JP4864485B2 - Mold for press machine - Google Patents

Description

  The present invention relates to a metal mold having holes punched out, and relates to a molding die for a press machine provided with a surface pressing punch for crushing burrs generated at the edges of the holes.

When a burr is generated at the edge of the hole punched by pressing, and this burr is located on the functional surface side of the product, it is necessary to crush the burr to finish it as designed. Therefore, after the hole punching process, the burrs are crushed by the surface pressing punch fixed to the press die. This face-punch punch has a generally cylindrical shape, a main body part housed in the mold, a smaller diameter than the main body part, and a restriction part that protrudes from the mold surface and can be inserted into a product hole And. When the restriction portion is inserted into the hole of the product, the burr is crushed by the corner surface at the boundary between the main body portion and the restriction portion in the surface pressing punch.
For press forming including a step of punching a hole in a metal product, for example, a technique disclosed in Patent Document 1 is known.
JP 2003-117619 A

  In a press die equipped with a surface pressing punch, if a slight pitch shift occurs in the hole punched into the product, the position of this hole and the surface pressing punch is slightly shifted, and the restricting portion is properly inserted into the hole. Will not be. As a result, the burr at the edge of the hole may not be crushed, and the restricting portion of the surface pressing punch is forcibly inserted into the hole of the product, leaving an indentation or the like on the inner peripheral surface of the hole.

  The present invention is intended to solve such a problem, and the purpose of the present invention is to accurately crush the burrs generated at the edge of the hole even when there is a slight pitch shift in the hole of the product. It is an object of the present invention to provide a press mold that can eliminate indentation and the like on the inner peripheral surface of a hole.

The present invention is for achieving the above object, and is configured as follows.
The invention according to claim 1 is directed to a product in which holes are punched out by press working in the previous step, and a surface pressing punch for crushing burrs generated at the edges of the holes, and this burr crushing is performed in parallel. A press die having an outer shape punch for forming an outer shape portion of a product by press working, wherein the surface pressing punch includes a main body portion that fits in a center hole of a predetermined die, A restricting portion that protrudes from the surface and can be inserted into a circular hole punched into the center of the product, and a pressing surface that presses the edge of the hole when the restricting portion is inserted into the hole of the product. . And the control part in the state inserted in the hole of a product is comprised so that the compression force which acts on a product with the press work by an external shape punch may be received. As a result, when the restricting portion of the surface pressing punch is inserted into the circular hole, the burr generated at the edge of the hole is pressed by the pressing surface to crush the burr, and in parallel with this, the outer shape of the product is formed by the outer shape punch. The part is set to be processed into a circle. Further, a gap is provided between the outer peripheral surface of the main body portion of the surface pressing punch and the inner peripheral surface of the center hole of the mold. The surface pressing punch is attached to the mold by a single stripper bolt inserted through the center of the surface pressing punch so that the surface pressing punch can move within a gap in the center hole of the mold.

  By making the surface pressing punch movable relative to the mold in this way, even if there is a slight pitch shift in the hole punched out in the product, the surface pressing punch follows the position of the hole, and its restriction part Is inserted into the hole appropriately and smoothly. As a result, burr crushing is accurately performed by the pressing surface of the surface pressing punch, and the occurrence of indentation or the like on the inner peripheral surface of the hole by forcibly inserting the restriction portion of the surface pressing punch into the hole is also eliminated. The product targeted in the present invention is a concept including a semi-finished product before completion.

The invention described in claim 2 is the molding die for a press machine described in claim 1, wherein an arc-shaped chamfer is provided at the tip of the restricting portion of the surface pressing punch.
Thereby, the control part of a surface pressing punch is inserted more smoothly with respect to the hole of a product.

  Invention of Claim 3 is a shaping | molding die for presses as described in Claim 1 or 2, Comprising: While a surface pressing punch has a through-hole connected over the main-body part and the control part, this through-hole On the other hand, a stripper bolt is inserted from the end face side of the restricting portion and tightened to the mold side.

  Thus, unlike the configuration in which the stripper bolt is inserted from the mold side and fastened to the surface pressing punch, the stripper bolt can be easily attached and detached during maintenance of the surface pressing punch.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
Embodiment 1
First, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a plan view showing a part of the press molding process. The material 10 shown in this drawing is a metal material that is continuous in a strip shape, and is intermittently fed in the direction of the arrow in the drawing on the mold of the press machine, and the circular products 12 are sequentially pressed.

