KR20060112606A - Variable resistor - Google Patents

Abstract

A variable resistor is provided to increase operation reliability by preventing terminals from being short-circuited by preventing diffusion of coating material between terminals. A variable resistor includes an insulation substrate(7), plural mount holes(7b), plural terminals(10), a support unit(11), and a contact unit. A resistor and a condenser are formed on a planar insulation substrate. The mount holes are formed on one end portion of the insulation substrate. The terminals are fixed on the mount holes and connected to the resistor and the condenser. The terminals are elongated from one side portion of the insulation substrate to the outside. The support unit couples a fixing portion of the terminal to the insulation substrate. The contact unit is contacted with the resistor and the condenser. Insulation frame portions(11b,11c) are elongated between the fixing portions of the terminals, which are fixed on the insulation substrate, in a direction crossing a planar surface of the insulation substrate.

Description

Variable Resistors {VARIABLE RESISTOR}

1 is a cross-sectional view showing a variable resistor of the present invention.

2 is a front view showing an insulating substrate and a holding member of the variable resistor of the present invention.

3 is a cross-sectional view taken along line 3-3 of FIG. 2 of the present invention.

4 is a cross-sectional view taken along line 4-4 of FIG. 2 of the present invention.

5 is a front view showing an insulating substrate on which the terminals of the variable resistor of the present invention are fixed.

6 is a rear view showing an insulating substrate on which the terminals of the variable resistor of the present invention are fixed.

FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. 5 of the present invention. FIG.

8 is a front view showing an insulated substrate of the variable resistor of the present invention.

9 is a cross-sectional view showing a conventional variable resistor.

Explanation of symbols on the main parts of the drawings

1: control shaft

1a: control panel

1b: shaft part

1c: drive unit

2: bearing

2a: Donation

2b: barrel

3: driving body

3a: substrate portion

3b: stopper part

3c: non-circular hole

3d: arc shaped convex

4: leaf spring

5: Sliding seat

5a: round hole

5b: Boss

6: Slider

6a: Donation

6b: contact part

7: insulated substrate

7a: through hole

7b: mounting hole

7c: groove

7d: groove

8: resistor

8a: lead part

8b: electrode part

9: current collector

9a: lead part

9b: electrode part

10: terminal

10a: Eyelet part

11: holding member

11a: first opening

11b: stonework

11c: stonework

11d: through hole

11e: second opening

11f: stone wall

12: cover

13: rivet

Japanese Laid-Open Patent Publication 2000-277308

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a variable resistor which is used for an acoustic device or the like and is rotated by an operation knob to adjust a volume and the like.

As a structure of a conventional variable resistor, a rotating body having a conductive sliding element is opposed to an insulating substrate on which a resistor or the like held in a housing is formed, and the rotating body is rotated in accordance with a rotating operation of the operating shaft to connect the sliding element with the sliding element. It is known that it is the structure which detects the change of a resistance value by sliding a resistor in contact (for example, refer patent document 1).

The structure of this conventional variable resistor is shown in FIG. 9 is a cross-sectional view showing a conventional variable resistor.

In the figure, the bearing 51 is formed by integrally molding a zinc cylinder in a substantially cylindrical shape. The bearing 51 is provided with a cylindrical shaft portion 51a, and the shaft portion 51a is formed with a through hole 51c into which the operation shaft is inserted.

The operation shaft 52 is made of insulating material such as synthetic resin, and is formed in a substantially columnar shape. An operation part 52a penetrating through the through hole 51c of the bearing 51 and protruding outward is provided at the front end of the operation shaft 52, and a substantially disk-shaped rotating body 52b is provided at the rear end. Is formed. The fitting shaft 52c is formed in the center of the lower surface side of this rotating body 52b, and the sliding member 53 which consists of a metal plate etc. which are electrically conductive materials is fixed to the outer side of the fitting shaft 52c. Moreover, on the upper surface side of the rotating body 52b, the uneven part 52g which consists of several mountain part and valley part which continued on the concentric circle is formed.

