JP3355754B2 - Variable capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable capacitor capable of adjusting a minute capacitance, and more particularly to a thin variable capacitor capable of adjusting both sides.

[0002]

2. Description of the Related Art As a conventional variable capacitor capable of adjusting both sides, Japanese Patent Application No. 5-7 has been proposed by the same applicant.
No. 8698 will be described as an example.

[0005] In FIG. 5, a variable capacitor 1 includes a metal rotor 2, a stator 4 disposed on the lower surface side of the rotor 2 and having a fixed electrode 3, and a spring member for pressing the rotor 2 against the stator 4. (Spring washer) 5 and the elastic force of rotor 2, stator 4 and spring member 5
Is pressed against the upper surface of the stator 4 to hold the rotor 2 slidably on the stator 4.

[0004] The rotor 2 is made of a metal such as brass, and has a first through hole 2 through which a shaft 6 penetrates in the center.
The first through hole 2a is formed to have a substantially rectangular cross section corresponding to the shape of the rotor 2 penetrating portion 6a of the shaft 6 so as to rotate together with the shaft 6. Further, on the upper surface of the rotor 2, a plus-shaped groove 12 for rotating the rotor 2 with a driver (not shown) as a rotation tool from the outside is formed. on the other hand,
A substantially lower half of the lower surface of the rotor 2 facing the stator 4 projects to form a movable electrode 13a. In order to prevent the rotor 2 from inclining with respect to the stator 4, a convex protrusion 14 is provided on a part of the movable electrode 13 b that has receded on the surface of the rotor 2 facing the stator 4.

[0005] The stator 4 is made of a ceramic dielectric, and has a second through-hole 8 formed at the center thereof, through which the shaft 6 passes. The fixed electrode 3 is formed inside the stator 4, external electrodes 9a and 9b are formed on both ends, and a rotor extraction electrode 10 is formed on the lower surface. The fixed electrode 3, the external electrode 9a, and the external electrode 9b are formed. And rotor extraction electrode 1
0 is electrically connected to each other. Further, the external electrode 9b is electrically connected to the rotor 2 via the rotor extraction electrode 10, the shaft 6, and the spring member 5.

The shaft 6 has a shaft 6a at one end and a head 6b at the other end. The shaft portion 6a penetrates through the stator 4, the rotor 2, and the spring member 5, and is caulked so as to engage with the spring member 5, and the upper surface of the head portion 6b engages with the lower surface of the stator 4. Further, the rotor penetrating portion 6c of the shaft 6 is formed in a square shape corresponding to the shape of the first through hole 2a of the rotor 2 so that the rotor 2 can rotate together. Further, the head portion 6b of the shaft 6
Is formed with a driver groove 7 for engaging a driver.

In the variable capacitor 1 having such a configuration, a capacitance is formed between the fixed electrode 3 and the movable electrode 13a via the ceramic dielectric of the stator 4, and the movable electrode 13
a, that is, the capacitance can be adjusted by rotating the rotor 2, and the capacitance is electrically connected to the external electrode 9 a that is electrically connected to the fixed electrode 3 and to the rotor extraction electrode 10 through the shaft 6. The external electrode 9b is taken out to the outside. The variable capacitor 1 is inserted and locked into a driver groove 12 of the rotor 2 from the upper surface side and into a driver groove 7 of the shaft 6 from the lower surface and is rotated. The capacity can be adjusted.

[0008]

However, in the variable capacitor 1 having such a configuration, the thickness T of the entire variable capacitor 1 is equal to the thickness T1 of the rotor 2, the thickness T2 of the stator 4, and the thickness T3 of the head portion 6b of the shaft 6. In total, it is necessary to further reduce the thickness T in order to meet the recent demand for electronic devices to reduce the height of electronic components. Also,
Driver groove 1 of rotor 2 on the upper surface side of variable capacitor 1
Since the shape of the driver groove 7 is different from that of the driver groove 7 of the shaft 6 on the lower surface side, there is also a problem that two types of drivers are required for adjusting the capacity of the variable capacitor 1.

Further, since the shapes of the rotor 2 and the shaft 6 are complicated, there is a problem in that the fabrication of these members is difficult, and the cost is high.

SUMMARY OF THE INVENTION An object of the present invention is to provide a variable capacitor which has a thin structure and can be adjusted on both sides by using a member having a simple structure.

[0011]

According to the present invention, in order to achieve the above object, a rotor having a first through hole into which a driver for turning can be inserted and having a movable electrode is provided by a fixed electrode. Is mounted via a dielectric and rotatably mounted on a stator having a second through-hole formed in the stator, and a first through-hole of the rotor is formed through the second through-hole. It is characterized in that a driver can be inserted into the through hole.

Further, the stator is made of a dielectric material, the fixed electrode is formed in the dielectric material, the rotor is made of metal, and a protrusion is formed on one surface of the rotor, and the protrusion is a movable electrode. It is characterized by the following.

On the other hand, the stator is made of an insulator, and the fixed electrode is formed on a surface of the stator. The rotor is made of a dielectric, and a movable electrode is formed in the dielectric. It is characterized by the following.

A stator made of a dielectric material and having a fixed electrode therein and an external electrode at an end portion electrically connected to the fixed electrode, and a metal made to rotate with respect to the stator. A first electrode having a first through-hole into which a driver can be inserted, and a movable electrode having a substantially semicircular protrusion at least on a lower surface thereof; the rotor being rotatable; And a cover that integrally engages the first and second through holes. A second through hole is formed in the stator, and a driver can be inserted into the first through hole of the rotor through the second through hole. It is characterized by the following.

[0015]

According to the present invention, since the second through hole is provided in the stator at the first through hole for locking the driver for rotating the rotor, the driver for rotating the rotor is provided. In this configuration, a driver can be inserted and locked in the first through hole of the rotor from both upper and lower surfaces of the stator, and the rotor can be rotated from both upper and lower surfaces of the variable capacitor.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a variable capacitor according to the present invention will be described below with reference to FIGS.

In FIG. 1, a variable capacitor 21 includes a metal rotor 22, a stator 24 having a fixed electrode 23 rotatably disposed on the lower surface side of the rotor 22, and presses the rotor 22 against the stator 24. And a cover 25 made of metal.

As shown in FIG. 2, the rotor 22 is made of a substantially disk-shaped metal such as brass, and has a substantially rectangular first through hole 26 which is a driver groove at a substantially center thereof. . On the lower surface of the rotor 22, a movable electrode 29a composed of a substantially semicircular protrusion is formed.
The movable electrode 2 on the surface of the rotor 22 facing the stator 24 so that the movable electrode 2 can rotate smoothly on the stator 24.
A columnar projection 30 is formed on a part of 9b.

The stator 24 is made of a dielectric ceramic, has fixed electrodes 23 disposed at predetermined positions inside, and has external electrodes 24a and 24b formed at both ends. The external electrodes 24a are electrically connected to the fixed electrodes 23. Connected. At a substantially center of the stator 24, a second through hole 27, which is a circular tool or the like, into which a driver (not shown) can be inserted and the driver can rotate, is provided in the thickness direction. A depression 28 is formed on the lower surface of the stator 24 except for the end where the external electrodes 24a and 24b are formed. Note that two fixed electrodes 23 are provided inside the stator 24 with the second through hole 27 as the center of symmetry.
This is to eliminate the directionality of the stator 24 when assembling the variable capacitor 21, and one of them is a dummy electrode. For example, the fixed electrode 23 connected to the external electrode 24b is a rotor 2 having a movable electrode 29a.
2 and becomes a dummy electrode.

The cover 25 is made of a metal plate such as stainless steel and has a cylindrical portion 31 for accommodating the rotor 22. A third through hole 3 in which a driver can be inserted and the driver can rotate, in the center of the closed end 31a of the cylindrical portion 31.
2 is provided on the open end side of the cylindrical portion 31.
A flange portion 33 is formed in contact with the upper surface of the fourth member 4.
A pair of claws 34a, 34b and a rotor-side terminal 35 are formed in the flange portion 33 at positions facing the side ends thereof in a direction perpendicular to a line connecting the claws 34a, 34b. Also,
Closed end 31 of cylindrical portion 31 provided with third through hole 32
For example, a is formed in the shape of a bowl in the direction of the open end of the cylindrical portion 31 so as to have a spring property in the vertical direction of the drawing like a spring washer.

Next, when the variable capacitor 21 is constructed, the relationship among the above-described members will be described in order.

