Press die

Abstract

To provide a press die that can suppress scrap rising.SOLUTION: A press die 10 comprises a punch 40, and a base part 30 to which the punch 40 is fixed. The punch 40 comprises: a punch body 50 with a housing hole 51; an ejector pin 60 housed in the housing hole 51; and an energizing member 70 housed in the housing hole 51. The ejector pin 60 has a communication hole 63 which penetrates the ejector pin 60 in an axial direction of the punch body 50, and which communicates with the inside and the outside of the housing hole 51. The energizing member 70 forms a gap that allows circulation of air, between itself and an inner surface of the housing hole 51. The press die 10 is provided with an exhaust passage D which includes the housing hole 51, and exhausts air having flown into the housing hole 51 through the communication hole 63, to the outside.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses, as a prior art of the invention described in Patent Document 1, a jector punch including a punch body having a through hole and a jector pin disposed inside the through hole. The jector pin is configured to be able to protrude and retract from the tip face of the punch body.

[0003] A coil spring is provided inside the through hole for biasing the jector pin so as to protrude from the tip surface of the punch body. The coil spring is disposed between the screw screwed into the through portion and the jector pin. The jector pin retreats into the punch body against the biasing force of the coil spring while the punch body is punching the workpiece, but protrudes from the punch body when punching of the workpiece is completed. This causes scrap punched out of the workpiece to be pulled away from the punch body, thereby suppressing scrap lift-up. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-7686 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the jector pin described in Patent Document 1, the space between the jector pin and the punched waste may be in a vacuum state lower than atmospheric pressure, causing the punched waste to be attracted to the jector pin. In this case, the punched waste may be separated from the punch body but not from the jector pin. For this reason, there is room for improvement in suppressing the scrap lift-up. [Means for solving the problem]

[0006] A press die for solving the above problem is a press die including a punch and a base portion fixed to a slide of a press machine and to which the punch is fixed, wherein the punch has an accommodating hole that opens toward a die and cooperates with the die to punch out a workpiece, an ejector pin that is accommodated in the accommodating hole and is configured to be able to protrude and retract from a tip end surface of the punch body and ejects scrap punched out of the workpiece by the punch body from the tip end surface of the punch body, and a biasing member that is accommodated in the accommodating hole and constantly biases the ejector pin in the ejection direction of the ejector pin, wherein the ejector pin has a communication hole that penetrates the ejector pin in the axial direction of the punch and communicates between the inside and the outside of the accommodating hole, and the biasing member forms a gap between the inner surface of the accommodating hole and the biasing member to allow air to flow, and a discharge path that includes the accommodating hole and discharges air that has flowed into the accommodating hole through the communication hole to the outside is provided.

[0007] According to the above configuration, when the punch body punches the workpiece, the air that has flowed into the accommodation hole through the communication hole of the ejector pin is discharged to the outside of the punch body through the discharge path including the accommodation hole. This makes it possible to prevent a vacuum state lower than atmospheric pressure from being created between the scrap punched out of the workpiece and the ejector pin. This allows the scrap to be suitably discharged from the punch body by the ejector pin. This makes it possible to prevent scrap from floating up. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a press die according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a state in which the ejector pin of FIG. 1 is retracted inside the punch body. [Diagram 3] FIG. 3 is a cross-sectional view showing a state in which the ejector pin of FIG. 1 ejects scrap. [Figure 4]FIG. 4 is a cross-sectional view showing a press die according to a first modified example. [Diagram 5] FIG. 5 is a cross-sectional view showing a press die according to a second modified example. [Figure 6] FIG. 6 is a cross-sectional view showing a press die according to a third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, one embodiment of a press die will be described with reference to FIGS. (Press mold 10) 1, the press die 10 includes a die 20, a base portion 30, a punch 40, a bolt 90, and a stripper plate 100. The press die 10 punches out a thin plate-like workpiece W by cooperation between the die 20 and the punch 40 which advances and retreats relative to the die 20.

