WO2007142160A1

WO2007142160A1 - Variable resistor

Info

Publication number: WO2007142160A1
Application number: PCT/JP2007/061225
Authority: WO
Inventors: Takaaki Ori; Masahiko Sugimoto; Shinji Araki
Original assignee: Hokuriku Electric Industry Co., Ltd.
Priority date: 2006-06-02
Filing date: 2007-06-01
Publication date: 2007-12-13
Also published as: JPWO2007142160A1; JP5048666B2

Abstract

A variable resistor in which the contact portion of a contactor can be brought into contact with a resistor with a pressure within a proper range over a long period by using a contactor containing carbon fibers. The held portion (7b) of the contactor (9) is held by means of a holder (17) such that the tip portion of the contactor (9) containing carbon fibers is brought into contact with the surface of the resistor (5). The contactor (9) has rigidity high enough not to bend during slide operation. The holder (17) is provided with a leaf spring (25) for urging the contactor (9) toward the surface of the resistor (5) separately from the contactor (9).

Description

Specification

Variable resistor

Technical field

[0001] The present invention relates to a variable resistor provided with a contact composed of carbon fiber and synthetic resin as main raw materials.

Background art

[0002] Variable resistors have been widely used in the past as so-called position detection sensors for replacing mechanical displacement amounts such as rotation angle and movement distance with electrical information in automobiles and production machines. This type of variable resistor is used for applications such as taking out a position signal corresponding to the stepping angle of an automobile accelerator as an electrical signal. The early variable resistor contacts used for brute force applications were made of metal. However, when the metal contact is repeatedly slid on the resistor, the resistor is worn due to the difference between the hardness of the metal and the resistance of the resistor, and the variable resistor becomes unusable. There was a problem that it took a short time (until the end of the service life). In addition, when conventional metal contacts are used, a large amount of wear powder is generated by the end of the service life. This abrasion powder enters the gap between the contact portion of the contact and the resistor, making the electrical contact unstable and causing sliding noise.

[0003] Therefore, it has been proposed to form a contact by processing one or more pre-predators formed into a plate shape by impregnating a bundle of many carbon fibers with a thermosetting conductive insulating resin. (For example, refer to Patent Document 1.) o This contactor is manufactured as follows. First, the thermosetting resin in one or more prepregs is heat-cured to obtain a carbon fiber sheet. The carbon fiber sheet is cut to form one or more contact pieces to form contact pieces. Next, fold the tip of one or more contact pieces into a chevron or a right angle. In this contact, the apex bent into a mountain shape is used as a contact, or the end face of the tip bent at a right angle is brought into surface contact with the surface of the resistor.

[0004] In the contact shown in Patent Document 2, a bundle of a large number of carbon fibers is covered with a synthetic resin mixed with conductive powder to form a coating layer, and the side surface of the coating layer is formed on the surface of the resistor. And line contact or surface contact. [0005] In the conventional variable resistor using such carbon fibers, the contact has a structure in which a large number of carbon fibers are hardened with thermosetting resin. There is. In addition, such a variable resistor has an advantage that the generation of wear powder is remarkably reduced.

Patent Document 1: Japanese Patent Laid-Open No. 2003-51361 Fig. 1

Patent Document 2: Japanese Patent Laid-Open No. 2004-31688 FIG. 10 to FIG. 14

Disclosure of the invention

Problems to be solved by the invention

[0006] However, in the conventional variable resistor using the contact including the bundle of carbon fibers, the contact of the contact is caused by deformation or stagnation of the bundle of carbon fibers hardened or covered with the resin. The contact portion is pressed against the surface of the resistor. For this reason, the contact part cannot always be pressed against the surface of the resistor with an appropriate force. Also, the degree of contact sag changes with time, and as a result, the contact pressure of the contact part changes, and this is the cause of noise generation and the true contact point (the point where contact occurs as current flows) ).

[0007] An object of the present invention is to use a contactor including carbon fiber, and to change the contact portion of the contactor to a resistor with a pressure within an appropriate range over a long period of time. It is to provide a resistor.

