Press molding device

Abstract

To provide a press molding device which can suppress deterioration of strength.SOLUTION: A press molding device 20 includes a die 60 having a plurality of die holes 61 where a plurality of punches 80 punching workpiece W are inserted and extracted, and a first partition wall 62 partitioning the die holes 61, and a backing plate 40 which is adjacent to the die 60 and supports the die 60. The die 60 has a plurality of die hole groups 61A including the plurality of die holes 61 which are adjacent to each other. The backing plate 40 has a plurality of backing holes 41 communicating with the plurality of die hole groups 61A, and a second partition wall 42 partitioning the backing holes 41. The second partition wall 42 has a wide part 43 which becomes continuously or gradually wider as it is spaced farther away from the die 60. The maximum width of the wide part 43 is larger than the maximum width of the first partition wall 62.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a press die device. [Background technology]

[0002] Patent Document 1 discloses a press working device including a plurality of punches, a die having a plurality of die holes through which the plurality of punches are inserted and removed, and a backing plate that is adjacent to and immediately below the die and supports the die. Note that the backing plate is referred to as a die holder in Patent Document 1.

[0003] The backing plate has a plurality of discharge holes each communicating with a corresponding one of the die holes, and the punched member punched out of the metal plate by the die and the punch is discharged from each of the discharge holes through each of the die holes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-37528 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when punched portions of a metal plate are close to each other, the die holes corresponding to these punched portions are also close to each other. As a result, the discharge holes communicating with the die holes are also close to each other. The closer the discharge holes are to each other, the smaller the width of the partition wall separating the discharge holes becomes. In this case, the strength of the backing plate required to support the die, and therefore the strength of the press die device, may decrease. [Means for solving the problem]

[0006] A press die apparatus for solving the above problem includes a die having a plurality of die holes through which a plurality of punches for punching a workpiece are inserted and removed, and a first partition wall separating the die holes, and a backing plate adjacent to the die and supporting the die, wherein the die has a plurality of die hole groups including a plurality of the die holes adjacent to each other, and the backing plate has a plurality of backing holes each communicating with the plurality of die hole groups, and a second partition wall separating the backing holes, and the second partition wall has a wide portion whose width increases continuously or stepwise as it moves away from the die, and the maximum width of the wide portion is greater than the width of the first partition wall.

[0007] According to the above configuration, since the die holes communicate with the backing holes, it is not necessary to provide partitions corresponding to all of the first partitions in the backing plate. The second partitions separating the backing holes have wide portions whose maximum width is greater than the width of the first partitions of the die. Therefore, even when the die holes are close to each other, the width of the second partitions can be prevented from becoming smaller. Therefore, the strength of the backing plate and, in turn, the strength of the press die device can be prevented from decreasing. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a rotor core according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic configuration of the press die device according to one embodiment. [Diagram 3] FIG. 3 is a top view of the die of FIG. [Figure 4] FIG. 4 is a plan view showing the backing plate of FIG. [Diagram 5] FIG. 5 is a perspective cross-sectional view showing a portion of the backing plate of FIG. 2 in cross section. [Figure 6] FIG. 6 is a plan view showing the die holder of FIG. [Figure 7] FIG. 7 is a plan view of the die, backing plate, and die holder of FIG. [Figure 8] FIG. 8 is a plan view showing a die, a backing plate, and a die holder of a modified example. [Figure 9] FIG. 9 is a cross-sectional view showing a schematic configuration of a press die device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of a press die device will be described below with reference to Fig. 1 to Fig. 7. In this embodiment, a press die device 20 used for manufacturing a rotor core for a rotating electric machine will be described.

[0010] (Rotor core 11) First, the rotor core 11 will be described. 1, rotor core 11 has a substantially cylindrical shape. Rotor core 11 is configured by stacking a plurality of core pieces 11a.

[0011] Rotor core 11 has a center hole 12 and a plurality of magnet accommodating holes 13 in which magnets (not shown) are accommodated. Rotor core 11 has, for example, 20 magnet accommodating holes 13. Center hole 12 and magnet accommodating holes 13 penetrate rotor core 11 in the axial direction. Center hole 12 and magnet accommodating holes 13 are formed by communication between through holes formed in each core piece 11a.

