JPS6351327B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of manufacturing an electric contact embedded in a mold 3 as a fixed contact 2 for contacting a fixed contact such as a micro switch, for example, a movable contact 1 of a seesaw switch as shown in FIG. Conventionally, in order to make an electric contact used as a fixed contact of a seesaw switch, a composite contact strip 6 obtained by joining a contact strip 4 to a base strip 5 is cut and formed into a T-shaped cross section as shown in FIG. 2a. The base strip 7 is joined in the longitudinal direction at the center of the upper surface to form an electrical contact strip 9 with a cross-shaped cross section as shown in FIG. The contact strip material 4 is joined to the upper surface of the protruding strip of the irregularly shaped base strip material 8 provided with strips to form an electrical contact strip material 9 having a cross-shaped cross section as shown in FIG. A method of sequentially manufacturing electrical contacts 10 by punching a strip 9 from the side surface as shown in FIG. 2e, and a third method.
A composite contact strip 13 obtained by joining a contact strip 12 of the same width to the upper surface of a base strip 11 having a rectangular cross section as shown in FIG. A cross-shaped electrical contact strip 9' is made, and then this electrical contact strip 9' is press punched from the side in the same manner as shown in FIG.
There is a method of manufacturing 0. However, the former method shown in FIGS. 2a to 2e is extremely uneconomical as the contact material between one electrical contact 10 and the next electrical contact 10 becomes scrap due to the press punching process, resulting in a rise in the price of precious metals. . In addition, a composite contact strip 6 is attached to the irregularly shaped base strip 7 or 8.
Alternatively, in order to join the contact strip material 4, the feeding mechanism for the irregularly shaped base strip material 7 or 8 becomes complicated and large, and requires precision. Furthermore, since it is difficult to join the composite contact strip 6 or the contact strip 4 to the irregularly shaped base strip 7 or 8 with sufficient pressure, the bonding strength is low and unstable. Furthermore, the latter method shown in FIGS. 3a and 2b and FIG. 2e is uneconomical due to the soaring price of precious metals, as the contact material becomes scrap like the former method. In addition, since the contact strip material 12 is joined to the base strip material 11 having a large cross-sectional area, the contact strip material 12 and the base strip material 11 during welding are
The heat capacity was too different between the two and the heat generation balance was poor, and the bonding strength was weak and unstable. The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a method for manufacturing an electrical contact that does not cause scrap in the contact material and can maintain a high and stable bonding strength between the contact material and the base material. It is something to do. Hereinafter, the method for manufacturing an electrical contact according to the present invention will be explained with reference to the drawings. As shown in FIG.
As shown in FIG. The composite contact material 15 is made by cutting it to the required length as shown in Fig. 4c, and at the same time, it is separately cut into the required length as shown in Fig. 5a.
Base strip material 1 cut and formed into a T-shaped cross section as shown in
After forming a concave groove 17 in the longitudinal direction at the center of the top surface of the base material 18, the base material 18 is made by cutting to a required length as shown in FIG. 5b. The composite contact material 15 is inserted into the middle of the inside as shown in FIG. 6, and the electrical contact 19 is made by caulking. In this way, the method for manufacturing an electrical contact of the present invention involves inserting the composite contact material 15 into the groove 17 at the center of the upper surface of the base material 18 without finally pressure-welding the composite contact material 15 to the base material 18. However, since the joint is crimped and joined, the high joint strength between the contact material and the base material due to sufficient pressure welding between the contact strip material 4 and the base strip material 5 in the composite contact strip material 6 is maintained as is. It becomes something. In addition, since the composite contact material 15 cut to the required length is inserted into the middle of the groove 17 at the center of the upper surface of the base material 18, the electrical contact 1
9, the contact material is not scrapped and expensive precious metals are used effectively. Next, in order to clarify the effects of the method of manufacturing an electrical contact according to the present invention, specific examples and conventional examples thereof will be described. Example As shown in Fig. 4a, a contact strip 4 made of Ag with a width of 0.5 mm and a thickness of 0.8 mm was joined to a base strip material 5 made of Cu with a width of 0.5 mm and a thickness of 1.0 mm to obtain a width of 0.8 mm. mm, thickness
4b in the longitudinal direction at a height of 0.3 mm on both sides of the base strip 5 in the 1.4 mm composite contact strip 6.
After forming symmetrical V-shaped cut grooves 14 with a depth of 0.1 mm and a bevel angle of 60 degrees as shown in FIG. At the same time, as shown in Fig. 5a, the center of the upper surface of the base strip 16, which has a top side width of 2.0 mm, a top side thickness of 1.7 mm, a vertical side width of 0.8 mm, and a vertical side height of 4.0 mm, is cut and formed into a T-shaped cross section. After forming a concave groove 17 with a width of 0.81 mm and a depth of 0.6 mm in the longitudinal direction, a groove 17 with a length of 2.5 mm is formed as shown in Fig. 5b.
A base material 18 was prepared by cutting the base material 18 into pieces of mm, and then the composite contact material 15 was inserted into the middle of the groove 17 of the base material 18, as shown in FIG. 6, and crimped to form an electrical contact 19. Conventional Example 1 As shown in Figure 2a, a width obtained by joining a contact strip material 4 made of Ag with a width of 0.5 mm and a thickness of 0.8 mm to a base strip material 5 made of Cu with a width of 0.5 mm and a thickness of 1.1 mm. 0.6mm thickness 1.7
mm composite contact condition 6 is cut and formed into a T-shaped cross section and joined in the longitudinal direction of the center of the top surface of the base strip 7, which has a top side width of 2.0 mm, a top side thickness of 1.7 mm, a vertical side width of 0.8 mm, and a vertical side height of 4.0 mm. Then, as shown in FIG. 2b, an electrical contact strip 9 having a cross-shaped cross section is made.
As shown in FIG. 2e, the electrical contact 10 was made by punching from the side. Conventional Example 2 As shown in Fig. 3a, a contact strip material 12 made of Ag and having the same width and a thickness of 0.5 mm is bonded to the upper surface of a base strip material 11 made of Cu and having a rectangular cross section of 2.0 mm in width and 6.0 mm in height. The obtained composite contact strip 13 was cut on both the top, bottom, left and right sides as shown in Fig. 3b, so that the vertical sides had a width of 0.8 mm and a height of 0.8 mm.
An electrical contact strip 9' having a cruciform cross-section with a horizontal width of 2.0 mm and a horizontal thickness of 1.7 mm is made, and then this electrical contact strip 9' is inserted from the side as shown in Fig. The electrical contact 10 was made by press punching. However, the shear strength at the bonding surface between the contact material and the base material was measured for each of 100 electrical contacts 19 of these examples and 10 electrical contacts of conventional examples 1 and 2, and the yield from the material of the contact material was measured. Upon investigation, we obtained the results shown in the table below.

