JPS5886939A - Work drawing method - Google Patents

Abstract

PURPOSE:To obtain plural work products having no crack, with good yield, by combining panels, simultaneously drawing them, forming a bead shape part in a crack generated part of an adjacent edge of a work, and advancing the generated crack along the bead shape. CONSTITUTION:Circular shape parts of steel plate panels 2' which have been cut to a prescribed shape are combined so as to be opposed and made to press- contact to each other, and are drawn between the upper and lower molds. At first, on a work adjacent edge A whose curved surface variation factor is high, a semi-circular bead shape part D is formed, and this part is made thin. When the drawing advances, a crack B is generated from one end of the thinned bead shape part D. This crack B advances only along the bead shape part, and exerts no influence on a body 1'. After the drawing has ended, an unnecessary adjacent edge is cut-worked by a one point chain line C. According to this method, a work product having no crack at all is obtained. This method is applicable to work drawing of a wheel house outer, etc. of an automobile, etc.

Description

[Detailed Description of the Invention] The disclosed technology is capable of processing and forming even if cracks occur during the drawing process of a workpiece such as a wheel house outer used for the body of a vehicle, etc., without the crack progressing to the workpiece body. Belongs to the technical field.

Therefore, in order to process and form a wheel house outer, etc. that forms a part of the body of a vehicle such as an automobile, the present invention involves drawing a workpiece to a material panel, and then forming the wheel house outer, etc. into a predetermined shape. This invention relates to a method for drawing a workpiece in which unnecessary adjacent edges of the workpiece are cut out and formed into a shape, and in particular, at least one pair of the material panels is shaped so that the workpiece can be closely opposed to each other to improve fractional distillation. Then, the combined material panels are drawn at the same time, and bead shapes are formed in the areas where cracks are likely to occur at the adjacent edges of the workpiece, and after the drawing process, the bead shapes are formed. This invention relates to a workpiece drawing method in which a plurality of workpieces can be obtained simultaneously by cutting off adjacent edges of the workpieces along which cracks have progressed during drawing.

As is well known, many automotive podiums are constructed by assembling press-formed or drawn steel panels.

Therefore, for example, the wheel house outer, wheel house inner, etc. located above the wheel of an automobile must be drawn to have a curved surface change from the contour shape of the wheel. There was a drawback that cracks occurred from the adjacent edges of the workpiece during drawing forming, and the cracking spread to the workpiece body when drawing was completed.

To deal with this, for example, as shown in Figures 1 to 3d,
When drawing the wheel house outer 1 as a workpiece, a rectangular steel plate panel 2 is used which has a wide area that will become the adjacent edge A of the wheel 7% width outer with respect to the wheel arch side portion of the wheel house outer 1. Drawing forming is performed between the upper die 3 and lower die 4 of the press drawing die, and as shown in Figures 6a to 3d, the wheel arch side portion of the wheel house outer 1 having a high rate of curved surface change during the drawing process. End cracks B tend to occur on the adjacent edge A of the wheel house outer, and by the end of the drawing process, the end crack B has progressed to the main body of the wheel house outer 1, and the adjacent edge A of the wheel house outer has a single dot chain @C in FIG. 3C. Even if the edge A is cut and formed, the wheel house outer 1 main body is cracked B.
There was a drawback that this problem also occurred.
'Therefore, in extreme cases, the product will be defective, and
There is a drawback that corrective processing requires a large number of man-hours and is cumbersome.

Furthermore, since the steel plate panel 2 having a wide area adjacent to the wheel house outer edge A is used, there is a disadvantage that the fractionation of the wheel house outer 1 with respect to the steel plate panel 2 is poor.

The purpose of this invention is to solve the problem of cracking caused by drawing process of a wheel house outer, etc., which has a high rate of curved surface change, which is used in the body of a vehicle such as an automobile based on the above-mentioned conventional technology.
Provided is a workpiece drawing method that allows cracks during drawing of the workpiece to progress to the bead shape by forming a bead shape on the adjacent edge of the workpiece at a portion with a high rate of curved surface change, thereby obtaining an excellent workpiece product free of cracks. This is what I am trying to do.

The structure of the present invention in accordance with the above-mentioned object is such that when drawing and forming a wheel house outer etc. that forms a part of a vehicle body such as an automobile, the adjacent edge of the workpiece is used to improve the fractionation of the workpiece to the material panel. At least one pair of panels having a minimum number of parts are combined in a shape that allows workpieces to face each other closely, and the combined panels are simultaneously subjected to a drawing process, and cracks are formed at the crack occurrence area on the adjacent edge of the workpiece in a workpiece area with a high rate of curved surface change. By molding bead-shaped parts that advance the workpiece, cracks during drawing of the workpiece can be removed from the adjacent edges of the workpiece.
The gist of this method is to allow the crack to progress to the shaped part, and then cut the adjacent edges of the vaginal work to prevent the crack from progressing and spreading to the work body.