First, the rotor 22 is mounted on the upper surface of the stator 24.
The movable electrode 29a is placed in contact with the movable electrode 29a. Then, the rotor 22 is accommodated in the cylindrical portion 31 of the cover 25,
5 is in contact with the upper surface of the stator 24 and the rotor side terminal 35 is in contact with the external electrode 24b, and the ends of the claws 34a and 34b of the cover 25 are fixed to the stator 2
Then, the rotor 22, the stator 24, and the cover 25 are integrally engaged with each other by being bent so as to be accommodated in the fourth recess 28. At this time, the rotor 22 is fixed to the stator 24 by the elastic force of the closed end 31a provided on the cylindrical portion 31b of the cover 25.
To hold the rotor 22 rotatably on the stator 24.

In the variable capacitor 21 having such a structure, a capacitance is formed between the fixed electrode 23 and the movable electrode 29a via the ceramic dielectric of the stator 24, and the movable electrode 29a, that is, the rotor 22 is rotated. By doing so, the capacitance can be adjusted. The external electrode 24a that is electrically connected to the fixed electrode 23 and the external electrode 24 that is electrically connected to the movable electrode 29a through the rotor 22 and the cover 25 can be adjusted.
b (rotor side terminal 35) is taken out to the outside.

The variable capacitor 21 is connected to a first through hole 26 of the rotor 22 through a third through hole 32 of the cover 25 by a driver (not shown).
Can be inserted and locked, and a driver can be inserted and locked into the first through hole 26 of the rotor 22 through the second through hole 27 of the stator 24 from the lower surface side. In other words, the same driver can be inserted and locked into the first through hole 26 from both the upper and lower surfaces of the stator 24 and the rotor 22 can be rotated to adjust the capacitance.

The variable capacitor 21 in this embodiment is
Although the cover 25 has an elastic function like a spring washer, a separate spring washer (not shown) is inserted between the closed end 31 a of the cover 25 and the upper part of the rotor 22, so that the stator 24 The rotor 22 can also be pressed against the upper surface.

Further, the shape of the movable electrode 29a is not limited to a semicircle, and may be formed in another shape such as a fan, although not particularly shown. Also, the shape of the projection 30 is not limited to a columnar shape, and may be formed in other various shapes. Although not particularly shown, for example, along the outer periphery of the movable electrode 29 b on the lower surface of the rotor 22. Such an arc-shaped projection may be formed. Also, there is no special restriction on the positional relationship between the first through hole 26, the movable electrode 29a, and the projection 30, and the first through hole 26 can be formed at an arbitrary position.

Next, another embodiment of the present invention will be described with reference to the sectional view shown in FIG. In FIG. 3, a variable capacitor 41 is made of an insulating resin, and has a case 42 having an opening 42a for inserting a driver in an upper portion, a rotor 44 having a movable electrode 43 formed therein, and a fixed electrode 45 formed on the surface. The stator 44 is accommodated, and the rotor 44 is pressed by a spring portion 47a integrally formed with a rotor-side terminal 47, which is one of the external electrodes.
3 and a stator-side terminal 48, which is the other external electrode electrically connected to the fixed electrode 45, is drawn out of the case 42.

As shown in FIG. 4, the rotor 44 is made of a substantially disk-shaped dielectric, and has a first through hole 49 at the center thereof into which a substantially square driver can be inserted and locked. . A movable electrode 4 such as a semicircle is provided inside the rotor 44.
3, and an extraction electrode 43a is formed on the upper surface via the side end surface of the rotor 44, for example.

The stator 46 is made of, for example, an insulator such as alumina, and a driver (not shown) for rotating the rotor 44 can be inserted substantially in the center, and a second through hole 50 in which the driver can rotate. Is provided. A fixed electrode 45 having a semicircular shape or the like is formed on the upper surface of the stator 46, and the fixed electrode 45 is electrically connected to, for example, an extraction electrode 45a formed on the lower surface via a side end surface of the stator 46.

The rotor side terminal 47 and the stator side terminal 48
Is formed, for example, of a metal material having a spring property. The rotor side terminal 47 is formed integrally with the spring portion 47a, and the extraction electrode 43a on the upper surface of the rotor 44 and the spring portion 47a.
It is electrically connected to the movable electrode 43 via a. The stator terminal 48 is electrically connected to the fixed electrode 45 via an extraction electrode 45a on the lower surface of the stator 46.

In the variable capacitor 41 having such a configuration, similarly to the above-described variable capacitor 21, the upper side is provided through the opening 42a, and the lower side is provided with the stator 46.
The rotor 44 can be rotated by the same driver via the second through-hole 50 provided in the rotor. Therefore, the capacitance can be adjusted from both sides of the variable capacitor 41, and when adjusting the capacitance, the capacitance value changes little and is stable.