[Table] As is clear from the table above, electrical contact 1 of the example
It can be seen that in No. 9, the shear strength at the joint surface between the contact material and the base material is equivalent to that of the electrical contact 10 of Conventional Example 1, and higher than that of the electrical contact 10 of Conventional Example 2. Further, it can be seen that the yield of the contact material from the raw material in the electrical contact 19 of the embodiment is much higher than that of the electrical contacts 10 of the conventional examples 1 and 2. In addition, in the method of cutting and cutting electrical contacts of the present invention, if the composite contact material 15 and the base material 18 are chamfered, the composite contact material 1 will fit into the groove 17 of the base material 18.
5 is easy to insert. Further, when forming the grooves 17 in the base strip 16 having a T-shaped cross section, V-shaped cut grooves 20 may be symmetrically provided in the longitudinal direction of both upper side surfaces as shown in FIG. As detailed above, according to the method for manufacturing electrical contacts of the present invention, electrical contacts for use in fixed contacts such as microswitches can be easily produced without scraping contact materials, and expensive precious metals can be used effectively. Can be used for In addition, the composite contact material is not pressure welded to the base material, but is inserted into the groove of the base material and joined, so the bonding strength between the contact material and the base material is the same as that of the composite contact strip material and the base material. The high bonding strength due to sufficient pressure welding with the strip material is maintained as it is, and there are excellent effects such as obtaining an electrical contact with high and stable bonding strength.

[Brief explanation of drawings]

Figure 1 is a schematic sectional view of the seesaw switch, Figure 2
Figures a to e are diagrams showing the steps of a conventional manufacturing method of an electric contact used as a fixed contact of a seesaw switch, Figures 3a and b are diagrams showing a part of the process of the conventional manufacturing method, and Figure 4a Figures 5a to 6c are diagrams showing the manufacturing process of a composite contact in the method of manufacturing an electrical contact of the present invention, Figures 5a and b are diagrams showing the manufacturing process of a base material in the method of manufacturing an electrical contact of the present invention, and Figure 6
The figure shows the final step in the method of manufacturing an electrical contact of the invention, and FIG. 7 shows another example of the base strip used in the method of manufacturing an electrical contact of the invention. 4...Contact band material, 5...Base band material, 14...
Cut groove, 15...Composite contact material, 16...Base strip material, 17...Concave groove, 18...Base material, 19...
electrical contacts.

Claims (1)

[Claims] 1. In the composite contact strip material obtained by joining the contact strip material to the base strip material, cut grooves are formed on both sides of the base strip material and then cut to the required length to make the composite contact material, and at the same time Separately, a groove is formed in the center of the upper surface of a base condition with a T-shaped cross section, and then cut to a required length to make a base material.Then, the composite contact material is placed in the middle of the groove in the center of the upper surface of this base material. A method of manufacturing an electrical contact, characterized by inserting and crimping.