JP2015020179A - Die and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die and a manufacturing method thereof, capable of surely separating a punching piece fixed to the tip of a punch from the punch.SOLUTION: A die 10 of the present invention is fixed by pressing down by a collar 15 by applying a sheet metal ring 20 to a step difference surface 13 formed by diametrically expanding the innermost part of a punch rushing-in hole 12 formed in a die body 11, and a punching piece W1 fixed to the tip of a punch P1 is held by a plurality of locking projection pieces 21 formed in an inner edge part of the sheet metal ring 20, and is separated from the punch P1. In the die 10, the sheet metal ring 20 is formed with a plurality of folding parts 22 for folding the plurality of locking projection pieces 21 toward the innermost side of the punch rushing-in hole 12 as they are positioned closer to a tip part in an unused state of not using the die 10, and the folding parts 22 extend in a straight line shape orthogonal to the radial direction of the sheet metal ring 20.

Description

  The present invention relates to a die and a manufacturing method thereof.

  As this type of die, there is known one in which a sheet metal ring is applied to a stepped portion formed by expanding the depth of a punch insertion hole formed in a die body and pressed by a collar. The die has a configuration in which a punched piece fixed to the tip of the punch is held and released from the punch by a plurality of locking protrusions formed on the inner edge of the sheet metal ring (see, for example, Patent Document 1). ).

Japanese Utility Model Publication No. 58-160625 (page 3, line 1 to line 18, FIGS. 2 and 3)

  By the way, in a conventional die, a plurality of locking protrusions provided in the sheet metal ring are arranged on the same plane perpendicular to the sheet thickness direction of the sheet metal ring in an unused state. A plurality of locking projections are folded back by contacting the punched piece with the inner edge of the sheet metal ring. Thereafter, the punching piece is held by the bent locking projection. It was.

  However, in the conventional die described above, it is difficult to apply the punched piece evenly to the plurality of locking protrusions, and the bending state of the locking protrusions varies. It was difficult to disengage.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a die capable of reliably removing the punched piece fixed to the tip of the punch from the punch and a method for manufacturing the die.

  In order to achieve the above object, a die according to the first aspect of the present invention is directed to a stepped surface formed by expanding the depth of a punch entry hole formed in a die body, and holding a sheet metal ring on the step surface to hold it with a collar. The die is used for the sheet metal ring in a die that holds the punched piece fixed to the tip of the punch by a plurality of locking protrusions formed on the inner edge of the sheet metal ring and separates it from the punch. In the unused state, a plurality of bent portions are formed so that the plurality of locking protrusions are bent toward the deep side of the punch insertion hole toward the tip portion, and the bent portions are orthogonal to the radial direction of the sheet metal ring. It is characterized by a linear extension.

  According to a second aspect of the present invention, in the die according to the first aspect, the both sides of the locking projection piece are formed in a straight line perpendicular to the bent portion and parallel to each other, and the both sides are equidistant from the both sides. The reference straight line extending in parallel with the sheet metal ring is characterized in that it passes through the center of the sheet metal ring.

  According to a third aspect of the present invention, there is provided a die manufacturing method in which a sheet metal ring is applied to a stepped surface formed by expanding the depth of a punch entry hole formed in a die body, and is fixed by pressing with a collar. A die manufacturing method for holding a punched piece fixed to a tip of a punch by a plurality of locking projections formed on an inner edge of the punch and releasing the punch from the punch, wherein the plurality of locking projections are connected to a sheet metal ring. The sheet metal ring is preliminarily bent to one side face in the sheet thickness direction of the sheet metal ring at a linear bent portion orthogonal to the radial direction of the sheet metal ring, and the sheet metal ring is fixed to the step surface.

  The invention of claim 4 is characterized in that, in the die manufacturing method of claim 3, the inner edge of the sheet metal ring is pressed with a pressing tool having a polygonal cross section to form a plurality of bent portions.

