides in the front-rear direction and directly grip the workpiece W from both sides in the front-rear direction. Each of the pair of finger main bodies 92 is attached to the tip of a respective rod 93 a of a pair of air cylinders 93. The respective cylinder main bodies 93 b of the pair of air cylinders 93 are fixed to each of the horizontal members 80 b of the pair of stays 80. The cylinder main bodies 93 b of the air cylinders 93 are fixed to the upper surface of the horizontal member 80 b. In the below-die extraction fingers 81, the pair of finger main bodies 92 are configured to be openable and closable by operation of the pair of air cylinders 93. One air cylinder 93 and the other air cylinder 93 of the pair of air cylinders 93 are displaced symmetrically in the front-to-rear direction. When operating the pair of finger main bodies 92 from an open state to a closed state, the pair of air cylinders 93 drive the pair of finger main bodies 92 to displace them in directions toward each other. On the other hand, when operating the pair of finger main bodies 92 from a closed state to an open state, the pair of air cylinders 93 drive the pair of finger main bodies 92 to displace them in directions away from each other. In this way, the below-die removal fingers 81 are configured to be able to release or clamp the workpiece W by opening and closing the finger main bodies 92.

[0064] 2 to 4 , the press working unit having the specific die 71A has a specific die holder 72A that supports the specific die 71A as the die holder 72 that supports the die 71. The specific die holder 72A has a through hole 94 through which the workpiece W passes after passing through the forming hole 74 of the specific die 71A, and an opening 95 into which the horizontal member 80b of the stay 80 is inserted. The through hole 94 is provided in the upper end wall portion of the specific die holder 72A that supports the specific die 71A, as a hole that penetrates vertically at a position corresponding to the forming hole 74. The through hole 94 allows the workpiece W that passes through the forming hole 74 of the specific die 71A toward the lower side of the specific die 71A to pass through, and is also provided so that a knockout pin 75 can be inserted from below.

[0065] The opening 95 of the specific die holder 72A is open toward the downstream side in the workpiece transport direction, and is provided so as to open the area below the specific die 71A toward the downstream side in the workpiece transport direction. The opening 95 is provided so as to open the area below the specific die 71A toward the downstream side in the workpiece transport direction, allowing the horizontal member 80b of the stay 80 extending below the specific die 71A to be inserted therein. The opening 95 is also configured so that the horizontal member 80b of the stay 80 and the die lower removal finger 81 attached to the horizontal member 80b can be inserted therein. In this embodiment, the specific die holder 72A provided with the opening 95 is formed in a frame-like shape that supports the specific die 71A. Furthermore, in this embodiment, the frame-shaped specific die holder 72A is formed in a gate-like shape. That is, the specific die holder 72A does not have walls separating the left and right sides and a wall separating the lower part, and is formed in a gate-like shape that is open on both the left and right sides and the lower part.

[0066] 1 to 4 , in the lower die set 73 on which the die holders 72 of the multiple press working units are mounted, a step 73a is formed so that the vertical height of the portion on which a specific die holder 72A is mounted is lower than the vertical height of the portion on which the die holder 72 of the press working unit for the process before the press working unit having the specific die holder 72A is mounted. Therefore, in this embodiment, the lower die set 73 is configured so that the vertical thickness of the portion on which the specific die holder 72A is mounted is thinner than the thickness of the portion on which the die holder 72 of the press working unit for the process before the press working unit having the specific die holder 72A is mounted. The height dimension of the specific die holder 72A is set so that the height position of the upper end surface of the specific die holder 72A coincides with the height position of the die holder 72 of the press working unit for the process before the press working unit having the specific die holder 72A. Therefore, in this embodiment, although the height positions of the upper end surfaces of a specific die holder 72A and die holders 72 other than the specific die holder 72A are the same, the height dimension of the specific die holder 72A is set larger than the height dimension of die holders 72 other than the specific die holder 72A.