The drive body 54 consists of insulating materials, such as synthetic resin, and is formed in substantially ring shape. Moreover, the uneven part 54c which consists of several mountain part and valley part which continued on the concentric circle is formed in one surface of the drive body 54. As shown in FIG.

The spring member 55 consists of a metal plate with spring property, such as a phosphor bronze plate or a stainless steel plate, and is formed in substantially ring shape. The spring member 55 is bent in the standing state, and the spring piece 55c is formed. This spring member 55 attaches the drive body 54 to the rotating body 52b side.

The resistance substrate 56 is made of an insulating substrate such as a phenol resin, and an arc-shaped resistor (not shown) formed by printing carbon ink or the like is provided on one surface thereof. In addition, the terminals 58 are fixed to both ends of the resistor by the eyelets 57.

The housing 59 is for holding the resistance substrate 56, the terminal 58 and the like therein, and is made of an insulating material such as synthetic resin, and the resistance substrate 56 is integrally formed by a method such as insert molding. Formed. The fitting hole 59a which penetrated with the resistance board 56 is provided in the center of this housing 59, and the frame 60 which comprises the cover of an electrical component is provided in the front part of the housing 59. As shown in FIG. The mounting boss (not shown) for attaching this is formed.

However, in the structure of the conventional variable resistor, when insert-molding an insulating substrate made of a phenol resin or the like into a housing made of an insulating material such as a synthetic resin, a very small gap is formed between the insulating substrate and the synthetic resin. And when the metal transition (whisker or migration) of the plating material of a terminal generate | occur | produced, there existed a problem that the terminal short-circuited through this clearance gap.

Therefore, an object of the present invention is to solve the above problems and to provide a variable resistor with high reliability, which is unlikely to cause short circuit defects between terminals even when the insulating substrate is insert-molded with a synthetic resin housing. .

Means to solve the problem

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in this invention, as a 1st solution means, it adheres to the plate-shaped insulated substrate in which the resistor and the collector were formed, the some mounting hole provided in the one end side of this insulated substrate, and this some mounting hole. The plurality of terminals extending outwardly from one end side of the insulating substrate, and the fixing portions of the plurality of terminals and the insulating substrate are embedded in the state where the resistor and the current collector are exposed. A holding member made of synthetic resin, and a sliding member for sliding the resistor and the current collector on the upper surface of the insulating substrate; It was set as the structure which provided the insulating protrusion part extended in the direction.

Moreover, as a 2nd solution means, the recessed groove part or the slit part which penetrated was provided between the fixed part of the said multiple terminal of the said insulated substrate, and a part of resin of the holding member made of the synthetic resin in the groove part or the slit part. It was set as the structure which formed the said protrusion part by filling with.

Moreover, as a 3rd solution means, it was set as the structure which provided the said groove part or the slit part continuously to the edge of the said insulated substrate.

Moreover, as a 4th solution means, the said protrusion part was set as the structure provided in the both surfaces of the said insulated substrate.

Moreover, as a 5th solution means, it was set as the structure by which tin plating was given to the surface of the said terminal.

To practice the invention  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is shown to FIG. 1 is a sectional view showing a variable resistor of the present invention, FIG. 2 is a front view showing an insulating substrate and a holding member of the present invention, FIG. 3 is a sectional view taken along line 3-3 of FIG. 2, and FIG. 4 is 4 of FIG. Fig. 5 is a sectional view taken along the line -4, Fig. 5 is a front view showing the insulated substrate to which the terminal of the present invention is fixed, Fig. 6 is a back view showing the insulated substrate to which the terminal of the present invention is fixed. Sectional drawing in FIG. 7 line, FIG. 8 is a front view which shows the insulated substrate of this invention.

In the drawing, the variable resistor of the present invention has an operating shaft 1, a bearing 2 for holding the operating shaft 1 rotatably, and a torque generating plate spring 4. Sliding body support (5) having a driving body (3) and a sliding member (6) rotatable with the rotation, and are caught by the driving body (3) and rotatable together with the driving body (3). Resistor 8 or current collector 9 which is in sliding contact with each other, is provided with an insulating substrate 7 integrally embedded in the holding member 11, a terminal 10 fixed to the insulating substrate 7, and a holding. The cover 12 covers the back side of the member 11.

