JP2500431Y2 - Semi-fixed variable resistor - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type semi-fixed variable resistor capable of finely adjusting a resistance value during or after assembling an electric circuit.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing a conventional example of a chip type semi-fixed variable resistor, which is constructed for reflow soldering. In the figure, on the upper surface of the insulating substrate 1 having the through hole 1a at substantially the center, the resistor 2 is provided around the through hole 1a.
Is printed and formed, and a terminal 3 is provided at the end of the resistor 2.
Is connected. An eyelet member 4 is inserted into the through hole 1a, and one end of the eyelet member 4 is led out to the lower surface of the insulating substrate 1 to form an intermediate terminal 5. The slider piece 6 made of a thin metal plate has a sliding contact 6a and a caulking hole 6b, and the periphery of the caulking hole 6b is a narrowed portion 6c formed into a substantially circular arm shape. The insulating annular spacer 7 disposed inside the resistor 2 on the insulating substrate 1
By mounting the narrowed portion 6c of the slider piece 6 on the upper portion and eyeleting the upper end portion of the eyelet member 4 inserted into the caulking hole 6b, the slider piece 6 rotates on the annular spacer 7. The sliding contact 6a is held in a possible state and is slidable on the resistor 2.

The semi-fixed variable resistor constructed as described above is soldered to a predetermined position on the circuit board by reflow soldering, and then the slider piece 6 is rotated by using an adjusting tool such as a driver. Then, the sliding contact 6 on the resistor 2
Since the contact position of a is changed, it can be set to a desired resistance value.

[0004]

The annular spacer 7 in the conventional semi-fixed variable resistor described above defines the height position of the narrowed portion 6c of the slider piece 6 and defines the sliding contact 6a.
In addition to the spacer function of bringing the resistor 2 into contact with the resistor 2 with an appropriate pressure, an insulating function of preventing a short circuit between the narrowed portion 6c or the eyelet member 4 and the resistor 2 is intended. Since the semi-fixed variable resistor (1) has a small diameter of about several millimeters, the assembly workability deteriorates when an extremely small member such as the annular spacer 7 is incorporated.

Therefore, the object of the present invention is to
An object of the present invention is to provide a semi-fixed variable resistor capable of reducing the number of parts and improving the workability of assembly.

[0006]

The above-mentioned object of the present invention is to provide an insulating substrate having a through hole, a resistor formed around the through hole on the insulating substrate, and inserted into the through hole. Eyelet member and a slider piece that has a sliding contact for sliding on the resistor and is held in a rotatable state by caulking the eyelet member. In a semi-fixed variable resistor whose resistance value can be adjusted by rotating it, a slider with a bottomed cylindrical shape is integrated with the slider piece.
And forming, the insulation around the through hole on the substrate <br/> the resistor insulating overcoat layer covering the inner peripheral edge portion of the printed form, the sliding by caulking the eyelet
This is achieved by pressing the squeezed portion of the armature piece onto the overcoat layer .

[0007]

According to the above means, the inner peripheral edge portion of the resistor is covered with the overcoat layer, so that the overcoat layer can be easily set to a desired film thickness to perform the spacer function and A short circuit between the inner peripheral edge of the body and the slider piece or eyelet member is prevented by the overcoat layer, so that it is not necessary to incorporate a separate annular spacer.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a semi-fixed variable resistor according to an embodiment of the present invention, in which parts corresponding to those in FIG.

In FIG. 1, an insulating overcoat layer indicated by reference numeral 8 is formed by printing around the through hole 1a on the insulating substrate 1, and the inner peripheral edge portion of the resistor 2 is formed on this overcoat layer 8. It is covered. That is, after the resistor 2 is formed by printing on the insulating substrate 1, the annular overcoat layer 8 is formed by printing so as to cover the inner peripheral portion of the resistor 2, so that the film thickness can be obtained in one printing step. A relatively thick overcoat layer 8 is obtained. Then, after the narrowed portion 6c of the slider piece 6 is mounted on the overcoat layer 8, the eyelet member 4 inserted into the caulking hole 6b is swaged by the eyelet so that the slider 6a is overlaid. The sliding contact 6a is rotatably held on the coat layer 8 so that the sliding contact 6a can slide on the resistor 2. As the material of the overcoat layer 8, a material obtained by kneading molybdenum disulfide and a phenol resin is used.
The surface of the overcoat layer 8 in contact with is excellent in lubricity and wear resistance.

As described above, in the above embodiment, the overcoat layer 8 functions as a spacer for restricting the height position of the narrowed portion 6c of the slider piece 6, and the overcoat layer 8 serves as the narrowed portion 6c. Since it has an insulating function to prevent a short circuit between the eyelet member 4 and the resistor 2, the annular spacer used in the conventional product is omitted, so that the number of parts is small and the assembling workability is improved. However, the cost can be reduced. Moreover, since the overcoat layer 8 is formed by printing so as to cover the inner peripheral edge portion of the resistor 2, it is possible to secure a necessary film thickness for the overcoat layer 8 in one printing step, which is efficient, Further, there is an advantage that even if the inner peripheral edge portion of the resistor 2 has a print drip, a high insulating effect can be expected by the overcoat layer 8. Furthermore, since this overcoat layer 8 has excellent lubricity and wear resistance, the rotational torque of the slider piece 6 can be kept smooth and constant.

The structure and operation of the parts of the above-mentioned embodiment not particularly described are the same as those of the conventional example.

[0012]

As described above, according to the present invention, the overcoat layer formed on the insulating substrate so as to cover the inner peripheral edge of the resistor has a spacer function and an insulating function, and is used in the conventional product. Since it is not necessary to separately incorporate the annular spacer that has been used, the number of parts can be reduced and the assembling workability can be improved, so that the cost of the semi-fixed variable resistor can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a semi-fixed variable resistor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a semi-fixed variable resistor according to a conventional example.

[Explanation of Codes] 1 Insulating substrate 1a Through hole 2 Resistor 4 Eyelet member 6 Slider piece 6a Sliding contact 8 Overcoat layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Akira Sueyoshi Aki Sueda, Ota-ku, Tokyo 1-7 Otsuka-cho, Alps Electric Co., Ltd. (72) Shinichi Nagai Ota-ku Ota-ku, Tokyo 1-7, Otsuka-cho Inside PUS Electric Co., Ltd. (72) Inventor Seiichi Sato 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alps Electric Co., Ltd. (72) Nobuhiro Oura No. 1-7 Otsuka-cho, Ota-ku, Tokyo Alps Electric Co., Ltd. (72) Inventor Hideyasu Hayashi 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alps Electric Co., Ltd. (56) Reference JP-A-63-168003 (JP, A)

Claims (1)

(57) [Scope of utility model registration request] 1. An insulating substrate having a through hole, a resistor formed around the through hole on the insulating substrate, an eyelet member inserted in the through hole, and sliding on the resistor. Let
That a holding has been sliding piece in a state rotatable by crimping the eyelet has a sliding contact for, can adjust the resistance value by turning operation of the sliding Doko piece In this semi-fixed variable resistor, the slider piece has a bottomed cylindrical diaphragm.
Ri section thereby integrally forming an insulating overcoat layer covering the inner peripheral edge portion of the resistor around the through hole on the insulating substrate formed by printing, the caulking of the eyelet
The pressed portion of the slider piece onto the overcoat layer.
Semi-fixed variable resistor, characterized in that contact was.