[0067] [3. Operation of the Press System and Transfer Device] Next, the operation of the press system 1 and transfer device 76 of this embodiment when the workpiece W is removed from below the specific die 71A will be described. Figures 5 to 7 are diagrams for explaining the operation of the press system 1 and the transfer device 76, and are cross-sectional views of the main parts of the press system 1, showing the state after press processing with the specific die 71A. Note that Figure 5 is a cross-sectional view of the main parts of the press system 1 taken along the left-right direction, Figure 6 is a cross-sectional view of the main parts of the press system 1 taken along the line A-A in Figure 5, and Figure 7 is a cross-sectional view of the main parts of the press system 1 taken along the line B-B in Figure 6. Furthermore, Figures 5 to 7 show cross-sections of the main parts of the press system 1, including the specific die 71A and the surrounding area.

[0068] 5 to 7, when the workpiece W is subjected to press drawing in the press working section having the specific die 71A, the horizontal member 80b of the stay 80 of the transfer device 76 is inserted into the opening 95 of the specific die holder 72A, and the below-die removal finger 81 attached to the horizontal member 80b is also inserted into the opening 95 and positioned below the specific die 71A. Then, when the workpiece W is subjected to press drawing in the press working section having the specific die 71A, the workpiece W passes through the forming hole 74 of the specific die 71A and moves to the below of the specific die 71A.

[0069] When the workpiece W passes through the forming hole 74 of the specific die 71A and moves to the lower side of the specific die 71A, the punch 70 is inserted inside the workpiece W, and the lower end of the workpiece W is supported by the knockout pin 75. Note that when the press drawing of the workpiece W is performed in the press processing unit having the specific die 71A and the workpiece W moves to the lower side of the specific die 71A, the knockout pin 75 stops at a position where the upper end of the knockout pin 75 is flush with the upper surface of the lower die set 73. Therefore, the lower end of the workpiece W is supported by the knockout pin 75 at the same height as the upper surface of the lower die set 73. Also, when the workpiece W moves to the lower side of the specific die 71A, the pair of finger main bodies 92 of the lower die removal fingers 81 inserted into the opening 95 of the specific die holder 72A and arranged below the specific die 71A are in an open state. Therefore, the workpiece W that has moved to the lower side of the specific die 71A is separated from the pair of finger main bodies 92 and is not clamped by the under-die removal fingers 81.

[0070] Once the workpiece W has moved below the specific die 71A, the workpiece W is then clamped by the below-die removal fingers 81. Furthermore, once the workpiece W has moved below the specific die 71A, the stripper 69 provided inside the specific die holder 72A protrudes in the front-to-rear direction to a position where it can vertically abut against the upper end of the workpiece W with the punch 70 inserted therein (see FIG. 10 ). The tip of the stripper 69 abuts against the upper end of the workpiece W from above, thereby restricting the lift of the workpiece W and releasing the workpiece W from the punch 70 when the punch 70 is pulled upward from the workpiece W. FIGS. 8 to 10 are cross-sectional views of essential parts of the press system 1 for explaining the operation of the press system 1 and the transfer device 76, and are views showing the state in which the below-die removal fingers 81 clamp the workpiece W after press processing with the specific die 71A. 8 is a cross-sectional view of the main parts of the press system 1 taken along the left-right direction, Fig. 9 is a cross-sectional view of the main parts of the press system 1 taken along the line CC in Fig. 8, and Fig. 10 is a cross-sectional view of the main parts of the press system 1 taken along the line DD in Fig. 9. Also, Figs. 8 to 10 show cross-sections of the main parts of the press system 1, i.e., cross-sections of a specific die 71A and its surrounding area.

