JPS6122841B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides a variable resistor that slides on a resistive film and a conductive film formed on an insulating substrate to change the resistance value between terminals that are electrically connected to the resistive film and the conductive film, respectively. Regarding a slider for a resistor.

Conventionally, as shown in FIG. 1, for example, this type of variable resistor has a circular arc shape surrounding a conductive film 2 formed at the center of the upper surface of a disk-shaped substrate 1 made of alumina porcelain. A rotor 5 made of an insulating resin is rotatably attached to the upper surface of the substrate 1 by means of a metal cover 4 via an O-ring 6, and a recess provided in the lower surface of the rotor 5 is formed. 7 accommodates a slider 8, and as the rotor 5 rotates, the slider 8 slides over the conductive film 2 of the substrate 1 and the cermet resistance element 3, thereby forming a terminal 9 that is electrically connected to the conductive film 2.
A variable resistor is known in which the resistance value between the terminals 12 and 13, which are electrically connected to both ends of the cermet resistance element 3 through electrode films 10 and 11, respectively, is changed. In the resistor, the following slider 8 is used.

That is, the slider 8, as shown in FIG.
A large number of elastic metal wires 21, 21, . . . are arranged densely, and a rectangular connection plate 22 made of metal with good electrical conductivity is placed thereon, and these connection plates 22 and the elastic metal wires 21, 21, . After spot welding the elastic metal wires 21, 21, ... and cutting the elastic metal wires 21, 21, ... at the dotted line positions, the tips of the elastic metal wires 21, 21, ... are shaped into semicircles, as shown in FIGS. The elastic metal wires 21, 21, . . . are bent to form a substantially V-shape between the contact portion 23 and the connection plate 22, and 21,
Due to the spring force of 21,..., the contact portion 23 is moved to the first position.
The conductive film 2 and the cermet resistance element 3 of the variable resistor shown in the figure are brought into pressure contact.

If the slider 8 has the above-described structure, the contact portion 23 is formed by a large number of elastic metal wires 21, 21, . . . Although the contact resistance with the connecting plate 23 can be reduced, it is difficult to spot-weld the connecting plate 21 by closely arranging a large number of elastic metal wires 22, 22, .
When the contact portion 23 slides on the conductive film 2 or the cermet resistance element 3, the width of the elastic metal wires 22, 22, ... tends to be larger than the width when the elastic metal wires 22, 22,... 21,
There was a drawback that part of 21,... sometimes meandered.

On the other hand, in order to eliminate the above drawbacks, Fig. 2a
and the outermost elastic metal wire 2 of the slider 8 of b.
As shown in FIG. 4, ribbon members 24, 24 having a width larger than the diameter of these elastic metal wires 21, 21 are spot welded to the connection plate 21. The ribbon members 24, 24 and the elastic metal wire 2 relative to the plate 22
1, 21, ... have different contact areas, and the elastic metal wires 21, 21, ..., which have smaller contact areas, are welded before the ribbon members 24, 24, resulting in a spot between the ribbon members 24, 24 and the connecting plate 22. In addition to the disadvantage that welding tends to be incomplete, the above-mentioned disadvantages of and still remain unsolved.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional slider for a variable resistor. The pair of legs lifted from the welding area is lifted by extending them in parallel and bending their bases to lift the legs, and by arranging elastic metal wires between these legs and welding them to the welding area. It is an object of the present invention to provide a slider for a variable resistor that can be easily welded to a welding part in a state where a large number of elastic metal wires are arranged.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, as shown in FIG.
A pair of legs 3 having a constant width along a and 31b
The legs 32a and 32b are formed by extending the legs 2a and 32b in parallel, and the bent parts 33a and 33b are formed by bending the bases of the legs 32a and 32b twice in opposite directions. Frame 3 lifted from the welded part 31
Use 4.

Between the pair of legs 32a and 32b lifted from the welding part 31 as described above, there are a large number of elastic metal wires 35 made of an elastic material such as phosphor bronze and plated with a noble metal such as gold plating on the outside. ,3
5,... are arranged, and these elastic metal wires 35,
35, . . . and the welded portion 31 of the frame 34 are spot welded.

The legs 32a, 32b of the frame 34 have the same thickness and lifting height as the elastic metal wires 35, 35, . . . , respectively.
2a, 32b and the leg portions 32a, 32b are the fifth
As shown in Figure b, it has a flat plate shape.

