JPH1177176A - Method for embossment forming and die therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an embossment formed part free from necking and cracking by using the die for the embossment forming, which forms the embossment on a sheet shaped work. SOLUTION: An embossment forming part has a punch 3 having a groove shaped recessed forming surface 7 on its lower part, which is formed by enlarging a groove width in the vicinity of both ends of the punch 3 in a sectorial shape, and a projecting forming surface 19 corresponding to the vicinity of the center of the recessed forming surface 7. And, the die 5 having a circular-arc shaped forming surface 23 projected by being energized upward from this projecting forming surface 19, is made to cooperate with the punch 3 and the projecting forming surface 19. By a process (A) performing the forming of a circular-arc shaped forming part to a work in cooperation with the recessed forming surface 7 of the punch 3 and the circular-arc shaped forming surface 23 of the die 5 and (B) a process performing the forming of the embossment forming part by deforming above circular-arc shaped forming part in cooperation with the recessed forming surface 7 of the punch 3 and the projecting forming surface 19 of the die 5, the embossment forming is performed to a sheet shaped work W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an embossing method and an embossing die for forming an appropriate shape on a plate-like work using a press machine.

[0002]

2. Description of the Related Art A conventional embossing mold 101 is shown in FIG.
As shown in FIG.
The punch 103 is struck by a striker (not shown) from above in FIG. 4 and moves in the vertical direction. In the center of the lower part of the punch 103, a groove-shaped concave molding surface 107 in which the groove width near both ends is enlarged in a divergent manner is provided. The ejector 109 is provided above the die 105 by being urged by the spring 111. The upper limit of the movement of the ejector 109 is usually the die 10
5 is set at a position where the upper end thereof is almost the same height as the upper surface 109a of the ejector 109. The concave molding surface 1
07 at the position of the die 105 corresponding to the convex molding surface 113.
Is provided, and a hole 1 formed in the ejector 109 is provided.
15, the upper surface of the convex molding surface 113 and the upper surface of the ejector 109 are flush with each other.

In FIG. 4, a work W is inserted and is placed in contact with an upper surface 109a of an ejector 109. When the punch 103 is hit by the striker and descends, the lower surface 103 a and the upper surface 1 of the ejector 109
09a is interposed between the workpiece W and the workpiece W.

When the punch 103 further descends as shown in FIG.
And lowers while being sandwiched between the upper surface 109a of the ejector 109 and the ejector 109.
The workpiece W descends against the urging force of 11 and starts to come into contact with the convex forming surface 113 of the die 105 at the center of the work W, and plastic deformation starts from the first contact portion, and the forming proceeds.

FIG. 6 shows a state in which molding has been completed. The ejector 109 further descends against the urging force of the spring 111, and the lower surface 109a of the ejector 109 is
The workpiece W is stopped in contact with the surface 05, and the work W is embossed on the concave forming surface 107 of the punch 103 and the convex forming surface 113 of the die 105.

[0006]

In the above-described conventional embossing mold, as shown in FIGS. 7A, 7B and 7C, the elongation concentrates on the shoulder 117 of the product. For this reason, there is a disadvantage that the constriction 119 and the crack 121 are generated depending on the shape of the emboss and the thickness of the work W.

An object of the present invention is to provide an embossing method and an embossing mold capable of performing good embossing without causing necking or cracking in the shoulder portion of the embossing.

[0008]

To achieve the above object, an embossing method according to the present invention according to claim 1 comprises:
A punch having a groove-shaped concave molding surface in which the groove width near both ends is enlarged in a divergent shape at a lower portion, and a convex molding surface corresponding to the vicinity of the center of the concave molding surface, and attached above the convex molding surface. An embossing method comprising: cooperating with a die having a protruding arc-shaped forming surface to perform embossing on a plate-like work in the next step.

(A) A step of forming an arc-shaped forming portion on a work in cooperation with a concave forming surface of a punch and an arc-shaped forming surface of a die.

(B) A step of deforming the arc-shaped molding portion by cooperation of the concave molding surface of the punch and the convex molding surface of the die to process the embossed molding portion.

According to a second aspect of the present invention, there is provided an embossing mold having a punch having a groove-shaped concave molding surface which is enlarged in a divergent shape and has a groove width near both ends at a lower portion, and a die which cooperates with the punch. A spherical chip having a convex molding surface provided at a position corresponding to the concave molding portion and having an arc-shaped molding surface protruding from the convex molding surface constantly urged upward by a first urging member in the convex molding surface. And an ejector urged by a second urging member above the die is provided.

Therefore, after the concave forming surface of the punch and the arc-shaped forming surface of the spherical tip of the die cooperate with each other to process the arc-shaped forming portion on the workpiece, the concave forming surface and the die are formed in this portion. By performing the embossing in cooperation with the convex forming surface, a good embossed product without necking or cracking at the shoulder of the embossed product can be obtained.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 1, an embossing mold 1 is constructed by combining a pair of punches 3 and a die 5, and is incorporated in a press. The punch 3 is hit by a striker from above in FIG. 1 and moves up and down. Punch 3
Has a groove-shaped concave molding surface 7 in which the width of the groove near both ends is enlarged in a divergent manner. The ejector 9 is provided above the die 5 by being urged by a spring 11.

