JP2016021438A - Variable capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent foreign matters from intruding between a rotor and a stator.SOLUTION: A rotor (21) of a variable capacitor (1) includes: a rotor electrode part (24); a non-electrode part (25) that is thin and is not in contact with a stator (31); and a hole (23) for inserting a driver (7). The stator (31) has a recess part (33), having an area larger than that of the hole (23), communicating with the hole (23) at a placement surface of the rotor (21).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a variable capacitor having a variable capacitance.

  A conventional variable capacitor disclosed in Patent Document 1 will be described with reference to FIGS. As shown in FIG. 13, the variable capacitor 101 includes a frame 112, a rotor 121, and a stator 131. The rotor 121 is placed on the top surface of the stator 131. The frame 112 covers each of the rotor 121 and the stator 131.

  As shown in FIG. 13 and FIG. 14, the rotor 121 has a rotor electrode portion 124 on one half of one side and having a large thickness, and a rotor electrode 122 disposed on the other side, and is thicker than the rotor electrode portion 124 on the other half. The non-electrode portion 125 is thin and has no rotor electrode, and the rib 126 extends from the surface of the non-electrode portion 125 facing the stator 131 toward the top surface of the stator 131. In the rotor 121, the surfaces of the rotor electrode portion 124 and the rib 126 facing the stator 131 are in contact with the top surface of the stator 131, and the surface of the non-electrode portion 125 facing the stator 131 is the top surface of the stator 131. Separated from the surface.

  A hole 123 for inserting the driver 107 is formed in the central portion of the rotor 121. The corners of the driver 107 come into contact with the corners of the hole 123 that is a square, and the rotor 121 is rotated by rotating the driver 107. Thereby, the position of the rotor 121 in the rotational direction can be adjusted.

  As shown in FIGS. 13 and 15, the stator 131 includes a stator electrode 132 and a body 134. The stator electrode 132 is disposed inside the body 134.

  As shown in FIG. 13, the vicinity of the hole 123 of the rotor 121 in the frame 112 is a portion where the frame 112 is bent toward the rotor 121. The bent portion is in contact with the top surface of the rotor 121 and functions as a spring that presses the rotor 121 against the stator 131.

Japanese Patent Laid-Open No. 10-321467 (released on December 4, 1998)

  As shown in FIG. 13, the hole 123 of the rotor 121 is formed through the rotor 121. For this reason, as shown by the arrow Z1, when the driver 107 having the foreign substance 109 attached to the tip is inserted into the hole 123, the foreign substance 109 is inserted into the non-electrode portion 125 and the stator 131 of the rotor 121 through the hole 123. It will be in the gap with the top of the.

  Further, the frame 112 is not covered in the vicinity of the gap between the non-electrode portion 125 of the rotor 121 and the top surface of the stator 131, and the gap between the non-electrode portion 125 of the rotor 121 and the top surface of the stator 131 is open. . As shown by the arrow Z2, the foreign substance 109 enters the gap between the non-electrode portion 125 of the rotor 121 and the top surface of the stator 131 through the opening.

  When the rotor 121 is rotated with the foreign matter 109 in the gap between the non-electrode portion 125 of the rotor 121 and the top surface of the stator 131, the foreign matter 109 is brought into contact with the lower surface of the rotor electrode portion 124 and the top surface of the stator 131. I bite in between. As described above, when the foreign matter 109 is caught between the lower surface of the rotor electrode portion 124 and the top surface of the stator 131, the electrostatic capacitance is suddenly changed.

  Note that the rotor 121 is not fixed to the stator 131 by a rotating shaft or the like, but is only pressed against the stator 131 from the top surface side by the frame 112. For this reason, the rotor 121 is eccentric with respect to the stator 131 when rotated by the driver 107 inserted into the hole 123.

  A plurality of circles indicated by arrows R in FIG. 15 represent the rotation trajectory of the rotor 121. Thus, the position of the rotating shaft of the rotor 121 is not constant but deviates. According to the variable capacitor 101, the capacity deviation is caused by the eccentricity of the rotor 121.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a variable capacitor in which foreign matter is prevented from entering between the rotor and the stator.