[0071] 8 to 10 , once the workpiece W has moved below the specific die 71A, the workpiece W is then clamped by the below-die extraction fingers 81 while the workpiece W remains supported by the punch 70 and the knockout pin 75. Furthermore, the stripper 69 protrudes in the front-to-rear direction toward the punch 70 to a position where it can abut against the upper end of the workpiece W from above in the vertical direction. When the workpiece W is clamped by the below-die extraction fingers 81, the pair of air cylinders 93 of the below-die extraction fingers 81 are actuated to drive the pair of finger bodies 92 toward each other. This causes the pair of finger bodies 92 to move from an open state to a closed state and abut against the workpiece W from both sides in the front-to-rear direction. The pair of finger bodies 92 abut against the workpiece W from both sides in the front-to-rear direction, resulting in the workpiece W being clamped by the below-die extraction fingers 81. When the workpiece W is clamped between the lower die removal fingers 81 and the tip of the stripper 69 is positioned to abut against the upper end of the workpiece W from above, the punch 70 is pulled upward from the specific die 71A. When the punch 70 is pulled upward, the tip of the stripper 69 abuts against the upper end of the workpiece W, causing the punch 70 to be pulled out from the workpiece W and the workpiece W to be released from the punch 70. Note that when the punch 70 is pulled out from the workpiece W and the workpiece W is released from the punch 70, both sides of the workpiece W in the front-to-rear direction are clamped between the pair of finger main bodies 92, and the lower end of the workpiece W is supported by the upper end of the knockout pin 75 located at the same height as the upper surface of the lower die set 73.

[0072] Once the workpiece W is released from the punch 70 and clamped by the under-die removal fingers 81 below the specific die 71A, the workpiece W is then removed from below the specific die 71A downstream in the workpiece transport direction. FIG. 11 is a diagram for explaining the operation of the press system 1 and the transfer device 76, showing a cross-sectional view of the main parts of the press system 1 and showing the state in which the workpiece W has been removed from below the specific die 71A. Note that FIG. 11 is a cross-sectional view of the main parts of the press system 1 taken along the left-right direction. FIG. 12 is a cross-sectional view of the main parts of the press system 1 taken along the line E-E in FIG. 11 . FIG. 13 is a cross-sectional view of the main parts of the press system 1 taken along the line F-F in FIG. 12 . Also, FIGS. 11 to 13 show cross-sections of the main parts of the press system 1, including the specific die 71A and the surrounding area.

[0073] 11 to 13 , once the workpiece W is clamped by the below-die removal fingers 81 below the specific die 71A, the workpiece W is then removed from below the specific die 71A downstream in the workpiece transport direction. At this time, with the below-die removal fingers 81 clamping the workpiece W below the specific die 71A, the pair of slide bars (78A, 78B) are driven by the drive unit 79 to move downstream in the workpiece transport direction. As the pair of slide bars (78A, 78B) move downstream in the workpiece transport direction, the pair of stays 80 also move downstream in the workpiece transport direction together with the pair of slide bars (78A, 78B). The below-die removal fingers 81, which are installed on the pair of stays 80 and clamp the workpiece W, also move downstream in the workpiece transport direction together with the pair of stays 80. As a result, the workpiece W clamped by the below-die removal fingers 81 below the specific die 71A is removed downstream in the workpiece transport direction from below the specific die 71A. When the workpiece W clamped by the below-die removal fingers 81 below the specific die 71A is removed downstream in the workpiece transport direction, the workpiece W is transported downstream in the workpiece transport direction with the lower end of the workpiece W in sliding contact with the upper surface of the lower die set 73 and the upper end of the knockout pin 75 positioned at the same height as the upper surface of the lower die set 73.

