JPH10326703A - Variable resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a variation in the contact pressure of contact parts coming into elastic contact with a resistor by a method wherein the contact parts which come into contact with the resistor are formed in one pair of crescent arm parts which are connected to connection parts so as to be bent to the inside of a bowl-shaped part, ends, one one side, of which are cantilever-supported by the connection parts so as to be extended to the right part and the left part on the outer circumference of the bowl-shaped part and in which free ends are formed. SOLUTION: A flat part 15a which is formed on the outer circumferential side, a bowl- shaped part 15b which is formed in the central part of the flat part 15a so as to protrude downward and a mounting hole 15c are formed at a first plate 15. A second plate 16 in which two connection parts 14a are formed on one side in the outer circumference of the flat part 15a at the first plate 15 and which is formed in such a way that one pair of arm parts 16a whose outer shapes to be catilever-supported by the connection parts 14a have crescent free ends are extended to the right and the left by nearly faced bodies is arranged and installed. At the free ends in tip parts of the pair of arm parts 16a, contact parts 16b which are formed so as to protrude to be semicircular are faced with the connection parts so as to sandwich the bowl-shaped parts 15b, they are installed side by side in the radial direction connecting the center of an opening, and their side faces are in a state that they come into contact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a slider of a variable resistor, for example, a slider for adjusting a resistance value by sliding on a resistor.

[0002]

2. Description of the Related Art A conventional variable resistor will be described with reference to FIGS. First, as shown in FIG. 6 which is a sectional view of a main part, and FIG. A substantially horseshoe-shaped resistor 3 centered on the center hole 1a is provided on the surface of the substrate 1.
Are formed by printing or the like. A pair of external electrodes 3a, 3a made of silver or the like are arranged on both ends of the resistor 3 from the side surface to the back surface of the substrate 1. Further, the slider 4 is formed by bending a single conductive thin plate such as a phosphor bronze plate having elasticity by 180 ° so as to face each other, and a driver plate 5 is formed at an upper portion and an arm portion 6 is formed at a lower portion. The driver plate 5 and the arm 6 are bent and integrated at a connecting portion 7 formed at an end of the driver plate 5.

[0003] The driver plate 5 has a substantially circular outer shape, a substantially dish-shaped projection 5a protruding downward at the center, and the substrate 1 at the bottom center of the projection 5a.
And a mounting hole 5b having substantially the same dimensions as the center hole 1a. Further, the driver plate 5 includes
A flat flat portion 5c is formed outside the upper portion of the protrusion 5a, and a cross-shaped driver groove 5d is formed in a part of the flat portion 5c and a side wall forming the protrusion 5a. An opening is formed in the driver groove 5d by punching, and an arm 6 described later can be viewed from the opening.

The arm 6 which is bent downward facing the driver plate 5 has a substantially circular ring shape as shown in the bottom view of the slider 4 shown in FIG. The inner opening 6a is formed to be larger than the outer diameter of the protrusion 5a of the driver plate 5.
The connecting portion 7 is bent so that the protrusion 5a of the driver plate 5 is located in the opening 6a. The arm portion 6 is formed in a ring shape by base portions 6b, 6b extending left and right from the connecting portion 7, and a slider piece 6c supported at both ends by the base portions 6b, 6b. . Further, a cutting line 6d for dividing the slider piece 6c into two in an arc shape is formed by punching or the like.

At the center of the slider piece 6c on the side facing the connecting portion 7, there are provided contact portions 6e, 6e divided into two by the cutting line 6d. 5a is formed in the same direction as that of 5a. Since the contact portions 6e are separated from each other, they can move freely and independently. A terminal 8 made of an iron plate or the like is provided on the lower surface side of the substrate 1, and the terminal 8 has a support shaft 8a having a hollow hole formed by drawing or the like.
Thus, the substrate 1 and the driver plate 5 of the slider 4 are caulked. The arm 6 is located below the flat portion 5c of the slider 4, and the two contact portions 6e and 6e formed on the arm 6 are located on the surface of the resistor 3 to be a conventional variable. A resistor is configured.

