JPH0737463A - Manufacture of riveted electric contact point - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a riveted electric contact point, with which the difference in the diameters of the head parts of the riveted electric contact points is drastically reduced while the center displacement between the head part and the leg part can be restricted, and automatic caulking into a contact point mounting hole on a spring material can be carried out smoothly without interruption. CONSTITUTION:In manufacturing a riveted electric contact point, a columnar contact point material 3 is inserted into the inserting hole 2 of a die, for which a large diameter recessed part 0.2-0.6mm deep is formed concentrically on the opening peripheral part of the inserting hole 2 of the columnar contact point material. The head part of headed conical shape is preliminarily formed by a first punch 4, and then the head part of disc shape or mortar shape is finished and formed by means of a second punch whose flat front end surface is that or the second punch 26 provided with a recessed part 25 of conical trapezoid shape in the front end surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rivet type electrical contact, and more particularly to a method for producing a rivet type electrical contact suitable for automatically crimping a contact mounting hole of a spring material.

[0002]

2. Description of the Related Art A conventional rivet-type electrical contact manufacturing method is generally used in a die 1 as shown in FIG.
The cylindrical contact material 3 is inserted into the contact material insertion hole 2 of FIG. 3, and then the head 5 having the conical head shape is preformed by the first punch 4 as shown in FIG. As shown in FIG. 3c, the second punch 6 finish-molds the truncated cone-shaped head portion 7a to make the rivet-type electrical contact 8.

Recently, as shown in FIG.
A large-diameter concave portion 9 is provided at the peripheral edge of the contact material insertion hole 2 and the cylindrical contact material 3 inserted in the contact material insertion hole 2 is placed in the upper mold 10 in the concave portion 9 as shown in FIG. A disk-shaped head 11 is molded to form a rivet-type electrical contact 12. (As a prior art document, Japanese Patent Publication No. 4-7
5109).

By the way, in the former general method of manufacturing a rivet type electrical contact, as shown in FIG.
Due to the center deviation between the punch 6 and the die 1, a center deviation between the head portion 7a and the leg portion 7b of the rivet-type electrical contact 8 is 0.03 to 0.15 mm as shown in FIG. Since a taper is attached to prevent product adhesion, if the material volume is small, the lower edge of the head is rounded as shown in FIG. 7, the head diameter is small, and if the material volume is large, As shown in, a flash 13 is formed around the lower edge of the head.

Further, in the latter method of manufacturing a rivet type electric contact, since the upper die 10 is inserted into the large-diameter concave portion 9 provided in the opening peripheral edge of the contact material insertion hole 2 of the die 1, the concave portion 9 is formed.
The inner peripheral surface and the outer peripheral surface of the tip portion of the upper mold 10 are rubbed and worn, and a burr 14 is formed on the upper peripheral edge of the head of the obtained rivet-type electrical contact 12 as shown in FIG. Also, as shown in FIG. 10, foil-like fluttering 15 remains.

On the other hand, in the automatic crimping of the spring of the rivet type electric contact into the contact mounting hole, the rivet type electric contact is aligned and supplied by the parts feeder 16 as shown in FIG. It is sent into the contact mounting hole 19 of the hoop-shaped spring material 18 sent to the machine and caulked with the caulking die 20. If so, the feed amount of the rivet-type electrical contact seen from the foot portion changes each time, the leg portion does not enter the contact point mounting hole 19 of the spring member 18, and a catch occurs, and the automatic caulking is interrupted.

[0007]

Therefore, according to the present invention, the variation in the head diameter can be greatly reduced, and the center deviation between the head and the leg can be greatly suppressed, and the contact mounting hole of the spring member can be provided. It is an object of the present invention to provide a method of making a rivet-type electrical contact that can be smoothly performed without interrupting the automatic crimping.

[0008]

A method of manufacturing a rivet-type electrical contact according to the present invention for solving the above-mentioned problems includes a large diameter of 0.2 to 0.6 mm at a peripheral edge of an insertion hole of a cylindrical contact material. A cylindrical contact material is inserted into the insertion hole of a die having concavities formed concentrically, and then a conical head is preformed with a first punch, and then a second punch with a flat tip surface or It is characterized in that a disk-shaped or thin-shaped head is finish-molded by a second punch having a truncated cone-shaped recess on the tip surface.

[0009]

As described above, in the method of manufacturing a rivet-type electrical contact of the present invention, the head of the rivet-type electrical contact is provided in a recess having a depth of 0.2 to 0.6 mm which is concentrically provided on the opening peripheral edge of the die insertion hole. The second punch with a flat tip surface or the second punch with a frustoconical recess on the tip surface is used to finish-form into a disk shape or a thin shape. Since a vertical straight portion is always formed on the outer peripheral surface of the head of the rivet-type electric contact that can be absorbed, variation in head diameter is greatly reduced. In addition, the die is made of carbide, and the center hole is suppressed to 0.01 mm or less because the insertion hole of the columnar contact material and the concave part of the opening peripheral edge are created by electrical discharge machining. Center shift between the head and leg of the electrical contact is greatly suppressed.

The reason why the depth of the concave portion of the die is 0.2 to 0.6 mm is that the variation of the volume of the cylindrical contact material cannot be absorbed if it is less than 0.2 mm, and the finish molding is performed if it exceeds 0.6 mm. This is because the straight portion perpendicular to the outer peripheral surface of the rivet head is not formed, and the variation in head diameter cannot be reduced.

