JPH0213801B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable resistor, in which an external terminal is connected to the silver electrode portion of a resistor substrate having a resistor element on one side and a continuous silver electrode portion at both ends of the resistor element. This ensures a strong connection.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In Fig. 1, reference numeral 1 denotes a cap made of plastic, which has a rotation adjustment groove 1a on the top surface into which a screwdriver (not shown) is inserted, and square holes on both sides of this groove 1a for attaching the cap to the mounting bracket 2. 1
b, 1b, and a stopper (not shown) that engages with the stopper piece 7a is integrally formed on the inner surface. 2 is a U-shaped mounting bracket, which has a central hole 2a in the center through which the oval column 9a of the shaft 9 is inserted, and upright walls 2b, 2 on both sides of this hole 2a.
b, and tapered ribs 2c are provided on the outer surfaces of the upright walls 2b, 2b, and these ribs 2c are snap-fitted into the square holes 1b, 1b of the cap 1, and the cap 1 can be attached and removed. We are trying to prevent this.

Reference numeral 3 denotes a slider having a central hole 3a in the center and an arm portion 3b on a part of the outer periphery.
a is constructed so as to be brought into sliding contact with the resistor element 5a with an appropriate pressure when completed.

Reference numeral 4 designates a seat plate made of synthetic resin, which has a central hole 4a through which the cylindrical portion 9b of the shaft 9 is inserted. Designed to be thick.

Reference numeral 5 denotes a hole 5b in which a circular resistor element 5a of a size large enough to fit into the protective wall 1c of the cap 1 is provided on one side, and a cylindrical portion 9b of the axis a is inserted through the center.
As shown in FIG. 2, the resistor element 5a is on the resistor substrate 5.
Silver electrode parts 5c, 5c are provided in communication with both ends of the silver electrode parts 5c, 5c, and a rectangular square hole 5 is provided in the center of each silver electrode part 5c, 5c, into which an external terminal mounting piece 6a, which will be described later, is inserted.
e, 5e are provided along the longitudinal direction of the silver electrode parts 5c, 5c. The size of the square holes 5e, 5e is the same as the length a and width b of the outer terminal mounting piece 6a.
Set slightly larger than a' and b', and this angle is
Both of the two longitudinal sides a of e and 5e are designed so that they are not crossed by an arbitrary radius drawn centering on the substrate. Further, a cutout 5d into which the stopper piece 7a of the intermediate terminal plate 7 is inserted is formed at the edge of the substrate at the intermediate portion between the silver electrode portions 5c, 5c.

6, 6 are mounting pieces 6a, 6a provided integrally at the tip.
The silver electrode portion 5 of the resistor substrate 5 is an external terminal having a
The mounting pieces 6a, 6a are inserted from below into the rectangular square holes 5e formed in the silver electrode portions 5c, 5c.
It is electrically and mechanically connected to c and 5c by soldering. 7 is the above-mentioned intermediate terminal board, and a shaft 9 is located in the center of the board.
It has a hole 7b into which the cylindrical part 9b is inserted, and a stopper piece 7a that engages with a stopper provided on the inner surface of the cap 1 stands vertically from the top side of the hole 7b, and a mounting leg 7c is integrally formed below. It is formed.

Reference numeral 8 denotes a contact washer made of an elastic metal material, which is formed into a spring shape with a notch 8a and a step h formed by bending in order to obtain stable electrical contact between the intermediate terminal plate 7 and the shaft 9. Reference numeral 9 denotes the aforementioned shaft, which has a disk portion 9c at its lowest part, a driver adjustment groove 9d provided in this disk portion 9c, and above which a contact washer 8, an intermediate terminal plate 7, a resistor substrate 5, and a seat. Cylindrical portion 9b inserted into each central hole 8b, 7b, 5b, 4a of plate 4
Furthermore, an oval-shaped column 9a is integrally formed above the slider 3 and inserted into each hole 3a, 2a of the mounting bracket 2.

