Caulking jig, die set using caulking jig, and manufacturing method for caulking jig

Abstract

To provide a caulking jig enabling caulking, simultaneously in a radial direction of the work piece, a plurality of parts of a work piece in a circumferential direction of the work piece.SOLUTION: A caulking jig 10 has a body 11 made of a wear-resistant metal. A tapered surface 13 is formed on an outer periphery of a tip part 11b of the body 11. The tapered surface 13 has a shape becoming smaller in diameter toward an end face 11c of the body 11. A center hole 20 is formed in the body 11. Slits 41, 42, 43, 44 are formed at a plurality of positions in a circumferential direction of the body 11. The slits 41, 42, 43, 44 extend in a direction along an axis X1 from the end face 11c of the body 11 to a certain position L2 in a longitudinal direction of the body 11. The chuck elements 51, 52, 53, 54 are formed between the slits 41, 42, 43, 44 adjacent to one another in the circumferential direction of the body 11. Punching portions 31, 32, 33, 34 are respectively formed at tips of the chuck elements 51, 52, 53, 54.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a clamping jig for clamping a workpiece, a mold set using the clamping jig, and a method for manufacturing the clamping jig.

Background Art

[0002] As an example of a workpiece, a composite member composed of a first part and a second part is known. In order to fix the first part and the second part to each other, a plastic working called crimping may be applied. For example, in a state where a part of the second part is inserted into the first part, a local load is applied from the outside to a part of the first part. By plastically deforming a part of the first part in the radial direction toward the second part by this load, both can be fixed.

[0003] In one example of a conventional device, the workpiece is plastically deformed by applying a radial load from the outside at one location in the circumferential direction of the workpiece. However, in such a conventional device, the workpiece is deformed unevenly, so the appearance deteriorates. Moreover, since the crimping portion is offset to one location in the circumferential direction of the workpiece, the strength of the crimping portion tends to be unstable. In another conventional device, crimping portions are formed at two locations in the circumferential direction of the workpiece by applying loads from both sides in the radial direction of the workpiece. However, there is a possibility that the central axis of the first part and the central axis of the second part may be displaced from each other.

[0004] In yet another conventional device, a plurality of striking members arranged in the circumferential direction of the workpiece are used to perform a diameter reduction process on the workpiece. For example, the processing device described in Patent Document 1 has an inner disk, an outer disk rotatably arranged outside the inner disk, and a plurality of striking members arranged at a plurality of locations in the circumferential direction of the inner disk. When the outer disk rotates, the plurality of striking members move toward the workpiece, and the workpiece is plastically processed.

[0005] In the field of plastic processing, in addition to Patent Document 1, a rotary forging device called a rotary swaging machine is also known (for example, Patent Document 2). An example of a rotary swaging machine has a plurality of striking members arranged in the circumferential direction of the workpiece. By striking the workpiece radially from the outside with these striking members, the diameter of the workpiece can be reduced.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] According to the processing device described in Patent Document 1 and the swaging machine described in Patent Document 2, the entire circumference of a cylindrical metal workpiece can be plastically deformed substantially evenly. However, these conventional devices require a great deal of equipment overall. Moreover, since the gripping margin of the workpiece (the part that grips the workpiece) is large, it has been difficult to clamp a minute workpiece.

[0008] An object of the present invention is to provide a clamping jig capable of clamping a plurality of locations in the circumferential direction of a workpiece in the radial direction of the workpiece at the same time, a die set, and a method for manufacturing the clamping jig.

Means for Solving the Problems

[0009] One embodiment is a clamping jig for clamping a workpiece, which has a body. This body includes a center hole, a plurality of slits, a plurality of chuck elements, a punch portion, and an opening for inserting the workpiece. The center hole is formed inside the body and extends in a direction along the axis of the body.

[0010] The plurality of slits are formed at a plurality of locations on the body, each opening to the outer surface and the inner surface of the body, and extending in a direction along the axis. The plurality of chuck elements are formed between the adjacent slits of the body. The punch portions are respectively formed on the inner surfaces of the plurality of chuck elements facing the center holes, and protrude in directions facing each other. The opening is formed on an end surface of the body and is located on the axis. The number of punch portions is plural according to the number of slits.

