JPH0138327B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical contact, and more particularly to a method for manufacturing an electrical contact as a movable contact for a seesaw switch.

As shown in FIG. 1, an electric contact 1 serving as a movable contact for a seesaw switch has a flat central portion, left and right side portions that are gently bent downward in an L-shape, and has a short width in the front-rear direction.

Conventionally, in order to manufacture such an electrical contact 1, as shown in FIG. 2a, a composite contact strip material 4 is formed by joining strip contact materials 3 to both left and right sides of the lower surface of a strip base material 2 and forming it into a uniform thickness. As shown in Figure b, marks 5 are placed at regular intervals in the longitudinal direction of the center, and elongated holes 6 are bored in the left-right direction between the marks 5, and then both left and right sides of this composite contact strip 4 are pressed. Then bend it downward into an L-shape as shown in Figure c, and then open the elongated hole 6.
The electrical contacts 1 were obtained by cutting and extracting both ends in between.

However, in this manufacturing method, during bending, the composite contact strip 4 is not only supported by the rods 1a between the elongated holes 6, but also restrained by the rods 1a. Tensile stress is applied to the processed part,
Cracks are likely to occur. Furthermore, since the elongated holes 6 are punched out at equal intervals, a large amount of recovered material is generated, which is equivalent to the amount of product, resulting in a very poor yield.

For this purpose, the left and right sides of the composite contact strip material 4 shown in FIG. 2a are conventionally bent into an L-shape with a press so that the contact material side protrudes as shown in FIG. 3a.
Thereafter, this composite contact strip material 4' is sequentially cut to a predetermined size to obtain electrical contacts 1' as shown in FIG. 3b.

However, in this manufacturing method, burrs on the cut end of the electrical contact 1' are generated oppositely on both the upper and lower surfaces as shown in FIG. 4, which adversely affects contact between the contacts, so barrel polishing is necessary. Further, in mass production, the bent composite contact strip 4' cannot be wound into a coil. Furthermore, it is difficult to cut the bent composite contact strip 4' without sagging while maintaining dimensional accuracy.

The present invention has been developed in view of the above circumstances, and has a high yield rate, excellent productivity, no cracks at all, no burrs on the cut end of the contact contact area, good quality and high dimensional accuracy. It is an object of the present invention to provide a manufacturing method capable of making electrical contacts.

In the method for manufacturing an electrical contact of the present invention, as shown in FIG. 5a, a strip-shaped contact material 3 is bonded to at least both left and right sides of the lower surface of the strip-shaped base material 2 (or the entire lower surface may be used), and the strip-shaped contact material 3 is formed to have a uniform thickness. As shown in Figure b, the composite contact strip material 4 is placed at regular intervals in the central portion 4a in the longitudinal direction.
Cut the left and right sides 4b, leaving only the left and right sides, and at the same time bend them downward to make them symmetrically inclined.
As shown in FIG.
It is characterized in that it is gently bent into a letter shape and at the same time the central portion 4a is cut to obtain the electrical contact 1''.

In this way, the method for manufacturing electrical contacts of the present invention involves cutting the composite contact strip material at regular intervals, leaving only the center portion, and cutting both the left and right sides, and simultaneously bending it downward and tilting it. Since there is no beam and both left and right sides are free, when bent into a contact shape, no tensile stress is applied to both left and right sides, so the material flows easily and no cracks occur. In addition, when the left and right sides, which are the contact contact parts, are cut, burrs are generated on the cut ends, but when the contacts are bent into an L-shaped contact shape using a press, the burrs are eliminated and high-quality electrical contacts are created. can get. In addition, when bending the left and right sides into the contact shape, the center part is cut and burrs are generated.
Since this burr is located at a location that does not become a contact point, it does not pose any problem. Furthermore, when cutting the center portion, the contact contact portions on both the left and right sides do not sag, so that an electrical contact with high dimensional accuracy can be obtained.

