JP5048665B2 - Variable resistor - Google Patents

Description

  The present invention relates to a variable resistor in which a contact portion at the tip of one or more contact pieces is slid while being brought into contact with the surface of a resistor.

  This type of variable resistor is generally used not only for the purpose of exerting a variable resistance function, but also for replacing mechanical displacement such as a rotation angle and a moving distance with electrical information in an automobile or a production machine. Conventionally, it has been widely used as a so-called position detection sensor. For example, the variable resistor is used for the purpose of taking out a position signal corresponding to the stepping angle of an accelerator of an automobile as an electric signal. When using a variable resistor as the variable resistance type position detection sensor, in order to increase the position detection accuracy, it is important to make the contact portion provided at the tip of the contact piece as narrow as possible in the moving direction. If the area of the contact portion provided at the tip of the contactor is large, the electrical contact position between the resistor and the contact portion varies during sliding, which causes hysteresis of the output signal. Such a contact may be required to have three characteristics: a spring property for applying a pressure to the contact, a sliding characteristic that slides on the resistor, and an electric conduction characteristic. In the variable resistor used for such an application, the contact is repeatedly slid on the resistor repeatedly.

  Early variable resistor contact pieces used in such applications were made of metal. However, when the metal contact is repeatedly slid on the resistor, the difference between the hardness of the metal and the resistance of the resistor causes the resistor to wear until the variable resistor becomes unusable ( There was a problem that the time until the end of the service life was short. In addition, when a conventional metal contact is used, a large amount of wear powder is generated until the end of its life. The wear powder enters the gap between the contact portion of the contact and the resistor, making the electrical contact unstable and causing sliding noise.

  Therefore, it has been proposed to form a contact by processing one or more prepregs formed into a plate shape by impregnating a bundle of many carbon fibers with a thermosetting conductive insulating resin (for example, (See Patent Document 1). This contact 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, the tip of one or more contact pieces is bent into a chevron or bent at 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.

  Further, in the contact shown in Patent Document 2, a bundle 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 in line contact with the surface of the resistor. Or surface contact.

In the conventional variable resistor using such a carbon fiber, since the contact has a structure in which a large number of carbon fibers are hardened with a thermosetting resin, there is an advantage that the wear is reduced and the life is extended. Moreover, such a variable resistor has an advantage that the generation of wear powder is remarkably reduced.
Japanese Patent Application Laid-Open No. 2003-51361 FIG. Japanese Patent Application Laid-Open No. 2004-31688

  However, in the former variable resistor having the conventional structure, the free end of the contact piece is bent at a right angle, and the end face of the bent tip is brought into surface contact with the surface of the resistor. Therefore, when sliding on the surface of the resistor so that the bent portion is facing forward, the portion after the bent portion of the contact piece bends due to the frictional resistance with the sliding resistance. When the deflection reaches the limit, a so-called stick-slip motion, which is a phenomenon in which the bent portion jumps from the surface of the resistor and jumps forward in order to return to the original shape, may occur. When such a movement occurs, there arises a problem that the resistance value changes.

  In the variable resistor having the latter structure, the side surface facing the surface of the resistor on the tip side of the contact piece is brought into surface contact with the surface of the resistor. For this reason, there is a problem that a true contact point (a point where contact is made so that current flows) generated in the contact area fluctuates in the contact surface, and the position of the electrical conduction point at the time of sliding cannot be determined.

  An object of the present invention is to provide a variable resistor in which a contact is formed using carbon fibers and the above-described problems do not occur.

  Another object of the present invention is that the contact portion of the contact piece jumps and the resistance value does not change inadvertently, and electrical conduction to the resistor of the contact portion can be ensured to improve the position detection capability. The object is to provide a variable resistor that can be used.

  Still another object of the present invention is to provide a variable resistor capable of smoothly sliding a contact portion.

