JPH0410689B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a contact for a switch.

In general, contact alloys made using the powder sintering method are made from powders of several types of metals or intermetallic compounds, which are thoroughly mixed using a mechanical method, then stamped under a predetermined molding pressure, and then sintered in a high-temperature atmosphere. made and made. The contact alloy thus obtained is processed into a predetermined shape and then used by being bonded and fixed to a base metal made of a highly conductive material such as copper.

By the way, as a method of attaching the contacts to the alloy,
Cu-Ag in hydrogen atmosphere or vacuum
Hard soldering using Cu-Au based brazing filler metals is common. In the case of hard solder and alloys that have poor bondability, the most economical method for improving bondability is to place the contact molded body on a disc-shaped base made of copper conductive material such as powder molding. At the same time, the contact material is sintered at the high temperature normally used for sintering in a hydrogen atmosphere.
There was a two-layer structure type contact bonded to the base metal through a contact reaction. A two-layer contact constructed by this method is shown in FIG.

FIG. 1 is a side sectional view of a two-layer structure type contact constructed by a conventional method for manufacturing a switch contact. In FIG. 1, 1 is a contact material, and 2 is a base metal made of a disc-shaped plate made of copper or the like. During normal powder molding,
Contact material 1, which is a mechanically sufficiently mixed contact powder mixture of predetermined components, is placed on the main surface of a disc-shaped base metal 2 made of copper or the like, and is stamped to form a two-layered material as shown in FIG. This constitutes a molded body of a structural type contact before sintering. In this case, the contact material 1 and the base metal 2 are not firmly adhered, and the peripheral vertical portion 1a of the contact material 1
This prevents the contact material 1 from peeling off from the base metal 2 during the work steps up to sintering.

Among the conventional contact materials 1, for example, in the case of a contact material such as Bi ₂ O ₃ that contains 10% or more of a non-adhesive metal oxide, a two-layer structure contact is used as shown in Figure 1. Due to the poor adhesion between the contact material 1 and the base metal 2 after forming the molded body before sintering, if it is subjected to external mechanical shock, especially in the direction of arrow A, the contact material 1 and the base metal 2 will not adhere properly until sintering. Contact material 1 during the work process
The problem was that it easily peeled off from the base metal 2. In addition, in such a contact material 1, since the contact material 1 itself is fragile, the peripheral vertical portion 1a must be made uniformly thick, and the base metal 2 must be precisely set in the center of the molding die. .

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by providing a collar or a protrusion concentrically with the base metal 2 at the lower part of the outer periphery of the base metal 2 to support the peripheral vertical portion 1a. , the adhesive strength between the contact material 1 and the base metal 2 is increased, and the peripheral vertical portion 1a is
The object of the present invention is to provide an economical method for manufacturing a switch contact, which can uniformly reduce the thickness of the contact.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a side sectional view of a two-layer structure type contact constructed by the method for manufacturing a switch contact according to the present invention. In the figure, parts corresponding to those in FIG. 1 are given corresponding symbols. In FIG. 2, the base metal 2A includes a disk-shaped main base metal part 2a, and is provided concentrically with the main base metal part 2a at the lower part of the outer periphery of the main base metal part 2a, and supports the peripheral vertical part 1a of the contact material 1. It is provided with a flange portion 2b. Note that the thickness of the peripheral vertical portion 1a is shown enlarged from the actual thickness.

In this invention, since the base metal 2A is provided with the flange portion 2b, even if the contact material 1 is a contact material containing 10% or more of a non-adhesive metal oxide such as Bi ₂ O ₃ , the following description will be made. Contact material 1
No peeling occurs between the base metal 2A and the base metal 2A. That is, after the contact material 1 and the base metal 2A are molded by embossing, the contact material 1 is held on the main base metal part 2a of the base metal 2A by the peripheral vertical part 1a, and the peripheral vertical part 1a
It is supported by the collar portion 2b. Therefore, even if the contact material 1 is subjected to an external mechanical shock in the direction of arrow A until sintering, the contact material 1 will not peel off from the base metal 2A during the work steps up to sintering. Also, the main base metal part 2
By providing the flange portion 2b concentrically with a, the thickness of the peripheral vertical portion 1a becomes the same in the circumferential direction, and when sintered, the contact material 1 contracts uniformly and is bonded to the base metal 2A. Ru.

Therefore, even if the contact material 1 contains a metal oxide, has no adhesive properties, and is weak against impact, it can be easily molded into a molded body by embossing. In addition, the contact material 1 has adhesive material itself.
In this case, the thickness of the peripheral vertical portion 1a can be reduced, and the expensive contact material 1 can be saved.

FIG. 3 is a plan view showing another embodiment of the base metal used in the present invention. In Figure 3, base metal 2
B includes a disk-shaped main metal part 2a and a projection part 2c that is provided at the lower part of the outer periphery of the main metal part 2a and supports the peripheral vertical part 1a of the contact material 1. Note that the outermost part of the protrusion 2c is provided concentrically with the main base metal part 2a.

That is, the embodiment shown in FIG. 3 is provided with a projection 2c in place of the collar 2b of the embodiment shown in FIG. 2, and the effect is similar to that of the embodiment shown in FIG.

The base metals 2A, 2B and the electrode rod (not shown) can be easily connected by brazing, and the switch contact can also be easily connected to the electrode rod (not shown). Further, the flange portion 2b or the protrusion portion 2c may be provided at the center of the outer circumference of the main base metal portion 2a instead of at the lower portion of the outer circumference.

The present invention is made as described above, and includes a first step of placing the contact material 1 on the base metals 2A and 2B having the collar portion 2b or the protrusion portion 2c at the lower outer periphery of the disc-shaped main base metal portion 2a; It consists of a second step of forming a molded body by stamping after that, and a third step of sintering the molded body formed in the second step.
Since the flange portions 2b and protrusions 2c are provided on A and 2B, the contact material 1 does not peel off from the base metals 2A and 2b due to external mechanical shocks up to sintering. In addition, the collar portion 2b or the protrusion portion 2
Since the contact point c is provided concentrically with the main base metal portion 2a, the outer peripheral vertical portion 1a of the contact material 1 can be made thinner, and the expensive contact material 1 can be saved.

As described above, the present invention has various effects such as being strong against external mechanical shocks during the manufacturing process, saving contact materials, and being manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a two-layer structure contact constructed by a conventional method for manufacturing a switch contact, and FIG. 2 is a side sectional view of a two-layer structure contact constructed by a method for manufacturing a switch contact according to the present invention. The side sectional view and FIG. 3 are plan views showing other embodiments of the base metal used in the present invention. In the figures, corresponding parts in each figure are given corresponding symbols, 1 is the contact material, 1a is the peripheral vertical part, 2A, 2B are the base metal, 2a is the main base metal part, 2b
2c is a flange and a protrusion.

Claims (1)

[Scope of Claims] 1. A contact material to be sintered is placed on a base metal having a flange or a protrusion concentrically with respect to the main base metal part on the lower outer periphery of a substantially disc-shaped main base metal part. a first step of placing a powder mixture of the contact material and the base metal together so that the peripheral vertical portion of the contact material is supported by the collar portion or the projection portion; A method for manufacturing a switch contact, comprising: a second step of configuring a partially covered molded body; and a third step of sintering the molded body.