JPH0125452Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field The present invention relates to a composite electrical contact material generally represented by a crossbar contact.

This type of composite electrical contact material is used in the medium current region rather than the micro current region, and has gold or gold alloy on the surface, silver or silver alloy in the middle, and the lower surface is where this electrical contact material is welded to the substrate. When used, it is made of nickel or a nickel alloy, and when used by caulking, it is made of copper or the like.

(b) Background of the invention In the above-mentioned types of composite electrical contact materials, the use of gold or gold alloy on the surface not only improves the contact stability of the contact, but also improves the contact stability of the contact, which is in the middle and essentially covers the contact surface of the contact. This is to prevent the silver or silver alloy from undergoing chemical changes such as sulfurization and chlorination.

In order to cover such silver or silver alloy contact surfaces with gold or gold alloy, plating and vapor deposition methods are often used. Another method is to clad gold or a gold alloy on the silver or silver alloy contact surface.

In the latter method, that is, the cladding method, the cladding surface of gold or gold alloy is rolled, so the thickness can only be at least about 5 μm, and the sides of the contact surface of silver or silver alloy cannot be covered. On the other hand, the former method, i.e., the plating method, is not only more advantageous than the latter method in terms of cost since it is possible to make the gold or gold alloy layer on the surface extremely thin when using the vapor deposition method. It has the advantage of being able to cover the entire contact surface of silver or silver alloy.

However, if a composite contact material in which gold or gold alloy is plated or vapor-deposited on the contact surface is made in the form of a long tape, it is used by cutting it into the desired length in a direction transverse to its longitudinal direction. The silver or silver alloy contact material will be exposed on the cut side surface. In a durability test under a severe sulfuric or chloride atmosphere, the side surface of the silver or silver alloy material that is exposed to the outside undergoes a chemical change, and if this surface becomes the tip of the chemical change, gold or gold alloy Even the surface is covered with a chemically altered layer.

(C) Disclosure of the Invention The present invention guarantees that in the above-mentioned types of composite electrical contact materials, especially tape-shaped contact materials, the sides of the silver or silver alloy are completely covered with gold or gold alloy. The present invention provides a composite electrical contact material that can be used.

In the present invention, for the above-mentioned purpose, on the top surface of the tape-shaped composite electrical contact material before the surface is covered with gold or gold alloy, each position where it is planned to be cut into a single electrical contact is provided. A groove with a depth reaching at least the bottom surface of the contact surface of silver or silver alloy is placed in the direction transverse to the long axis direction of the tape, and then this surface is coated with gold or gold alloy by plating method, vapor deposition method, etc. Thus, a coated composite electrical contact is provided.

The present invention is based on a tape-shaped crossbar composite contact material made of three layers of gold or gold alloy, silver or silver alloy, and nickel alloy. The present invention also provides a composite electrical contact material in which the gold or gold alloy that covers the contact surface of the silver or silver alloy is spread to form a notched wire and extend in the direction of the arrow until it reaches at least the bottom surface of the silver or silver alloy. be.

In this invention, it goes without saying that the above-mentioned arrowheads may be formed on the tape and the tape may be cut to the length of the desired single contact.

Next, embodiments of the composite electrical contact material according to the present invention will be described with reference to the accompanying drawings.

(D) Example First, the tape 1 of the crossbar contact shown in FIG. has protrusions at desired locations. Reference numeral 6 denotes an arrow-shaped notch provided in a direction transverse to the longitudinal direction of the tape 1 so as to reach at least the bottom surface of the silver or silver alloy layer 2 on the contact surface. The space between each adjacent cutout notch is such that the tape is finally cut and used as a single contact.

The composite electrical contact material of the present invention is obtained by plating or vapor depositing gold or a gold alloy on the silver or silver alloy layer 2 on the upper surface of the tape 1 having the above-mentioned notches.

Next, the present invention will be explained with reference to FIGS. 2 and 3.

The contact base 3 is similar to the tape 1 of FIG. 1, but the silver or silver alloy layer 2 on the contact surface is previously covered with gold or a gold alloy 4. In a direction transverse to the longitudinal direction of this tape 1, a notch is formed by being pressed in the shape of an arrowhead with a coining blade 7. In this case, the blade 7 has its tip reaching at least the bottom surface of the silver or silver alloy of the contact surfaces 4, 2, and the gold or gold alloy 4 covering the silver or silver alloy is spread out to the side surface of this arrow-shaped notch. Make sure to cover everything.

A single contact 1' shown in FIG. 3 is obtained by cutting the contact shown in FIG. 2, and the entire surface of the contact is covered with gold or gold alloy.

FIG. 4 is similar to FIG. 2, but shows a tape for making a rivet type contact, the base of which is made of copper or copper alloy for caulking.

(E) Effects of the invention As mentioned above, the entire surface of the silver or silver alloy layer forming the contact surface of the composite electrical contact material of the present invention is coated with gold or gold alloy, which prevents sulfidation, chloride, etc. It has an outstanding effect of protecting against chemical changes.

[Brief explanation of the drawing]

FIG. 1 is an explanatory perspective view of the material for making the tape-shaped composite electrical contact material according to the present invention, especially one having a base for spot welding, and FIG.
FIG. 3 is an explanatory perspective view similar to that of FIG. 3, the contact surface of which has been previously coated with gold or gold alloy; FIG. 3 is a single contact for spot welding obtained by cutting the tape of FIG. 2; FIG. 4 is an explanatory perspective view of a tape similar to that of FIG. 2 for obtaining a rivet-type contact for caulking. Description of symbols, 1... Tape, 2... Silver or silver alloy layer, 3... Base made of nickel alloy, etc., 4... Gold or gold alloy layer covering the contact surface, 5... Base for caulking made of copper, etc., 6 ...Archive-shaped notch, 7...Press blade piece.

Claims (1)

[Claims for Utility Model Registration] (1) It has a contact surface made of silver or silver alloy, gold or gold alloy covering it, and a protruding base for spot welding or caulking adhered to the lower surface of the contact surface. The tape material for electrical contacts has an arrow-shaped notch along the line to be cut in the direction transverse to the longitudinal direction of the tape material in order to make a single contact, and the tip of this notch is reaches at least the bottom of the contact surface of the silver or silver alloy, and the entire side surface of the notch is coated with the gold or gold alloy described above. (2) The arrowhead-shaped notch is formed before the contact surface is covered with gold or a gold alloy, and the gold or gold alloy is plated or vapor-deposited on the entire surface of the silver or silver alloy including the arrowhead-shaped notch. Composite electrical contact material according to claim 1, which has been registered as a utility model. (3) Scope of Utility Model Registration Claim 1, which is a tape material for the electrical contact, in which gold or gold alloy covering the contact surface is spread to cover the entire side surface of the arrow-shaped notch. Composite electrical contact material as described.