The operation shaft 1 is made of an insulating material such as synthetic resin or a metal material such as aluminum, and the operating portion 1a protrudes outward from the bearing 2 and the shaft portion 1b rotatably inserted into the bearing 2. ) And a non-circular drive portion 1c protruding rearward of the shaft portion 1b. The drive body 3 is engaged with this drive part 1c, and the drive body 3 rotates with the rotation of the operation shaft 1.

The bearing 2 is formed by die-casting metal materials, such as zinc, and has the base 2a and the cylindrical part 2b. The shaft portion 1b of the operating shaft 1 is inserted through the cylindrical portion 2b, and the driving portion 1c protrudes from the base 2a side.

The drive body 3 consists of an insulating material, such as synthetic resin, and has a disk shape which has a non-circular hole (for example, small oval hole) 3c in which the drive part 1c of the operation shaft 1 is inserted in the center. Substrate portion 3a and stopper portion 3b protruding from the outer circumference of substrate portion 3a. In addition, a pair of arc-shaped convex portions 3d are provided on the circumferential edge of the non-circular hole 3c so as to face each other with the holes interposed therebetween, and the arc-shaped convex portions 3d are provided with the sliding members 5. The slide holder 5 is rotatably integrally engaged with the drive body 3 by fitting with a recess not shown.

Further, a torque generating plate spring 4 made of a metal plate having elasticity is mounted on one surface side (surface side facing the bearing 2) of the substrate portion 3a of the driving body 3, and the driving body 3 ), When the leaf spring 4 is in sliding contact with the inner surface of the base 2a of the bearing 2, torque generation (occurrence of a sense of solidity) occurs when the operating shaft 1 rotates. .

The slide receiving part 5 is formed in disk shape with insulating materials, such as synthetic resin, and has the circular hole 5a through which the drive part 1c of the operation shaft 1 is inserted in the center, and this circular hole 5a A pair of unillustrated convex portions, not shown, which face each other with a hole interposed therebetween, and a pair of concave portions, not shown, located between the convex portions are formed. The arc-shaped convex part 3d of the drive body 3 fits into this pair of recessed parts.

Moreover, the sliding member 6 which consists of an electroconductive metal plate which has elasticity is fixed to the one surface side (surface side where the drive body 3 is located) of the sliding receiver 5. The sliding member 6 has an annular base 6a and a contact portion 6b elastically bent from the base 6a, and the base 6a is provided on one surface side of the sliding receiver 5. It is fixed to some of the bosses 5b provided by a method such as fixing. This sliding member 6 rotates with the sliding receiver 5, and is in sliding contact with the resistor 8 and the electrical power collector 9 which were formed in the insulated substrate 7. As shown in FIG.

The insulated substrate 7 consists of resin laminated boards, such as a phenol resin, and is formed in flat form which has a slightly large through hole 7a in the center. In addition, as illustrated in FIG. 8, an annular current collector 9 is provided on one surface side (surface side) of the insulating substrate 7 so as to surround the periphery of the through hole 7a. In the circumference | surroundings of 9), the resistor 8 of circular arc shape partly open is provided. In this case, the resistor 8 is formed by, for example, printing a carbon paste, and the current collector 9 is formed by overcoating carbon, for example, in order to prevent sulfidation of silver after printing the silver paste.

In addition, lead portions 8a and 9a extending from one end side of the resistor 8 and the center of the current collector 9 toward one end side of the insulating substrate 7 are provided. Electrode portions 8b and 9b are provided at the front end sides of the lead portions 8a and 9a, respectively, and the electrode portions 8b and 9b are formed by overcoating some carbon on a silver paste printed with a predetermined length. It is. In addition, a part of the electrode portions 8b and 9b on the tip side is in a state where a silver pattern formed by printing silver paste is exposed, and the terminal 10 is fixed on the silver pattern so that the resistor 8 and the current collector are fixed. It is connected with (9).

