JP2997181B2 - Rotary variable resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary operation for adjusting a resistance value by changing a sliding contact position between a resistor and a slider piece by rotating an operating body with an adjusting jig such as a screwdriver. More particularly, the present invention relates to a chip-type rotary variable resistor surface-mounted on a printed circuit board.

[0002]

2. Description of the Related Art A small rotary variable resistor having a small external dimension has conventionally been provided with a stopper structure for regulating the rotation angle of an operating body as described in Japanese Utility Model Laid-Open No. 5-72105. The adopted one has been proposed.

FIG. 6 is a sectional view of a rotary variable resistor described in the above publication, and FIG. 7 is an exploded perspective view of the rotary variable resistor. Is a base 10 made of synthetic resin and an operating body 11 made of synthetic resin.
And a metal stop plate 12 and a metal intermediate terminal 13. A shaft hole 10 is provided at the center of the surface of the base 10.
A concave portion 10b having a is provided, and a resistance substrate 14 is mounted on the inner bottom surface of the concave portion 10b. Although not shown, a horseshoe-shaped resistor is formed on the resistor substrate 14 by printing, and a pair of terminals 1 connected to both ends of the resistor is formed.
5 (one not shown) protrudes below the base 10. On the other hand, an adjusting groove 11a engageable with an adjusting jig such as a screwdriver is integrally formed on the surface of the operating body 11, and a slider piece 16 is mounted on the back surface of the operating body 11. The slider piece 16 is in sliding contact with a resistor on the resistor board 14. The stop plate 12 is provided with a flange portion 12b having a stopper projection 12a and an eyelet portion 12c inserted into the shaft hole 10a.
Is fixed to the slider piece 16 by caulking. Further, the intermediate terminal 13 is electrically connected to the slider piece 16 via the stop plate 12 by being sandwiched between the back surface of the base 10 and the flange portion 12b of the stop plate 12. Base 1
It has a terminal portion 13a protruding downward from the bottom.

In the rotary variable resistor constructed as described above, when an operating jig 11 is rotated by inserting an adjusting jig such as a screwdriver into the adjusting groove 11a, a slider for the resistor on the resistor substrate 14 is rotated. Since the sliding position of the piece 16 changes, a change in the resistance value is detected via the intermediate terminal 13.
Further, since the stop plate 12 rotates integrally with the operation body 11,
At the position where the stopper protrusion 12a contacts the terminal portion 13a of the intermediate terminal 13, the rotation angle of the operating body 11 is regulated.

[0005]

In the above-mentioned conventional stopper structure, the stopper projection 12a of the stop plate 12 which rotates integrally with the operating body 11 is provided with the terminal portion 13a of the intermediate terminal 13 projecting below the base 10. , The rotation angle of the operating body 11 is regulated, so that it can be used for a relatively small rotary variable resistor.
However, in the case of a chip-shaped rotary variable resistor in which each terminal is surface-mounted on a solder land of a printed circuit board, each terminal cannot protrude below the base, and each terminal extends along the back surface of the base. Because of the necessity of disposition, it is impossible to adopt the above-mentioned conventional stopper structure, and a chip-type rotary variable resistor provided with a stopper structure is demanded.

The present invention has been made in view of such circumstances and demands of the prior art, and has as its object to provide a tip-shaped rotary variable resistor provided with a stopper structure for restricting a rotation angle of an operating body. Is to provide.

[0007]

In order to achieve the above object, the present invention provides a base having a horseshoe-shaped resistor formed on a surface thereof, and a base rotatably disposed on the base. And a metal operating body having a slider piece that slides on the slider, and by rotating the operating body with an adjusting jig, the sliding contact position between the resistor and the slider piece is adjusted. In the rotary variable resistor configured as described above, a tubular portion is formed on the operating body, and a projecting portion that protrudes outward is formed on a part of the tubular portion, thereby forming a resistor on the base. A concave portion into which the cylindrical portion is inserted is formed substantially at the center of the surface , and a stopper is formed in the concave portion, and the overhanging portion contacts the stopper so as to regulate the rotation angle of the operating body. It is characterized by having been constituted. Further, in the above configuration, the inside of the overhang portion is continuous with the adjustment groove that can be engaged with the adjustment jig. Further, in the above configuration,
The overhanging portion is formed so as to bulge outward by breaking both sides thereof, and the broken surface is brought into contact with the stopper.

