JPH0432202A - Variable resistor - Google Patents

Abstract

PURPOSE:To chip less resistor pattern by elastically applying an elastic body to the inner wall of a case and fixing a rotation shaft to the case rotatably. CONSTITUTION:The rotation shaft 5 of a rotation shaft member 2 is passed through an insertion hole 9 from the inside of a case 3 and fixed thereto rotatably. In this time, a flange 6 is housed in a housing recession 8 and a spring 12 is elastically transformed and elastically applied to the peripheral wall 8a of the housing recession 8. The elastic applying force generates the rotation torque of the rotation shaft member 2 and an insulating substrate is attached to the case 3 with bond with the open end of the case 3 closed. When the insulating substrate 4 is attached to the case 3, a resistor pattern 10 on the insulating substrate 4 is applied by pressing to slider 7 at the lower end of the flange 6. However, the elastic applying force to apply the slider 7 to the resistor by pressing does not need to be greater than required for connection because the rotation shaft member 2 is provided with sufficient rotation torque by the spring 12, therefore, less resistor is chipped by sliding the slider.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a variable resistor in which a slider rotates and slides on a resistor to vary the resistance value.

<Prior Art> Conventionally, as a variable resistor for high voltage, one shown in FIG. 4 has been known. This variable resistor 20 is connected to the rotating shaft portion 2
, a case 3, and an insulating substrate 4. The rotating shaft portion 2 includes a rotating shaft 5 and a flange 6 provided at the end of the rotating shaft 5, and the lower end of the flange 6 is provided with a slider 7 extending downward. This slider 7 is made of an elastic body such as a leaf spring. The case 3 is open at the lower end. Further, a rotary shaft member storage recess 8 is formed on the upper end side of the case 3, and an insertion hole 9 is formed in the center of the storage recess 8, which communicates with the inside and outside of the case. The insulating substrate 4 has a resistor pattern 10 at a predetermined location on its surface.
is formed by printing, etc.

The rotating shaft portion 2 is rotatably attached to the case 3. That is, the rotating shaft 5 is inserted into the insertion hole 9 with the flange 6 housed in the housing recess 8 . The insulating substrate 4 is
It is attached to the open end of the case 3 with an adhesive or the like with the surface facing inside the case 3, and the resistance pattern IO is in pressure contact with the slider 7.

This variable resistor 20 rotates the rotary shaft portion 2 from outside the case 3 to move the slider 7 into the resistance pattern 10.
By sliding it on the top, you can change the resistance value. Note that the reference numeral 11 indicates grease provided in the insertion hole 9 as necessary.

<Problems to be Solved by the Invention> By the way, in the variable resistor 20, it is necessary to obtain a predetermined rotational torque in the rotating shaft portion 2. Therefore, conventionally, the rotational torque is obtained by the elastic repulsive force caused by the spring pressure when the slider 7 is pressed against the insulating substrate 4. Therefore, when it is necessary to obtain a large rotational torque, the slider 7 is pressed against the surface of the resistance pattern 10 more than necessary, and if the slider 7 repeatedly slides, the resistance Pattern 10 is
The surface was scraped off, causing electrical noise.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a variable resistor that can reduce scraping of the resistance pattern, which causes electrical noise.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a variable resistor in which a slider rotates and slides on a resistor, comprising a case and a rotating shaft, The case houses the resistor, and the rotating shaft includes the slider and an elastic body that generates an elastic force in the radial direction of the slider. A variable resistor was constructed by rotatably attaching the rotary shaft portion to the case while making elastic contact with the inner wall.

<Operation> According to the above configuration, the rotating shaft portion is rotatably attached to the case with the elastic body elastically abutting against the inner wall of the case. Therefore, the rotational torque of the rotating shaft is also obtained by the friction in the radial direction between the elastic body and the inner wall of the case, and the slider does not have to serve to impart more rotational torque than necessary. No more pressure is applied to the top than necessary.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 1 is a longitudinal cross-sectional view of a high-voltage variable resistor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■--■.

The structure of this variable resistor 1 is basically the same as that of the conventional example, and the same or similar members and components are given the same reference numerals and detailed explanations will be omitted.

