JPH0225287A - Cold press welding method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a cold pressure welding method for joining a plurality of metal members by applying pressure.

(Prior art) For example, in a transformer that uses a sheet-like conductive metal plate (for example, an aluminum plate) as a coil,
Joining the aluminum plates that make up the coil,
A cold pressure welding method is used to join the aluminum plate and the copper plate at the coil outlet. Cold pressure welding is a method of joining multiple metal parts by mechanically pressurizing them with a mold without using a heat source.
It has the feature of being able to join metal members of different types.

3 and 4 show an example of a conventional cold pressure welding method. When performing cold pressure welding, first, the oxidized wave film on the surfaces of, for example, three metal members 1, 2.3 to be joined is removed with a wire brush-like object, and each of these metal members 1, 2.
Overlap 3. In this case, the upper and lower metal members 1.3
is an aluminum plate, and the intermediate metal member 2 is a copper plate.

Then, the mating portion 4 is placed between an upper mold 5 and a lower mold 6 which have uneven shapes facing each other, and
Bonding is achieved by mechanically pressurizing the overlapped parts 4 by means of the lower chamber 5.6. In this case, upper and lower chambers 5 and 6
The pressure welding part 8 is pressed by the pressure of the convex part 7.7 in
The thickness t1 is set to be approximately 2096 times the thickness to before pressurization, and pressure contact portions 8 are formed at a plurality of locations in order to obtain electrical and mechanical bonding characteristics.

(Problems to be Solved by the Invention) In the above-described joining method, the upper and lower 5°6 convex portions 7, 7 are formed with inclined surfaces 7a, 7a, and the pressure welding portion 8
An inclined surface 8a is formed by the inclined surface 7a at the peripheral portion of the slanted surface 7a. In this case, if the inclination angle α of the inclined surface 8a becomes large, a large shearing force will be applied around the pressure contact portion 8, so the inclination angle α is set to about 45 degrees. However, in this case, the upper and lower types 56
When the pressure welding part 8 is pressurized by the pressure welding part 8, a flow occurs from the pressure welding part 8 to the surrounding area due to plastic deformation of the material of each metal member 1, 2.3. In addition, work hardening occurs in the pressure-welded portion 8, making it brittle, and therefore the strength of the pressure-welded portion 8 in the peeling direction is low. Moreover, such a drawback tends to become more pronounced when a combination of thin and thick metal members are to be joined, or when a large number of metal members are overlapped.

Therefore, an object of the present invention is to provide a cold welding method that can improve the fluidity of the material from the welded part to the peripheral part due to the plastic deer shape when pressurized by a mold, and that can prevent a decrease in strength in the peeling direction at the welded part. is to provide.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a cold pressure welding method in which a plurality of metal members are overlapped and joined by partially applying pressure to the overlapped portion with a mold, in which the above-mentioned method is provided. A feature of the metal member is that four parts are formed around the part of the metal member that is pressed by the pressurization of the mold.

(Function) According to the above-mentioned means, when the overlapping portion of the metal members is pressurized by the mold, the material that is in the metal member and flows from the press-welded portion to the surrounding area due to plastic deformation enters the recessed portion. This improves the fluidity of the material. Thereby, it is possible to suppress work hardening of the material in the pressure-welded part, preventing it from becoming brittle, and it is possible to prevent a decrease in strength in the peeling direction at the pressure-welded part.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

First, in FIG. 1, reference numerals 11 and 12 are an upper mold and a lower mold, respectively, which are arranged opposite to each other without having an uneven shape.
An inclined surface 13a having an angle of about 45 degrees is formed around the periphery of the slanted surface 13a. Reference numerals 14 to 18 designate a plurality of metal members, in this case five metal members, which are stacked one on top of the other with the oxide film on the surface removed in advance with a wire brush. Among these five metal members 14 to 18, in this case, the upper, middle, and lower metal members 14, 16.18 are made of aluminum plates, and the remaining metal members 15.17 are made of aluminum. and the lower metal members 14 and 18 are thicker and the other metal members 15
, 16.17 is thinner than that. And on the surface of each upper, middle and lower metal part +414.16.18,
A plurality of recesses 19 are formed in advance in the shape of j[β by cutting, for example, at portions corresponding to the peripheral portions of the convex portions 13 of the upper and lower molds 11 and 12.

In order to join the metal members 14 to 18, the metal parts 1414 to 18 are overlapped, and the overlapped portions 20 are placed so that the recesses 19 are around the protrusions 13. It is placed between the mold 11 and the lower mold 12, and in this state, the overlapping portion 2 is cut by the upper and lower molds 11 and 12.
Pressure 0.

As a result, the overlapping portions 20 are joined as shown in FIG. In this case, the pressure is applied so that the thickness dimension T1 of the pressure contact portion 21 pressed by the pressure of the convex portions 13.13 becomes approximately 20°6 of the thickness dimension To before IJII pressure.

Here, when the pressure welding part 21 is pressurized by the convex part 13.13 of the top, Senryo' 4211.12, the material of the pressure welding part 21 flows to the peripheral part by plastic deformation, and the material flows into each of the four parts 19. Since the material enters the inside and fills the four parts 19, the fluidity of the material improves by the amount that the flowing material can enter the four parts 19, and the material is work-hardened in the pressure welding part 21. can be suppressed and good bonding can be performed.

In the above-described embodiment, five metal members are overlapped and bonded together, but the number of metal members is not limited to five, and it goes without saying that a plurality of metal members may be used. Furthermore, although an aluminum plate and a copper plate are used as examples of metal members, it is also possible to use only an aluminum plate or only a copper plate, or even a metal other than an aluminum plate or a copper plate.

[Effects of the Invention] As is clear from the above description, the present invention provides a cold pressure welding method in which a plurality of metal members are overlapped and joined by partially pressurizing the overlapping portion with a mold. By forming a recess around the part of the metal member that is pressed by the pressurization of the mold, when the overlapped part of the metal member is pressurized by the mold, the part of the metal member that is pressed by the mold is pressed. The material that flows toward the periphery due to plastic deformation enters the recessed portion, thereby improving the fluidity of the material. This has the excellent effect of suppressing work hardening of the material in the pressure-welded part, preventing it from becoming brittle, and preventing a decrease in strength in the peeling direction at the pressure-welded part.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, FIG. 1 is a longitudinal sectional view of the metal member in a state before being pressurized, and FIG. 2 is a longitudinal sectional view of the metal member in a state after being pressurized. . Also, the third
FIGS. 1 and 4 are views corresponding to FIGS. 1 and 2, respectively, showing a conventional example. In the drawings, 11 is an upper mold, 12 is a lower mold, 14 to 18 are metal members, 19 is a recessed portion, and 21 is a pressure contact portion. Agent Patent Attorney Nori Ken Chika Yudo Kendai Maru 2 Figure 4

Claims (1)

[Claims] 1. In a method of joining a plurality of metal members by overlapping them and applying partial pressure to the overlapping portion with a mold, the metal member is bonded to the surrounding area of the part of the metal member that is pressed by the pressure of the mold. A cold pressure welding method characterized by forming a recess.