[0012] The magnet accommodating holes 13 are provided at intervals in the circumferential direction on the outer periphery of the rotor core 11. Each magnet accommodating hole 13 has a generally rectangular shape having long and short sides in a plan view. Two magnet accommodating holes 13 adjacent to each other in the circumferential direction are inclined in opposite directions to each other with respect to the circumferential direction.

[0013] (Press die equipment 20) 2, the press die device 20 is a device that forms a part of the core piece 11a that constitutes the rotor core 11 of the rotating electric machine by punching a workpiece W such as an electromagnetic steel plate. More specifically, the press die device 20 is a device that forms a through hole that constitutes the magnet accommodating hole 13 in the workpiece W by punching the workpiece W.

[0014] The press die device 20 includes a lower die 21 and an upper die 22 configured to be movable toward and away from the lower die 21 . (Lower mold 21) The lower die 21 includes a die holder 30, a backing plate 40, a die plate 50, and a die 60. The die holder 30 constitutes, for example, the lower part of the press die device 20. The backing plate 40 is fixed to the upper surface of the die holder 30. The die plate 50 is fixed to the upper surfaces of the die holder 30 and the backing plate 40. The die 60 is fixed to the die plate 50.

[0015] (Die 60) 3, the die 60 has a plurality of die holes 61 and a plurality of first partition walls 62 separating adjacent die holes 61. The plurality of die holes 61 are arranged in a circular shape. The die 60 has the same number of die holes 61 and first partition walls 62 as the magnet accommodating holes 13 of the rotor core 11.

[0016] A punch 80, which will be described later, is inserted into and removed from each die hole 61. The die hole 61, together with the punch 80, punches out the workpiece W, thereby forming a through hole that constitutes the magnet accommodating hole 13 in the workpiece W.

[0017] Hereinafter, the circumferential direction of the die holes 61 arranged in a circular shape is referred to as a circumferential direction C, and the radial direction of the die holes 61 is referred to as a radial direction R. Each die hole 61 has a generally rectangular shape having long sides and short sides in a plan view. Two die holes 61 adjacent to each other in the circumferential direction C are inclined in opposite directions with respect to the circumferential direction C.

[0018] The die 60 has a plurality of die hole groups 61A including a plurality of die holes 61 adjacent to each other in the circumferential direction C. Each die hole group 61A includes, for example, four die holes 61. The die 60 has, for example, five die hole groups 61A arranged in a circular shape.

[0019] The width of the die hole 61 and the width of the first partition wall 62 are constant, for example, in the axial direction of the die hole 61. Note that in this specification, the "width" refers to the width in the circumferential direction C. (Die Plate 50) 2, the die plate 50 has a holding hole 51 that holds the die 60. The holding hole 51 penetrates the die plate 50. The die 60 is fixed to the die plate 50 by being press-fitted into the holding hole 51.

[0020] (Backing Plate 40) The backing plate 40 is adjacent to and directly below the die 60 to support the die 60. The backing plate 40 is adjacent to and directly below the die plate 50 to support the die plate 50.

[0021] 4 and 5, the backing plate 40 has a plurality of backing holes 41 and a plurality of second partition walls 42 that separate adjacent backing holes 41. The backing holes 41 are arranged in a circular shape. The backing plate 40 has the same number of backing holes 41 and second partition walls 42 as the die hole group 61A.

[0022] As shown in FIG. 2, the backing holes 41 each communicate with a plurality of die hole groups 61A. The second partition 42 has a wide portion 43 whose width increases continuously the farther it is from the die 60. The wide portion 43 is provided across the entire second partition 42. The width of the wide portion 43 is smallest on the side where the die 60 is located and largest on the side opposite to the side where the die 60 is located. The maximum width of the wide portion 43 is larger than the width of the first partition 62. The minimum width of the wide portion 43 is smaller than the width of the first partition 62.

[0023] 5, a portion of the inner surface of the backing hole 41 that constitutes the wide portion 43 has an inclined surface 44 that is inclined so as to be positioned closer to the inside of the backing hole 41 as it moves away from the die 60. Thus, the backing hole 41 has a pair of inclined surfaces 44 that face each other in the circumferential direction C. The inclination angles of the pair of inclined surfaces 44 are the same.

[0024] An edge portion 45 is provided at the upper end portion, which is the end portion on the side where the die 60 is located in the wide portion 43, by continuously connecting the inclined surfaces 44 of adjacent backing holes 41. The angle formed by the two inclined surfaces 44 forming the edge portion 45 is, for example, 45° to 60°.

