JPH0138886Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a variable resistor equipped with a heat sink and through which a relatively large current flows. The present invention relates to a substrate support mechanism with a regulation function.

[Technical background]

Products that draw relatively large currents use large variable resistors called high-voltage volumes. The case of this type of variable resistor consists of a pair of heat sinks and a resin frame positioned between them. In this case, a rotary operating body is provided which includes a substrate having a resistor attached to its surface and a slider that slides into contact with the resistor. Furthermore, a mechanism for regulating the rotation angle of the rotary operating body is required within the case.

However, in the past, the rotation angle regulating mechanism was provided separately within the case, which resulted in a complicated mechanism within the case, which had the disadvantage of contributing to an increase in the size of the case itself.

[Purpose of this invention]

The present invention was developed by focusing on the above-mentioned conventional problems, and uses an extremely simple mechanism to support the plate within the case, and utilizes this support structure to adjust the rotation angle of the rotary operating body. It is an object of the present invention to provide a substrate support mechanism for a variable resistor that allows regulation of the resistance.

[Structure of the present invention]

In the substrate support mechanism according to the present invention, a case is formed by a heat dissipation plate and a frame body, and within this case, a substrate having a resistor and a rotary operation body having a slider that slides in contact with the resistor are disposed. In the built-in variable resistor, a recess is formed in the periphery of the substrate, and a protrusion is provided on the inner surface of the heat sink to fit into the recess and position the substrate, and This projection is characterized by being inserted into a rotation angle regulating groove formed in the rotary operating body.

[Example of the present invention]

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

Figure 1A (top view), Figure 1B (front view), Figure 1
Fig. C (side view) and Fig. 2 (perspective view) show the assembled state of the variable resistor according to the present invention, Fig. 3 shows an exploded perspective view of the case, and Fig. 4 (exploded perspective view), FIG. 5 (perspective view) shows the installed state of the internal mechanism, and FIG. 6 shows the rotational operation member.

Reference numeral 1 in the figure is a frame, and heat sinks 2 are provided on both sides of the frame 1. The frame body 1 is made of resin, and the heat sink 2 is made of aluminum die-casting or the like.

As shown in FIG. 5, a ceramic substrate 3 is fixed to the inner surface of the heat sink 2 forming both side surfaces. An electrode 4 is provided at the center of the inner surface of this substrate 3. This electrode 4 is formed of a thin leaf spring or the like. Further, a circular resistor 5 is attached and formed on the substrate 3. Terminals 6a, 6b, 6c are provided on the lower surface of the substrate 3, and electrodes 4
The lower end of resistor 5 is connected to terminal 6a, and both ends of resistor 5 are connected to terminals 6b and 6c. As shown in FIG. 4, a hole 3a is formed in the center of the substrate 3, and a recess 3b, a recess 3c, and a protrusion 3d located between them are provided at the periphery. The recesses 3b, 3c and the protrusion 3d are formed on both sides of the substrate 3. On the other hand,
On the inner surface of the heat sink 2, there are protrusions 2a and 2b on the left side of the figure across the central hole 2f, and a protrusion 2b on the right side.
and 2d are integrally provided. There is a positioning space 2c between the projections 2a and 2b on the left side, and a positioning space 2c between the projections 2b and 2d on the right side.
is formed. Note that a regulating protrusion 2e is integrally provided at the tip of one protrusion 2d on the right side. This regulating protrusion 2e is for setting the rotation angle of a rotary operating body 7, which will be described later.

When the substrate 3 is attached to the inner surface of the heat sink 2, the projections 2a, 2b and 2b, 2 on the heat sink 2 side
The recesses 3d and 3c of the substrate 3 are fitted into the positioning space 2c, and the projection 3d is fitted into the positioning space 2c.
The position is determined by fitting the two.

Furthermore, as shown in FIG. 3, an operating chamber A is formed inside the frame 1, and a rotary operating body 7 is housed within this operating chamber A. This rotating operation body 7
is made of resin, and a shaft 7a is integrally provided at the center of both sides. This shaft 7a is supported by the central hole 2f of the heat sink 2, and the rotary operating body 7 is rotatably mounted. In addition, an operation window 1b (see Fig. 3) is bored in the center of the front surface 1a of the frame 1.
The circumferential surface of the rotary operating body 7 slightly protrudes from the operating window 1b.

