JP2002331316A - Press forming apparatus for two-ply product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press forming apparatus for a two-ply product capable of press-forming the two-ply product which overlaps flat components on the product main body, using a blank stock by bonding No.2 plate stock 3' to be flat components to No.1 plate stock 2' to be the product main body and the press forming apparatus is provided with a punch 10 opposed to No.2 plate stock 3' and a die 11 opposed to No.1 plate stock 2' and in the condition that the outer edge section of No.1 plate stock 2' is constrained, No.1 plate stock 2' is bulge-formed and when No.2 plate stock 3' being formed without any constraint, the press forming apparatus is capable of preventing cracks in No.1 plate stock 2' in the specific region of No.2 plate stock 3' which causes shrinkage in materials at the time of forming. SOLUTION: In the section of the punch 10 conforming to the specific region of No.2 plate stock 3', a recessed section 10a which works as an escape place for materials in the specific region against shrinkage of materials is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press forming apparatus for forming a two-ply product in which a metal plate-like part is superimposed on a metal product body.

[0002]

2. Description of the Related Art Conventionally, this type of two-ply product is manufactured by separately press-forming a product main body and a plate-shaped component, and then bonding the plate-shaped component to the product main body by welding or the like. However, this method requires separate press forming apparatuses for the product main body and the plate-shaped part, and has a problem that the production cost of the product is increased.

[0003] Therefore, it is desired to press-form a product using a single press-forming apparatus using a blank material obtained by joining a second plate material as a plate-like component to a first plate material as a product body. In this case, a press forming apparatus including a die facing the first plate material side of the blank material and a punch facing the second plate material side is used, and one of the die and the punch is pushed toward the other. Then, while the outer edge of the first plate is restrained, the first plate is stretched into the shape of the product main body, and the second plate is unconstrained to be formed into the shape of a plate-like component overlapping the product main body. Can be considered.

[0004]

As described above, when the first plate is stretched and formed while the second plate is not restrained, the first plate is stretched under the reaction force from the second plate. It is. As shown in FIG. 4, in a portion where the second plate material serving as the plate-shaped component 3 is formed while the material is shrunk, such as an end portion of the rib portion 2 a of the product, as shown in FIG. The wrinkles a caused by the shrinkage of the first body are pushed, and the first plate material serving as the product main body 2 is pushed by the wrinkles a, and an excessive tensile force acts on the first plate material to generate a crack b in the product main body 2. There is.

[0005] In view of the above, it is an object of the present invention to provide a press forming apparatus capable of forming a two-ply product satisfactorily without causing cracks.

[0006]

Means for Solving the Problems In order to solve the above problems,
The present invention provides a blank formed by joining a metal product main body with a metal plate-like component and superposing a metal plate-like component, and joining a first plate material serving as a product main body with a second plate material serving as a plate-like component. A press forming apparatus for forming a blank using a material, comprising: a die facing a first plate material side of a blank material; and a punch facing a second plate material side, with one of the die and the punch facing the other. The first plate is stretched into the shape of the product body while the outer edge of the first plate is restrained while the second plate is unconstrained and overlaps the product body. In molding to form a second material, the material shrinks during molding.
A concave portion is formed in a portion of the punch corresponding to a specific portion of the plate material as a place where the material at the specific portion escapes when the material shrinks.

[0007] According to the present invention, wrinkles due to shrinkage of the material are generated in a specific portion of the second plate material so as to enter the concave portion of the punch. For this reason, wrinkling in the direction of pushing the first plate material is suppressed, and a two-ply product can be molded favorably without causing cracks in the first plate material.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows a two-layer product comprising a metal product main body 2 and a double-strength plate-like component 3 superposed on the inner surface of a rib 2a of the product main body 2. FIG. 1 is shown. This product 1 is, as shown in FIG.
A blank material 1 'formed by joining a relatively thick second plate material 3' to be a plate-shaped component 3 to a relatively thin first plate material 2 'by an adhesive or spot welding at the center in the width direction. Press molded using

The press forming apparatus for the two-ply product 1 is shown in FIG.
As shown in FIG. 1, the apparatus includes a lower punch 10, an upper die 11 which can be moved up and down, and a blank holder 12 arranged around the punch 10 and urged upward via a pin 12a. When press-forming the two-layer product 1, first,
As shown in FIG. 2 (A), the blank material 1 is placed in the press forming apparatus such that the outer edge of the forming area of the first plate material 2 ′ is seated on the blank holder 12 with the second plate material 3 ′ down. ', And the die 11 is lowered toward the punch 10. According to this, the outer edge of the first plate member 2 ′ is formed by the die face portion 11 a of the die 11 and the blank holder 12.
And is restrained by being sandwiched between
Is pressed down together with the blank holder 12 by the die 11. Then, when the second plate 3 'comes into contact with the punch 10, the overhang forming of the first plate 2' is started as shown in FIG. 2B.