[0010] Hereinafter, the axial direction of the punch 40 will be simply referred to as the axial direction. The axial direction coincides with the direction in which the punch 40 advances and retreats. (Die 20) The die 20 is in the shape of a block having a mounting surface on which the workpiece W is placed. The die 20 is fixed to a fixed die set (not shown). The die 20 has a die hole 21 that opens to the mounting surface and passes through the die 20. A punch 40 is inserted into the die hole 21 when punching the workpiece W.

[0011] (Base part 30) The base part 30 includes a movable die set 31 and a backing plate 32. The movable die set 31 is fixed to the underside of a slide 110 of a press machine that is raised and lowered by a driving device (not shown). The backing plate 32 is fixed to the underside of the movable die set 31. The base part 30 advances and retreats relative to the die 20 as the slide 110 rises and falls.

[0012] The base portion 30 has a bolt receiving hole 33 for receiving a bolt 90, which will be described later. The bolt receiving hole 33 passes through the movable die set 31 and the backing plate 32 in the axial direction.

[0013] The bolt accommodating hole 33 has a first small diameter portion 34 and a first large diameter portion 35. The cross-sectional shape of the first small diameter portion 34 and the first large diameter portion 35 perpendicular to the axial direction is, for example, circular. The first large diameter portion 35 has a larger diameter than the first small diameter portion 34. The first small diameter portion 34 opens to the lower surface of the backing plate 32. The first large diameter portion 35 is connected to the upper end of the first small diameter portion 34 inside the backing plate 32. The first large diameter portion 35 includes a through hole 35a that passes through the movable die set 31 in the vertical direction. That is, the first large diameter portion 35 is formed across the movable die set 31 and the backing plate 32.

[0014] The movable die set 31 has a contact surface 36 that contacts the lower surface of the slide 110. A communication groove 37 that communicates between the inside and the outside of the bolt accommodating hole 33 is formed in the contact surface 36. Both ends in the longitudinal direction of the communication groove 37 open to the inner surface of the through hole 35a and the outer surface of the movable die set 31, respectively. The upper opening of the communication groove 37 is closed by the lower surface of the slide 110.

[0015] (Punch 40) The punch 40 includes a punch body 50, an ejector pin 60, a biasing member 70, and a fixed member 80. The punch 40 is fixed to the base portion 30. The punch body 50, the ejector pin 60, the biasing member 70, and the fixed member 80 are coaxially arranged.

[0016] (Punch body 50) The punch body 50 has a columnar shape. The punch body 50 cooperates with the die 20 to punch out the workpiece W. The punch body 50 has an accommodating hole 51 that opens toward the die 20. The accommodating hole 51 penetrates the punch body 50 in the axial direction.

[0017] The receiving hole 51 has a second small diameter portion 52 and a second large diameter portion 53. The cross-sectional shape perpendicular to the axial direction of the second small diameter portion 52 and the second large diameter portion 53 is, for example, circular. The second large diameter portion 53 has a larger diameter than the second small diameter portion 52. The second small diameter portion 52 opens to the tip surface of the punch body 50. The second large diameter portion 53 is connected to the upper end of the second small diameter portion 52. The second large diameter portion 53 communicates with the first small diameter portion 34 of the bolt receiving hole 33.

[0018] (Ejector pin 60) The ejector pin 60 has a columnar shape. The ejector pin 60 is configured to be able to appear and disappear from the tip surface of the punch body 50, i.e., the contact surface of the punch body 50 with the workpiece W. The ejector pin 60 ejects scrap punched out of the workpiece W by the punch body 50 from the tip surface of the punch body 50, i.e., pulls the scrap away from the tip surface of the punch body 50.

[0019] The ejector pin 60 has a discharging portion 61 and a flange portion 62. The discharging portion 61 constitutes the lower end portion of the ejector pin 60. The flange portion 62 constitutes the upper end portion of the ejector pin 60. The discharging portion 61 discharges scrap from the tip surface of the punch body 50. The discharging portion 61 is cylindrical. The flange portion 62 has a larger diameter than the discharging portion 61.

