JPS6049053B2 - Press mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a press die that prevents processing wrinkles from forming on a stepped surface when a workpiece having a stepped surface is formed by a double action press.

Examples of press molds used in conventional double action presses include those shown in FIGS. 1 to 5.

Figures 1 and 2 show a panel (trunk lid outer), which is an automobile body part, as an example of the workpiece. 1 is a panel with a step surface 1a, and 2 is a panel without a step surface. be.

4 and 5 show press molds for forming the panels 1 and 2, etc., and FIG. 4 shows a cross section of the press mold corresponding to the - The cross-sections of the press molds corresponding to the Y direction are shown respectively.

3 is a punch fixed to an inner slide (not shown) via a punch plate 4, 5 is a blank holder fixed to an outer slide (not shown) via a riser 6, and 7 is a sliding surface with the blank holder during operation. This is a wear plate attached to the punch 3, and together with the punch 3, blank holder 5, etc., constitutes an upper die 8.

3a is a stepped portion formed on the punch 3 corresponding to the stepped surface 1a of the panel 1, and 3b is a main forming portion corresponding to a portion other than the stepped surface 1a.

A die 9 corresponds to the punch 3, is fixed to the bolster 10, and has a groove 9a corresponding to the heat 5a of the blank holder 5.

The heat 5a and the groove 9a are arranged at required locations on the surface corresponding to the die face 11 so as to increase the resistance of the panel material to sink into the mold when the panel material is gripped and deformed by the heat 5a and the groove 9a. It is set in. Now, when the press die is opened and the upper die 8 is near the top dead center, when the panel material W is placed on the die face 11 and the upper die 8 is lowered, the outer slide (not shown) The blank holder 5 descends and comes into contact with the panel material W, and presses it against the die face 11 to stop its descent.

Next, the punch 3 descends together with an inner slide (not shown), and the main molding part 3b first comes into contact with the panel material W and pushes it down, and furthermore, when the press is pressed down, the stepped part 3a is also completely flattened as shown in Fig. 5. The panel is formed by contacting the panel material W.

However, in the case of such a conventional press mold, as shown in FIG. 3, during molding, the tip of the main molding part 3b first comes into contact with the panel material W from the ridgeline of Ei, and then As the punch 3 is pushed into the die 9, an uneven tensile force is applied to the panel material W between the tip A and the peripheral opening of the die face 11, and until the stepped portion 3a comes into contact with the panel material W. Wrinkles S appear. Next, this wrinkle S
As a result of being crushed by the stepped portion 3a, after the breath is finished,
There was a problem in that shading distortion 1s occurred on the panel step surface 1a. Note that panel 2 does not have a stepped surface, so this problem does not occur.

This invention was made by focusing on such conventional problems, and in a double action press, the punch is divided into a main punch and an auxiliary punch forming a stepped part of the punch, and the auxiliary punch and main punch are separated. It is an object of the present invention to solve the above-mentioned problems by providing a press mold characterized by interposing an elastic body that urges an auxiliary punch toward the die side.

The present invention will be explained below based on the drawings.

6 to 11 are diagrams showing an embodiment of the present invention.
Note that the same reference numerals are given to parts corresponding to the conventional example, and redundant explanation will be omitted. To explain the structure, 13 is a punch fixed to the punch plate 4, 13a is a stepped portion of the punch, and 13b is a main punch forming the main forming portion of the punch.

Reference numeral 14 denotes an auxiliary punch for shaping the stepped surface 1a of the workpiece, and is held by being screwed onto a guide retainer 16 that is slidably fitted into a bush 15 fitted to the stepped portion 13a.

Reference numeral 17 denotes an elastic body interposed between the auxiliary punch 14 and the stepped portion 13a.

Further, the punch 13 is provided with wear plates (not shown) at required locations, and is adapted to come into sliding contact with the blank holder 5 during operation. The above-mentioned parts and the blank holder 5 constitute an upper die 18. Next, the effect will be explained.

Now, when opening the mold of the press, when the panel material W is placed on the die face 11 and the press is driven, the blank holder 5 descends together with an outer slide (not shown) and presses the panel material W against the die face 11. , stop the descent.

Next, the punch≦13 descends together with an inner slide (not shown), and the main punch 13b and the auxiliary punch 1 forming the main forming part are
4 come into contact with the panel W almost simultaneously (see FIGS. 6, 7, and 9).

When the punch 13 further descends, the auxiliary punch 14 and the main punch 13b squeeze the panel W while remaining substantially on the same plane, and the auxiliary punch 14 presses the panel W against the stepped portion 9a of the die 9 (see FIG. 10). ). The molding process up to this point is the same as the molding of the panel 2 without steps, and there are no wrinkles S as shown in FIG. 3.

Next, when the punch 13 further descends, the stepped portion 13a of the punch presses the stepped surface 1a of the panel W against the stepped portion 9a of the die via the auxiliary punch 14 while compressing the elastic body 17, and The punch 13b further narrows the panel W, and as shown in FIG. 11, the forming of the panel 1 having the step surface 1a is completed when the press is pressed.

When molding is completed and the inner slide 7 (not shown) rises together with the punch 13, the compression of the elastic body 17 is released, and the auxiliary punch 14 rises while being suspended by the guide retainer 16 and is removed from the panel W. Leave. On the other hand, the outer slide (not shown) also rises together with the blank holder 5, and the breath mold returns to the mold open state l. By repeating the above operations, a panel having a stepped surface is produced by molding.

Let's take a closer look at the molding process.

In the conventional press mold, the portion of the workpiece 1 corresponding to the stepped surface 1a was in a free state until the mold was pressed through, that is, there was a gap between the upper mold and the lower mold.

Therefore, wrinkles S could be generated freely. On the other hand, in the press type of the present invention, the part corresponding to the step surface 1a of the workpiece 1 is always pressed by the auxiliary punch 14.
It can suppress the appearance of wrinkles. As explained above, according to the present invention, the structure of the double action press is such that the punch is divided into the main punch and the auxiliary punch forming the stepped part of the punch, and the auxiliary punch and the main punch are separated. Because the press mold is characterized by inserting an elastic body that urges the auxiliary punch toward the die side,
It is possible to form a panel having a stepped surface without causing scratch distortion.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a panel with a step surface, Fig. 2 is a perspective view of a panel without a step surface. X
- A cross-sectional view of a press mold including a cross section in the X direction, FIG. 5 is a cross-sectional view of a conventional press mold including a cross section in the Y-Y direction of a panel having a cross-sectional surface, and FIG. 6 is a cross-sectional view of a press mold according to the present invention. A sectional view of the embodiment, FIG. 7 is an enlarged view of section A in FIG. 6, and FIG. 8 is an enlarged view of section A in FIG.
, ■1■ sectional view in Figure 7, Figures 9, 10, and 11 are as follows:
513 is a diagram showing the working process of each example.
...Punch, 13a...Step, 13b...
・Main punch, 14... Auxiliary punch, 17...
・Elastic body.

Claims (1)

[Claims] 1. In a double action press, the punch is divided into a main punch and an auxiliary punch that forms a stepped part of the punch, and an elastic body that urges the auxiliary punch toward the die is inserted between the auxiliary punch and the main punch. A press mold featuring: