JP2006082098A - Method for forming metallic formed body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a metallic formed body having a recessed portion on a part of a sidewall, by which method the metallic formed body can be formed so as to have a uniform wall thickness (including an approximately uniform thickness) over the whole region. <P>SOLUTION: The metallic formed body F is formed into a rectangular cylinder shape with a first sidewall 1, a second sidewall 2, a third sidewall 3, and a fourth sidewall 4. The first sidewall 1 has a recessed portion 5. The method for forming the metallic formed body F comprises a first step for forming a cylindrical first intermediate body having the same circumferential length as the circumferential length of the cross section of the formed body F, a second step for forming a second intermediate body from the cylindrical first intermediate body, the second intermediate body having first and second flat walls corresponding to the third and fourth sidewalls 3, 4 and first and second curved walls for connecting both of the first and second flat walls respectively, and a third step for finishing the forming of the first, second, third, and forth sidewalls 1, 2, 3, 4 by inserting the second curved wall side of the second intermediate body into a cavity of a third forming die, and then by carrying out a die closing operation while pushing a part of the first curved wall into the second intermediate body by means of a recessed portion forming projecting portion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for forming a metal molded body.

Conventionally, the first and second side walls that face each other, and the third and fourth side walls that connect the opposite side edges and the other opposite side edges of the both side walls, respectively, are formed in a rectangular tube shape, and As a method for forming a metal molded body having a uniform thickness throughout, the tubular metal material is subjected to diameter expansion processing and has the same circumference (including almost the same) as the molded body, and has a substantially elliptical cross section. A method using a step of obtaining a cylindrical intermediate and a step of forming the intermediate into a rectangular tube is known (see Patent Document 1).
Japanese Patent Laid-Open No. 11-47842 (FIG. 2)

  However, in the conventional method, it is not possible to mold a molded body having a concave portion on one side wall so as to have a uniform thickness.

  An object of the present invention is to provide the molding method capable of molding a metal molded body having a recess on one side wall so as to have a uniform thickness.

  In order to achieve the above object, according to the present invention, the first and second side walls facing each other, and the third and fourth side walls respectively connecting the opposite side edges of the both side walls and the opposite side edges of the both side walls, respectively. In order to form a metal molded body having a square tube shape and the first side wall having a recess, the first metal mold is used to expand the diameter of the tubular metal material, thereby forming the concave cross-sectional shape. A first step of forming a cylindrical first intermediate body having the same peripheral length as in the above, and the cylindrical first intermediate body is disposed between both pressing members of a second molding die, and then the pressing member First and second flat walls facing each other and corresponding to the third and fourth side walls by pressing a cylindrical first intermediate body in the normal direction thereof and plastically deforming the two intermediate walls Between one opposite side edges and the other opposite side edges A second step of forming a second intermediate body having first and second curved walls to be joined and having the same circumference as the circumference of the first intermediate body; and The second curved wall is inserted into a female cavity of the molding die so that the second curved wall abuts on the second side wall molding surface, and the first and second flat walls face the third and fourth side wall molding surfaces, Next, a part of the first curved wall is immersed in the second intermediate body by a concave molding convex portion protruding from the male first side wall molding surface of the third molding die, and the first curved wall is made to be in the first mold. Provided is a method for forming a metal molded body using the third step of finishing the molding of the first, second, third and fourth side walls by performing a mold closing process which is pushed by a side wall molding surface. Is done.

  By adopting the above-mentioned means, it is possible to obtain a first intermediate body having a uniform thickness in the first step, and to obtain a second intermediate body from the first intermediate body and a molded body from the second intermediate body. In the case of obtaining, it is possible to perform molding while suppressing the elongation of the first and second intermediates as much as possible. Thereby, a metal molded body having a uniform wall thickness can be obtained throughout.

  According to the present invention, the above-mentioned metal molded body having a recess in a part of the side wall is made uniform (almost uniform) throughout its thickness by using the specific means as described above. And a molding method that can be molded.

  Embodiments of the present invention will be specifically described below based on the embodiments of the present invention illustrated in the accompanying drawings.

  In FIGS. 1 and 2, an Al alloy molded body F as a metal includes first and second side walls 1 and 2 facing each other, between one opposite side edges of both side walls 1 and 2, and the other opposite side edges. The third side wall 3 and the fourth side wall 4 are connected to each other to form a rectangular tube shape. The first side wall 1 has a recess 5 over its entire length. The thickness t of the molded body F is uniform (including substantially uniform) throughout.

  Molding of the molded body F is performed through the following steps.

  (1) First step: An Al alloy pipe 7 as a tubular metal material shown in FIG. 3 is prepared, and the intermediate part forming region 8 of the Al alloy pipe 7 is divided into two first parts as shown in FIG. 2 is installed in the cavity 10 of the mold 9 and then subjected to a diameter expansion process for applying fluid pressure in the Al alloy pipe 7 to include the same (substantially the same) circumference as the concave cross-sectional shape shown in FIG. ) A cylindrical first intermediate body 11 having a circumference is formed. This circumference refers to the circumference at a half position of the wall thickness. After that, as shown in FIGS. 5 and 6, the scrap portion composed of the end wall 12 and the material portion 13 existing on both sides of the first intermediate body 11 is cut out.