[0006]

However, the contact portions 6e, 6e of the slider 4 of the conventional variable resistor as described above.
Are supported at both ends by the left and right bases 6b, 6b of the arm 6, so that the contact portion 6 which resiliently contacts the resistor 3 against the variation of the bending angle at which the arm 6 is bent.
The contact pressures of e and 6e tended to change significantly. For this reason, it is necessary to perform frequent maintenance of processing equipment such as a mold and to perform complicated management so that the bending angle of the arm 6 does not vary.

Further, when the cutting line 6d is formed by punching, if burrs or the like are generated in the cutting portion or dust or the like enters the cutting line 6d, the two contact portions 6e, 6e are cut. May not be able to move independently, and the performance of the variable resistor may be reduced. As a solution to this, there is a method of forming a gap in the cutting line 6d. However, this method has a problem that the outer diameter of the arm portion 6 is increased due to the gap, and therefore the variable resistor is increased.

[0008]

As a first means for solving the above problems, a variable resistor according to the present invention comprises a resistor, a substrate on which the resistor is formed, and a surface of the resistor. A sliding member that slides, and a support shaft that rotatably supports the slider on the substrate, wherein the slider has a bowl-shaped part protruding toward the substrate and an upper outer periphery of the bowl-shaped part. With a connecting portion
A plate, connected to the connecting portion of the first plate and bent toward the bowl-shaped portion, one end of the connecting portion being cantilevered and extending to the left and right of the outer periphery of the bowl-shaped portion to form a free end at the other end. The second plate is provided with a pair of crescent-shaped arms, and a pair of contacts in contact with the pair of resistors are provided on the pair of arms.

[0009] A second aspect for solving the above-mentioned problem is as follows.
The pair of contact portions of the variable resistor according to the present invention is formed at a free end of the arm portion and is provided to face a connecting portion with the bowl-shaped portion interposed therebetween. Are arranged side by side in the radial direction.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A variable resistor according to an embodiment of the present invention will be described with reference to FIGS. First, as shown in the cross-sectional view of the main part of FIG. 1 and the plan view of FIG.
1 is provided, and a center hole 11a is formed in a substantially central portion of the substrate 11.
Are formed to penetrate. On the surface of the substrate 11, a substantially horseshoe-shaped resistor 13 having the center hole 11a as a center is formed by printing or the like.

On one end face of the resistor 13, a pair of external electrodes 13a, 13a made of silver or the like are arranged from the front surface to the back surface of the substrate 11 so as to be connected to the resistor 13. . Further, with the center hole 11a of the substrate 11 as a fulcrum, the surface of the resistor 13 is rotationally slid,
In addition, a slider 14 made of one conductive thin plate having elasticity, such as phosphor bronze, is bent from the two connecting portions 14a. As shown in the developed view of FIG. 3, the slider 14 has a first plate 15 having a substantially circular outer shape and a flat portion 15a formed on the outer peripheral side and a central portion of the flat portion 15a. A bowl-shaped portion 15b projecting downward by processing or the like, and a mounting hole 15c is formed at the center of the bottom of the bowl-shaped portion 15b.

The flat portion 15 including the bowl-shaped portion 15b
A cross-shaped driver groove 15d composed of a concave portion having a peripheral side wall is formed in a by drawing or the like. The driver groove 15d can be adjusted by either a plus driver or a minus driver.
The depth dimension of the driver groove 15d is formed to be about half the depth of the bowl-shaped portion 15b as shown in FIG.

The flat portion 15 of the first plate 15
A pair of arm portions 1 having two free ends each having a crescent-shaped outer shape and having two connecting portions 14a, 14a formed on one side of the outer periphery of the outer portion a.
A second plate 16 is provided, which is formed by extending the left and right sides 6a and 16a substantially in opposition to each other. A substantially circular opening 16c is formed inside the pair of arms 16a, 16a formed opposite to each other. At the free ends at the tips of the pair of arms 16a, 16a, contact portions 16b, 16b projecting in a semicircular shape face the connecting portion 14a with the bowl-shaped portion 15b interposed therebetween, and the opening is formed. 1
6c are arranged side by side in the radial direction connecting the centers of 6c, and their side surfaces are in contact with each other. Further, the contact portions 16b, 16b
In the unfolded state shown in FIG. 3, the projecting direction is formed so as to project upward in the opposite direction to the bowl-shaped portion 15b of the first plate 15.