  According to the first aspect of the present invention, in the sheet metal ring, when the die is not used, the bending portion that bends the plurality of locking protrusions toward the deep side of the punch insertion hole toward the tip portion. The bent portion extends in a straight line perpendicular to the radial direction of the sheet metal ring. Further, as in the invention of claim 3, the die is formed by bending a plurality of locking protrusions in advance on one side of the sheet metal ring in the sheet thickness direction at the bent portion, and then dicing the sheet metal ring into the die. Manufactured by fixing to the stepped surface of the body. And, according to the die having such a sheet metal ring, the bending state of the locking projection piece can be arranged in advance when not in use, so that the punched piece fixed to the tip of the punch can be reliably removed from the punch. Can be withdrawn.

  Here, the locking protrusions may be fan-shaped so that both sides approach each other as they go from the base end portion to the distal end portion. The sides may be formed in a straight line that is orthogonal to the bent portion and parallel to each other, and a reference straight line that extends in parallel to both sides at a position equidistant from both sides passes through the center of the sheet metal ring. .

  According to the fourth aspect of the present invention, the inner edge of the sheet metal ring is pressed by a pressing tool having a polygonal cross section, so that the plurality of locking protrusions can be folded together and evenly bent.

Side sectional view of a die according to the present invention. Top view of sheet metal ring Side cross-sectional view of a die holding a punched piece Side view of mold for sheet metal ring processing Two-sided view showing the side and tip of the molding punch (A) Plan view of lower mold, (B) Cross section of XX section Plan view of sheet metal ring according to modification Plan view of sheet metal ring according to modification

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a die 10 according to the present embodiment is formed by assembling a sheet metal ring 20 and a collar 15 inside a die body 11 having a cylindrical structure.

  The die body 11 has a cylindrical shape with both ends open, with a punch insertion hole 16 having a circular cross section passing through the center. The die body 11 has a step surface 13 formed by expanding the depth of the punch insertion hole 16, a large diameter portion 14 extending downward from the step surface 13, and a punching hole 12 above the step surface 13. The punch entry hole 16 is formed by the stepped surface 13, the large diameter portion 14, and the punching hole 12. The step surface 13 is a flat surface orthogonal to the penetrating direction of the punch insertion hole 16 (hereinafter referred to as “the axial direction of the die body 11” as appropriate). Further, the inside diameters of the punching hole 12 and the large diameter hole 14 are constant.

  A collar 15 is assembled inside the large diameter hole 14. The collar 15 has, for example, a cylindrical shape and is fitted inside the large-diameter hole 14. Further, the inner diameter of the collar 15 is larger than the inner diameter of the punching hole 12. The collar 15 is fixed to the inner peripheral surface of the die body 11 with an adhesive, for example.

  The sheet metal ring 20 is addressed to the step surface 13 of the die body 11, and the portion near the outer edge of the sheet metal ring 20 is sandwiched between the step surface 13 and the collar 15, so that the sheet metal ring 20 Movement in the axial direction is prohibited. The sheet metal ring 20 is prohibited from moving in the radial direction by the inner peripheral surface of the large-diameter hole 14. The inner diameter of the sheet metal ring 20 is smaller than the inner diameter of the punching hole 12 (more specifically, the outer diameter of the punched piece W1 punched by the punch P1). In addition, the sheet-metal ring 20 of this embodiment is made of stainless steel (SUS304), for example, and the plate thickness is 0.05 to 0.2 [mm].

  As shown in FIG. 2, the inner edge of the sheet metal ring 20 is equally divided into a plurality (specifically, for example, eight) of locking protrusions 21 in the circumferential direction. Specifically, the sheet metal ring 20 is formed with a plurality of bent portions 22 that extend in a straight line perpendicular to the radial direction of the sheet metal ring 20 in an unused state where the die 10 is not used for punching. The plurality of locking protrusions 21 are bent at one side in the plate thickness direction of the sheet metal ring 20 (direction perpendicular to the paper surface of FIG. 2) at the bent portions 22. Specifically, as shown in FIG. 1, the plurality of locking projections 21 are bent obliquely downward so as to go to the back side of the punch insertion hole 16 toward the tip. The bent portion 22 is formed on the radially outer side from the inner peripheral surface of the punching hole 12 and on the radially inner side from the inner peripheral surface of the collar 15.