[0020] The ejector pin 60 has a communication hole 63 that penetrates the ejector pin 60 in the axial direction and communicates between the inside and the outside of the accommodation hole 51. The cross-sectional shape of the communication hole 63 perpendicular to the axial direction is, for example, a circle. The communication hole 63 penetrates the dispensing portion 61 and the flange portion 62.

[0021] (biasing member 70) The biasing member 70 is accommodated in the accommodation hole 51. The biasing member 70 is disposed between the ejector pin 60 and a fixing member 80 described later. The biasing member 70 constantly biases the ejector pin 60 in the ejection direction of the ejector pin 60. The biasing member 70 is a compression coil spring.

[0022] A gap that allows air to flow is formed between the biasing member 70 and the inner surface of the accommodation hole 51. In other words, the biasing member 70 is accommodated in the accommodation hole 51 without blocking the accommodation hole 51.

[0023] (Fixing member 80) The fixing member 80 is accommodated in the accommodation hole 51. The fixing member 80 is, for example, a set screw. The fixing member 80 is fixed to the punch body 50 by being screwed into the second large diameter portion 53. The fixing member 80 contacts an end of the urging member 70 located on the opposite side to the ejector pin 60. In this way, the fixing member 80 positions the urging member 70.

[0024] The fixed member 80 has a first through hole 81 that passes through the fixed member 80 in the axial direction. The cross-sectional shape of the first through hole 81 perpendicular to the axial direction is, for example, circular. The diameter of the first through hole 81 is, for example, larger than the diameter of the communication hole 63 and smaller than the inner diameter of the biasing member 70.

[0025] (Bolt 90) The bolt 90 fixes the punch body 50 to the base portion 30. The bolt 90 is screwed into the second large diameter portion 53 of the bolt accommodating hole 51 while being accommodated in the bolt accommodating hole 33. The tip portion of the bolt 90 is spaced from the fixing member 80 in the axial direction.

[0026] The bolt 90 has a second through hole 91 that passes through the bolt 90 in the axial direction. The upper end of the second through hole 91 is configured as an engagement recess 92 formed in the head of the bolt 90. The engagement recess 92 is a recess into which a tool for screwing the bolt 90 engages.

[0027] The cross-sectional shape of the engagement recess 92 perpendicular to the axial direction is, for example, a polygon. The cross-sectional shape of the second through-hole 91 perpendicular to the axial direction of the portion excluding the engagement recess 92 is, for example, a circle. The diameter of the above-mentioned portion of the second through-hole 91 is smaller than the diameter of the first through-hole 81, for example.

[0028] The communication hole 63, the first through hole 81, and the second through hole 91 are positioned coaxially. (Discharge path D) The press die 10 is provided with an exhaust path D that exhausts air that has flowed into the accommodating hole 51 through the communication hole 63 to the outside via the communication groove 37. The exhaust path D includes the accommodating hole 51, the first through hole 81 of the fixing member 80, the second through hole 91 of the bolt 90, the bolt accommodating hole 33 of the base portion 30, and the communication groove 37. The accommodating hole 51, the first through hole 81, the second through hole 91, and the bolt accommodating hole 33 that constitute the exhaust path D are positioned coaxially.

[0029] (Stripper plate 100) The stripper plate 100 is constantly biased toward the die 20 by a spring (not shown) attached to the base portion 30. The stripper plate 100 presses the workpiece W against the die 20 when punching the workpiece W. The stripper plate 100 has a through hole 101 into which the punch 40 is inserted.

[0030] <Action of this embodiment> 2, when punching the workpiece W, the slide 110 descends, causing the punch 40 and the stripper plate 100 to descend toward the die 20. The stripper plate 100 comes into contact with the workpiece W, pressing the workpiece W against the die 20. The punch 40 then descends with the stripper plate 100 pressing the workpiece W against the die 20. As the punch 40 descends, the ejector pin 60 protruding from the punch body 50 comes into contact with the workpiece W, and the ejector pin 60 retreats into the punch body 50 against the biasing force of the biasing member 70. The tip surface of the punch body 50 then comes into contact with the workpiece W.

