JPH03169436A - Pressing work method - Google Patents

Abstract

PURPOSE:To form the bulging part of un-uniform height at a low cost by drawing the sheet like blank material, forming the bulging part having the bottom part, the steeply inclining part and gently inclining part and then bending it and forming the standing up part higher than the steeply inclining part. CONSTITUTION:The drawing work is executed by holding the peripheral part of the sheet like blank material 30 with the blank holder of the pressing device. Thus, the intermediate product 32 constituted of the bulging part 34 and the blank holder part 36 is obtained. The above bulging part 34 has the bottom part 38 parallel to the blank holder 36, the steeply inclining part 40 which stands up from the boundary part 44, the gently inclining part 42 and its intermediate inclining surface part 48. Accordingly, with respect to the distance from the boundary part 44 of the above bottom part 38 to the boundary part 46 of the blank holding part 36, that of the gently inclining part 42 is larger than that of the steeply inclining part 40. Next, after the above blank holder part 36 is punched to the prescribed shape, the gently inclining part 42 is bent and the boundary part 44 with the bottom part 38 is bent and stood up until the same incline angle with the steeply inclining part 40, and the higher stank-up part 20 than steeply inclining part 40 is formed and the incline part 48 is extinguished. Further, the blank holding part 36 is bent back with approaching-bending work and the flange part 24 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a press working method, and in particular to a press working method for a product having an overhanging part having a bottom part and a rising part rising from the bottom part at uneven heights. This relates to processing methods.

Conventional technology A product with a protruding part having a bottom and a rising part rising from the bottom is produced by pressing a flat material. ) is commonly practiced. First, the periphery of the flat material is pressed by the lower mold of the press and the wrinkle pressing surface formed on the wrinkle presser, and the material is drawn to form an overhanging part. The outer periphery is punched out and the product is made into a product.

During the drawing process, a so-called shock line is likely to occur at the boundary between the rising portion and the pressing portion. This is said to occur because the thickness of the material is locally reduced due to rapid tension and bending by the upper and lower dies of the press, which deteriorates the appearance of the processed product.

Therefore, for example, as described in Japan Institute of Invention and Innovation Technical Report No. 84-10143, the punch of the press device is configured with a first part that is movable in the vertical direction and a second part that is movable in the horizontal direction. First, the first part is applied to the center part of the material to form a gently sloped part between the center part and the wrinkle suppressing part, and then the second part is applied to the middle part of the gently sloped part to form the material. It has been proposed to reduce the occurrence of shock lines by pressing the material to flow into the rising part from both the wrinkle pressing part side and the bottom part side.

However, even with these methods, it is not possible to completely avoid the occurrence of shock lines.

Furthermore, depending on the shape of the product, deterioration in appearance has been avoided by cutting out the part where the shigok line has appeared or by making it into a bent part.

Problem to be Solved by the Invention However, in a product having a protruding part with a rising part whose height from the bottom is uneven, the above method cannot avoid deterioration in appearance due to shock lines. was there. That is, when drawing, generally, as shown by the broken line in Fig. 4, the wrinkle suppressing part is determined based on the upper end of the low rising part, and after forming the overhanging part, the P part is Since a high rising part is formed by extending the shock line on the same plane as the rising surface, it was unavoidable that a shock line would appear in the Q part of the high rising part.

On the other hand, if drawing is performed based on a high rising part, the inconvenience of shock lines appearing on the rising part can be avoided, but the drawing process is deeper than when using a low rising part as a reference, which results in material costs. In addition, there arises a problem that the wrinkle suppressing portion needs to be increased, and the yield of the material decreases. Furthermore, the low rising part is formed by cutting off the tip of the high rising part or by bending it into a flange, etc., but in the latter case, a shock line appears in the middle part of the flange etc. There was also the problem that the appearance became poor.

In addition, in areas where the amount of rise is different, the problem of poor appearance due to shock lines can be solved by changing the height of the wrinkle pressing surface, but in reality, the wrinkle pressing surface is almost parallel to the bottom of the product. This is impossible because the material cannot be restrained well unless it is a flat surface or a curved surface with a large radius of curvature.

Therefore, the present invention has been developed to produce a product having a bottom part and an overhang part having a rising part rising from the bottom part at uneven heights at a low cost, and to avoid deterioration in appearance due to shock lines. This was done with the goal of finding a method.

Means for Solving the Problems And the gist of the present invention is as follows: (a) The periphery of a flat material is pressed and drawn with a wrinkle pressing surface that is approximately parallel to the bottom of the product, and the bottom part and the bottom part have different inclinations from each other. A first step of forming an intermediate product with an overhang having a steeply sloped part and a gently sloped part rising to the same height at an angle, and (1)) converting the boundary between the gently sloped part and the bottom into and a second step of bending in a direction that increases the slope, and forming a rising portion higher than the steeply sloped portion.

Function: In this press working method, an intermediate product is formed by drawing in the first step, and has an overhang having a bottom, a steeply sloped portion, and a gently sloped portion, and in the second step, the gently sloped portion of the overhang is formed. The part is bent to form a high rising part.

In other words, if a high rising part and a low rising part are made to rise to the same height from the bottom of the overhang at different inclination angles, the length of the part with a gentle slope to the top will be longer than the part with a steep slope. By bending the gently sloped part in the direction of the steeper slope, a taller rising part can be created.

