JPH0414885Y2 - - Google Patents

Description

[Detailed description of the invention] "Field of industrial application" This invention relates to a rotary variable resistor.

"Prior Art" In a rotary variable resistor, it is necessary to minimize the deviation error in the radial direction with respect to the axis when the rotating shaft rotates, and to obtain the set resistance value with high precision and excellent linear characteristics. is desirable.

Particularly when variable resistors are downsized, it is necessary to keep the deviation error in the radial direction from the axis during rotational operation of the rotary shaft sufficiently small.

Proposals have been made in the past to reduce the deviation error in the radial direction of the rotating shaft with respect to the axis.

FIG. 5 shows the configuration of this type of variable resistor that has been proposed in the past. A plate surface 12 facing the open surface of a cylindrical casing 11 made of, for example, synthetic resin and with one side open. A first bearing hole 13 is formed in the first bearing hole 13 .

On the other hand, a rotating shaft 14 is provided, and a rotating body 25 is attached to this rotating shaft 14.

The rotating shaft 14 is made of a synthetic resin material, for example, and is formed into a substantially cylindrical shape as shown in FIG. 6A, and a fitting piece 15 is formed continuously on one end surface of the cylinder.
A pin-shaped portion 16 is formed to protrude from the end surface.

The outer circumferential surface of the fitting piece 15 is composed of a plane part 20 that faces each other in parallel and a circumferential part 21 that faces each other at both ends of the extension of this plane part 20. As shown in FIG. 6B, the rotating body 25 is made of, for example, a synthetic resin material and has a substantially disk shape, and has a fitting hole 21 formed at its center. The inner circumferential surface of the fitting hole 21 is composed of a plane part 22 that faces each other in parallel and a circumferential part 23 that faces each other at both ends of the extension of the plane part 22.

Fitting the fitting piece 15 into the fitting hole 21 and rotating shaft 1
4, the end of the fitting piece 15 is caulked to the periphery of the fitting hole 21 of the rotating body 25, and the rotating body 25 is fixed to the rotating shaft 14.

A sliding body 26 is attached to the rotating body 25,
From this sliding body 26, sliders 27-1, 27-
2 is provided protrudingly. The rotating shaft 14 to which the rotating body 25 is fixed is inserted through the first bearing hole 13, and the rotating shaft 14 and the rotating body 25 are housed in the housing 11. The lid 28 closes the opening of the housing 11 and closes the opening of the housing 1.
1 with adhesive, for example.

A second bearing hole 30 is located at the center of the lid 28.
is formed in the second bearing hole 30, and the rotating shaft 1 is inserted into the second bearing hole 30.
4 pin-shaped portions 16 are inserted.

Further, a resistor 31 and a current collector are formed in a circular shape on the plate surface of the lid 28 on the inside of the housing 11.

A rotating shaft 14 to which a rotating body 25 and a sliding body 26 are fixed is attached and housed in the housing 11, and the opening surface of the housing 11 is closed with a lid body 28. In this state, the sliders 27-1 and 27-2 are in elastic contact with the resistor 31 and current collector 32, respectively. Rotating shaft 14
is rotatably attached to the housing 11, and by rotating the rotating shaft 14, the rotating body 25 rotates, and the sliders 27-1 and 27-2 of the sliding body 26 become resistors, respectively. 31 and the current collector 32 while being in contact with them. A set resistance value corresponding to the rotational position of the rotating shaft 14 is taken out by unillustrated takeout terminals connected to both ends of the resistor 31 and the current collector 32 .

``Problems to be solved with the invention'' In conventionally proposed variable resistors, the rotation axis 1
4 and the rotating body 25 are fixed to each other by fitting between the fitting piece 15 and the fitting hole 21. In positioning by the mutual fitting of the fitting piece 15 and the fitting hole 21,
Due to machining, it is difficult to create a configuration in which the axes are perfectly aligned with each other.