[0031] 3, when the punch 40 further descends, the workpiece W is punched out by the die 20 and the punch body 50. The ejector pin 60 is constantly biased in the ejection direction of the ejector pin 60 by the biasing member 70. Therefore, the scrap punched out from the workpiece W is ejected from the tip surface of the punch body 50 by the ejector pin 60 protruding from the punch body 50.

[0032] 2, when punching the workpiece W, the air that has flowed into the accommodation hole 51 through the communication hole 63 of the ejector pin 60 is discharged to the outside of the punch body 50 through the discharge path D including the accommodation hole 51. This makes it possible to prevent a vacuum state lower than atmospheric pressure from being created between the scrap punched out of the workpiece W and the ejector pin 60.

[0033] <Effects of this embodiment> (1) The ejector pin 60 has a communication hole 63 that penetrates the ejector pin 60 in the axial direction of the punch body 50 and communicates between the inside and the outside of the accommodation hole 51. The press die 10 is provided with a discharge path D that includes the accommodation hole 51 and discharges air that has flowed into the accommodation hole 51 through the communication hole 63 to the outside.

[0034] According to the above-mentioned configuration, scrap is suitably ejected from the punch body 50 by the ejector pin 60. Therefore, it is possible to prevent the scrap from floating up. (2) The fixing member 80 has a first through hole 81. The discharge path D includes the first through hole 81.

[0035] According to the above configuration, since the fixed member 80 that contacts the end of the urging member 70 has the first through hole 81, it is possible to form the discharge path D by utilizing the fixed member 80. This eliminates the need to separately provide a flow path or the like that forms the discharge path D inside the punch body 50. Therefore, the discharge path D can be realized with a simple configuration.

[0036] (3) The base portion 30 has a bolt accommodating hole 33. The bolt 90 has a second through hole 91. The discharge passage D includes the second through hole 91 and the bolt accommodating hole 33. According to the above configuration, since the bolt 90 that fixes the punch body 50 to the base portion 30 has the second through hole 91, the discharge path D can be formed by using the bolt 90 and the base portion 30. This eliminates the need to separately provide a flow path or the like that forms the discharge path D inside the punch body 50. Therefore, the discharge path D can be realized with a simple configuration.

[0037] (4) The communication hole 63, the first through hole 81, and the second through hole 91 are positioned coaxially. According to the above configuration, when configuring the discharge path D, it is possible to suppress an increase in size in a direction perpendicular to the axial direction of the ejector pin 60, the fixing member 80, and the bolt 90. Therefore, an increase in size of the punch 40, and therefore an increase in size of the press die 10, can be suppressed.

[0038] Moreover, according to the above-mentioned configuration, the discharge path D can be set even with a small-diameter punch. (5) A communication groove 37 that communicates between the inside and the outside of the bolt receiving hole 33 is formed on the contact surface 36 of the base portion 30. The discharge path D includes the communication groove 37.

[0039] According to the above configuration, the drain path D is configured by forming the communication groove 37 on the contact surface 36 of the base portion 30. Therefore, for example, compared to the case where a communication hole that communicates between the inside and the outside of the bolt accommodating hole 33 is formed in the base portion 30, the drain path D can be realized more easily.

[0040] <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.

[0041] The tip of the dispensing portion 61 may be semi-spherical. The fixing member 80 does not have to be screwed into the second large diameter portion 53. The fixing member 80 may be fixed to the punch body 50 by, for example, being press-fitted into the second large diameter portion 53.