Next, embodiments of the present invention in accordance with the above-mentioned objects will be described below with reference to FIG. 4 and the subsequent drawings. Furthermore, 1st~
The same parts as those in the 3D figure will be explained using the same reference numeral 0.

One embodiment shown below in Figure 4 is a work drawing process of a wheel house outer that is installed in the body above the wheel of an automobile.As shown in Figures 4 to 6d, the wheel house outer 1 as a work is drawn. When drawing and forming the wheel house outer 1', one length is formed into an arc shape so that the adjacent edge A of the wheel house outer 1' to the wheel arch side portion where the curved surface change rate is high has an area of the minimum range necessary for drawing. The steel plate panel 2' formed on the side is cut in advance.

Next, a pair of steel plate panels 2' and 2' are arranged on the 1F so that the arc-shaped portions of the steel plate panels 2' are brought into contact with each other alternately.
and the pair of combined steel plate panels 2', 2' are assembled into a fifth
As shown in the figure, it is a pre-pack type type having an arc-shaped recess 3' and a convex part 4' each provided at a predetermined position 1d at a predetermined location where cracks are likely to occur on the adjacent edge A of the outer wheel house. Draw forming is performed between an upper mold 3 and a lower mold 4.

When drawing and forming is carried out in this way, the 6th a.
As shown in the figure, a semi-circular bead shaped portion begins to be formed in the wheel house outer adjoining #A to the wheel arch side portion of the wheel house outer 1' where the rate of curved surface change is high. As it becomes thinner and the drawing process progresses further, as shown in FIG. 6, a crack B occurs at one end of the thinned bead-shaped portion of the adjacent edge A of the wheel house outer, and as shown in FIGS. At the time when drawing forming shown in is completed, the crack B propagates only along the bead-shaped portion of the thin-walled weak point of the adjacent edge A of the wheel house outer 1', and does not spread to the main body of the wheel house outer 1'. .

After the above-mentioned drawing process is completed, if the adjacent edge A of the wheel house outer of the unnecessary wheel arch side portion and other unnecessary adjacent edges are cut off in the post-processing process along the dashed end line C shown in FIG. 6C, cracks can be avoided. Completely absent wheel house outer 1
' will be able to obtain high quality products.

It goes without saying that the embodiments of the present invention are not limited to the above-described embodiments; for example, the bead-shaped portion may be formed into a rectangular shape, and the target workpiece may also be a wheel house outer. It goes without saying that it can be applied not only to wheel house inners, wheel house fronts, etc., but also to anything that has a curved surface change.

As described above, according to the present invention, a work such as a wheel house outer that forms a part of a vehicle body such as an automobile can be squeezed.
When forming and processing, the workpiece is drawn on the material panel, and a bead shape is formed on the adjacent edge of the workpiece where cracks are likely to occur in the adjacent part of the core workpiece, and the workpiece has a kneaded bead shape after the drawing process. By cutting and forming the adjacent edge, the end cracks on the adjacent edge of the workpiece that occur during drawing will only progress along the bead shape, so the cracking will not spread to the workpiece body, and therefore, the unnecessary adjacent edge of the workpiece will be removed. After the edge cutting force d process, a good product with no cracks can be obtained, and the man-hours for correcting cracks are no longer required, which greatly reduces the man-hours for modification in post-processing. Excellent effects are achieved.

Furthermore, by combining at least one pair of the panels into a shape that allows workpieces to face each other closely, and then simultaneously drawing the combined panels, it is possible to form a plurality of workpieces at the same time, and to divide the workpieces into the panels. This has the advantage of improving retention.

[Brief explanation of drawings]

Figures 1 to 3d show conventional workpiece drawing, where Figure 1 is an explanatory diagram of the shape of a steel plate panel, Figure 2 is a cross-sectional diagram of a press drawing die, and Figures 3a to 3d are drawings of a workpiece. Process explanatory drawings, Fig. 4 and the following are explanatory drawings of one embodiment of the present invention, Fig. 4 is an overall explanatory drawing of a combination panel, Fig. 5 is a cross-sectional explanatory drawing of a press drawing die, and Figs. 6a to 6d are explanatory drawings. It is an explanatory diagram of a workpiece drawing process. 2.2'...Panel, 1.1'...Workpiece,
A...Adjacent edge of workpiece, B...Crack, D...Bead shape Fig. 1 Fig. 30 Fig. 3b Fig. 3C Fig. 3d Fig. 4 Fig. 5 Fig. 60 Fig. 6b Fig. 6C

Claims (1)

[Claims] Spring) Lil In a drawing method in which a workpiece is drawn and then the adjacent edges of the workpiece are cut and formed into a predetermined shape, at least one pair of the panels is combined into a shape that allows the workpieces to closely face each other, and then the combined panel A plurality of workpieces are obtained by simultaneously drawing a plurality of workpieces, forming a bead shape in the crack occurrence portion of the adjacent edge of the workpiece, and cutting and forming the edge having the bead shape after the drawing process. Workpiece drawing method.