JP3172656B2 - Variable resistor and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable resistor capable of changing a resistance value by a slider sliding on an arc-shaped resistor and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, among variable resistors which change the resistance value by rotating a slider on an arc-shaped resistor, those whose resistance can be adjusted from both front and back sides are usually those on the front side. A driver slot is provided on the adjustment knob, and a driver slot on the back side is formed at a portion where the center axis of the resistance adjustment knob is on the back side of the substrate, so that the resistance can be adjusted from both sides.

Further, a variable resistor which is small in size and cannot form a driver slot in the central axis on the back side of the substrate is inserted into a metal plate having a driver slot formed from the back side of the substrate and engaged with a slider. Enables resistance adjustment.

[0004]

In the case of the above-mentioned conventional technology, there is a margin for forming a driver slot in the center axis of the adjustment knob on the back surface side of the substrate in response to the demand for miniaturization of electronic parts which is increasing more and more in recent years. There is a problem that it is gone.

[0005] Further, in the case where a metal plate for a driver slot is engaged with the slider from the back side of the substrate, there is a problem that the number of parts is increased and the cost and the number of assembling steps are increased. Also, a cross-shaped through hole is formed on the adjustment knob,
Although it is possible to insert the driver from the back, it is possible to insert the driver into the through-hole and adjust the rotation of the driver slot. Moreover, since the driver is usually thicker toward the base end side, if the driver is inserted into the small through hole, the driver will be inserted to the position where it fits tightly in the slot, and it will be necessary to remove the driver after adjustment There is a disadvantage that it takes time. Furthermore, if the play after the driver is inserted into the slot is too large, it is difficult to make fine adjustments, and it is difficult to set this slot space.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and enables accurate resistance adjustment from both front and back sides with a simple structure even in a small variable resistor, and has a mechanical strength. It is an object of the present invention to provide a variable resistor having a high resistance.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a variable resistor capable of adjusting the resistance from both the front and back surfaces of a substrate on which a resistor is formed, wherein the variable resistor is integrally formed with a resistance adjustment knob provided on the front surface of the substrate. Make a notch in the part of the drive shaft
The forked part is formed to a predetermined depth to provide a bifurcated part,
The center part of the forked part is hollowed out halfway in the axial direction.
The cutout is formed, and the cutout is formed
The forked portion is provided on the substrate with the cut portion interposed therebetween.
Fan-shaped fusion zone formed on both sides of the
Variable resistor. Then, by the cutting portions, a driver slot for inserting the driver is formed, the bottom portion of the notch portion abutting the driver tip
Part, and the rotating shaft is rotatable with respect to the bearing part.
The variable resistor is attached and has an electrode formed at a terminal connection portion at one end of the substrate, and a U-shaped attachment portion of a terminal is fitted and fixed to the electrode.

Further, according to the present invention , a notch is formed to a predetermined depth in a portion of the rotating shaft integrated with the resistance adjusting knob provided on the front surface of the substrate and inserted into the back surface of the substrate to provide a bottom portion.
The forked part is provided in the middle of the forked part.
In the central portion to form a hollow portion hollowed out in the axial direction, the shaft above times and inserted into a bearing portion fixed to said substrate, said
Cut the bifurcated part with the cutout part into the notch part
Melt and deform on both sides across the
Spread out and pivotally attach the rotation axis to the bearing part of the substrate.
This is a method for manufacturing a variable resistor to be attached. And the above cut
A driver slot having a contact portion at the tip of the driver is formed by the insertion portion, and a U-shaped mounting portion provided on a terminal is fitted to an electrode formed at a terminal connection portion at one end of the substrate. This is a method for manufacturing a variable resistor for fixing a terminal.

[0009]

The variable resistor according to the present invention is easy to assemble, allows the insertion and rotation operation of the tip of the driver, and adjusts the resistance from the back side even if it is a small variable resistor having a small rotating shaft. It is easy to do, and the adjustment knob has a high mounting strength.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. In the variable resistor of this embodiment, as shown in FIGS. 2 to 7, a resistor 2 of a carbon-based film or a metal glaze film is formed in a U-shape on a surface 1a of an insulating substrate 1 made of ceramics or the like. The slider 3 is mounted above the slider. The contact point 4 formed on a part of the slider 3 is in sliding contact with the resistor 2, and is in sliding contact with the outer peripheral portion of the metallic cylindrical bearing portion 5 fitted to the substrate 1, and is rotatable. Is provided. The slider 3 is provided in the storage portion 7 of the resistance adjusting knob 6 provided on the front surface 1a side of the substrate 1, and the engagement piece 3a of the slider 3 is engaged with the engagement recess 7 of the storage portion 7.
a, and rotatably provided integrally with the resistance adjusting knob 6.

