JPS5834889B2 - Setsutenoseizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an electrical contact using an Ag oxide metal.

In the conventional manufacturing method of bonding dissimilar materials to obtain electrical contacts, as shown in the manufacturing process in FIG. 1, an Ag plate 2 is crimped to one side of the contact raw material 1 to facilitate welding. One method is to use a plate material, punch out a tip 3 of a predetermined shape from the plate material, internally oxidize the tip 3, and then weld or braze it to the base metal 4 to obtain a contact point. There is a method in which a wire material that has been internally oxidized is used as a contact material, cut into a required length to form a chip 5, and then crimped and bonded to a base metal 6 to obtain a contact point.

However, in the above-mentioned sheet material punching method, a large amount of scrap is generated due to punching, the yield of the material is extremely low, the processing cost is high, and moreover, an unoxidized part 3' is generated in the center of the chip. This had the disadvantage of causing variations in product quality.

In addition, when using oxidized wire, a large furnace is required for oxidizing the wire, which increases equipment costs, and at the same time, the unoxidized part 5' generated in the center of the wire is located in the center of the product contact surface, so contact formation is difficult. Later, as the frequency of use increases, it becomes easier to weld, which has the disadvantage of decreasing functionality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a manufacturing method that eliminates various drawbacks of conventional manufacturing methods and provides a contact with excellent electrical properties such as welding resistance and arc resistance.

The method according to the present invention is characterized in that the unoxidized portion of the raw material after oxidation is utilized for the bonding surface.

Hereinafter, the method of the present invention will be explained step by step with reference to FIG.

The method of the present invention uses unoxidized wire rod 10a as a raw material,
This is cut into twice the required length by the cutter 11 to obtain raw material chips 10b (FIG. 3A).

This raw material chip 10b is heated for a long time at 600 to 800°C in an oxidation furnace with an 02 atmosphere to promote internal oxidation, thereby obtaining an oxidized chip 10c (FIG. 3B).

In this case, as a necessary phenomenon of internal oxidation, the oxidized chip 10
The central part of c is unoxidized (hereinafter referred to as unoxidized part 10').

) part occurs. In the present invention, the unoxidized portion 1
0', and the cutter 12 cuts the longitudinal center portion of the oxidized chip 10c into the unoxidized portion 10.
' and cut into two parts (Fig. 3C), cutting tip 10d.
The cutting tip 10a, which has been cut into 0 pieces, naturally has a cut surface with an unoxidized portion 10', and the cut surface is bonded to the alloy here.

For example, when manufacturing a pot-shaped contact, as shown in FIG. 4, the cut surface of the cutting tip 10d is engaged with the tip of the rod-shaped base metal 13 (FIG. 4A), and the two are bonded together by cold crimping or welding. It is crimped (FIG. 4B) and then compression molded into the final shape using a concave die (FIG. 4C).

In addition, when forming a direct adhesive contact, the cut surface of the cutting tip 10d is engaged with the plate-shaped base metal 14 as shown in FIG. let

In the present invention, since the part of the cutting tip where no oxide is present is used to press the alloy to the
The same effect as when the AJ layer is included on the bonding surface is accompanied, and the adhesion between the contact and the base metal becomes extremely easy.

Further, in the method of the present invention, the unoxidized portion 10' of the chip
Since this method utilizes the oxide on the bonding surface and leaves no unoxidized portions on other parts, the entire contact will be in a state in which the oxide is sufficiently contained.

In general, the content of oxides and the change in hardness are almost proportional, and those with high hardness have excellent electrical properties, and this point also shows the advantages of the contacts according to the present invention. .

FIG. 6 is a graph showing a hardness comparison between a contact made by the method of the present invention (solid line a) and a contact made by the conventional method (dashed line and dashed-dotted line C1°C2), showing the hardness of the contacts at the same six points in each sample. The results are shown below.

According to this figure, the contact point (dotted line b) by the plate punching method
Although there is no change due to the difference in the measurement position between the center part I and the outer peripheral part (■), the hardness of the central parts B and B' in the thickness direction is the same as that of the contact surface A.

This value is extremely low compared to A' and the bonded areas c and c' between the contact and the alloy.

In the case of contacts made using oxidized wire (chain line C), there is no difference in hardness in the thickness direction, but there is a large difference depending on the measurement position. The hardness of C1) is extremely low.

On the other hand, in the case of the contact made by the method of the present invention (solid line a), there is no change in the measurement positions It can be seen that low hardness areas are only unevenly distributed in areas with low hardness.

According to the contact manufacturing method of the present invention, it is possible to manufacture a contact that maintains high electrical performance, it is easy to adhere to the alloy during manufacturing, the yield of contact material is high, and the processing cost is low. It is extremely effective as a method for manufacturing contacts, since punching and brazing can be provided at a cost as low as that of standard foil.

According to the method of the present invention, A that does not contain oxides at the boundary with the composite material
The J' alloy phase can remain.

Therefore, by further heat-treating the composite formed into the shapes shown in FIG. 4 C and FIG.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams of manufacturing processes using different conventional methods. 3 to 5 are explanatory diagrams of the manufacturing process according to the present invention. FIG. 6 is a diagram showing a comparison of the hardness of contacts manufactured by the method of the present invention and the conventional method. 10a... Raw material, 10b... Raw material chip, 10c... Oxidation chip, 10d...
...cutting tip, 10'...unoxidized part, 1
3.14...base money.

Claims (1)

[Claims] 1. Using a wire as the raw material for the contact, cutting the raw material to twice the required length, internally oxidizing the cut chip, and forming an unoxidized part in the center of the chip after oxidation. Cutting the chip into two parts by penetrating the part, joining the cut surface of the chip to the alloy and cold-pressing, brazing or welding the chip, and compressing the bonded part into the desired shape using a concave die after adhesion. A method of manufacturing a contact consisting of: