JPH10335118A - Variable resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of poor contact by a method wherein the spring part, having a free end, of a lead out terminal is brought into contact with the second terminal, and the terminal part of the lead out terminal is arranged on the same surface side as the first terminal. SOLUTION: The tip of free end of the spring part 8a of a lead-out terminal 8 is elastically connected to the recessed part 4a of the second terminal 4, and the lead-out terminal 8 and the second terminal 4 are brought into the state wherein they are conductive. Also, the first terminal, which is provided on an insulated substrate 1, is arranged on the same surface as the lower side face 7a where the terminal part 8b of the lead-out terminal 8 is positioned. Also, a nearly box-shaped case 7, consisting of molded synthetic resin, etc., is provided with an aperture 7d, having a stepped part 7c extending to the upper side face 7b from the lower side face 7a, an engaging part 7f provided in front, a recessed part 7h provided outside a backside 7g, and a pair of protruding part 7j provided inside the backside 7g. Also, the lead-out terminal 8 is formed by the elastic metal material such as a metal plate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable resistor which is used in small electronic devices such as video cameras, car stereos, telephones and the like, and is suitable for surface mounting on a printed circuit board.

[0002]

2. Description of the Related Art As shown in FIGS. 6 to 8, a variable resistor used in a conventional small electronic device has a horseshoe-shaped resistor 32 and a First terminals 33 made of silver or the like provided at both ends are formed. Further, a slider 35 is provided on a rotating body 34 formed by punching and bending a metal plate, and the rotating body 34 is a plate-shaped second terminal 36 disposed on the back surface of the insulating substrate 31. Are rotatably mounted on the surface of the insulating substrate 31 by eyelets 36a provided on the
During the rotation of, the slider 35 slides on the resistor 32. An operating section 37 having a driver groove 37a is attached to the rotating body 34, and the rotating body 34 is rotated via the operating section 37.

An opening 38c having a locking projection 38b is provided on a front surface 38a of a case 38 made of synthetic resin.
In addition, as shown in FIG. 7 in particular, a lead-out terminal 39 is buried in the case 38, and a connection portion 39a having both ends buried is provided so as to be exposed at the bottom of the opening 38c. The terminal portion 39 b is disposed so as to be exposed on the lower side surface of the case 38. Then, the insulating substrate 31, the rotating body 34,
The semi-finished product is formed by assembling the second terminal 36 and the operation unit 37, and the semi-finished insulating substrate 31 is housed in the opening 38c of the case 38 from the front surface 38a side of the case 38, and the insulating substrate 31 is formed by the protrusion 38b. Hook 31 and press fit,
The semi-finished product is attached to the case 38, and the second terminal 36 located on the back surface is brought into contact with the connection portion 39a of the lead-out terminal 39. That is, in this semi-finished product, the insulating substrate 31 is inclined, and the upper end of the insulating substrate 31 is opened.
c, the upper end of the insulating substrate 31 is locked to the protrusion 38b, and then, in this state, the lower end of the insulating substrate 31 is rotated about the upper end as a fulcrum, and is inserted into the opening 38c. The press-in end is press-fitted so as to be incorporated into the case 38.

[0004] The variable resistor assembled in this manner includes a first terminal 33 and a terminal portion 39 of a lead-out terminal 39.
b is located on the same surface as the lower side surface of the case 38. Then, such a variable resistor is mounted on the printed circuit board 40 by surface mounting. First, cream solder (not shown) is applied to a conductor (not shown) provided on the printed circuit board 40. Thereafter, the lower side surface of the case 38 is placed on the printed circuit board 40, and this is passed through a heating furnace to solder the first terminal 33 and the lead-out terminal 39 to the conductor.

[0005]

The conventional variable resistor is:
Since both ends of the connection portion 39a of the lead-out terminal 39 attached to the case 38 are embedded, the resilience of the connection portion 39a is small, so that the mounting position of the insulating substrate 31 varies.
That is, as shown in FIG. 7, there is a problem that the second terminal 36 does not come into contact with the connection portion 39a due to variation in a direction away from the connection portion 39a, and a contact failure occurs. Also,
An opening 38c is provided in the front surface 38a of the case 38, and the insulating substrate 31 is attached from the front surface 38a side.
The upper end of the insulating substrate 31 is inserted into the opening 38c, and the upper end of the insulating substrate 31 is engaged with the protrusion 38b. Then, in this state, the lower end of the insulating substrate 31 is turned around the upper end as a fulcrum. It is necessary to perform an operation of pushing and press-fitting into the opening 38c, which causes a problem that the assemblability is low and the cost is high. In addition, the insulating substrate 31 attached in this manner is subjected to a force that tends to come off in the direction of the front surface 38a, and the second terminal 36 and the connecting portion 39a are insufficiently or separated from each other, resulting in poor contact. There is a problem. Further, the lower part of the insulating substrate 31 attached from the front surface 38a side of the case 38 is weakly supported, and there is a problem that the semi-finished product comes off the case 38 due to an impact after assembly.

[0006]

As a first means for solving the above problems, an insulating substrate made of an insulating material is provided.
A resistor provided on the surface of the insulating substrate, a first terminal provided on the insulating substrate in a state of being electrically connected to the resistor, rotatably attached to the insulating substrate, and slidingly contacting the resistor. A rotating body provided with a slider, a second terminal electrically connected to the slider, and provided on the back surface of the insulating substrate, and a case combined with the insulating substrate; And a spring portion having a free end of the lead terminal is elastically contacted with the second terminal, and the terminal portion of the lead terminal is on the same surface as the first terminal. The configuration was arranged. Further, as a second solution, an insulating substrate made of an insulating material, a resistor provided on a surface of the insulating substrate, a first terminal provided on the insulating substrate in a state of being electrically connected to the resistor, A rotary member rotatably attached to the insulating substrate and provided with a slider that slides on the resistor, and a second terminal that is electrically connected to the slider and is exposed on the back surface of the insulating substrate; And a case combined with the insulating substrate, having a case having an opening on a side surface, and a lead terminal attached to the case, wherein the case is provided with the insulating substrate from the side opening side,
The second terminal is brought into elastic contact with the lead-out terminal, and the terminal portion of the lead-out terminal and the first terminal are arranged on the same surface side.

As a third solution, the case is formed of an insulating material such as a synthetic resin and the lead-out terminal is formed of a metal material. As a fourth solution, the case has a substantially box shape, an opening is provided in a side surface of the case, and the insulating substrate is attached to the case from an opening side of the side surface. The portion is configured to elastically contact the second terminal. Further, as a fifth solution, the lead terminal has a terminal portion located on the opening end side of the case, and a spring portion is disposed to be inclined inside the opening. As a sixth solution, a concave portion is provided in the second terminal, and a spring portion of the lead-out terminal is elastically contacted with the concave portion. Further, as a seventh solution, the second terminal is formed by a plate-like terminal having a cylindrical eyelet, and the rotating body is attached at the eyelet, and a spring of the lead-out terminal is attached to the eyelet. The part was elastically contacted.

[0008]

FIG. 1 shows a variable resistor according to the present invention.
FIG. 1 is a front view of a variable resistor according to the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG.
FIG. 3 is a front view of a cover according to the variable resistor of the present invention, and FIG.
Is a rear view of the cover, and FIG. 5 is a cross-sectional view taken along line BB of FIG. As shown in FIGS. 1 to 5, the variable resistor according to the present invention includes a flat insulating substrate 1 made of an insulating material such as a synthetic resin or a ceramic. A resistor 2 formed of carbon or the like on the surface of a substrate 1 and a pair of first terminals 3 formed of silver or the like or formed of a plate-shaped metal plate in a state where both ends of the resistor 2 are electrically connected. Have.

A second terminal 4 made of a plate-like metal plate is provided.
Has a circular concave portion 4a and an eyelet portion 4b provided at the center of the concave portion 4a, and the second terminal 4 is mounted by being embedded in the insulating substrate 1, and in the mounted state, The recess 4a and the vicinity of the recess 4a are exposed on the back surface of the insulating substrate 1, and the eyelets 4b protrude into the recess 1a of the insulating substrate 1. Also, the metal plate,
Rotating body 5 formed by punching, drawing, and bending
Is a bottomed cylindrical portion 5c having a driver groove 5a in the side wall and a hole 5b in the bottom wall, and a slider 6 formed by bending from the front wall to the back surface and integrally with the rotating body 5. With
The rotating body 5 is formed by inserting the cylindrical portion 5c into the concave portion 1a of the insulating substrate 1, press-fitting the eyelet 4b of the second terminal 4 into the hole 5b, and caulking the tip of the eyelet 4b. 5 is attached. And when the rotating body 5 is attached, the rotating body 5 can rotate around the eyelet part 4b, and
During rotation, the slider 6 slides on the resistor 2.