This idea was made in view of the above-mentioned current situation of conventionally proposed variable resistors, and its purpose is to improve the radial axis of the contact position between the resistor and the slider due to the rotation of the rotating shaft. It is an object of the present invention to provide a variable resistor that does not shake, allows highly accurate and stable resistance value setting, and reduces manufacturing costs.

``Structure of the invention'' In this invention, the rotating body mounting portion of the rotating shaft has a knurl formed on the outer periphery of the same diameter as the diameter of the bearing portion of the rotating shaft, and a slot is formed in the rotating body in the axial direction. The rotating body is fitted onto the rotating shaft with the inner peripheral surface of the rotating body facing the knurling formed on the outer periphery of the rotating shaft, and a tightening ring is press-fitted onto the outer periphery of the rotating body, and the rotating body is rotated. The inner peripheral surface of the body is tightened to the knurls and assembled.

Therefore, each component is relatively simple,
Assembling and manufacturing work is easy, reducing manufacturing costs, and the structure is solid, so the contact position between the slider and resistor will not shift in the radial direction of the axis due to the rotation of the rotating shaft. A stable and highly accurate resistance value can be set without any problems.

"Example" Hereinafter, the variable resistor of this invention will be described in detail based on an example using the drawings.

FIG. 1 is a cross-sectional view showing the structure of a first embodiment of this invention, in which a cylindrical casing 11 with one side open is formed of, for example, a synthetic resin material, and the casing has an open side. The case 35 is constructed by closing the surface with a lid 62. First and second bearing holes 38 and 39 are respectively formed in opposing plate surfaces 36 and 37 of the case 35 so as to penetrate through the plate surfaces.

A rotating shaft is rotatably inserted into the case through the first and second bearing holes, and a rotating body to which a sliding body is fixed is attached to the rotating shaft.

As shown in FIG. 7, the rotating shaft 40 is made of metal or synthetic resin and has a cylindrical shape with the same diameter over its entire length. A stop groove 43 is formed on one end of the rotating shaft 40, and a knurl 44 is formed on the outer periphery of the central portion of the rotating shaft 40.

A rotating body with a sliding body fixedly disposed on a rotating shaft is attached.

That is, the retaining ring 45 is engaged with and attached to the retaining groove 43 of the rotating shaft 40. This retaining ring 45
A rotating body having a sliding body fixedly disposed on the rotating shaft 40 is attached to the rotary shaft 40 .

As shown in FIG. 3C, the rotating body 46 is made of, for example, a synthetic resin material and has a substantially cylindrical shape. A radially protruding collar portion 47 is formed on the rotating body 46 at approximately the center thereof in the axial direction. An engagement notch 48 is formed at the peripheral edge of the flange portion 47 . Furthermore, a slot 49 is formed in the rotating body 46 in the axial direction thereof over the entire length.

The sliding body 50 is made of a conductive material, and as shown in FIG. 3B, the periphery of an annular body portion 51 is integrally extended outward, and a sliding body is provided in this extended portion to make elastic contact with the resistor and the current collector. A child is formed along the outer periphery of the main body portion 51. An engaging protrusion 53 is formed to protrude from the plate surface of the main body portion 51 .

Engage the engagement protrusion 53 with the engagement notch 48,
A sliding body 50 is positioned and disposed on the flange 47 of the rotating body 46.

A tightening ring 59 is fitted and fixed onto the sliding body 50 so as to cover the end of the rotating body 46 .
As shown in FIG. 3A, the tightening ring 59 is formed into a substantially annular shape, and a cylindrical portion 56 with a narrowed inner diameter of the annular ring is formed on one side.

The inner diameter of this cylindrical portion 56 is set to be slightly shorter than the outer diameter of the end of the rotating body 46.

Therefore, when the tightening ring 59 is press-fitted onto the end of the rotating body 46 from above the sliding body 50, the interval between the slots 49 of the rotating body 46 is narrowed by the cylindrical portion 56 of the tightening ring 59. For this purpose, the rotating body 4
The inner peripheral surface of the rotating body 6 is tightened to a knurl 44 formed on the outer periphery of the rotating shaft 40, and the rotating body 46 is tightened and fixed to the rotating shaft 40.

