JP2002151310A - Potentiometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a potentiometer in which a contact member is fixed surely to a rotor. SOLUTION: If a contact member 20 generates plays in a rotor 3, a potentiometer may produce hysteresis during normal rotation and reverse rotation of a rotary shaft 7, thereby causing highly accurate angle measurement to fail. Therefore, the rotor 3 is comprised of a flat-plate first rotor half part 30 and a second rotor half part 40, and a base-side end 21 of the contact member 20 is pinched by two rotor half parts 30 and 40, and then the base-side end 21 and rotor half parts 30 and 40 are press-fitted to each other, so that they come into contact with each other. By taking such measures, frictional resistance is produced between the base-side end 21 and rotor half parts 30 and 40, and the frictional resistance is utilized, to more surely fix the contact member 20 to the rotor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a potentiometer incorporated in an electric device or the like and used for position angle control.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field are disclosed in Japanese Patent Application Laid-Open Nos. Hei 10-293005 and Hei 11-5160.
No. 6 publication. In the potentiometer described in this publication, a rotor fixed to a shaft is rotatably arranged in a housing space of a case. When the shaft is turned by a predetermined angle, a sliding contact member such as a brush provided on the rotor moves on the resistor,
Accordingly, the resistance value of the resistor is changed, and the rotation angle of the shaft is measured based on the voltage value extracted from the resistor to the outside. In this type of potentiometer, it is common practice to fix the sliding contact member to the rotor by using an adhesive or fusion caulking.

[0003]

However, the above-mentioned conventional potentiometer has the following problems. That is, the sliding contact member that rotates together with the rotor while sliding on the resistor needs to be securely fixed to the rotor. This is because if the sliding contact member has looseness, hysteresis occurs between the forward rotation and the reverse rotation of the shaft, and highly accurate angle measurement cannot be performed. In order to prevent such a situation from occurring, it is necessary to securely fix the sliding contact member to the rotor. However, the conventional fixing uses only bonding and fusion, so that external impact and The sliding contact member is likely to rattle due to an external temperature change or the like. Also, it goes without saying that the reliable fixing of the sliding contact member by the bonding operation or the fusion operation largely depends on the skill of the operator.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a potentiometer in which a contact member is securely fixed to a rotor.

[0005]

SUMMARY OF THE INVENTION A potentiometer according to the present invention is a potentiometer in which a resistor and a contact member having a tip portion sliding on the resistor are disposed in a case, and one end of the potentiometer is projected from the case. A rotating shaft, a rotor fixed to the other end of the rotating shaft, to which a contact member is attached, and a substrate opposed to the rotor in the case and provided with a resistor, wherein the rotor has a plate-like first shape. The contact member is formed of a rotor half and a second rotor half, and the contact member is provided with a flat base end, and the flat portion of the first rotor half and the flat portion of the second rotor half facing each other. Thus, the first and second rotor halves are pressed against the base end of the contact member.

In this potentiometer, the rotating shaft, the rotor, and the contact member are fixed integrally, and as a result, the rotating shaft is rotated in a predetermined direction so that the tip of the contact member slides on the resistor of the substrate. You will move while moving. At this time, if the contact member is loosely attached to the rotor, hysteresis occurs between the forward rotation and the reverse rotation of the rotating shaft, and there is a possibility that highly accurate angle measurement cannot be performed. In view of this, the rotor is formed of two members, that is, a plate-shaped first rotor half and a second rotor half, and the flat base end of the contact member is sandwiched between the two rotor halves. The ends and the rotor halves are crimped in contact with each other. By such a measure, a frictional resistance is generated between the base end and the rotor half,
Utilizing this frictional resistance, the fixing of the contact member to the rotor is further ensured.

The projection provided on the flat portion of the first rotor half is inserted into a through hole provided at the base end of the contact member, and is inserted into the flat portion of the second rotor half. It is preferable to fit into the provided recess. In the case of adopting such a configuration, the first rotor half and the second rotor half can be assembled to each other by the concave and convex fitting, so that the rotor can be assembled reliably. Further, when the base end of the contact member is sandwiched between the two rotor halves, the protrusion of the rotor half is inserted into the through hole of the base end, so that the contact member can be securely assembled to the rotor. In addition, the assembling workability is improved.