Furthermore, grooves 7b are formed on both side surfaces of the rotary operating body 7. The groove 7b is formed in an arc shape with a predetermined angle length around the shaft 7a. When the rotary operating body 7 is attached, the regulating protrusion 2e provided on the inner surface of the heat sink 2 enters the groove 7b, and the rotation angle of the rotary operating body 7 is set in accordance with the forming angle of the groove 7b. It is becoming more and more common.

Further, conductive plates 8 are fixedly provided on both sides of the rotary operating body 7. A portion of the conductive plate 8 extends around the shaft 7a to form a contact portion 8b, and furthermore, a pair of sliders 8a are integrally formed on the outer periphery of the contact portion 8b. This slider 8a is the rotary operating body 7
It is formed by rising from the side of the In the assembled state, the electrode 4 provided on the substrate 3 is in sliding contact with the contact portion 8b, and the slider 8a is in contact with the resistor 5 on the substrate 3.
It is designed to come into sliding contact with the

As shown in FIG. 3, positioning surfaces 1c are formed on both side surfaces 1e of the frame 1. This positioning surface 1c is formed in a concave shape from the side surface 1e of the frame 1. Further, a notch 1d continuous to the positioning surface 1c is formed on both sides of the side surface 1e. On the other hand, projections 2g are integrally provided on both sides of the inner surface of the heat dissipation plate 2. Further, a connecting surface 2h is formed on the outer surface of the projection 2g. In the assembled state, the projection 2g is fitted into the notch 1d of the frame 1, and the connecting surface 2h is located on the same plane as the positioning surface 1c. Furthermore, heat sink 2
Protrusions 2i and 2j are provided on both side ends of.
This one protrusion 2j is connected to the connecting surface 2h of the protrusion 2g.
It is located at a slightly lateral position. Further, a locking groove 2 is provided between both protrusions 2i and 2j.
k is formed.

Mounting fittings 11 are attached to both sides of the frame 1. This mounting bracket 11 is formed from a metal plate, and has a pair of legs 1 at its base.
1a is provided. The inner surface of this leg portion 11a abuts against the positioning surface 1c of the frame 1 and the connecting surface 2h of the heat sink 2. At this time, positioning surface 1c
is slightly lower than the side surface 1e of the frame 1, so the outer surface of the leg portion 11a is approximately flush with the side surface 1e.

The frame body 1, heat sink 2 and mounting bracket 11
is fixed by a fixture 12. A pair of fixing pieces 12a are bent and formed on this fixing metal fitting 12, and claws 1 are provided on both sides of the upper end of the fixing pieces 12a.
2b is provided.

Next, assembly of the variable resistor with the above configuration will be explained.

Two substrates 3 are attached with the rotary operating body 7 in between, and each substrate 3 is attached to the inner surface of each of the pair of heat sink plates 2, as shown in FIGS. 4 and 5. As mentioned above, at this time, the recesses 3b provided in the substrate 3,
3c is fitted onto the projections 2b, 2c and the projection 2b2d on the heat sink 2 side for positioning. Then, the rotary operation body 7 is attached to the inside of the board 3. This rotary operating body 7 is provided within the operating chamber A of the frame body 1. That is, the shaft 7a of the rotary operating body 7 is passed through the hole 3a of the substrate 3 and inserted into the hole 2f of the heat sink 2. At this time, the regulating protrusion 2e of the heat sink 2 is inserted into the groove 7b of the rotary operating body 7. Further, the electrode 4 provided on the substrate 3 contacts a contact portion 8b provided on the rotary operating body 7, and the slider 8a on the rotary operating body 7 side contacts the resistor 5 of the substrate 3.

