JPH0754769B2 - Small variable resistor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small variable resistor used in various electric devices.

2. Description of the Related Art The structure of a conventional general small variable resistor is as shown in FIG. That is, in the past, in order to rotatably attach the slider 1 to the resistor substrate 2, the rear surface side of the resistor substrate 2 opposite to the resistor surface 2a with which the tip portion 1a of the slider 1 is in sliding contact. From the shaft part 3a of the mounting bracket 3 to the cylindrical part 4a of the middle terminal 4
And the resistor substrate 2 into the cylindrical portion 2a.
The slider 1 was crimped by the upper end of the shaft portion 3a of the mounting member 3 protruding from the surface of the slider 1. Further, the cap 5 has been attached to the slider 1 by press fitting, snapping or the like when a request for automatic adjustment and a dustproof type is received. 5a is a driver groove provided in the cap 5.

Problems to be Solved by the Invention However, such a configuration of the conventional small variable resistor has a problem that the number of parts and the number of assembling steps increase, and it is difficult to reduce the cost.

Therefore, the present invention is intended to eliminate the above-mentioned conventional defects, and to provide a small variable resistor which can be manufactured at low cost by reducing the number of parts, improving workability. The purpose is.

Means for Solving the Problems To achieve this object, the small variable resistor of the present invention is
Molded resistor in which resistors with external terminals attached to both ends are molded so that a part of the resistors are exposed on the surface, and a slider made of a conductive material having upper and lower protrusions having a spring property. And a plate-shaped middle terminal made of a conductive material are integrally molded with resin at the central portion thereof, and a rotation shaft made of this resin is rotatable integrally with the slider with respect to the middle terminal. And an engaging means portion provided on a side surface of the molded resistor and an engaging means portion provided on an end surface portion of the middle terminal forming the integrally molded article. The slider is integrally assembled by engaging means such as caulking, and one protrusion of the slider comes into contact with the middle terminal and the other protrusion of the slider forms a surface of the resistor constituting the molded resistor. It is configured to touch.

According to the small variable resistor of the present invention configured as described above, the slider, the intermediate terminal, and the rotary shaft are integrally molded,
In addition, all the parts can be assembled by directly attaching the middle terminals that make up the integrally molded product to the molded resistor, so the number of parts can be significantly reduced, and the assembly can be simplified and the cost is low. Can be manufactured.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a small variable resistor according to an embodiment of the present invention in a completed product state, and FIG. 2 is an exploded perspective view of the same.
3 (a) and 3 (b) are perspective views showing the states of the manufacturing steps of the resistor portion that constitutes the variable resistor, and FIG. 4 (a) and FIG.
(B) and (c) are sliders that also constitute a variable resistor,
FIG. 3 is a perspective view showing the middle terminal and an integrally molded product obtained by integrally molding them, with the vertical direction reversed from the other drawings.

First, in FIGS. 3A and 3B, 6 is a horseshoe-shaped resistor, and resistor electrodes 7 made of silver electrodes are formed at both ends of the resistor 6. The outer terminal 8 is attached to the resistor electrode 7 by eyelet caulking or the like to maintain electrical continuity. The resistor 6 having the outer terminal 8 attached thereto is made of resin to form a through hole 9 and a concave projection 10 provided on a pair of opposite side surfaces so as to project outward.
a, resistor surface 6 exposed in a range that matches a certain rotation angle
A molded resistor 10 is formed by molding so that most of the outer terminals 8 are provided on a and outside. At this time, the molded resistor 10 is placed on the surface 6a of the resistor 6.
Has a recess at the center of the upper surface so that the through hole 9 is provided at a position lower than the outer shell.
Is formed.

Next, FIG. 4 (a) shows a slider 11 made of a conductive material, and the slider 11 has a non-circular center at a substantial center thereof for forming a rotation stopping structure with respect to a rotation shaft described later. Having holes 12,
In addition, a protruding portion 11a having a spring property protruding downward is provided in the peripheral portion.
Is provided, and a protruding portion 11b having an upwardly protruding spring property is provided near the central hole 12 with a constant gap (slit) from the peripheral protruding portion 11a.
These projecting portions 11a, 11b are such that at the stage where each component is assembled as described later, one projecting portion 11a comes into contact with the resistor surface 6a and the other projecting portion 11b comes into contact with a middle terminal described later. Has become.