[0074] When the workpiece W is removed from below a specific die 71A toward the downstream side in the workpiece transport direction, the air cylinder 89 of the workpiece holding mechanism 86 is activated, causing the workpiece holder 91 to descend and hold down the workpiece W, so that the workpiece W is supported by the workpiece holding mechanism 86. Once the workpiece W is supported by the workpiece holding mechanism 86, the pair of air cylinders 93 of the below-die removal fingers 81 are activated, driving the pair of finger main bodies 92 in directions separating them from each other. This causes the pair of finger main bodies 92 to shift from a closed state to an open state, releasing the clamping of the workpiece W. Once the clamping of the workpiece W is released, the pair of slide bars (78A, 78B) are driven by the drive unit 79 to move upstream in the workpiece transport direction. When the pair of slide bars (78A, 78B) move upstream in the workpiece transport direction, the pair of stays 80 also move upstream in the workpiece transport direction together with the pair of slide bars (78A, 78B). Then, the lower die removal fingers 81 installed on the pair of stays 80 also move upstream in the workpiece transport direction together with the pair of stays 80. As a result, the lower die removal fingers 81 together with the horizontal members 80b of the stays 80 are inserted into the openings 95 of the specific die holder 72A and placed below the specific die 71A. Once the lower die removal fingers 81 are placed below the specific die 71A, the press drawing of the workpiece W is again performed in the press working section having the specific die 71A.

[0075] [4. Effects of the Present Embodiment] According to the press system 1 and transfer device 76 of the present embodiment, a stay 80 provided on a reciprocatingly driven slide bar (78A, 78B) having a plurality of transport fingers 77 for clamping a workpiece W thereon is extended toward the underside of the specific die 71A. The stay 80 is provided with below-die removal fingers 81 for clamping the workpiece W that has moved to the underside of the specific die 71A. Therefore, by clamping the workpiece W that has passed through the specific die 71A with the below-die removal fingers 81 and driving the slide bar (78A, 78B), the workpiece W can be removed from the underside of the specific die 71A. Furthermore, according to the press system 1 and transfer device 76 of this embodiment, a stay 80 is provided on the slide bar (78A, 78B) that extends from the slide bar (78A, 78B) to the underside of a specific die 71A, and a die-under removal finger 81 is installed on the stay 80, thereby enabling the workpiece W to be removed from the underside of the specific die 71A using a small and simple mechanism.

[0076] As described above, according to the press system 1 and transfer device 76 of this embodiment, the workpiece W can be removed from below the die 71A, and the device can be made smaller and simpler.

[0077] Furthermore, according to the press system 1 and transfer device 76 of this embodiment, the stay 80, which extends from the slide bars (78A, 78B) to the underside of the specific die 71A and on which the die lower removal finger 81 is installed, can be configured with a simple structure that includes members (upper and lower members 80a and 80a) fixed to the slide bars (78A, 78B) and extending from the slide bars (78A, 78B) toward the underside of the specific die 71A. This allows for further miniaturization and simplification of the device.

[0078] Furthermore, according to the press system 1 of this embodiment, an opening 95 for inserting the stay 80 is provided in the specific die holder 72A that supports the specific die 71A from which the workpiece W is removed from below, so that the stay 80 can be easily inserted below the specific die 71A.

[0079] Furthermore, according to the press system 1 of this embodiment, the specific die holder 72A is formed in a frame shape that supports the specific die 71A, so that it is possible to form a wide opening 95 for inserting the stay 80. Furthermore, because the specific die holder 72A has a frame shape, it can be structured to have legs on both sides of the opening 95, and even if the opening 95 is provided in the specific die holder 72A, it is possible to stably support the specific die 71A.

[0080] Furthermore, according to the press system 1 of this embodiment, the height of the upper end surface of the specific die holder 72A and the die holder 72 of the preceding process are the same, and a step 73a that lowers the height of the portion of the lower die set 73 on which the specific die holder 72A is placed is provided. Therefore, a wide space for inserting the stay 80 can be formed vertically in the specific die holder 72A that supports the specific die 71A from which the workpiece W is removed from below. This allows the stay 80 to be easily inserted from below the specific die 71A.

[0081] [5. Modifications] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. For example, the following modifications may be made.

[0082] (1) In the above embodiment, the height of the upper end surface of the specific die holder 72A and the die holder 72 of the preceding process are the same, and a step 73a that lowers the height of the portion of the lower die set 73 on which the specific die holder 72A is placed is provided. However, this is not necessarily the case. Even if the step 73a is not provided in the lower die set 73, a modified press system may be implemented in which the specific die holder 72A has a wide space formed in both the vertical direction for inserting the stay 80, so that the stay 80 can be easily inserted from below the specific die 71A.

