JPH10300511A - Potentiometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a potentiometer provided with a lever wherein a fall-down prevention part of coil spring whose frictional resistance is very small is formed. SOLUTION: The potentiometer comprises a case 1, a resistor substrate 8 fixed inside the case 1, a rotor 5 comprising a sliding piece 7 which slides on the resistor substrate 8, an axis part 3c born on the rotor 5 while born on the case 1 with free rotation allowed, a lever 3 allocated on the side opposite to a holding side of the rotor 5 of the axis part 3c, and a coil spring 4 whose upper end 4a is engaged with the case 1 while its lower end 4b engaged with the lever 3. The lever 3 is formed integral with a falling-down prevention part 3b being cylindrical or vessel-like projection. Relating to the case 1, a partition 1d which forms an upper side opening part 1a and a lower side opening part 1b is formed, while a guide projection 1f which supports the upper end of the coil spring 4 is formed on the lower surface of the partition 1d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a potentiometer provided with a coil spring for returning rotation of a lever. For example, the rotor in the potentiometer rotates in response to the rotation of a throttle valve of an automobile, and the rotational position of the throttle valve. A potentiometer that generates an output voltage according to the following.

[0002]

2. Description of the Related Art Conventionally, as this kind of technique, there is a technique disclosed in, for example, Japanese Patent Application Laid-Open No. 3-48701.
In this prior art potentiometer, when the rotor rotates forward and reverse, the coil spring for return rotation of the lever rotates and winds and unwinds accordingly. The prior art is
The bent portion formed on the lever prevents the coil spring from inclining and the inner surface of the coil spring from contacting the bearing portion.

[0003]

However, the above-mentioned conventional potentiometer has the effect of preventing the coil spring from inclining and contacting the bearing portion, but the lever and the shaft are separate. Therefore, there is a problem that the number of parts and the number of processing steps are large. The shaft bar is formed by insert molding a single body formed by cutting into a resin rotor. As a result, the rotor requires manual processing, requires a large number of processing steps, and increases the cost.

When the lever of the conventional potentiometer is pivotally supported on the case, one end of the coil spring is locked on the case, the other end of the coil spring is locked on the lever, and the elasticity of the coil spring is adjusted. The lever must be rotated in the opposite direction against the shaft, and the shaft hole of the lever must be fitted to the shaft rod that is fitted to the case, and caulked and fixed. There is a problem that the number of attaching steps increases.

According to the present invention, there is provided a potentiometer having a tilt preventing portion having a low friction coefficient with a coil spring by integrally forming a tilt preventing portion of a tubular or container-shaped coil spring with a lever of a potentiometer of an automobile. The purpose is to provide.

[0006]

Means for Solving the Problems The invention of claim 1 of the present invention has been made to solve the above-mentioned problems of the prior art, and comprises a case, a resistor substrate fixed in the case, and A rotor having a sliding contact piece that slides on the resistance substrate,
A shaft portion that is rotatably supported by the case and is rotatably supported by the case; a lever disposed on a side of the shaft portion opposite to the rotor holding side; an upper end locked to the case; In the potentiometer provided with a coil spring locked to the lever, the lever is formed by integrally forming a tilt preventing portion formed of a cylindrical or container-like projection and the lever.

According to a second aspect of the present invention, there is provided a rotor having a case, a resistive substrate fixed in the case, a sliding contact piece slidably contacting the resistive substrate, and a shaft fixed to the rotor and turned to the case. A shaft portion movably supported, a lever disposed on the side opposite to the rotor holding side of the shaft portion, and a coil spring having an upper end locked to the case and a lower end locked to the lever. In the potentiometer, the lever is formed by integrally forming the shaft with a cylindrical or container-shaped lever.

According to a third aspect of the present invention, in the first aspect of the present invention, the lever is formed integrally with the lever by forming the shaft portion into a tubular or container-like shape.

Further, the invention according to claim 4 is the invention according to claim 1,
Or In the invention of 3, the case forms a partition plate that forms an upper opening and a lower opening,
A guide projection for supporting the upper end of the coil spring is formed on the lower surface of the partition plate.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the guide projection is formed in a substantially arc shape and is disposed at a position substantially opposite to the shaft portion with respect to the tilt preventing portion. It is done.