Means for solving the problem

[0008] The variable resistor of the present invention includes a resistor provided on the surface of the insulating substrate, a contact portion that slides on the surface of the resistor at the tip, and is held at a position opposite to the tip. And a holder for holding the contact directly or indirectly and operating the contact when the contact is slid on the surface of the resistor. The contact is configured such that conductivity is obtained using carbon fiber and synthetic resin as main raw materials. In particular, in the present invention, the contact has rigidity so that it does not stagnate when the contact portion slides on the surface of the resistor. Further, the variable resistor of the present invention includes a force applying mechanism that is configured separately from the contact and is provided on the holder, and that applies a force to the contact to press the contact portion of the contact against the surface of the resistor. . [0009] The configuration in the case of forming the contact using carbon fiber and synthetic resin as the main raw materials may be any as long as the required electrical conductivity and mechanical strength can be obtained. . For example, the contacts may be integrally formed with a carbon fiber mixed resin in which carbon fiber chips are randomly mixed to obtain conductivity! / !. A large number of carbon fibers are used to make a woven or non-woven fabric, and the woven or non-woven fabric is impregnated with a thermosetting insulating resin to make a plate-shaped pre-preda. It is possible to make a contact using a carbon fiber sheet that has been heat-cured. When multiple prepregs are used, multiple prepregs using woven or non-woven fabrics may be stacked, or multiple prepregs using woven and non-woven fabrics may be mixed and stacked. In addition, a carbon fiber sheet for forming a contact may be created by sandwiching one or more prepregs of woven or non-woven fabric between two prepreaders that have only the power of grease. And when forming a contactor from such a carbon fiber sheet by a cutting process, it is preferable that a cut surface comprises a contact part. This is because the carbon fiber is always exposed at the cut surface, so that the electrical conductivity of the contact portion can be ensured. If the contact is formed by integral molding, the carbon fiber should be exposed by cutting the part corresponding to the contact part.

[0010] The carbon fiber sheet is formed by laminating a plurality of pre-preders having a structure in which a plurality of carbon fibers are arranged in one direction, and the plurality of laminated pre-preders are alternately composed of a plurality of If the carbon fibers are arranged in different directions, the rigidity will increase and it will be difficult to deform the tape.

[0011] The contact of the variable resistor of the present invention has a rigidity that does not squeeze during a sliding operation. That is, since the contact does not squeeze during sliding, the contact portion can always be in contact with the resistor in a stable state. In particular, when the force applying mechanism is provided separately from the contact as in the present invention, the contact point of the contact can be pressed against the resistor with an appropriate biasing force according to the shape and rigidity of the contact. For this reason, even if the contact part of the contact begins to wear, the contact resistance does not change drastically, and no gap is formed between the contact part and the resistor so that wear powder or the like enters. Therefore, according to the present invention, the contact portion of the contact including carbon fiber is applied to the resistor with a pressure in an appropriate range over a long period. Then you can get insects.

[0012] The structure of the contactor may be any structure as long as it can be held directly or indirectly by the holder. The structure of the force applying mechanism is also arbitrary. Usually, the contact has a held portion on the opposite side of the tip. In this case, the holder has a holder main body, and the holder main body is formed with a receiving hole that opens toward the insulating substrate and slidably receives the held portion of the contact. The force applying mechanism may be configured to apply a force to the held portion of the contact and press the contact portion against the surface of the resistor in a state where the held portion of the contact is received in the receiving hole. it can. When the force applying mechanism is configured in this manner, the contact is slidably guided in the receiving hole provided in the holder body, and the contact is swayed greatly during sliding. The position of the contact will not change. In addition, since the contact portion of the contact is pressed toward the resistor while the contact is received in the receiving hole, the urging force can be applied to the contact in an appropriate direction, which is stable. A contact state can be obtained.

[0013] The receiving hole formed in the holder body may be formed to extend obliquely with respect to the surface of the resistor, or may be formed to extend in the vertical direction. When the receiving hole is formed obliquely, the contact is arranged in an inclined state with respect to the surface of the resistor. If the contact is arranged in such a state, it becomes possible to easily attract the wear powder existing on the surface of the resistor. Also, if the shape of the tip of the contactor has a cut surface in a direction that intersects the longitudinal direction of the contactor, the corner part of the contactor tip can be brought into contact with the resistor as a contact part. Become. By adopting such a contact structure, a true contact point can be formed reliably.

[0014] In addition, the force application mechanism in this case includes a spring member arranged to generate a pressing force that presses the contact portion against the surface of the resistor against the rear end portion of the held portion of the contact. Is preferable. With such a structure, a desired force can be applied to the contact with a simple structure. In addition, as a kind of spring member, arbitrary things, such as a leaf | plate spring and a coil spring, can be used.

[0015] The force applying mechanism includes a base fixed to the holder body, a squeezing part that is provided continuously with the base and extends in an inclined state toward the resistor, and a squeezing part. Provided A spring member having a contact mounting function including a contact mounting portion to which a held portion of the contact is mechanically mounted can also be configured. The spring member having such a contact mounting function can be formed separately from the contact including carbon fiber. For this reason, the contactor can be manufactured easily because the contactor is provided with rigidity that does not squeeze when it is slid. Thus, the number of manufacturing steps and manufacturing cost of the variable resistor can be reduced.