[0083] In the press system according to this modification, a lower die set 73 on which a plurality of press working units, each having a die 71 and a die holder 72 supporting the die 71, is mounted is formed as a flat plate without a step 73a. The die holders 72 of the plurality of press working units are mounted on the lower die set 73. A specific die holder 72A is positioned so that the height of its upper end surface coincides with the height of the die holder 72 of the press working unit in the process preceding the press working unit having the specific die holder 72A. Furthermore, the height of the die holder 72 of the press working unit in the process preceding the press working unit having the specific die holder 72A is set to match the height of the specific die holder 72A. According to this modification, the heights of the upper end surfaces of the specific die holder 72A and the die holder 72 of the preceding process coincide with each other, and the height of the die holder 72 of the preceding process is set to match the height of the specific die holder 72A. Therefore, the die holder 72 for the front process and the specific die holder 72A can be manufactured with the same common external shape. Furthermore, by appropriately increasing the height dimensions of the die holder 72 for the front process and the specific die holder 72A, a wide vertical space for inserting the stay 80 can be formed in the specific die holder 72A, and the stay 80 can be easily inserted from below the specific die 71A. Furthermore, by reducing the thickness of the wall portion on the upper end side of the specific die holder 72A and increasing the height of the space inside the specific die holder 72A, a wide vertical space for inserting the stay 80 can be formed in the specific die holder 72A, and the stay 80 can be easily inserted from below the specific die 71A.

[0084] (2) In the above-described embodiment, the specific die holder 72A supporting the specific die 71A is formed in a gate-like shape. However, this is not necessarily the case. The shape of the specific die holder supporting the specific die 71A may be modified to various shapes different from the shape of the specific die holder 72A. For example, the shapes of the specific die holders (72B to 72E) according to modified examples shown in FIGS. 14 to 17 may be implemented. In the following description of the specific die holders (72B to 72E) according to modified examples, elements configured similarly to or corresponding to those in the above-described embodiment are denoted by the same reference numerals in the drawings or by citing the same reference numerals or terms, and redundant description will be omitted.

[0085] FIG. 14 is a diagram illustrating the shape of a specific die holder 72B according to a modified example. Note that FIG. 14(a) is a view of the specific die holder 72B and the specific die 71A from the front side, and FIG. 14(b) is a view from the position of the arrow G-G in FIG. 14(a). Referring to FIG. 14, the specific die holder 72B is formed in a frame shape supporting the specific die 71A. More specifically, the specific die holder 72B does not have walls separating the top and bottom sides and a wall separating the right side, which is the downstream side in the workpiece conveyance direction, but is formed in a frame shape that is open on both the top and bottom sides and the right side. Note that in this specific die holder 72B, the specific die 71A is supported at the upper ends of the front, rear, and left walls. An opening 95 into which a stay 80 is inserted is formed in the open area on the right side of the specific die holder 72B. A specific die holder 72B having such a frame shape may also be implemented.

[0086] FIG. 15 is a diagram illustrating the shape of a specific die holder 72C according to a modified example. Note that FIG. 15(a) is a view of the specific die holder 72C and the specific die 71A from the front side, FIG. 15(b) is a view from the position of the arrows H-H in FIG. 15(a), and FIG. 15(c) is a cross-sectional view from the position of the arrows I-I in FIG. 15(b). Referring to FIG. 15, the specific die holder 72C is formed in a frame shape that supports the specific die 71A. More specifically, the specific die holder 72C does not have a wall separating the lower side or the right side, which is downstream in the workpiece conveyance direction, but is formed in a frame shape that is open on the lower and right sides. Note that in this specific die holder 72C, the specific die 71A is supported by the wall on the upper end side. An opening 95 into which the stay 80 is inserted is formed in the open area on the right side of the specific die holder 72C. Such a specific die holder 72C having a frame-like shape may be implemented.

