JPS639889B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pre-hem die for processing a workpiece to be pre-hemmed (pre-bending) whose flange width is not uniform, particularly corner portions having different flange widths.

Examples of conventional pre-hem dyes include those shown in FIGS. 3 to 5. As an example of such a workpiece, an automobile door is shown in FIG. 1, and a partially enlarged view of the same figure is shown in FIG. In the figure, 1 is a car door, 2 is an outer panel of door 1, 2a is a particularly small corner flange, and 2b
are slightly wider peripheral flanges on both sides of 2a.

3 is the inner panel of door 1, and the outer panel 2
By hemming the flanges 2a and 2b, the door 1 is integrated with the outer panel 2, but as a pre-process for this integration, the flanges 2a and 2b are bent inward to some extent, i.e. Perform prehemming. FIG. 3 shows a schematic sectional view of a press equipped with a pre-hem die for this purpose. 4 is an upper holder, and 5 is a sectional die fixed to the upper holder, which is used to pre-hem the wider flange 2b of the outer panel 2.

Reference numeral 6 denotes a pad provided on the upper holder via an elastic body 7, and is adapted to press the inner panel 3 stacked so as to face the outer panel 2 against a punch 9 fixed to the lower holder 8 during processing. .

Now, when the upper holder 4 descends, the pad 6 first
contacts the inner panel 3 as described above, and presses it against the outer panel 2 on the punch 9. Further, as the upper holder 4 descends, the slope 5a of the sectional die 5 contacts the flange 2b and bends it inward, pre-heming the flange 2b by a predetermined angle at the bottom dead center of the ram (not shown).

At this time, the sectional die 5 is attached to the flange 2.
When you start bending b and 2b inward (in the direction of arrows A and I in Figure 2), the flange 2a at the corner portion tends to bend outward (in the direction of arrow B in the figure), so to prevent this, flange 2a In the section, there is a sectional die 10 as shown in Figure 4.
is attached to the upper holder 4, and this sectional die 10 has a slope 10a and an extension part 10b that prevents the flange 2a from bending outward (in the direction of arrow B in FIG. 2). It descends while regulating the outside, and then begins to bend the flange 2a.

Further, FIG. 5 shows a case where the flange 2a is pre-hemmed by a cam instead of the sectional die 10 shown in FIG. 4. In the figure, 11 is a drive cam fixed to the upper holder 4;
Reference numeral 2 denotes a slide cam that is slidably provided on the lower holder 13 in the horizontal direction.As the upper holder 4 descends, the slide cam slope 12a is pushed by the slope 11a of the drive cam 11, and the slide cam 12
slides in the direction of arrow B to pre-hem the flange 2a by a predetermined angle. When the drive cam 11 is raised after machining, the slide cam 12 is returned to its original position by a return means (not shown).

However, in the case of pre-hem dies as shown in FIGS. 3 and 4, it is difficult to set the size of the clearance d between the flange 2a of the outer panel 2 and the extension part 10b of the sectional die 10, and even if d is too large, it is difficult to set the size of the clearance d. If it is too long, it will cause processing defects and it will be difficult to produce a stable product, and the processing of the flange 2a by the cam shown in FIG. However, the drive cam 11 and slide cam 12 are separated from each other when the mold is opened, and the upper holder 4 of the drive cam 11 is
Installation position and lower holder 1 of slide cam 12
Since the pre-hem processing time is determined by the relative positional relationship with the original position in 3, it is not easy to set the mounting position of each cam, and if the processing times of flanges 2a and 2b are not synchronized, product defects will occur. The dot was hot.

This invention was made by focusing on such conventional problems, and includes a drive cam fixed to an upper holder, a guide plate attached to both sides of the drive cam so as to face each other, and a vertical gap between the guide plates. The above-mentioned problems can be solved by using a pre-hem die characterized by comprising a slide cam that is slidably held in both the direction and the lateral direction, and an elastic body is interposed between the drive cam and the slide cam. It aims to solve the problem.

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

Note that parts corresponding to the conventional example are given the same reference numerals as those of the conventional example, and redundant explanation will be omitted.

6 to 8 are diagrams showing an embodiment of the present invention.