  In the process P1 of FIG. 1, a hole 12a is punched in the center of the product 12 (semi-finished product). And in process P2, while the burr | flash produced on the edge of the hole 12a is crushed, the external part 12c of the product 12 is shape | molded. In step P3, the product 12 (finished product) is removed from the material 10 at the outer peripheral portion thereof.

  FIG. 2 is a plan view showing a mold for performing the press working in the process P1. 3 is a cross-sectional view in the direction of arrows AA in FIG. 4 is an enlarged cross-sectional view of a part of FIG. The configuration of the mold shown in these drawings is roughly divided into a punch 20, an outer shape punch 28, and a surface pressing punch 40.

  The punch 20 is for forming a part of the product 12 and is assembled and fixed to the outer punch 28. The outer punch 28 is a mold for pressing the outer portion 12 c of the product 12. The surface pressing punch 40 is assembled in the center hole 22 of the punch 20 to crush burrs generated at the edge of the hole 12a in the product 12.

  As apparent from FIG. 3, the punch 20 is fixed to the outer shape punch 28 by a bolt (not shown) with a spacer 24 interposed therebetween. The surface pressing punch 40 is attached to the outer punch 28 by a stripper bolt 50 with a spacer 48 interposed between the upper surface of the outer punch 28 in the center hole 22 of the punch 20. The stripper bolt 50 has a head portion 50b at one end of the shaft portion 50a and a male screw portion 50c at the other end. The head portion 50b has a larger diameter than the shaft portion 50a, and the male screw portion 50c has a smaller diameter than the shaft portion 50a.

Next, the shape and mounting structure of the surface pressing punch 40 will be described in more detail.
The surface pressing punch 40 has a cylindrical shape as a whole, and has a large-diameter main body portion 42 and a small-diameter regulating portion 43 protruding from the end surface thereof. The restricting portion 43 is set to have an outer diameter that can be inserted into the hole 12a of the product 12, and the tip of the restricting portion 43 is chamfered in an arc shape for smooth insertion into the hole 12a. Further, the outer periphery of the boundary between the end surface of the main body portion 42 and the restricting portion 43 is an arc-shaped pressing surface 44 for pressing the burr of the hole 12a in the product 12. The inside of the surface pressing punch 40 is a through hole 46 through which the stripper bolt 50 is inserted. The through hole 46 communicates from the lower end surface of the main body portion 42 to the distal end surface of the restricting portion 43.

  The punch 20 is one of the molds in the mold, and the main body portion 42 of the surface pressing punch 40 is incorporated into the center hole 22 in a state where the regulating portion 43 protrudes from the surface of the punch 20. A gap S1 is provided between the inner peripheral surface of the center hole 22 of the punch 20 and the outer peripheral surface of the main body portion 42 of the surface pressing punch 40 (FIG. 4). The stripper bolt 50 is inserted into the through hole 46 from the end face side of the restricting portion 43, and penetrates the spacer 48 and is fastened to the outer shape punch 28. The through hole 46 is composed of a large diameter portion 46a and a small diameter portion 46b (FIG. 4). The head portion 50b of the stripper bolt 50 is located in the large diameter portion 46a, and a part of the shaft portion 50a is located in the small diameter portion 46b. ing.

  The stripper bolt 50 has a male screw portion 50c screwed into the outer punch 28, and the end surface of the shaft portion 50a is pressed against the upper surface of the outer punch 28 (FIG. 3). Thereby, the surface pressing punch 40 is not fastened to the outer shape punch 28 side, but is positioned in a floating state by the stripper bolt 50. That is, gaps S2 and S3 are secured between the inner surface of the large diameter portion 46a of the through hole 46 and the outer surface of the head portion 50b of the stripper bolt 50 in the surface pressing punch 40, and the inner peripheral surface of the small diameter portion 46b of the through hole 46. A gap S4 is secured between the outer peripheral surface of the shaft portion 50a of the stripper bolt 50. Accordingly, the surface pressing punch 40 can freely move within the gap S <b> 1 within the center hole 22 of the punch 20.

  In the burr crushing process P1 shown in FIG. 1, as already described, the regulating portion 43 of the surface pressing punch 40 is inserted into the hole 12a of the product 12, and the burr in the hole 12a is crushed by the pressing surface 44. . At the same time, the outer shape portion 12 c of the product 12 is pressed by the outer shape punch 28. In addition, the compression force of the direction which goes to the hole 12a from the outer peripheral side acts on the product 12 with shaping | molding this external shape part 12c. The restricting portion 43 of the surface pressing punch 40 receives this compressive force, and the dimensional accuracy of the hole 12a is maintained.