[0087] FIG. 16 is a diagram illustrating the shape of a specific die holder 72D according to a modified example. Note that FIG. 16(a) is a view of the specific die holder 72D and the specific die 71A from the front side, FIG. 16(b) is a view as viewed from the position of the arrows J-J in FIG. 16(a), and FIG. 16(c) is a cross-sectional view as viewed from the position of the arrows K-K in FIG. 16(a). Referring to FIG. 16, the specific die holder 72D is formed in a frame shape that supports the specific die 71A. More specifically, the specific die holder 72D does not have a wall separating the right side, which is the downstream side in the workpiece conveyance direction, and is formed in a frame shape with an open right side. Note that in this specific die holder 72D, the specific die 71A is supported by the wall portion at the upper end. An opening 95 into which a stay 80 is inserted is formed in the open area on the right side of the specific die holder 72D. Furthermore, a through hole 96 is provided in the wall portion on the lower end side of the specific die holder 72D, through which the knockout pin 75 passes. Such a frame-shaped specific die holder 72D may be implemented.

[0088] FIG. 17 is a diagram illustrating the shape of a specific die holder 72E according to a modified example. Note that FIG. 17(a) is a view of the specific die holder 72E and the specific die 71A from the front side, FIG. 17(b) is a view from the position of the arrows L-L in FIG. 17(a), and FIG. 17(c) is a cross-sectional view from the position of the arrows M-M in FIG. 17(a). Referring to FIG. 17, the specific die holder 72E is formed in a frame shape that supports the specific die 71A. More specifically, the specific die holder 72E does not have a wall separating the right side, which is the downstream side in the workpiece conveyance direction, and is formed in a frame shape with an open right side. Note that in this specific die holder 72E, the specific die 71A is supported by the wall portion at the upper end. An opening 95 into which the stay 80 is inserted is formed in the open area on the right side of the specific die holder 72E. Furthermore, a recessed cutout region 97 is provided in the wall portion on the lower end side of the specific die holder 72E as a region through which the knockout pin 75 passes. The specific die holder 72E having such a frame-like shape may be implemented.

[0089] (3) In the above embodiment, the transport fingers 77 installed on the slide bars (78A, 78B) were described as including a finger main body 82 that clamps the workpiece W and an air cylinder 83 attached to the slide bars (78A, 78B) that opens and closes the finger main body 82. However, this is not necessarily the case. In the transport fingers 77, the mechanism that opens and closes the finger main body 82 does not have to be an actuator such as the air cylinder 83, but may be a mechanism that uses a compression spring and a spreader. In this modified example, for example, the finger main body 82 may be driven in the closing direction using a compression spring, and the finger main body 82 may be driven in the opening direction using a spreader.

[0090] (4) In the above-described embodiment, the configuration of the below-die removal finger 81 was described as an example, including an air cylinder 93 attached to the stay 80 and a finger main body 92 attached to the stay 80 and driven to open and close by the air cylinder 93. However, this is not necessarily the case. Alternatively, the below-die removal finger may be configured such that the stay is divided into two members, an actuator such as an air cylinder is installed in one of the two members, and the one member and the other member are connected by the actuator. Furthermore, the finger main body is installed in the other member, and the finger main body is driven to open and close together with the other member by the actuator. More preferably, a guide member may be provided to guide the other member of the stay, driven by the actuator, and the finger main body in a reciprocating movement in a direction perpendicular to the workpiece conveyance direction.

[0091] (5) In the above embodiment, the stay 80 extending from the slide bar (78A, 78B) to the lower side of the specific die 71A is fixed to the slide bar (78A, 78B), but this is not necessarily the case. The stay may be connected to the slide bar (78A, 78B) via an actuator, and the lower die removal finger attached to the stay may be driven to open and close together with the stay by the actuator. More preferably, a guide member may be provided to guide the stay and the lower die removal finger driven by the actuator as they reciprocate in a direction perpendicular to the workpiece transport direction.

