JP3705517B2 - Potentiometer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary potentiometer that is attached to the outer surface of a housing, has a structure in which a rotating shaft led out to the outer surface is inserted and rotated by the rotating shaft.
[0002]
[Prior art]
The structure of a conventional potentiometer of this type is shown in FIGS. FIG. 5 shows a state in which the potentiometer is attached to the housing, and FIGS. 6 to 8 show the configuration of the potentiometer 11 in an exploded manner.
As shown in FIG. 6, the resin case 12 has a metal bearing 13 inserted and attached to the bottom surface thereof, and the resistance substrate 15 in which the hole 14 is formed is positioned in the hole 14. The case 12 is accommodated and fixed. The case 12 is box-shaped, and the upper surface side is open.
[0003]
The resistor substrate 15 has a required pattern formed on an insulating substrate. In this example, a pair of arc-shaped resistors 16 and 17 are formed to face each other with the hole 14 interposed therebetween, and an arc-shaped current collector is formed on the outside thereof. The bodies 18 and 19 are formed. Each of the resistors 16 and 17 and the current collectors 18 and 19 are provided with extension conductors 20 as shown in the drawing, and these extension conductors 20 are connected to terminal electrodes 21 arranged on one side of the resistance substrate 15, respectively. Has been.
[0004]
Lead wires 22 are soldered and connected to the terminal electrodes 21, and the other ends of these lead wires 22 are led out of the case 12. The case 12 has a pair of mounting portions 23 protruding in an ear shape, and mounting holes 25 formed by embedding metal rings 24 in the mounting portions 23 are formed.
As shown in FIG. 7, the slider 26 that is in sliding contact with the resistance substrate 15 held by the case 12 is attached to the rotating body 27. The rotating body 27 made of a resin material has a disk shape having a mounting hole 28 in the center, and a pair of sliders 26 are mounted on one plate surface thereof. In this example, the slider 26 is a so-called wire brush in which a plurality of wires made of a noble metal such as a gold alloy are attached to a bus bar. A pair of wire brushes are attached to a leaf spring 29, and the base of the leaf spring 29 is a rotating body. 27 is attached by being caulked.
[0005]
The rotating body 27 is attached and fixed to a rotating shaft via a drive spring 31 made of a leaf spring material. As shown in FIG. 8, the drive spring 31 has a base portion 33 in which an oval shaft hole 32 is formed, and a plurality of leg portions 34 that extend radially from the base portion 33, and each leg portion 34. Is bent with respect to the base 33 and is raised obliquely. In this example, three leg portions 34 are provided to form a tripod shape, and a claw 35 projecting in three directions is formed at the tip of each leg portion 34. As shown in the drawing, a plurality of kerfs 36 for press-fitting are formed in the inner edge of the shaft hole 32.
[0006]
On the plate surface opposite to the plate surface to which the slider 26 of the rotating body 27 is attached, a U-shaped peripheral wall portion 37 to which each leg portion 34 of the drive spring 31 is locked as shown in FIG. Are projected at equiangular intervals.
Next, attachment of the potentiometer 11 having the above configuration to the housing will be described. In FIG. 5, reference numeral 41 denotes a housing that houses the detected movable part, and reference numeral 42 denotes a rotating shaft that works in conjunction with the movable part. The rotating shaft 42 is led out to the outer surface 44 of the housing 41 through a hole 43 formed in the housing 41. In the mounting structure as shown in FIG. 5, for example, in an automobile, a rotating shaft that rotates in conjunction with opening and closing of the throttle valve is led out of the housing, and the rotating shaft depends on the opening of the throttle valve. This is used when a potentiometer is installed to obtain a high output.
[0007]
First, the case assembly 45 shown in FIG. 6 is attached to the casing 41 with its bottom face being in contact with the outer surface 44 of the casing 41. Although not shown in the drawing, the attachment is performed by screwing using a pair of attachment holes 25. At this time, the rotating shaft 42 is positioned at the axial center position in the bearing 13.