  In order to solve the above problems, a variable capacitor according to an aspect of the present invention includes a stator on which a stator electrode is disposed, and a rotor placed on the stator, and the rotor is thick. A rotor electrode portion on which a rotor electrode is disposed, a non-electrode portion that is thinner than the rotor electrode portion and is not in contact with the stator, and a through hole. The stator is mounted on the rotor. The placed mounting surface has a recess communicating with the through hole.

  According to one aspect of the present invention, there is an effect that foreign matter is prevented from entering between the rotor and the stator.

2 is a cross-sectional view of a variable capacitor according to Embodiment 1. FIG. 2 is a perspective view of a variable capacitor according to Embodiment 1. FIG. FIG. 3 is an exploded perspective view of the variable capacitor according to the first embodiment. (A) is the bottom view of the rotor which the variable capacitor which concerns on Embodiment 1 has, (b) is the perspective view seen from the lower surface side of the rotor shown to (a). FIG. 3 is a top view of a stator included in the variable capacitor according to the first embodiment. (A) is a perspective view which shows the rotation locus part of the rotor electrode cut out from the variable capacitor based on Embodiment 1, (b) is sectional drawing which shows the rotation locus part of the rotor electrode shown to (a). (A) represents the positional relationship between the rotor electrode and the stator electrode when obtaining the minimum capacity value, and (b) represents the positional relationship between the rotor electrode and the stator electrode when obtaining the maximum capacity value. 6 is a cross-sectional view of a variable capacitor according to Embodiment 2. FIG. 6 is a cross-sectional view illustrating a configuration of a plurality of convex portions of a variable capacitor according to a second embodiment. FIG. It is a top view of the stator which the variable capacitor concerning Embodiment 2 has. 6 is a cross-sectional view of a variable capacitor according to Embodiment 3. FIG. It is a bottom view of the rotor which the variable capacitor concerning Embodiment 3 has. It is sectional drawing showing the structure of the conventional variable capacitor. It is a bottom view of the rotor in the conventional variable capacitor. It is a top view of the stator in the conventional variable capacitor.

Embodiment 1
(Structure of variable capacitor 1)
FIG. 1 is a cross-sectional view of a variable capacitor 1 according to the first embodiment. FIG. 2 is a perspective view of the variable capacitor 1 according to the first embodiment. FIG. 3 is an exploded perspective view of the variable capacitor 1 according to the first embodiment. 4A is a bottom view of the rotor 21 included in the variable capacitor 1 according to the first embodiment, and FIG. 4B is a perspective view seen from the bottom surface side of the rotor 21 shown in FIG. FIG. 5 is a top view of the stator 31 included in the variable capacitor 1 according to the first embodiment. In FIG. 1, the description of some cross-sectional lines hidden by the driver 7 indicated by broken lines is omitted. The same applies to FIGS. 8, 11 and 13 described later in Embodiments 2 and 3.

  As shown in FIGS. 1 to 3, the variable capacitor 1 includes a stator 31 provided with a stator electrode 32, a rotor 21 placed on the stator 31 and provided with a rotor electrode 22, the stator 31 and the rotor. 21 and a frame 11 that holds the rotor 21 rotatably. The variable capacitor 1 is a capacitor whose capacitance can be adjusted by rotating the rotor 21. The rotor 21 is mounted on the top surface (mounting surface) of the stator 31.

  As shown in FIG. 1, the rotor 21 includes a rotor electrode portion 24 in which the rotor electrode 22 is disposed, and a non-electrode portion that is thinner than the rotor electrode portion 24 and is not in contact with the stator 31. 25 and a through hole (through hole) 23 through which a driver (tool) 7 for rotating the rotor 21 is inserted. Further, as shown in FIG. 4, the rotor 21 extends along the edge of the non-electrode portion 25 facing the stator 31 along the edge of the facing surface and is connected to the rotor electrode portion 24. In addition, ribs (first protrusions) 26 that are protrusions that are in contact with the rotor electrode part 24 are provided.