[0092] (6) In the above-described embodiment, the below-die extraction finger 81 installed on the stay 80 was described as including a finger main body 92 that clamps the workpiece W and an air cylinder 93 attached to the stay 80 to open and close the finger main body 92. However, this is not necessarily the case. In the below-die extraction finger 81, the mechanism that opens and closes the finger main body 92 does not have to be an actuator such as the air cylinder 93, but may be a mechanism that uses a compression spring and a spreader. In this modified example, for example, the finger main body 92 may be driven in the closing direction using a compression spring, and the finger main body 92 may be driven in the opening direction using a spreader.

[0093] REFERENCE SIGNS LIST 1 Press system 70 Punch 71 Die 71A Specific die 72 Die holder 72A Specific die holder 73 Lower die set 74 Forming hole 76 Transfer device 77 Transport finger 78A, 78B Slide bar 79 Drive unit 80 Stay 81 Die lower removal finger W Work

Claims

1. A press system comprising a plurality of press working sections, each having a die and a punch, for performing press drawing on a workpiece multiple times, further comprising a transfer device for transporting the workpiece processed in one of the plurality of press working sections to a press working section for a next process, the transfer device comprising: a plurality of transport fingers arranged to hold the workpiece from both sides in a direction perpendicular to the transport direction of the workpiece; a pair of slide bars extending along the transport direction and on which the plurality of transport fingers are mounted; a drive unit for driving the slide bar back and forth along the transport direction; a stay extending from the slide bar towards the underside of a specific die that is the die of one of the plurality of press working sections; and an under-die removal finger mounted on the stay for holding the workpiece after it has passed through the forming hole of the specific die and moved to the underside of the specific die.

2. The press system according to claim 1, characterized in that the press processing unit having the specific die has a specific die holder that supports the specific die, and the specific die holder is provided with an opening into which the stay is inserted.

3. The press system according to claim 2, wherein the specific die holder is formed in a frame shape that supports the specific die.

4. A press system according to any one of claims 1 to 3, characterized in that the stay has a member fixed to the slide bar and extending from the slide bar toward below the specific die.

5. A press system as claimed in any one of claims 1 to 3, further comprising a lower die set on which the plurality of press working units, each having a die and a die holder supporting the die, are placed, wherein the die holders of the plurality of press working units are placed on the lower die set, and a step is formed in the lower die set so that the height position of the portion on which the specific die holder is placed is lower than the height position of the portion on which the die holder of the press working unit of a process earlier than the press working unit having the specific die holder is placed, and the height dimension of the specific die holder is set so that the height position of the upper end surface of the specific die holder matches the height position of the die holder of the press working unit of a process earlier than the press working unit having the specific die holder.

6. A press system as claimed in any one of claims 1 to 3, further comprising a lower die set on which the plurality of press working units, each having a die and a die holder supporting the die, are placed, the die holders of the plurality of press working units are placed on the lower die set, the specific die holder is arranged so that the height position of its upper end surface matches that of the die holder of the press working unit in a process earlier than the press working unit having the specific die holder, and the height dimension of the die holder of the press working unit in a process earlier than the press working unit having the specific die holder is set to match the height dimension of the specific die holder.

7. A transfer device used in a press system having a plurality of press working sections each having a die and a punch and performing press drawing on a workpiece a plurality of times, the transfer device transporting the workpiece processed in one of the plurality of press working sections to the press working section for the next process, the transfer device comprising: a plurality of transport fingers arranged to hold the workpiece from both sides in a direction perpendicular to the transport direction of the workpiece; a pair of slide bars extending along the transport direction and on which the plurality of transport fingers are installed; a drive unit that drives the slide bar back and forth along the transport direction; a stay extending from the slide bar toward the underside of a specific die that is the die of one of the plurality of press working sections; and an under-die removal finger installed on the stay that holds the workpiece after it has passed through the forming hole of the specific die and moved to the underside of the specific die.

8. A transfer device according to claim 7, wherein the stay has a member fixed to the slide bar and extending from the slide bar toward below the specific die.

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