[0025] 2, the edge portion 45 is located directly below the first partition wall 62. This prevents scrap (not shown) generated during punching of the workpiece W from interfering with the edge portion 45 and reducing the dischargeability of the scrap.

[0026] 5, the edge portion 45 is substantially U-shaped when viewed from the circumferential direction C. Both ends of the edge portion 45 in the radial direction R are continuous with the upper surface of the backing plate 40. The portion of the edge portion 45 other than both ends in the radial direction R is located lower than the upper surface of the backing plate 40.

[0027] 2, the edge portion 45 is adjacent to the lower surface of the die 60 via a gap G. In other words, the first partition 62 and the second partition 42 face each other via the gap G. It can also be said that the backing holes 41 adjacent to each other in the circumferential direction C communicate with each other via the gap G.

[0028] (Die holder 30) 2, the die holder 30 supports the backing plate 40 adjacent to and immediately below the backing plate 40. The die holder 30 also supports the die plate 50 adjacent to and immediately below the die plate 50.

[0029] The die holder 30 has a holding recess 33 that opens toward the die 60 on the upper surface of the die holder 30 and holds the backing plate 40. The die holder 30 surrounds the outer periphery of the backing plate 40.

[0030] As shown in Fig. 6, the die holder 30 has a plurality of holder holes 31 and a plurality of third partition walls 32 separating adjacent holder holes 31. Each holder hole 31 opens to the bottom surface of the holding recess 33. The holder holes 31 are arranged in a circular shape. The die holder 30 has the same number of holder holes 31 and third partition walls 32 as the number of backing holes 41.

[0031] As shown in FIG. 2, the holder holes 31 communicate with the backing holes 41, respectively. The width of the holder hole 31 and the width of the third partition wall 32 are constant, for example, in the axial direction of the holder hole 31. The width of the holder hole 31 is larger than the minimum width of the backing hole 41 and smaller than the maximum width of the backing hole 41. The width of the third partition wall 32 is larger than the width of the first partition wall 62 and smaller than the maximum width of the second partition wall 42.

[0032] As shown in FIG. 7, the width of the holder hole 31 in the radial direction R is larger than the width of the backing hole 41 in the radial direction R. (upper mold 22) 2, the upper die 22 includes a punch plate 70 and a plurality of punches 80. The punch plate 70 is connected to a slide of a press device (not shown). Each punch 80 is held by the punch plate 70.

[0033] The multiple punches 80 are inserted into and removed from the multiple die holes 61 in conjunction with the up-and-down reciprocating motion of the slide of the press device. This punches out the workpiece W to form through holes. Scraps generated as the workpiece W is punched out pass through the die holes 61, backing holes 41, and holder holes 31 in this order, and are discharged to the outside of the lower die 21. The multiple scraps are discharged into the backing holes 41 and holder holes 31, which are connected to the multiple die holes 61.

[0034] In addition, through holes constituting the central hole 12 are formed in the workpiece W by a press die device separate from the press die device 20. Thereafter, the core pieces 11a in which the respective through holes are formed are punched out from the workpiece W.

[0035] The operation and effects of this embodiment will be described. (1) The press die device 20 includes a die 60 having a plurality of die holes 61 through which a plurality of punches 80 for punching a workpiece W are inserted and a first partition wall 62 separating the die holes 61 from each other, and a backing plate 40 adjacent to the die 60 and supporting the die 60. The die 60 has a plurality of die hole groups 61A including a plurality of die holes 61 adjacent to each other. The backing plate 40 has a plurality of backing holes 41 each communicating with the plurality of die hole groups 61A, and a second partition wall 42 separating the backing holes 41 from each other. The second partition wall 42 has a wide portion 43 whose width increases continuously with increasing distance from the die 60. The maximum width of the wide portion 43 is greater than the width of the first partition wall 62.

[0036] According to the above configuration, since the die holes 61 communicate with the backing holes 41, it is not necessary to provide partitions corresponding to all of the first partitions 62 in the backing plate 40. The second partitions 42 separating the backing holes 41 have wide portions 43 whose maximum width is greater than the width of the first partitions 62 of the die 60. Therefore, even when the die holes 61 are close to each other, it is possible to prevent the width of the second partitions 42 from becoming smaller. Therefore, it is possible to prevent a decrease in the strength of the backing plate 40, and therefore a decrease in the strength of the press die device 20.

