JP2002118005A - Rotating variable resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating variable resistor which has a long service life, can smoothly rotate over a long period, and is superior performance. SOLUTION: In this rotating variable resistor, a bearing section 2c integrated with terminals 2 works as the rotation guide of a rotating body 7. Consequently, the center of rotation of the rotating body 7 can be formed with accuracy, as compared with the conventional example. In addition, when the rotating body 7 rotates, a slider 8 slides along the same locus on a resistor 5 and the performance of this variable resistor is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary variable resistor suitable for use in various electronic devices and the like.

[0002]

2. Description of the Related Art A conventional rotary variable resistor will be described with reference to FIGS.
1 has a circular hole 31a provided in the center part and a convex part 31b provided on the outer surface. The terminals 32 and 33 are made of a metal material.
Are embedded in and attached to the substrate 31, and have one end protruding outward from the side surface of the substrate 31 and the terminal portions 32 a, 33 a
Is formed, and the other end is exposed from the surface of the substrate 31 to form exposed portions 32b and 33b.

[0003] A current collector 34 obtained by firing a paste containing a good conductive material such as silver is formed on the surface of the substrate 31 and is provided annularly around the hole 31a. It is connected to the exposed part 32b of the terminal 32. Also,
The resistor 35 is formed on the surface of the substrate 31 and is formed in an arc shape provided on the outer periphery of the annular current collector 34.
Further, two lead portions 36 obtained by firing a paste containing a good conductive material such as silver are formed on the surface of the substrate 31, and one end is connected to the resistor 35, and the other end is exposed to the terminal 33. It is connected to the section 33b.

A rotating body 37 made of synthetic resin formed by injection molding has a cylindrical shaft portion 37a and a hole 37b provided at the center of the shaft portion 37a. 37 is made of a metal plate and has contact pieces 38a, 38b.
Is fixed. The rotating body 37 is rotatably mounted by inserting the shaft portion 37 a into the hole 31 a of the board 31, and the one contact piece 38 of the slider 38.
a is connected to the current collector 34, and the other contact 38b is connected to the resistor 3
5 slides.

A cover 3 made of a synthetic resin molded product
Numeral 9 has a cup shape, and is attached to the substrate 31 by an appropriate means such as snapping so as to cover the slider 38, the resistor 35, and the current collector 34. In the conventional rotary variable resistor having such a configuration, the convex portion 31b of the substrate 31 and the terminal portions 32a and 33a of the terminals 32 and 33 are placed on a printed circuit board (not shown). Are mounted on a printed circuit board by surface mounting.

The operation of such a conventional rotary variable resistor is performed by inserting an operating member (not shown) into a hole 37b of a shaft portion 37a and rotating the rotating body 37, whereby the slider 38 rotates. The contact piece 38a slides on the current collector 34,
The contact piece 38b slides on the resistor 35, and the terminals 32 and 3
3, the resistance value can be varied. When the rotating body 37 rotates, the shaft 37a made of synthetic resin is used.
And the substrate 31 made of synthetic resin, the rotating body 37 rotates.

[0007]

In the conventional rotary variable resistor, the shaft portion 37a of the rotating body 37 made of synthetic resin is guided by the hole 31a of the substrate 31 made of synthetic resin and rotates. When the resin slides with each other,
There is a problem that not only wear is fast and life is not extended, but also smooth rotation is not possible. Further, the shaft portion 37a is rotated by using the hole 31a made of synthetic resin as a guide, but the accuracy of the hole 31a is poor due to sink marks or the like.
During rotation, there is a problem that the slider 38 does not follow the same locus on the resistor 35, resulting in poor performance.

Accordingly, an object of the present invention is to provide a rotary variable resistor that has a long life, can rotate smoothly over a long period of time, and has good performance.

[0009]

As a first means for solving the above problems, a substrate made of a synthetic resin having a hole in the center, a current collector formed on the surface of the substrate, A resistor formed on the surface of the substrate, a metal terminal embedded in the substrate and connected to the current collector, and a slider that slides on the resistor and the current collector are attached. A rotating body having a shaft portion inserted into the hole of the substrate, wherein the terminal has a cylindrical bearing portion formed integrally therewith, and the bearing portion is provided on the substrate. A configuration in which the shaft is inserted into the bearing, and the surface is slid between the shaft and the bearing, so that the rotating body rotates. And

[0010] As a second solution, an outer peripheral surface of the bearing portion is supported in close contact with the substrate. Further, as a third solution, the bearing portion has a configuration in which a tip portion protrudes toward a side opposite to a surface side of the substrate on which the current collector is provided. As a fourth solution, the tip portion of the bearing portion protrudes outward from an end of the hole.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings of the rotary variable resistor of the present invention, FIG. 1 is a front view of the rotary variable resistor of the present invention, and FIG. 2 is a side view of the rotary variable resistor of the present invention. 3 is a sectional view taken along line 3-3 in FIG. 1, FIG. 4 is a plan view of a substrate relating to the rotary variable resistor of the present invention, and FIGS. 5 and 6 are manufacturing methods of the rotary variable resistor of the present invention. FIG.