  The rotor 21 has a structure in which a rotor electrode 22 made of a metal material is embedded in a rotor electrode portion 24 that is a dielectric. The rotor electrode 22 is disposed in the rotor electrode portion 24 which is a thick part of the rotor 21 and in the vicinity of the surface facing the stator 31. Thereby, a dielectric is interposed between the rotor electrode 22 and the stator electrode 32.

  The thickness of the rotor 21 is from the top surface of the rotor 21 to the surface facing the mounting surface of the stator 31 in the rotor electrode portion 24 or the surface facing the mounting surface of the stator 31 in the non-electrode portion 25. Is the distance. In the present embodiment, the opposing surfaces of the rotor electrode portion 24 and the non-electrode portion 25 to the mounting surface of the stator 31 and the top surface of the rotor 21 are both flat and parallel to each other. And However, the present invention is not limited to this.

  As shown in FIG. 1, of the rotor 21, the rotor electrode portion 24 where the rotor electrode 22 is disposed is thick so that the rotor electrode 22 is brought closer to the stator 31, and the rotor electrode 22 is not disposed. The non-electrode portion 25 is thin. As shown in FIG. 4, the shape of the rotor 21 is, for example, a circular shape in a cross section perpendicular to the rotation axis of the rotor 21. The shape of the rotor 21 is not limited to a circular shape.

  As shown in FIGS. 1 and 4, the hole (through hole) 23 of the rotor 21 is provided at the position of the rotation shaft of the rotor 21. As shown in FIG. 4, the hole 23 of the rotor 21 has a polygonal shape such as a quadrangular cross section in a cross section perpendicular to the rotation axis of the rotor 21. In order to reduce the thickness of the rotor 21, which leads to a reduction in the thickness of the variable capacitor 1, the hole 23 of the rotor 21 is formed through the rotor 21. Alternatively, the hole 23 of the rotor 21 may have a shape in which a part of the circle is concave (convex) and engages with the convex (concave) portion of the driver 7. In other words, the cross-sectional shape of the hole 23 of the rotor 21 only needs to have a portion that engages with the driver 7 and the rotation of the driver 7 is transmitted to the rotor 21.

  For example, the rotor electrode portion 24 is a half portion on one side of the rotor 21, and the surface facing the stator 31 is in contact with the top surface of the stator 31. The rotor electrode 22 disposed in the rotor electrode portion 24 serves as a pair of electrodes with a stator electrode 32 described later.

  The non-electrode portion 25 is a half portion on the other side of the rotor 21, and the surface facing the stator 31 is separated from the top surface of the stator 31. The non-electrode portion 25 is separated from the top surface of the stator 31 and is not provided with a rotor electrode.

  The rib 26 supports the non-electrode part 25. This prevents the rotor 21 from tilting. The rib 26 extends along the edge of the non-electrode part 25 from one end connected to the rotor electrode part 24 to the other end connected to the rotor electrode part 24. In the present embodiment, the rib 26 has an arc shape.

  As shown in FIGS. 1 and 5, the stator 31 includes a stator electrode 32, a body 34 as a base, and a recess 33 provided on the top surface of the body 34. The body 34 is made of a dielectric material such as ceramic.

  The recess 33 is provided on the top surface of the body 34 (that is, the top surface of the stator 31) so as to communicate with the hole 23 of the rotor 21. The recess 33 has a circular cross section in a cross section perpendicular to the rotation axis of the rotor 21.

  The stator electrode 32 is disposed in the body 34 and in the vicinity of the top surface. Between the stator electrode 32 and the rotor electrode portion 24, a part of a body 34 made of a dielectric material in the vicinity of the top surface is interposed. One end of the terminal portion extending from the stator electrode 32 is connected to the stator electrode 32, is disposed downward along the side surface of the body 34 toward the other end, and is along the back surface of the body 34 in the vicinity of the other end. So that it bends.

  As shown in FIGS. 1 to 3, the frame 11 includes a spring action portion 12 and holding portions 14, 15, and 16 that are integrally formed. The spring action part 12 mainly covers the rotor 21. The holding portions 14, 15, and 16 cover the three side surfaces of the stator 31 and a part of the back surface.