  The variable resistor according to the present invention includes a resistor provided on the surface of an insulating substrate, a contact composed mainly of carbon fiber and synthetic resin so as to obtain conductivity, and a holder for holding the contact And have. The holder may be directly attached to the insulating substrate to be movable, or may be attached to the case fixed to the insulating substrate to be movable. The contact includes one or more contact pieces having a tip portion provided with a contact portion that slides on the surface of the resistor, and a held portion located on the opposite side of the contact portion. The holder holds the held portion of the contact so that the contact portion of one or more contact pieces comes into contact with the surface of the resistor.

  Any configuration may be used as long as the required electrical conductivity and mechanical strength (rigidity) can be obtained when the contact is formed of carbon fiber and synthetic resin as main raw materials. For example, the contacts may be integrally formed with a carbon fiber mixed resin in which carbon fiber chips are randomly mixed so as to obtain conductivity. In addition, a woven fabric or nonwoven fabric is made using a large number of carbon fibers, and a prepreg is made by impregnating the woven fabric or nonwoven fabric with a thermosetting insulating resin to make thermosetting of one or more prepregs. You may make it make a contactor using the carbon fiber sheet which heat-cured resin. When using a plurality of prepregs, a plurality of prepregs using a woven fabric or a nonwoven fabric may be stacked, or a plurality of prepregs using a woven fabric and a prepreg using a nonwoven fabric may be mixed and stacked. Further, a carbon fiber sheet for constituting a contact may be created by sandwiching one or more prepregs of woven or non-woven fabric between two prepregs made of only resin. 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. Further, when the contact is formed by integral molding, the carbon fiber may be exposed by cutting the portion corresponding to the contact portion or the like.

  The carbon fiber sheet is formed by laminating a plurality of prepregs having a structure in which a plurality of carbon fibers are arranged in one direction, and the plurality of laminated prepregs are alternately arranged in a direction in which a plurality of carbon fibers are arranged. If the layers are laminated so as to be different from each other, the rigidity is increased and the creep deformation becomes difficult. Therefore, desired rigidity or flexibility can be obtained by appropriately changing the number of prepregs to be laminated.

  In the variable resistor according to the present invention, one or more contact pieces of the contact have a front end surface extending in a direction intersecting with the direction from the front end toward the held portion. Then, a contact portion is constituted by a corner portion formed between the side surface continuous with the tip surface and facing the resistor and the tip surface. From another viewpoint, the contact has rigidity (or flexibility) that only the corner portion becomes a contact portion and the side surface does not become a contact point. In addition, the side surface of the one or more contact pieces facing the resistor is not in contact with the surface of the resistor, only the corner portion is in contact with the surface of the resistor, and the side facing the resistor is the side of the resistor. It has a structure for holding the held portion of the contact so as to be inclined with respect to the surface.

  When the contact is configured in this way and the holder is configured to hold the held portion of the contact so that the side surface of the contact facing the resistor is inclined with respect to the surface of the resistor, One or more contact pieces come into contact with the surface of the resistor only at the corner. This contact is a line contact when viewed macroscopically, and the contact area is extremely small. As a result, the contact stress at the contact portion becomes very high, and the corner portion becomes a very good sliding contact. Moreover, since the carbon fiber is contained in the contactor, sliding can be performed smoothly by the lubricating action of the carbon fiber. When the contact is smoothly slid, the contact portion jumps from the surface of the resistor and the resistance value does not change carelessly. As a result, electrical conduction to the resistor at the contact portion can be ensured, and the position detection capability can be improved. Furthermore, in a variable resistor in which the contact is inclined with respect to the resistor and only the contact portion consisting of the corner portion is in contact with the resistor, the contact portion is a deposit such as wear powder during sliding, etc. Can be removed from the resistor. Therefore, the contact between the contact portion and the resistor does not become unstable due to the presence of the deposit.

  The structure of the holder that holds the contact is arbitrary. For example, the holder may have a structure including a holder main body having an operation unit and a contact holding unit that holds the contact, and the held portion of the contact may be directly held by the contact holding unit. . As described above, the holder may be directly supported by the insulating substrate, but may be supported by a case fixed to the insulating substrate.