[0008]

When the operating body is rotated by an adjusting jig such as a screwdriver, the sliding contact position between the slider piece provided on the operating body and the resistor formed on the surface of the base changes, and the resistance value is changed. Is adjusted. At this time, the cylindrical portion of the operating body rotates inside the concave portion of the base, but when the projecting portion protruding from the cylindrical portion contacts the stopper formed in the concave portion, the operating body is further rotated. And the rotation angle of the operation body is restricted.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 1 is a plan view of a chip-type rotary variable resistor according to an embodiment of the present invention, FIG. 2 is a side view of the variable resistor, FIG. 3 is a rear view of the variable resistor, and FIG. FIG. 5 is an exploded perspective view of the variable resistor, taken along a line AA of FIG.

As shown in FIGS. 1 to 5, a chip-shaped rotary variable resistor according to the present embodiment includes a base 1 made of synthetic resin,
A metal operating body 2 rotatably disposed on the base 1
It is composed of At the center of the surface of the base 1, a recess 1a having a substantially circular shape in a plan view is provided, and a pair of stoppers 1b slightly projecting inward are formed on the peripheral surface of the recess 1a. The outer side of the concave portion 1a is a flat portion 1c substantially in a horseshoe shape in plan view, and the portion other than the flat portion 1c is formed in a stepped shape. A pair of terminals 3 and one intermediate terminal 4 are provided on the back surface of the base 1, and these terminals 3 and the intermediate terminal 4 are attached to the base 1 by outsert molding described later. Each terminal 3 is bent in a U-shape, and the upper part thereof is exposed to the flat portion 1c. The upper part of each terminal 3 and the flat part 1c are in the same plane,
The resistor 5 is formed by printing over the entire area of the flat portion 1c including these terminals 3. The eyelet member 6 is connected to the intermediate terminal 4.
The eyelet member 6 is formed integrally with the recess 1a.
Located in the middle of.

The operating body 2 includes an annular upper surface plate 2a, a slider piece 7 folded from the outer edge of the upper surface plate 2a to the back surface, and a cylindrical member extending downward from the center of the upper surface plate 2a. Part 8
These are formed by pressing a single metal flat plate. A through hole 8 is formed in the bottom of the cylindrical portion 8.
The operating body 2 is rotatably supported on the base 1 by inserting the eyelet member 6 into the through hole 8a and caulking. 5 on top. Four adjusting grooves 8b each having a fractured surface on both sides are formed in the upper portion of the cylindrical portion 8, and overhanging portions 8c having the same fractured surfaces on both sides are formed from the upper portion to the lower portion of the cylindrical portion 8. The groove formed inside the overhang portion 8c is the adjusting groove 8b.
To one of That is, of the adjustment grooves 8b, three adjustment grooves 8b are connected to the inner peripheral edge of the upper surface plate 2a and the peripheral surface of the cylindrical portion 8, but the remaining adjustment grooves 8b are formed on the upper surface plate 2a. The inner peripheral edge is connected to the upper end of the overhang portion 8c. The adjusting grooves 8b are arranged in a cross shape at regular intervals of 90 degrees so that the adjusting jig 9 such as a screwdriver is engaged with the adjusting grooves 8b when the operating body 2 is rotated. Has become. The lower portion of the overhang 8c is located in the recess 1a of the base 1, and when the operating body 2 is rotated, the broken surface of the overhang 8c abuts the stopper 1b formed in the recess 1a. Thus, the rotation angle of the operation body 2 is restricted within a predetermined range.

The chip-shaped rotary variable resistor configured as described above can be obtained by soldering both terminals 3 and intermediate terminals 4 to solder lands on a printed circuit board (not shown).
It is surface-mounted on the printed circuit board. As a result, for example, when a predetermined voltage is applied between the two terminals 3 and an intermediate voltage is taken out from the intermediate terminal 4 connected to the operating body 2 via the eyelet member 6, when the slider piece 7 and the resistor 5 A change in the resistance value according to the sliding position can be output. When the resistance value is finely adjusted, when the tip of the adjustment jig 9 is engaged with the adjustment groove 8b and rotated, the operating body 2 rotates about the eyelet member 6, so that the slider piece is rotated. 7 slides on the resistor 5 to change the resistance value. At this time, the lower portion of the cylindrical portion 8 provided on the operating body 2 rotates in the concave portion 1a of the base 1, but the protruding portion 8c formed on the peripheral surface of the cylindrical portion 8 has a broken surface. When it comes into contact with one of the pair of stoppers 1b, the operating body 2
Cannot be rotated any further, and the rotation angle of the operating body 2 is restricted within a predetermined angle range.

