JP2009285659A - Press forming method and press die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a press forming method and a press die by which formation of burrs or the like is more reduced and highly accurate pressed parts are formed. <P>SOLUTION: By performing a roughly blanking step, a half-blanking step and a blanking step successively, a metal sheet 1 is blanked and a gear 2 is formed. In the roughly blanking step, the metal sheet 1 is blanked and a hole 12 encircling a parts forming portion 11 to be formed into the gear 2 on the metallic sheet 1 is formed. In the half-blanking step, the metal sheet 1 to which the roughly blanking step is applied is half-blanked and the parts forming portion 11 is projected and also a reduced sheet thickness portion 14 the sheet thickness of which is thinner than those of both these parts forming portion 11 and base material is formed over the entire circumference of the parts forming portion 11 between the outer peripheral part of the parts forming portion 11 and the base material. In the blanking step, the portion between the parts forming portion 11 and the reduced sheet thickness portion of the metal sheet 1 to which the half-blanking stage is applied is ruptured and the parts forming portion 11 is blanked from the metal sheet 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a press forming method and a press die for punching a plate-like member such as a metal plate to form a pressed part.

  Conventionally, various metal parts are formed by stamping a metal plate by a press forming method using a press die. The press die includes a pair of dies provided so as to be able to contact and separate from each other. One mold includes a punch, and the other mold includes a die having a hole through which the punch passes. A metal plate positioned between the pair of molds is punched to form a metal part.

  In such a press molding method, burrs or the like are easily formed on the processed surface of the metal part (the surface separated from the metal plate), and there are problems such as a decrease in accuracy of the pressed part as well as an appearance problem. It was.

  In order to solve such a problem, various press molding methods have been proposed (see, for example, Patent Documents 1 and 2). In the press forming method described in Patent Documents 1 and 2, a roughing process for punching a metal plate and forming a hole surrounding a part forming part formed into a metal part on the metal plate, and a roughing process were performed. A punching process for punching a part forming part from a metal plate is performed. Thus, by forming the hole surrounding the part forming part, the relief part of the metal plate at the time of the punching process is formed and the formation of burrs and the like is reduced.

  Moreover, as a conventional example of the press forming method described in Patent Document 2, a metal plate that has been subjected to a half punching process in which a metal plate is half punched to project a part that is slightly larger than the part forming portion, and a half punching process is performed. Describes a press forming method of performing a punching step of punching a part forming part from a metal plate while leaving a certain forming allowance from a half punching portion.

In another press forming method, the clearance (gap) between the punch and the die of the press die is reduced to increase the ratio of the sheared surface on the processed surface and reduce the formation of burrs and the like.
JP 2007-301594 A JP-A-63-5829

  However, the press forming method described in Patent Documents 1 and 2 and the press forming method that reduces the clearance between the punch and the die cannot sufficiently reduce the formation of burrs and the like on the processed surface depending on the shape of the metal part. was there.

  For example, in the case where the metal part is a gear, the manner of the action of stress at the time of punching differs between the tooth base and the tooth tip. Then, the entire processed surface becomes a sheared surface at the tooth base, but the metal plate is not completely broken, and a part of the sheared surface is stretched and protrudes to the outer surface side of the gear, and a burr is formed. Further, secondary shear occurs on the processed surface of the tooth tip. Furthermore, there is a problem that the accuracy of the gear is greatly reduced because the state of the processed surface is different between the tooth root and the tooth tip, that is, the outer peripheral surface of the gear is not uniform over the entire circumference.

  This invention makes it an example of a subject to cope with such a problem. An object of the present invention is to provide a press molding method and a press die capable of forming a highly accurate press part by further reducing the formation of burrs or the like, for example.

  In order to solve the problems and achieve the object, the press molding method of the present invention according to claim 1 is a press molding method in which a plate member is punched to form a pressed part, and the plate member is punched out. Forming a hole surrounding a part forming portion formed on the pressed part on the plate-like member, and semi-punching the plate-like member subjected to the roughening step to form the part And a part having a reduced thickness, which is thinner than both the part molding part and the base material, is provided over the entire circumference of the part molding part. A punching process for forming and punching the part molding part from the plate member by breaking between the part molding part and the thickness reducing part of the plate member subjected to the half punching process. And performing the process.