  The contactor holding portion of the holder may have a structure having conductivity and springiness. In this case, the held part of the contactor may be mechanically held by the contactor holding part, and the held part of the contactor and the contactor holding part of the holder may be electrically connected. With such a structure, the size of the contact can be reduced, and the required mechanical strength can be obtained at the contact holding portion of the holder, and the contact can be made a resistor with respect to the contact holding portion. It is also possible to provide a function for generating a pressing force against the robot.

  The contactor structure includes one or more contact pieces having a tip portion having a contact portion, a base portion constituting a part of the held portion, and a flexure portion positioned between the tip portion and the base portion. It is good also as a structure. With such a structure, the force of pressing the contact portion against the resistor can be generated by the spring property of the bent portion of the contact. The spring property (rigidity) of the bent portion is a spring property (rigidity) such that only the contact portion contacts the surface of the resistor and the bent portion does not contact the surface of the resistor. In this case, the aforementioned corner portion is located in a region surrounded by a tangential plane with respect to the tip end surface of the contact and a tangential plane with respect to the bending portion (side surface of the contact piece).

  If the holder is embedded and supported so that the surface facing the resistor of the contact is inclined with respect to the surface of the resistor, the structure for supporting the contact of the holder is very simple. become.

  Further, the holder may be provided with an inclined surface that supports the held portion so that the bending portion of the contact is inclined with respect to the surface of the resistor, and a fixing portion that fixes the base of the contact is provided on the inclined surface. Good.

  In the case of using a plurality of contact pieces arranged at a predetermined interval in the width direction of the resistor, the inclination angle between the tangent plane of the bending portion of the plurality of contact pieces and the surface of the resistor is 10 It is preferable that the angle be in the range of degrees to 85 degrees. If it does in this way, a contact part can be slid smoothly. When the inclination angle is smaller than 10 degrees, the contact portion is close to surface contact. For this reason, unless the contact hardness is very high (the rigidity is considerably high), the true contact point will fluctuate in the contact area during sliding, and the electrical conduction point position during sliding will not be determined. To do. Further, even when the inclination angle is larger than 85 degrees, unless the hardness of the contactor is considerably high, the contact portion of the contact piece easily jumps and slides during sliding, which is not preferable.

  The carbon fiber sheet preferably has the following internal structure. That is, a plurality of prepregs having a structure in which a plurality of carbon fibers are arranged in one direction are laminated. The plurality of laminated prepregs are laminated so that the directions in which the plurality of carbon fibers are arranged alternately are different. When the carbon fiber sheet having such a structure is used, rigidity is increased (flexibility is reduced), and one or more contact pieces are hardly creep-deformed.

  The contactor may be provided with a backup leaf spring on the surface opposite to the surface facing the resistor. The backup leaf spring may be supported by the holder. When the backup leaf spring is attached to the contact, the desired rigidity or flexibility can be realized even when the contact has low rigidity.

It is a side view which shows an example of the best form for implementing the variable resistor which concerns on this invention. It is a perspective view of the contactor used with the variable resistor of FIG. FIG. 3 is an enlarged cross-sectional view along line AA in FIG. It is an enlarged view of the edge part of the contact piece used with the variable resistor of FIG. It is the side view which showed the principal part of the 2nd example of embodiment of the variable resistor of this invention. It is the side view which showed the principal part of the 3rd example of embodiment of the variable resistor of this invention. It is the side view which showed the principal part of the 4th example of embodiment of the variable resistor of this invention.

  Hereinafter, a first example of the best mode for carrying out a variable resistor according to the present invention will be described in detail with reference to FIGS. 1 is a side view of the configuration of the main part excluding the case of the variable resistor of this example, FIG. 2 is a perspective view of a contact used in the variable resistor of this example, and FIG. 3 is an AA of FIG. FIG. 4 is an enlarged schematic cross-sectional view of a corner portion of a contact piece of a contact used in the variable resistor of this example.