Next, the rotor assembly 46 shown in FIG. 7 is inserted into the cylindrical portion 13a whose mounting hole 28 protrudes from the bottom surface of the case 12 of the bearing 13, and the plate surface on which the peripheral wall portion 37 is provided is the outside. Thus, it is rotatably mounted around the cylindrical portion 13a of the bearing 13.
[0008]
Then, the drive spring 31 is attached between the rotating shaft 42 and the rotating body 27 and the attachment is completed. At this time, the rotation shaft 42 is press-fitted into the shaft hole 32 of the drive spring 31, and thereby the base 33 of the drive spring 31 is locked to the rotation shaft 42. On the other hand, the tips of the leg portions 34 are press-fitted into the peripheral wall portions 37 of the rotating body 27, and the claws 35 are deformed and pressed to be engaged with the peripheral wall portions 37. In this state, the rotor assembly 46 is urged toward the resistance board 15 by the drive spring 31, that is, each slider 26 is brought into elastic contact with the resistance board 15.
[0009]
In the potentiometer 11 mounted as described above, the rotation of the rotating shaft 42 is transmitted to the rotor assembly 46 by the drive spring 31 to rotate the rotor assembly 46, and each slider 26 is associated with the corresponding resistor. By making sliding contact with the electrical bodies, ie, 16, 18, 17 and 19, the resistance value is variable, and an output corresponding to the rotation angle is obtained. In addition, by having this drive spring 31, it is possible to absorb the vertical movement and undulation rotation of the rotating shaft 42, that is, the rattling of the rotating shaft 42 does not act on the rotating body 27.
[0010]
[Problems to be solved by the invention]
By the way, in this kind of potentiometer 11 mounted as described above, the case assembly 45, the rotor assembly 46 and the drive spring 31 are generally not integrated at the time of shipment, that is, shipped as an assembly part (kit part). The user has assembled and used them. Accordingly, the case assembly 45, the rotor assembly 46, and the drive spring 31 are packaged in three parts at the time of shipment, which increases the packaging cost. In addition, the user side requires time and effort, and the installation cost is expensive.
[0011]
Furthermore, since the case 12 is open, dust and foreign matter can easily enter the case 12, which may cause unstable electrical contact between the slider 26 and the resistance substrate 15. It was.
An object of the present invention is to provide a potentiometer that eliminates these conventional problems, has a low packaging cost and a low installation cost, and can prevent dust and foreign matter from entering the case.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, a resistance board is arranged around the bearing on the bottom surface to which the bearing is attached, the upper surface side is opened, one end is connected to the resistance board, and the other end is led out of the case. A plurality of lead wires and a disc shape having a mounting hole in the center, and the mounting hole is inserted into a cylindrical portion protruding upward from the bottom surface of the bearing so as to be rotatable around the cylindrical portion. A rotating body that is attached to one plate surface of the rotating body and that is in sliding contact with the resistance substrate, a leaf spring material, a base portion having an axial hole, and a plurality of radially extending portions from the base portion A rotation shaft led to the outer surface of the casing, the case being attached to the outer surface of the housing Is inserted into the shaft hole and pressed into the shaft hole, thereby engaging the rotating shaft. A potentiometer having a structure in which the rotating body is urged toward the resistance substrate and rotated by the driven spring, and the other plate surface of the rotating body faces the outside, and has a hole having a slightly smaller diameter than the rotating body. The cover is attached to the case, the rotating body is confined in the case by the cover, and each leg portion of the drive spring is locked to the rotating body.
[0013]
According to a second aspect of the present invention, in the first aspect of the present invention, an alignment portion for pressing and aligning a plurality of lead wires in the case is provided integrally with the cover.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the part corresponding to FIGS. 5-8, and the description is abbreviate | omitted.