Moreover, in the center part of each electrode part 8a, 9b, the some mounting hole 7b, 7b which consists of a small hole which penetrates the front and back of the insulated substrate 7 is provided, and this mounting hole 7b, 7b is provided. The plurality of terminals 10 and 10 made of a conductive metal plate are fixed to the eyelet portion 10a at the tip end formed in a cylindrical shape by drawing processing (see FIGS. 5 to 7). In this case, after the nickel base plating is given to the terminal 10, tin plating is given to this upper surface side. And since the terminal 10 is fixed to the mounting hole 7b, the terminal 10, the resistor 8, and the electrical power collector 9 are electrically connected, respectively.

In other words, in the present embodiment, the surface of the terminal 10 is solder-plated, and tin plating is performed instead of solder plating to lead-free to environmental problems.

In addition, between the plurality of mounting holes 7b and 7b of the insulating substrate 7, a groove portion 7c which is concave in the direction crossing orthogonal to the flat surface of the insulating substrate 7, that is, the plate thickness direction, is provided. Formed. This groove portion 7c is formed continuously along the electrode portions 8b, 9b in a long shape from the upper side of the mounting hole 7b to the edge of the insulating substrate 7, and this groove portion 7c is shown in FIG. As shown in 5, when the terminal 10 is fixed to the electrode parts 8b and 9b, it is formed so that it may be located between each terminal 10. FIG. On the other hand, this groove part 7c is formed in the elongate shape in the range which shields all the parts in which the silver pattern which is a part of electrode part 8b, 9b was exposed.

In addition, in the plate thickness direction, it is also similar to the other surface side (rear surface side) which opposes the one surface side in which the resistor 8 and the conductor 9 of the insulated substrate 7 were opposing the groove part 7c. The recessed portion 7d is formed. Similarly, this groove portion 7d is formed continuously in a long shape from the upper side of the mounting hole 7b to the edge of the insulating substrate 7, and the groove portion 7d is an electrode portion as shown in FIG. 6. When the terminal 10 is fixed to 8b and 9b, each terminal 10 is formed so that it may be located between the eyelet parts 10a which are cocked and become a fixed part. In other words, the same groove portions 7c and 7d are provided opposite to both sides of the insulating substrate 7, and these groove portions 7c and 7d are formed of at least the insulating substrate 7 provided with the respective groove portions 7c and 7d. Between each part (fixed part) of the terminal 10 in one surface side and the other surface side, it is formed in elongate shape in all the boundary ranges in the extension direction of the said terminal 10. As shown in FIG.

Although the grooves 7c and 7d can be easily formed by press working or the like, they may be formed by performing laser processing on the front and back surfaces of the insulating substrate 7, and in this case, the occurrence of cracks and the like with high accuracy can be achieved. The groove portions 7c and 7d can be formed without. The grooves 7c and 7d may be V-shaped, U-shaped, or any of the shapes, but the U-shaped is most suitable for workability and the like.

Although not shown, instead of the groove portions 7c and 7d, the slits that penetrate the front and rear surfaces of the insulating substrate 7 may be provided continuously from the upper side of the mounting hole 7b to the end edge of the insulating substrate. do.

The holding member 11 is formed in substantially rectangular shape with insulating materials, such as synthetic resin. 2 and 3, the insulating substrate 7 is integrally embedded in the holding member 11 by a method such as insert molding. A circular first opening 11a is formed on one surface side of the holding member 11, and the resistor 8 and the current collector 9 are disposed on the inner bottom of the first opening 11a. It is. In addition, the circumferential edge portion of the insulating substrate 7 and the fixing portion of the terminal 10 are integrally embedded by the holding member 11, and the bottom surface side of the insulating substrate 7 (the lower side in FIGS. 2 and 3). The terminal 10 protrudes from this.

Moreover, when the grooves 7c and 7d formed between the fixing portions of the terminal 10 of the insulating substrate 7 are integrally embedded in the holding member 11, the resin of the holding member 11 made of synthetic resin As a part is filled, the protrusion parts 11b and 11c which protrude along the shape of the groove parts 7c and 7d are formed. The protruding portions 11b and 11c protrude (extend) in a direction intersecting in a state perpendicular to the flat surface of the insulating substrate 7 between the fixing portions of the plurality of terminals 10 of the insulating substrate 7. As shown in FIG. 4, the protrusions 11b and 11c are formed on both sides of the insulating substrate 7.