  The variable resistor of this example is a type of variable resistor in which the resistor is linear and the contact is linearly slid on the resistor. As shown in FIG. 1, in the variable resistor 1 of this example, 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 of this example is formed by printing a resistor pattern on the insulating substrate 3 using a resistor paste and then firing the resistor pattern. The resistor 5 may be formed by firing without causing the resistor paste to dry naturally, or may be formed by cutting a resin electrical resistance film and pasting it on a substrate. Good.

  On the surface of the resistor 5, a contact 9 in which the contact portions 7 s at the tips of the two contact pieces 7 are in contact is disposed. The contactor 9 is formed by subjecting a carbon fiber sheet formed using carbon fibers 11 and a synthetic resin as main raw materials to a cutting process or the like. The contact 9 includes a tip 7a having a contact 7s that slides on the surface of the resistor 5, a base 7b1 that constitutes a part of the held portion 7b, and a tip 7a and a base 7b1. Two contact pieces 7 each having a bending portion 7c located are provided. The contact 9 of this example includes two contact pieces 7 and has a structure in which the base portions 7b1 of the two contact pieces 7 are connected by a connecting portion 7d.

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

  As described above, the carbon fiber sheet used in this example is configured by laminating three prepregs 15 having a structure in which a plurality of carbon fibers 11 are arranged in one direction. The prepregs 15 made of three carbon fiber sheets are laminated and integrated so that the direction in which the plurality of carbon fibers 11 are arranged alternately is different. That is, this carbon fiber sheet has a prepreg in which the carbon fiber 11 is oriented in a direction perpendicular to the longitudinal direction of the contact piece 7 between the two prepregs 15 in which the carbon fiber 11 is oriented in the longitudinal direction of the contact piece 7. It is the structure which integrated 15 sheets. 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 a carbon fiber mixed resin in which short chips of carbon fiber chips are randomly mixed. In addition, a woven fabric or nonwoven fabric is made using a large number of carbon fibers, and a prepreg is made by impregnating the woven fabric or nonwoven fabric with a thermosetting insulating resin to make thermosetting of one or more prepregs. You may make it make a contactor using the carbon fiber sheet which heat-cured resin. When using a plurality of prepregs, a plurality of prepregs using a woven fabric or a nonwoven fabric may be stacked, or a plurality of prepregs using a woven fabric and a prepreg using a nonwoven fabric may be stacked. Further, a carbon fiber sheet for constituting a contact may be created by sandwiching one or more prepregs of woven or non-woven fabric between two prepregs made of only resin. And when forming a contactor from such a carbon fiber sheet by a cutting process, a cut surface comprises a contact part. In this way, since the carbon fiber is always exposed on the cut surface, the electrical conductivity of the contact portion can be ensured. Further, when the contact is formed by integral molding, the carbon fiber may be exposed by cutting the portion corresponding to the contact portion or the like.

  The one or more contact pieces 7 have a cut surface extending in a direction intersecting with the direction from the tip portion 7a toward the base portion 7b1 as the tip surface 7f. Then, a corner portion 7k formed between the front end surface 7f and the side surface 7g of the bent portion 7c (or between the front end surface 7f and the side surface 7g opposed to the surface of the resistor 5 of the bent portion 7c). Constitutes the contact portion 7s. The corner portion 7k is located in a region surrounded by a tangential plane 7ff with respect to the distal end surface 7f and a tangential plane 7cf with respect to the bent portion 7c (tangent plane with respect to the side surface of the bent portion 7c at a position close to the distal end surface 7f).

  Such a contact 9 is held by a holder 17. The holder 17 includes a holder main body 17a to be operated and a contact holder holding portion 17b provided on the holder main body 17a. The contactor holding portion 17b of the holder 17 used in this embodiment has a vertical cross-sectional shape of a right triangle, and the inclined surface 17c faces the surface of the insulating substrate 3. The holder 17 holds the contact 9 so that the tips 7 a of the two contact pieces 7 are brought into contact with the surface of the resistor 5 and a space is provided between the bent portion 7 c and the surface of the resistor 5. The part 7 b is held in a fixed state by the fixing part 19. In the present embodiment, since the holder is formed of synthetic resin, the fixing portion 19 is also configured as a protrusion of synthetic resin. And the fixing | fixed part 19 which consists of this protrusion is fitted to the through-hole 7h provided in the to-be-held part 7b of the contactor 9. FIG. Thereafter, the held portion 7b is held by the contact holding portion 17b by deforming the tip of the fixing portion 19 so as to be crushed by welding. Of course, a screw or the like may be used as the fixing member. The number of the fixing portions 19 and the through holes 7h may be plural.