[0016] The material of the spring member having a contact mounting function is arbitrary. However, when a metal spring member is used, the mechanical connection between the spring member and the contact can be achieved easily and reliably. The structure of the contact mounting portion for mounting the contact is arbitrary, and it is preferable that the contact is mechanically held by a fitting structure, a caulking structure, a clamping structure, or the like. With such a structure, it is possible to simultaneously achieve both mechanical connection and electrical connection between the contact member that uses carbon and the contact member that uses an adhesive and the spring member. Therefore, it is possible to prevent an electrical connection failure. Prior to installation, the contact surface of the contact with the contact holding part should be cut and Z or polished to ensure that the internal carbon fibers are in contact with the contact holding part. Is preferred.

Brief Description of Drawings

FIG. 1 is a longitudinal sectional view showing an example of the best mode for carrying out a variable resistor according to the present invention.

FIG. 2 is a perspective view of a contact used in the variable resistor of FIG.

FIG. 3 is an enlarged cross-sectional view taken along line AA in FIG.

FIG. 4 is an enlarged view of an edge portion of a contact piece used in the variable resistor of FIG.

FIG. 5 is a side view showing a second example of the best mode for carrying out the variable resistor according to the present invention.

FIG. 6 is a side view showing a third example of the best mode for carrying out the variable resistor according to the present invention.

FIG. 7 is a longitudinal section showing a fourth example of the best mode for carrying out the variable resistor according to the present invention. FIG.

圆 8] (A) is an exploded perspective view of a rotor portion used when the variable resistor according to the present invention is applied to a rotary variable resistor, and (B) is after assembly of the main part of the variable resistor. It is a perspective view which shows the state.

FIG. 9 (A) is an exploded perspective view of another rotor portion used for the rotary variable resistor, and FIG. 9 (B) is a perspective view showing the assembled rotor portion.

FIG. 10 (A) is an exploded perspective view of still another rotor unit used in the rotary variable resistor, and FIG. 10 (B) is a perspective view showing the assembled rotor unit.

FIG. 11 (A) is an exploded perspective view of still another rotor unit used in the rotary variable resistor, and FIG. 11 (B) is a perspective view showing the assembled rotor unit.

[FIG. 12] (A) to (C) respectively show partial longitudinal sectional views of still another embodiment of a linear motion type variable resistor to which the present invention is applied.

13] A diagram showing a schematic configuration of a main part of another embodiment of the variable resistor of the present invention.

FIGS. 14A and 14B are an exploded perspective view of a spring member for holding a contact that can be used in the variable resistor shown in FIG. 13, and an exploded perspective view including a holder.

15] (A) and (B) are an exploded perspective view of a spring member for holding a contact that can be used in the variable resistor shown in FIG. 13, and an exploded perspective view including a holder.

FIGS. 16A and 16B are an exploded perspective view of a spring member for holding a contact that can be used in the variable resistor shown in FIG. 13, and an exploded perspective view including a holder.

FIG. 17 (A) is a perspective view showing still another example of a holding spring member using a leaf spring;

(B) is an exploded perspective view for explaining a case where a contact is attached to the holding spring member, and (C) is a perspective view of a state where the contact is attached to the holding spring member.

FIG. 18 (A) is a perspective view showing still another example of a holding spring member using a leaf spring;

[FIG. 19] (A) to (C) show perspective views of other examples in the case where the holding spring member is made of a spring wire! / Speak. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a first example of an embodiment of a variable resistor according to the present invention will be described in detail with reference to FIGS. Fig. 1 is a vertical cross-sectional view of the variable resistor of this example, Fig. 2 is a perspective view of a contact used in the variable resistor of this example, Fig. 3 is an enlarged cross-sectional view taken along line AA in Fig. 2, and Fig. 4 Fig. 4 is an enlarged view of a corner portion of a contact piece used in the variable resistor of this example.

The variable resistor of this example has a structure in which the resistor 5 is linear, and the contact 9 reciprocates on the surface of the resistor 5 linearly. As shown in FIG. 1, in this variable resistor 1, a resistor 5 is linearly provided with a predetermined length on the surface of a heat-resistant insulating substrate 3 such as a ceramic substrate. The resistor 5 is formed by printing a linear resistor pattern on the insulating substrate 3 using a resistor paste and then firing the resistor pattern. The resistor 5 may be formed by naturally drying the applied resistor paste, or may be a material obtained by cutting a resin electrical resistance film and pasting it on the surface of the insulating substrate 3.

The contact 9 has two contact pieces 7 that come into contact with the surface of the resistor 5. The contactor 9 is formed of a carbon fiber sheet having conductivity and formed using carbon fibers 11 and a synthetic resin as main raw materials. The two contact pieces 7 are positioned between the tip 7a, the base 7b, and the tip 7a and the base 7b, each having a contact 7s (FIG. 4) that slides on the surface of the resistor 5. And a stagnation part 7c. The base portions 7b of the two contact piece 7 are formed integrally with the held portion 7d.