A sliding body 50 positioned and arranged on the rotating body 46
is fixed to the rotating body 46 by a tightening ring 59.

With the rotating body 46 and the sliding body 50 fixed to the rotating shaft 40 by the tightening ring 59 in this manner, the end of the rotating shaft 40 opposite to the end to which the retaining ring 45 is attached is inserted from the open surface of the case 35 with the lid 62 removed and inserted into the second bearing hole 39.

A first bearing hole 38 is formed in the lid body 62,
A resistor 54 and a current collector 55 are formed on one surface of the lid 62 concentrically with the first bearing hole 38 . The surface on which the resistor 54 and the current collector 55 are formed is positioned inside the case, and the open surface is closed with the lid 62 to form the case 35 with a sealed structure.

The slider of the sliding body 52 housed in the case 35 is in elastic contact with the resistor 54 and the current collector 55, and the rotation of the rotating shaft 40 causes the rotating body 46 to
rotates, and the slider touches the resistor 54 and the current collector 55.
slide on top.

Therefore, at a predetermined sliding angle, the set resistance value of the variable resistor is taken out between both ends of the resistor 54 and unillustrated lead terminals connected to the current collector 55, respectively.

In the first embodiment, since the rotating shaft 40 is formed to have a wide diameter over its entire length, sufficient strength can be maintained even if the entire shaft is cylindrical. can be fitted to drive the motor.

The configuration shown in FIG. 2 by assigning the same reference numerals to the same parts is the second embodiment of this invention. , an insulating substrate 61 on which a resistor 54 and a current collector 55 are formed is embedded by outsert molding.

A first bearing hole 38 is formed at the center of the bottom plate so as to pass through the bottom plate of the housing 11 and the insulating substrate 61. In the second embodiment, the case 35 is constructed by closing the open surface of the casing 11 in which the insulating substrate 61 is embedded with a lid 62.

The rotating shaft 40 is formed into a cylindrical shape with one end having a narrow diameter, and a retaining ring 43 and a knurl 44 are formed on the rotating shaft 40 as in the first embodiment.

Similarly to the first embodiment, the retaining groove 4 of the rotating shaft 40
A retaining ring 45 is engaged with and attached to the retaining ring 4, and a rotating body 4 having the same shape as the first embodiment is mounted on the retaining ring 45.
6 are fitted and arranged.

In the second embodiment, the sliding body 65 has a shape as shown in FIG. 4, and has a structure in which a tightening ring 59 is integrally formed protruding from the main body 51 of the sliding body 50 used in the first embodiment. , formed by means of drawing.

The sliding body 65 having such a shape is fitted onto the outer periphery of the rotating body 46 from above the rotating body 46 which is fitted and disposed on the rotating shaft 40 . The slot 49 portion of the rotating body 46 is narrowed by the narrow diameter tightening ring 59 of the sliding body 65, and the inner circumferential surface of the rotating body 46 is tightened to the knurl 44 of the rotating shaft 40, so that the inner peripheral surface of the rotating body 46 is tightened against the rotating shaft 40. The rotating body 46 and the sliding body 65 are fixedly assembled.

With the rotating body 46 and the sliding body 65 fixed to the rotating shaft 40 in this manner, the rotating shaft 40 is inserted into the first bearing hole 38 from the open surface of the case 35 . In this state, the retaining ring 45 is located on the end surface of the periphery of the first bearing hole 38 of the housing, and the slider 52 is
It is brought into elastic contact with the resistor 54 and current collector 55 with appropriate elastic force. The open surface of the casing 11 is closed with a lid 62 to give the casing 11 a sealed configuration.

As explained in the first and second embodiments, in this invention, the rotary shaft 40 can be formed into a cylindrical shape with a wide diameter and the same diameter over almost the entire length. Obtained through processing.
The sliding body is fixed to the rotating shaft 40, which has a knurling formed on the outer periphery, and the inner circumferential surface of the rotating body 46 is tightened to the knurling by a tightening ring 59, and both are fixed with their axes aligned. be done.