  As shown in FIG. 2, trapezoidal cutout portions 23, 23 that are open toward the center of the sheet metal ring 20 are formed between the locking protrusions 21 adjacent to each other in the circumferential direction of the sheet metal ring 20. Has been. Thereby, both side sides 21A and 21A of each locking projection piece 21 are linearly orthogonal to the bent portion 22 and parallel to each other, and are parallel to both sides at positions equidistant from both side sides 21A and 21A. A reference straight line L1 extending in the direction of the sheet metal ring 20 is configured to pass through the center C1.

  In the die 10, a stepped surface of the die body 11 is inserted by inserting the sheet metal ring 20 in which the plurality of locking protrusions 21 are bent in one direction in the plate thickness direction into the large-diameter hole 14 of the die body 11 as described above. 13 is fixed by fixing the collar 15 in a state where the sheet metal ring 20 is sandwiched between the collar 15 inserted into the large-diameter hole 14 and the step surface 13.

  Further, the plurality of locking protrusions 21 formed on the sheet metal ring 20 are bent by a molding die 30 for sheet metal ring processing shown in FIGS. A circular positioning recess 32 is formed in the upper surface of the lower mold 31 of the molding die 30, and the center of the positioning recess 32 has a regular polygonal cross section penetrating the lower mold 31 in the vertical direction. A molding hole 33 is formed (see FIGS. 6A and 6B).

  On the other hand, the upper die 35 of the molding die 30 has a molding punch 36 (corresponding to the “pressing tool” of the present invention) having a regular polygonal cross section. A tapered surface 36 </ b> A is formed on the outer edge of the tip of the forming punch 36. A cylindrical pressing member 37 is attached to the outside of the forming punch 36. The pressing member 37 holds the sheet metal ring 20 between the bottom surface of the positioning recess 32 when the front end portion of the forming punch 36 enters the forming hole 33. The pressing member 37 is made of, for example, urethane rubber. In addition, the code | symbol 38 in FIG. 4 is a punch holder, and the code | symbol 39 is a shank.

  When bending the locking protrusion 21, first, the sheet metal ring 20 is fitted into the positioning recess 32 of the lower mold 31. At this time, the plurality of notches 23 and 23 formed on the inner edge of the sheet metal ring 20 are made to coincide with the corners of the forming hole 33 having a regular polygon shape. In this state, when the tip of the molding punch 36 is inserted into the molding hole 33, a plurality of bent portions 22 are formed on the sheet metal ring 20 between the outer edge of the tip of the molding punch 36 and the upper end opening edge of the molding hole 33. At the same time, the locking projections 21 are evenly bent by the bent portions 22 to one side in the plate thickness direction. This completes the sheet metal ring 20.

  Next, the operation of this embodiment will be described. The punched piece W1 punched by the punch P1 is pushed into the punch insertion hole 16 while being in sliding contact with the plurality of locking protrusions 21, and the punch P1 reaches the bottom dead center as shown in FIG. At that time, the front ends of the plurality of locking protrusions 21 are held against the side surface of the punched piece W1. When the punch P1 rises from the bottom dead center, the punched piece W1 held by the plurality of locking protrusions 21 is detached from the tip end portion of the punch P1.

  The punched piece W1 separated from the tip of the punch P1 is held by the sheet metal ring 20, but is pushed out by the punched piece W1 punched by the next punching operation. That is, every time the punching operation is performed, the old punched piece W1 one shot before held by the plurality of locking protrusions 21 is pushed by the new punched piece W1 immediately after being punched, and the sheet metal ring 20 passes through the inside of the collar 15, and a new punched piece W <b> 1 is held by the plurality of locking protrusions 21.

  Thus, according to this embodiment, the sheet metal ring 20 is formed with a plurality of bent portions 22 that extend in a straight line perpendicular to the radial direction of the sheet metal ring 20 in an unused state where the die 10 is not used. The plurality of locking protrusions 21 are bent in advance by the bending portion 22 so as to go to the back side of the punch insertion hole 16 toward the distal end portion. That is, the bending state of the plurality of locking protrusions 21 can be aligned in an unused state, and the punching piece W1 fixed to the tip of the punch P1 can be reliably detached from the punch P1. In addition, according to the manufacturing method of the present embodiment, the inner edge portion of the sheet metal ring 20 is pressed with the forming punch 36 having a polygonal cross section to form the plurality of bent portions 22, and thus the plurality of locking protrusions 21 are collected. Can be bent evenly.