Further, the slider 14 bends the second plate 16 below the first plate 15 from the bending line AA shown in FIG. 3 as shown in FIG. The opening 16c is located on the protruding bowl-like portion 15b. Then, the projecting direction of the pair of contact portions 16b, 16b is on the lower side in the same direction as the bowl-shaped portion 15b of the first plate 15. Further, as shown in the bottom view of FIG. 5, the second plate 16 after bending the slider 14 is
A pair of arm portions 16a, 16a having free ends which are cantilevered by the connecting portions 14a, 14a and extend right and left around the outer periphery of the bowl-shaped portion 15b are formed.
Contact portions 16b, 16b are arranged at the free ends of a, 16a in the radial direction connecting the center of the bowl-shaped portion 15b. The contact portions 16b, 16b are disposed such that their side surfaces are in contact with each other.

The folded slider 14 is shown in FIG.
As shown in the figure, the second plate 16 arm portions 16a, 16a are located below the flat portion 15a of the first plate 15,
The two contact portions 16 b are located on the surface of the resistor 13 on the substrate 11. In addition, the first
As shown in FIG. 5, the outer diameter of the plate 15 is formed to be slightly larger than the outer diameter formed by the arms 16a of the second plate 16. Therefore, at the time of mounting or adjusting the variable resistor of the present invention, the suction portion of the mounting machine or the driver for adjustment does not hit the arm portion 16a of the second plate 16 to deform the arm portion 16a.

As shown in FIG. 1, a terminal 18 made of metal or the like is provided on the lower surface of the substrate 11. The terminal 18 has a support shaft 18a having a hollow hole formed by drawing or the like, and a tongue piece 18b that bends an end of the terminal 18 to close the hollow hole of the support shaft 18a. The tongue piece 18b prevents the flux or the like at the time of soldering from entering the slider 14 on the upper side of the substrate 11. The center hole 11 of the substrate 11
A ring-shaped washer 19 and a mounting hole 15c of the first plate 15 of the slider 14 are inserted into the tip of the support shaft 18a inserted into the washer 19 projecting from the surface of the substrate 11. Then, the tip of the support shaft 18a is caulked to hold the slider 14 rotatably on the support shaft 18, and the two are electrically connected to each other to constitute the variable resistor of the present invention.

When assembling the variable resistor according to the present invention, the terminal 18 is positioned and mounted on an assembling jig (not shown), and the center hole 11a of the substrate 11 is inserted into the support shaft 18a of the terminal 18. Next, the washer 19 is inserted into the tip of the support shaft 18a protruding from the center hole 11a of the substrate 11, and the mounting hole 15c of the first plate 15 of the slider 14 is inserted from above the washer 19 and placed. When the tip of the support shaft 18a of the terminal 18 is swaged with a swaging jig (not shown), the substrate 11, the slider 14, the terminal 18, and the washer 19 are integrated, and the variable resistor according to the present invention is integrated. Is assembled.

After the variable resistor of the present invention is mounted on a printed circuit board (not shown) or the like, a driver (not shown) is inserted into a driver groove 15d in order to rotate and adjust the slider 14.
When inserting, the driver groove 15
d, the adjustment load is applied to the bowl-shaped portion 15.
Since the bottom surface of b can serve as a stopper to be received, the adjustment load is not applied to the contact portions 16b of the second plate 16, and the contact pressure of the contact portions 16b does not vary. A flat portion 15a is formed on the first plate 15 of the slider 14, and a flat portion 15a including the bowl-shaped portion 15b is formed by a cross-shaped recess having a side wall around it by drawing or the like. When the variable resistor of the present invention is mounted on a printed circuit board (not shown) using a mounting machine (not shown), the mounting machine removes the flat portion 15a because the driver groove 15d is formed. When sucked, the bowl-shaped portion 15b and the driver groove 15
Since the inside of d is in a sealed state, the variable resistor of the present invention can be securely mounted without air from entering from outside. Further, in the embodiment of the variable resistor of the present invention as described above, the respective contact portions 16b, 16b of the second plate 16 of the slider 14 have been described with the side surfaces thereof in contact with each other. Each contact portion 16b, 16
b may be separated from each other and a gap is formed between them.