Therefore, due to the rotation of the rotating body 46, the slider 52
slides on the resistor without wobbling in the radial direction with respect to the resistor and the axis, making it possible to set a stable and accurate resistance value. The manufacturing of each component is easy, and the overall assembly work is also simple, making it possible to provide a variable resistor with stable and highly accurate operating characteristics at low manufacturing costs.

In the embodiment, the case where this invention is applied to a single variable resistor has been described, but this invention can also be applied to, for example, a double variable resistor. In addition, in the embodiment, a slot was formed over the entire length of the rotating body in the axial direction, but a structure in which the slot was formed only at a position corresponding to the tightening ring to be tightened was also described. Things are also possible.

Further, in the first embodiment, it is possible to configure the case with an insulating substrate embedded by outsert molding as in the second embodiment. On the contrary, the second
In the above embodiment, the case may be configured such that the open surface is closed with a lid body as in the first embodiment.

``Effects'' As explained in detail above, according to this invention, the manufacturing of the component parts is relatively easy, the assembly work is simple, and the manufacturing cost can be reduced. It is possible to provide a variable resistor in which the sliding contact position between the child and the resistor does not shift in the radial direction with respect to the axis, and the resistance value can be set stably and with high precision.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a first embodiment of the variable resistor of this invention, FIG. 2 is a sectional view showing the structure of a second embodiment of the variable resistor of this invention, and FIG. 3A , B, and C are perspective views showing the configurations of a tightening ring, a sliding body, and a rotating body, respectively, used in the first embodiment of the variable resistor of this invention, and FIG. 4 is a perspective view of the variable resistor of this invention. A perspective view showing the structure of a sliding body used in the second embodiment, FIG. 5 a cross-sectional view showing the structure of a conventionally proposed variable resistor, and FIGS. 6A and B.
7 is a perspective view showing the shape of a rotating shaft and a rotating body of a conventionally proposed variable resistor, respectively, and FIG. 7 shows a rotating shaft and a retaining ring used in the first embodiment of the variable resistor of this invention. FIG. 3 is a perspective view showing the configuration. DESCRIPTION OF SYMBOLS 11... Housing, 12... Plate surface, 13... First bearing hole, 14... Rotating shaft, 15... Fitting piece, 21
... Fitting hole, 25 ... Rotating body, 26 ... Sliding body,
28... Lid body, 30... Second bearing hole, 35...
Case, 36, 37... Plate surface, 38... First bearing hole, 39... Second bearing hole, 40... Rotating shaft,
43... Retaining ring, 44... Knurl, 45...
Retaining ring, 46... Rotating body, 47... Flange, 48...
...Engagement notch, 49...Slot, 51...Main body, 53...Engagement protrusion, 50...Sliding body, 56...
... Cylindrical part, 59 ... Tightening ring, 54 ... Resistor, 55 ... Current collector, 61 ... Insulating substrate, 62 ...
...Lid body, 65...Sliding body.

Claims (1)

[Scope of Claim for Utility Model Registration] A rotating shaft is rotatably supported by a bearing in a case, a resistor and a current collector are formed concentrically on the center line of the rotating shaft within the case, and the rotating shaft is In a variable resistor in which a rotating body is inserted and attached to the top of the variable resistor, and a sliding body that makes sliding contact with the resistor and current collector is attached to the rotating body, the rotating body mounting portion of the rotating shaft is attached to the rotating body. A knurl is formed in the circumferential direction on the circumferential surface having the same diameter as the diameter of the bearing part of the body, a slot is formed in the axial direction in the rotating body, and a slot is formed on the outer circumferential surface of the rotating body. A variable resistor, characterized in that a tightening ring is press-fitted so that the inner circumferential surface of the rotating body is tightened to the knurling, and the rotating body is fixed to the rotating shaft.