[0011] The caulking jig of the present embodiment may have a tapered surface. This tapered surface is formed on the outer surface of the end portion of the body and has a shape in which the width becomes smaller toward the end surface of the body. The slit may be formed from the end surface of the body to a position in the middle of the length direction of the body. Each of the plurality of chuck elements is elastically deformable in a direction in which the punch portions approach each other. A circular hole for reducing stress concentration may be provided at the end of the slit.

[0012] One embodiment of a mold set including the caulking jig includes a lower mold that supports the caulking jig, a movable mold, and a pressing member. The movable mold has a hole into which the body is inserted, and has a cam surface in contact with the body on the inner periphery of this hole. The pressing member moves the movable mold in a direction along the axis with respect to the caulking jig.

[0013] In the mold set according to one embodiment, it may have a work support member inserted into the center hole of the caulking jig, and the work support portion may have a work holding portion for holding the work in a state where the work is inserted into the opening.

[0014] One manufacturing method according to an embodiment for manufacturing the clamping jig includes forming the plurality of slits in an intermediate product as the material of the clamping jig, forming the center hole in the intermediate product by electrical discharge machining, and when forming the center hole by electrical discharge machining, using an X-ray fluoroscope to confirm the position of the tip of the center hole by fluoroscopy, machining the punch portion into a predetermined shape, and machining the end face of the body such that the distance from the tip of the center hole to the end face of the body becomes a predetermined value.

Advantages of the Invention

[0015] According to the clamping jig and the mold set according to one embodiment, a plurality of locations of the workpiece can be clamped simultaneously from the outside of the workpiece. Moreover, even a small workpiece can be clamped. According to the manufacturing method according to one embodiment, a clamping jig made of a hard metal material such as tool steel can be machined with high precision.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0017] Hereinafter, the crimping tool 10 according to the first embodiment will be described with reference to FIGS. 1 to 6. FIG. 1 is a perspective view of the crimping tool 10. FIG. 2 is a front view of the crimping tool 10, and FIG. 3 is a plan view of the crimping tool 10. FIG. 4 is an enlarged plan view of a part (punching portion) of the crimping tool 10.

[0018] The crimping tool 10 of the present embodiment includes a body 11, a flange portion 12 formed on a base portion 11a of the body 11, and a tapered surface 13 formed on an outer periphery of a tip portion 11b of the body 11. The body 11 of the present embodiment has a substantially cylindrical shape. However, a shape other than a cylinder, for example, a polygon such as a quadrangle in cross section may be used. In the case of the present embodiment, the tip portion 11b of the body 11 including the tapered surface 13 has a shape close to a frustum of a cone. The tapered surface 13 has a smaller diameter toward the end surface 11c of the body 11. That is, when the body 11 is viewed from the side as shown in FIG. 2, the width of the tapered surface 13 becomes smaller toward the end surface 11c of the body 11. Further, the tapered surface 13 forms a first angle θ1 with respect to a virtual line segment L1 extending in the longitudinal direction (direction along the axis X1) of the body 11.

[0019] The clamping jig 10 is integrally formed of a metal material such as steel. An example of the metal material is tool steel (e.g., SKH51 high-speed steel) excellent in wear resistance and toughness, but other steel types may be adopted. The chemical composition (%) of SKH51 high-speed steel is C: 0.80 - 0.88, Si: 0.45 or less, Mn: 0.40 or less, P: 0.030 or less, S: 0.030 or less, Cr: 3.80 - 4.50, Mo: 4.70 - 5.20, W: 5.90 - 6.70, V: 1.70 - 2.10, Cu: 0.25 or less.

[0020] As shown in FIG. 2, the axis X1 of the body 11 passes through the center of the body 11 and extends in the longitudinal direction of the body 11. The end face 11c of the body 11 is a plane perpendicular to the axis X1. The tapered surface 13 is rotationally symmetric about the axis X1 and has a smaller diameter toward the end face 11c of the body 11.

