JPS6144371B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an improvement in a method for manufacturing an electric contact, in which an electric contact is formed by stamping a clad wire piece obtained by cutting a clad wire.

(Prior art) Conventionally, as shown in FIG. 1, a metal 1 for electrical contact such as a special metal such as gold or silver is pasted on one or both longitudinal sides of a strip-shaped conductive base metal material 2 such as copper. A clad wire piece a that is cut from the end of the so-called clad wire A so as not to produce chips.
A columnar preformed material 6a was formed using a die 3 and punches 4 and 5 as shown in FIG. 2, and a contact portion made of the electrical contact metal 1 was integrally formed on the top of the material by stamping. Methods of manufacturing electrical contacts are known.

This conventional method is advantageous in that it does not produce any special precious metal chips used as the contact material, and the process is simplified because the contact material is pasted in advance.

(Problems to be Solved by the Invention) In this conventional method, a square clad wire piece a is pressed or molded into a preformed material 6a in the shape of a cylinder, hexagon, octagon, etc. using a punch and die. When forming the wire, the square part of the cylindrical prismatic clad wire piece a moves in a direction perpendicular to the pressing direction by the punches 4 and 5, that is, toward the end surface of the clad wire piece a, as shown in FIG. 3A. It protrudes in a wavy manner.
After that, the end surface comes into contact with the dies 3, 3, and as shown in FIG.
is formed.

Therefore, in the preformed material 6, the boundary C between the contact metal material 1 and the conductive base metal material 2 has a wavy shape, and the contact metal material 1 is further arranged at the contact part as shown in FIG. Rivet-like contact 6b
If the wavy pattern is formed on the boundary C', the wavy pattern of the boundary C' becomes even larger, and only the wavy pattern part does not function as the desired electrical contact. Therefore, in order to obtain a sufficient function, it is necessary to It is necessary to assume this in advance and use a large amount of expensive contact metal material 1, which inevitably makes the electrical contacts formed expensive.

In view of these points, the present invention provides that when forming an electrical contact in a desired shape by pressing or stamping a clad wire piece obtained by cutting a clad wire material into a desired shape, a contact metal material and a base metal material are used. The purpose of this product is to provide a processing method that allows the boundary line to have extremely small waves compared to conventional products, to minimize the use of expensive metal materials for contacts, and to reduce prices. be.

(Means for Solving the Problems) The gist of the present invention is to solve the above-mentioned conventional problems and achieve the intended purpose. A square prism-shaped clad wire piece having the metal layer for electrical contact on the end face by cutting a clad wire in which a metal layer for electrical contact is pasted on one side or both sides at mutually symmetrical positions in a direction perpendicular to the longitudinal direction of the clad wire. In the method of manufacturing an electrical contact, the clad wire piece is formed into a desired electrical contact shape by pressing or forging, in which the clad wire piece is formed so that the length between its two end faces does not become long. With the distance between the end faces regulated, the surrounding surfaces excluding both end faces are pressurized with a movable punch to form the entire preformed material into a cylindrical shape or a prismatic shape closer to a cylindrical shape than the original square prism, and then press. Or by Kazuzo,
The method of manufacturing an electric contact is characterized in that the electric contact is formed into an electric contact having a contact portion having a circular cross section substantially concentric with the axis of the preformed material.

The electrical contact metals used include precious metals such as gold and silver, precious metal alloys, precious metal-containing alloys, and other oxides, and the conductive base metals include iron, copper, nickel, and alloys thereof. Alloys containing them are typical, and sometimes silver, palladium, etc. are also used.

Furthermore, compared to metal materials for contacts, clad wire rods use cheaper metals as base metal materials,
These tension materials may be externally plated, and the joining method may be brazing, welding, or pressure welding, and the shape of the clad wire piece may be the same as the metal material for electrical contacts. It may be cut so that the interface with the base metal material is not wavy, and it can be formed into various shapes.

(Function) This method of manufacturing an electric contact is to produce a square pillar-shaped clad wire piece by applying pressure to the surrounding surfaces while regulating the distance between both end faces so that the length of both ends of the clad wire piece does not become too long. The metal material of the base metal material is prevented from moving toward the end face side, and is moved in the circumferential direction and deformed into a cylindrical shape or a state close to this, which reduces waving at the boundary between the base metal material and the electrical contact metal. .

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

First, the first embodiment will be explained with reference to FIGS. 5 to 9. In the figures, reference numeral 10 is a clad wire piece obtained by cutting a clad wire material in the same way as described above. This clad wire piece 10 is made of a base metal made of a copper strip. An electrical contact metal layer 12 made of gold is formed on one side of a material 11 with a silver layer 13 sandwiched between them.

