JPH0345848B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in a method for manufacturing a rivet-type electrical contact, and more particularly to an improvement in a method for manufacturing a rivet-type electrical contact whose lower end of the leg is chamfered.

(Prior Art) Conventionally, as shown in FIG. 1, in order to manufacture a rivet-type electrical contact 5 in which the peripheral edge of the lower end of the leg part 1 is chamfered 2 to facilitate insertion into the contact mounting hole 4 of the base material 3, the following steps have been taken: As shown in Fig. 2a, a solid or clad contact material 10 is inserted into the material insertion hole 9 of the die 8 whose bottom surface is formed by the upper end surface of the dowel pin 6 and a taper 7 is provided on the outer periphery of the bottom surface. As shown in FIG. 2b, the contact material 10 is preformed into a rivet shape using a header punch 11, and then, as shown in FIG. was.

(Problems to be Solved by the Invention) In this method of manufacturing a rivet-type electrical contact, there is a gap between the die 8 and the knock pin 6 as shown in FIG. 3a.
Since there is a clearance C of about 5μ, when the contact material 10 is preformed into a rivet shape as shown in FIG. 2b, a part of the contact material 10 enters the clearance C as shown in FIG. 3b, causing burrs. 13 occurs. Since the amount of plastic deformation is small at the time of this preforming, the burr 13 is small, but when the rivet-shaped electrical material 10' preformed as shown in FIG. 2c is finished formed into a rivet shape, the burr appears as shown in FIG. 3c. 13 becomes larger.

Such a burr 13 is a rivet type electrical contact 5.
When the base material 3 is polished, a foil-like covering is formed on the lower end surface of the leg 1 as shown in FIG. When used after installation, curling occurs, causing problems such as short circuits, constant ON status, and the burr 13 breaking off and entering the operating parts of the equipment, causing malfunctions.

(Objective of the Invention) The present invention was made to solve this problem, and the above-mentioned burrs are likely to occur because the clearance between the die and the knock pin is located at the position where the lower end of the contact material first spreads due to narrowing. Taking this into account, a rivet-type electrical contact is manufactured by locating the clearance away from the taper so that no material enters the clearance between the die and the knock pin.

(Means for Solving the Problem) The method for manufacturing a rivet-type electrical contact of the present invention includes the steps of manufacturing a rivet-type electrical contact in which the lower end of the leg is chamfered by header processing a solid or clad contact material. The header processing is performed by setting the material into the material insertion hole of the die, which has a small-diameter dowel pin arranged in the center of the bottom surface and is tapered around the bottom surface.

An embodiment of the method for manufacturing a rivet-type electrical contact according to the present invention will be described below with reference to FIGS. 5a to 5c.

(Embodiment) First, as shown in FIG. 5a, a material insertion hole 18 of a die 17 is provided with a small-diameter dowel pin 15 flush with the center of the bottom surface 14 and a taper 16 around the bottom surface 14.
A solid or clad contact material 10 is inserted and set, and then a header punch 11 as shown in FIG. 5b is inserted.
The contact material 10 is preformed into a rivet shape, and then, as shown in FIG.
was manufactured.

(Function) The burr 13 produced on the lower end surface of the leg portion 1 of the rivet-type electrical contact 19 manufactured in this manner is extremely minute and can hardly be discerned. This is because even though the clearance C between the die 17 and the dowel pin 15 is about 5μ as in the conventional case, the lower end of the contact material 10 is tapered and the clearance for the dowel pin is not located in the narrowed part, so the burr 13 is generated. This is because it is difficult.

