JPS5953682B2 - variable resistor - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in variable resistors.

Conventional trimmer type potentiometers have multiple branched sliders attached to a part of a rotating body, and the rotating body is rotated with a screwdriver or the like to simultaneously slide the sliders onto the resistor and current collector electrode. Most of them were for adjusting the resistance value.

In recent years, this type of potentiometer has been required to be more compact, but with conventional potentiometers, the number of contact points on the slider has been reduced due to the miniaturization of the structure, and the original spring characteristics of the slider itself have been lost. The contact pressure becomes unstable and the electrical characteristics are affected.

Moreover, since highly accurate sliders are required, production costs increase.

For this reason, production costs will increase if the conventional structure is made smaller and the reliability is maintained as before.

Therefore, it was not possible to achieve the objective simply by reducing the size.

Furthermore, in the conventional structure, the slider slides on the resistor, so the resistor may be damaged as the number of times it slides increases, or conversely, wear particles from the slider may adhere to the resistor. It has been difficult to maintain the initial electrical characteristics over a long period of time.

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

According to the present invention, there is provided an insulating substrate provided with a through hole and a resistor attached in an arc shape around the through hole, a cylindrical current collector electrode body with one end implanted in the through hole, and a resistor. A spherical conductor consists of a rotating body that has a protrusion in the center of a concave opening that is placed opposite to the adhered surface and that fits into a cylindrical current collector electrode body, and a spherical conductor that is sandwiched between an insulating substrate and the rotating body. A variable resistor is obtained in which the body is rolled and pressed against the inner wall surface of the concave opening of the rotary body, the surface of the resistor, and the outer surface of the cylindrical current collecting electrode body at the same time.

Furthermore, there is also a variable resistor characterized by using an elastomer in which the spherical conductor is filled with a conductive substance, and a variable resistor characterized by the inner wall corner of the rotating body being formed into an arcuate cross section. can get.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7.

FIG. 1 is a plan view of the substrate part, in which a resistor 2 such as cermet is formed in an arc shape around a circular through hole 1a provided in an insulating substrate 1 made of ceramic or the like.

Electrode portions 2a and 2b are formed at both ends of the resistor 20 at one end of the insulating substrate 1 via overlapping portions 2C and 2d of the resistor and electrode portions.

A through hole 1b and an IC are provided at approximately the center of the electrode parts 2a and 2b.
A cut-out portion 3a is provided in the through hole 1b, and one end of the lead terminals 3 and 4 shown in FIGS. 2A and B is bent over the IC.
, 4a are respectively inserted, the tip portions protruding from the insulating substrate are bent at right angles and soldered to fix them.

On the other hand, the cut-out portions 3b and 4b, which are provided by cutting and bending a part of the other ends of the lead terminals 3 and 4, are attached to the electrode portion 2a together with the cut-out portions 3a and 4b, which are fixed by pressing the side surface of the insulating substrate 1. , 2b
(See Figure 3).

Next, a cylindrical current collecting electrode body 5 is implanted in the through hole 1a of the insulating substrate 1, substantially perpendicular to the insulating substrate 1.

The bottom of the current collecting electrode body 5 is connected to a lead terminal 6 formed in advance in a stepped shape as shown in FIG. 2C.

This lead terminal 6 has a cut-out portion 6a that is partially cut-up.
A stopper 7 having an insulating property such as thermoplastic polyester is adhesively fixed to the distal end portion of the insulating substrate 1 which extends through the through hole 1d provided in the insulating substrate 1 and protrudes from the insulating substrate 1.

FIG. 3 shows lead terminals 3. 4. 6 and a current collecting electrode body 5 are shown.

A rotor 8 made of thermoplastic polyester or the like having concave openings is installed at a position facing the surface of the insulating substrate 1 on which the resistor 2 is attached, as shown in FIGS. 4A, B, C, and D. A spherical conductor 9 made of an elastomer such as conductive silicone is sandwiched between the rotor 8 and the insulating substrate 1.

A protrusion 8a is provided at the center of the opening of the rotor 8, and is inserted into the inner hole of the current collecting electrode body 5.
As shown in FIG. 5, on the lower surface side of the insulating substrate 1 on which the resistor 2 is not attached, the tip of the protruding portion 8a is crushed by heat processing to the extent that the rotor 8 can rotate, and the caulking portion 8b is formed. establish.

The conductor 9 is designed so that the inner wall surfaces 8C and 8d of the concave opening of the rotor 8, the surface of the resistor 2, and the side surface of the current collecting electrode body 5 are pressed together at the same time with an appropriate pressure.

Therefore, the conductor 9 is simultaneously rolled and pressed against the surface of the resistor 2 and the side surface of the current collecting electrode body 5 by the rotational movement of the rotor 8, so that a desired resistance value can be obtained.

Further, as shown in FIG. 6, by forming the corners of the inner wall of the concave opening of the rotor 8 into an arcuate cross section, the conductor 9 can easily roll.

FIG. 7 is a completed diagram of the embodiment of the present invention.

As described above, according to the present invention, wear of the resistor and the conductor is reduced by changing the conventional sliding motion to the rolling motion of the contact portion.

ii i provides high reliability and long life.

iii) Since the conductor is spherical, it is easy to process and suitable for mass production.

[Brief explanation of drawings]

FIG. 1 is a plan view of a substrate of a variable resistor according to an embodiment of the present invention, and FIGS. 2A, B, and C are perspective views of lead portions according to the present invention. FIG. 3 is a perspective view of the rotor according to the present invention before assembly. FIGS. 4A, B, C, and D are exploded structural cross-sectional views of the present invention. FIG. 5 is a sectional side view of FIG. 4 after assembly. FIG. 6 is a partially enlarged side sectional view of the rotor section according to the present invention. FIG. 7 is a perspective view of the entire variable resistor according to the present invention. 1...Insulating substrate, LA, LB, IC...
・Through hole, 2...Resistor, 2a, 2b...
...Electrode part, 2C, 2d...Overlapping part of resistor and electrode part, 3゜4.6...Lead terminal, 3a, 4
a, 3b, 4b, 6a... cut-and-raised part, 5...
...Collecting electrode body, 7... Stopper, 8.
...Rotor, 8a...Protrusion, 8b...
... Caulked portion, 8C, 8d ... Inner wall of concave opening, 9 ... Conductor.

Claims (1)

[Scope of Claims] 1. An insulating substrate provided with a through hole and a resistor attached in an arc shape around the through hole, a cylindrical collector electrode body with one end implanted in the through hole, and the a rotating body having a protrusion at the center of a concave opening, which is disposed opposite to the surface to which the resistor is attached, and which is fitted into the cylindrical collector electrode; and a spherical conductor sandwiched between the insulating substrate and the rotating body. A variable resistor characterized in that the spherical conductor is rolled and pressed against the inner wall surface of the concave opening of the rotating body, the surface of the resistor, and the outer surface of the cylindrical collector electrode body at the same time. 2. The variable resistor according to claim 1, wherein the spherical conductor is made of an elastomer filled with a conductive substance. 3. The variable resistor according to claim 1, wherein the inner wall corner of the rotating body is formed to have an arcuate cross section.