  According to a fourth aspect of the present invention, there is provided a press die according to a fourth aspect of the present invention, wherein the plate-like member is formed by punching a plate-like member positioned between a pair of dies that are detachable from each other. A first press die used in a roughing process for punching out a member to form a hole surrounding a part molding part molded in the pressed part on the plate-like member, and the roughing process is performed. Half-punching the plate-like member to project the component molding part, and the thickness reduction between the outer edge part of the component molding part and the base material is thinner than both the part molding part and the base material A second press mold used in a half punching process for forming a part over the entire circumference of the part molding part, and the part molding part and the plate thickness reduction of the plate member subjected to the half punching process. Between the plate member and the part A third press die used in a punching process for punching a molding part, and an outer diameter of a punch of the second press die is larger than an inner diameter of a hole of the third press die It is characterized by.

  Hereinafter, an embodiment of the present invention will be described. A press molding method according to an embodiment of the present invention includes a half punching step of projecting a part molding part and forming a sheet thickness reducing part over the entire circumference of the part molding part, and a part molding part and a sheet thickness reducing part. Therefore, a fracture surface is reliably formed on the outer peripheral surface (processed surface) of the pressed part, and the formation of burrs can be further reduced to form a highly accurate pressed part. Furthermore, the press molding conditions are the same over the entire outer peripheral surface of the pressed part, a shear surface is formed over the entire circumference on one side of the outer peripheral surface in the half punching process, and the other in the press direction of the outer peripheral surface in the punching process. A fracture surface is formed over the entire side. Therefore, the outer peripheral surface of the press part can be formed uniformly over the entire periphery, and a highly accurate press part can be formed.

  In addition, since the reduced thickness portion is broken, the force applied to the press die can be reduced to extend the life of the press die. Further, since the roughing process for forming the hole surrounding the part forming part is performed, the relief part of the metal plate is formed, and the subsequent processes can be performed more reliably.

  Moreover, the outer diameter of the punch of the press die used in the half punching step may be larger than the inner diameter of the hole through which the punch of the press die used in the punching step passes. In this case, the part forming portion is not punched in the half punching step, and the plate thickness reducing portion can be formed easily and reliably.

  Further, the press part may be a gear. In this case, the formation of burrs on the outer peripheral surface of the gear can be further reduced, and the press molding conditions are equal at the tooth tip and the tooth base of the gear tooth portion, and the tooth tip and the outer peripheral surface of the tooth base are uniform over the entire circumference. Therefore, a highly accurate gear can be formed.

  A press die according to an embodiment of the present invention includes a second press die used in a half punching process for projecting a part forming part and forming a reduced thickness part over the entire circumference of the part forming part. Since it has a third press die used in the punching process for breaking between the part forming part and the plate thickness reducing part, the fracture surface is surely formed on the outer peripheral surface of the pressed part, and the burr is formed. It is possible to form a highly accurate pressed part by further reducing the above. Furthermore, the press working conditions are equal over the entire outer periphery of the pressed part, a shear surface is formed over the entire circumference on one side of the outer peripheral surface in the half punching process, and the other in the press direction of the outer peripheral surface in the punching process. A fracture surface is formed over the entire side. Therefore, the outer peripheral surface of the press part can be formed uniformly over the entire periphery, and a highly accurate press part can be formed.

  Furthermore, since the plate thickness reducing portion is broken, the force applied to the press die can be reduced to extend the life of the press die. Further, since the roughing process for forming the hole surrounding the part forming part is performed, the relief part of the metal plate is formed, and the subsequent processes can be performed more reliably. Moreover, since the outer diameter of the punch of the second press die is larger than the inner diameter of the hole of the third press die, the part forming portion is not punched in the half punching process, and the thickness reduction portion can be simplified. And it can be formed reliably.

  Further, one of the first to third press dies may be integrally formed, and the other of the first to third press dies may be integrally formed. In this case, the press die becomes a progressive die, and the press parts can be efficiently formed to greatly improve the production efficiency.

  Further, the press part may be a gear. In this case, the formation of burrs on the outer peripheral surface of the gear can be further reduced, and the press molding conditions are equal at the tooth tip and the tooth base of the gear tooth portion, and the tooth tip and the outer peripheral surface of the tooth base are uniform over the entire circumference. Therefore, a highly accurate gear can be formed.