Moreover, when the frame 1 and the heat sink 2 are combined, the projection 2g of the heat sink 2 is fitted into the notch 1d of the frame 1, as shown in FIG. After that, for the positioning surface 1c and the connecting surface 2h, which have become the same surface,
The inner surfaces of the legs 11a of the mounting fittings 11 are brought into contact with each other (the contact portions are shown by cross hatching). The outer surface of this leg portion 11a is located on the same plane as the side surface 1e of the frame body 1. Furthermore, a projection 2i provided on the heat sink 2 is fitted into a side surface 1e of the frame 1.

Thereafter, the fixture 12 is fitted onto the frame 1. At this time, the inner surface of the tip of the fixing piece 12a (the cross-hatched portion) covers the leg portion 11a of the mounting bracket 11 from the outside. Further, the outer surface of the side end portion 12c of the fixed piece 12a is pressed by the projection 2j of the heat sink 2. That is, the side end portion 12c
is inserted into the gap between the projections 2g and 2j of the heat sink 2 (see FIG. 2). Further, the claw 12b provided on the fixed piece 12a is fitted into the locking groove 2k of the heat sink 2. By bending this claw 12b against the outer surface of the heat sink 2, the frame 1, the heat sink 2, and the mounting bracket 11 are fixed together.

When attaching the variable resistor assembled as described above to the hole 20a of the panel 20 (see FIG. 1B), the variable resistor is inserted into the hole 20a from the direction of the terminals 6a, 6b, and 6c. At this time, the mounting bracket 11 bends inward once, and then the mounting bracket 1
1 is opened and locked to the inner surface of the panel 20. The variable resistor is thereby attached to the panel 20. Furthermore, when operating this variable resistor, the rotary operating body 7 protruding from the front surface 1a of the frame 1 is rotated. Thereby, the slider 8a slides on the resistor 5 of the substrate 3. As a result, a resistance value corresponding to this movement angle is set between the terminals 6a and 6b and between the terminals 6a and 6c.

In the illustrated embodiment, two protrusions 2a, 2b and 2b, 2d are provided on the heat sink 2 side, and each protrusion is connected to two recesses 3b and 3c provided on the substrate.
The position of the board 3 is determined by fitting the heat dissipating plate 2 into the heat dissipating plate 2.
The protrusions may be provided one by one, or one recess may be formed on the left and right sides of the substrate 3, and each of the recesses and the protrusions may be fitted into each other. Then, this protrusion may be extended as it is and inserted into the groove 7b of the rotary operating body 7.

[Effects of this invention]

As described above, according to the present invention, since the substrate is fixed to the inner surface of the heat sink by concave-convex fitting, the structure and work such as screwing are not required, and the assembly work is simplified. In addition, since the rotation angle of the rotary operating body is regulated by the protrusion supporting the board, there is no need for a mechanism for regulating the rotation angle, simplifying the structure and reducing the external size. become able to. Furthermore, since the protrusions that support the board are protruded from the inner surface of the heat sink,
The heat sink can be easily molded by aluminum die casting, and the molding process is therefore simple.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention.
Figure A is a plan view showing the assembled state of the variable resistor, Figure 1B is its front view, Figure 1C is its side view, Figure 2 is a perspective view showing the assembled state of the variable resistor, and Figure 3 is the case. FIG. 4 is an exploded perspective view of a portion of the internal structure, FIG. 5 is a perspective view of the board attached to the heat sink, and FIG. 6 is a front view of the rotary operating body. be. 1... Frame body, 2... Heat sink, 2a, 2b, 2d
...Protrusion, 2e...Regulation protrusion, 3...Substrate, 3
b, 3c... recess, 4... electrode, 5... resistor,
7... Rotating operation body, 7b... Groove for setting rotation angle, 8a... Slider.

Claims (1)

[Scope of utility model registration request] A variable resistor in which a case is formed by a heat sink and a frame, and a substrate having a resistor and a rotary operating body having a slider that comes into sliding contact with the resistor are housed inside the case. A recess is formed in the circumference of the substrate, and a protrusion is provided on the inner surface of the heat dissipation plate to fit into the recess and position the substrate, and the protrusion is connected to the rotary operating body. A substrate support mechanism for a variable resistor, which is inserted into a formed rotation angle regulating groove.