When manufacturing the contact 9 used in the present embodiment, as shown in FIG. 3, an epoxy substrate is formed on a base material in the form of a woven fabric or a non-woven fabric formed using a large number of carbon fibers 11. A plurality of pre-predas 15 (three in the example of FIG. 3) prepared by impregnating a thermosetting insulating resin 13 such as a resin are prepared. In the example of FIG. 3, a pre-predder using a base material in which a plurality of carbon fibers 11 are arranged in a bundle is used. The central prepreg and the two prepreaders on both sides in the thickness direction are overlapped so that the extending directions of the carbon fibers are different. Next, heating is performed under pressure in a state where a plurality of prepreaders 15 are stacked, and the thermosetting resin 13 in the prepreader 15 is heat-cured to form a carbon fiber sheet. Next, this carbon fiber sheet was cut and processed as shown in FIG. A contact 9 having a contact piece 7 is formed. In this example, the type and hardness of the synthetic resin and the amount of carbon fiber are determined so that the contactor 9 has a rigidity that does not squeeze when performing the sliding operation.

[0022] As described above, the carbon fiber sheet used in this example is configured by laminating the three pre-preders 15 having a structure in which a plurality of carbon fibers 11 are arranged in the same direction. The pre-preder 15 made of three carbon fiber sheets is laminated and integrated together so that a plurality of carbon fibers 11 are alternately arranged in different directions. In other words, this carbon fiber sheet is composed of a pre-predator having a carbon fiber 11 oriented in a direction perpendicular to the longitudinal direction of the contact piece 7 between the two pre-preders 15 having the carbon fiber 11 oriented in the longitudinal direction of the contact piece 7. It has a structure in which 15 sheets are sandwiched together. The structure of the carbon fiber sheet is not limited to this example, and carbon fiber sheets having various structures can be used. For example, the contact may be integrally formed using carbon fiber mixed resin in which short chips of carbon fiber chips are randomly mixed.

[0023] As shown in Figs. 2 and 4, the two contact pieces 7 have a cutting surface extending from the distal end portion 7a to the base portion 7b as a distal end surface 7f extending in a direction crossing the direction of the force. . Also, as shown in FIG. 4, the contact 9 is a holder 17 which will be described later in an inclined state so as to face one side 7g force resistor 5 of the two side surfaces located in the thickness direction of the contact piece 7. Retained. A part of the corner portion 7k formed between the tip surface 7f of the contact piece 7 and one side surface 7g constitutes the contact portion 7s. The corner portion 7k is located in a region surrounded by the tangent plane S1 with respect to the tip surface 7f and the tangent plane S2 with respect to the side surface 7g of the stagnation portion 7c.

As shown in FIG. 1, the contact 9 is held by a holder 17 made of insulating resin and slides linearly on the surface of the resistor 5 along the longitudinal direction of the resistor 5. In FIG. 1, the illustration of a case that fixes the positional relationship between the holder 17 and the insulating substrate 3 and supports the holder 17 so as to be slidable along the longitudinal direction of the resistor 5 is omitted. An inclined through hole 23 is formed in the holder body 18 of the holder 17. In the inclined through hole 23, the contact 9 is accommodated so that the tip of the contact piece 7 is exposed. In the inclined through hole 23, one side surface 7g of the contact piece 7 of the contact 9 accommodated in the inclined through hole 23 is opposed to the surface of the resistor 5 and forms a predetermined angle with the surface. It is formed to do. The inclined through hole 23 The cross-sectional shape is determined so that the accommodated contact 9 slides in the inclined through hole 23. In the present embodiment, the inclined through hole 23 constitutes a receiving hole for slidably receiving the contact 9. Further, on the holder body 18, the end of the held portion 7d of the contact 9 inserted in the inclined through hole 23 is pushed in the longitudinal direction of the contact 9, so that the contact 7s is brought into contact with the surface of the resistor 5. A force applying mechanism 24 for generating a contact force is provided. The force applying mechanism 24 includes a leaf spring 25 and a fixing member 27 that fixes the leaf spring 25 on the holder body 18. The leaf spring 25 is placed on the holder main body 18 and the base end thereof is fixed to the holder main body 18 by a fixing portion 27 that is heat-deformed. The leaf spring 25 is configured to generate a force that pushes the end of the held portion 7d of the contact 9 toward the resistor 5 at the free end of the tip. In this example, since the contact 9 has such rigidity that it does not crawl during sliding, the contact portion 7s does not jump (skip) when the contact 9 is moving. . Further, the relative position of the contact portion 7s with respect to the holder 18 does not change. FIG. 5 is a longitudinal sectional view of the second embodiment of the variable resistor according to the present invention. This example shows a modification of the first embodiment shown in FIG. Therefore, in FIG. 5, the same members as those shown in FIG. 1 are given the same reference numerals as those shown in FIG. In this variable resistor, a linear spring 29 is used as a spring member of the force applying mechanism 24. The linear spring 29 is formed by applying a bending force to the linear spring material. The linear spring 29 includes a curved portion 29a formed by bending a linear spring member into a U shape, and two linear portions 29b extending in parallel from the curved portion. The curved portion 29a includes a locking portion 29c that is bent at a right angle with respect to the linear portion 29b and is formed by being folded back at an intermediate portion. The curved portion 29a including the locking portion 29c looks V-shaped in the state shown in FIG. This locking portion 29 c is fitted in a locking hole 17 a formed in the holder 17. The locking hole 17a penetrates the holder body 18 in the thickness direction, and a locking projection 17b is formed at the entrance of the locking hole 17a. The leading end of the locking portion 29c is locked to the locking projection 17b to prevent the locking portion 29c from coming off. The end portion force of the linear portion 29b of the wire spring 29 The surface force of the holder body 18 is bent in the separating direction to form the pressing portion 29d. The contact 9 is pressed against the resistor 5 by the pressing part 29 9d. Other configurations are shown in Fig. 1. Since it is the same, description is abbreviate | omitted.

