JP2004202561A - Manufacturing method for joint press molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a joint press molding capable of easily and satisfactorily manufacturing a desired shape of a molding in simple processes even though a desired shape of the molding is difficult to mold. <P>SOLUTION: The manufacturing method for a joint press molding P, in which finally desired shapes are relatively difficult to mold such as drawing, is provided with a step joining a plurality of blanks 1 and 2, and a step pressing the plurality of the blanks. The manufacturing method comprises a step (a) preliminarily molding blanks 1 and 2, a step (b) preparing a preliminarily molded single blank B by joining the blanks 1 and 2 each other, and a step (c) pressing the blank B into a designated shape. A deformed amount of the blank B during a pressing process is set to be a little in a final process so that the blank B is molded by joining the preliminarily molded blanks 1 and 2 in advance. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a bonded press-formed product, and more particularly, to a method for manufacturing a bonded press-formed product formed by bonding a plurality of materials and press-forming the material into a predetermined shape.
[0002]
[Prior art]
As a conventional technique for manufacturing a joint press-formed product, it is known to form a collective blank formed by welding butted portions of respective steel sheets and to press-mold the collective blank (for example, see Patent Reference 1). Patent Literature 1 discloses an automobile body that does not require relatively deep drawing as a molding target.
[0003]
Also, as shown in FIGS. 1 to 3 (c), it is difficult to form the joined press-formed products P, P2, and P3, for example, because the finally desired shape is complicated or deep drawing is performed. There are cases. As a conventional technique for manufacturing the joined press-formed products P2 and P3 in such a case, as shown in FIG. 2, a plurality of pieces having a size and a shape divided according to the shape of the joined press-formed product P2 are used. Materials 21 and 22 are prepared (a). Next, it is known that the raw materials 21 and 22 are press-formed according to the shape of the bonded press-formed product P2 (b), and then the raw materials 21 and 22 are bonded to each other by welding or the like (c).
[0004]
Further, as another conventional technique, as shown in FIG. 3, blanks 31 and 32 made of a predetermined material are prepared by punching into a size and a shape divided according to the shape of the joined press-formed product P3. (A). Next, these materials 31 and 32 are first joined by welding or the like to form a single material (blank) B3 (b). Thereafter, it is known that the blank B3 is press-formed (c).
Each of the materials 21, 22 and 31, 32 shown in FIGS. 2 and 3 is made of the same plate thickness and the same material. However, depending on the part of the joined press-formed product, it may be necessary to change the plate thickness or the material. In such a case, each of the raw materials 21 and 22, and 31, 32 is made of a different plate thickness or material.
[0005]
[Patent Document 1]
Japanese Utility Model Publication No. Hei 3-24371
[Problems to be solved by the invention]
However, in Patent Document 1, although it can be effectively applied to press forming of a body of an automobile, as shown in FIGS. 1 to 3C, the shape is complicated and deep drawing is performed. For example, it could not be applied to the production of bonded press-formed products P, P2, and P3, which are difficult to form.
[0007]
In the conventional technique shown in FIG. 2, it is necessary to repeatedly change the shape of each of the materials 21 and 22 and adjust the mold so that the product does not crack or wrinkle during press molding. For this reason, there are problems that it takes time and cost, and the degree of freedom in the shape design of the joined press-formed product P2 is low. Further, depending on the shape of the joining press-formed product P2, it is necessary to further divide and configure the material 21 or 22 at a portion where molding is difficult. However, there is a problem that the number of forming press dies required for the process increases or the manufacturing cost increases due to complexity. In order to alleviate these problems, it is conceivable to use materials having good moldability as the materials 21 and 22. However, since such materials are expensive, manufacturing costs increase. There was a problem. Further, in the conventional technique shown in FIG. 2, since the materials 21 and 22 are joined in the final step (c), there is a problem that the molding accuracy of the joined press-formed product P2 may be reduced.
[0008]
Further, in the conventional technique shown in FIG. 3, the strength of the welding line W for joining the materials 31 and 32 to each other is reduced particularly due to a temperature change during welding, so that the welding line W It is necessary to prevent W from being positioned, and it is necessary to change the shape of each of the materials 31 and 32 and the shape of the joint press-formed product P3, and the degree of freedom in the shape design of the joint press-formed product P3 is low. There was such a problem. Further, in order to alleviate such a problem, there has been a problem that the number of steps for joining the materials 31 and 32 and the number of forming press dies required for each step are increased or complicated, and the manufacturing cost is increased. In order to alleviate these problems, it is conceivable to use materials having good moldability as the materials 31 and 32. Such materials are used in the conventional technology shown in FIG. Similarly, there is a problem that the manufacturing cost increases due to the high cost.
[0009]
The present invention has been made in view of the above-described problems, and easily and satisfactorily manufactures a molded article having a desired shape in a simple process even if the desired molded article has a difficult shape. It is an object of the present invention to provide a method for manufacturing a joined press-formed product that can be used.
[0010]
[Means for Solving the Problems]