Furthermore, the method for manufacturing electrical contacts of the present invention allows electrical contacts to be made continuously without drilling elongated holes as in conventional methods, so no recovered material is generated and the yield is 100%, making it extremely productive. It has good characteristics.

In addition, the method for manufacturing an electrical contact of the present invention is capable of mass production because the composite contact strip material is cut and simultaneously formed into a contact shape, and the unformed composite contact strip material can be wound into a coil.

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. 5a, a width of 3 mm is provided on both left and right sides of the lower surface of the band-shaped base material 2 made of brass with a width of 10.3 mm and a thickness of 0.5 mm.
Fig. b As shown in the figure, the central part 4a is spaced at 2.7 mm intervals in the longitudinal direction.
Cut the left and right sides 4b by 3.5mm, leaving 3.3mm left, and at the same time bend them downward to make them symmetrically inclined at 20 degrees.Next, as shown in Figure c, cut the left and right sides 4b, which were tilted, downward with a curvature of 2mmR. The wire was bent horizontally into an L-shape, and at the same time the central portion 4a was cut to obtain an electrical contact 1'' with a width of 9 mm and a length of 2.7 mm.

Conventional example As shown in Fig. 2a, the width is 4.35 mm on both sides of the lower surface of the band-shaped base material 2 made of brass with a width of 13 mm and a thickness of 0.5 mm.
A strip contact material 3 made of Ag-13w/o CdO with a width of 13 mm and a thickness of 0.2 mm is bonded to a composite contact strip material 4 of a width of 13 mm and a thickness of 0.5 mm, which is formed into a uniform thickness.
As shown in the figure, marks 5 are placed at 4.6 mm intervals in the center longitudinal direction, and a width of 12 mm is placed in the left and right direction between the marks 5.
A long hole 6 with a length of 1.9 mm is bored, and then the left and right sides of the composite contact strip 4a are bent downward into an L shape with a curvature of 2 mmR as shown in Figure c using a 4.8 mm press. After processing, both ends between the elongated holes 6 were cut and extracted to obtain an electrical contact 1 having a width of 9 mm and a length of 2.7 mm.

When we inspected the quality of 100 electrical contacts of the example and the conventional example obtained in this way, we found 28 defective products with cracks in the electrical contacts of the conventional example, but in the electrical contacts of the example. There were no defective products with cracks, and they were of good quality and had high dimensional accuracy.

As can be seen from the above explanation, according to the method for manufacturing electrical contacts of the present invention, it is possible to produce electrical contacts that do not generate cracks, have no burrs on the cut ends of the contact contact parts, are of good quality, and have high dimensional accuracy. There is an excellent effect that can be done.

In addition, the method for manufacturing electrical contacts of the present invention does not generate any recovered materials and has an extremely high productivity with a yield of 100%. Therefore, it is suitable for mass production and can replace conventional manufacturing methods. This can be said to be an innovative manufacturing method.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an electrical contact for a seesaw switch, Fig. 2 a, b, and c are diagrams showing the steps of a conventional manufacturing method for the electrical contact, and Fig. 3 a, b are further steps of a conventional manufacturing method. FIG. 4 is a perspective view of an electrical contact obtained by the method shown in FIG. 3, and FIGS. 5 a, b, and c are diagrams showing steps of the method for manufacturing an electrical contact according to the present invention. 1''... Electric contact obtained by the manufacturing method of the present invention, 2... Band-shaped base material, 3... Band-shaped contact material, 4...
...Composite contact strip material, 4a...center part, 4b...left and right side parts.

Claims (1)

[Claims] 1. A composite contact strip material formed to have a uniform thickness by joining strip contact material to at least both left and right sides of the lower surface of the strip base material is cut at regular intervals on both left and right sides, leaving only the center portion, and at the same time, cut downward. A method for manufacturing an electrical contact, which comprises bending the electrical contact so that it is symmetrically inclined, and then gently bending the inclined left and right sides downward into an L-shape, and simultaneously cutting the central part to obtain an electrical contact. .