FIG. 6 is a longitudinal sectional view of still another embodiment of the variable resistor according to the present invention. This embodiment is also a modification of the embodiment of FIG. Therefore, in FIG. 6, the same members as those shown in FIG. 1 are given the same reference numerals as those shown in FIG. In the variable resistor of this example, a torsion spring 31 is used as a spring member used in the force applying mechanism 24. In this example, a torsion spring fixing portion 28 is formed in a body on one end portion of the holder body 18 of the holder 17. The torsion spring fixing portion 28 is disposed at a position close to one side in the width direction of the holder body 18 (direction perpendicular to the paper surface of FIG. 6). In the torsion spring fixing portion 28, a spring support protrusion 30 extending in parallel with the surface of the holder body 18 is provided on the surface opposite to the side where the contact 9 is present. The coil portion 31 a of the torsion spring 31 is passed through the spring support protrusion 30. One end (not shown) of the torsion spring 31 is fixed to the torsion spring fixing part 28. The other end (free end) 31b of the torsion spring 31 is in contact with the end of the supported portion 7d of the contact 9. The torsion spring 31 applies a downward force to the end portion of the supported portion 7b of the contact 9 from the other end portion 31b. By this force, the contact portion 7s of the contact piece 7 is pressed against the surface of the resistor 5 and is turned. Other configurations are the same as those of the embodiment shown in FIG.

FIG. 7 is a longitudinal sectional view of still another embodiment of the variable resistor according to the present invention. In the variable resistor of this example, a compression coil spring 33 is used as the force applying means of the force applying mechanism 24. The holder body 18 of the holder 17 is provided with a bulging portion 19. The holder body 18 and the bulging portion 19 are formed with inclined holes 23 for receiving the contacts 9. The inclined hole 23 is closed at the upper end and constitutes a receiving hole. In the inclined hole 23, a coil spring 33 is housed for pressing the contact 9 in the direction in which the resistor 5 is positioned. The coil spring 33 is in contact with the rear end portion of the held portion 7d of the contact 9, and the contact 9 is housed and compressed in a closed state. The shape of the coil spring 33 is such that the rear end portion of the supported portion 7d of the contact 9 is in contact with the front end portion (lower end portion) of the coil spring 33, and the resistor 5 is connected to the contact 9 from the coil spring 33. It has a shape that can give a force to the side. [0028] In FIGS. 8 (A) and 8 (B) to FIG. 11 (A) and (B), the sliding resistor has an arc shape, and the contactor rotates within a predetermined angular range. FIG. 2 is an exploded perspective view and an assembled perspective view of a rotor portion according to an embodiment in which the present invention is applied to a rotating variable resistor of a moving type. In FIGS. 8A and 8B to 11A and 11B, the same members as those constituting the embodiment shown in FIGS. 1 to 7 are used. The number of codes shown in Fig. 7 plus the number of 200 is added.

