JPH0410643Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a variable resistor having a slider made of conductive rubber.

(Prior Art) As shown in FIG. 1, a conventional variable resistor uses a conductive rubber slider inserted into a slider mounting hole 3 provided in a slider mounting portion 2 of an operating shaft member 1. There is a structure in which a slider 4 is attached and the slider 4 is pressed into contact with a resistor 6 and a current collector 7 on a substrate 5.
Since the conductive rubber slider itself has elasticity, the convex contact portions 8, 8 are connected to the resistor 6 and the current collector 7.
There is an advantage that there is no need to provide a spring member separate from the slider for urging the slider to press the slider into contact with the slider.

(Problem to be solved by the invention) In order to obtain stable characteristics, it is necessary to press the convex contact portions 8, 8 with a relatively large pressing force. It is necessary to increase the size (reduce the hardness of the slider 4). However, when the elasticity of the slider 4 is increased, the deformation rate of the slider 4 increases accordingly, and when the slider 4 is in pressure contact with the resistor 6 and the current collector 7, the slider 4, double-convex contact portion 8,
The bridge portion 4a between the two portions 8 may bulge toward the insulating substrate 5, and this bulge portion 9 may come into contact with the resistor 6 and the current collector 7, causing a short circuit or a spark. In addition, when such a bulge 9 comes into contact with the insulating substrate 5, sliding resistance becomes large and the operation shaft member 1 holding the slider 4 cannot be rotated smoothly.

(Purpose of the invention) The purpose of the invention is to prevent parts other than the convex contact portions of the slider from coming into contact with the resistor and current collector even if the elasticity of the conductive rubber slider is increased. It is an object of the present invention to provide a variable resistor which can perform the rotation operation of an operating shaft member smoothly.

(Means for Solving the Problems) The present invention consists of an insulating substrate on which a resistor and a current collector are formed, a cover attached to the insulating substrate, and an operating shaft member rotatably attached to the cover. and a slider mounting hole provided in the operating shaft member, and a convex contact portion at both ends that is fitted into and attached to the slider mounting hole and contacts the resistor and the current collector. The present invention is directed to a variable resistor comprising a conductive rubber slider having a structure in which contact portions are integrally connected by a bridge portion, and the slider is pressed into contact with a resistor and a current collector.

In the present invention, a concave part is provided at the bottom of the slider mounting hole to release the bulge of the slider's flesh that occurs when the slider is pressed into contact with the resistor and the current collector. The biconvex contact portion is provided so as to face the connecting portion connecting the two contact mounting portions to which the biconvex contact portion is attached, and not to face the two contact mounting portions. Further, there is substantially no space formed between the outer circumferential surface of the contact mounting portion and the wall surface of the slider mounting hole to allow the bulge of the slider's flesh to escape.

(Operation of the invention) In order to increase the pressing force of the convex contact portion, the elasticity of the conductive rubber slider is increased, and the convex contact portion of the slider is connected to the resistor of the insulating substrate and the current collector. A part of the flesh of the slider that bulges out when pressed into contact with the slider escapes into the recess provided in the slider mounting hole. Therefore, a bulge that comes into contact with the resistor and the current collector is not formed as in the conventional case. In addition, the concave portion is arranged in the slider mounting hole so that it faces the connecting portion connecting the two contact mounting portions to which the double convex contact portion of the bridge portion of the slider is attached, and does not face the two contact mounting portions. A concave portion is formed by providing a recess at the bottom of the contact mounting portion and substantially not forming a space between the outer circumferential surface of the contact mounting portion and the wall surface of the slider mounting hole to allow the bulge of the slider flesh to escape. Since the contact mounting part of the bridge part does not deform significantly even when the contact mounting part is changed, the shape of the convex contact part provided on the contact mounting part and the mounting angle of the convex contact part with respect to the resistor and current collector part also change greatly. Stable characteristics can be obtained without any problems.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an embodiment of the present invention, in which reference numeral 11 denotes an insulating substrate made of ceramic or synthetic resin. A resistor 12 and a current collector 13 are formed on the surface of this insulating substrate 11 by printing or the like. A cover 14 is attached to the insulating substrate 11.
is attached, and the cover 14 covers the surface side of the substrate 11 on which the resistor 12 and the current collector 13 are disposed. A bearing member insertion hole 15 is formed in the cover 14, and a bearing member 16 is mounted in this hole 15. The bearing member 16 is formed into a substantially cylindrical shape, and the shaft portion 17a of the operating shaft member 17 is supported in the hole portion 16a. The operating shaft member 17 has a slider mounting portion 17b formed integrally with the shaft portion 17a and disposed within the cover 14, and the slider mounting portion 17b has an opening toward the insulating substrate 11. A slider mounting hole 18 is formed. In this embodiment, the bottom 18a of the slider mounting hole 18 is
A recess 19 is formed in the bulge 20a of the flesh that is generated when the conductive rubber slider 20 fitted in the slider mounting hole 18 comes into pressure contact with the resistor 12 and the current collector 13. It is designed to escape into this recess 19. The slider 20 consists of convex contact portions 21, 21 located at both ends and in contact with the resistor 12 and current collector 13, and a bridge portion 22 that integrally connects both convex contact portions 21, 21, It is integrally molded from conductive rubber. The bridge portion 22 is a contact attachment portion 22a, 22a to which the convex contact portion 21 is attached, and a connecting portion 22 that connects the two contact attachment portions 22a, 22a.
It consists of b. As shown in the figure, substantially no space is formed between the outer peripheral surfaces of the contact mounting portions 22a, 22a of the bridge portion 22 and the wall surface of the slider mounting hole 18. In other words, bridge part 22
is fitted into the slider mounting hole 18 with virtually no gap. Further, as shown in the figure, the recessed portion 19 is formed so as not to face the contact mounting portions 22a, 22a of the bridge portion 22. Note that 23 is an intermediate terminal attached to the substrate 11 and connected to the current collector 13.