FIG. 1 shows an embodiment of the present invention. In this example, the potentiometer 51 is configured such that a case assembly 52 and a rotor assembly 53 are integrated by a cover 54, and the drive spring 31 is attached to the rotor assembly 53.
[0015]
In this example, the case assembly 52 is configured as shown in FIG. That is, in this example, the potentiometer 51 is formed in a triple form, and the resistor substrate 15 has another set of patterns including a switch body 55 and a current collector 56 in addition to the resistors 16 and 17 and the current collectors 18 and 19. Is formed. The region 55a in the switch body 55 is a conductor region, and the region 55b is an insulator region.
[0016]
In the case 12, a holding portion 58 for positioning and holding the lead wire 22 protrudes from the bottom surface of the case 12 in the lead wire lead-out portion 57 where the lead wire 22 connected to each terminal electrode 21 of the resistance substrate 15 is located. The lead wires 22 are formed and received and held in grooves 59 arranged in the holding portion 58. These lead wires 22 are led out of the case 12 through notches 61 arranged on the side wall 12a of the case 12 so as to correspond to the lead wires 22.
[0017]
In this example, the pair of attachment holes 25 for attaching the case 12 to the housing by screws are substantially oval. Further, a pair of pins 62 are formed integrally with the case 12 so as to sandwich the bearing 13 on the upper end surface of the side wall 12a.
The rotor assembly 53 is configured as shown in FIG. 3, and three sliders 26 are attached to the plate surface of the rotating body 27 facing the resistance substrate 15. On the other hand, a groove 63 is formed on the entire periphery of the rotating body 27 on the periphery of the plate surface on which the peripheral wall portion 37 projects.
[0018]
The cover 54 has a shape as shown in FIG. 4 and is formed, for example, by pressing a metal plate. A wide-diameter hole 64 is provided at the center of the plate surface, and a pair of pin holes 65 are provided with the hole 64 interposed therebetween. The diameter of the hole 64 is slightly smaller than the outer diameter of the rotating body 27 described above.
The outer shape of the cover 54 is similar to the shape formed by the side wall 12a of the case 12, and the portion corresponding to the lead wire lead-out portion 57 of the case 12 is bent into a U shape as shown in the figure. Thus, an alignment portion 66 is formed. In addition, small projections 67 are respectively provided at both ends of the portion of the alignment portion 66 corresponding to the middle portion of the U-shape. On the other hand, a claw 68 is bent at the end opposite to the alignment portion 66.
[0019]
Next, assembly of the case assembly 52, the rotor assembly 53, the cover 54, and the drive spring 31 will be described with reference to FIG.
The rotor assembly 53 is disposed in the case 12 by inserting the cylindrical portion 13 a of the bearing 13 into the mounting hole 28 of the rotating body 27. Then, the cover 54 is attached to the case 12. At this time, the pair of pins 62 of the case 12 are respectively passed through the pin holes 65 of the cover 54, and the claws 68 of the cover 54 are engaged with the grooves 69 formed on the outer surface of the side wall 12 a of the case 12 to be positioned. Is done. The cover 54 is fixed to the case 12 by caulking the pins 62.
[0020]
On the other hand, the alignment portion 66 of the cover 54 is press-fitted into the lead wire lead-out portion 57 of the case 12, and the small protrusion 67 is locked to the inner surface of the side wall 12a. The lead wires 22 are pressed down and aligned by the aligning portion 66 to prevent the lead wires 22 from being lifted. Further, the notches 61 for leading out the lead wires 22 arranged in the side wall 12 a are covered by the bent legs of the U-shaped alignment portion 66.
[0021]
The outer periphery of the rotating body 27 is confined in the case 12 by being pressed by the cover 54. The peripheral wall portion 37 of the rotating body 27 is located in the hole 64 of the cover 54, and the drive spring 31 is attached by press-fitting and locking the claw 35 at the tip of each leg portion 34 of the drive spring 31 to the peripheral wall portion 37. Thus, the potentiometer 51 is completed. The lead wire lead-out portion 57 may be filled with an adhesive to bond the lead wire 22, and the alignment portion 66 may be bonded and fixed to the case 12.