In the initial stage of the stretch forming, the deformation of the portion of the first plate 2 'overlapping with the second plate 3' is restricted, and as shown in FIG. 2B, the first plate 2 'is mainly formed. The portion not overlapping the second plate 3 'is deformed while elongating. Thereafter, as shown in FIG. 2 (C), the second plate 3 'is also deformed, and finally, as shown in FIG.
As shown in FIG. 1D, a blank 1 'is sandwiched between a punch 10 and a die 11, and both a first and a second plate 2', 3 '.
Have the required shapes matching the punch 10 and the die 11, respectively, ie, the shape of the product body 2 and the plate-like part 3 overlapping the product body 2.
It is molded in the shape of

Here, the outer edge of the second plate 3 'is not sandwiched between the blank holder 12 and the die 11, and the second plate 3'
Is formed without restraint and without elongation of the material. The specific portion 3'a of the second plate 3 'that matches the end of the rib portion 2a of the product body 2 causes the material to shrink in addition to bending during the molding. Therefore, in this state, as shown in FIG. 4, wrinkles a in the direction of pushing the first plate member 2 ′ approach the specific portion 3 ′ a, and a crack b is formed in the first plate member 2 ′, that is, the product body 2. Can occur.

Therefore, in the present embodiment, as shown in FIG. 3A, a portion of the punch 10 that matches the above-described specific portion 3'a of the second plate 3 ', which causes the material to shrink during molding, as shown in FIG.
A recess 10a is formed. According to this, the concave portion 10a
Is a place where the material at the specific portion 3'a escapes from the shrinkage of the material, and as shown in FIG. 3B, wrinkles a 'due to the shrinkage of the material are generated so as to enter the recesses 10a, and the first plate 2' is removed. Wrinkling in the pushing direction is suppressed, and cracking of the product main body 2 is prevented. In the present embodiment, the concave portion 10a is formed at a portion corresponding to two portions between the one end in the circumferential direction and the center and between the other end and the center in the circumferential direction of the specific portion 3'a. However, the present invention is not limited to this. For example, concave portions may be formed at portions corresponding to the three positions of both ends and the center of the specific portion 3'a in the circumferential direction.

In the above, the press forming apparatus in which the die 11 is arranged above the punch 10 has been described. However, the punch 10 and the die 11 are turned upside down, and a blank presser which is urged downward around the punch 10 is provided. After setting the blank 1 ′ with the second plate 3 ′ facing up on 11, the punch 10 is lowered to move the outer edge of the first plate 2 ′ between the blank holder and the die face. The present invention can be similarly applied to a press forming apparatus in which the second plate member 3 'is formed without restriction while the first plate member 2' is stretched and formed in this state.

[0014]

As is apparent from the above description, according to the present invention, wrinkling in the direction of pushing the first plate material at a specific portion of the second plate material is suppressed, and the two-ply product is not cracked. Good molding can be performed without occurrence.

[Brief description of the drawings]

FIG. 1A is a perspective view of an example of a two-layer product, and FIG.
Perspective view of an example of a blank material used for molding this product

2A is a cross-sectional view showing a setting state of a blank material in a press forming apparatus according to the present invention, FIG. 2B is a cross-sectional view of an initial stage of molding, FIG. 2C is a cross-sectional view of an intermediate stage of molding, and FIG. Cross section of the final stage

3A is a perspective view of a punch, and FIG. 3B is a perspective view of FIG.
Sectional view at the time of product molding cut along the IIIB-IIIB line

FIG. 4 is a perspective view of a two-ply product formed using a punch having no concave portion.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 double-stacked product 2 product main body 3 plate-like component 1 ′ blank material 2 ′ first plate material 3 ′ second plate material 3 ′ a specific part 10 punch 10 a recess 11 die 12 blank holder

Claims (1)

[Claims] 1. A two-ply product in which a metal plate-like component is superimposed on a metal product main body, and a second plate material as a plate-like component is joined to a first plate material as a product main body. A press molding apparatus for molding using a blank material, comprising: a die facing a first plate material side of the blank material; and a punch facing a second plate material side, wherein one of the die and the punch is the other. The first plate is stretched into the shape of the product body while the outer edge of the first plate is restrained while the second plate is unconstrained and overlaps the product body. In the shape forming, a concave portion is formed in a portion of the punch corresponding to a specific portion of the second plate member which causes the material to shrink during the molding, the concave portion serving as a place for the material at the specific portion to escape from the material shrinkage. Press forming equipment for two-ply products.