As described above, in the above embodiment, the projecting portion 8c is formed so as to protrude from the cylindrical portion 8 of the operating body 2, and the projecting portion 8c is formed in the recess 1a of the base 1 in the stopper 1b.
, So that the base 1 and the operating body 2 are prevented from increasing in size in the radial direction, and a surface mounting type ultra-compact chip-shaped rotary variable resistor can have a stopper function. . Further, since the overhang portion 8c is connected to one of the adjustment grooves 8b, the groove formed inside the overhang portion 8c can be used as a part of the adjustment groove 8b, which is also effective for downsizing. . Also, since the broken surface of the overhang portion 8c is brought into contact with the stopper 1b, the overhang portion 8c is
This makes it hard to slip against b, and can increase the stopper strength. Further, the intermediate terminal 4 is outsert to the base 1 made of synthetic resin, and the cylindrical portion 8 of the operating body 2 is swaged to the eyelet member 6 integrally formed with the intermediate terminal 4, so that the number of parts is reduced and the cost is reduced. Down can be planned.

In the above embodiment, the case where each adjusting groove 8b is formed in a cross shape corresponding to a Phillips screwdriver has been described. However, the tip of the adjusting jig 9 using the shape of the adjusting groove 8b is used. It may be changed appropriately according to the shape. For example, two adjusting grooves 8b may be formed in a straight line so as to engage with a flathead screwdriver.

Further, in the above embodiment, the eyelet member 6 integrally formed with the intermediate terminal 4 is inserted into the through hole 8a of the cylindrical portion 8 and caulked so that the operating body 2 can be rotated on the base 1. Although the case of supporting is described, on the contrary, an eyelet may be formed at the lower end of the tubular portion 8 and this eyelet may be swaged in a through hole formed in the intermediate terminal 4.

[0016]

As described above, according to the present invention,
A protrusion is formed on the cylindrical part of the operating body so as to abut against a stopper formed in the recess of the base. It can be provided in a chip-shaped rotary variable resistor. Further, when the inside of the overhang portion is continuous with the adjustment groove, the groove formed inside the overhang portion can be used as a part of the adjustment groove, so that the operating body can be downsized and the processing thereof can be simplified. . Further, when the both sides of the overhanging portion are broken and this broken surface is brought into contact with the stopper, the overhanging portion is less likely to slip with respect to the stopper, so that the stopper strength can be increased.

[Brief description of the drawings]

FIG. 1 is a plan view of a chip-type rotary variable resistor according to an embodiment of the present invention.

FIG. 2 is a side view of the variable resistor.

FIG. 3 is a rear view of the variable resistor.

FIG. 4 is a sectional view taken along line AA of FIG.

FIG. 5 is an exploded perspective view of the variable resistor.

FIG. 6 is a sectional view of a conventional rotary variable resistor.

FIG. 7 is an exploded perspective view of the rotary variable resistor.

[Explanation of symbols]

 Reference Signs List 1 base 1a recess 1b stopper 1c flat part 2 operating body 2a top plate 3 terminal 4 intermediate terminal 5 resistor 6 eyelet member 7 slider piece 8 cylindrical part 8a through hole 8b adjusting groove 8c overhanging part 9 adjusting jig Ingredient

Claims (3)

(57) [Claims] An operating body made of a metal plate having a horseshoe-shaped resistor formed on the surface thereof and a slider piece rotatably disposed on the base and slidingly contacting the resistor. A rotary variable resistor, wherein the operating body is rotated by an adjusting jig to adjust a sliding contact position between the resistor and a slider piece; A tubular portion is formed on the operating body, and a protruding portion that protrudes outward is formed on a part of the tubular portion, and the tubular portion is inserted into substantially the center of the resistor forming surface of the base. And a stopper is formed in the recess, and a rotation angle of the operating body is regulated by the projecting portion contacting the stopper. Variable resistor. 2. The rotary variable resistor according to claim 1, wherein the inside of the overhang portion is continuous with an adjusting groove engageable with the adjusting jig. 3. The rotary variable resistor according to claim 1, wherein the overhang portion is formed so as to bulge outward by breaking both sides, and the broken surface is brought into contact with the stopper. .