In the center of the die 5, a concentric guide hole 1 is provided.
3, a hole 15 is formed extending in the up-down direction, and a backup plate 17 is provided integrally therewith under the die 5. A convex molding surface 19 is provided at a position of the die 5 corresponding to the concave molding surface 7, and is mounted in a hole 21 formed in the ejector 9. The upper surface of the convex molding surface 19 is higher than the upper surface of the ejector 9. It is sunk downward. A spherical tip 23 is provided in the convex molding surface 19.
That is, the spherical tip 23 is formed at the tip of the arc-shaped molding surface 2.
3a, a cylindrical portion 23b and a flange portion 23c. The cylindrical portion 23b is precisely guided by the guide hole 13, and is provided so as to be able to move in the direction in which the punch 3 is moved up and down, that is, in the up and down direction. A spring 25 is provided between the lower surface of the flange portion 23c and the upper surface of the backup plate 17, and constantly urges the spherical tip 23 upward. Therefore, normally, the upper surface of the flange portion 23c contacts the stepped portion 27 formed at the boundary between the guide hole 13 and the hole 15, and determines the initial position of the spherical tip 23.

FIG. 1 shows an initial state before the start of the molding operation. The punch 3 is separated upward, and the work W
Is set on the upper surface 9a of the ejector 9. The tip spherical portion 23a of the spherical tip 23 is located below the upper surface 9a of the ejector 9, and the upper surface of the convex molding surface 19 of the die 5 is located further below.

When the punch 3 is moved up and down by the striker and descends, the work W is sandwiched between the lower surface 3a and the upper surface 9a of the ejector 9.

When the punch 3 further descends, the work W descends while being sandwiched between the lower surface 3a of the punch and the upper surface 9a of the ejector 9 in the peripheral portion. The force for sandwiching the work W is determined by the urging forces of the plurality of springs 11. At the center of the workpiece W, the arc-shaped molding surface 23 of the spherical tip 23
a comes into contact with the workpiece W, but at this stage, the spring 2 is used to prevent the spherical tip 23 from falling.
5 is set to a sufficiently large value. Therefore, at this point, as shown in FIG. 2, the work W is deformed while having relatively uniform elongation and becomes a spherical shell. The height and radius of the arc-shaped forming surface 23a of the spherical tip 23 are selected to appropriate values according to the thickness, material, and final formed shape of the work W.

When the punch 3 is further lowered and the processing proceeds, the spherical tip 23 starts to lower. That is, the center of the work W is deformed, and the punch 3 and the arc-shaped forming surface 23a are deformed.
And the spherical tip 23 starts to descend only when it is no longer deformed. In this case, the amount of deformation at the time of forming the spherical shell can be selected to a desirable value.

When the spherical tip 23 descends, the work W comes into contact with the convex forming surface 19 of the die 5 and the emboss forming process starts in cooperation with the concave forming surface 7. In this situation, processing is performed without concentration of elongation at the shoulder of the emboss. The molding is completed in the state shown in FIG.

As described above, in the embodiment of the present invention, the arc-shaped molding surface 23a of the spherical tip 23 is formed.
And the concave molding surface 7 and the molding by the convex molding surface 19 and the concave molding surface 7 are completed in one step, so that the embossed shoulder does not become constricted or cracked, and
Mold cost, molding process, and molding time can be reduced.

The present invention is not limited to the above-described embodiments of the present invention, but can be embodied in other forms by making appropriate changes.

[0023]

As will be understood from the above description of the embodiments of the present invention, according to the first and second aspects of the present invention, the formed embossed shoulder does not become constricted or cracked. A good embossed product can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embossing mold according to the present invention.

FIG. 2 is a diagram illustrating the operation of the present invention.

FIG. 3 is an operation explanatory view of the present invention.

FIG. 4 is a cross-sectional view of a conventional embossing mold.

FIG. 5 is an explanatory diagram of a conventional operation.

FIG. 6 is an explanatory view of a conventional operation.

FIGS. 7A, 7B, and 7C are diagrams showing a state of an embossed product obtained by a conventional embossing mold.

[Explanation of symbols]

 Reference Signs List 1 embossing mold 3 punch 5 die 7 concave molding surface 9 ejector 11 spring 19 convex molding surface 23 spherical tip 23a arc-shaped molding surface 25 spring

Claims (2)

[Claims] 1. A punch having a groove-shaped concave forming surface at a lower portion in which a groove width near both ends is enlarged in a divergent shape, and a convex forming surface corresponding to the vicinity of the center of the concave forming surface. An embossing method comprising: cooperating with a die having an arc-shaped forming surface which is urged upward from a surface to project and embosses a plate-like work in the next step. (A) A step of processing an arc-shaped forming portion on a work in cooperation with a concave forming surface of a punch and an arc-shaped forming surface of a die. (B) a step of deforming the arc-shaped molding portion in cooperation with the concave molding surface of the punch and the convex molding surface of the die to process the embossed molding portion. 2. A punch having a groove-shaped concave molding surface enlarged in a divergent shape having a groove width near both ends is provided at a lower portion,
A convex molding surface is provided at a position corresponding to the concave molding portion of the die which cooperates with the punch, and the convex molding surface is constantly urged upward by the first urging member in the convex molding surface and protrudes from the convex molding surface. An embossing mold comprising: an annular tip having a shape forming surface; and an ejector urged by a second urging member above the die.