In the variable resistor configured as above,
As shown in FIG. 3, the convex contact portion 2 of the slider 20
1 and 21 are the resistor 12 of the insulating substrate 11 and the current collector 1
3, the slider 20 is crushed and a part of its flesh bulges out, and the bulge 20a is brought into contact with the recess 19.
contained within. In this embodiment, the bridge portion 22
Since the outer peripheral surfaces of the contact mounting portions 22a, 22a are firmly supported by the wall surface of the slider mounting hole 18, the degree of deformation of the contact mounting portions 22a, 22a is small. Therefore, deformation of the convex contact portions 21 and 21 and change in the mounting angle with respect to the resistor 12 and the current collector 13 can be suppressed.

According to this embodiment, the parts other than the convex contact portions of the slider do not come into contact with the resistor and the current collector as in the conventional case, and the slider 20 does not come into contact with the resistor and the current collector. Since only the convex contact portions 21, 21 of the two contacts are in contact with each other, short circuits and sparks can be prevented, and sliding can be performed smoothly.

(Effects of the Invention) As described above, according to the present invention, even if the elasticity of the conductive rubber slider is increased in order to increase the pressing force of the convex contact portion, the convex contact portion of the slider When the slider is pressed into contact with the resistor of the insulated substrate and the current collector, a part of the slider flesh that bulges out escapes into the recess made in the slider mounting hole, so the resistance There are advantages in that no bulging portion is formed that would come into contact with the body and the current collector, thereby preventing short circuits and sparks, and allowing smooth rotation of the operating shaft member. In particular, according to the present invention, the recess is
Provided at the bottom of the slider mounting hole so as to face the connecting part connecting the two contact mounting parts to which the double convex contact part of the bridge part of the slider is attached, and not to face the two contact mounting parts. Moreover, since there is virtually no space formed between the outer circumferential surface of the contact mounting part and the wall surface of the slider mounting hole for the bulging part of the slider's flesh to escape, even if a recess is formed, The contact mounting part of the bridge part does not deform significantly, and the shape of the convex contact part provided on the contact mounting part and the mounting angle of the convex contact part with respect to the resistor and current collector part do not change significantly, making it stable. It has the advantage of being able to obtain certain characteristics.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a conventional variable resistor, Fig. 2 is an exploded explanatory view of the variable resistor according to the first embodiment of the present invention, and Fig. 3 is a longitudinal cross-sectional view of the first embodiment of the present invention. be. 11...Insulating substrate, 12...Resistor, 13...
Current collector, 14...Cover, 17...Operation shaft part, 1
8... Slider mounting hole, 18a... Bottom of slider mounting hole, 19... Concave portion, 20... Conductive rubber slider, 21... Convex contact portion, 22... Bridge portion,
22a...Contact mounting part.

Claims (1)

[Claims for Utility Model Registration] An insulating substrate on which a resistor and a current collector are formed, a cover attached to the insulating substrate, and an operating shaft member rotatably attached to the cover,
A slider mounting hole provided in the operating shaft member, and a convex contact portion fitted in and attached to the slider mounting hole and in contact with the resistor and the current collector at both ends. A variable resistor comprising a conductive rubber slider having a structure in which convex contact portions are integrally connected by a bridge portion, and the slider is in pressure contact with the resistor and the current collector, wherein the sliding A concave portion for escaping the bulge of the flesh of the slider that occurs when the slider is brought into pressure contact with the resistor and the current collector is provided at the bottom of the slider mounting hole with the two convex portions of the bridge portion. facing the connecting portion connecting the two contact mounting portions to which the shaped contact portions are attached;
The contact mounting portion is provided so as not to face the two contact mounting portions, and there is substantially a space between the outer circumferential surface of the contact mounting portion and the wall surface of the slider mounting hole for allowing the bulging portion of the slider flesh to escape. A variable resistor characterized by not being formed into a.