In the present embodiment, tin plating is applied to the surface of the terminal 10 in place of solder plating, and lead-freeization can be realized because the solder is not coated. In connection with this, there exists a possibility that the short circuit between the terminals 10 and 10 may occur. In order to prevent this, in this embodiment, concave groove portions 7c and 7d are provided between the fixing portions of the plurality of terminals 10 of the insulating substrate 7, and synthetic resins are formed in these groove portions 7c and 7d. The protrusions 11b and 11c are formed by filling a part of the resin of the holding member 11 of the holding member 11.

At the time of insert molding of the insulating substrate 7 and the holding member 11, the protruding portions 11b and 11c form a wall, and this wall causes the insulating substrate 7 and the holding member (at the time of insert molding. 11) Since a small gap along the flat surface of the insulating substrate 7 that occurs between them can be blocked, a short circuit between the terminals 10 and 10 accompanying the generation of a whisker by tin, which tends to extend straight, is suppressed. It is supposed to be possible.

In this case, the grooves 7c and 7d are continuously provided to the edges of the insulating substrate 7 and provided on both sides (front and back sides) of the insulating substrate 7. Since the protruding portions 11b and 11c are formed to the end edge of 7), the effect of suppressing the transition or migration of the metal is improved.

11 d of through-holes are provided in the rectangular part, and the holding member 11 is inserted through the rivet 13 which consists of a rod-shaped metal material in this through hole 11d. Is mounted on the rear side of the base 2a of the bearing 2. In addition, on the other surface side opposite to the first opening portion 11a provided on one surface side of the holding member 11, a circular second opening portion 11e is similarly provided, and the driving body (11) is provided in the second opening portion 11e. The board | substrate part 3a of 3) is accommodated rotatably, and the circular arc convex part 3d is inserted through the through-hole 7a of the insulated substrate 7. As shown in FIG. Moreover, 11 f of stop wall parts for stoppers are provided in the 2nd opening part 11e, and the stopper part 3b of the drive body 3 abuts against 11 f of stone wall parts, Rotation is regulated.

In addition, the slide receiving part 5 is accommodated in the 1st opening part 11a, and a pair of recessed parts formed between a pair of convex parts which are not shown in the periphery of the circular hole 5a (not shown) ), The slide receiving body 5 and the driving body 3 are integrated by fitting the arc-shaped convex portion 3d of the driving body 3 inserted into the through hole 7a of the insulating substrate 7. It is possible to rotate. That is, when the operation shaft 1 is rotated, the sliding part 5 also rotates as the drive body 3 rotates, and the contact part of the sliding part 6 fixed to the sliding part 5 ( 6b) and the resistor 8 and the conductor 9 formed in the insulating substrate 7 are in sliding contact.

On the side of the first opening portion 11a of the holding member 11, a rectangular cover 12 made of an insulating material such as synthetic resin is attached, and is attached by fixing the rivet 13. That is, the holding member 11 is integrally mounted in a state sandwiched between the bearing 2 and the cover 12.

According to the embodiment of the present invention described above, a plurality of mounting holes 7b are provided on one end side of the flat insulating substrate 7 on which the resistor 8 and the current collector 9 are formed, and the plurality of mounting holes are provided. The resistor 8 is connected to the resistor 8 and the current collector 9, and the plurality of terminals 10 extending outwardly from one end side of the insulating substrate 7 are fixed to the resistor 8. And embedding the fixing portions of the plurality of terminals 10 and the insulating substrate 7 with the holding member 11 made of a synthetic resin in a state where the current collector 9 is exposed. The recessed grooves 7c and 7d are provided between the fixing portions of the plurality of terminals 10, and the grooves 7c and 7d are filled with a part of the resin of the holding member 11 made of synthetic resin. Insulating protrusions extending in a direction crossing orthogonal to the flat surface of the insulating substrate 7, that is, in the plate thickness direction. Plating consisting of tin or silver applied to the terminals 10 and 10 between the adjacent terminals 10 and 10 by the insulating protruding portions 11b and 11c at the points 11b and 11c are provided. Since transition or migration of metals such as materials (migration of whiskers and silver of tin) is suppressed, short circuits between the terminals 10 and 10 are less likely to occur, and reliability is improved.