According to a sixth aspect of the present invention, there is provided a case, a rotor having a resistive substrate fixed in the case, a sliding contact piece slidably contacting the resistive substrate, and a shaft fixed to the rotor and turned to the case. A shaft portion movably supported, a lever disposed on the side opposite to the rotor holding side of the shaft portion, and a coil spring having an upper end locked to the case and a lower end locked to the lever. In the potentiometer, the case accommodates the rotor and the resistance substrate, and forms an opening that is closed by a lid member, and the resistance substrate forms a through hole substantially at the center, and between the lid member and the lid member. This is because a substantially disk-shaped packing is interposed.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the packing has a projection formed on a lower surface to be fitted into a through hole, and a ring-shaped projection pressed on the lower surface of the lid member on the upper surface. It is formed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of the present invention will be described in detail with reference to FIGS. In FIG. 1, reference numeral 1 denotes a potentiometer case in which the terminal 2 is insert-formed with resin. The case 1 has a substantially cylindrical shape in which openings 1a and 1b are formed vertically. The openings 1a and 1b are integrally formed with a partition plate 1d having a shaft support 1c. In the opening 1a, as shown in FIG.
The stopper 1j which strikes the j is formed.

On the left and right sides of the outer walls of the openings 1a and 1b, ears 1k for screwing the case 1 to the vehicle body by inserting screws.
Is formed. A metal piece having a substantially C-shaped cross section is fixed to the inner wall of the ear 1k. On the lower end surface of the shaft support 1c, an annular convex portion 1g with which the upper surface of the lever 3 slides is formed.

The guide projection 1f is a projection for supporting the upper end of the coil spring 4 on the lower surface of the partition plate 1d. The guide protrusion 1f is formed and arranged in an arc shape along the inner surface of the coil spring 4, and the shaft 3
It is arranged at a position substantially opposite to c. The shape of the guide projection 1f is a shape that reduces friction with the coil spring 4, and may have a circular or elliptical cross section, for example. The number of guide projections 1f may be one or more, and is not particularly limited. When a plurality of the guide projections 1f are formed, the guide projections 1f are arranged along the inner surface of the coil spring 4.

The terminal 2 has one end protruding into the connector 1e and the other end protruding into the opening 1a. 3
Is a metal lever provided in the opening 1b on the lower surface of the partition plate 1d via the coil spring 4. The lever 3 is formed by, for example, pressing a metal plate of a cold-rolled iron plate. Note that the lever 3 may be formed of a stainless steel plate or the like. The lever 3 includes a driven part 3a to which rotation from a rotating body is transmitted, a tilt prevention part 3b disposed inside the coil spring 4 to prevent the coil spring 4 from tilting,
A shaft portion 3c that is fitted to the shaft support portion 1c is integrally formed.

The driven portion 3a is formed by bending a part of a projection integrally formed with the lever 3 at a right angle. The driven part 3a
Is formed at a position of about 180 ° with respect to the elongated hole 3d as shown in FIG. 4, and has a circular cross section. The tilt prevention portion 3b is a projection formed in a container shape by deep drawing and has a ring-shaped cross section.

The tilt preventing portion 3b has a substantially elliptical cross section as shown in FIG. 5 and has a substantially fan-shaped groove formed along the inner surface of the coil spring 4, as shown in FIG. Shape or both. As shown in FIG. 4, it is effective to arrange the tilt preventing portions 3b and 3h at a position approximately 90 ° from the long hole 3d for locking the lower end 4b of the coil spring 4, as shown in FIG. Further, the number of the tilt preventing portions 3b and 3h is not limited to one, and may be plural. In this case, the plurality of tilt prevention units 3
b and 3h are arranged in a circular shape along the inner surface of the coil spring 4.

As shown in FIG. 2, the tilt preventing portion 3b supports the lower inner side of the coil spring 4, and the upper inner side of the coil spring 4 is supported by a guide projection 1f formed below the partition plate 1d. .