Next, the configuration of the rotary variable resistor according to the present invention will be described with reference to FIGS. 1 to 4. The substrate 1 made of a synthetic resin molded product has a circular hole 1a provided at the center portion. ,
And a convex portion 1b provided on the outer surface. The terminal 2 is made of a metal material. The terminal 2 is buried and attached to the substrate 1. One end of the terminal 2 protrudes outward from a side surface of the substrate 1 to form a terminal portion 2 a. Is exposed from the surface of the substrate 1 to form an exposed portion 2b,
A cylindrical bearing portion 2c formed integrally with the terminal 2 at the center by drawing is provided to be exposed on the inner surface of the hole 1a.

The bearing 2c is supported with its outer peripheral surface in close contact with the substrate 1, and the inner peripheral surface of the bearing 2c is exposed in the hole 1a. Of the substrate 1 provided with the current collector 4
Projecting toward the opposite side to the front side of the hole 1a, and the tip end projects outward from the end of the hole 1a. Multiple terminals 3
Is made of a metal material. The terminal 3 is embedded in and attached to the substrate 1, one end of the terminal 3 protrudes outward from a side surface of the substrate 1, and a terminal 3 a is formed. The exposed portion 3b is formed by being exposed from the surface.

A current collector 4 obtained by firing a paste containing a good conductive material such as silver is formed on the surface of the substrate 1,
An annular portion is provided around the hole 1a, and the exposed portion 2b of the terminal 2 is formed within the range of the annular width A.
Is connected to Further, the resistor 5 is formed on the surface of the substrate 1 and is formed in an arc shape provided on the outer periphery of the annular current collector 4, and both end portions 5 a are arranged in a state of being close to each other.

A lead portion 6 obtained by baking a paste containing a good conductive material such as silver is formed on the surface of the substrate 1 and is bent along the outer shape of the resistor 5. 6a, an end 6b connected to a lower portion of the end 5a of the resistor 5, and a connection 6 connected to the exposed portion 3b of the terminal 3.
c. The exposed portion 2b of the first terminal 2 is located at a position opposite to the end 5a of the resistor 5 with the hole 1a interposed therebetween.
Is formed.

The rotating body 7 made of synthetic resin has a cylindrical shaft portion 7a and a hole 7b provided at the center of the shaft portion 7a. The slider 8 having the contact pieces 8a and 8b is fixed. The rotating body 7 is rotatably mounted with the shaft portion 7a inserted into the hole 1a of the substrate 1 and one contact piece 8a of the slider 8
Is slid on the current collector 4, and the other contact piece 8 b is slid on the resistor 5.

At this time, the shaft portion 7a is guided by the cylindrical bearing portion 2c of the terminal 2 and slides on the surface between the shaft portion 7a and the bearing portion 2c so that the rotating body 7 rotates. Has become. The contact piece 8a is connected to the current collector 4 excluding the exposed portion 2b.
It slides up, that is, within the range of the sliding locus S1, and the contact piece 8
b slides on the resistor 5 within the range of the sliding locus S2.

A cover 9 made of a synthetic resin molded product
Has a cup shape, and is attached to the substrate 1 by an appropriate means such as snapping so as to cover the slider 8, the resistor 5 and the current collector 4. Then, the rotary variable resistor of the present invention having such a configuration, as shown in FIG.
On the printed board 10, the projection 1 b of the board 1 and the terminals 2 a and 3 a of the terminals 2 and 3 are placed, and the printed board 1
0 is mounted on the surface. At this time,
The distal end of the cylindrical bearing portion 2c is in a state of protruding into the hole 10a of the printed circuit board 10.

The operation of the rotary type variable resistor according to the present invention is performed by inserting an operation member (not shown) into the hole 7b of the shaft portion 7a and rotating the rotating body 7, whereby the slider 8 is moved. Rotating, the contact piece 8a slides on the current collector 4 within the range of the sliding locus S1, and the contact piece 8b slides on the resistor 5 within the range of the sliding locus S2. The resistance value is varied between 2 and 3.

Further, as shown in FIG. 5, the method of manufacturing the rotary variable resistor according to the present invention is such that a hoop material F made of a metal plate is punched out, and a terminal portion 2a and an exposed portion formed by bending are formed. 2b and a terminal 3 having a terminal portion 3a and an exposed portion 3b formed by bending are formed in a state of being connected to the hoop material F, and the terminal 2 is integrally formed with the hoop material F by drawing. The shape of the bearing 2c is formed.