The first rotor half and the second rotor half have the same shape, and extend from the base end of the contact member into a slit extending radially from the peripheral surface of the second rotor half. It is preferable to insert a rising portion. In this way, by forming the first rotor half and the second rotor half in the same shape, parts can be shared and the manufacturing cost can be reduced. Moreover, since the rising portions of the contact members are inserted into the slits provided in the rotor half, the positioning of the contact members with respect to the rotor is assured, which is advantageous in terms of assembly workability.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a potentiometer according to the present invention will be described below in detail with reference to the drawings.

The potentiometer 1 shown in FIG. 1 has a case 2 made of plastic or metal and having a diameter of about 2 cm. In this case 2, a disk-shaped rotor 3 made of an electrically insulating resin and a substrate 5 are housed side by side so as to face each other, and a contact member 20 made of an elastic metal is fixed to the rotor 3. ing. As shown in FIG. 2, the contact member 20 has a flat ring-shaped base end 21 having a shaft insertion port 24 at the center, and a pair of inner brushes extending from the base end 21 and branched into two branches. It has a piece 22 and an outer brush piece 23, and each brush piece 22, 23 is formed integrally with the contact member 20 in a state of being electrically connected to each other.

Further, the rotor 3 is fixed to the other end side of a rotary shaft 7 for projecting one end from the case 2 to function as a rotary knob. On the front side of the substrate 5, a metal first resistor 6a with which the tip of the inner brush piece 22 is in sliding contact is formed at the center portion, and outside the resistor 6a, A second resistor 6b made of metal with which the tip of the outer brush piece 23 makes sliding contact is formed in a C-shape. The first resistor 6a is electrically connected to a terminal piece 9 protruding in the connector portion 8 of the case 2.

Therefore, when the rotary shaft 7 is turned by a predetermined angle in a state where a predetermined voltage is applied to both ends of the second resistor 6b, the tip portions of the brush pieces 22, 23 become the respective resistors 6b.
a, 6b, and changes the resistance value of the resistor 6b based on the movement of the brush piece 23. Then, the rotation angle of the rotary shaft 7 is measured based on a voltage value taken out from the terminal piece 9 connected to the first resistor 6a.

The above-mentioned disk-shaped rotor 3 and substrate 5
Are arranged in a housing space 10 formed in the case 2, and in this housing space 10, the rotor 3 and the substrate 5
Is arranged side by side so as to be separated in the direction of the axis L of the rotating shaft 7. The case 2 is formed with a circular opening 11 that allows the housing space 10 to communicate with the outside. The rotor 3 and the substrate 5 are loaded through the opening 11 in assembling the potentiometer 1. Such an opening 1
The use of 1 improves the workability of assembling the potentiometer 1 in the direction of the axis L. After the incorporation of each component into the housing space 10 is completed, rubber,
A lid 12 made of plastic or metal is fitted, and the lid 12 is fixed to the case 2 by bonding or caulking.

An annular convex portion 17 protruding in the direction of the axis L is formed on the peripheral portion of the lid portion 12. When the assembly of the lid 12 is completed, the projection 17
Is pressed in the direction of the axis L by the tip of
The outer peripheral portion on the front surface side of the substrate 5 is pressed so as to be in close contact with the seating surface 2 a of the case 2. As described above, due to the fact that the lid 12 has the convex portion 17, the outer peripheral portion on the front surface side of the substrate 5 is pressed against the case 2 during the assembly work, so that the lid 12 and the substrate 5 are in close contact with each other, and The close contact between the substrate 5 and the case 2 is made easy and reliable, and the assembling of the potentiometer 1 in the direction of the axis L becomes easy and reliable.