The shaft portion 3c is formed at the center of the lever 3 by deep drawing as in the case of the tilt preventing portion 3b.
The driven portion 3a, the tilt prevention portion 3b, and the shaft portion 3c
It is formed in a simultaneous process by a press machine. The shaft 3c is
The rotor 5 is inserted through the shaft support 1c and
Is caulked and fixed. The shaft portion 3c includes a shaft support portion 3e that is rotatably fitted to the shaft support portion 1c, a shaft fixing portion 3f that is fixed to a shaft hole 5a of the rotor 5, and a crimping portion 3g that is crimped and fixed to the rotor 5. It becomes.

The upper end 4a of the coil spring 4 is
And the lower end 4b is engaged with the long hole 3d of the lever 3 at the lower end of the partition plate 1d.
The coil spring 4 is a spring that automatically returns the turned lever 3 and the rotor 5 and has elasticity to turn the coil spring 4 in the direction of arrow A.

The rotor 5 is made of resin such as PTB resin and is formed in a disk shape. The rotor 5 is fixed to the upper surface by heat crimping the sliding contact piece 7 or by crimping and fixing the sliding contact piece 7. 6 is a thin ring-shaped spring washer,
Made of metal spring material. The spring washer 6 is a so-called wave washer, which is bent into three waves to provide elasticity and presses the lower surface of the rotor 5. The spring washer 6 is arranged around the shaft support 1c and is interposed between the partition plate 1d and the rotor 5.

The sliding contact 7 is made of a conductive spring member, and is a brush contact 7a that contacts a resistance (not shown) of the resistance substrate 8.
Are fixed. The resistor substrate 8 has a resistor (not shown) printed on the lower surface and a through hole 8b formed in the center. The resistor substrate 8 includes a terminal 2 disposed in the opening 1a.
A lead terminal 8a to be soldered is fixed to the end.

Reference numeral 9 denotes a substantially ring-shaped packing made of rubber or the like, which is interposed between the resistance substrate 8 and the lid member 10.
The packing 9 is substantially disk-shaped, has a columnar projection 9a formed in the center of the lower surface, and has a ring-shaped projection 9 inside the peripheral portion of the upper surface.
b is formed. The protrusion 9a is fitted in the through hole 8b, whereby the packing 9 is positioned on the resistance substrate 8,
The periphery of the projection 9 a of the packing 9 is in close contact with the resistance substrate 8. The ring-shaped projection 9b is in close contact with the lower surface of the lid member 10 by fitting the lid member 10 into the opening 1a. Thus, the resistance substrate 8 in the opening 1a is sealed. The lid member 10 fits into the opening 1a and is fixed by ultrasonic welding or the like.

The embodiment of the present invention is configured as described above. Next, an assembling procedure will be described in detail. The lever 3 is stamped and bent from a metal plate by a press machine, and simultaneously forms the tilt prevention portion 3b and the shaft portion 3c. Since the tilt preventing portion 3b and the shaft portion 3c are formed integrally with the lever 3, a shaft bar made of a separate member is not required. This eliminates the need for cutting the shaft bar, thereby reducing the number of parts and the number of assembling steps, and reducing costs such as material costs. The rotor 5 does not need to be insert-molded with a shaft bar unlike the related art, and therefore can be formed of inexpensive resin.

The upper end 4a of the coil spring 4 is engaged with the engaging portion 1h of the case 1, and the lower end 4b is inserted into the long hole 3d of the lever 3. The lever 3 is turned in the direction of arrow B and
The shaft portion 3c is inserted into the shaft support portion 1c with elasticity in the direction. At this time, since the lever 3 integrally forms the shaft portion 3c, the shaft portion 3c inserted into the shaft support portion 1c serves to support and position the lever 3, so that the lever 3 is connected to the shaft support portion 1c. In addition, the work of mounting against the coil spring 4 becomes easy. Then, when the hand is released from the lever 3, the lever 3 rotates in the direction of arrow A, and the striking portion 3j strikes the stopper 1j and stops.