The characteristic structure of this embodiment is that a spring member 1 is attached to the rotating shaft portion 2.
2 (elastic body). The rotating shaft portion 2 is formed of an integrally molded resin such as modified PP0 (polyphenylene oxide) or PBT (polybutylene terephthalate). Therefore, the spring member 12 made of the same resin as the rotating shaft portion 2 is attached to the rotating shaft portion 2 by integral molding. In the case of this embodiment, the spring member 12 is formed at a predetermined location on the circumferential surface of the flange 6, and its free end side 12a is attached to the flange 6.
It extends radially outward (in the radial direction of the rotating shaft). Further, the distance between the tip of the free end 12a of the spring member and the axis of the rotating shaft portion 2 is set to be slightly larger than the inner circumferential radius of the storage recess 8 of the case 3.

In the figure, reference numeral 13 is one protrusion provided on the flange 6 for limiting the rotation range. The fixed end side 12b of the spring member 12 also serves as the other projection for limiting the rotation range.

The rotating shaft portion 2 is rotatably attached to the case 3 by inserting the rotating shaft 5 into the insertion hole 9 from inside the case 3, as in the conventional example. At this time, the flange 6 is stored in the storage recess 8, and at this time, the spring member 12 is elastically deformed and comes into elastic contact with the peripheral wall 8a of the storage recess 8. This elastic contact force forms the rotational torque of the rotating shaft portion 2. Then, the insulating substrate 4 is attached to the case 3 with an adhesive or the like so as to close the open end of the case 3. When the insulating substrate 4 is attached to the case 3, the resistance pattern IO on the insulating substrate 4 comes into pressure contact with the slider 7 provided at the lower end of the flange 6, as in the conventional example. However, the rotational shaft portion 2 is configured such that sufficient rotational torque can be obtained by the spring member 12.

Therefore, the slider 7 does not need to be pressed with an unnecessarily large pressure contact force, and the spring pressure of the slider 7 is set with this point in mind.

In the above embodiment, the spring member 12 has a structure in which it is supported by the flange 6 in a cantilever manner, but as shown in FIG. good.

In addition, in the above example, the experiment was carried out in a high voltage variable resistor, but it is not limited to this.
Any type of variable resistor in which a slider rotates and slides on a resistor can be used.

Furthermore, in the above embodiment, the elastic body is
Although the spring member 12 is an integrally molded product made of the same resin as the spring member 12, the elastic body may be made of a separate member such as a leaf spring and attached to the rotating shaft. An elastic body may be formed on the circumferential surface of the rotating shaft 5.

<Effects of the Invention> As described below, according to the present invention, rotational torque can be obtained by the elastic body provided on the rotating shaft, and the slider does not rotate more than necessary on the rotating shaft. There is no longer a need to provide torque. Therefore, the slider only needs to be pressed onto the resistor with an elastic contact force necessary for connection, and the scraping of the resistor due to sliding of the slider is reduced. Therefore, it has become possible to apply a large rotational torque to the rotating shaft portion without causing the inconvenience of generating electrical noise.

[Brief explanation of drawings]

1 and 2 relate to one embodiment of the present invention, in which FIG. 1 is a longitudinal cross-sectional view, and FIG. 2 is a cross-sectional view taken along the line ■--■ in FIG. FIG. 3 is a longitudinal sectional view of another embodiment. FIG. 4 is a longitudinal sectional view of a conventional example. 1... Variable resistor 2... Rotating shaft portion 3... Case 7... Slider 8a... Storage recess peripheral wall (case inner wall) IO/Resistance pattern 12... Spring member (elastic body)

Claims (1)

[Claims] (1) A variable resistor in which a slider (7) rotates and slides on a resistor (10), which includes a case (3) and a rotating shaft (
2), the case (3) houses the resistor (10), and the rotating shaft (2) includes the slider (7) and is elastic in the radial direction. It is equipped with an elastic body (12) that generates a force, and the elastic body (12) is brought into elastic contact with the inner wall (8a) of the case (3), and the rotating shaft part (2) is attached to the case (3). A variable resistor characterized by being rotatably mounted.