  (2) Second step: The cylindrical first intermediate body 11 is placed on the base 15 of the second mold 14 and arranged between the first and second pressing members 16 and 17 as shown in FIG. To do. Next, the cylindrical first intermediate body 11 is pressed in the axial direction by the pressing members 16 and 17 and plastically deformed, thereby facing each other as shown in FIG. 7, the solid line, and FIG. The first and second flat walls 18 and 19 corresponding to the fourth side walls 3 and 4 and the first and second flat walls 18 and 19 connecting the opposite side edges and the other opposite side edges of the flat walls 18 and 19, respectively. A second intermediate body 22 having two curved walls 20 and 21 and having the same circumference (including substantially the same) as the circumference of the first intermediate body 11 is formed.

  (3) Third step: As shown in FIG. 9, the second intermediate 22 is brought into contact with the cavity 25 of the female mold 24 in the third mold 23, and the second curved wall 21 is brought into contact with the second side wall molding surface 26. In addition, the first and second flat walls 18 and 19 are inserted so as to face the third and fourth side wall molding surfaces 27 and 28, respectively, and then, as shown in FIG. In the third mold 23, the concave intermediate molding protrusion 31 protruding from the first side wall molding surface 30 of the male mold 29 is immersed in the second intermediate body 22 and the first curved wall 20 is pushed by the first side wall molding surface 30. By performing the moving mold closing process, the molding of the first, second, third and fourth side walls 1, 2, 3 and 4 is completed as shown in FIG.

  In the third step, when fluid pressure is applied to the second intermediate body 22, the entire second intermediate body 22 can be brought into close contact with the female and male dies 24 and 29 to improve dimensional accuracy.

Specific examples are as follows. Al alloy pipe 7: Material 5000 series Al alloy; outer diameter 90 mm, wall thickness 3.0 mm, heating temperature about 500 ° C .; fluid pressure in the first step: 1.0 MPa, temperature of first mold 9 about 500 ° C., 140 mm outer diameter of the first intermediate body 11; fluid pressure in the second step: 0.5 MPa; temperature of the second mold 14 is about 500 ° C .; distance 73 mm between the first and second flat walls 18 and 19; third step Fluid pressure at 1.5 MPa, the temperature of the third mold 23 is about 500 ° C., the third and fourth side wall molding surfaces 27,. 28, distance 75 mm; average thickness of molded body F 2.5 mm.
As shown in FIG. 12, for example, when the portion corresponding to the molded body F is included in a part of the frame member 32 as shown in FIG. The present invention can also be implemented as cold working.

It is a perspective view of a molded object made of Al alloy. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a perspective view of an Al alloy pipe. It is explanatory drawing of a 1st process. It is a perspective view of the 1st intermediate body which has a scrap part. It is a perspective view of a 1st intermediate body. It is explanatory drawing of a 2nd process. It is a perspective view of a 2nd intermediate body. It is explanatory drawing before a 3rd process start. It is explanatory drawing of the intermediate | middle stage of a 3rd process. It is explanatory drawing at the time of completion | finish of a 3rd process. It is a perspective view of a frame member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ......... 1st side wall 2 ......... 2nd side wall 3 ......... 3rd side wall 4 ......... 4th side wall 5 ......... concave 6 ......... Rid 7 ......... Al alloy pipe (tubular metal material) )
9 ......... First mold 11 ... First intermediate 14 ... Second mold 16 ... First pressing member 17 ... Second pressing member 18 ... First flat wall 19 ... Second flat wall 20 …… First curved wall 21 …… Second curved wall 22 …… Second intermediate 23 …… Third molding die 24 …… Female die 25 …… Cavity 26 …… Second sidewall molding surface 27 …… Third Side wall molding surface 28... Fourth side wall molding surface 29... Male 30... First side wall molding surface 31... Convex molding convex F.... Al alloy molding (metal molding)
t ……… Thickness

Claims (2)

  The first and second side walls (1, 2) that face each other, and third and fourth side walls (3) that connect between the opposite side edges of the both side walls (1, 2) and between the opposite side edges, respectively. , 4) and the first side wall (1) is formed into a rectangular tube shape, and the first side wall (1) is formed into a tubular shape using a first molding die (9) when forming a metal molded body (F) having a recess (5). A first step of forming a cylindrical first intermediate body (11) having the same circumferential length as the circumferential length in the concave cross-sectional shape by subjecting the metal material (7) to a diameter expansion process; and the cylindrical first intermediate The body (11) is disposed between the pressing members (16, 17) of the second mold (14), and then the cylindrical first intermediate body (11) is processed by the pressing members (16, 17). By pressing in the line direction and plastically deforming, they face each other and correspond to the third and fourth side walls (3, 4). The first and second flat walls (18, 19) and the first and second curved walls (20, 20) connecting the opposite side edges and the opposite side edges of the flat walls (18, 19), respectively. 21) and a second step of forming a second intermediate (22) having the same circumference as that of the first intermediate (11), and the second intermediate (22), In the cavity (25) of the female mold (24) in the third mold (23), the second curved wall (21) comes into contact with the second side wall molding surface (26), and the first and second flat walls ( 18, 19) are inserted so as to face the third and fourth side wall molding surfaces (27, 28), respectively, and then a part of the first curved wall (20) is inserted into the male part in the third molding die (23). The recess forming projection (31) protruding from the first side wall forming surface (30) of the mold (29) 2 The first, second, and third are closed by performing a mold closing process in which the intermediate body (22) is immersed and the first curved wall (20) is pushed by the first side wall molding surface (30). And a third step of finishing the molding of the fourth side wall (1, 2, 3, 4). The method for forming a metal molded body according to claim 1, wherein fluid pressure is applied to the second intermediate body (22) in the third step.

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