[0042] As shown in FIG. 4, the press die 10 may include a plurality of ejector pins 60 and a plurality of biasing members 70 that constantly bias each of the ejector pins 60. In this case, the punch body 50 has a plurality of accommodation holes 51 that accommodate each of the ejector pins 60. In addition, the press die 10 is provided with a discharge path D for each of the accommodation holes 51. In this way, when the punch 40 includes a plurality of ejector pins 60, the scrap is likely to be easily discharged from the punch body 50, but may also be easily attracted to the ejector pins 60. In this regard, according to this modification, it is possible to prevent the space between the scrap and each of the ejector pins 60 from becoming a vacuum state lower than atmospheric pressure. Therefore, it is possible to prevent the scrap from floating up.

[0043] The base portion 30 does not have to have the communication groove 37. In this case, the discharge path D only needs to have, for example, a communication hole that connects the inside and outside of the base portion 30. The communication hole 63, the first through hole 81, and the second through hole 91 do not have to be positioned coaxially.

[0044] 5, if a communication hole 51a that communicates between the inside and outside of the accommodating hole 51 is provided on the inner surface of the accommodating hole 51, the bolt 90 may not have the second through hole 91. The communication hole 51a is provided, for example, in a portion of the inner surface of the accommodating hole 51 that is above the fixing member 80. In this case, the discharge path D includes the accommodating hole 51, the first through hole 81, and the communication hole 51a. Although not shown, if a communication hole 51a is provided in a portion of the inner surface of the accommodating hole 51 that faces the biasing member 70, the fixing member 80 may not have the first through hole 81. In this case, the discharge path D includes the accommodating hole 51 and the communication hole 51a.

[0045] 6 , if the biasing member 70 is disposed between the ejector pin 60 and the bolt 90, the press die 10 does not need to include the fixing member 80. In this case, the discharge passage D includes the accommodation hole 51, the second through hole 91, and the bolt accommodation hole 33.

[0046] The biasing member 70 may be a leaf spring. In this case, the biasing member 70 may have a gap between itself and the inner surface of the accommodation hole 51, or may have a through hole that passes through the biasing member 70 in the axial direction. This gap and the through hole function as a space that allows air to pass through.

[0047] <Additional Notes> The above embodiment includes the configurations described in the following supplementary notes. [Appendix 1] A press die comprising: a punch; and a base portion fixed to a slide of a press machine and to which the punch is fixed, wherein the punch has an accommodation hole that opens toward a die and cooperates with the die to punch out a workpiece; an ejector pin that is accommodated in the accommodation hole and is configured to be able to protrude and retract from a tip end face of the punch body and ejects scrap punched out of the workpiece by the punch body from the tip end face of the punch body; and a biasing member that is accommodated in the accommodation hole and constantly biases the ejector pin in the ejection direction of the ejector pin, wherein the ejector pin has a communication hole that penetrates the ejector pin in the axial direction of the punch and communicates between the inside and the outside of the accommodation hole, and the biasing member forms a gap between the inner surface of the accommodation hole and the accommodation hole to allow air to flow, and a discharge path that includes the accommodation hole and discharges air that has flowed into the accommodation hole through the communication hole to the outside is provided.

[0048] [Appendix 2] A press die as described in [Appendix 1], comprising a fixing member that is fixed inside the accommodating hole and contacts an end of the biasing member that is located on the opposite side to the ejector pin, the fixing member having a through hole that passes through the fixing member in the axial direction, and the discharge passage includes the through hole.

[0049] [Appendix 3] A press die according to [Appendix 1] or [Appendix 2], comprising a bolt that is screwed into the accommodating hole and fixes the punch body to the base portion, the base portion having a bolt accommodating hole that penetrates the base portion in the axial direction and accommodates the bolt, the bolt having a through hole that penetrates the bolt in the axial direction, and the discharge passage including the through hole of the bolt and the bolt accommodating hole.

[0050] [Appendix 4] The press die according to [Appendix 2], wherein when the through hole is a first through hole, a bolt is provided that is screwed into the accommodating hole and fixes the punch body to the base portion, the base portion has a bolt accommodating hole that penetrates the base portion in the axial direction and accommodates the bolt, the bolt has a second through hole that penetrates the bolt in the axial direction, the discharge passage includes the second through hole and the bolt accommodating hole, and the communicating hole, the first through hole, and the second through hole are positioned coaxially.