[0037] (2) The portion of the inner surface of the backing hole 41 that constitutes the wide portion 43 has an inclined surface 44 that is inclined so as to be positioned more inward of the backing hole 41 as it moves away from the die 60 . According to the above configuration, the scrap discharged into the backing hole 41 slides down along the inclined surface 44, and is therefore easily discharged to the outside of the backing hole 41. Therefore, the dischargeability of the scrap in the press die device 20 can be improved.

[0038] (3) At the end of the wide portion 43 on the side where the die 60 is located, an edge portion 45 is provided which is formed by continuously connecting the inclined surfaces 44 of the backing holes 41 adjacent to each other.

[0039] According to the above configuration, it is possible to reduce the minimum width of the end of the wide portion 43 on the side where the die 60 is located. As a result, even if the width of the first partition wall 62 is reduced due to the distance between the die holes 61 being reduced, the distance between the backing holes 41 can be reduced. Therefore, it is possible to suppress a decrease in the strength of the backing plate 40 while reducing the distance between the backing holes 41.

[0040] (4) The die holder 30 has a plurality of holder holes 31 each communicating with a plurality of backing holes 41, and a third partition wall 32 separating the holder holes 31. The width of the third partition wall 32 is greater than the width of the first partition wall 62.

[0041] According to the above configuration, even when the die holes 61 are close to each other, it is possible to prevent the width of the third partition wall 32 separating the holder holes 31 from becoming narrow. Therefore, it is possible to prevent a decrease in the strength of the die holder 30, and therefore a decrease in the strength of the press die device 20.

[0042] (5) The multiple die holes 61 are arranged in a circular shape. According to the above configuration, the press die device 20 can be used as a device for forming a plurality of through holes arranged in a circular shape in the workpiece W. Therefore, the press die device 20 can be used for manufacturing a rotor core 11 having a plurality of magnet accommodating holes 13 arranged in a circular shape, or a stator core of a rotating electric machine having a plurality of slots arranged in a circular shape.

[0043] (6) In the die hole 61 and the backing hole 41 that communicate with each other, the first partition 62 and the second partition 42 face each other with a gap G therebetween. In order to improve the durability of the backing plate 40, it is preferable to reduce the degree of stress concentration on the second partition wall .

[0044] According to the above configuration, the first partition 62 and the second partition 42 face each other via the gap G, so that the contact area between the first partition 62 and the second partition 42 can be reduced or eliminated. Therefore, the load acting on the die 60 during use of the press die device 20 is less likely to act directly on the second partition 42. Therefore, the degree of stress concentration on the second partition 42 can be reduced.

[0045] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0046] The rotor core 11 may have a cooling passage penetrating in the axial direction radially inward of the magnet accommodating hole 13. In this case, as shown in FIG. 8, the die 60 may have a first die hole 63 and a second die hole 64. The first die hole 63 punches out a through hole constituting the magnet accommodating hole 13 from the workpiece W together with the punch 80. The second die hole 64 punches out a through hole constituting the cooling passage from the workpiece W together with the punch 80. The die hole group 61A in this modification example is composed of four first die holes 63 and two second die holes 64. In this configuration, six scraps are discharged through the first die hole 63 and the second die hole 64 to one backing hole 41 and holder hole 31.

[0047] There may be no gap G between the edge 45 and the lower surface of the die 60. In this case, the entire edge 45 is located at the same height as the upper surface of the backing plate 40, so that the entire edge 45 contacts the first partition wall 62.

[0048] The die holes 61 are not limited to being arranged in a circular shape, and may be arranged, for example, in a straight line. That is, the press die device 20 is not limited to being used to form the core pieces 11a, and may be used to form, for example, a plurality of through holes arranged in a straight line in the workpiece W.

[0049] The width of the holder hole 31 may increase as it is farther away from the backing plate 40. In other words, the width of the third partition wall 32 may decrease as it is farther away from the backing plate 40. Even in this case, it is preferable that the maximum width of the third partition wall 32 is greater than the width of the first partition wall 62.

[0050] The width of the third partition 32 may be equal to or smaller than the width of the first partition 62 . The edge portion 45 may be formed by two inclined surfaces 44 and a flat surface connecting the two inclined surfaces 44. In this case, the width of the upper end portion of the wide portion 43 can be increased.

