JP2534306Y2 - 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 variable resistor, and more particularly to a small semi-fixed variable resistor having a small external dimension.

[0002]

2. Description of the Related Art FIG. 4 is an exploded perspective view showing a conventional semi-fixed variable resistor. The variable resistor shown in FIG. 4 is made of a synthetic resin material, and has a concave portion 1 at one end and the concave portion at the center. A molded body 3 provided with a shaft hole 2 communicating the other end with a resistor substrate 4 provided at the inner bottom of the concave portion 1 and a metal plate material. The molded body 3 is rotatably supported by the molded body 3. Stop plate 5,
A knob 6 is provided in the recess 1 and fixed to one end of the stop plate 5, and a slider (not shown) is provided on the bottom side of the knob 6 and slides on the resistance substrate 4. .

A terminal 4a and other terminals (not shown) are integrally provided at both ends of the above-described resistance substrate 4, respectively.
The above-mentioned stopper plate 5 has a cylindrical portion 5 a inserted into the shaft hole 2.
Having. An intermediate terminal 7 made of a metal plate is interposed between the flange 5b of the stop plate 5 and the bottom surface of the molded body 3, and the intermediate terminal 7 is electrically connected to the slider. The above-described knob 6 has an adjustment hole 8 into which an adjustment tool such as a screwdriver is inserted.

In such a variable resistor, a predetermined voltage is applied between the end 4a and the other end, and an intermediate voltage is applied from the intermediate terminal 7 via a slider sliding on the resistance substrate 4. To take out. Then, by inserting an adjustment tool such as a screwdriver into the adjustment hole 8 of the knob 8 and rotating the knob 8, the sliding position of the slider with respect to the resistance substrate 4 is moved, thereby The value of the intermediate voltage extracted from the intermediate terminal 7 via the terminal is adjusted. At this time, since the knob 6 is fixed to one end of the stop plate 5 and the stop plate 5 is rotatably supported by the molded body 3, the knob 6 and the stop plate 5 rotate integrally.

[0005]

By the way, in the above-mentioned conventional variable resistor, considering the dimensional error and the like occurring in each member, the gap between the shaft hole 2 of the molded body 3 and the cylindrical portion 5a of the stop plate 5 is taken into consideration. A gap is required. However, when such a gap exists, the stopper plate 5 moves in the radial direction with respect to the molded body 3, that is, the slider provided on the knob 6 easily swings in the radial direction with respect to the resistance substrate 4. As a result, there is a concern that the resistance value taken out through the slider may be out of order, and the accuracy of the resistance value may be inferior. In particular, in the case of a small variable resistor, the above-mentioned problem is remarkable.

When the gap between the shaft hole 2 of the molded body 3 and the cylindrical portion 5a of the stop plate 5 is to be set to be zero, the shaft hole 2
And the rotational resistance between the cylindrical portion 5a becomes excessive,
Rotation of the knob 8 becomes extremely difficult, which impairs operability. Therefore, a gap having a predetermined size is required between the shaft hole 2 and the cylindrical portion 5a.

The present invention has been made in view of such a situation in the prior art, and its object is to allow the knob to rotate smoothly and to prevent the knob from moving in the radial direction. An object of the present invention is to provide a variable resistor.

[0008]

In order to achieve this object, the present invention provides a molded article made of synthetic resin having a concave portion at one end and a shaft hole communicating the concave portion with the other end. A resistance board provided at the inner bottom portion, a metal stop plate having a cylindrical portion inserted into the shaft hole and rotatably supported by the molded body, and one end of the stop plate provided at the recess And a slider provided on the knob and sliding on the resistance board, the variable resistor comprising:
A plurality of protrusions extending in the axial direction and abutting on the outer peripheral surface of the cylindrical portion are provided on the inner peripheral surface of the shaft hole.