Next, as shown in FIG.
a to protrude outward and to expose the exposed portions 2b, 3b from the surface, by molding the substrate 1 of synthetic resin.
3 is buried, and the bearing portion 2c is buried in a state where the outer peripheral surface thereof is tightly supported by the substrate 1.

The insert molding of the terminal 2 is performed as follows.
The tip protruding outward from the hole 1a is held by a molding die (not shown), and the hole of the bearing 2c is
Insert molding is performed with a part of the molding die inserted and the bearing 2c positioned. For this reason, the hole 1a can be formed with high precision. Thereafter, the current collector 4 and the resistor 5 are formed on the surface of the substrate 1 by printing or the like, whereby the rotary variable resistor of the present invention is manufactured.

[0023]

In the rotary variable resistor according to the present invention, the terminal 2 has a cylindrical bearing 2 formed integrally therewith.
The bearing 2c is provided so as to be exposed on the inner surface of the hole 1a of the substrate 1, the shaft 7a of the rotating body 7 is inserted into the bearing 2c, and the shaft 7a and the bearing 2c Between the synthetic resin shaft 7a and the metal bearing 7a, so that the rotating body 7 is rotated. Thus, a rotary variable resistor that has a long life and can rotate smoothly for a long time can be provided. Further, since the bearing portion 2c is formed of metal, the center of rotation can be formed with higher precision than in the past, and during rotation, the slider 8 slides on the same locus on the resistor 5, A rotary variable resistor having good performance can be provided.

Since the bearing 2c integral with the terminal 2 serves as a rotation guide for the rotating body 7, the number of parts does not need to be increased. Further, by providing the bearing portion 2c, the bearing portion 2c can be accurately positioned by the forming die inserted into the bearing portion 2c, and the accurate hole 1
a can be formed.

Further, since the outer peripheral surface of the bearing portion 2c is supported in close contact with the substrate 1, the support of the bearing portion 2c is strengthened, and a reliable rotation of the rotating body 8 can be obtained.

Since the tip of the bearing 2c protrudes toward the side opposite to the surface of the substrate 1 on which the current collector 4 is provided, the tip of the bearing 7c is inserted when the shaft 7a is inserted into the bearing 2c. A good assembly can be obtained without hitting the shaft 7a.

Further, since the tip of the bearing 2c projects outward from the end of the hole 1a, the support of the shaft 7a is stabilized, and the projected tip can be held by the forming die.
a with high precision of a is obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a rotary variable resistor according to the present invention.

FIG. 2 is a side view of the rotary variable resistor according to the present invention.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a plan view of a substrate according to the rotary variable resistor of the present invention.

FIG. 5 is an explanatory view showing a method of manufacturing a rotary variable resistor according to the present invention.

FIG. 6 is an explanatory view showing a method of manufacturing a rotary variable resistor according to the present invention.

FIG. 7 is a sectional view of a main part of a conventional rotary variable resistor.

FIG. 8 is a plan view of a substrate according to a conventional rotary variable resistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1a Hole 1b Convex part 2 Terminal 2a Terminal part 2b Exposed part 2c Bearing part 3 Terminal 3a Terminal part 3b Exposed part 4 Current collector 5 Resistor 5a End part 6 Leading part 6a Curved part 6b End part 6c Connection part 7 rotation Body 7a Shaft 7b Hole 8 Slider 8a Contact piece 8b Contact piece 9 Cover 10 Printed circuit board 10a Hole A Width S1 Sliding locus S2 Sliding locus F Hoop material

Claims (4)

[Claims] A substrate made of a synthetic resin having a hole in the center, a current collector formed on the surface of the substrate, a resistor formed on the surface of the substrate, and a resistor embedded in the substrate; A metal terminal connected to the current collector, and a rotating body having a shaft that is fitted with a slider that slides on the resistor and the current collector and that is inserted into the hole of the substrate; The terminal has a cylindrical bearing portion formed integrally with the terminal, and the bearing portion is provided so as to be exposed on the inner surface of the hole of the substrate, and the shaft portion is provided inside the bearing portion. A rotary variable resistor, wherein the rotary member is rotated by performing surface sliding between the shaft portion and the bearing portion. 2. The rotary variable resistor according to claim 1, wherein an outer peripheral surface of said bearing portion is supported in close contact with said substrate. 3. The rotary variable type according to claim 1, wherein said bearing portion has a tip portion protruding toward a side opposite to a surface side of said substrate provided with said current collector. Resistor. 4. The rotary variable resistor according to claim 3, wherein said tip portion of said bearing portion protrudes outward from an end of said hole.