[0011]

EXAMPLE A method of manufacturing a rivet-type electrical contact according to the present invention will be described with reference to the drawings. As shown in FIG. 1A, a peripheral edge of a contact insertion hole 2 having a diameter of 1.45 mm of a die 1 made of cemented carbide. A recess 21 with a depth of 0.4 mm and a diameter of 3.0 mm is concentrically formed by electrical discharge machining, and the contact insertion hole 2 of this die 1
A cylindrical contact material 3 made of AgcdO 12 wt% having a diameter of 1.4 mm and a length of 2.48 mm is inserted to have a length of 0.6 mm, and then, as shown in FIG. A truncated cone-shaped head 5'having a diameter of 2.37 mm and a height of 1.06 mm is preformed, and then a second punch 22 having a flat tip surface as shown in FIG. 1c has a diameter of 3.0 mm and a thickness of 0.4. A mm-shaped disk-shaped head 23 was finish-molded to obtain a rivet-type electrical contact 24.

Next, another embodiment will be described with reference to the drawings.
As shown in Fig. 2a, the diameter of the die 1 made of carbide is 1.45.
mm of contact insertion hole 2 has a depth of 0.4 mm and a diameter of 3.0 mm.
A recess 21 of mm is formed concentrically by electric discharge machining, and the contact insertion hole 2 of the die 1 has a diameter of 1.4 mm and a length of 2.41 mm of AgcdO.
Insert a cylindrical contact material 3 consisting of 12 wt% to a length of 0.6 mm, and then use the first punch 4 as shown in FIG.
A pre-formed head-conical head 5 "having a diameter of 1.3 mm, an outer diameter of 2.16 mm, and a height of 1.76 mm, and then provided with a truncated cone-shaped recess 25 on the tip surface as shown in FIG. 2 Punch 26 with upper surface diameter 2.
A rivet-type electrical contact 28 was obtained by finish-molding a thin head 27 having an outer peripheral surface with a taper at a portion of 89 mm, outer diameter 3.0 mm, height 0.6 mm, and upper half 0.3 mm in height.

With respect to the rivet type electrical contacts 24 and 28 of the respective embodiments thus obtained, the center deviation of the head and the leg was examined by 30 pieces, respectively, and it was found to be within the range of 0.005 to 0.01 mm by the conventional method. The center deviation between the head and legs of the obtained rivet-type electrical contact was significantly less than the range of 0.03 to 0.05 mm. Further, the rivet type electrical contact 24 of each of the above embodiments,
When the variation of the head diameter (diameter 3.0 mm) was examined for 30 pieces of 28, the variation diameter of the head diameter (diameter 3.0 mm) of the rivet type electrical contact obtained by the conventional method in the range of diameter 3.01 to 3.02 mm. It was significantly less than the range of 3.01 to 3.08 mm.

[0014]

As described above, according to the method of manufacturing a rivet-type electrical contact of the present invention, in the manufacture of a rivet-type electrical contact, the variation in the head diameter can be greatly reduced, and the head and leg parts can be greatly reduced. Center shift can be greatly suppressed. Therefore, the rivet type electrical contact manufactured in this way can be fed by the parts feeder and the leg part can be correctly inserted into the contact mounting hole of the spring material, without interrupting the automatic crimping.
It can be done smoothly.

[Brief description of drawings]

1A, 1B and 1C are views showing steps of an embodiment of a method for manufacturing a rivet type electrical contact of the present invention.

2A, 2B and 2C are views showing steps of another embodiment of the method for producing a rivet type electrical contact according to the present invention.

3A, 3B, 3C and 3D are diagrams showing steps of a conventional method for manufacturing a rivet-type electrical contact.

4A and 4B are diagrams showing steps of another example of a conventional method for manufacturing a rivet-type electrical contact.

5 is a diagram showing a center shift between the second punch and the die in FIG. 3c.

FIG. 6 is a diagram showing a center shift between a head and legs of a rivet-type electrical contact made by the second punch and die of FIG.

7 is a diagram showing a case where a material volume is small when the head is molded by the second punch in FIG. 3c.

FIG. 8 is a diagram showing a case where a material volume is large when the head is formed by the second punch in FIG. 3C.

9 is a diagram showing a state in which burrs are generated on the peripheral edge of the upper surface of the head of the rivet-type electrical contact obtained by the manufacturing method shown in FIGS.

10 is a diagram showing a state in which a foil-like flutter remains even after the head of the rivet-type electrical contact of FIG. 9 is polished.

FIG. 11 is a schematic perspective view of a method for automatically crimping a contact material into a contact mounting hole of a spring material of a rivet-type electrical contact.

[Explanation of symbols]

 1 Die 2 Contact Insertion Hole 3 Cylindrical Contact Material 4 1st Punch 5'5 ″ Head with Conical Head 21 Recessed 22 Recessed Punch 23 Disc-shaped Head 24 Rivet Type Electrical Contact 25 Recessed 26 Second Punch 27 Thin head 28 Rivet type electrical contacts

Claims (1)

[Claims] 1. When manufacturing a rivet type electrical contact, a depth of 0.2 to 0.2 is formed at the peripheral edge of the insertion hole of a cylindrical contact material.
Insert the columnar contact material into the insertion hole of the die that is concentrically formed with a large-diameter recess of 0.6 mm, and then preform a conical head with the first punch, and then finish A method for producing a rivet-type electrical contact, characterized in that the disk-shaped or thin-shaped head is finish-molded by a flat second punch or a second punch having a truncated cone-shaped recess on the tip surface.