In particular, it is preferable that the lid 12 itself is made of an elastically deformable member such as rubber or plastic.
In this case, since the convex portion 17 of the lid portion 12 is pressed against the back surface of the substrate 5 while being elastically deformed, the adhesion between the substrate 5 and the case 2 and the adhesion between the diaphragm 12 and the substrate 5 can be improved. it can.

Here, the rotor 3 fixed to the rotating shaft 7 is composed of two members made of electrically insulating plastic. Specifically, the rotor 3 includes a disk-shaped first rotor half 30 and a second rotor half 40 having a flat surface, and a circular flat surface of the two rotor halves 30 and 40. One rotor 3 is formed by facing the parts 30a and 40a so as to overlap each other. In this rotor 3, parts are shared in order to reduce the manufacturing cost, and the first rotor half 30 and the second rotor half 40 have the same shape.

As shown in FIG. 2, the first rotor half 30
Is a first shaft insertion opening 31 provided at the center, an annular first meshing portion 32 protruding from the outer periphery of the shaft insertion opening 31 in the direction of the axis L, and an axis L extending from the flat portion 30a.
It has a first convex portion 33 formed in the direction, and a first concave portion 34 formed in the direction of the axis L from the plane portion 30a. Similarly, the second rotor half 40 includes a second shaft insertion port 41 provided at the center and the shaft insertion port 4.
An annular second meshing portion 42 protruding from the outer periphery of the first member toward the first meshing portion 32 in the direction of the axis L, and a second portion formed in the direction of the axis L from the flat portion 40a toward the first concave portion. It has two convex portions 43 and a second concave portion 44 formed in the direction of the axis L from the flat portion 40a toward the first convex portion 33.

Further, in order to share parts, the rotor half 3
Since it is necessary to use the same thing as the first half and the rotor half 40, in the rotor half 30, the protrusion 33 and the recess 34 have the same diameter, and the first meshing part 32 has the same diameter. , And those having an uneven shape that is equally divided are employed. As the rotor half 40, the one obtained by turning the rotor half 30 upside down is used, and the protrusion 33 and the recess 44 are fitted, and the protrusion 43 and the recess 34 are
The protrusion 33 and the recess 34 are line-symmetric with respect to a straight line passing through the diameter of the plane portion 30a of the rotor half 30 in order to achieve the engagement between the engagement portion 32 and the engagement portion 32 with the engagement portion 42. Are formed at symmetrical positions with the relationship of, and the unevenness of the engagement portion 32 is formed so as to appear symmetrically at the line-symmetrical relationship.

Further, the flat base end 21 of the contact member 20 is sandwiched by the cooperation of the rotor half 30 and the rotor half 40, and the first and second rotor half 3
0,40 is pressed. Specifically, the protrusions 33 and the recesses 4
4, the fitting of the convex portion 43 and the concave portion 34, and the meshing portion 3.
2 while engaging the engagement portion 2 with the engagement portion 42,
Plane portion 30a of second rotor half 30 and second rotor half 4
The base end portion 21 of the contact member 20 is sandwiched between the zero plane portion 40a and pressed.

By such a measure, a frictional resistance is generated between the base end 21 and the plane portions 30a, 40a of the rotor halves 30, 40, and the frictional resistance is utilized by utilizing the frictional resistance.
The contact member 20 is more firmly fixed with respect to. As described above, it is desired that the rotor 3 and the contact member 20 be firmly fixed. If the contact member 20 has a backlash with respect to the rotor 3, hysteresis occurs between the forward rotation and the reverse rotation of the rotating shaft 7. However, there is a possibility that highly accurate angle measurement cannot be performed.

Further, the base end 21 is provided with a through hole 26 for inserting the first projection 33 of the first rotor half 30. Therefore, the through-hole 26 is formed in the first projection 33.
Is inserted, the first convex portion 33 and the second concave portion 44 are inserted.
Are fitted to each other, so that the contact member 20 can be securely assembled to the rotor 3 easily, and the assembling workability is improved. Further, the diameter of the shaft insertion port 24 of the base end portion 21 is formed to be larger than the diameter of the first and second meshing portions 32 and 42. Thus, even when the meshing portions 32 and 42 are employed, the base end 21 of the contact member 20 is securely connected to the flat portion 30a of the first rotor half 30 and the flat portion 40a of the second rotor half 40. And press-bonded.