Next, FIG. 4 (b) shows a plate-shaped middle terminal 13 made of a conductive metal material. The middle terminal 13 has a circular central hole 14 substantially at the center of its flat plate portion, and also has a circular central hole 14. A pair of side walls is provided with a rising wall 13a projecting downward, and the mold resistor 1 is provided on an end face portion of the rising wall 13a.
Three protrusions 13 for engaging and fixing the concave protrusion 10a of 0
b is provided. Further, a terminal portion 13c protruding downward is provided on one of the opposite side edges of the middle terminal 13, and an upward protruding cut-and-raised portion 13d is provided on the other side edge of the middle terminal 13. ing.

Next, the integrally molded product 15 shown in FIG. 4 (c) and FIG.
Is integrally molded with resin in the central portion by the central hole 12 of the slider 11 and the central hole 14 of the middle terminal 13 (outsert molding).
The rotary shaft 6 is formed by providing an upper shaft portion 16a and a lower shaft portion 16b on both upper and lower surfaces of the middle terminal 13, and the upper shaft portion is provided. The diameter of 16a is larger than that of the lower shaft portion 16b. Above rotary shaft 16
The upper shaft portion 16a and the lower shaft portion 16b which constitute the above are made of the same resin body as described above.
And are molded so that they can rotate freely as a unit. Further, a groove 16c for adjusting a driver is formed at the tip of the upper shaft portion 16a, and a rotation stopping portion 1 that comes into contact with the cut-and-raised portion 13d of the middle terminal 13 in the rotation direction is formed on a part of the outer peripheral portion.
6d is provided, and a driver adjustment groove 16e is formed at the tip of the lower shaft portion 16b.

In the integrally molded product 15, the slider 11 is outserted with resin in a state of being in pressure contact with the middle terminal 13, and the protruding portion 11b protruding above the slider 11 has the middle terminal 13 It has a spring property and contacts with it to achieve electrical conduction.

FIG. 1 and FIG. 2 show a completed product in which the above-mentioned parts are assembled and a state before completion. A mold resistor 10 as shown in FIG. 2 and an integrally molded product 15 are combined to form a completed product. . In these drawings, as described above, the protrusions 13b provided on the end face portions of the pair of opposite sides of the middle terminal 13 in which the slider 11 is rotatably attached by the rotary shaft 16 made of resin, While being fitted to the concave protrusion 10a on the side surface of the molded resistor 10 formed in a size and shape that match it,
The lower shaft portion 16b of the rotary shaft 16 has the through hole 9 of the molded resistor 10.
The integrally molded product 15 is attached to the molded resistor 10 by means such as crimping the protruding portion 13b. In this assembled state, the upper surface portion of the molded resistor 10 is covered with the flat plate portion of the middle terminal 13, and the peripheral protrusion portion 11a protruding downward of the slider 11 is formed on the resistor surface 6a. It comes into contact with the spring property. Further, as shown in FIG. 1, a ring-shaped protrusion 10b is provided around the through hole 9 on the lower surface side (back surface of the resistor 6 side) of the molded resistor 10 so that the driver can be removed from the back surface. A guide is provided for inserting into the groove 16e for adjusting the driver.

As described above, the small variable resistor of the present embodiment is configured such that one protrusion 11a of the slider 11 contacts the resistor surface 6a with a spring property and the other protrusion 11b.
Has a spring-like contact with the middle terminal 13, and two outer terminals 8 and a lead-out terminal portion 13c of the middle terminal 13 are drawn out to the outside so that the apexes of the tips thereof form a triangle.
Further, when the driver adjustment grooves 16c and 16e provided at the upper and lower ends of the rotary shaft 16 made of resin outsert-molded to the external terminal 13 are rotated by, for example, a screwdriver, the sliding The protrusion 11a of the child 11 is the resistor surface 6a.
Slide on. This makes it possible to change the resistance value. At this time, the rotation stopping portion 16d provided on the upper shaft portion 16a of the rotating shaft 16 contacts the cut-and-raised portion 13d of the middle terminal 13, whereby the rotation range of the rotating shaft 6 is restricted.