  An embodiment of the present invention will be described with reference to FIGS. A press molding method according to an embodiment of the present invention is a press molding method in which, for example, a metal plate 1 as a plate-like member is punched to form a gear (gear) 2 as a press part, as shown in FIG. is there. In this embodiment, the gear 2 will be described as an example of the press part. However, the press part may be a press part other than the gear 2, and the press molding method of the present invention is also applicable to other press parts. It is possible.

  The metal plate 1 is made of, for example, a metal material such as steel, stainless steel, aluminum, copper, titanium, or an alloy thereof, and is formed in a long strip shape as shown in FIG. In the present specification, the part formed on the gear 2 of the metal plate 1 (the part having the same shape as the gear 2) is used as the part forming part 11.

  As shown in FIG. 2, the gear 2 includes a disk-shaped main body portion 21, a plurality of tooth portions 22 protruding from the main body portion 21 toward the outside of the main body portion 21, and a shaft hole penetrating through the center of the main body portion 21. 23. As shown in FIG. 3, the gear 2 formed in the present embodiment has an outer peripheral surface on one side (front side) in the pressing direction P as a shear surface 2 a over the entire circumference, and the other in the pressing direction P ( The outer peripheral surface on the rear side is a fracture surface 2b.

  As shown in FIG. 4, the press device 3 includes a frame 30 as a device body, a press machine 4, a press die 5, and a supply mechanism (not shown). The frame 30 is installed on the floor of a factory or the like.

  The press machine 4 includes at least a slide 41, a bolster 42, and a contact / separation mechanism 43. The slide 41 is formed in a flat plate shape and is supported by the frame 30 so as to be movable along the vertical direction. The lower surface of the slide 41 is formed flat along the horizontal direction. The bolster 42 is formed in a flat plate shape and is fixed to the frame 30. The upper surface of the bolster 42 is formed flat along the horizontal direction. The bolster 42 is disposed below the slide 41.

  The contact / separation mechanism 43 is a mechanical type in this embodiment, and uses a crank mechanism. The contact / separation mechanism 43 may use another mechanism such as a hydraulic type. The contact / separation mechanism 43 moves the slide 41 along the vertical direction, that is, the press direction P (indicated by the arrow P). The contact / separation mechanism 43 moves the slide 41 along the pressing direction P to bring the slide 41 and the bolster 42 into contact with or away from each other (approach or move away).

  As shown in FIG. 5, the press die 5 is integrally provided with first to third press dies 51 to 53. The first to third press dies 51 to 53 are respectively used in a roughing process, a half punching process, and a punching process, which will be described later.

  As shown in FIGS. 5 and 6, the first press die 51 includes an upper die 61 and a lower die 71 which are provided so as to be able to come in contact with each other. The upper die 61 includes columnar punches 61a and 61b protruding along the pressing direction P.

  The punch 61 a is provided at the center of the upper die 61. The cross-sectional shape of the punch 61 a in the direction orthogonal to the pressing direction P is formed in a circular shape having substantially the same shape as the shaft hole 23. The punch 61b is formed so that the cross-sectional shape in a direction orthogonal to the pressing direction P is an annular shape having two openings, and the punch 61a is positioned inside. The punch 61b is formed so that the opening is opened at both ends in the width direction of the metal plate 1 to be press-formed. The inner diameter of the punch 61b is larger than the outer diameter of the component molding part 11 (gear 2).

  The lower mold 71 includes a die 81. The die 81 includes a round hole 81a formed along the pressing direction P and a hole 81b. The cross-sectional shape of the round hole 81a in the direction orthogonal to the pressing direction P is formed in a circular shape having substantially the same shape as the punch 61a. The cross-sectional shape of the hole 81b in the direction orthogonal to the pressing direction P is formed to be substantially the same shape as the punch 61b.

  In the first press die 51 described above, when the upper die 61 approaches the lower die 71, the punches 61a and 61b are respectively passed through the round holes 81a and 81b of the die 81 to punch out the metal plate 1. FIG. As shown in FIG. 6, the shaft hole 23 and the hole 12 of the gear 2 are formed.