[0009]

Since the present invention is configured as described above, the plurality of projections provided in the shaft hole of the molded body abut on the outer peripheral surface of the cylindrical portion of the stop plate to restrict the stop plate from moving in the radial direction. Thus, it is possible to prevent the knob from moving in the radial direction. And since only the protrusion extending in the axial direction abuts on the outer peripheral surface of the cylindrical portion as described above, the contact area between the two is small and the rotational resistance does not become excessive, whereby the knob can be smoothly rotated. Can be.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the variable resistor according to the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing an embodiment of the variable resistor according to the present invention, FIG. 2 is a sectional view of the variable resistor shown in FIG.
FIG. 3 is a plan view for explaining a main configuration of a molded body provided in the variable resistor in FIG. 1 to 3, the same components as those shown in FIG. 4 described above are denoted by the same reference numerals. That is, 4 is a resistance substrate, 5 is a stop plate, 5a is a cylindrical portion, 5b is a flange portion, 6 is a knob, 7 is an intermediate terminal, and 8 is an adjustment hole.

The variable resistor according to the present embodiment shown in FIG. 1 includes a molded body 10 made of a synthetic resin and a knob 6, similarly to the conventional variable resistor shown in FIG. As shown in FIG. 2, the molded body 10 has a concave portion 11 in which a resistance substrate 4 is provided on an inner bottom portion, and a shaft hole 12 communicating with the concave portion 11, and the knob 6 is provided on the bottom surface side. It has a slider 13 that slides on the resistance substrate 4. Further, in the variable resistor of this embodiment, as shown in FIG. 3, three projections extending in the axial direction of the shaft hole 12 and abutting on the outer peripheral surface of the cylindrical portion 5a of the stop plate 5, respectively. 14, 1
5 and 16 are provided at equal intervals.

In this embodiment, the cylindrical portion 5 of the stop plate 5
When a is inserted into the shaft hole 12 of the molded body 10, the cylindrical portion 5 a of the stop plate 5 comes into contact with the projections 14 to 16 provided in the shaft hole 12, and the stop plate 5 moves in the radial direction. Be regulated.

In the embodiment configured as described above, the protrusion 14
Since the movement of the stop plate 5 in the radial direction is restricted by the abutment of Nos. To 16, the movement of the knob 6 fixed to one end of the stop plate 5 in the radial direction can be prevented. Further, since only the projections 14 to 16 abut on the outer peripheral surface of the cylindrical portion 5a of the stop plate 5 as described above, the contact area between the shaft hole 12 and the cylindrical portion 5a is reduced, and the knob 6 can be smoothly rotated. Can be.

[0014]

[Effects of the Invention] Since the present invention is constructed as described above, it is possible to prevent the knob from moving in the radial direction, and therefore it is possible to improve the accuracy of the resistance value. Further, since the knob can be smoothly rotated, the operability of the knob is not impaired.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a variable resistor according to the present invention.

FIG. 2 is a cross-sectional view of the variable resistor of FIG.

FIG. 3 is a plan view illustrating a configuration of a main part of a molded body provided in the variable resistor in FIG. 1;

FIG. 4 is an exploded perspective view showing a conventional variable resistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 Resistance board 5 Stop plate 5a Cylindrical part 6 Knob 10 Molded body 11 Concave part 12 Shaft hole 13 Slider 14-16 Projection

Claims (1)

(57) [Scope of request for utility model registration] 1. A molded article made of synthetic resin having a concave portion at one end and having a shaft hole communicating the concave portion with the other end, a resistive substrate provided at an inner bottom portion of the concave portion, and inserted through the shaft hole. A metal stopper plate having a cylindrical portion to be rotatably supported by the molded body, a knob provided in the recess and fixed to one end of the stopper plate, and the resistor substrate provided on the knob A variable resistor provided with a slider that slides upward, wherein an inner peripheral surface of the shaft hole is provided with a plurality of protrusions extending in an axial direction and abutting on an outer peripheral surface of the cylindrical portion. Variable resistor.