In addition, since the protrusions 11b and 11c were formed by filling a part of the resin of the holding member 11 made of synthetic resin, the insulating substrate 7 was made of the holding member 11 made of synthetic resin. In the case of insert molding in the above, since the protrusions 11b and 11c can be easily formed from a part of the resin, the productivity is improved.

On the other hand, the protrusion parts 11b and 11c in this invention are not limited to the said Example formed with a part of resin of the holding member 11, For example, it is insulating on the flat surface of the insulated substrate 7 May be applied, and the adhesive may be formed in a direction intersecting the flat surface of the insulating substrate 7 to form a protrusion.

As described above, the variable resistor of the present invention is fixed to a plate-shaped insulated substrate on which a resistor and a current collector are formed, a plurality of mounting holes provided at one end of the insulated substrate, and a plurality of mounting holes, and thus the resistor and the current collector. And a retaining member made of a synthetic resin in which a plurality of terminals extending outwardly from one end side of the insulated substrate, the resistor and the current collector are embedded, and the fixing member of the plurality of terminals and the insulated substrate are embedded, respectively. And a sliding member sliding on the current collector, and an insulating protrusion portion extending in a direction intersecting the flat surface of the insulating substrate is provided between the fixing portions of the plurality of terminals fixed to the insulating substrate. As a result, transition or transfer of metals such as plating materials applied to the terminals between adjacent terminals is suppressed, so that short circuits between the terminals are less likely to occur. High reliability.

Further, by providing a concave groove portion or a slit portion that penetrates between the fixing portions of the plurality of terminals of the insulated substrate, and filling a part of the resin of the holding member made of synthetic resin into the groove portion or the slit portion to form a protrusion portion, When insert-molding an insulated substrate to the holding member made of synthetic resin, since the protrusions can be formed from a part of the resin, the productivity is good.

In addition, by providing the groove portion or the slit portion continuously to the end edge of the insulating substrate, the protruding portion is formed up to the end edge of the insulating substrate, so that the effect of suppressing the transition or migration of the metal is improved.

Further, since the protrusions are provided on both sides of the insulated substrate, transition or transfer of metal generated on both sides of the insulated substrate can be suppressed, and the effect can be improved.

In addition, since the surface of the terminal is plated with tin, lead-free can be realized because solder is not coated, and short-circuit between terminals accompanying the generation of whisker by tin can be suppressed. have.

Claims (5)

A flat plate-shaped insulating substrate having a resistor and a current collector, a plurality of mounting holes formed at one end of the insulating substrate, and a plurality of mounting holes and being connected to the resistor and the current collector, respectively, A plurality of terminals extending from one end side to the outside, a holding member made of a synthetic resin in which the fixing portions of the plurality of terminals and the insulating substrate are buried in the state where the resistor and the current collector are exposed, and the resistor and the current collector are slid. A sliding resistor having a sliding element, and an insulating protruding portion extending in a direction intersecting a flat surface of the insulating substrate between the fixing portions of the plurality of terminals fixed to the insulating substrate. The method of claim 1, Between the fixing portions of the plurality of terminals of the insulating substrate, a concave groove portion or a slit portion that penetrates is provided, and the protrusion portion is formed by filling a portion of the resin of the holding member made of synthetic resin into the groove portion or slit portion. A variable resistor, characterized in that. The method of claim 2, And the groove portion or the slit portion is provided continuously to the end edge of the insulating substrate. The method of claim 1, The protruding portion is provided on both sides of the insulating substrate. The method according to any one of claims 1 to 4, The surface of the said terminal is tin-plated, The variable resistor characterized by the above-mentioned.

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