[0021] In this specification, the direction along the axis X1 is referred to as the longitudinal direction of the body 11, and the direction perpendicular to the axis X1 is referred to as the radial direction of the body 11. The flange portion 12 has a shape convex in the radial direction of the body 11. A pair of flat surfaces 12a, 12b parallel to each other are formed on the flange portion 12.

[0022] A center hole 20 is formed inside the body 11. The center hole 20 extends in the direction along the axis X1 of the body 11 from the base 11a of the body 11 toward the end face 11c. The center hole 20 includes a cylindrical inner surface 20a and a substantially conical tip-side inner surface 20b formed on the tip side of the cylindrical inner surface 20a.

[0023] The cylindrical inner surface 20a opens to the base 11a of the body 11. The diameter of the cylindrical inner surface 20a is constant in the direction along the axis X1. The tip-side inner surface 20b is formed inside the tip portion 11b of the body 11. The tip-side inner surface 20b opens to the end face 11c of the body 11. A punching portion 30 (enlarged and shown in FIG. 4) is formed on the tip portion 11b of the body 11. The punching portion 30 includes, for example, four punch portions 31, 32, 33, 34. The number of punch portions may be other than four.

[0024] A plurality of locations (for example, four locations) in the circumferential direction of the body 11 are formed with slits 41, 42, 43, 44. The slits 41, 42, 43, 44 constitute a slit portion 40. The slits 41, 42, 43, 44 each open to the outer surface and the inner surface of the body 11 and extend in a direction along the axis X1. These slits 41, 42, 43, 44 are each formed from the end face 11c of the body 11 to a position L2 (shown in FIGS. 1 and 2) in the middle of the length direction of the body 11. A circular hole 45 is formed at the position L2 in the middle of the length direction of the body 11 to prevent stress concentration at the ends of the slits 41, 42, 43, 44 or to reduce stress. The number of slits may be 4 or less or 4 or more.

[0025] As shown in FIG. 3, when the number of slits is 4, the slits 41, 42, 43, 44 are formed at equal intervals of 90° in the circumferential direction of the body 11. A first chuck element 51 is formed between the first slit 41 and the second slit 42. A second chuck element 52 is formed between the second slit 42 and the third slit 43. A third chuck element 53 is formed between the third slit 43 and the fourth slit 44. A fourth chuck element 54 is formed between the fourth slit 44 and the first slit 41. These chuck elements 51, 52, 53, 54 constitute a chuck portion 50. The number of chuck elements may be 4 or less or 4 or more.

[0026] Figure 4 is a plan view showing an enlarged view of the punching section 30. Convex punch portions 31, 32, 33, and 34 are formed at the respective tips of the chuck elements 51, 52, 53, and 54. The punch portions 31, 32, 33, and 34 protrude inside the body 11. An opening 55 for inserting the workpiece is formed between the punch portions 31, 32, 33, and 34 facing each other. The opening 55 is located on the axis X1 of the body 11. The punch portions 31, 32, 33, and 34 may be formed at positions other than the tip portion 11b of the body 11. In short, the punch portions 31, 32, 33, and 34 are formed on the inner surface facing the center holes 20 of the chuck elements 51, 52, 53, and 54 at any position in the direction along the axis X1. Moreover, the punch portions 31, 32, 33, and 34 protrude in directions facing each other.

[0027] Each of the chuck elements 51, 52, 53, and 54 can be elastically deformed slightly in the radial direction of the body 11 from the slit start position L2 (shown in FIGS. 1 and 2) in the middle of the length direction of the body 11 to the punch portions 31, 32, 33, and 34. That is, each of the chuck elements 51, 52, 53, and 54 can be elastically deformed in the direction in which the punch portions 31, 32, 33, and 34 approach each other. When the chuck elements 51, 52, 53, and 54 are elastically deformed in the radial direction of the body 11 with the slit start position L2 as a fulcrum, the size of the opening 55 changes. The punch portions 31, 32, 33, and 34 face the opening 55.

[0028] Figure 5 shows a part of the workpiece W before forming the caulked portion. An example of the workpiece W is a composite member composed of a first component W1 and a second component W2. The first component W1 is made of metal and has a cylindrical shape. A part of the length direction of the second component W2 is inserted into the first component W1. A positioning collar portion W3 may be formed on the first component W1, and a recess W4 may be formed on the second component W2.