First, to explain the configuration, 21 is a drive cam fixed to the upper holder 4, 22 is a guide plate fixed to both sides of the drive cam with bolts, etc., 23
is a slide cam that is slidably held between opposing guide plates.

Reference numeral 24 denotes an elastic body such as urethane interposed between the drive cam 21 and the slide cam 23 at an angle;
24 is the drive cam 2 with the slide piece 26 in between.
1 and the slide cam 23 in the vertical direction.

The above parts, 21, 22, 22, 23, 2
Corner flange 2 by 4, 25, 26
A pre-hem die M for pre-hem processing a is configured.

Reference numeral 27 denotes a lower holder having an upper surface 27a on which the slide cam 23 slides laterally during processing, and when the mold is opened, the slide cam 23 and the lower holder 27 are separated from each other as shown in FIG.

Next, the effect will be explained.

As in the conventional example, the outer panel 2 and the inner panel 3 are placed on the punch 9, and when the upper holder 4 is lowered, the pad 6 first comes into contact with the inner panel 3, and then the pad 6 and the outer panel 2 are gradually pushed into the punch 9. Press firmly to stop the descent.

On the other hand, as the upper holder 4 descends, the pre-hem die M first brings the bottom surface 23a of the slide cam 23 into contact with the lower holder upper surface 27a, and at the same time, the slope 23c provided at the tip of the slide cam 23 approaches the tip of the flange 2a. At this time, the sectional die 5 shown in FIG.
This is just before it comes into contact with 2b. Then, when the upper holder 4 further descends, the slope 21 of the drive cam 21
b slides and presses the slope 23b of the slide cam 23 against the elasticity of the elastic bodies 24 and 25, so the slide cam 23 slides in the direction of arrow C;
As the ram of the press passes the bottom dead center, the flange 2a
Process the pre-hem to a predetermined angle. At this time, the slide cam 23 is raised by an amount h relative to the guide plate 22, as shown in FIG.

Next, as the processing is finished and the upper holder 4 rises, the force with which the elastic body 25 presses the slide cam 23 against the lower holder 27 gradually decreases.
The slide cam 23 is caused to slide in the direction opposite to the arrow C by the elasticity acting in the diagonal direction of the compressed elastic body 24, and when the upper holder 4 rises more than h, the guide plate 22 moves toward the slide cam. 23
(see Fig. 7), and as the ram approaches the top dead center, the pre-hem die M rises to the mold opening position.

On the other hand, the pad 6 is raised as in the conventional example, and the pre-hemmed outer panel 2 and inner panel 3 are carried out of the mold.

As explained above, according to the present invention, in a pre-hem die equipped with a drive cam and a slide cam, the structure includes a drive cam fixed to an upper holder, and guide plates mounted on both sides of the drive cam so as to face each other. and a slide cam held between the guide plates so as to be slidable in the vertical and lateral directions, and an elastic body is interposed between the drive cam and the slide cam. As a result, it is possible to easily synchronize the machining timing when pre-hemming the corners of workpieces with uneven flange widths, especially the corners where the flange width is small, and other flange parts, thereby greatly reducing the occurrence of product defects. This has the effect of lowering the amount of water.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the workpiece, Fig. 2 is an enlarged view of part A in Fig. 1, and Fig. 3 is a schematic cross-sectional view of the pre-hem die for processing parts other than the corners of the workpiece (Fig. 2).
Figure 4 is a partial enlarged cross-sectional view of a conventional example for machining the corner portion of a workpiece (a in Figure 2).
5 is a sectional view of a main part of a conventional example different from the conventional example shown in FIG. 7 and 8 are views taken along arrow D in FIG. 6. 4... Upper holder, 21... Drive cam, 22... Guide plate, 23... Slide cam, 24, 25... Elastic body.

Claims (1)

[Claims] 1 In a pre-hem die equipped with a drive cam and a slide cam, the drive cam is fixed to the upper holder, the guide plates are attached to face each other on both sides of the drive cam, and the guide plates can be slid vertically and laterally between the guide plates. 1. A pre-hem die comprising: a slide cam held by the drive cam; and an elastic body interposed between the drive cam and the slide cam.