JPH0334889Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Field of application of invention] The present invention relates to a variable resistor.

[Background of the idea]

FIG. 2 is a sectional view of a conventional variable resistor.
In FIG. 2, 1 is a resistor substrate, 2 is a resistor formed on the resistor substrate 1, and 3 is the resistor substrate 1.
A cup-shaped insulating case 5 is rotatably supported on the resistor substrate 1 and has one slider sliding on the resistor 2 on one side. 6 is a rotating shaft provided with the other slider 7 that slides on the current collector ring 4 on the other surface; 8 is a mounting board that is in close contact with the outer peripheral surface of the insulating case 3 from the end of the resistor 2; A terminal extends in the direction of 9, and 10 is an intermediate terminal that projects outward from the insulating case 3 from the current collecting ring 4 and extends in the direction of the mounting board 9.

The variable resistor as described above is mounted on the mounting board 9.
After inserting the terminals 8 and intermediate terminals 10 into the holes provided on the mounting board 9 and placing them on the mounting board 9, the terminals 8 and intermediate terminals 10 are inserted into the conductive holes provided on the back surface of the mounting board 9 by dip soldering. The tip was soldered.

However, in the above structure, since the mounting board 9 and the bottom surface 3a of the insulating case 3 are arranged close to each other,
During deep soldering, flux is easily affected by flux, which rises along the outer circumferential surface of the insulating case 3 due to capillary action from the thin tube formed between the outer circumferential surface of the insulating case 3 and the terminal 8. However, if it enters the inside of the insulating case 3 from the interface A between the end face of the insulating case 3 and the resistor substrate 1, and it adheres to metal bodies such as the sliders 6 and 7 and solidifies, it will cause rotational failure and contact failure. It has the disadvantage of causing

[Purpose of invention]

The present invention aims to solve the above-mentioned conventional drawbacks, and the purpose of the present invention is to prevent flux from entering the inside of the insulating case when dip soldering is performed to attach the terminal to the mounting board. It is an object of the present invention to provide a variable resistor that can prevent such problems.

[Summary of the idea]

In order to achieve the above object, the present invention includes a resistor substrate on which a resistor is formed on one surface, an insulating case having a current collecting ring on the inner bottom surface that is coupled to the resistor substrate, and an insulating case that is housed in the insulating case. It has a rotating shaft having a slider that slides on the resistor on one side and a slider that slides on the current collector ring on the other side, and extends from the resistor board and is attached to the insulating case. In a variable resistor having a terminal that hangs down along an outer peripheral surface, the insulating case has a stepped portion on the outer peripheral surface along the terminal, and a recessed portion on the end surface that comes into contact with the resistor substrate. It is set as.

[Example of idea]

FIG. 1 is a sectional view of an embodiment of the present invention. Note that the same parts as those in the conventional example shown in FIG. 2 are given the same reference numerals and detailed explanations will be omitted.

The difference between the present invention and the conventional example is that, on the outer peripheral surface of the insulating case 3 facing the terminal 8, a stepped portion 11 having a horizontal surface 11a whose diameter gradually becomes smaller as it approaches the mounting surface of the mounting board 9; Two points are that a step portion 12 having a horizontal surface 12a is provided, and a protrusion 13 is formed on the bottom portion 3a of the insulating case 3.

According to the embodiment of the present invention, since the bottom part 3a of the insulating case 3 and the mounting board 9 are spaced apart by the protrusion 13, it is difficult to be affected by flux during deep soldering, and the insulating Case 3
By forming the stepped portions 11 and 12 as described above, the distance between the terminal 8 and the outer circumferential surface of the insulating case 3 becomes larger than that of the conventional case, and in this respect as well, the rise in flux due to capillary action is suppressed. Ru. Furthermore, since the upper part is a stepped part, the distance from the terminal to the upper part is set relatively narrow, so that it also has a function of preventing deformation of the terminal.

Note that even if some of the flux is
Even if the flux rises along the outer peripheral surface of the insulating case 3, it is prevented from rising by the horizontal surfaces 11a, 12a of the stepped portions 11, 12 of the insulating case 3, and the intrusion of the flux into the inside of the insulating case 3 is prevented.

As shown in FIG. 1, if a recess 14 is formed on the end surface of the insulating case 3 that comes into contact with the resistor substrate 1, even if flux should enter the inside of the insulating case 3, it will not accumulate in the recess 14. Preventing flux from entering the insulating case 3 is further strengthened.

[Effect of idea]

According to the present invention, a stepped portion is provided on the outer circumferential surface of the insulating case along the terminal, and a recessed portion is provided on the end surface that contacts the resistor board, so that during deep soldering, the horizontal surface of the stepped portion is provided. As a result, the rise in flux is suppressed, and by widening the distance between the insulating case and the terminal, the rise in flux due to capillary action is suppressed.Also, since a recess is provided on the end face, even if the flux rises, it will be absorbed into this recess. This prevents the intrusion into the insulating case. In addition, since the stepped portion has the function of suppressing the increase in flux, it also has the function of supporting the terminal. In addition, both the "stepped part" and the "recessed part" are part of the insulating case, and the countermeasure is by devising only the shape of the insulating case.
The present invention has the advantage that it can be easily applied to existing variable resistors without countermeasures.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a variable resistor according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional variable resistor. DESCRIPTION OF SYMBOLS 1... Resistor board, 2... Resistor, 3... Insulating case, 4... Current collection ring, 5... Rotating shaft, 6, 7...
...Slider, 8...Terminal, 9...Mounting board, 10...
...Intermediate terminal, 11, 12...Step part, 13...Protrusion, 14...Concave part.

Claims (1)

[Scope of utility model registration request] A resistor substrate on which a resistor is formed on one surface, an insulating case that is coupled to the resistor substrate and has a current collecting ring on the inner bottom surface, and a slider that is housed in the insulating case and slides on the resistor on one surface. A variable variable drive device having a rotating shaft provided with a slider that slides on the current collecting ring on the other surface, and a terminal extending from the resistor substrate and hanging down along the outer peripheral surface of the insulating case. 1. A variable resistor, characterized in that the insulating case has a stepped portion on its outer peripheral surface along the terminal, and a recessed portion on the end surface that comes into contact with the resistor substrate.