JPH0131247B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to improvements in the method of manufacturing rivet-type composite electrical contacts. Traditionally, rivet-type electrical contacts were made by cutting a contact wire made of precious metal or its alloy to the required length and forming it into a rivet shape by header processing, but recently in order to save on expensive precious metals or their alloys. Then, a composite contact wire 1 consisting of a contact material 1a made of a noble metal or its alloy on the inside as shown in FIG. The cut piece 1' is formed by header processing to produce a rivet type composite electrical contact 2 having an oval rivet head 2a as shown in FIG. 1c. However, since this rivet type composite electric contact 2 is formed by header processing from the cut piece 1' all at once, the centers of the rivet head 2a and rivet leg 2b are misaligned, as shown in Fig. 2a, and the pedestal is If the contact is inserted into the contact mounting hole and caulked, there is a drawback that the contact position will shift, and the second
In addition to the fact that the centers of the rivet head 2a and rivet leg 2b are misaligned as shown in Figure b, the rim of the rivet head protrudes, making it difficult to form the rivet properly. In order to eliminate this drawback, conventionally, the cut pieces 1' were not headered all at once, but were first inserted into the die 3 as shown in FIG. The upper part is expanded outward by pressing, and then the upper part is formed into a substantially trapezoidal cross section with a second preforming punch 5 as shown in FIG. 3b, and then with a finishing forming punch 6 as shown in FIG. 3c. The upper part was formed into an oval shape to obtain a rivet type composite electrical contact 2'. The thus obtained rivet type composite electrical contact 2'
The center of the rivet head 2a and rivet leg 2b does not shift, and the periphery of the rivet head 2a does not protrude, but since the area of the contact material 1a on the contact surface of the rivet head 2a is small, the contact performance is poor. There was a problem that it had a negative impact on The present invention was developed in view of the above circumstances, and it prevents the centers of the rivet head and rivet leg from shifting, and prevents the peripheral edge of the rivet head from protruding.
To provide a method for manufacturing a rivet-type composite electrical contact which is smooth without leaving marks, wrinkles, or unevenness, and which can expose contact material over the entire surface. The method for manufacturing a rivet-type composite electrical contact according to the present invention will be explained below with reference to the drawings. As shown in FIG. The cut piece 1' shown in FIG. 4b obtained by cutting the composite contact wire 1 consisting of Then, the upper end of the cut piece 1' is bitten into a fixed first forming punch 9 having a sharp conical protrusion 8, and the contact material 1a inside the upper end is expanded in the outer circumferential direction to form an inverted conical groove 10. form. Next, this cut piece 1' is pushed up slightly by the dowel pin 11 in the die 7, and the die 7 is moved up and down again, so that the upper end of the cut piece 1'
As shown in Figure d, the fixed second forming punch 14 having an arcuate protrusion 12 in the center and a ring groove 13 with an arcuate cross section on the outer periphery is punched in, and the inner contact material 1a is further expanded in the outer circumferential direction. arc-shaped groove 15
form. Next, this cut piece 1' is slightly pushed up by the notch pin 11 in the die 7, and the die 7 is moved up and down again, so that the upper end of the cut piece 1'
As shown in the figure, a fixed third forming punch 14' having a low arc-shaped protrusion 12' at the center and a ring groove 13' having an arc-shaped cross section on the outer periphery is punched into the fixed third forming punch 14', and the inner contact material 1a is slightly pushed in the outer circumferential direction. Crush it flat.
Next, insert this cut piece 1' into the dowel pin 1 in the die 7.
1, the die 7 is moved up and down again, and the upper end of the cut piece 1' is punched into the fixed fourth forming punch 17 having a hemispherical groove 16 as shown in FIG. Form into. Thereafter, this cut piece 1' was pushed up slightly by the dowel pin 11 in the die 7, and the die 7 was moved up and down again to form an oval groove 18 in the hemispherical upper end as shown in Fig. 4g. A fixed fifth forming punch 19 is inserted into the contact to obtain a rivet-type composite electrical contact 2'' having an oval-shaped rivet head 2a.As described above, the method for manufacturing a rivet-type composite electrical contact of the present invention has a method of manufacturing a rivet-type composite electrical contact with a precious metal or Contact material 1 of the alloy
A base material 1 of base metal or its alloy is placed on the outside.
The cut piece 1' obtained by cutting the composite contact wire 1 having the wires 1 to a required length is inserted into the die 7, and the cut piece 1' is gradually inserted into the knock pin by an amount corresponding to the amount of processing. 11, the contact material 1a on the inside of the upper end is bitten into the first to fifth forming punches and expanded and crushed in the outer circumferential direction to form the base material 1 on the outside of the upper end.
Since the base material 1b made of base metal or its alloy is not exposed on the contact surface of the rivet head 2a, only the contact material 1a is exposed, so that the contact performance is not adversely affected. Also, composite contact wire 1
The cut piece 1' obtained by cutting the rivet head 2a to the required length is gradually preformed in stages.
A highly accurate rivet-type composite electric contact 2'' can be obtained without the center of the rivet leg 2b shifting.Next, in order to clarify the effects of the method for manufacturing a rivet-type composite electric contact according to the present invention, its specific details will be explained. An example and a conventional example will be explained.Example As shown in Fig. 4a, an Ag contact material 1a with a diameter of 0.6 mm is placed on the inside and a Cu base material 1b with a diameter of 0.96 mm is placed on the outside.
The cut piece 1' shown in Fig. 4b obtained by cutting the composite contact wire 1 consisting of
As shown in the figure, the die 7 is inserted into a die 7 having a diameter of 1 mm, and thereafter the die 7 is moved up and down intermittently, and the cut piece 1' is pushed up step by step with the notch pin 11 in the die 7 by an amount corresponding to the processing amount. Meanwhile, the contact material 1a on the inside of the upper end is fixed with the first to fifth forming punches 9, 14, 14', 17, 19 shown in FIGS. 4c to 4g.
The contact material 1a has a diameter of 2.0 mm, a height of 0.7 mm, and a thickness of 0.5 mm, as shown in Fig. 4g.
mm oval rivet head 2a and diameter 1.0 mm,
A rivet-type composite electrical contact 2'' having a rivet leg portion 2b with a height of 1.2 mm was obtained. Conventional Example 1 As shown in Fig. 1a, an Ag contact material 1a with a diameter of 0.6 mm was arranged on the inside and a diameter of 0.96 mm on the outside. Cu base material 1b
The composite contact wire 1 consisting of the above-mentioned composite contact wire 1 is cut into a length of 2.93 mm as shown in Fig. 1b, and this cut piece 1' is formed by header processing to have a diameter as shown in Fig.
2.0mm, height 0.7mm oval rivet head 2
A rivet type composite electrical contact 2 having a diameter of 1.0 mm and a rivet leg portion 2b of 1.2 mm in height was obtained. Conventional Example 2 A cut piece 1' obtained by cutting the composite contact wire 1 into a length of 2.93 mm was inserted into a die 3 as shown in FIG. The upper part is expanded outward by pressing, and then the upper part is formed into a substantially trapezoidal cross section with a second preforming punch 5 as shown in FIG. 3b, and then with a finishing forming punch 6 as shown in FIG. 3c. The upper part was formed into an oval shape to obtain a rivet type composite electrical contact 2'. Examples thus obtained and conventional examples 1 and 2
When we tested the quality of 100 rivet-type composite electrical contacts, we obtained the results shown in the table below.