A substantially box-shaped case 7 made of synthetic resin or the like has an opening 7d having a step 7c extending from a lower side surface 7a to an upper side surface 7b, and a locking portion 7f provided on a front surface 7e. And a recess 7h provided outside the back surface 7g.
And a pair of projections 7j provided inside the back surface 7g. The lead-out terminal 8 made of a metal material having a spring property such as a metal plate includes a spring portion 8a having one free end,
And a U-shaped terminal portion 8b provided at the other end.
As shown in FIG. 2, the lead-out terminal 8 is attached to the U-shaped terminal portion 8 b by sandwiching the back surface 7 g of the case 7. The concave portion 7 h and the pair of protrusions 7 j are connected to the lead-out terminal 8. It supports both sides and serves as a guide when mounting.
When the lead-out terminal 8 is attached to the case 7,
The terminal 8b is located on the end side of the opening 7d, and the spring 8
a has an opening 7d whose free end side is based on the terminal 8b.
It is in an inclined state inside.

Then, a semi-finished product is formed by combining the insulating substrate 1 having the second terminal 4 and the rotating body 5. In order to incorporate this semi-finished product into the case 7 having the lead-out terminal 8,
First, the rotating body 5 is positioned on the front surface 7e side, and the insulating substrate 1
Is positioned on the side of the opening 7 d of the case 7 and the step 7
c. Next, the insulating substrate 1 is inserted into the step portion 7c, and the insulating substrate 1 is pushed in while being sandwiched between the locking portion 7f and the step portion 7c, so that the upper end of the insulating substrate 1 is placed on the upper side surface 7b of the case 7. Upon collision, product assembly is completed. Then, when assembled, as shown in FIG. 2, the tip of the free end of the spring portion 8 a of the lead-out terminal 8 is
a, the lead-out terminal 8 and the second terminal 4 are electrically connected to each other, and the first terminal 3 provided on the insulating substrate 1.
Is a lower side surface 7a where the terminal portion 8b of the lead-out terminal 8 is located.
It is in the state of being arranged on the same surface as. As can be seen from FIG. 2, when the insulating substrate 1 is inserted into the case 7, the spring portion 8a of the lead-out terminal 8 moves along the back surface of the insulating substrate 1 in the direction of arrow D. The tip of the portion 8a resiliently contacts the second terminal 4 and the spring portion 8 inclined upward.
a prevents the semi-finished product from falling off toward the opening 7d of the lower side surface 7a. Also, when inserting a semi-finished product, a force in the direction held by the case 7 is applied to the terminal portion 8a,
The terminal portion 8a does not fall off the case 7.

The variable resistor assembled in this manner is mounted on a printed circuit board 9 by surface mounting. First, a cream solder (not shown) is attached to a conductor (not shown) provided on the printed circuit board 9. (Not shown), the lower side surface 7a of the case 7 is placed on a printed circuit board 9, and this is passed through a heating furnace to solder the first terminal 3 and the lead-out terminal 8 to a conductor. It is.

The case 7 may be made of a metal body, and the opening 7d has been described as being provided on the lower side surface 7a. However, the upper side surface 7b or the right or left side surface has been described. Further, the spring portion 8a may be provided so as to penetrate from the lower side to the upper side surface.
b may be elastically contacted by being inserted into the hole b.
May be embedded and attached to the case 8 by insert molding or the like.

[0014]

According to the variable resistor of the present invention, the free end of the spring portion 8a of the lead-out terminal 8 provided on the case 7 is elastically contacted with the second terminal 4 exposed on the back surface of the insulating substrate 1. In addition, even if the mounting position of the insulating substrate 1 varies, the lead-out terminal 8 reliably contacts the second terminal 4 and a variable resistor free from poor contact can be provided. Further, since the opening 7d is provided in the side surface 7a of the case 7 and the insulating substrate 1 is mounted from the opening 7d side of the side surface 7a, the mounting of the insulating substrate 1 becomes simpler than in the conventional case, and the assembling property is good and the cost is low. Can provide things. When the insulating substrate 1 is attached through the opening 7d of the side surface 7a, the position of the insulating substrate 1 in the front direction can be reliably regulated, and the elastic contact between the second terminal 4 and the lead-out terminal 8 can be reliably achieved.
No poor contact occurs.