The invention according to a method for manufacturing a bonded press-formed product according to claim 1 is a method for manufacturing a bonded press-formed product obtained by bonding a plurality of materials and press-forming into a predetermined shape to achieve the above object, Each material is preformed, the materials are joined to each other, and the joined materials are press-formed into a predetermined shape.
According to the first aspect of the present invention, first, a plurality of materials formed into a predetermined shape are preformed to a preform that is less than the final shape. Next, the preformed materials are joined by welding or the like to form a preformed single material. Thereafter, the preformed single material is formed into a predetermined shape by a press to produce a molded product. Since the raw materials are joined together in a preformed state to form a single unit, press molding requires only a slight deformation, so that a good molded product is manufactured without difficulty.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the method for manufacturing a bonded press-formed product of the present invention will be described in detail with reference to FIG. Note that the same reference numerals indicate the same or corresponding parts.
The present invention is a method of manufacturing a joined press-formed product P in which a plurality of materials 1 and 2 are joined together and press-molded, and finally the desired shape is a shape that is relatively difficult to form such as drawing. Then, each of the blanks 1 and 2 is preformed (a), and the blanks 1 and 2 are joined together to form a preformed single blank B (b), and the blank B is press-formed into a predetermined shape. (C).
[0012]
The shape of the joined press-formed product P ((c) in FIG. 1) manufactured in this embodiment is almost the same as the joined press-formed products P2 and P3 shown in (c) of FIGS. 2 and 3 respectively. Is set. In this embodiment, two plate-shaped materials 1 and 2 are prepared. The material 1 and the material 2 can have the same plate thickness, material, and the like, and can have at least one condition such as the plate thickness and the material different if necessary.
[0013]
In manufacturing the joint press-formed product P, first, materials 1 and 2 having a predetermined shape are respectively punched from a general high-strength steel plate having a predetermined thickness, and are preformed to a preform (FIG. 1 (a)). Here, the preforming means that when the blank B formed by joining the respective materials 1 and 2 is subsequently drawn by press forming, large elongation or wrinkles which cause cracks in the material are not generated. In addition, it means that the raw materials 1 and 2 are processed into a shape (preliminary shape) that approximates the shape of the finally desired bonded press-formed product P. In the preforming in this embodiment, a flat high-strength steel plate is punched into a predetermined shape to obtain the raw materials 1 and 2, and the bending is performed simultaneously with the punching of the raw material 1. The bending of the plate-shaped material 1 can be easily and easily performed. The present invention is not limited to this embodiment, and includes a step of punching blanks 1 and 2 of a predetermined shape from a flat high-strength steel sheet and a step of bending blanked blank 1. It can be done individually.
[0014]
Next, the blanks B are formed by joining the preformed materials 1 and 2 by welding or the like (FIG. 1B). When the blanks B are formed by joining the two materials 1 and 2 by welding, butt welding, fillet welding, and the like can be applied as necessary.
[0015]
Thereafter, the blank B is placed in a press mold and is finally formed into a desired shape (FIG. 1C). Further, in this embodiment, a process for forming the hole 3 in the portion (2) that was the material 2 is performed simultaneously with the drawing of the blank B. At this time, since the blank B is formed by joining the preformed materials 1 and 2 in advance, the deformation amount at the time of press forming the blank B by the press die in the final step is set to a small amount. . Therefore, since unreasonable stress which causes cracks and wrinkles is not applied to the blank B, even if the joining press-formed product P to be manufactured has a shape that requires relatively difficult forming such as deep drawing. With only a simple die adjustment, it is possible to easily and satisfactorily manufacture the joined press-formed product P having such a shape in a state of high rigidity. Further, the degree of freedom in the shape design of the desired joined press-formed product P Is improved. Further, since it is not necessary to use expensive materials having good moldability as the raw materials 1 and 2, the joint press-formed product P can be manufactured at low cost. Since the joined press-formed product P manufactured according to the present invention is press-formed in the final step, the dimensional accuracy is also improved.
[0016]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, even if the desired shape of the molded article requires difficult molding such as deep drawing, the molded article of the desired shape can be easily and favorably manufactured with high rigidity by a simple process. It is possible to provide a method for manufacturing a joint press-formed product that can be performed.
[Brief description of the drawings]
FIG. 1 is a perspective view for explaining a method for manufacturing a bonded press-formed product according to the present invention.
FIG. 2 is a perspective view for explaining a conventional method for manufacturing a bonded press-formed product.
FIG. 3 is a perspective view for explaining a method for manufacturing a conventional bonded press-formed product different from FIG. 2;
[Explanation of symbols]
1 Material 2 Material B Blank P Joined press-formed product

Claims (1)

A method for manufacturing a joined press-formed product obtained by joining a plurality of materials and press-molding to a predetermined shape,
Preforming each material,
Joining the materials together,
A method for manufacturing a bonded press-formed product, comprising press-forming the bonded material into a predetermined shape.

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