  As shown in FIG. 1, the holes 12 are formed in an annular shape having openings that open at both ends in the width direction of the metal plate 1. The outer edge of the hole 12 is formed in an arc shape. The inner diameter of the hole 12 is larger than the outer diameter of the component molding part 11 (gear 2). The hole 12 is formed so as to surround the component molding part 11. The hole 12 serves as a relief portion of the metal plate 1 in a half punching process or a punching process. The hole 12 corresponds to the hole described in claim 1 of the claims. The shape of the hole 12 is not limited as long as the hole 12 is provided so as to surround the component forming portion 11. In addition to the holes 12, a relief portion that penetrates or is cut out from the metal plate 1 may be appropriately formed.

  As shown in FIGS. 5 and 7, the second press die 52 includes an upper die 62 and a lower die 72 which are provided so as to be able to contact and separate from each other. The upper die 62 includes a columnar punch 62 a that protrudes along the pressing direction P. The punch 62 a is provided at the center of the upper mold 62. The cross-sectional shape of the punch 62a in the direction orthogonal to the pressing direction P is formed in a gear shape larger than that of the component forming portion 11 (gear 2).

  The lower mold 72 includes a die 82. The die 82 includes a hole 82 a formed along the pressing direction P. The cross-sectional shape of the hole 82a in the direction perpendicular to the pressing direction P is smaller than the punch 62a and is formed in a gear shape having substantially the same shape as that of the component molding part 11. The hole 82a is arranged coaxially with the punch 62a.

  In the second press die 52 described above, when the upper die 62 approaches the lower die 72, the punch 62 a is arranged so as to cover the hole 82 a of the die 82, thereby forming the recess 13 in the metal plate 1. As shown in FIG. 7, the recess 13 is formed as a recess from the outer surface of the metal plate 1 on the punch 62 a side. As shown in FIG. 1, the recess 13 is formed in a gear shape larger than the component molding portion 11 (gear 2) and is formed concentrically with the component molding portion 11. By forming the concave portion 13, the component forming portion 11 protrudes toward the hole 82 a side and is half-punched, and the plate thickness reducing portion 14 is formed. The plate thickness reducing portion 14 is formed over the entire periphery of the component molding portion 11 between the outer edge portion of the component molding portion 11 and the base material. The plate thickness reducing portion 14 is thinner than both the component forming portion 11 and the base material.

  As shown in FIGS. 5 and 8, the third press die 53 includes an upper die 63 and a lower die 73 that are provided so as to be able to contact and separate from each other. The upper die 63 includes a columnar punch 63 a that protrudes along the pressing direction P. The cross-sectional shape of the punch 63a in the direction orthogonal to the pressing direction P is formed in a gear shape substantially equal to that of the component forming portion 11 (gear 2).

  The lower mold 73 includes a die 83. The die 83 includes a hole 83a formed along the pressing direction P. The cross-sectional shape of the hole 83a in the direction orthogonal to the pressing direction P is formed in a gear shape having substantially the same shape as the punch 63a (that is, the component forming portion 11 and the gear 2). That is, the outer diameter of the punch 62a of the second press die 52 described above is larger than the inner diameter of the hole 83a.

  In the third press die 53 described above, when the upper die 63 approaches the lower die 73, the punch 63 a is passed through the hole 83 a and punches the component forming part 11 from the metal plate 1.

  As shown in FIG. 5, the upper dies 61 to 63 of the first to third press dies 51 to 53 described above follow the movement direction M of the metal plate 1 from the upstream to the downstream in the movement direction M. They are provided side by side and are integrally formed as the upper die 6. The upper mold 6 is fixed to the lower surface of the slide 41 and is disposed above the movement path of the metal plate 1. Each of the upper dies 61 to 63 corresponds to one of the dies described in the claims.

  Further, the lower dies 71 to 73 of the first to third press dies 51 to 53 are provided side by side along the movement direction M of the metal plate 1 from the upstream side to the downstream side of the movement direction M. The mold 7 is integrally formed. The lower mold 7 is fixed to the upper surface of the bolster 42 and is disposed below the movement path of the metal plate 1. Each of the lower molds 71 to 73 corresponds to the other mold described in the claims.

  The press die 5 described above is attached to the press machine 4 so that the upper dies 61 to 63 are opposed to the lower dies 71 to 73 along the pressing direction P, respectively. The metal plate 1 is positioned between the upper mold 6 and the lower mold 7. When the slide 41 and the bolster 42 contact and separate from each other by the contact / separation mechanism 43, the upper mold 6 fixed to the slide 41 and the lower mold 7 fixed to the bolster 42 are brought into contact with and separated from each other, and the upper molds 61 to 63 are The lower molds 71 to 73 are contacted and separated simultaneously. Thus, the press die 5 described above is a progressive die.