[0022]
The potentiometer 51 configured as described above is attached to the casing 41 from which the rotation shaft 42 is derived. The potentiometer 51 is disposed on the outer surface 44 of the casing 41 and the rotation shaft 42 through which the bearing 13 is inserted. First, the drive spring 31 is press-fitted and attached, and then the case 12 is fixed to the housing 41 by screwing. In addition, since it is comprised so that the plate | board surface in which the surrounding wall part 37 of the rotary body 27 is formed may face the exterior from the hole 64 of the cover 54, the drive spring 31 can be attached or detached freely, for example.
[0023]
【The invention's effect】
As described above, according to the present invention, the rotating shaft is inserted through the outer surface of this type of casing, which has been conventionally divided into parts and shipped as a kit component, and a driving spring is engaged with the rotating shaft. Since the potentiometer configured to be stopped is formed by integrating the constituent parts, the packaging cost at the time of shipment is lower than the conventional one. In addition, the installation is simplified on the user side, and the installation cost is low.
[0024]
Further, since the case 12 is covered with the cover 54, dust and foreign matter are less likely to enter the case 12, so that a good and stable electrical contact state between the slider 26 and the resistance substrate 15 can be obtained. it can.
In addition, in the invention of claim 2, since the alignment portion 66 is provided in the cover 12, by attaching the cover 12, the floating of the lead wire 22 can be easily prevented.
[Brief description of the drawings]
FIG. 1A is a plan view showing an embodiment of the present invention, and B is a cross-sectional view showing a state in which A is attached to a casing.
2A is a plan view showing the configuration of the case assembly in FIG. 1, and B is a cross-sectional view thereof. FIG.
3A is a plan view showing the configuration of the rotor assembly in FIG. 1, B is a cross-sectional view thereof, and C is a bottom view thereof. FIG.
4 is a perspective view of the cover in FIG. 1. FIG.
FIG. 5 is a cross-sectional view showing a state in which a conventional potentiometer is attached to a housing.
6A is a plan view showing the configuration of the case assembly in FIG. 5, and B is a cross-sectional view thereof. FIG.
7A is a plan view showing the configuration of the rotor assembly in FIG. 5, B is a cross-sectional view thereof, and C is a bottom view thereof. FIG.
8A is a plan view of the drive spring in FIG. 5, and B is a cross-sectional view thereof. FIG.

Claims (2)

A case where a resistance board is arranged around the bearing on the bottom surface where the bearing is attached, and the top surface side is open,
A plurality of lead wires having one end connected to the resistor substrate and the other end led out of the case;
A disk having a mounting hole in the center, the mounting hole is inserted through a cylindrical part protruding above the bottom surface of the bearing, and a rotating body that is rotatable around the cylindrical part;
A slider attached to one of the plate surfaces of the rotating body and in sliding contact with the resistance substrate;
A drive spring made of a leaf spring material, having a base portion having an axial hole, and a plurality of leg portions extending radially from the base portion, the tip ends of the leg portions being locked to the other plate surface of the rotating body And
The case is attached to the outer surface of the housing, and the rotating shaft led out to the outer surface is inserted into the shaft hole and press-fitted into the shaft hole, so that the rotation is performed by the driving spring locked to the rotating shaft. A potentiometer having a structure in which a body is urged toward the resistance substrate and rotated.
A cover having a hole slightly smaller in diameter than the rotating body, the other plate surface of the rotating body facing outside, is attached to the case, and the rotating body is confined in the case by the cover, and the driving is performed on the rotating body. A potentiometer characterized in that each leg of the spring is locked. The potentiometer according to claim 1, wherein
A potentiometer, wherein an alignment portion for pressing and aligning the plurality of lead wires in the case is provided integrally with the cover.

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