The resistance adjusting knob 6 is made of synthetic resin such as nylon, and has a cross-shaped driver slot 6a formed on the front side and a slider on the back side as shown in FIGS. A storage section 7 such as 3 is formed. In the center of the back surface, a columnar rotating shaft 13 that rotates around the bearing portion 5 is formed. At the tip of the rotating shaft 13, cut portions having a gap width of 1.8 mm and facing each other are formed. A forked portion 14 which is a forked divided portion by 14d is provided. The bifurcated portion 14 is formed in a cylindrical shape extending from the rotation shaft 13, and has a cutout 14.
d, and the side wall portions 14 facing in parallel with each other
b. In order to facilitate melting deformation in the assembling process, the inside of the forked portion 14c is formed as a cut-out portion 14c from the tip of the forked portion 14 to a predetermined depth of the side wall portion 14b.

As shown in FIGS. 2 to 7, both ends of the resistor 2 are connected to electrodes 8a formed on the terminal connection portions 8 of the substrate 1 and provided by firing glass silver paste or the like. I have. Each electrode 8 is connected to a mounting portion 10 of a U-shaped terminal 9 projecting from the substrate 1 and soldered with a solder 8b. Further, the bearing portion 5 in which the slider 3 is rotatably slidably in contact with the outer peripheral portion is formed integrally with the mounting portion 12 of the intermediate terminal 11 formed in the central portion of the back surface 1b of the substrate 1. The intermediate terminal 11 is connected to the mounting portion 12
, And extends downward 1 b below the back surface of the substrate 1.

Each of the terminals 9 and 11 is provided with a rib 17 for increasing the strength, and a sliding end is provided at one end of the mounting portion 12 as shown in FIGS. 3, 5, and 6. Child 3
A stopper 18 is provided for restricting the rotation range of the motor. The stopper 18 protrudes from the back surface 1b of the substrate 1 to the front surface 1a side and penetrates through the through hole 1c formed in the substrate 1, so that the slider 3 is brought into contact with a fixed rotation angle. The intermediate terminal 9 formed integrally therewith is prevented from rotating when the resistance adjusting knob 6 rotates.

Further, as shown in FIGS. 1, 4 to 7, the rotating shaft 13 of the resistance adjusting knob 6 is fitted to the bearing 5 so as to be rotatable from the front surface 1 a side of the substrate 1. . Then, as shown in FIG. 1, the tip of the rotating shaft 13 protruding toward the back surface 1b of the substrate 1, when assembling this variable resistor,
It is fitted into the bearing part 5 and protrudes from the mounting part 12 of the middle terminal 11. Thereafter, the tip of the forked portion 14 is heated and melted by a jig, and as shown in FIGS. 4, 5, and 7, the pieces of the forked portion 14 are separated from each other at the cutout 14d. To form a pair of fan-shaped fused portions 15 on the back surface of the mounting portion 12 so that the resistance adjusting knob 6 does not come off the substrate 1. The fan-shaped melting portion 15 is widely melt-deformed to such an extent that the tip portion contacts the surface of the mounting portion 12 of the middle terminal 11. Here, a cutout portion 14c is formed in the forked portion 14 to the vicinity of the rear surface of the substrate, and a cutout portion 14d is formed toward the knob 6 side to form the forked portion 14. The side wall 14b of the cutout 14d is a plane in which planes parallel to each other face each other.

The bottom portion 14a of the forked portion 14
And the side wall portion 14b and the inner surface 5a of the bearing portion 5 form a contact portion where the end surface and the side surface of the driver tip contact with each other, and form a slot 16 for adjusting the driver on the back surface side of the variable resistor. . Here, the bottom surface portion 14a and the side wall portion 14b, which are part of the rotating shaft 13, rotate, but the bearing portion 5 does not rotate. The attachment of the resistance adjusting knob 6 and the melting of the forked portion 14 are performed by the terminals 9,
11 may be before or after soldering.

In the variable resistor of this embodiment, the resistance adjusting driver slot on the back side is not formed inside the rotating shaft 13, but the rotating shaft itself is divided into two parts. Therefore, the center axis can be made as thick as the required width of the driver slot, and a slot for adjusting the driver can be formed on the back side even with a very small variable resistor with a narrow rotating shaft. It is possible to adjust the resistance from the back side.

Further, since the cut-out portion 14c is formed in the split portion 14, the split portion 14 is easily bent and spread at the time of melting, so that the fan-shaped fused portion 15 can be reliably formed. In particular, a two-part fan-shaped melting part 15 is engaged with the attachment 12 on the back surface of the substrate, and it is surely manually operated to hold the member rotatably.

Further, in this embodiment, the resistance adjusting knob 6
Is attached to the substrate 1 by melting the tip of the rotating shaft 13, so that the lower end edge of the resistance adjusting knob 6 contacts the substrate 1 without any gap, the rotation is smooth, and the dustproof effect is high.