  The supply mechanism includes, for example, a pair of rollers and a drive unit that rotationally drives the rollers. The pair of rollers are rotatably supported and position the metal plate 1 between them. When the upper mold 6 and the lower mold 7 are separated from each other, the driving unit intermittently rotates the roller by a certain angle. In the supply mechanism, the drive unit rotates the roller as described above to move the metal plate 1 intermittently by one pitch (a constant distance) in the direction of the arrow M along the longitudinal direction of the metal plate 1, The metal plate 1 is supplied between the upper mold 6 and the lower mold 7.

  As shown in FIGS. 1 and 5, first to third press positions P <b> 1 to P <b> 3 are provided on the movement path of the metal plate 1 of the press device 3 described above. In the first to third press positions P1 to P3, a roughing process, a half punching process, and a punching process are performed, respectively. The first to third press positions P <b> 1 to P <b> 3 are provided side by side along the movement direction M of the metal plate 1 from upstream to downstream in the movement direction M. First to third press dies 51 to 53 are arranged at the first to third press positions P1 to P3, respectively. When the slide 41 and the bolster 42 contact and separate once, the roughing process, the half punching process, and the punching process are performed simultaneously at the press positions P1 to P3.

  When forming the gear 2 by punching the metal plate 1 using the press device 3 having the above-described configuration, first, the press machine 4 is operated to operate the slide 41 and the bolster 42, that is, the upper die 6 of the press die 5. The lower mold 7 is continuously contacted and separated. Further, the metal plate 1 is moved one pitch at a time along the moving direction M by the supply mechanism, and the metal plate 1 is supplied between the upper mold 6 and the lower mold 7.

  When the metal plate 1 is positioned at the first press position P1, a roughing process is performed as shown in FIG. As the slide 41 approaches the bolster 42, the punches 61 a and 61 b of the first press die 51 descend with pressure in the round holes 81 a and 81 b of the die 81, respectively, and punch the metal plate 1. Thus, the shaft hole 23 and the hole 12 are formed in the metal plate 1. Thereafter, the slide 41 moves away from the bolster 42.

  And the metal plate 1 moves 1 pitch, and as shown in FIG. 7, the part which performed the roughing process of the metal plate 1 is positioned in the 2nd press position P2, and a half punching process is performed. The slide 41 approaches the bolster 42, and the punch 62 a of the second press die 52 is lowered toward the hole 82 a of the die 82 with a pressure to form the recess 13 in the metal plate 1.

  When the recess 13 is formed, a part of the metal plate 1 is sheared and the part forming part 11 is half-punched, and a part of the part forming part 11 protrudes into the hole 82a. A shear surface (that is, the shear surface 2a of the gear 2) is formed over the entire outer peripheral surface of the protruding portion of the component molding portion 11. When the recess 13 is formed, the portion sandwiched between the inner edge of the front end surface of the punch 62a and the outer edge of the hole 82a is compressed, and the plate thickness reducing portion 14 is formed on the metal plate 1. Thereafter, the slide 41 moves away from the bolster 42.

  Then, the metal plate 1 is further moved by one pitch, and as shown in FIGS. 8 and 9, the part of the metal plate 1 that has been completed up to the half punching process is positioned at the third press position P3, and the punching process is performed. Is called. The slide 41 approaches the bolster 42, and the punch 63 a of the third press die 53 descends into the hole 83 a of the die 83 with pressure and moves between the component forming portion 11 and the plate thickness reducing portion 14. The part forming part 11 is punched out from the metal plate 1 by breaking. At this time, a fracture surface (that is, the fracture surface 2 b of the gear 2) is formed over the entire outer peripheral surface of the part molding portion 11 that is connected to the plate thickness reducing portion 14. As described above, the metal plate 1 is punched to form the gear 2.