FIG. 8A is an exploded perspective view of the rotor portion 202 of the rotary variable resistor, and FIG. 8B is a perspective view showing a state after the rotor portion 202 is assembled. The rotor unit 202 is used when the structure of the linear motion type variable resistor of the first embodiment shown in FIG. 1 is changed to a rotary type variable resistor. In this variable resistor as well, like the variable resistor shown in FIG. 1, a leaf spring 225 is used as a force generating member that constitutes a part of a force applying mechanism 224 that applies a force to the contact 209. In the variable resistor of this example, the arc-shaped resistor 205 shown by a broken line in FIG. 8B is disposed on the surface of the insulating substrate 203, and the rotor portion 202 is disposed on the insulating substrate 203. A storage case (not shown) that rotatably supports the rotor portion with respect to 203 is fixed. A holder 217 integrally formed of an insulating resin material includes a holder body 218 and a rotary shaft 235 provided integrally with the holder body. The holder body 218 is formed with an inclined through hole 223, and the contact 209 is accommodated in the inclined through hole 223 so that the tip end portion is exposed. A through hole 225 a is formed at one end of the leaf spring 225. The fixing member 227 inserted into the through hole 225a is heated and deformed, and one end of the leaf spring 225 is fixed to the holder body 218. The rotating shaft 235 is inserted into a mounting hole provided in a storage case (not shown) and is rotatably supported by the storage case.

FIG. 9 (A) is an exploded perspective view of the rotor portion 202 of another rotary variable resistor, and FIG. 9 (B) is FIG.

FIG. 5 is a perspective view showing a state after assembly of the rotor section 202 shown in FIG. The rotor unit 202 of this example is used when the structure of the linear motion type variable resistor shown in FIG. 5 is changed to a rotary type variable resistor. In order to facilitate understanding, in FIG. 9B, the contact 209 is shown by a solid line. Also in this rotor section 202, a linear spring 229 is used as a force generating member used in the force applying mechanism 224, similarly to the variable resistor shown in FIG. Used. Other structures are the same as those of the embodiment shown in FIG. The linear spring 229 is formed by applying a bending force to the linear spring material. The linear spring 229 includes a curved portion 229a formed by bending a linear spring member into a U shape, and two linear portions 229b extending in parallel from the curved portion 229a. The curved portion 229a includes a locking portion 229c that is bent at a right angle with respect to the linear portion 229b and is folded back at an intermediate portion. The curved portion 29a including the locking portion 229c has a V shape when viewed from the side. The locking portion 229c is locked to a locking structure portion 217c formed on the holder 217. The ends of the two linear portions 229b of the linear spring 229 are also locked to the locking structure portion 217b. The locking structure portion 217b is provided with a locking groove that opens in the lateral direction so that the ends of the two linear portions 229b can enter. The locking structure portion 217c has a structure including a hole portion into which the bending portion 229a is fitted and a locked portion to which the locking portion 229c is locked. By the two linear portions 229b of the linear spring 229 locked to the locking structures 217b and 217c, the end of the held portion 207d of the contact 9 is pressed against the resistor.

FIG. 10 (A) is an exploded perspective view of the rotor portion 202 of another rotary variable resistor, and FIG. 10 (B) shows the assembled state of the rotor portion 202 of FIG. 10 (A). It is a perspective view shown. In order to facilitate understanding, in FIG. 10B, the contact 209 is shown by a solid line. The rotor section 202 is used when the linear motion type variable resistor shown in FIG. 6 is changed from a rotary type variable resistor to a rotary type variable resistor. In the rotor section 202 as well, the torsion spring 231 is used as a force generating member used in the force applying mechanism 224, similarly to the variable resistor shown in FIG. In this example, a spring support protrusion 230 is provided on the side surface of the holder body 218 of the holder 217. A coil portion 231a of a torsion spring 231 is passed through the spring support protrusion 230. One end portion 231c of the torsion spring 231 is fixed to a bulging portion 228 that is integrally provided on the side of the holder main body 218. The other end portion (free end) 231b of the torsion spring 231 is in contact with the rear end portion of the supported portion 207d of the contact 209 while entering the slit 232 formed in the holder body 218. Yes. As a result, the torsion spring 231 applies a downward force to the end of the supported portion 7d of the contact 309 by the other end 23 lb.

FIG. 11A is an exploded perspective view of the rotor portion 202 of another rotary variable resistor. B) is a perspective view showing a state after the rotor part 202 is assembled. In FIG. 11 (B), the contact 209 is shown by a solid line for easy understanding. The rotor unit 202 of this example is a rotor unit used when the structure of the linear motion type variable resistor shown in FIG. 7 is changed to a rotary type variable resistor. Therefore, in this rotor portion 202 as well, the compression coil spring 233 is used as a force generating member material used in the force applying mechanism 224, similarly to the variable resistor shown in FIG.

FIGS. 12A to 12C are partial longitudinal sectional views of still another embodiment of a linear motion type variable resistor according to the present invention. 12 (A) to 12 (C), members similar to those constituting the three embodiments shown in FIG. 1, FIG. 6 and FIG. The number is added with the number of 300 and the description is omitted. In these embodiments, the contact 309 extends in the direction perpendicular to the resistor 305. Accordingly, the through hole or receiving hole 323 that receives the contact 309 extends in the holder body 318 in the vertical direction. In this example, the tip end surface 307f of the contact 309 is entirely in contact with the surface of the resistor 305. Of course, the tip end surface 307f of the contact 309 may be inclined while sliding, and the resistor 305 may be slid on the tip end edge of the inclined tip surface as a contact portion. .