[0029] FIG. 6 is a cross-sectional view showing the punching section 30 shown in FIG. 4 and the workpiece W1 before the clamping section is formed. The punching section 30 shown in FIG. 6 is in a state where the opening 55 is widened (referred to as the open position). The workpiece W is disposed at the center of the opening 55.

[0030] FIG. 7 shows a state where the punching section 30 has moved in the closing direction. FIG. 8 is a side view showing a part of the workpiece W in which the clamping section W5 is formed. A part of the first component W1 is pressed by the punch parts 31, 32, 33, 34 and plastically deformed in the recessed direction, whereby the clamping section W5 is formed. By this clamping section W5, the first component W1 and the second component W2 are fixed to each other.

[0031] FIG. 9 shows a cross-section of the mold set 60 including the clamping jig 10. FIG. 10 is a perspective view showing a part of the mold set 60. As shown in FIG. 9, the mold set 60 includes a base member 61, a lower mold 62 placed on the base member 61, a workpiece support member 63, a movable mold 64, a pressing member 65, and the like. A recess 66 into which the flange portion 12 of the clamping jig 10 is fitted is formed in the lower mold 62. The clamping jig 10 is supported in a substantially vertical posture by the lower mold 62.

[0032] The workpiece support member 63 has a shape (cylindrical shape) that can be inserted into the center hole 20 of the clamping jig 10. The workpiece support member 63 is inserted into the center hole 20 of the body 11. A workpiece holding portion 70 including a hole extending in the direction along the axis X1 is formed at the upper end of the workpiece support member 63. The workpiece holding portion 70 is located on the axis X1. By the workpiece holding portion 70, the workpiece W is held on the axis X1 in a vertically standing posture. The workpiece W held by the workpiece support member 63 protrudes upward from the opening 55 of the punching section 30.

[0033] The movable die 64 is disposed in a guide portion 71 formed in the lower die 62 so as to be movable in the vertical direction. The movable die 64 is biased upward by a biasing member 75 such as a spring. A load receiving portion 76 is formed in the movable die 64. The pressing member 65 moves the movable die 64 in a direction along the axis X1.

[0034] As shown in FIGS. 9 and 10, a hole 80 is formed in the movable die 64. A cam surface 81 is formed on the inner periphery of the hole 80. The tip portion 11b of the body 11 is inserted into the hole 80 of the movable die 64. In a state where the tip portion 11b is inserted into the hole 80, the tapered surface 13 of the clamping jig 10 is in contact with the cam surface 81. The cam surface 81 forms a second angle θ2 with respect to a virtual line segment L3 (shown in FIG. 9) parallel to the axis X1. The second angle θ2 corresponds to the first angle θ1 (shown in FIG. 2) of the tapered surface 13.

[0035] FIG. 9 shows a state where the movable die 64 and the pressing member 65 are in an elevated position. At this time, the punching portion 30 of the clamping jig 10 is in the open position shown in FIG. 6. The workpiece W held by the workpiece support member 63 is disposed in the opening 55 of the punching portion 30.

[0036] When the pressing member 65 is moved downward by a drive source, the movable die 64 is pressed by the pressing member 65 and moves downward. When the movable die 64 moves downward, the cam surface 81 of the movable die moves downward. The clamping jig 10 remains stationary. Therefore, when the cam surface 81 moves downward, the cam surface 81 presses in the radial direction of the body 11 while sliding along the axis X1 on the tapered surface 13. Thus, the punch portions 31, 32, 33, 34 move in a direction in which the opening 55 becomes smaller.

[0037] When the punch portions 31, 32, 33, 34 move in a closing direction, as shown in FIG. 7, the first component W1 is pushed by the punch portions 31, 32, 33, 34 and undergoes plastic deformation. Thereby, the clamping portion W5 is formed.

[0038] When the pressing member 65 moves upward, the movable die 64 also moves upward. When the movable die 64 moves upward, the cam surface 81 of the movable die moves upward, and the cam surface 81 relatively rises with respect to the tapered surface 13. When the cam surface 81 rises, due to the elastic restoring force of the chuck elements 51, 52, 53, 54, the punch parts 31, 32, 33, 34 move in the direction in which the opening 55 becomes larger. As a result, the opening 55 becomes larger, and the punch parts 31, 32, 33, 34 move away from the workpiece W, so that the workpiece W can be taken out from the opening 55.

