JP2503025Y2 - Rotatable variable resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a rotary operation type variable resistor, and more particularly to a thin rotary operation type variable resistor.

[Conventional technology]

Conventionally known rotary operation type variable resistors generally have a shaft-shaped manipulator for performing a rotating operation, and a bearing provided on a frame body that covers a slider receiver. The operation element is configured to project. However, such a configuration in which the frame body is provided and the shaft-shaped operator is projected from the frame body has a disadvantage that it is difficult to reduce the size and thickness.

On the other hand, the rotary operation type variable resistor described in Japanese Utility Model Laid-Open No. 63-112310 realizes a small size and a thin shape by omitting a frame body and a shaft-shaped operator.

That is, in the conventionally proposed rotary operation type variable resistor, as shown in the partial sectional view of FIG. 3, a resistance substrate 1 formed by patterning a resistor (not shown) is a mounting plate made of a metal plate. A slider plate 3 made of a thin metal plate, which is positioned and fixed to 2 and has a slider piece (not shown) that slides on the resistor, is attached to a slider receiver 4 made of synthetic resin. The slider receiver 4 is fixed to the operating body 5 made of synthetic resin via the boss 4a. The operating body 5 is rotatably supported, for example, by caulking an eyelet 2a erected on the mounting plate 2, and the operating body 5 that covers the slider on the resistance substrate 1 is rotated. As a result, the relative position between the slider piece and the resistor is changed so that the set resistance value can be changed. In addition, in this operating body 5,
A protrusion 5a for preventing backlash is vertically provided in a ring shape,
Since the projection 5a slides on the resistance substrate 1 in accordance with the rotation of, the height position of the operating body 5 with respect to the resistance substrate 1 is kept constant and rattling does not occur.

In the rotary operation type variable resistor having such a configuration, the shaft-shaped operator, which has been provided so as to project in the conventional product, can be omitted, and the frame can also be omitted. This is a major contribution to miniaturization and thinning, especially thinning.

[Problems to be solved by the device]

However, the above-mentioned conventional proposals are not without problems.

That is, for the soldering work when mounting this type of variable resistor on the printed circuit board, reflow soldering is preferable to manual soldering in view of productivity, but the operating body 5 is heated by thermal radiation in the reflow furnace. If glass fiber or the like is mixed into the synthetic resin such as PPS as the material to improve the heat resistance, the surface roughness of the protrusion 5a for preventing backlash becomes large (coarse), and the resistance substrate 1 There is a risk of scraping off the surface of. Specifically, the risk that the insulating coat covering the lead pattern is scraped off on the surface of the resistance substrate 1 to cause short-circuiting, or the lead pattern itself is scraped off to cause a wire breakage, is shown in FIG. The variable resistor having the structure shown is unsuitable as a reflow-compatible product and was forced to be hand-soldered with poor workability.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a thin rotary operation type variable resistor which is compatible with reflow soldering and which is unlikely to cause a short or a wire breakage.

[Means for solving the problem]

The above-described object of the present invention is to provide a resistor substrate having a resistor patterned therein, a slider receiver made of synthetic resin for holding a slider piece slidingly contacting the resistor, and the slider on the resistor substrate. An operating body which is arranged at a position to cover the support and is rotatably supported by fixing the slider support; and a play preventing means for keeping a constant height position of the operating body with respect to the resistance substrate. In the rotary operation type variable resistor, wherein the operation body is rotated to change the relative position between the slider piece and the resistor, a glass fiber for increasing the heat resistance of the operation body. In addition to being made of a synthetic resin mixed with, the slider receiver is made of a synthetic resin not containing the glass fiber,
This is achieved by providing the slider receiver with a protrusion that slides on the resistance substrate as the play preventing means.

[Action]

While the operating body is exposed to high heat in the reflow furnace,
Since the slider receiver covered with the operating body is not exposed to high heat in the reflow furnace, it can be used for reflow soldering if the heat resistance of the operating body is increased by mixing glass fiber etc. If a protrusion for preventing backlash is provided on the slider support that can set the surface roughness to a small level without the need to mix in, etc., there is no risk of the protrusion scraping off the surface of the resistance board, preventing shorts and disconnections. it can.

〔Example〕

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

FIG. 1 is a sectional view of a rotary variable resistor according to an embodiment of the present invention, FIG. 2 is a plan view thereof, and parts corresponding to those in FIG. It is attached.