The shaft 3 protruding from the shaft support 1c of the case 1
c, the rotor 5 is inserted via the spring washer 6. The crimped portion 3g at the tip of the shaft portion 3c is pushed into and fitted into the shaft hole 5a of the rotor 5 and fixed by caulking. Spring washer 6
Presses the rotor 5 and presses the rotor 5 and the case 1 by compressing the shaft hole 5a fitted to the shaft stopper 3f.

The lead terminal 8a of the resistance board 8 to which the sliding contact piece 7 is fixed is soldered to the terminal 2, and the resistance board 8 is fitted into the opening 1a. The protrusion 9a of the packing 9 is inserted into the through hole 8b.
And the packing 9 is placed on the resistance substrate 8. The lid member 10 is fitted into the opening 1a of the case 1 and the periphery of the lid member 10 is ultrasonically welded.

The packing 9 has a projection 9a formed on the resistance substrate 8
Is positioned by fitting into the through hole 8b. Then, the packing 9 is covered with the lid member 10 from above and pressed, so that the lower surface has the periphery of the projection 9a in close contact with the upper surface of the resistance substrate 8 to close the through hole 8b, and the upper surface has the ring-shaped protrusion 9b. The lower surface of the lid member 10 is pressed and compressed to elastically support the resistance substrate 8 made of a ceramic substrate or the like. Since the tilt prevention portion 3b of the lever 3 is cylindrical or container-shaped, the coefficient of friction with the coil spring 4 is extremely low, and the lever 3 and the coil spring 4 rotate smoothly.

The operation will be described in detail. When the lever 3 rotates, the lower end 4b of the coil spring 4 rotates together with the lever 3 so that the radius decreases and the axis of the coil spring 4 tends to fall. At this time, the tilt preventing portion 3b and the guide projection 1f prevent the coil spring 4 from tilting. Thus, when the lever 3 rotates, the inner surface of the coil spring 4 does not rub against the shaft support 1c of the case 1, and the rotation of the lever 3 and the coil spring 4 becomes smooth.

Next, another embodiment of the structure for stopping the shaft 3c and the rotor 5 will be described in detail with reference to FIGS. 6 (a) to 6 (d). FIG. 6A shows a shaft portion 3c-1 having one step portion.
Is formed in a container shape with a bottom, and a shaft stopper 3f-1 for press-fitting into the shaft hole 5a of the rotor 5 is formed at the tip. The rotor 5 is fixed by press-fitting the shaft hole 5a into the shaft stopper 3f-1.

FIG. 6B shows a shaft 3 having one step.
c-2 is formed into a cylindrical shape with a bottom, and a shaft stop portion 3f-2 which is fitted into the shaft hole 5a of the rotor 5 at the tip and is fixed by caulking.
Is formed. The rotor 5 has a shaft hole 5a formed by a shaft stopper 3f-
2 and crimped and fixed.

FIG. 6C shows a shaft 3 having one stepped portion.
c-3 is formed in a cylindrical shape without a bottom, and has a shaft fitting portion 3f fitted at its tip into a shaft hole 5a of the rotor 5 and fixed by split crimping.
-3. The rotor 5 has the shaft hole 5a
It is press-fitted into f-3 and crimped and fixed.

FIG. 6D shows a shaft 3 having two steps.
c-4 is formed in a cylindrical shape without a bottom, and a mounting portion 3g-4 of the push nut 11 for press-fitting and fixing at the forefront, and a shaft stop portion 3f-4 fitted on the shaft side 5a of the rotor 5 at the hand side.
Is formed. The rotor 5 has a shaft hole 5a formed by a shaft stopper 3f-
4 and the push nut 11 is pressed into the mounting portion 3g-4 and fixed to the shaft portion 3c-4.

FIG. 6E shows a stepped shaft stopper 3f-5 into which the shaft hole 5a is fitted, and a groove 3g into which the C ring 12 is fitted.
5, and a shaft portion 3c-5 having a bottomless cylindrical shape. The shaft 3c-5 has a C ring 1 at the tip.
The second fitting groove 3g-5 is formed, and a shaft stopper 3f-5 that fits into the shaft hole 5a of the rotor 5 is formed on the near side of the fitting groove 3g-5.