[0039] According to the mold set 60 of the present embodiment, by moving the movable die 64 in the direction along the axis X1 with respect to the clamping jig 10, all the chuck elements 51, 52, 53, 54 can be simultaneously moved in the radial direction of the body 11 by the cam surface 81. For this reason, the workpiece W can be simultaneously pressed radially from the outside by the punch parts 31, 32, 33, 34. Therefore, a plurality of clamping parts W5 are simultaneously formed at equal intervals at a plurality of locations in the circumferential direction of the workpiece W. Moreover, the thickness of the punch parts 31, 32, 33, 34 (the thickness T2 shown in FIG. 12(C)) can be made sufficiently small. For this reason, even a small workpiece can be clamped without problems.

[0040] An example of the manufacturing method of the clamping jig 10 will be described below with reference to FIGS. 11 and 12. FIG. 11(A) is a side view showing an intermediate product 90 as a material of the clamping jig 10. In this specification, a product in the middle of manufacturing the clamping jig 10 is referred to as an intermediate product 90. The intermediate product 90 shown in FIG. 11(A) has a solid body 11 and a flange portion 12.

[0041] As shown in FIG. 11(B), for example, a tapered surface 13 is formed at the tip of the intermediate product 90 by machining. Flat surfaces 12a and 12b are also formed on the flange portion 12. As shown in FIG. 11(C), for example, a slit portion 40 is formed in the intermediate product 90 by machining or wire electrical discharge machining. Further, a circular hole 45 is formed at the end of the slit portion 40.

[0042] As shown in FIG. 12(A), a center hole 20 is formed in the body 11 of the intermediate product 90. As an example of means for forming the center hole 20, an electric discharge machine 100 and an X-ray fluoroscopic apparatus 101 are used. The X-ray fluoroscopic apparatus 101 has an X-ray source 101a and a detector 101b. The center hole 20 is formed from the base 11a to the tip 11b of the body 11 by the electric discharge machine 100.

[0043] During electric discharge machining, the X-ray fluoroscopic apparatus 101 is used to check the distance from the tip 20c of the center hole 20 to the end face 11c of the body 11. While checking the distance from the tip 20c of the center hole 20 to the end face 11c of the body 11 by fluoroscopy with the X-ray fluoroscopic apparatus 101, electric discharge machining of the center hole 20 is performed. Thus, the thickness of the punch machining portion 30 can be accurately regulated.

[0044] As shown in FIG. 12(B), the punch machining portion 30 is machined by a machining machine 110, and punch portions 31, 32, 33, 34 (shown in FIG. 4 etc.) having a predetermined shape are formed. The machining machine 110 may be a machining by mechanical processing, but may be other machining.

[0045] As shown in FIG. 12(C), the base 11a of the body 11 is machined so that the thickness T1 of the flange portion 12 becomes a predetermined value. Also, the end face 11c of the body 11 is polished so that the distance T2 from the tip 20c of the center hole 20 to the end face 11c of the body 11 becomes a predetermined value. By using the X-ray fluoroscopic apparatus 101 during this machining, the distance T2 from the tip 20c of the center hole 20 to the end face 11c may be checked.

[0046] As described above, the manufacturing method of the present embodiment includes steps (1) to (5). (1) Perform machining of the flange portion 12 and the tapered surface 13 on the intermediate product 90 of the clamping jig. (2) Form a slit portion 40 and a circular hole 45 in the intermediate product 90. (3) The center hole 20 is formed by electrical discharge machining. At this time, an X-ray fluoroscope is used to confirm the position of the tip 20c of the center hole 20 by fluoroscopy. (4) The punching part 30 is machined into a predetermined shape. (5) The length of the intermediate product 90 is finished to a predetermined value by machining or the like. In particular, the end face 11c is machined so that the distance from the tip 20c of the center hole 20 to the end face 11c of the body 11 becomes a predetermined value.