[Table] As is clear from the table above, the riveted type composite electrical contacts of the example have no defective products as seen in the riveted type composite electrical contacts of conventional examples 1 and 2, and are of extremely high quality. It can be said to be an electrical contact. In the example, the composite contact line of a round wire was obtained, but the present invention is not limited to this, and a square wire may also be used. Further, in the embodiment, the forming punch is fixed and the die is movable, but the present invention is not limited to this, and the die may be fixed and the forming punch is movable. As detailed above, according to the method for manufacturing a rivet-type composite electrical contact of the present invention, a rivet-type composite electrical contact can be produced in which there is no misalignment of the centers of the rivet head and the rivet leg, and the periphery of the rivet head does not protrude. can be obtained. Therefore, when this is inserted into the contact mounting hole of the base and caulked, the contact position will not shift. Further, since the contact material can be exposed over the entire contact surface of the rivet head, there is an excellent effect that a rivet type composite electrical contact with good contact performance can be obtained.

[Brief explanation of drawings]

Figures 1a, b, and c are cross-sectional views showing the steps of a conventional rivet-type composite electrical contact manufacturing method, and Figures 2a,
b is a cross-sectional view showing the defects of the rivet-type composite electrical contact obtained by the manufacturing method shown in FIG. 1, and FIGS. 3a, b, and c are cross-sectional views showing the steps of another conventional method for manufacturing a rivet-type composite electrical contact. Figures 4a-g
1A and 1B are cross-sectional views showing steps of a method for manufacturing a rivet type composite electrical contact according to the present invention. 1...Composite contact wire, 1a...Contact material, 1b...
...Base material, 1'...Cut piece, 2''...Rivet type composite electrical contact, 2a...Rivet head, 2b...
Rivet leg, 7...Dice, 8...Conical projection, 9...Fixed first forming punch, 10...Inverted conical groove, 11...Knock pin, 12...Circular projection, 13, 13 ′...A ring groove with an arc-shaped cross section,
14...Fixed second forming punch, 14'...Fixed third forming punch, 15...Circular groove, 16...Semispherical groove, 17...Fixed fourth forming punch, 18...
... Oval groove, 19 ... Fixed fifth forming punch.

Claims (1)

[Claims] 1. Cut a composite contact wire consisting of a contact material made of precious metal or its alloy on the inside and a base material made of base metal or its alloy on the outside to the required length, insert it into the die, and gradually push up the dowel pin. The upper end is formed into an inverted cone-shaped groove, then an arc-shaped groove, and then the groove is crushed slightly flat and expanded from the inside toward the outer circumference, and the inner contact material is attached to the outer base. A method for manufacturing a rivet-type composite electrical contact, characterized by forming a rivet head by covering the material.