  As shown in FIGS. 1 and 2, a portion of the top surface of the spring acting portion 12 (in other words, the top surface of the frame 11) that overlaps the hole 23 of the rotor 21 is an opening that exposes the hole 23 and the rotor 21 in the vicinity thereof. It becomes part 13. The side surface constituting the opening 13 is a portion that bends from the top surface of the frame 11 to the top surface side of the rotor 21. As for the side surface which comprises the opening part 13, the front-end | tip contacts the top | upper surface of the rotor 21. FIG. Thereby, the spring action part 12 acts as a spring which presses the rotor 21 toward the stator 31 side.

  As shown in FIGS. 2 and 3, the holding portions 14, 15, and 16 cover the stator 31 and the rotor 21 placed on the stator 31 with the frame 11, and then come into contact with the back surface of the stator 31 from the middle portion. Can be folded. Thereby, the frame 11 holds the rotor 21 and the stator 31.

(Operation of variable capacitor 1)
In order to explain the concept of variable capacitance, FIG. 6 shows a structure in which a dielectric is sandwiched between two electrodes (rotor electrode 22 and stator electrode 32). 6A is a perspective view showing a rotation locus portion of the rotor electrode 22 cut out from the variable capacitor 1, and FIG. 6B is a cross-sectional view showing a rotation locus portion of the rotor electrode shown in FIG. 7A shows the positional relationship between the rotor electrode 22 and the stator electrode 32 when obtaining the minimum capacity value, and FIG. 7B shows the positional relationship between the rotor electrode 22 and the stator electrode 32 when obtaining the maximum capacity value. FIG.

  When adjusting the capacitance of the variable capacitor 1, the driver 7 (see FIG. 1) is inserted into the hole 23 of the rotor 21 and the recess 33 of the stator 31. And the relative position of the rotor electrode 22 and the stator electrode 32 is adjusted by rotating the rotor electrode 22 as shown by the arrow D of (a) of FIG. Between the rotor electrode 22 and the stator electrode 32, a part of the rotor electrode portion 24 made of a dielectric and a part of the body 34 made of a dielectric are disposed.

  As shown in FIG. 7A, when the electrostatic capacitance of the variable capacitor 1 is desired to be a minimum value, the rotor electrode 22 is disposed at a position where the rotor electrode 22 and the stator electrode 32 do not overlap. As shown in FIG. 7B, when it is desired to set the capacitance of the variable capacitor 1 to the maximum value, the rotor electrode 22 is disposed at a position where the rotor electrode 22 and the stator electrode 32 overlap. As described above, the capacitance of the variable capacitor 1 can be changed by increasing or decreasing the area where the rotor electrode 22 and the stator electrode 32 face each other.

(Main advantages of variable capacitor 1)
According to the variable capacitor 1, the stator 31 has a recess 33 communicating with the hole 23 of the rotor 21 on the mounting surface on which the rotor 21 is mounted. Therefore, when the driver 7 is inserted into the through hole (hole 23) of the rotor, even if the foreign matter 9 is attached to the driver 7, the foreign matter 9 is a recess of the stator 31 as shown by an arrow A in FIG. It falls in 33 and is accommodated in the recess 33 that does not affect the characteristics of the variable capacitor 1. For this reason, even if a gap exists between the non-electrode portion 25 of the rotor 21 and the stator 31 and the foreign matter 9 is brought into the rotor 21 from the driver 7, the foreign matter 9 is prevented from entering the gap. Can do. As a result, while maintaining the size of the variable capacitor 1, it is possible to prevent a sudden change in capacitance due to the entry of foreign matter, and to improve reliability.

  In addition, when the rotor 21 is rotated, when the driver 7 is inserted into the hole 23 of the rotor 21, the driver 7 is also inserted into the concave portion 33 of the stator 31, and the rotor 21 is rotated. As a result, the rotation shaft is fixed as a result of the positioning of the driver 7 by the concave portion 33 of the stator 31, so that the eccentricity of the rotor 21 accompanying the rotation of the rotor 21 can be prevented. For this reason, it is possible to prevent a capacity deviation due to the eccentricity of the rotor 21.