The tips of the elastic metal wires 35, 35, . . . and the legs 32a, 32b of the frame 34 are connected to the third
Similar to the slider 8 in FIG.
35,... are curved into a substantially V shape, and the sixth
The sliders for variable resistors are as shown in Figures a and b, respectively.

If the variable resistor slider has the above structure, the welded portion 31 has elastic metal wires 35, 35,
Since only... is welded, difficulties in spot welding such as the slider 8 in FIG. 31 is the leg portion 32a, 3
If it protrudes to both sides of 2b, the problem will disappear.

The slider for a variable resistor as described above is shown in Fig. 7a.
They can be easily manufactured as shown in f.

First, as shown in FIG. 7a, pilot holes 42 are formed in a strip-shaped metal plate 41 made of a material with good elasticity and electrical conductivity. In Figure 5a
Drilling of a rectangular square hole 45 and long holes 46, 46 so as to leave a welded part equivalent part 43 and leg part equivalent parts 44, 44 corresponding to the welded part 31 and leg parts 32, 32 of b, respectively. I do.

Next, extrusion processing is performed to extrude the leg portions 44, 44 above the metal plate 41, as shown in FIG. 7c.

Between the leg portions 44, 44 extruded above the metal plate 41 by the above extrusion process, as shown in FIG.
As shown in FIG. 3, after arranging the elastic metal wires 35, 35, . . . and spot-welding the elastic metal wires 35, 35, . ...Cut at the position indicated by the dotted line.

The cut ends of the elastic metal wires 35, 35, . . . and leg portions 44, 44 are processed to form contact portions 36 (see FIG.
4, 44 and the elastic metal wires 35, 35, . . . (see FIG. 7f), a slider for a variable resistor as shown in FIGS. 6a and 6b can be obtained.

If the above is done, the elastic metal wires 35, 3
5, . . . are positioned by a pair of leg portions 44, 44 pushed upward from the metal plate 41, and the welded portions 31 of these elastic metal wires 35, 35, .
Positioning can also be done extremely easily.

In the above embodiment, a rib 50 is provided on the welded portion 31 of the frame 34 by projection processing, as shown in FIG.
The contact area between the metal wires 35, 35, . . . and the elastic metal wires 35, 35, .

Further, the formation of the ribs 50 may be performed after the pilot hole machining shown in FIG. 7a, and in this case, two or more ribs 50 may be formed.

As is clear from the detailed description above, the present invention is characterized in that elastic metal wires are arranged between a pair of legs lifted from a welding part and these elastic metal wires are welded to the welding part. , a large number of elastic metal wires are positioned between a pair of legs lifted from the welding part, and the welding position of the elastic metal wires can be easily and reliably performed. will be welded, and the elastic metal wire will be welded uniformly to the weld.

Furthermore, since a frame is used in which the pair of legs extend integrally from the welded part, the welded part does not protrude to both sides of the legs, and the dimensional accuracy of the finished product is improved.

Furthermore, if a rib is provided at the welded part, the elastic metal wire and the rib will be in point contact,
Welding of both can be made more reliable.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional perspective view showing an example of a variable resistor, FIG. 2 is an explanatory diagram of a conventional method for manufacturing a slider for a variable resistor, and FIGS. A plan view and a front view showing an example of the mover,
FIG. 4 is a plan view of a conventional variable resistor slider using a ribbon member, FIGS. 5 a and 5 b are a plan view and a front view of a frame used in the variable resistor slider according to the present invention, 6a and b are respectively a plan view and a front view of a slider for a variable resistor according to the present invention, and FIGS. 7a to 7f are respectively FIGS. 6a and b.
Explanatory diagram of the manufacturing method of a slider for a variable resistor, No. 8
The figure is a plan view of a frame in which ribs are provided at welded parts. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Conductive film, 3... Cermet resistance element, 4... Cover, 5... Rotor, 8...
Slider, 9, 12, 13... terminal, 31... welding part, 32a, 32b... leg part, 33a, 33b...
...Bending portion, 34...Frame, 35...Elastic metal wire.

Claims (1)

[Claims] 1. In a variable resistor slider used for a variable resistor, a pair of legs each having a constant width are placed in parallel along opposite sides of a rectangular welded part made of an elastic and electrically conductive metal plate. At the same time, the base of the leg is bent and the leg is lifted from the welding part by a height approximately equal to the diameter of the elastic metal wire to be welded, and the elastic metal wire is placed between these legs. A slider for a variable resistor, characterized in that the above is arranged and welded to the welded portion.