[0036]

Since the present invention is constructed as described above, the following effects can be obtained. According to a first aspect of the present invention, there is provided a case, a rotor having a resistance substrate fixed in the case, a sliding contact piece slidably contacting the resistance substrate, and a shaft fixed to the rotor and rotatable to the case. A potentiometer comprising a shaft portion pivotally supported by a shaft portion, a lever disposed on the side opposite to the rotor holding side of the shaft portion, and a coil spring having an upper end locked to the case and a lower end locked to the lever. Since the lever is integrally formed with the tilt preventing portion formed of a cylindrical or container-shaped projection, the tilt of the coil spring can be prevented without increasing the number of parts.
Further, since the tilt preventing portion is formed of a cylindrical or container-like projection, the friction with the coil spring is small, and the rotation of the lever and the coil spring can be made smooth.

According to a second aspect of the present invention, there is provided a rotor having a case, a resistance substrate fixed in the case, a sliding contact piece slidably contacting the resistance substrate, and a shaft fixed to the rotor and fixed to the case. A shaft portion rotatably supported, a lever disposed on the side of the shaft portion opposite to the rotor holding side, and a coil spring having an upper end locked to the case and a lower end locked to the lever. In the above potentiometer, the lever is formed integrally with the lever by forming the shaft portion into a cylindrical or container-like shape, so that the number of parts and the number of assembling steps can be reduced and cost can be reduced. In addition, when the coil spring and the lever are mounted on the case, the shaft portion serves to position and support the lever, so that the mounting operation is facilitated.

According to the third aspect of the present invention, the first aspect is provided.
In the invention, the lever is formed integrally with the lever so that the shaft portion is formed in a tubular shape or a container shape, so that the tilt prevention portion and the shaft portion can be processed in the same processing step without increasing the number of parts. At the same time, and there is no need to cut the shaft part, so that the cost can be reduced.

Further, the invention of claim 4 provides the above-mentioned claim 1,
Or In the invention of 3, the case forms a partition plate that forms an upper opening and a lower opening,
By forming the guide projection for supporting the upper end of the coil spring on the lower surface of the partition plate, the inclination of the coil spring can be prevented more reliably without increasing the number of parts.

According to the fifth aspect of the present invention, the fourth aspect is provided.
In the invention, the guide projection is formed in a substantially arc shape and is disposed at a position substantially opposite to the shaft portion with respect to the tilt prevention portion, so that the tilt prevention portion is disposed at a friendly position. Thus, the tilting of the coil spring can be reliably prevented.

According to a sixth aspect of the present invention, there is provided a rotor having a case, a resistance board fixed in the case, a sliding contact piece slidably in contact with the resistance board, and a shaft fixed to the rotor and attached to the case. A shaft portion rotatably supported, a lever disposed on the side of the shaft portion opposite to the rotor holding side, and a coil spring having an upper end locked to the case and a lower end locked to the lever. In the potentiometer, the case houses the rotor and the resistance substrate, and forms an opening that is closed by a lid member, and the resistance substrate forms a through hole substantially at the center and is formed between the resistance substrate and the lid member. By interposing a substantially disk-shaped gasket, it is possible to improve the hermeticity of the inside of the opening of the case and to improve the impact resistance of the resistance substrate made of ceramic or the like. Further, the packing can be disposed simply by being placed at the center of the resistance substrate, so that it is easy to assemble.

According to the seventh aspect of the present invention, the sixth aspect is provided.
In the invention of the present invention, the packing has a projection formed on the lower surface to fit into the through-hole, and a ring-shaped projection formed on the upper surface so as to be pressed against the lower surface of the lid member, so that the ring-shaped projection is pressed against the lid member. The impact resistance of a resistance substrate made of ceramic or the like can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a view showing an embodiment of the present invention, and is an enlarged central longitudinal sectional view.

FIG. 3 is an enlarged central longitudinal sectional view of a lever showing the embodiment of the present invention.

FIG. 4 is an enlarged bottom view showing the embodiment of the present invention.

FIG. 5 is an enlarged bottom view showing another embodiment of the present invention.

