JPS625324B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable resistor, and particularly to improvements in a multi-rotation variable resistor such as a trimmer type potentiometer.

Conventional variable resistors, especially trimmer type potentiometers, generally consist of a housing and a base, a resistor formed on the surface of a flat substrate such as ceramic, and an elastic resistor fixed to the bottom of a rotor on a current collecting electrode body. In most cases, the resistance value was adjusted by pressing a slider having a 100 mm diameter from the top and sliding it. As a result, the slider moves together with the rotor, resulting in a single rotation system, making it difficult to finely adjust the resistance value. Furthermore, due to the wear of both of the resistor and slider due to contact friction, changes in resistance and noise tend to increase as the number of rotations increases, which has a significant negative impact on the lifespan and reliability of the device. Ta.

An object of the present invention is to provide a variable resistor that eliminates the above-mentioned conventional drawbacks.

According to the present invention, a resistor is attached in an arc shape to the surface of a circular insulating substrate, and a ring-shaped conductor vertically surrounds the resistor while maintaining a certain gap therebetween;
A variable resistor characterized in that a spherical conductor that electrically rotates and presses the resistor and the conductor, and a circular rotor that presses the spherical conductor, are arranged and housed in a base and an exterior case. is obtained.

Next, embodiments of the present invention will be described with reference to the drawings.

As shown in the exploded perspective view of Figure 1, the variable resistor of this embodiment has a base 2 made of thermoplastic polyester or the like, which has a substantially circular groove in the center of the insulator, and has lead terminals 1a, 1b, and 1c. , a circular insulating substrate 4 made of ceramic or the like on which an arcuate resistor 3 is adhered, a current collecting electrode part 5 made of a ring-shaped conductor, and a spherical conductor made of a conductive elastomer such as conductive silicone rubber. It consists of a body 6, a rotor 7 made of thermoplastic polyester or the like, an O-ring 8, and an exterior case 9. A cutout portion 4a is provided in a part of the insulating substrate 4, and an opening portion 5a is provided by cutting out a portion of the ring of the current collecting electrode portion, and these portions match with the protruding portions 2b provided in the circular groove portion 2a of the base 2. The insulating substrate 4a and the current collecting electrode portion 5a are housed in the circular groove portion 2a as shown in FIG. As shown in FIG. 2, a spherical conductor 6 is installed so as to be in simultaneous contact with both the resistor 3 and the current collector electrode 5 formed on the peripheral edge of the surface of the insulating substrate 4, and the bottom of the rotor 7. It is pressurized by a stepped portion 7a with an arcuate cross section provided at the edge and rolls on the current collecting electrode portion 5 and the resistor 3 due to the rotational movement of the rotor 7. A convex protrusion 7b is provided at the center of the lower surface of the rotor 7, and a hole 4b at the center of the insulating substrate 4.
And, it presses into contact with the concave hole 2c of the base 2 to keep the rotation axis constant. Further, as shown in FIG. 3, lead terminals 1a, 1b, and 1c connected with conductive adhesive or the like extend to the outside from electrodes 3a and 3b at both ends of the resistor 3 and one end of the current collecting electrode body 5, respectively. ing. The rotor 7 is housed in an outer case 9 via an O-ring 8, and the contact portion between the base 2 and the outer case 9 is connected and fixed with an adhesive or the like 10 (FIG. 4).

As described above, according to the present invention, it is possible to obtain a small-sized, long-life, fine-adjustment, multi-rotation type variable resistor which has less wear on contact portions than conventional variable resistors and is suitable for mass production.

[Brief explanation of the drawing]

FIG. 1 is an exploded structural view of a variable resistor according to an embodiment of the present invention, and FIGS. 2, 3, and 4 are a side sectional view, a base perspective view, and an external perspective view of FIG. 1, respectively. 1a, 1b, 1c...Lead terminal, 2...Base, 2a...Circular groove, 2b...Protrusion, 2c
...Concave hole, 3...Resistor, 4...Insulating substrate,
4a... Notch, 4b... Hole, 5... Current collecting electrode, 5a... Opening, 6... Spherical conductor, 7
...Rotor, 7a...Step, 8...O ring,
9...Exterior case, 10...Adhesive.

Claims (1)

[Claims] 1. A resistor attached in an arc shape to an insulating substrate, a ring-shaped conductive plate that surrounds the resistor almost vertically with a constant gap, and electrically rotated between the resistor and the conductive plate. A spherical conductor that presses into contact with the
A variable resistor characterized in that a rotor that presses the spherical conductor is arranged and housed in a base and an exterior case.