[0051] [Appendix 5] A press die described in [Appendix 3] or [Appendix 4], wherein a communicating groove connecting the inside and outside of the bolt accommodating hole is formed on the contact surface of the base portion with the slide, and the discharge passage includes the communicating groove.

[0052] [Appendix 6] A press die described in any one of [Appendix 1] to [Appendix 5], wherein the punch comprises a plurality of ejector pins and a plurality of biasing members that constantly bias each of the plurality of ejector pins in the ejection direction, the punch body has a plurality of accommodating holes that accommodate each of the plurality of ejector pins, and a plurality of discharge paths are provided for each of the plurality of accommodating holes. [Explanation of symbols]

[0053] D...Discharge path W…Work 10... Press mold 20…Die 21…Die hole 30…Base section 31…Movable die set 32…Backing plate 33...Bolt receiving hole 34...First small diameter section 35…First large diameter section 35a...Through hole 36…Contact surface 37…Communication groove 40...Punch 50…Punch body 51...Housing hole 51a...Communication hole 52…Second small diameter section 53…Second large diameter section 60...Ejector pin 61...Payment section 62…Flange 63…Communication hole 70... Urging member 80…Fixing member 81…First through hole 90…Volts 91…Second through hole 92...Engagement recess 100...Stripper plate 101...Through hole 110…Slide

Claims

1. Punch and A press die including: a base portion fixed to a slide of a press machine and to which the punch is fixed; The punch is A punch body having an accommodation hole that opens toward a die and punches out a workpiece in cooperation with the die; an ejector pin that is accommodated in the accommodation hole and is configured to be able to protrude into and retract from a tip end surface of the punch body, and that ejects scrap punched out of the work by the punch body from the tip end surface of the punch body; a biasing member that is accommodated in the accommodation hole and constantly biases the ejector pin in the ejection direction of the ejector pin, the ejector pin has a communication hole that penetrates the ejector pin in an axial direction of the punch and communicates between the inside and the outside of the accommodation hole, a gap that allows air to pass between the biasing member and an inner surface of the receiving hole, a discharge passage including the accommodation hole and configured to discharge the air that has flowed into the accommodation hole through the communication hole to the outside; Press mold.

2. a fixing member fixed inside the receiving hole and in contact with an end of the biasing member located on an opposite side to the ejector pin, The fixing member has a through hole passing through the fixing member in the axial direction, The discharge path includes the through hole. The press die according to claim 1 .

3. a bolt that is screwed into the receiving hole and fixes the punch body to the base portion; the base portion has a bolt accommodating hole that penetrates the base portion in the axial direction and accommodates the bolt, The bolt has a through hole passing through the bolt in the axial direction, The discharge passage includes the through hole and the bolt accommodating hole. The press die according to claim 1 .

4. When the through hole is a first through hole, a bolt that is screwed into the receiving hole and fixes the punch body to the base portion; the base portion has a bolt accommodating hole that penetrates the base portion in the axial direction and accommodates the bolt, The bolt has a second through hole passing through the bolt in the axial direction, The discharge passage includes the second through hole and the bolt accommodating hole, The communication hole, the first through hole, and the second through hole are coaxially positioned. The press die according to claim 2.

5. A communication groove is formed on a contact surface of the base portion with the slide, the communication groove communicating the inside and outside of the bolt receiving hole, The discharge passage includes the communication groove. The press die according to claim 3 or 4.

6. The punch includes a plurality of the ejector pins and a plurality of the urging members that constantly urge each of the plurality of ejector pins toward the dispensing direction, the punch body has a plurality of accommodating holes for accommodating the plurality of ejector pins, The discharge passage is provided for each of the plurality of receiving holes. The press die according to claim 1 .

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