FIG. 13 is a diagram showing a schematic configuration of a main part of still another embodiment in which the present invention is applied to a linear movement type variable resistor. FIGS. 14A and 14B are an exploded perspective view of the contact and holding spring member used in the embodiment of FIG. 13, and an exploded perspective view including the holder. 13 and FIG. 14, members similar to those shown in FIG. 1 to FIG. 7 are given the same reference numerals as those shown in FIG. 1 to FIG. The explanation is omitted. In this example, a force applying mechanism 424 for applying a force to the contact 409, a force holder 417, a holding spring member 420, and the like are configured. The holding spring member 420 includes a base 420a fixed to the holder main body 418, a stagnation part 420b that is provided continuously with the base 420a and extends in an inclined state toward the resistor 405, and a stagnation part 420b. A plate spring member formed by a metal plate cover provided with a contact mounting part 420c to which a contact is mechanically mounted. At the center of each side of the rectangular contact mounting part 420c, there are four force squeezing claw parts 420d. The contact 409 has these four claws 42. Four slits 409a into which Od is fitted are formed. The contact 409 is attached to the contact attachment part 420c by force-squeezing the claw part 420d with the slit 409 fitted in the claw part 420d. In this embodiment, the contact 409 is in contact with the resistor 405 from the vertical direction. As in the embodiment of FIG. 1, it is needless to say that the contact 409 may be attached to the contact attachment part 420c so as to be inclined with respect to the resistor 405. A through hole 420e is formed in the base 420a of the spring member 420. The holder body 418 is provided with a bulging portion 419 that bulges toward the resistor 405 side by force. Further, the facing surface 419a of the bulging portion 419 facing the resistor 405 is inclined, and a fixing portion 427 that can be heated and deformed is formed on the facing surface 419a. The holding spring member 420 is fixed to the bulging portion 419 after the fixing portion 427 is fitted into a through-hole 420e provided in the base portion 420a, and the distal end portion thereof is heated and deformed. In the variable resistor configured as described above, the stagnation portion 420b of the holding spring member 420 is squeezed while the holder 417 and the insulating substrate 403 are housed in a case (not shown). As a result, the amount of stagnation of the stagnation part 420b generates a force that pushes the contactor 409 against the resistor 405.

FIGS. 15A and 15B are exploded perspective views showing different examples of the contact 409 and the holding spring member 420 that can be used for the variable resistor of FIG. 13, and the holder 417 and the contact. FIG. 6 is an exploded perspective view including a holding spring member 420 to which 409 is attached. In this example, two protrusions 420f and one through hole 420g are formed on the contactor mounting portion 420c of the holding spring member 420. A through hole 419 is also formed in the contact 409. The rivet 440 is inserted into the through hole 419 of the contact 409 and the through hole 420g of the contact mounting part 420c, and the tip of the rivet 440 is crushed to contact the contact 409. Attach to the child mounting part 420c. The protrusion 420f engages with the edge of the contact 409 to exert a detent function.

FIGS. 16 (A) and 16 (B) are exploded perspective views showing different mounting states of another contact 409 and holding spring member 420 that can be used in the variable resistor of FIG. FIG. 5 is an exploded perspective view including a holding spring member 420 to which a child 409 is attached. In this example, the holding mechanism for holding the contact 409 between the two plate-like portions 420h and 420i is formed by bending the contact mounting portion of the holding spring member 420 in an inverted U shape. One plate-like part 420h has the other plate A projecting protrusion 420j is formed so as to protrude from the ridge 420 to a force. The contact 409 is formed with a through hole 419 into which the projecting protrusion 420j is fitted. In this example, the contact 409 is sandwiched between the two plate-like portions 420h and 420i, and the projecting projection 420j is fitted into the through hole 419 so as to prevent slipping and rotation.

FIG. 17A is a perspective view showing still another example of a holding spring member 520 using a leaf spring. FIG. 17B shows a contact 519 attached to the holding spring member 520. FIG. 17C is an exploded perspective view for explaining the case of attachment, and FIG. 17C is a perspective view of a state in which the contact 519 is attached to the holding spring member 520. In this example, one end of the holding spring member 520 is provided with a notch 520m used when being fixed to a holder (not shown). The holding spring member 520 has a slit 520η at the center, and two through holes 520k at the other end so as to sandwich the slit 520η. Further, the contact 509 is formed with two through holes 519 aligned with the two through holes 520k provided in the spring member 520 in the held portion 507d. The spring member 520 and the contact 509 are coupled by passing the rivet 540 through the aligned through hole 519 and through hole 520k and deforming the tip of the rivet 540.