Further, the case 7 is formed of an insulating material, and
By forming the lead-out terminal 8 from a metal material, the lead-out terminal 8 can be formed.
Can be embedded in the case 7, and the assemblability can be further improved. Also, an opening 7d in the side surface 7a of the case 7
Since the insulating substrate 1 is inserted and attached from the side and the spring portion 8a of the lead-out terminal 8 is elastically contacted with the second terminal 4, the spring portion 8a can be elastically contacted with the second terminal 4 with the insertion operation, and the workability is good. Inexpensive things can be provided. Further, since the spring portion 8a of the lead-out terminal 8 is disposed obliquely inside the opening 7d, it can be easily inserted into the opening 7d of the insulating substrate 1, has good assemblability, and has a good quality. Dropout prevention can be performed. Further, a concave portion 4a is provided in the second terminal 4, and the concave portion 4a is formed.
Since the spring portion 8a of the lead-out terminal 8 is resiliently contacted with a, the semi-finished insulating substrate 1 can be more securely prevented from coming off, and the concave portion 4a and the spring portion 8a It is elastically engaged and locked, and its assemblability is improved. Furthermore, since the spring portion 8a of the lead-out terminal 8 is elastically contacted with the cylindrical eyelet portion 4b, the insulating substrate 1 as a semi-finished product can be more reliably prevented from coming off, and the insulating substrate 1 is inserted with the insertion. The eyelet portion 4b and the spring portion 8a elastically contact and lock, and the assemblability is improved.

[Brief description of the drawings]

FIG. 1 is a front view of a variable resistor according to the present invention.

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

FIG. 3 is a front view of a cover according to the variable resistor of the present invention.

FIG. 4 is a rear view of a cover according to the variable resistor of the present invention.

FIG. 5 is a sectional view taken along line BB in FIG. 3;

FIG. 6 is a front view of a conventional variable resistor.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

FIG. 8 is a plan view of an insulating substrate according to a conventional variable resistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating board 1a recess 2 Resistor 3 1st terminal 4 2nd terminal 4a recess 4b Eyelet part 5 Rotating body 5a Driver groove 5b Hole 5c Cylindrical part 6 Slider 7 Case 7a Lower side surface 7b Upper side surface 7c Step portion 7d Opening 7e Front 7f Engagement 7g Back 7h Concave 7j Projection 8 Outgoing terminal 8a Spring 8b Terminal 9 Printed circuit board

Claims (7)

[Claims] An insulating substrate made of an insulating material; a resistor provided on a surface of the insulating substrate; a first terminal provided on the insulating substrate in a state of being electrically connected to the resistor; A rotator that is rotatably mounted and has a slider that slidably contacts the resistor, a second terminal that is electrically connected to the slider and that is exposed on the back surface of the insulating substrate, A case combined with a board, and a lead-out terminal having a spring property attached to the case, wherein a spring portion having a free end of the lead-out terminal is elastically contacted with the second terminal, and A variable resistor, wherein a terminal portion is disposed on the same side as the first terminal. 2. An insulating substrate made of an insulating material, a resistor provided on a surface of the insulating substrate, a first terminal provided on the insulating substrate in a state of being electrically connected to the resistor, and A rotator that is rotatably mounted and has a slider that slidably contacts the resistor, a second terminal that is electrically connected to the slider and that is exposed on the back surface of the insulating substrate, A case having an opening on a side surface and a lead-out terminal attached to the case, wherein the insulating substrate is attached to the case from a side opening side, and the second terminal is led out. While making it elastically contact the terminal,
A variable resistor, wherein a terminal portion of the lead-out terminal and the first terminal are disposed on the same surface side. 3. The variable resistor according to claim 1, wherein said case is formed of an insulating material such as a synthetic resin, and said lead terminal is formed of a metal material. 4. The case has a substantially box shape, an opening is provided in a side surface of the case, and the insulating substrate is attached to the case from an opening side of the side surface, and a spring portion of the lead-out terminal is formed in the case. 4. The variable resistor according to claim 1, wherein the variable resistor is elastically contacted with two terminals. 5. The variable resistor according to claim 4, wherein the lead-out terminal has a terminal portion located on an opening end side of the case, and a spring portion is disposed obliquely inside the opening. . 6. The variable resistor according to claim 5, wherein a concave portion is provided in the second terminal, and a spring portion of the lead terminal is elastically contacted with the concave portion. 7. The second terminal is formed of a plate-like terminal having a cylindrical eyelet portion, and the rotating body is attached to the eyelet portion, and a spring portion of the lead-out terminal is elastically connected to the eyelet portion. 7. The variable resistor according to claim 6, wherein said variable resistor is provided.