Further, the first and second rotor halves 30, 4
0 has slits 36 and 46 extending radially from the peripheral surface. The slit 46 is provided with the contact member 20.
A rising portion 24 extending from the base end portion 21 and connected to each of the brush pieces 22 and 23 is inserted. By doing so, it is possible to arrange the brush pieces 22 and 23 on the resistor 6a and 6b side, and at the same time, to ensure the positioning of the contact member 20 with respect to the rotor 3.

The plastic rotor half 3
After the components 20, 30, and 40 are fitted to the rotary shaft 7, a metal washer 47 is fitted to the tip of the rotary shaft 7 in order to integrate the metal contact members 20 and 40 with the metal contact member 20. Push the tip of the end outward with a caulking jig. As a result, the two rotor halves 3
0, 40 and the contact member 20 are the steps 7a of the rotary shaft 7.
And fixed. In addition, the metal washer 47 includes:
An outwardly projecting claw portion 47a is provided. The claw portion 47a is provided in the receiving hole 4 provided in the second rotor half 40.
8 is inserted at the time of crimping, and the rotation of the rotor 3 with respect to the rotating shaft 7 is prevented.

The potentiometer of the present invention is not limited to the embodiment described above. For example, the first rotor half 30 and the second rotor half 40 are the same part, but may have different configurations. Alternatively, the rotor halves 30, 40 may be fixed to each other with an adhesive in a state where the rotor halves 30, 40 are pressed against the base end 21 of the contact member 20.

[0025]

Since the potentiometer according to the present invention is constructed as described above, the following effects can be obtained.
That is, a resistor and a contact member whose tip portion slides on the resistor, in a potentiometer arranged in the case, a rotating shaft having one end protruding from the case, and fixed to the other end of the rotating shaft, A rotor to which a contact member is attached, and a substrate which is opposed to the rotor in the case and on which a resistor is provided are provided, and the rotor is formed by a first half and a second half of a flat plate. The contact member is provided with a flat base end, and the flat end of the first rotor half and the flat end of the second rotor half sandwich the base end of the contact member. By pressing the first and second rotor halves against the portion, the contact member can be securely fixed to the rotor.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a potentiometer according to the present invention.

FIG. 2 is an exploded perspective view in which main parts of the potentiometer of FIG. 1 are enlarged.

[Explanation of symbols]

1: Potentiometer, 2: Case, 3: Rotor, 5 ...
Substrate, 6a, 6b: resistor, 7: rotating shaft, 20 ...
Contact member, 21: base end portion, 24: rising portion, 26: through hole, 30: first rotor half, 30a: flat portion of first rotor half, 33: convex portion, 40: second Rotor half, 4
0a: flat portion of the second half of the rotor, 44: concave portion, 46:
Slit, L ... axis.

Claims (3)

[Claims] 1. A potentiometer in which a resistor and a contact member whose tip end slides on the resistor are disposed in a case, wherein: a rotating shaft having one end protruding from the case; A rotor fixed to the end and to which the contact member is attached; and a substrate facing the rotor in the case and provided with the resistor, wherein the rotor is a flat first rotor half. And a second rotor half, wherein the contact member has a flat base end, and a flat portion of the first rotor half and a flat portion of the second rotor half facing each other. Wherein the base end of the contact member is sandwiched, and the first and second rotor halves are pressed against the base end. 2. A projection provided on the flat portion of the first rotor half, wherein the projection is inserted into a through hole provided at the base end of the contact member, and the second rotor half is inserted. 2. A potentiometer according to claim 1, wherein said potentiometer is fitted in a recess provided in said flat portion of said portion. 3. The first rotor half and the second rotor half have the same shape, and the base of the contact member is provided in a slit extending radially from a peripheral surface of the second rotor half. 3. A potentiometer according to claim 1, wherein a rising portion extending from the end is inserted.