The variable resistor shown in FIGS. 1 and 2 prevents looseness of the operating body 5 at a plurality of positions on the outer periphery of the slider receiver 4 made of a synthetic resin material having relatively high heat resistance such as PPS or 46 nylon. Projection for
4b is hung vertically in a substantially annular shape as a whole, and a slider plate 3 made of a thin metal plate is fixed to the slider receiver 4 inside these protrusions 4b. Further, the operating body 5 arranged on the resistance substrate 1 at a position covering the slider receiver 4 and fixing the slider receiver 4 via the boss 4a is made of a synthetic resin material such as PPS or 46 nylon. The operating body 5 is made of a highly heat-resistant material mixed with glass fibers, and is not provided with a play preventing projection as in the conventional example. That is, as the operating body 5 rotates, the slider holder 4
The protrusion 4b of the slides on the resistance substrate 1,
As a result, the height position of the operating body 5 with respect to the resistance substrate 1 is kept constant so that play does not occur.

The resistance substrate 1 on which a resistor (not shown) is patterned is positioned and fixed to a mounting plate 2 made of a metal plate, and the operating body 5 is operated by caulking an eyelet 2a standing on the mounting plate 2. While being rotatably supported, the slider piece 3a extending from the slider plate 3 slides on the resistor as the operating body 5 rotates. These have the same structure as the conventional example. In other words, this variable resistor connected to the external power source via the terminal 6 changes the set resistance value by rotating the operating body 5 to change the relative position between the slider piece 3a and the resistive body. Is to do
It is a thin rotary operation type variable resistor that omits the shaft-shaped operator and frame.

Now, such a variable resistor is suitable as a reflow-compatible product because the heat resistance of the operating body 5, which is exposed to high heat in the furnace during reflow soldering, is increased due to the incorporation of glass fibers. In that case, there is no need to perform complicated manual soldering when mounting on a printed circuit board, which is a major contribution to productivity improvement. In addition, such a variable resistor is covered with the operating body 5 and is not exposed to high heat in the reflow furnace, so that the operating element 5 is prevented from rattling in the slider receiver 4 which does not need to be mixed with glass fiber. Since the protrusions 4b are provided, the surface roughness of these protrusions 4b can be reduced to the extent that there is no risk of scraping off the surface of the resistance substrate 1 during sliding, so that shorts and disconnections can be avoided and high reliability is achieved. Sex is guaranteed.

The shape and arrangement of the protrusions 4b attached to the slider receiver 4 are not limited to those in the above-mentioned embodiment, and the point is that the operation body 5 can be prevented from rattling at the position covered by the operation body 5. All you have to do is

[Effect of device]

As explained above, according to the present invention, the heat resistance of the operating body exposed to high heat in the reflow furnace is improved, and the operating body is provided with a protrusion for preventing rattling of the operating body. Since it is provided on the covered slider holder and the surface roughness of the projection is small, it is suitable as a reflowable product, and it is possible to avoid shorts and disconnections due to sliding of the projection, and to reduce the thickness. A suitable rotary operation type variable resistor can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of a rotary operation type variable resistor according to an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a partial sectional view of a conventional thin rotary operation type variable resistor. Is. 1 ... Resistor board, 3 ... Slider plate, 3a ... Slider piece, 4
...... Slider holder, 4b ... Protrusion, 5 ... Operator.

Claims (1)

(57) [Scope of utility model registration request] 1. A resistance substrate in which a resistor is patterned,
A slider holder made of a synthetic resin for holding a slider piece which is in sliding contact with the resistor, and a slider receiver arranged on the resistor substrate at a position to cover the slider holder, and the slider holder is fixed and rotated. An operating body supported movably and rattling preventing means for maintaining a constant height position of the operating body with respect to the resistance substrate are provided, and the operating body is rotated to operate the slider piece and the slide piece. In a rotary operation type variable resistor adapted to change a relative position with a resistor, the operating body is made of a synthetic resin mixed with glass fiber for enhancing heat resistance, and the slider receiver is the glass fiber. A rotary operation type variable resistor, which is made of a synthetic resin not containing any of the above, and is provided with a protrusion that is in sliding contact with the resistance substrate as the rattling prevention means on the slider receiver.