JP2762634B2 - Press working method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a press working method,
The present invention relates to a method of processing a product having an overhang portion having a bottom portion and a rising portion rising from the bottom at an uneven height.

2. Description of the Related Art By pressing a flat material, a product having an overhang portion having a bottom and a rising portion rising from the bottom is drawn (in a broad sense, including overhang forming). It is generally done. First, the periphery of the flat plate-shaped material is pressed by the lower die of the press device and the wrinkle-pressing surface formed on the wrinkle-press to form an overhang portion by drawing the material, and then, the outer periphery of the wrinkle-press portion is formed. The product is made by punching and the like.

During the drawing, a so-called shock line is likely to occur at the boundary between the rising portion and the wrinkle holding portion. This is believed to occur because the plate thickness of the material is locally reduced due to rapid pulling and bending by the upper and lower dies of the pressing device, and the appearance of the processed product is reduced.

Therefore, for example, as described in Hatsumei Kyokai Disclosure No. 84-10143, the punch of the press device is constituted by a first portion movable in a vertical direction and a second portion movable in a horizontal direction. The first part is applied to the center of the material to form a gentle slope between the center and the wrinkle holder, and then the material is pressed by applying the second part to the middle of the gentle slope. It has been proposed to reduce the occurrence of a shock line by flowing a material into a rising portion from both sides of a wrinkle holding portion side and a bottom portion side. However, even with these methods, generation of a shock line cannot be completely avoided.

Further, depending on the shape of the product, it has been practiced to cut off the portion where the shock line has occurred or to form a bent portion to prevent the appearance from being deteriorated.

SUMMARY OF THE INVENTION However, in the case of a product having an overhang having a rising portion whose height from the bottom is not uniform, the above-described method cannot avoid deterioration in appearance due to a shock line. was there. That is, generally, when drawing is performed, as shown by a broken line in FIG.
After determining the wrinkle holding portion based on the upper end of the low rising portion and forming the overhang portion, the P portion is extended on the same plane as the rising surface to form a high rising portion, so that the high rising portion is formed. It was inevitable that the shock line would appear in the Q section.

On the other hand, if drawing is performed on the basis of a high rising portion, the inconvenience that a shock line appears at the rising portion can be avoided. Is higher,
In addition, it is necessary to increase the wrinkle holding portion, which causes a problem that the yield of the material is reduced. Furthermore, the low rising portion is formed by cutting off the tip of the high rising portion or forming it into a flange portion by bending, but in the latter case, a shock line appears in the middle portion of the flange portion or the like. There was also a problem that the appearance became worse.

In addition, in a portion where the rising amount is different, if the height of the wrinkle holding surface is changed, the problem of deterioration in appearance due to the shock line can be solved. Unless the surface is a flat surface or a curved surface having a large radius of curvature, the material cannot be satisfactorily restrained.

Accordingly, the present invention provides a press working that can manufacture a product having a bottom portion and an overhang portion having a rising portion that rises at an uneven height from the bottom portion at a low cost, and that can avoid deterioration in appearance due to a shock line. The task was to obtain a method.

Means for Solving the Problems The gist of the present invention is that (a) the periphery of a flat plate-shaped material is pressed with a wrinkle-holding surface substantially parallel to the bottom of the product and drawn, and different inclinations are formed from the bottom and the bottom. A first step of forming an intermediate product having an overhang having a steep slope and a gentle slope rising to the same height at an angle; and (b) slope of the gentle slope with a boundary between the gentle slope and the bottom. And a second step of forming a rising portion higher than the steeply inclined portion.

In this press working method, an intermediate product having an overhang having a bottom portion, a steep slope and a gentle slope is formed by drawing in the first step, and the gentle slope of the overhang is formed in the second step. The portion is bent to form a high rising portion.

That is, if the high rising portion and the low rising portion are raised from the bottom of the overhang portion to the same height at different inclination angles, the length of the gentle slope portion is longer than that of the steep portion to the upper end. Therefore, a high rising portion is formed by bending and raising a portion having a gentle inclination in a direction in which the inclination becomes strong.

Advantageous Effects of the Invention Therefore, it is possible to prevent a shock line from appearing on both surfaces of the high rising portion and the flange portion following the low rising portion, thereby improving the appearance of the product. Further, a rework process for removing the shock line is not required, and the manufacturing cost can be reduced. In addition, a shock line is generated at the boundary between the rising portion and the wrinkle holding portion, and this shock line can be prevented from appearing on the surface of the product by cutting or bending the boundary portion after processing. it can.

Also, the wrinkle-pressing surface is set with reference to the upper end of the high rising portion, and the material cost can be reduced as compared with the case where deep drawing is performed, and the effect of avoiding a decrease in material yield can be obtained.

Hereinafter, an embodiment in which the present invention is applied to the manufacture of an outer panel of an automobile door will be described in detail with reference to the drawings.

As shown in FIG. 3, the outer panel 10 constitutes the outer surface of the automobile door, and is formed by overhang molding. Belt line section 12 which is a part of outer panel 10
As shown in a partially enlarged view in FIG. 2, a bottom portion 14 and a rising portion 16 which rises obliquely upward from the bottom portion 14 are shown.
And an overhang portion 18 having the following. The rising part 16
It consists of a high rise 20 and a low rise 22, each upper end continuing to a flange 24 bent inward substantially parallel to the bottom 14.