  When there is a slight pitch shift in the hole 12a punched in the product 12 in the process P1 in FIG. 1, a deviation occurs between the hole 12a and the mold in the process P1. However, since the surface pressing punch 40 can move with respect to the center hole 22 of the punch 20, the surface pressing punch 40 follows the position of the hole 12a, and the restricting portion 43 is accurately inserted into the hole 12a. As a result, the burr generated at the edge of the hole 12a can be uniformly crushed by the pressing surface 44. Further, the restricting portion 43 of the surface pressing punch 40 is not forcibly inserted into the hole 12a of the product 12, and it is possible to prevent the inner surface of the hole 12a from becoming indented and the inner diameter thereof from becoming an irregular shape, The durability of the mold can also be improved.

Embodiment 2
Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 5 is a cross-sectional view showing a mold according to the second embodiment. In the second embodiment, a stripper bolt 50 for attaching the surface pressing punch 40 to the outer punch 28 is inserted from the lower surface side of the outer punch 28. That is, in the second embodiment, the direction in which the stripper bolt 50 is inserted is opposite to that in the first embodiment.

  The surface pressing punch 140 according to the second embodiment is similar to the surface pressing punch 40 according to the first embodiment. The main body portion 142 has a large diameter, the small diameter regulating portion 143 projects from the end surface thereof, and the pressure surface 144 for crushing burrs. And have. However, the surface pressing punch 140 does not require the through hole 46 in the surface pressing punch 40, and the entire shape is a columnar shape. The main body portion 142 of the surface pressing punch 140 is incorporated into the center hole 22 of the punch 20, and a gap S <b> 1 is provided between the inner peripheral surface of the center hole 22 and the outer peripheral surface of the main body portion 14242.

  The stripper bolt 50 is inserted through the outer punch 28 and the spacer 48, and the male screw portion 50 c is screwed into the main body portion 142 of the surface pressing punch 140. Therefore, the stripper bolt 50 and the surface pressing punch 140 are in a fixed relationship with each other. However, gaps are set between the shaft portion 50a of the stripper bolt 50 and the outer shape punch 28 and the spacer 48, and between the head portion 50b of the stripper bolt 50 and the outer shape punch 28, respectively. Thereby, the surface pressing punch 140 is not fastened to the outer shape punch 28 side and can be moved together with the stripper bolt 50 in the center hole 22 of the punch 20.

  In the second embodiment, since the stripper bolt 50 is inserted from the outer punch 28 side, it is necessary to disassemble the entire mold in order to remove the stripper bolt 50 when the surface pressing punch 140 is maintained, for example. . However, if this point is excluded, the through hole 46 in the surface pressing punch 40 of the first embodiment can be eliminated, and there is an advantage that the strength of the surface pressing punch 140 can be increased.

Plan view showing part of the press molding process Plan view showing mold for press working Sectional view in the direction of arrow AA in FIG. Sectional drawing which expanded and represented a part of FIG. Sectional drawing showing the shaping | molding die of Embodiment 2

Explanation of symbols

12 products 12a hole 20 punch (die)
40 Surface pressing punch 42 Main body portion 43 Restricting portion 44 Pressing surface 50 Stripper bolt S1 Crevice

Claims (3)

For products with holes punched out by the press process in the previous process, surface pressing punches for crushing burrs generated at the edges of the holes, and forming the outer shape of the product by pressing in parallel with this burr crushing A press mold having an outer shape punch for performing,
The surface pressing punch has a main body part that fits in the center hole of a predetermined mold, a restriction part that can be inserted into a circular hole that protrudes from the surface of the mold and is punched into the center part of the product, A pressing surface that presses the edge of the hole when inserted into the hole of the product, and the restricting portion in the state of being inserted into the hole of the product has a compressive force acting on the product along with the press working by the outer shape punch When the restricting portion of the surface pressing punch is inserted into the circular hole, the burr generated at the edge of the hole is pressed with the pressing surface to crush the burrs. The outer shape of the product is set to be processed into a circular shape by the outer shape punch, and a gap is provided between the outer peripheral surface of the main body portion and the inner peripheral surface of the center hole of the die in the surface pressing punch. The push punch has a gap in the center hole of the mold. Range said surface press one press molds attached to the mold by a stripper bolt which is inserted through the center of the punch to allow movable in. A molding die for a press machine according to claim 1,
A molding die for a press machine in which an arc-shaped chamfer is provided at the tip of a restriction portion in the surface pressing punch. A molding die for a press according to claim 1 or 2,
The surface pressing punch has a through hole that communicates with the main body portion and the restricting portion, and a molding die for a press machine in which a stripper bolt is inserted into the through hole from the end face side of the restricting portion and tightened to the mold side. .

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