FIG. 6 is a view showing another embodiment of the present invention;
(A) is an enlarged sectional view of an essential part showing an embodiment when a shaft portion of a lever is press-fitted into a shaft hole of a rotor, and (b) is a case where a shaft portion of a lever is crimped and fixed to a shaft hole of a rotor. It is an important section enlarged sectional view showing an embodiment, (c) is an important section enlarged sectional view showing an embodiment when a shaft part of a lever is split and fixed by a shaft hole of a rotor, and (d) is a push. It is an important section expanded sectional view showing an embodiment in which a shaft part of a lever is fixed to a shaft hole of a rotor with a nut, and (e) is an example in which a shaft part of a lever is fixed to a shaft hole of a rotor with a C-ring. It is a principal part expanded sectional view which shows a form.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 1a, 1b Opening 1d Partition plate 1f Guide projection 3 Lever 3b, 3h Tilt prevention part 3c Shaft part 4 Coil spring 4a Upper end 4b Lower end 5 Rotor 7 Sliding contact piece 8 Resistance board 8b Through hole 9 Packing 9a Protrusion 9b Ring Projection 10 Lid member

Claims (7)

[Claims] 1. A case (1), a resistance board (8) fixed in the case (1), and a rotor (5) having a sliding contact piece (7) slidingly contacting the resistance board (8). A shaft portion (3c) which is axially fixed to the rotor (5) and is rotatably supported by the case (1); and a shaft portion (3c) arranged on the side opposite to the holding side of the rotor (5). A potentiometer comprising a lever (3) and a coil spring (4) having an upper end (4a) locked to the case (1) and a lower end (4b) locked to the lever (3). 3) A potentiometer in which the levers (3) are integrally formed with the tilt preventing portions (3b) and (3h) formed of cylindrical or container-like projections. 2. A case (1), a resistance board (8) fixed in the case (1), and a rotor (5) having a sliding contact piece (7) slidingly contacting the resistance board (8). A shaft portion (3c) which is axially fixed to the rotor (5) and is rotatably supported by the case (1); and a shaft portion (3c) arranged on the side opposite to the holding side of the rotor (5). A potentiometer comprising a lever (3) and a coil spring (4) having an upper end (4a) locked to the case (1) and a lower end (4b) locked to the lever (3). 3) A potentiometer characterized in that the shaft portion (3c) is formed in a tubular or container-like shape with the lever (3). 3. A potentiometer according to claim 1, wherein said lever (3) is formed integrally with said lever (3) by shaping said shaft portion (3c) into a cylindrical or container-like shape. 4. The invention according to claim 1, wherein the case (1) forms a partition plate (1d) forming an upper opening (1a) and a lower opening (1b). And a coil spring (4) is provided on the lower surface of the partition plate (1d).
A guide projection (1f) for supporting an upper end of the potentiometer. 5. The invention according to claim 4, wherein the guide projection (1f) is formed in a substantially circular arc shape, and is substantially parallel to the shaft portion (3c) with respect to the tilt prevention portions (3b) and (3h). A potentiometer, which is arranged at an opposite position. 6. A case (1), a resistance board (8) fixed in the case (1), and a rotor (5) having a sliding contact piece (7) slidably contacting the resistance board (8). A shaft portion (3c) which is axially fixed to the rotor (5) and is rotatably supported by the case (1); and a shaft portion (3c) arranged on the side opposite to the holding side of the rotor (5). A potentiometer comprising a lever (3) and a coil spring (4) having an upper end (4a) locked to the case (1) and a lower end (4b) locked to the lever (3). 1) forms an opening (1a) that accommodates the rotor (5) and the resistance substrate (8) and is closed by a lid member (10), and the resistance substrate (8) has a through hole substantially at the center. (8b) and a substantially disc-shaped packing (9) interposed between the cover member (10) and the cover member (10). Potentiometer. 7. The packing according to claim 6, wherein the packing (9) has a projection (9a) formed on the lower surface thereof so as to fit into the through hole (8b), and is pressed against the lower surface of the lid member (10) on the upper surface. A potentiometer characterized in that a ring-shaped projection (9b) is formed.