As shown in FIG. 6, the rectangular prism-shaped clad wire piece 10 formed in this way is hit with immovable punches 14, 14 on the end face on the side of the electrical contact metal material layer 12 and the end face on the opposite side. A movable punch 1 moves around it while preventing it from being pushed out to both end faces.
5 and 15 to form an octagonal prism-shaped preformed material 16 shown in FIG.

Note that, before creating the octagonal prism-shaped preformed material 16, a multi-step process may be used in which a hexagonal prism is formed in the same manner while preventing the material from extending to both end faces, and then further formed into an octagonal prism.

The preformed material 16 thus formed is placed in a mold, and a cylindrical electric contact secondary material 17 is formed by regulating both end surfaces without increasing the length between the two end surfaces. Furthermore, as in the prior art, a rivet-type electrical contact 18 is formed by pressing or forging.

In this way, by going through the process of creating the preformed material and the secondary material while regulating the length between the end faces so as not to extend, an electrical contact with almost no wavy pattern appearing at the boundaries of each metal material. is obtained.

Next, the second embodiment will be explained with reference to FIGS. 10 to 12. In the figures, 10a is a clad wire piece;
This clad wire piece 10a is cut from a clad wire as described above, and has contact metal material layers 12a made of a cadmium oxide-silver alloy on both end surfaces of a base metal material 11 made of a copper strip.
This clad wire piece 10a is pressed down with a stationary punch and its periphery is compressed with a movable punch in the same manner as described above to form a cylindrical shape as shown in FIG. As shown in FIG. 12, the preformed material 16a is inserted into the hole 20 of the terminal plate 19, such as a leaf spring, and compressed from both ends to form contacts on both sides of the terminal plate 19. The contactor 18a is formed by arranging the contactor 18a.
Even in this case, by going through the process of forming the material while preventing it from extending in the direction of both end faces, almost no waves will appear at the boundary between the base metal material of the contact 18a and the contact metal material. molded.

(Effects of the Invention) The method for manufacturing an electrical contact of the present invention is configured as described above, and a clad wire piece in the shape of a rectangular prism made of a plurality of metal materials stacked is made so that the lengths of both end faces of the clad wire piece do not become long. By pressurizing the surrounding surfaces excluding both end faces while regulating the distance between the end faces to form a preformed material in a cylindrical shape or a prismatic shape close to this, the metal material at the corner part of the square prism, which has the largest deformation, is The movement of the cladding wire piece toward both end surfaces is prevented, and the peripheral flat surface side of the cladding wire piece acts in a bulging direction, thereby maintaining the flat state of the interface between each metal material. From this preformed material,
By molding a contact portion having a cross section that is concentric with the axis, it is possible to obtain an electrical contact in which the corrugations at the boundary between the contact metal layer and the base metal material are significantly smaller than in the past. It has become.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a clad wire rod and a clad wire piece, Figure 2 is a sectional view of the conventional processing method, Figure 3 A,
FIG. 4 is a perspective view of a contact formed by the same processing method, and FIG. 5 is a cladding wire used in the first embodiment of the present invention. FIG. 6 is a sectional view showing the same processing method, FIGS. 7 and 8 are perspective views of the preformed material, FIG. 9 is a front view of the manufactured contact, and FIG. 10 is a perspective view of the piece. FIG. 11 is a perspective view of a clad wire piece using the second embodiment, FIG. 11 is a perspective view of a preformed material, and FIG. 12 is a sectional view of a contact. A... Clad wire rod, 10, 10a... Clad wire piece, 11... Base metal material, 14... Fixed punch, 15... Movable punch, 16, 16a...
Preformed material, 17... Secondary material, 18, 18a
...Electrical contact, 19...Terminal board.

Claims (1)

[Claims] 1. A clad wire with a metal layer for electrical contact pasted on one longitudinal side of a base metal material made of a strip-shaped conductive material or on both sides at mutually symmetrical positions is cut in a direction perpendicular to the longitudinal direction, and the end face is coated with the A method for manufacturing an electrical contact, in which a rectangular prism-shaped clad wire piece having a metal layer for electrical contact is formed, and the clad wire piece is formed into a desired shape of an electric contact by pressing or forging, wherein the clad wire piece is ,
While regulating the distance between the end faces so that the length between the two end faces does not become too long, pressurize the surrounding surfaces excluding the two end faces with a movable punch to make the whole into a cylindrical shape or a cylindrical shape from the original square prism. An electrical contact characterized in that it is formed into a preformed material having a nearly prismatic shape, and then is formed by pressing or forging into an electrical contact having a contact portion with a circular cross section that is substantially concentric with the axis of the preformed material. Production method.