  A circle indicated by an arrow C in FIG. Thus, the position of the rotating shaft of the rotor 21 is constant, and the rotating shaft is not displaced as shown in FIG.

  As shown in FIG. 3, the cross-sectional shape in a cross section perpendicular to the rotation axis of the rotor 21 is such that the hole 23 of the rotor 21 is a quadrangle, while the recess 33 of the stator 31 is a circle. For this reason, when the driver 7 having a square cross section is inserted into both the hole 23 and the recess 33, the corners of the driver 7 come into contact with the corners of the square hole 23, and the rotor 21 is rotated by rotating the driver 7. On the other hand, the corners of the driver 7 do not contact the inner side surface of the circular recess 33. Thereby, only the rotor 21 can be rotated among the stator 31 and the rotor 21.

  Further, according to the variable capacitor 1, the positions of the stator electrode 32 and the hole 23 are constant. Even if the position of the body cut that cuts the body 34 of the stator 31 from the base material to a predetermined size is shifted, the rotor 21 is rotated based on the position of the recess 33, so that the electrostatic capacity accompanying the rotation of the rotor 21 Can reduce the variation.

  The cross-sectional shape of the hole 23 is not limited to a quadrangle, and may be a triangle or a pentagon or more polygon according to the shape of the driver 7. Alternatively, the hole 23 of the rotor 21 may have a concave (convex) shape and a shape that engages with the convex (concave) shape portion of the driver 7. That is, the cross-sectional shape of the hole 23 of the rotor 21 may be configured so that the rotation of the driver 7 is transmitted to the rotor 21.

  In addition, the rotor 21 extends along the edge of the non-electrode portion 25 facing the stator 31 along the edge of the facing surface and is connected to the rotor electrode portion 24, and the rotor electrode portion on the mounting surface of the stator 31. 24 has a rib 26 which is in contact with 24. That is, the gap between the non-electrode portion 25 of the rotor 21 and the stator 31 can also be expressed as a portion surrounded by the rib 26 and the rotor electrode portion 24 that are in contact with the top surface of the stator 31. Further, the rib 26 can be expressed as having the same thickness as the rotor electrode portion 24 together with the non-electrode portion 25. As a result, as shown by an arrow B in FIG. 1, even if the foreign matter 9 enters the frame 11 from the gap between the frame 11 and the stator 31, the foreign matter 9 is brought into the non-electrode portion of the rotor 21 by the rib 26. It is possible to prevent the gap between the stator 25 and the stator 31 from entering. Thereby, it can prevent that a foreign material enters between the rotor electrode part 24 and the stator 31. FIG. Thereby, it is possible to prevent foreign matter from entering between the rotor 21 and the stator 31 from the side surface side of the rotor 21.

[Embodiment 2]
The second embodiment of the present invention will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 8 is a cross-sectional view of the variable capacitor 2 according to the second embodiment. FIG. 9 is a cross-sectional view illustrating the configuration of the plurality of convex portions 37 of the variable capacitor 2 according to the second embodiment. FIG. 10 is a top view of the stator 31 included in the variable capacitor 2. The variable capacitor 2 is different from the variable capacitor 1 in that a plurality of convex portions 37 disposed on the bottom surface of the concave portion 33 are disposed. Other configurations of the variable capacitor 2 are the same as those of the variable capacitor 1.

  As shown in FIGS. 8 and 9, the driver 7 is repeatedly inserted into the hole 23 of the rotor 21 and the recess 33 of the stator 31 in order to rotate the rotor 21. In the present embodiment, the tip of the driver 7 inserted into the recess 33 becomes thinner as it goes to the tip, but it does not have to be as thin as the driver 7 shown in the first embodiment. In the case where the tip end portion of the driver 7 becomes narrower toward the tip end, the inner diameter of the recess 33 may be smaller than the inner diameter of the hole 23 of the rotor 21.