  The inclination angle of the inclined surface 17 c provided on the contact holder holding portion 17 b of the holder 17 is such that the side surface 7 g of the bending portion 7 c of the two contact pieces 7 is the surface of the resistor 5 in consideration of the rigidity of the contact 9. Only the corner portion 7k of the two contact pieces 7 is in contact with the surface of the resistor 5, and the bent portion 7c is inclined with respect to the surface of the resistor 5. 7b is held. If the rigidity of the contact is high to some extent, the inclination angle α between the tangent plane 7cf of the flexure 7c of the two contact pieces 7 and the surface of the resistor 5 is in the range of 10 degrees to 85 degrees. It is preferable to determine the inclination angle of the inclined surface 17c. It should be noted that the distance between the insulating substrate 3 and the holder 17 is such that the bending portion 7c of the two contact pieces 7 does not contact the surface of the resistor 5, and only the corner portion 7k of the two contact pieces 7 is resistant. Of course, it is determined to be in contact with the surface of the body 5. The distance between the insulating substrate 3 and the holder 17 is maintained at a constant value due to the presence of a case (not shown) fixed to the insulating substrate 3 and slidably supporting the holder 17. In addition, the structure of the case which supports the holder 17 so that a slide is possible should just employ | adopt a well-known structure, and is arbitrary.

  In the variable resistor 1 of this example, the contactor 9 is formed by cutting so as to form two contactor pieces 7 on the carbon fiber sheet. And the two contact piece 7 has the cut surface extended in the direction which cross | intersects the direction which goes to the base 7b1 from the front-end | tip part 7a as the front end surface 7f. The corner portion 7k formed between the tip surface 7f and the bent portion 7c constitutes the contact portion 7s. As a result, the carbon fiber is exposed at the corner portion 7k of the two contact pieces 7. The exposed cut surface of the carbon fiber contacts the surface of the resistor 5. The contact at the corner portion 7k is a line contact, and the contact area is extremely small. Therefore, the contact stress at the contact portion 7s, which is determined by the distance between the holder 17 and the insulating substrate 3, the inclination angle of the contact 9, the rigidity of the contact, etc. becomes very high, and an extremely good sliding contact can be obtained. When the corner portion 7k is a sliding contact point, the contact portion 7s does not jump from the surface of the resistor 5, and the resistance value does not change carelessly. Moreover, the real contact area with respect to the surface of the resistor 5 becomes very large. Therefore, each contact piece 7 of the contact 9 of the variable resistor 1 has a very good sliding contact point.

  When such a contact piece 7 is repeatedly used, as shown in FIG. 4, the contact portion 7s is worn down and a chamfered portion 7m is formed. As long as the area of the chamfered portion 7m serving as the contact portion 7s falls within a predetermined value range, the contact piece 7 can be used without any trouble.

  Even if the surface of the resistor 5 is worn and powder is generated, there is no problem because the powder is collected and hardened in the sliding direction by the sliding of the contact portion 7s according to experiments.

  In the above example, the contact 9 has a structure having two contact pieces 7. However, the contact piece 9 may have one or more contact pieces 7 and the number of the contact pieces 7 is particularly limited. It is not something.

  FIG. 5 is a side view showing the configuration of the main part of the second example of the embodiment of the variable resistor of the present invention. In addition, the same code | symbol is attached | subjected to the part corresponding to the 1st example mentioned above, and description is abbreviate | omitted. The variable resistor of this example also shows a type in which the resistor is linear and the contact is reciprocated linearly. In the variable resistor of this example, the contact 9 is arranged such that a backup leaf spring 21 is attached to the side surface opposite to the side surface 7 g facing the resistor 5. The backup leaf spring 21 is supported by the holder 17. Other configurations are the same as those of the first example described above.

