JPH0528454B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for manufacturing electrical contacts used in electromagnetic contactors and the like.

[Conventional technology]

Traditionally, non-oxide materials such as Ag and Ag-Ni have been used as contact materials for electrical contacts in this field.
Oxide-based materials such as Ag-CdO and Ag- _SnO2 are known. Among these, non-oxide materials have good bonding properties with the contact base metal that supports the contacts, and therefore the contact can be joined to the base metal using resistance welding, which is efficient in manufacturing. With the cross section of the tip pressed against the base metal surface, electricity is applied to the contact part, and the heat generated at the contact part due to contact resistance melts and joins the bonding material to the base metal, after which one contact is left on the base metal side. It is possible to adopt a method of continuously repeating the process of cutting the contact material. However, on the other hand, non-oxide materials have drawbacks such as poor adhesion resistance and abrasion resistance during current switching, and a short lifespan. On the other hand, although oxide-based materials have excellent electrical switching performance, it is extremely difficult to bond directly to the base metal, so it is necessary to prevent the bonding surface of the contact material from oxidizing, or use other non-oxide materials. It is necessary to provide a non-oxide layer depending on whether the materials are bonded in advance or the like. Moreover, when joining to the base metal, it is necessary to braze the joining materials one by one, making it impossible to use the efficient resistance welding method described above.

[Problems to be solved by the invention]

In this way, conventionally, if we tried to adopt an efficient manufacturing method of continuous resistance welding of linear contact materials, we had no choice but to use non-oxide materials with poor electrical performance. In order to use oxide-based materials with good physical performance, there was a problem in that an inefficient manufacturing method had to be used. An object of the present invention is to provide a method for manufacturing an electrical contact that can obtain an electrical contact with excellent electrical performance by using both types of materials in combination to exhibit their respective characteristics and employing an efficient manufacturing method. The purpose is to

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention constructs a linear contact material by attaching an outer sheath made of a non-oxide material to a wire rod made of an oxide material, and shears this contact material through the outer sheath. At this time, by plastically deforming the outer skin, a film of non-oxide material is formed on the sheared surface of the oxide material, and the wire of the oxide material is joined to the contact base via this sheared surface. do.

[Effect]

According to this invention, since the wire made of oxide material to be joined to the base metal has a coating of non-oxide material formed on its sheared surface, it can be easily and firmly joined to the base metal, Furthermore, since the contact body is made of oxide-based material, electrical performance is also ensured.

【Example】

Embodiments of the present invention will be described below based on the drawings. In FIG. 1, numeral 1 denotes a wire-shaped composite contact material, which has a circular cross section as shown in FIG. It is composed of Reference numeral 4 denotes a pair of cutters placed on both sides of the bonding material, which shear the contact material 1 through the outer skin 3 by moving forward in the direction of arrow P. As shown in the figure, the cutting edge of the cutter 4 has a triangular cross section with an inclined upper surface and a horizontal lower surface. Therefore, when the bonding material is sheared, the outer skin 3 is plastically deformed to form a coating 5 of a non-oxidizing material on the sheared surface of the wire 2. Fig. 2 shows that power is applied between the bonding material 1 and the base metal 6 while applying force in the direction of arrow Q to press the sheared surface with the base metal 6, and the bonding material 1 is moved to the base metal based on heat generated by contact resistance. 3 shows the welded state. In this case, coating 5
If this does not exist, sufficient bonding strength to maintain electrical switching performance cannot be obtained. Figure 3 shows the state in which the welded contact material is sheared with the cutter 4, leaving one contact 7 on the base metal 6 side, and the sheared surface on the contact material 1 side is newly coated with a non-oxide material. 5a is formed and prepared for the next operation. These steps are then repeated. FIG. 4 shows the state shown in FIG. 3, with contacts 7 formed as necessary. Figure 6 shows a linear contact material 8 used in this invention.
This shows a different embodiment in which an outer sheath 10 made of a non-oxide material is attached to both sides of a wire 9 made of an oxide material having a square cross section by cold pressure welding or hot pressure welding. Shearing by the cutters is carried out through the skin 10 from both sides. The skin 10 may be unilateral depending on the required welding strength. Other suitable modifications are conceivable as long as a necessary and sufficient coating of non-oxide material is formed.

【Effect of the invention】

In this invention, by shearing a wire-shaped composite contact material in which a wire made of an oxide material is coated with a sheath made of a non-oxide material through the sheath, non-oxide By forming a film of the material, it is possible to use an oxide material with excellent electrical performance while continuously resistance welding the linear contact material to the alloy in the same way as with non-oxide materials. method can be adopted. That is, according to the present invention, manufacturing efficiency can be improved by easily automating the manufacturing of contacts while satisfying the electrical switching performance and sufficient bonding strength of the contacts.

[Brief explanation of the drawing]

1 to 3 are schematic explanatory diagrams of the process of the method of the present invention, and FIG. 1 shows the contact material in a sheared state, and the second
The figure shows a state in which the contact material is joined to the base metal, and FIG. 3 is a longitudinal sectional view showing the state in which the contact material is sheared, leaving one contact on the base metal side. FIG. 4 is a side view showing a molded state of the contact in FIG. 3, and FIGS. 5 and 6 are perspective views showing mutually different embodiments of the contact material used in the present invention. 1: Composite contact material, 2: Wire of oxide material,
3: Outer skin of non-oxide material, 4: Katsuta, 5,5
a: Non-oxide material coating, 6: Contact base metal.

Claims (1)

[Claims] 1 A wire made of an oxide material is coated with an outer skin of a non-oxide material to form a linear contact material, and when the contact material is sheared through the outer skin, the outer skin is plastically deformed to form an oxide material. A method of manufacturing an electrical contact, comprising: forming a film of a non-oxide material on a sheared surface of a sheared material, and joining a wire made of an oxide material to a contact base via the sheared surface.