  According to the variable capacitor 2, a plurality of convex portions 37 are disposed on the bottom surface of the concave portion 33. For this reason, the front-end | tip part of the driver 7 inserted in the recessed part 33 contacts the top | upper surface of the some convex part 37. FIG. Then, by rotating the driver 7, the foreign matter 9 attached to the tip portion of the driver 7 can be removed from the tip portion of the driver 7 by the top portion including the top surface of each of the plurality of convex portions 37. For this reason, the front-end | tip part of the driver 7 inserted in the hole 23 of the rotor 21 and the recessed part 33 of the stator 31 repeatedly can be cleaned. As a result, foreign matter 9 can be prevented from entering between the rotor 21 and the stator 31 due to the driver 7 being inserted into the hole 23 of the rotor 21 and the recess 33 of the stator 31.

  Furthermore, by using the same driver 7, it is possible to prevent foreign matter 9 from being carried into another variable capacitor different from the variable capacitor 2.

  As an example, the plurality of convex portions 37 may each have a truncated cone shape, and may be configured such that they are arranged on the bottom surface of the concave portion 33 without a gap or apart from each other. The plurality of convex portions 37 are not necessarily required to be plural, and the concave and convex shapes may be formed on the bottom surface of the concave portion 33 by one convex portion 37. For example, a convex portion 37 whose cross-sectional shape perpendicular to the rotation axis of the rotor 21 is a cross shape may be disposed on the bottom surface of the concave portion 33. Further, the convex portion 37 includes a brush-like shape. In addition, the shape of the convex part 37 is not limited to these.

[Embodiment 3]
The third embodiment of the present invention will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those described in the first and second embodiments are denoted by the same reference numerals and description thereof is omitted.

  FIG. 11 is a cross-sectional view of the variable capacitor 3 according to the third embodiment. FIG. 12 is a bottom view of the rotor 27 included in the variable capacitor 3 according to the third embodiment. The variable capacitor 3 is different from the variable capacitor 1 in that a rotor 27 is provided instead of the rotor 21. Other configurations of the variable capacitor 3 are the same as those of the variable capacitor 1. The rotor 27 includes a rib (second protrusion) 28 in addition to the configuration of the rotor 21.

  As shown in FIG. 12, the rib 28 is a surface facing the stator 31 in the non-electrode portion 25 of the rotor 21, extends along the edge of the hole 23 of the rotor 21, and is connected to the rotor electrode portion 24. Further, as shown in FIG. 11, the rib 28 has a height that makes contact with the placement surface of the stator 31 together with the rotor electrode portion 24. Thus, the rotor 27 is provided with the ribs 26 on the outer periphery, and is further provided with the ribs 28 on the inner periphery.

  Thus, the hole 23 of the rotor 21 is surrounded by the rib 28 and the rotor electrode portion 24. Further, the rib 28 can be expressed as having the same thickness as the rotor electrode portion 24 together with the non-electrode portion 25. For this reason, it can prevent that the foreign material 9 enters into the clearance gap between the non-electrode part 25 of the rotor 21 and the stator 31 resulting from inserting the driver 7 in the hole 23 of the rotor 21. As a result, it is possible to more reliably prevent foreign matter 9 from entering between the contact surfaces of the rotor 21 and the stator 31.

[Summary]
The variable capacitors 1 to 3 according to the first aspect of the present invention include a stator 31 on which a stator electrode 32 is disposed and a rotor 21 placed on the stator 31, and the rotor 21 is a thick portion. A rotor electrode portion 24 on which the rotor electrode 22 is disposed, a non-electrode portion 25 that is thinner than the rotor electrode portion 24 and is not in contact with the stator 31, and a through hole (hole 23), The stator 31 has a recess 33 communicating with the through hole (hole 23) on a mounting surface (top surface) on which the rotor 21 is mounted.

  According to the above configuration, the stator has a recess communicating with the through hole on the mounting surface on which the rotor is mounted. Therefore, even if a foreign object enters the through hole, the foreign object is not in the stator. Housed in the recess. For this reason, it is possible to prevent the foreign matter from entering between the rotor and the stator.

  The variable capacitors 1 to 3 according to aspect 2 of the present invention are the above-described aspect 1, wherein the cross-sectional shape in a cross section perpendicular to the rotation axis of the rotor 21 is a tool for rotating the rotor 21 (the through hole (hole 23)). Preferably, the recess 33 is circular in shape with a portion engaging the driver 7).