  In order to investigate the effect of the present invention, a die 10 as an embodiment of the present invention having the same structure as that of the above embodiment is incorporated into a punch press machine (not shown), and a sheet metal (for example, a sheet thickness of 1. 6 [mm] SPCC material) is subjected to a punching test, the sheet metal ring 20 is taken out of the die 10 at a predetermined punching number (for example, 1000 times, 5000 times, and 10,000 times), and the holding state of the punched piece W1 is visually observed. confirmed. As a result, it was confirmed that the punched piece W1 was held by the sheet metal ring 20 (the plurality of locking protrusions 21) at any number of times of punching.

[Other Embodiments]
The present embodiment is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present embodiment, and further, within the scope not departing from the gist other than the following. Various modifications can be made.

(1) In the sheet metal ring 20 of the above-described embodiment, both sides 21A and 21A of the locking protrusion 21 are linearly orthogonal to the bent portion 22 and parallel to each other, but as shown in FIG. The both side sides 21 </ b> A and 21 </ b> A of the locking projection piece 21 may be configured to approach each other toward the center C <b> 1 of the sheet metal ring 20.

(2) Further, as shown in FIG. 8, a semicircular cutout portion 23 is formed at a plurality of positions on the inner edge of the sheet metal ring 20, and the portion is relatively convex with respect to the cutout portion 23. It is good also as a structure which used as the latching protrusion piece 21 and bent the base end part of these latching protrusion pieces 21 by the bending part 22 extended linearly orthogonal to the radial direction of the sheet-metal ring 20. FIG.

(3) In the present embodiment, the number of the locking protrusions 21 provided in the sheet metal ring 20 is eight, but the number of the locking protrusions 21 may be a plurality other than eight.

(4) In the above-described embodiment, the inner edge of the sheet metal ring 20 is pressed by the forming punch 36 for processing the sheet metal ring, and the plurality of locking protrusions 21 are bent together. 21 may be bent one by one.

DESCRIPTION OF SYMBOLS 10 Dies 11 Die body 12 Punching hole 13 Step surface 15 Collar 16 Punch entry hole 20 Sheet metal ring 21 Locking protrusion 21A Side of locking protrusion 22 Bending part 36 Molding punch (pressing tool)
C1 Sheet metal ring center L1 Reference straight line P1 Punch W1 Punched piece

Claims (4)

A plurality of locking protrusions formed on the inner edge of the sheet metal ring are fixed by pressing the sheet metal ring to a stepped surface formed by expanding the depth of the punch insertion hole formed in the die body and holding it with a collar. In the die for holding the punched piece fixed to the tip of the punch by the piece and separating it from the punch,
The sheet metal ring is formed with a plurality of bent portions for bending the plurality of locking protrusions toward the deeper side of the punch insertion hole toward the tip when the die is not used. ,
The die, wherein the bent portion extends in a straight line perpendicular to the radial direction of the sheet metal ring.   Both sides of the locking protrusion are formed in a straight line perpendicular to the bent portion and parallel to each other, and a reference straight line extending in parallel to the both sides at a position equidistant from the both sides is provided on the sheet metal ring. The die according to claim 1, wherein the die is configured to pass through the center. A plurality of locking protrusions formed on the inner edge of the sheet metal ring are fixed by pressing the sheet metal ring to a stepped surface formed by expanding the depth of the punch insertion hole formed in the die body and holding it with a collar. A die manufacturing method for holding a punched piece fixed to the tip of the punch by a piece and separating it from the punch,
The plurality of locking protrusions are pre-bent to one side of the sheet metal ring in the sheet thickness direction at a linear bent portion orthogonal to the radial direction of the sheet metal ring, and then the sheet metal ring is moved to the stepped surface. A die manufacturing method, characterized by being fixed to a die.   The die manufacturing method according to claim 3, wherein the plurality of bent portions are formed by pressing an inner edge portion of the sheet metal ring with a pressing tool having a polygonal cross section.

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