  When the contact 9 is backed up by the backup leaf spring 21 in this way, even if the contact has low rigidity or flexibility, the backup leaf spring 21 reinforces the rigidity or flexibility of the contact 9. be able to.

  FIG. 6 is a side view showing the configuration of the main part of the third example of the embodiment of the variable resistor of the present invention. In addition, the same code | symbol is attached | subjected to the part corresponding to the 1st example mentioned above, and description is abbreviate | omitted. In the variable resistor of this example, in the holder 17, the held portion 7 b of the contact 9 is integrally embedded so that the surface 7 g facing the resistor 5 of the contact 9 is inclined with respect to the surface of the resistor 5. It is supported. Other configurations are the same as those of the first example described above. If it is such a structure, the structure which supports the contactor 9 of the holder 17 will become very simple.

  FIG. 7 is a diagram showing the configuration of the main part of the embodiment of the variable resistor of the present invention. In addition, the same code | symbol is attached | subjected to the part corresponding to the 1st example mentioned above, and description is abbreviate | omitted. In this example, the contact holder holding portion 17b of the holder 17 has a structure including a metallic leaf spring portion 17d having conductivity and spring property. The leaf spring portion 17d is arranged along the inclined surface 17c and fixed to the contact surface, a base portion 17e that is continuous with the base portion 17e, bent by an external force, and a holding portion provided at the tip of the bent portion 17f. 17g. The inclination angle of the holding portion 17g is larger than the inclination angle of the bending portion 17f. The contact 9 ′ held by the holding portion 17g is arranged in an inclined state with respect to the surface of the resistor 5. As a result, the corner portion 7 ′ k of the contact piece 7 ′ of the contact 9 becomes a contact portion and slides on the resistor 5. The contact 9 'and the holding portion 17g of the spring portion 17d are coupled by a mechanical coupling structure such as a caulking structure or a clamping structure. In order to ensure the electrical connection between the holding portion 17g and the contact 9 ', the surface of the contact 9' that is in contact with the holding portion 17g is previously covered with a synthetic resin. Cutting or polishing for exposing the carbon fibers is performed. If such processing is performed, the electrical connection between the two is ensured.

  In the above embodiment, the present invention is applied to a variable resistor in which the contact linearly slides on the resistor. However, in the present invention, the contact slides on the arc-shaped resistor. Of course, the present invention can also be applied to a rotating variable resistor that moves.

  According to the variable resistor according to the present invention, since one or more contact pieces come into contact with the surface of the resistor only at the corner portion, an extremely good sliding contact can be obtained. And since the contact piece is a sliding contact point where the contact is made at the corner portion, and the sliding is performed smoothly, the contact portion jumps from the surface of the resistor and the resistance value may change carelessly. This eliminates the advantage that electrical conduction to the resistor at the contact portion can be ensured. As a result, the position detection capability can be improved.

  Furthermore, in the variable resistor of the present invention in which the contact is inclined and only the contact portion is in contact with the resistor, accumulated foreign matter such as wear powder can be removed from the resistor during sliding. In addition, there is an advantage that the contact between the contact portion and the resistor does not become unstable due to the deposit on the resistor.

Claims (15)