  According to the above configuration, since the through hole has a cross-sectional shape that engages with a tool for rotating the rotor, the stator and the rotor are inserted when the tool is inserted into both the through hole and the recess. Of these, only the rotor can be rotated. Therefore, by inserting the tool into the through hole of the rotor and rotating the rotor, the relative positions of the rotor electrode part and the non-electrode part of the rotor and the stator electrode can be adjusted. As a result, the capacitance of the variable capacitor can be adjusted. When the rotor is rotated, the tool is inserted into the through hole of the rotor and also into the concave portion of the stator, and the rotor is rotated. As a result, the rotating shaft is fixed as a result of positioning of the tool by the concave portion of the stator, so that eccentricity of the rotor accompanying rotation of the rotor can be prevented.

  In the variable capacitor 2 according to aspect 3 of the present invention, in the above aspect 1 or 2, it is preferable that a convex portion 37 is disposed on the bottom surface of the concave portion. According to the said structure, the foreign material adhering to the front-end | tip part of the tool inserted in the said recessed part can be removed by the said convex part. For this reason, even if the tool is repeatedly used, it is possible to prevent foreign matter from entering the rotor and the stator due to the tool being inserted into the through hole and the recess.

  In the variable capacitors 1 to 3 according to the aspect 4 of the present invention, in the above aspects 1 to 3, the rotor 21 is formed on the surface of the non-electrode portion 25 that faces the mounting surface of the stator 31. The first protrusion (rib 26) having a height that contacts with the rotor electrode 24 is provided on the upper surface of the stator 31 while extending along the edge and connected to the rotor electrode 24. Also good. With the above configuration, it is possible to prevent foreign matter from entering between the rotor and the stator from the side of the rotor.

  The variable capacitor 3 according to the fifth aspect of the present invention is the variable capacitor 3 according to the first to fourth aspects described above, wherein the rotor 27 is formed on the surface of the non-electrode portion 25 that faces the mounting surface of the stator 31. ) And is connected to the rotor electrode portion 24, and has a second protrusion (rib 28) having a height that contacts the rotor electrode portion 24 on the mounting surface of the stator 31. May be. With the above configuration, it is possible to more reliably prevent foreign matter from entering between the contact surfaces of the rotor and the stator, which are caused by inserting the tool into the through hole.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  The present invention can be used for a variable capacitor.

1-3 Variable capacitor 7 Driver (tool)
9 Foreign object 11 Frame 21/27 Rotor 22 Rotor electrode 23 Hole (through hole)
24 Rotor electrode portion 25 Non-electrode portion 26 Rib (first protrusion)
28 Rib (second protrusion)
31 Stator 32 Stator Electrode 33 Concave 34 Body 37 Convex

Claims (5)

A stator on which a stator electrode is arranged, and a rotor mounted on the stator,
The rotor includes a rotor electrode portion in which the rotor electrode is disposed, a non-electrode portion that is thinner than the rotor electrode portion and is not in contact with the stator, and a through hole.
The variable capacitor according to claim 1, wherein the stator has a recess communicating with the through hole on a mounting surface on which the rotor is mounted.   The cross-sectional shape in a cross section perpendicular to the rotation axis of the rotor is such that the through hole has a portion that engages with a tool for rotating the rotor, and the concave portion is circular. The variable capacitor described in 1.   The variable capacitor according to claim 1, wherein a convex portion is disposed on a bottom surface of the concave portion.   The rotor extends along the edge of the facing surface on the surface facing the stator mounting surface in the non-electrode portion and is connected to the rotor electrode portion. The variable capacitor according to any one of claims 1 to 3, further comprising a first protrusion having a height that contacts the rotor electrode portion.   The rotor extends along the edge of the through hole on the surface of the non-electrode portion that faces the mounting surface of the stator, and is connected to the rotor electrode portion. The variable capacitor according to any one of claims 1 to 4, further comprising a second protrusion having a height that contacts the rotor electrode.

Images