Effects of the Invention Therefore, shock lines are prevented from appearing on both the surfaces of the high rising portion and the flange portion following the low rising portion, and the appearance of the product is improved. Furthermore, there is no need for a rework process to remove the shock line, resulting in lower manufacturing costs. Note that a shock line occurs at the boundary between the rising part and the wrinkle holding part, but
This shrink line can be prevented from appearing on the surface of the product by cutting or bending the boundary portion after processing.

Further, compared to the case where the wrinkle pressing surface is set based on the upper end of the high rising portion and deep drawing is performed, the material cost is lower, and a decrease in the yield of the material can be avoided.

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

The outer panel 10 constitutes the outer surface of the automobile door, as shown in FIG. 3, and is formed by stretch molding. Belt line section 12 which is a part of outer panel 10
The bottom part 14 is partially enlarged in FIG.
and a rising portion l6 that rises obliquely upward from the bottom portion 14. The rising portion 16 includes a high rising portion 20 and a low rising portion 2.
2, and the upper end of each continues into an inwardly bent flange 24 approximately parallel to the bottom l4.

The method for manufacturing the outer panel 10 will be explained, especially regarding the belt line portion l2. First, as shown in FIG. 1(a), a flat material 30 is prepared and placed on the wrinkle pressing surface of a lower mold of a press device (not shown). Then, the periphery of the material 30 is pressed down by the wrinkle presser of the upper mold of the press machine, and the central part is subjected to a bulging process, thereby forming the intermediate product 32 shown in FIGS. 1(b) and 1(C). The intermediate product 32 is the overhanging part 3
4 and a wrinkle suppressing part 36, the projecting part 34 has a bottom part 38 that is substantially parallel to the wrinkle suppressing part 36, and a steeply sloped part 40 and a gently sloped part 42 rising from the bottom part 38. The steeply sloped part 40 and the gently sloped part 42 rise continuously at the same height from a straight line that defines the edge of the bottom part 38, and are made at different angles with the bottom part 38. It follows. Therefore, as shown in FIG. 1C, the length of the gently sloped part 42, that is, the distance from the boundary 44 with the bottom part 38 to the boundary 46 with the wrinkle suppressing part 36, is longer than the length of the steeply sloped part 40. As well as becoming longer, the steeply sloped part 40! A triangular inclined surface 48 is formed between the first inclined portion 42 and the inclined portion 42 . The above is the first step.

Next, the wrinkle suppressing part 36 of the intermediate product 32 is punched into a predetermined shape, and at the same time, a molding attachment hole 50 shown in FIG. 2 is punched in the wrinkle suppressing part 36.

Thereafter, bending is performed as shown in FIG. 1(d). The boundary portion 44 between the gently sloped portion 42 and the bottom portion 38 is bent to the same angle of inclination as the steeply sloped portion 40, whereby the sloped surface 48 disappears and the gently sloped portion 42 becomes a higher rising portion 20.
, the steeply sloped portion becomes a low rising portion 22, and the rising portion 16 of the belt line portion l2 takes shape. This is the second step.

Finally, bending is performed to fold back the wrinkle holding portion 36 toward the bottom portion 38 as shown in FIG. 1(e), and the flange 24 is shaped to complete the series of processing.

Incidentally, this flange 24 has a molding attachment hole 50 formed in the wrinkle suppressing portion 36 in advance.

Conventionally, processing was carried out by pressing the upper part of the lower rising part 22 with a wrinkle pressing surface above the two-dot chain line shown in FIG. However, in this embodiment, the periphery of the boundary part 46 of each rising part 20, 22 where the shock line appears is bent inward by the bending process to form the flange 24. The shock line does not appear on either the high rising portion 20 or the flange 24, and the appearance of the outer panel 10 is improved.

Furthermore, in this embodiment, the high rising portion 20 is formed without being bent even once during the processing process, so that the modification that was conventionally performed to remove shock lines is unnecessary, and manufacturing costs are reduced.

Furthermore, if a wrinkle pressing surface is set at the upper end of the high rising part 20 and deep drawing is performed, after punching the molding attachment hole 50 in the rising part, the upper part of the rising part is bent and the molding attachment hole is formed. However, in this embodiment, this is not necessary, and the equipment cost is reduced. It's cheap and worth it.

Note that in this embodiment, the high rising portion 20 is bent and raised until it is located on the same plane as the low rising portion 22, but this is not essential;
The slope may be steeper than the low rising portion 22, and conversely, the slope may be gentler.

In addition, the present invention can be implemented with various modifications and improvements 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 explanation of the drawing]

FIGS. 1(a) to 1(e) are explanatory diagrams each showing a press working process of an outer panel according to an embodiment of the present invention. FIG. 2 is a perspective view showing the belt line portion of the outer panel manufactured by the above processing steps, and FIG. 3 is a front view showing the entire outer panel. FIG. 4 is an explanatory diagram showing a comparison between the above processing method and a conventional processing method for the belt line portion. 10: Outer panel 12: Belt line part 14:
Bottom part 18: Overhang part 20: High rising part

Claims (1)

[Claims] A method for pressing a product having an overhanging part having a bottom part and a rising part rising up from the bottom part at uneven heights, the method comprising: A first step of pressing and drawing with parallel wrinkle pressing surfaces to form an intermediate product having a bottom and an overhanging part having a steeply sloped part and a gently sloped part rising from the bottom to the same height at mutually different slope angles. and a second step of bending the boundary between the gently sloped part and the bottom part in a direction in which the slope of the gently sloped part becomes stronger to form a rising part higher than the steeply sloped part. Pressing method.