[0019]

The slider of the variable resistor according to the present invention comprises: a first plate having a bowl-shaped portion protruding toward the substrate side and a connecting portion on the outer periphery of the upper portion of the bowl-shaped portion; A pair of crescent-shaped arms that are connected to a connecting portion, bent toward the bowl-shaped portion, one end of which is cantilevered at the connecting portion, and extend to the left and right of the outer periphery of the bowl-shaped portion to form free ends. A pair of contact portions, each of which is in contact with the resistor, is provided on the pair of arm portions, the pair of arm portions being cantilevered with respect to a variation in a bending angle to be bent from the connection portion. Because of the support, the contact pressure of the contact portion resiliently contacting the resistor can be made smaller than the contact pressure of the double-supported contact portion of the conventional variable resistor.

A pair of contact portions are formed at the free end of the arm portion, are provided opposite to the connecting portion with the bowl-shaped portion interposed therebetween, and are arranged in a radial direction connecting the centers of the bowl-shaped portions. With this arrangement, the distances from the connecting portion to the respective contact portions at the free ends of the arm portions can be made substantially the same. Therefore, the contact pressure of each of the contact portions can be made substantially the same, and the contact between the contact portion and the resistor can be
Can be stabilized.

Further, since the side surfaces of the pair of contact portions are in contact with each other, there is no need to form a gap between the pair of contact portions, and the outer diameter of the slider can be reduced.
Therefore, the size of the variable resistor can be reduced. Further, even if the side surfaces contact each other and the contact portion is caught by a burr or dust, the pair of arm portions cantileverly support one end of the connecting portion and can move independently of each other. Therefore, a pair of contact portions provided at the free ends of the arm portions can also move independently of each other. Therefore, even if burrs or dust enter between the respective contact portions, a stable contact pressure without variation can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a variable resistor according to the present invention.

FIG. 2 is a plan view of a variable resistor according to the present invention.

FIG. 3 is a developed view of a slider of the variable resistor according to the present invention.

FIG. 4 is a side view of the variable resistor according to the present invention after the slider is bent.

FIG. 5 is a bottom view of the variable resistor according to the present invention after the slider is bent.

FIG. 6 is a sectional view of a main part of a conventional variable resistor.

FIG. 7 is a plan view of a conventional variable resistor.

FIG. 8 is a bottom view of a slider of a conventional variable resistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Substrate 11a Center hole 13 Resistor 14 Slider 14a Connecting part 15 First plate 15a Flat part 15b Bow-shaped part 15d Driver groove 16 Second plate 16a Arm part 16b Contact part 18 Terminal 18a Support shaft 18b tongue piece 19 Washer

Claims (3)

[Claims] 1. A resistor, a substrate on which the resistor is formed, a slider that slides on the surface of the resistor, and a support shaft that rotatably supports the slider on the substrate. A first plate having a bowl-shaped part protruding toward the substrate side and a connection part on the upper periphery of the bowl-shaped part; and a bowl-shaped part connected to a connection part of the first plate. A second plate provided with a pair of crescent-shaped arms each of which is bent to the side, one end of which is cantilevered at the connecting portion, extends to the left and right of the outer periphery of the bowl-shaped portion, and has a free end at the other end. And a pair of arms provided with a pair of contacts in contact with the pair of resistors, respectively. 2. The pair of contact portions are formed at a free end of the arm portion, are provided opposite to a connecting portion with the bowl-shaped portion interposed therebetween, and extend in a radial direction connecting a center of the bowl-shaped portion. 2. The variable resistor according to claim 1, wherein the variable resistors are arranged side by side. 3. The variable resistor according to claim 1, wherein said pair of contact portions are in contact with each other at their side portions.