To assemble each component configured as described above, first connect the cylindrical portion 9b of the shaft 9 to the contact washer 8 and the center holes 8a, 7b of the inner terminal plate 7, and then connect the outer terminals 6, 6 to the resistor board. 5 and the center holes 5b and 4a of the seat plate 4 in sequence. Next, a slider 3 is attached to the oval-shaped pillar portion 9a of the shaft 9 that protrudes from above the seat plate 4.
The above components are integrated by inserting the center holes 3a, 2a of the mounting bracket 2 and caulking the tip of the oval column 9a of the shaft 9 protruding from the mounting bracket 2. Furthermore, an upright wall 2 provided on the side of the mounting bracket 2
The cap 1 is attached by fitting the cap 1 into the caps b and 2b and fitting the ribs 2c and 2c into the square holes 1b and 1b of the cap 1. This completed state is shown in FIG. In this state, by rotating the cap 1 or the shaft 9, the slider 3 can be rotated in conjunction with this rotation.

Although the small variable resistor according to the present invention is constructed as described above, as the size of the product progresses, the soldering area of the silver electrode portion that connects and fixes the mounting piece of the outer terminal is reduced. Generally, ceramic material is often used as the material of the resistor board to which terminals are attached by soldering.
21 is the center line X of the substrate 20 as shown in FIG.
It is provided parallel to the −X′ axis. Here, 22
2 is a resistor element, 23 is a silver electrode portion, and 24 is an external terminal. However, as the product becomes smaller, the width l of the silver electrode parts 23, 23 becomes smaller, and the width l' of the terminal mounting piece also needs to be reduced, and as a result, the soldering strength between the outer terminal and the solder increases. However, as in the present invention, the silver electrode portion is provided on the resistor substrate 5 at an angle in the square holes 5e, 5e into which the terminal mounting pieces 6a, 6a are inserted. 5c, 5c, the longitudinal dimension a' of the terminal mounting pieces 6a, 6a can be increased, the soldering area with the solder of the outer terminal 6 is increased, and the soldering strength is at the same level as large products. As a result, the reliability of terminal strength and terminal contact, which is one of the basic functions of a variable resistor, is increased, and the effect is great.

As explained above, according to the present invention, there is provided a resistor element formed in a substantially circular shape, an electrode portion continuously extending from both ends of the resistor element, and an outer electrode portion provided on the electrode portion. The resistor substrate includes a resistor substrate having a terminal mounting hole, and the outer terminal mounting hole is formed so that the longitudinal direction of the outer terminal mounting hole extends continuously from both ends of the resistor element. By inserting the terminal mounting piece of the outer terminal into the outer terminal mounting hole and soldering it to the electrode part, the soldering strength between the outer terminal and the silver electrode part is increased, and reliability is increased. This is particularly effective for small variable resistors.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a variable resistor according to an embodiment of the present invention, Fig. 2 is a plan view of a resistor board, Fig. 3 is a sectional view when completed, and Fig. 4 is a general resistor board. FIG. 1...Cap, 2...Mounting bracket, 3...Slider, 4
... Seat plate, 5... Resistor board, 5a... Resistor element, 5
c...Silver electrode part, 5e...Outer terminal mounting hole, 6...Outer terminal, 6a...Mounting piece, 7...Inner terminal plate, 8...Contact washer, 9...Shaft, 9a...Oval column part, 9b...Cylindrical part,
9c...disc part.

Claims (1)

[Claims] 1. It has a resistor substrate consisting of a resistor element formed in a substantially circular shape, an electrode part continuously extending from both ends of the resistor element, and an external terminal mounting hole provided in the electrode part. , the outer terminal mounting hole is provided in the electrode portion such that the longitudinal direction of the outer terminal mounting hole is along the formation direction of an electrode portion formed to extend continuously from both ends of the resistor element; A variable resistor formed by inserting a terminal mounting piece of an outer terminal into a mounting hole and soldering it to the electrode part.