In the above embodiment, the integrally formed product 15 is obtained by engaging and fixing the three protrusions 13b provided on the end face of the middle terminal 13 of the concave protrusion 10a provided on the side surface of the molded resistor 10.
Although the case of mounting is explained, it is needless to say that this may be integrally assembled by other engaging means. Further, the lower shaft portion 16b of the rotary shaft 16 is fitted in the through hole 9 of the molded resistor 10 and the driver adjustment groove 16e is provided at the tip of the lower shaft portion 16b. It is not necessary to fit the shaft portion 16b into the through hole 9 and, in that case, a groove 16e for adjusting the driver.
And the through hole 9 will be omitted.

EFFECTS OF THE INVENTION As described above, the small variable resistor of the present invention is configured, and the slider, the intermediate terminal, and the rotary shaft are integrally molded, and the intermediate terminal that constitutes the integrally molded product is All components can be assembled by directly attaching to the mold resistor, so the number of components can be significantly reduced.
Assembling can be simplified and reliability of electrical contact between the two is improved by bringing another protrusion provided near the hole in the center of the slider into contact with the middle terminal. It is possible to obtain the effect that the small variable resistor aiming at the above can be manufactured at low cost. Further, the structure is such that it is possible to easily improve the functions such as the dustproof structure and the double-sided adjustable structure, which has a high industrial utility value.

[Brief description of drawings]

FIG. 1 is a sectional view of a finished product showing an embodiment of a small variable resistor according to the present invention, FIG. 2 is an exploded perspective view showing the same semi-finished product, and FIGS. 3 (a) and 3 (b). FIG. 4 is a perspective view showing a state of manufacturing steps of a resistor portion constituting the variable resistor,
(A), (b) and (c) are perspective views showing a slider, a middle terminal, and an integrally molded product integrally formed by integrally forming the slider, which also constitute the variable resistor, in the vertical direction opposite to the other drawings. ,
FIG. 5 is an exploded perspective view showing a small variable resistor in a conventional example. 6 ... resistor, 6a ... resistor surface, 7 ... resistor electrode,
8 ... Outer terminal, 9 ... Through hole, 10 ... Molded resistor,
10a ... Engaging means (concave projection), 10b ... Ring-shaped projection, 11 ... Slider, 11a ... Spring projection, 11b
...... Other protrusions having spring properties, 12 ...... central hole, 13 ...... middle terminal, 13b ...... engagement means (three protrusions), 13d ...... cut and raised part, 14 ...... center Hole, 15 ... Integrally molded product, 16 ... Rotary shaft, 16c, 16e ... Groove for adjusting driver, 16d ... Rotation stop.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuyoshi Onda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References

Claims (4)

[Claims] 1. A molded resistor, in which a resistor having external terminals attached to both ends is molded with resin so that a part of the resistor is exposed on the surface, and a protrusion having a spring property are provided in the peripheral portion. The slider, which is made of a conductive material and has a hole in the center, and the plate-shaped middle terminal, which is made of a conductive material and has a hole in the center, are integrally molded by resin, and In the vicinity of the hole of (4), another protrusion that comes into contact with the vicinity of the hole at the center of the middle terminal is provided, and the rotation shaft made of this resin is integrally formed with the slider with respect to the middle terminal. An integrally molded product that is molded so as to be rotatable, and an engagement means portion provided on the side surface of the molded resistor and an engagement member provided on the end face portion of the middle terminal that constitutes the integrally molded product. The coupling means and the engaging means such as caulking are integrally assembled. Is, small variable resistor the projections, characterized in that a structure in contact with the surface of the resistor constituting the mold resistor together with the slider is in contact with the in terminal. 2. A cut-raised portion is provided in a part of the middle terminal in a direction opposite to a side where the slider is located, and a part of an outer peripheral portion of the rotary shaft can abut the cut-raised part in a rotational direction. 2. A small variable resistor according to claim 1, wherein the variable rotation resistor is provided to restrict the rotation angle of the rotary shaft. 3. A through hole is provided in the center of the molded resistor, a lower end of a rotary shaft is fitted in the through hole, and a groove for driver adjustment is provided at the lower end and the upper end of the rotary shaft. The small variable resistor according to claim 1. 4. A small variable resistor according to claim 3, wherein a ring-shaped protrusion is provided around the through hole on the rear surface of the molded resistor on the resistor side.