  According to the present embodiment, the fracture surface 2b is reliably formed on the outer peripheral surface of the gear 2, and the formation of a burr can be further reduced to form the gear 2 with high accuracy. Furthermore, since the press molding conditions can be made equal to each other at the tooth tip 22 and the tooth root of the tooth portion 22 of the gear 2, the outer peripheral surface of the gear 2 can be formed uniformly over the entire circumference, and the highly accurate gear 2 can be molded. Moreover, since the plate | board thickness reduction | decrease part 14 is fractured | ruptured, the force applied to the press die 5 can be made small, and the lifetime of the press die 5 can be prolonged. Moreover, since the roughing process which forms the hole 12 surrounding the component shaping | molding part 11 is performed, the escape part of the metal plate 1 is formed and a subsequent process can be performed more reliably.

  Further, the outer diameter of the punch 62a of the press die 5 used in the half punching step is larger than the inner diameter of the hole 83a through which the punch 63a of the press die 5 used in the punching step is passed. Therefore, the part forming portion 11 is not punched in the half punching process, and the thickness reducing portion 14 can be easily and reliably formed.

  Further, the upper dies 61 to 63 of the first to third press dies 51 to 53 are integrally formed, and the lower dies 71 to 73 of the first to third press dies 51 to 53 are integrally formed. Yes. Therefore, the press die 5 becomes a progressive die, and the gear 2 can be efficiently molded to greatly improve the production efficiency.

  In the present embodiment, the first to third press dies 51 to 53 are integrally formed. However, although the production efficiency of the gear 2 is reduced, it is not necessarily formed integrally. In the present embodiment, the shaft hole 23 of the gear 2 is formed in the roughing process, but it may be before or after the roughing process.

  In addition, the Example mentioned above only showed the typical form of this invention, and this invention is not limited to an Example. That is, various modifications can be made without departing from the scope of the present invention.

  According to the embodiment described above, the following press molding method and press mold 5 are obtained.

(Additional remark 1) It is the press molding method which stamps the metal plate 1 and shape | molds the gearwheel 2, Comprising:
A roughing step of punching the metal plate 1 to form a hole 12 surrounding the component forming part 11 formed on the gear 2 on the metal plate 1;
The metal plate 1 that has been subjected to the roughing process is half-punched to project the component molding portion 11 and between the component molding portion 11 and the base material between the outer edge portion of the component molding portion 11 and the base material. A half punching step of forming the thickness reduction portion 14 having a thickness smaller than both of the materials over the entire circumference of the component forming portion 11;
A punching step in which the part forming portion 11 and the plate thickness reducing portion 14 of the metal plate 1 subjected to the half punching step are broken to punch the component forming portion 11 from the metal plate 1; A press molding method characterized by being performed.

  According to Supplementary Note 1, the fracture surface 2b is reliably formed on the outer peripheral surface of the gear 2, and the formation of the burr can be further reduced to form the gear 2 with high accuracy. Furthermore, since the press molding conditions can be made equal to each other at the tooth tip 22 and the tooth root of the tooth portion 22 of the gear 2, the outer peripheral surface of the gear 2 can be formed uniformly over the entire circumference, and the highly accurate gear 2 can be molded. Moreover, since the plate | board thickness reduction | decrease part 14 is fractured | ruptured, the force applied to the press die 5 can be made small, and the lifetime of the press die 5 can be prolonged. Moreover, since the roughing process which forms the hole 12 surrounding the component shaping | molding part 11 is performed, the escape part of the metal plate 1 is formed and a subsequent process can be performed more reliably.

(Supplementary Note 2) In a press mold 5 for forming a gear 2 by punching out a metal plate 1 positioned between an upper mold 6 and a lower mold 7 provided so as to be able to come into contact with each other.
A first press die 51 used in a roughing process for punching the metal plate 1 and forming a hole 12 surrounding the component forming part 11 formed on the gear 2 on the metal plate 1;
The metal plate 1 that has been subjected to the roughing process is half-punched to project the component molding portion 11, and between the outer edge portion of the component molding portion 11 and the base material, A second press die 52 used in a half punching process for forming the thickness reduction portion 14 having a thickness smaller than both of the materials over the entire circumference of the component molding portion 11;
It is used in a punching process in which the part forming part 11 and the plate thickness reducing part 14 of the metal plate 1 subjected to the half punching process are broken to punch the part forming part 11 from the metal plate 1. A third press die 53, and
The press die 5, wherein the outer diameter of the punch 62 a of the second press die 52 is larger than the inner diameter of the hole 83 a of the third press die 53.