A method for manufacturing the outer panel 10 will be described, particularly the belt line section 12. First, as shown in FIG. 1 (a), a plate-shaped raw material 30 is prepared and placed on a wrinkle holding surface of a lower die of a pressing device (not shown). Then, the periphery of the raw material 30 is pressed by a wrinkle press of the upper die of the press device, and a central portion is subjected to an overhanging process to form an intermediate product 32 shown in FIGS. 1 (b) and 1 (c). The intermediate product 32 includes an overhang portion 34 and a wrinkle holding portion 36, and the overhang portion 34 has a bottom 38 substantially parallel to the wrinkle holding portion 36 and a steeply inclined portion 40 rising from the bottom 38.
And a gentle slope portion 42. The steeply sloping portion 40 and the gentlely sloping portion 42 continuously rise at the same height from a straight line that defines the edge of the bottom portion 38, and the angles with the bottom portion 38 are different. Followed by
Therefore, as shown in FIG. 1 (c), the length of the gentle inclined portion 42, that is, the boundary portion 44 with the bottom portion 38, the wrinkle pressing portion 36
Is longer than the length of the steeply inclined portion 40, and a triangular inclined surface 48 is formed between the steeply inclined portion 40 and the gentlely inclined portion 42. The above is the first step.

Next, the wrinkle holding portion 36 of the intermediate product 32 is punched into a predetermined shape.
Next, a molding mounting hole 50 shown in FIG. 2 is punched out. Thereafter, a bending process is performed as shown in FIG. The boundary 44 between the gentle slope 42 and the bottom 38 is bent and raised to the same inclination angle as the sharp slope 40, whereby the slope 48 disappears, and the gentle slope 42 has a high rising section 20 and a sharp slope. A low rising portion 22 is formed, and a rising portion 16 of the belt line portion 12 is formed. This is the second step.

Finally, as shown in FIG. 1 (e), a bending process is performed to turn the wrinkle holding portion 36 back to the bottom portion 38 side, and the flange 24
Is formed, a series of processing ends. The flange 24 has a molding mounting hole 50 formed in the wrinkle holding portion 36 in advance.

In the prior art, since the upper part of the two-dot chain line shown in FIG. 2, that is, the upper part of the lower rising portion 22 is pressed by the wrinkle pressing surface to perform the processing, after the processing, the higher rising part 20 is formed along the two-dot chain line. There was a disadvantage that a shock line appeared, but in this embodiment,
Boundary part 4 of each rising part 20, 22 where the shock line appears
(6) Since the peripheral portion is bent inward by the bending process to form the flange 24, the shock line is high
The appearance of the outer panel 10 is improved because it does not appear on either of the surfaces 20 and the flange 24.

Further, in the present embodiment, since the high rising portion 20 is formed without being bent once in the processing step, it is not necessary to rework conventionally to remove the shock line, and the manufacturing cost is reduced.

In addition, when setting a wrinkle holding surface at the upper end of the high rising portion 20 and performing deep drawing, after punching out the molding mounting hole 50 at the rising portion, bending the upper portion of the rising portion to form the molding mounting hole. It is necessary to have a flange 24 with a hole, and a punching device including a shift cam is required for punching of the molding mounting hole 50, whereas in the present embodiment, it is unnecessary, and the device cost is reduced. It's cheap.

In the present embodiment, the high rising portion 20 is bent and raised until the high rising portion 20 is positioned on the same plane as the low rising portion 22.However, this is not indispensable, and the inclination is stronger than the low rising portion 22. On the contrary, a gentle inclination may be used.

In addition, the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art, such as applying the present invention to the manufacture of products other than outer panels.

[Brief description of the drawings]

1 (a) to 1 (e) are explanatory views showing press working steps of an outer panel according to one embodiment of the present invention.
FIG. 2 is a perspective view showing a belt line portion of the outer panel manufactured by the above-described processing step, and FIG. 3 is a front view showing the entire outer panel. FIG. 4 is an explanatory view showing a comparison between the above-mentioned processing method and the conventional processing method of the belt line portion. 10: Outer panel, 12: Belt line part 14: Bottom part, 18: Overhang part 20: High rise part 22: Low rise part, 24: Flange 30: Material, 32: Intermediate product 34: Overhang part, 36: Wrinkle holder Part 38: bottom, 40: steep slope 42: gentle slope, 44, 46: border

Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B21D 22/20 B21D 22/26 B21D 5/01

Claims (1)

(57) [Claims] 1. A method for press-working a product provided with an overhang having a bottom and a rising portion rising from the bottom at an uneven height, wherein a flat plate-shaped material is substantially parallel to the bottom. A first step of forming an intermediate product having an overhang portion having a steep slope portion and a gentle slope portion rising from the bottom and the bottom to the same height at different inclination angles from the bottom by pressing and drawing with a wrinkle holding surface; A second step of bending a boundary between the gentle slope and the bottom in a direction to increase the slope of the gentle slope to form a rising part higher than the steep slope. Processing method.