[0051] The portion of the inner surface of the backing hole 41 that constitutes the wide portion 43 may have a curved surface that is convex toward one side or the other side in the circumferential direction C. The width of the die hole 61 may be increased as it approaches the backing plate 40. In other words, the width of the first partition wall 62 may be decreased as it approaches the backing plate 40. Even in this case, it is preferable that the maximum width of the wide portion 43 is larger than the maximum width of the first partition wall 62.

[0052] The wide portion 43 may have a width that gradually increases as it moves away from the die 60. In this case, the portion of the inner surface of the backing hole 41 that constitutes the wide portion 43 has a stepped inner surface. 9, the second partition wall 42 may have a straight portion extending linearly along the first partition wall 62 directly below the first partition wall 62, and a wide portion 43 connected to the straight portion. In this case, scrap pieces immediately after being discharged from each die hole 61 are less likely to interfere with each other, thereby improving the dischargeability of scrap in the press die device 20.

[0053] The above embodiment includes the configurations described in the following supplementary notes. [Appendix 1] A press die apparatus comprising: a die having a plurality of die holes through which a plurality of punches for punching a workpiece are inserted and a first partition wall separating the die holes; and a backing plate adjacent to the die and supporting the die, wherein the die has a plurality of die hole groups including a plurality of the die holes adjacent to each other, and the backing plate has a plurality of backing holes respectively communicating with the plurality of die hole groups and a second partition wall separating the backing holes, the second partition wall having a wide portion whose width increases continuously or stepwise as it moves away from the die, and the maximum width of the wide portion is greater than the width of the first partition wall.

[0054] [Appendix 2] The press die apparatus described in [Appendix 1], wherein the portion of the inner surface of the backing hole that constitutes the wide portion has an inclined surface that is inclined so as to be positioned more inward of the backing hole as it moves away from the die.

[0055] [Appendix 3] A press die apparatus as described in [Appendix 2], in which the end of the wide portion on the side where the die is located is provided with an edge portion formed by continuously connecting the inclined surfaces of adjacent backing holes.

[0056] [Appendix 4] A press die apparatus described in any one of [Appendix 1] to [Appendix 3], comprising a die holder adjacent to the backing plate and supporting the backing plate, the die holder having a plurality of holder holes each communicating with the plurality of backing holes, and a third partition wall separating the holder holes, wherein the width of the third partition wall is greater than the width of the first partition wall.

[0057] [Appendix 5] A press die apparatus according to any one of [Appendix 1] to [Appendix 4], wherein the plurality of die holes are arranged in a circular shape. [Explanation of symbols]

[0058] G…Gap W…Work 11...Rotor core 11a...Iron core piece 12...Center hole 13...Magnet receiving hole 20... Press die equipment 21…Lower mold 22…Upper mold 30…Die holder 31...Holder hole 32...Third bulkhead 33…Retaining recess 40…Backing plate 41…Backing hole 42…Second bulkhead 43…Wide section 44…Slope surface 45…Edge 50…Die plate 51...Retaining hole 60…Die 61…Die hole 61A…Die hole group 62...First bulkhead 63…First die hole 64…Second die hole 70…Punch plate 80...Punch

Claims

1. A die having a plurality of die holes into which a plurality of punches for punching a workpiece are inserted and a first partition wall separating the die holes from each other; A backing plate that supports the die adjacent to the die, The die has a plurality of die hole groups including a plurality of the die holes adjacent to each other, the backing plate has a plurality of backing holes respectively communicating with the plurality of die hole groups, and a second partition wall separating the backing holes from each other, the second partition has a wide portion whose width increases continuously or stepwise as it moves away from the die, The maximum width of the wide portion is greater than the width of the first partition wall. Press die equipment.

2. a portion of the inner surface of the backing hole constituting the wide portion has an inclined surface that is inclined so as to be positioned closer to the inside of the backing hole as it moves away from the die; The press die apparatus according to claim 1 .

3. an edge portion is provided at an end portion of the wide portion on the side where the die is located, the edge portion being formed by continuously connecting the inclined surfaces of the backing holes adjacent to each other; The press die apparatus according to claim 2 .

4. a die holder adjacent to and supporting the backing plate; The die holder includes: a plurality of holder holes respectively communicating with the plurality of backing holes; and a third partition wall separating the holder holes from each other, The width of the third partition is greater than the width of the first partition. The press die apparatus according to claim 1 .

5. The die holes are arranged in a circular shape. The press die apparatus according to any one of claims 1 to 4.

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