A resistor provided on the surface of the insulating substrate;
One or more contact pieces and held parts, which are composed of carbon fiber and synthetic resin as main raw materials so as to obtain conductivity and have a tip part having a contact part that slides on the surface of the resistor. A contactor with
A holder for holding the contact so that the contact portion of the one or more contact pieces contacts the surface of the resistor;
The one or more contact pieces have a tip surface extending in a direction intersecting with a direction from the tip portion toward the held portion at the tip portion, and are continuous with the tip surface and face the resistor. A corner portion formed between a side surface and the front end surface is configured to constitute the contact portion;
In the holder, the side surface of the one or more contact pieces does not contact the surface of the resistor, only the corner portion contacts the surface of the resistor, and the side surface of the surface of the resistor. A variable resistor having a structure for holding the held portion of the contact so as to be inclined with respect to the contact.   When the contact portion slides on the surface of the resistor while the contact is held by the holder, only the corner portion contacts the surface of the resistor, and the side surface is The variable resistor according to claim 1, wherein the variable resistor has rigidity that does not contact the surface of the resistor.   A backup leaf spring is disposed along a surface of the contact opposite to the surface facing the resistor, and the backup leaf spring is supported by the holder. Item 2. The variable resistor according to Item 1.   The variable resistor according to claim 1, wherein the corner portion is located in a region surrounded by a tangential plane with respect to the tip end surface and a tangential plane with respect to the side surface.   The contactor is formed by cutting or polishing a plate material formed using a carbon fiber mixed resin obtained by kneading the carbon fiber chip in a synthetic resin as a main raw material, and the tip surface is a cut surface or The variable resistor according to claim 1, wherein the variable resistor is formed by a processed surface.   The contactor is formed by cutting or polishing a plate material formed using one or more prepregs formed by impregnating the synthetic resin into the carbon fiber woven or nonwoven fabric, The variable resistor according to claim 1, wherein the front end surface is constituted by a cut surface or a polished surface. The holder includes a holder main body provided with an operation part, and a contact holding part for holding the contact.
The variable resistor according to claim 1, wherein the held portion of the contact is directly held by the contact holding portion. The holder includes a holder main body provided with an operation part, and a contact holding part for holding the contact.
The contact holding part has a structure having conductivity and spring property,
The variable resistor according to claim 1, wherein the held portion of the contact is mechanically held by the contact holding portion, and the held portion and the contact holding portion are electrically connected. The resistor is linearly provided on the surface of the insulating substrate,
2. The holder according to claim 1, wherein the contact portion of the contact is in contact with the surface of the linear resistor and can slide back and forth in the longitudinal direction of the resistor. The variable resistor described in 1.   The resistor is arranged in an arc shape on the surface of the insulating substrate, and the holder is configured to slide the contactor along the resistor with the contact portion contacting the resistor. The variable resistor according to claim 1. A resistor provided on the surface of the insulating substrate;
Carbon fiber and synthetic resin as main components so as to obtain conductivity, a tip portion having a contact portion that slides on the surface of the resistor, and a base portion constituting a part of the held portion A contactor provided with one or more contactor pieces provided with a bending part located between the tip part and the base part;
The tip of the one or more contact pieces is brought into contact with the surface of the resistor, and the held portion of the contact is held so as to leave a gap between the bent portion and the surface of the resistor. A holder,
The one or more contact pieces have a front end surface extending in a direction intersecting with a direction from the front end portion toward the base portion, and a corner portion formed between the front end surface and the bending portion. Constitutes the contact portion,
In the holder, only the corner portion of the one or more contact pieces is in contact with the surface of the resistor without the bending portion being in contact with the surface of the resistor, and the bending portion is brought into contact with the surface of the resistor. A variable resistor, characterized by having a structure for holding it so as to be inclined.   11. The held portion is integrally embedded and supported in the holder so that a surface of the contact element facing the resistor is inclined with respect to the surface of the resistor. The variable resistor described.   The holder is provided with an inclined surface that supports the held portion so that the bent portion of the contact is inclined with respect to the surface of the resistor, and the base of the contact is fixed to the inclined surface. The variable resistor according to claim 11, wherein a fixed portion is provided. A plurality of the contact pieces are arranged at predetermined intervals in the width direction of the resistor,
The inclination angle between the tangent plane of the bending portion of the plurality of contact pieces and the surface of the resistor is an angle in a range of 10 degrees to 85 degrees. Variable resistor.   The variable resistor according to claim 11, wherein the corner portion is located in a region surrounded by a tangential plane with respect to the tip end surface and a tangential plane with respect to the bent portion.

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