[0047] FIG. 13 is a perspective view showing the clamping jig 10A according to the second embodiment. This clamping jig 10A has a substantially prismatic body 11A. A plurality of slits 41, 42, 43, 44 are formed in this body 11A in the same manner as in the first embodiment. The body 11A does not have the tapered surface 13 (shown in FIGS. 1 and 2 etc.) of the first embodiment. Since the other configurations are common to the first embodiment, the same reference numerals are given to the common parts of both, and the description thereof is omitted.

[0048] The tip portions 120 of the chuck elements 51, 52, 53, 54 of the body 11A are brought into contact with the cam surface (for example, the cam surface 81 shown in FIG. 9) of the mold set. Then, the chuck elements 51, 52, 53, 54 are driven in the direction indicated by the arrow Y in FIG. 13 by the cam surface. By doing so, the punch portions 31, 32, 33, 34 move in the closing direction, and the workpiece can be clamped. Note that the body 11A may have a shape other than a quadrangular prism, for example, a polygon such as a hexagon or an octagon in cross section. A tapered surface having an angle corresponding to the cam surface 81 may be formed on the outer surface of the end portion of the body 11A.

[0049] In practicing the present invention, each element constituting the mold set, including the shape and structure of the clamping jig, may be changed as necessary. The number of slits formed in the body and the number of punch portions may be other than 4 respectively. Further, the workpiece is not limited to a composite member composed of a plurality of parts, and may be a workpiece composed of one part.

Explanation of reference numerals

[0050] 10, 10A... clamping jig, 11... body, 11a... base portion, 11b... tip portion, 11c... end face, 12... flange portion, 13... tapered surface, 20... center hole, 20c... tip, 30... punching portion, 31, 32, 33, 34... punch portions, 40... slit portion, 41, 42, 43, 44... slits, 45... circular hole, 50... chuck portion, 51, 52, 53, 54... chuck elements, 55... opening, 60... die set, 61... base member, 62... lower die, 63... work support member, 64... movable die, 65... pressing member, 70... work holding portion, 81... cam surface, 90... intermediate product, 100... electric discharge machine, 101... X-ray fluoroscopy device, W... work, W1... first component, W2... second component.

Claims

1. A clamping jig for clamping a workpiece, comprising: a body; a center hole formed inside the body and extending in a direction along the axis of the body; a plurality of slits formed at a plurality of locations on the body, each opening to the outer surface and the inner surface of the body and extending in the direction along the axis; a plurality of chuck elements formed between the adjacent slits of the body; punch portions respectively formed on the inner surfaces of the plurality of chuck elements facing the center hole and protruding in directions facing each other; an opening for inserting the workpiece; The clamping jig is characterized by comprising the above components.

2. The clamping jig according to claim 1, wherein: The clamping jig has a tapered surface formed on the outer surface of the end of the body and having a width decreasing toward the end face of the body.

3. The clamping jig according to claim 1, wherein: The slits are formed from the end face of the body to a position in the middle of the length direction of the body, and each of the plurality of chuck elements is elastically deformable in a direction in which the punch portions approach each other.

4. A mold set comprising the clamping jig according to claim 1, comprising: a lower mold supporting the clamping jig; a movable mold having a hole into which the body is inserted and having a cam surface in contact with the body on the inner periphery of the hole; a pressing member for moving the movable mold in a direction along the axis with respect to the clamping jig; The mold set is characterized by comprising the above components.

5. The mold set according to claim 4, wherein: The mold set has a workpiece support member inserted into the center hole of the clamping jig, and the workpiece support portion has a workpiece holding portion for holding the workpiece in a state where the workpiece is inserted into the opening.

6. A manufacturing method for manufacturing the clamping jig according to claim 1, comprising: forming the plurality of slits in an intermediate product as the material of the clamping jig; forming the center hole in the intermediate product by electrical discharge machining; when forming the center hole by electrical discharge machining, using an X-ray fluoroscope to confirm the position of the tip of the center hole by fluoroscopy; machining the punch portions into a predetermined shape; machining the end face so that the distance from the tip of the center hole to the end face of the body becomes a predetermined value. The manufacturing method of the clamping jig is characterized by the above steps.

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