  According to Supplementary Note 2, the fracture surface 2b is reliably formed on the outer peripheral surface of the gear 2, and the formation of a burr can be further reduced to form the gear 2 with high accuracy. Furthermore, since the press molding conditions are equal between the tooth tip 22 and the tooth root of the tooth portion 22 of the gear 2, the outer peripheral surface of the gear 2 can be formed uniformly over the entire circumference, and the gear 2 with high accuracy can be molded. Moreover, since the plate | board thickness reduction | decrease part 14 is fractured | ruptured, the force applied to the press die 5 can be made small, and the lifetime of the press die 5 can be prolonged. Moreover, since the roughing process which forms the hole 12 surrounding the component shaping | molding part 11 is performed, the escape part of the metal plate 1 is formed and a subsequent process can be performed more reliably. Further, the part forming portion 11 is not punched in the half punching process, and the thickness reducing portion 14 can be easily and reliably formed.

It is explanatory drawing which shows the press molding method concerning one Example of this invention. It is a front view which shows the gearwheel shape | molded with the press molding method shown by FIG. It is sectional drawing along the III-III line in FIG. It is explanatory drawing which shows the structure of the press apparatus used with the press molding method shown by FIG. It is sectional drawing which shows the press metal mold | die of the press apparatus shown by FIG. FIG. 6 is a cross-sectional view illustrating a state after a roughing process is performed on the metal plate illustrated in FIG. 5. It is sectional drawing which shows the state after a half punching process was performed to the metal plate shown by FIG. It is sectional drawing which shows the state in which the punching process is performed to the metal plate shown by FIG. It is sectional drawing which shows the state after the punching process was performed to the metal plate shown by FIG.

Explanation of symbols

1 Metal plate (plate member)
2 Gears (press parts)
DESCRIPTION OF SYMBOLS 11 Component shaping | molding part 12 Hole 14 Plate | board thickness reduction | decrease part 51 1st press die 52 2nd press die 53 3rd press die 61 Upper die (one type | mold of 1st press die)
62 Upper die (one die of the second press die)
62a Punch 63 Upper die (One die of the third press die)
63a Punch 71 Lower mold (the other mold of the first press mold)
72 Lower mold (the other mold of the second press mold)
73 Lower mold (the other mold of the third press mold)
83a hole

Claims (6)

A press molding method for punching a plate-like member and molding a pressed part,
A roughing step of punching the plate-like member and forming a hole surrounding a component molding portion to be molded into the pressed part on the plate-like member;
The plate-shaped member that has been subjected to the roughing process is half-punched to project the component molding portion, and both the component molding portion and the base material are provided between the outer edge portion of the component molding portion and the base material. A half punching step of forming a plate thickness reduced portion having a thinner plate thickness over the entire circumference of the component molded portion;
Performing a punching step of puncturing the component molding portion from the plate-like member by breaking between the component molding portion and the plate thickness reducing portion of the plate-like member subjected to the half-punching step. A press forming method characterized.   2. The press according to claim 1, wherein an outer diameter of a punch of a press die used in the half punching step is larger than an inner diameter of a hole through which the punch of the press die used in the punching step is passed. Molding method.   The press molding method according to claim 1, wherein the press part is a gear. In a press die for forming a press part by punching a plate-like member positioned between a pair of dies provided so as to be able to come in contact with each other,
A first press die used in a roughing step for punching the plate-like member and forming a hole surrounding a part molding part to be molded into the press part on the plate-like member;
The plate-shaped member that has been subjected to the roughing process is half-punched to project the component molding portion, and both the component molding portion and the base material are provided between the outer edge portion of the component molding portion and the base material. A second press die used in a half punching step of forming a plate thickness reduced portion having a thinner plate thickness over the entire circumference of the component forming portion;
A third step used in a punching process in which the part forming portion of the plate-like member subjected to the semi-punching step and the plate thickness reducing portion are broken to punch out the component forming portion from the plate-like member. A press die, and
A press die, wherein an outer diameter of a punch of the second press die is larger than an inner diameter of a hole of the third press die. One mold of the first press mold, one mold of the second press mold, and one mold of the third press mold are integrally formed; and
The other die of the first press die, the other die of the second press die, and the other die of the third press die are integrally formed. The press die according to claim 4.   The press die according to claim 4 or 5, wherein the press part is a gear.

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