The tip of the rotating shaft according to the present invention melts to form a stopper as described above.
As shown in FIG. 3, at the time of forming the resistance adjusting knob 6, a collar-shaped engaging portion 20 is integrally formed at the tip of the bifurcated portion 14,
When the bearing is inserted into the bearing of the variable resistor, the bifurcated portion 14 is elastically deformed and inserted into the bearing. After the insertion, the locking portion 20 engages with the edge of the bearing to prevent the variable resistor from coming off. May be performed.

Thus, the step of melting the tip of the rotating shaft to prevent the resistance adjusting knob 6 from coming off can be omitted, the number of man-hours can be reduced, and the shaft can be simply inserted into the bearing. This makes it easy to automate insertion.

Further, the bearing portion of the variable resistor according to the present invention comprises:
In addition to the one integrally formed from the mounting portion of the intermediate terminal as in the above-described embodiment, a metal plate forming the slider may be further deepened to form the bearing portion. Further, the slot on the back side of the variable resistor according to the present invention may be a slot in which the rotation axis is divided and the entire width thereof is a slot, and the divided portion may be divided into three or four. Needless to say. Further, the shape of the terminal and the shape and size of the driver slot can be arbitrarily determined, and are not limited to the above-described embodiment.

[0022]

According to the variable resistor of the present invention, the slot used for adjusting the resistance on the back side is formed by dividing the tip of a rotating shaft rotatably provided inside the bearing. Therefore, the width of the slot can be made as large as the width of the rotating shaft, and the slot for driver adjustment can be formed on the back side even with the thin rotating shaft of a small variable resistor.
Further, a contact portion of the driver center portion is formed in the driver slot, thereby making the rotation operation of the driver easy and reliable with little backlash. Further, since the grounding of the terminal is performed by fitting the U-shaped mounting portion formed on the terminal, the assembling is easy even with a small variable resistor, and a reliable connection is made.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a back surface side of an embodiment of a variable resistor according to the present invention.

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

FIG. 3 is a front view of the variable resistor according to the embodiment.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a bottom view of this embodiment.

FIG. 6 is a plan view of the variable resistor according to this embodiment in a state where a resistance adjusting knob is removed.

FIG. 7 is a sectional view taken along line BB of FIG. 2;

FIG. 8 is a plan view of the resistance adjusting knob of this embodiment.

FIG. 9 is a front view of the resistance adjusting knob of this embodiment.

FIG. 10 is a bottom view of the resistance adjusting knob of this embodiment.

FIG. 11 is a sectional view taken along the line CC of FIG. 8;

FIG. 12 is a sectional view taken along line DD of FIG. 8;

FIG. 13 is a front view of another embodiment of the resistance adjusting knob of the variable resistor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Resistor 5 Bearing part 6 Resistance adjustment knob 13 Rotating shaft 14a Bottom part 14d Cut part 15 Fused part 16 Slot

Continuation of the front page (56) References JP-A-61-131513 (JP, A) JP-A-62-142805 (JP, A) Japanese Utility Model Application No. Sho 61-179703 (JP, U) Japanese Utility Model Application Utility Model No. Sho 53-96685 (JP , U) Japanese Utility Model Showa 53-96684 (JP, U)

Claims (2)

(57) [Claims] 1. A variable resistor capable of adjusting resistance from both front and back surfaces of a substrate on which a resistor is formed, wherein the variable resistor is provided on a back surface side of a rotating shaft integrated with a resistance adjusting knob provided on the front surface side of the substrate.
A notch is formed to a predetermined depth in the inserted part
The forked part is provided
A hollow part is formed by hollowing out the center part in the axial direction.
The bifurcated part with the notched part is the notch
On both sides of the bearing provided on the substrate with the
And a fan-shaped fused portion is formed, a driver slot is formed by the cutout for inserting a driver, and a bottom portion of the cutout serves as a contact portion of the driver tip.
The rotation shaft is rotatably attached to the bearing.
Vignetting, variable resistor electrodes are formed in the terminal connecting portion of the one end of the substrate, the U-shaped mounting portion of the terminal is fitted fixed to the electrode. 2. A notch is formed in a portion of a rotating shaft integrated with a resistance adjusting knob provided on the front surface side of the substrate and inserted into the rear surface side of the substrate.
The forked part with the bottom part is formed to a predetermined depth
Along with the center part of the bifurcated part,
A hollow portion is formed by punching out in the direction, and the rotating shaft is inserted into a bearing portion fixed to the substrate, and the hollow portion is formed.
The formed bifurcated part on both sides of the cut part
Melt and deform, spread the forked part into a fan shape, and rotate
The shaft is rotatably attached to the bearing part of the substrate.
The abutment at the tip of the driver is provided by the notch
A method for manufacturing a variable resistor, comprising: forming a driver slot obtained as described above, and fitting a U-shaped mounting portion provided on the terminal to an electrode formed at a terminal connection portion at one end of the substrate to fix the terminal.