FIG. 17 (A) is a perspective view showing still another example of a holding spring member 520 using a leaf spring. FIG. 17 (B) shows a contact 519 attached to the holding spring member 520. FIG. 17C is an exploded perspective view for explaining a case of attachment, and FIG. 17C is a perspective view of a state in which a contact 509 is attached to a holding spring member 520. In this example, one end of the holding spring member 520 is provided with a notch 520m used when being fixed to a holder (not shown). The holding spring member 520 has a slit 520η at the center, and two through holes 520k at the other end so as to sandwich the slit 520η. Further, the contact 509 is formed with two through holes 519 aligned with the two through holes 520k provided in the spring member 520 in the held portion 507d. The spring member 520 and the contact 509 are coupled by passing the rivet 540 through the aligned through hole 519 and through hole 520k and deforming the tip of the rivet 540.

FIG. 18 (A) is a perspective view showing still another example of a holding spring member 620 using a leaf spring. FIG. 18 (B) shows a contact 509 attached to the holding spring member 620. When installing FIG. 18C is a perspective view of a state in which a contact 519 is attached to a holding spring member 620. FIG. In these figures, for the holding spring member 620, a number of 100 is added to the numeral in FIG. 17 (A) in the same manner as the spring member 520 shown in FIG. 17 (A). A number sign is attached and explanation is omitted. In this example, two cylindrical portions 620p are provided at the other end of the holding spring member 620 so as to sandwich the slit 520η. The spring member 620 and the contact 509 are coupled by curling the tip of the cylindrical part 620p after inserting the cylindrical part 620p into the through hole 519.

FIGS. 19A to 19C show perspective views of examples in which the holding spring member is constituted by a spring wire, respectively. The structure of the holding spring members 720, 820, 920 may be any structure not limited to the above example.

Industrial applicability

[0041] In the variable resistor of the present invention, the contact including the carbon fiber has a rigidity that does not squeeze when performing a sliding operation, so that the contact portion is always in a stable state. Can be brought into contact with the resistor. In particular, in the present invention, the holder is provided with a force applying mechanism for applying to the contact a force for pressing the contact portion of the contact against the surface of the resistor. Therefore, the contact can be pressed against the resistor with an appropriate biasing force according to the shape and rigidity of the contact. As a result, even if the contact portion of the contact begins to wear, the contact resistance between the contact portion and the surface of the resistor does not change extremely. Further, there is no gap between the contact portion and the resistor so that abrasion powder or the like enters. Furthermore, there is an advantage that the contact portion of the contact including carbon fibers can be pressed against the surface of the resistor with a pressing force within a proper range over a long period.

Claims

The scope of the claims

[1] a resistor provided on the surface of the insulating substrate;

A contact having a contact portion that slides on the surface of the resistor at the tip, and a held portion at a position opposite to the tip;

A holder that is operated when holding the contact directly or indirectly and sliding the contact portion on the surface of the resistor;

A force applying mechanism configured to be provided separately from the contact and provided in the holder, and to apply a force to the contact to press the contact portion of the contact against the surface of the resistor;

The contact is configured to obtain electrical conductivity using carbon fiber and synthetic resin as main raw materials, and the contact has the contact portion sliding on the surface of the resistor, A variable resistor characterized by having rigidity that does not linger.

[2] The contact includes a held portion on the opposite side of the tip,

The holder has a holder main body, and the holder main body is formed with a receiving hole that opens toward the insulating substrate and slidably receives the held portion of the contact.

The force applying mechanism applies a force to the held portion of the contact in a state in which the held portion of the contact is received in the receiving hole, and directs the contact portion toward the surface of the resistor. The variable resistor according to claim 1, wherein the variable resistor is configured to be pressed.

[3] The variable resistor according to [2], wherein the receiving hole extends obliquely with respect to a surface of the resistor.

[4] The force applying mechanism includes a spring member arranged to generate a pressing force that presses the contact portion against the surface of the resistor against a rear end portion of the held portion of the contact. The variable resistor according to claim 2 provided.

[5] The contact includes a held portion on the opposite side of the tip,

The holder has a holder body;

The force applying mechanism includes a base fixed to the holder main body and a base that is continuous with the base. A squeeze portion extending in a tilted state against the resistor, and a contact attachment portion provided continuously with the squeeze portion and mechanically attached to the held portion of the contact. The variable resistance according to claim 1, wherein the structure of the contactor mounting portion is a fitting structure, a caulking structure, or a sandwiching structure, and the held portion of the contactor is held by a spring member force having a contactor mounting function. The variable resistor according to claim 5, wherein the variable resistor is configured to be mechanically held.