(Other Embodiments) In the above embodiment, a small-diameter dowel pin 15 is disposed flush with the center of the bottom surface 14, and the material insertion hole 18 of the die 17, which has a taper 16 around the bottom surface 14, is made of solid or clad material. The contact material 10 was inserted and set and the header was processed, but the bottom surface 14 was not formed as shown in Fig. 6a.
The die 1 has a small-diameter dowel pin 15 protruding from the center of the die 1 and a taper 16 around the bottom surface 14.
The solid or clad contact material 10 may be inserted and set into the material insertion hole 18 of No. 7, and header processing may be performed in the same manner as in the previous embodiment. The rivet-type electrical contact 20 shown in FIG. 6b thus obtained is as follows:
Since the knock pin 15 is made to protrude and a recess 21 is formed in the center of the lower end surface of the leg 1, the burr 13 is formed on the lower end surface.
will not occur.

In addition, as shown in FIG.
The contact material 10 may be inserted and set into the material insertion hole 18 of the die 17 having a taper 16 around the periphery of the contact material 10, and header processing may be performed in the same manner as in the previous embodiment. The thus obtained rivet-type electrical contact 22 shown in FIG.
No burrs 13 are generated on the lower end surface.

Further, as shown in FIG. 8a, in the center of the bottom surface 14,
The contact material 10 is inserted into the material insertion hole 18 of the die 17, which has a small-diameter dowel pin 15 with a spherical tip surface 15a so that only the tip surface 15a protrudes, and a taper 16 around the bottom surface 14. Set it and
Header processing may be performed in the same manner as in the above embodiment. The thus obtained rivet-type electrical contact 24 shown in FIG. No burrs 13 are generated on the end face.

(Effects of the Invention) As can be seen from the above explanation, the method for manufacturing a rivet-type electrical contact of the present invention is to insert a solid or Since the clad contact material is set and header processed, the clearance between the die and the dowel pin is not located at the position where the lower end of the contact material first spreads, making it difficult for material to enter the clearance. An excellent effect is that a rivet-type electrical contact with almost no burrs on the end face can be obtained. In addition, when the rivet-type electrical contacts obtained in this way are polished, the minute burrs that appear on the lower end surfaces of the legs are worn away, so when they are inserted into the contact mounting holes of the base material and caulked as in the conventional case, When using the contacts after installation, there is no chance of the burrs peeling off, which prevents short circuits and turning on the device at room temperature. Since there is no problem, the cause of the failure can be eliminated.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a rivet-type electrical contact and the base material on which it is attached; FIGS. 2a to c are process diagrams showing a conventional method for manufacturing the rivet-type electrical contact shown in FIG. 1; FIG. a to c are enlarged views of part A in Fig. 2 a to c, respectively, and Fig. 4 is an enlarged view of part A in Fig. 2 a to c.
Figure 5 shows the state of burrs when a rivet-type electrical contact obtained by the manufacturing method shown in Fig. 5 is ground.
Figures a to c are process diagrams showing one embodiment of the method for manufacturing a rivet type electrical contact of the present invention, and Figures 6a, 7a, and 8a are process diagrams showing the method for manufacturing a rivet type electrical contact of the present invention. Vertical sectional views showing other examples of the die and knock pin used, FIG. 6b, FIG. 7b, and FIG. 8b
6A and 8B are longitudinal cross-sectional views showing rivet-type electrical contacts manufactured by header processing using the die and knock pins of FIGS. 6a, 7a, and 8a, respectively; FIG. 1... Leg, 2... Chamfer, 10... Solid or clad contact material, 11, 12... Header punch, 14... Bottom, 15... Knock pin, 15a
... Spherical tip surface of knock pin, 16 ... Taper, 17 ... Die, 18 ... Material insertion hole, 19,
20, 22, 24...Rivet type electrical contact, 21
...Concave portion, 23...Convex portion, 25...Spherical concave portion.

Claims (1)

[Claims] 1. In manufacturing a rivet-type electrical contact in which the lower end of the leg is chamfered by header processing of solid or clad contact material, the contact material is formed into a die with a small-diameter dowel pin in the center of the bottom surface and a tapered periphery of the bottom surface. A method for producing a rivet-type electrical contact, which comprises setting the contact into a material insertion hole and processing the header.