The shape of the first through holes 26 and 49 provided in the rotors 22 and 44 is not limited to a square shape, and is not particularly shown except for a circular shape. Rotors 22 and 44
Can be rotated as long as it can rotate.

As described above, in the variable capacitors 21 and 41 according to the present invention, as shown in FIGS.
Depth T5 of the allowance for the driver of the rotors 22 and 44
And the depth T5 of the catching allowance of the driver of the conventional rotor 2 shown in FIG.
4, the thickness T of the bottom of the driver groove 12 of the rotor 2
A thickness corresponding to 6 is not required. For this reason, compared with the conventional rotor 2, the thickness T5 of the rotors 22 and 44 is
It can be thinned by the thickness T6. Further, in the variable capacitors 21 and 41 according to the present invention, the thickness T3 of the head portion 6b of the shaft 6 shown in FIG. Therefore, the product height of the variable capacitors 21 and 41 is almost the same as that of the conventional capacitor (T
6 + T3), which makes it possible to correspond to a small electronic device whose height is desired to be reduced.

When the rotors 22 and 44 are rotated to adjust the capacitance, no load is applied to the rotors 22 and 44 in the driver insertion direction (downward in the figure) by the driver, so that the fixed electrodes 23 and movable electrode 29
a, and the distance between the fixed electrode 45 and the movable electrode 43 hardly changes.
And 41 are small and stable.
Since the tip of the driver does not come into contact with the steps 24 and 46, the thickness of the rotors 22 and 44 can be used as it is as the allowance T5 for the driver, so that the rotation can be performed reliably. And the rotor 22
And 44 the mourning can be made even thinner.

Further, since there is no need to regulate the load on the rotors 22 and 44 by the driver in the driver insertion direction, it is suitable for automatic adjustment by a machine.

[0036]

As described above, in the variable capacitor according to the present invention, the driver is inserted into and locked in the first through hole of the rotor from the upper surface side, and the rotor is rotated. The driver can be rotated by passing the driver through the second through hole of the stator and inserting and locking the driver into the first through hole of the rotor. Therefore, the capacitance can be adjusted by rotating the rotor from both sides of the variable capacitor. In addition, since the first through hole of the common rotor can be inserted and locked by a driver, it can be adjusted from both sides by one type of driver.

Further, it is possible to use a rotor and a cover which are easy to process without using a rotor and a shaft having a complicated shape, thereby realizing a low cost. In addition, the thickness of the variable capacitor can be reduced by the thickness corresponding to the thickness required for the head portion and the caulked portion of the conventional shaft. In addition, since the rotation of the rotor can be reliably performed, the thickness of the rotor can be reduced.

[Brief description of the drawings]

1A and 1B show an embodiment of a variable capacitor according to the present invention, wherein FIG. 1A is a top view, FIG. 1B is a front sectional view, and FIG.
Is a bottom view.

2A is an exploded perspective view of FIG. 1, and FIG. 2B is a perspective view of the member of FIG.

FIG. 3 is a sectional view showing another embodiment of the variable capacitor according to the present invention.

FIG. 4 is a perspective view showing an upper surface side of the stator according to the embodiment of FIG. 3;

5A and 5B show a conventional variable capacitor, in which FIG. 5A is a top view, FIG. 5B is a front sectional view, and FIG. 5C is a bottom view.

[Explanation of symbols]

 21, 41 Variable capacitor 22, 44 Rotor 23, 45 Fixed electrode 24, 46 Stator 24a, 47 External electrode (rotor side electrode) 24b, 48 External electrode (stator side electrode) 25, 42 Cover (case) 26, 49 First Through hole 27,50 second through hole 29a, 43 movable electrode

Claims (7)

(57) [Claims] 1. A rotor having a first through-hole into which a driver for turning can be inserted and having a movable electrode is mounted on a stator having a fixed electrode via a dielectric.
The rotor is rotatably mounted, a second through hole is formed in the stator, and a driver can be inserted into the first through hole of the rotor through the second through hole. And a variable capacitor. 2. The variable capacitor according to claim 1, wherein said stator is made of a dielectric, and said fixed electrode is formed in said dielectric. 3. The variable capacitor according to claim 1, wherein the rotor is made of metal, and a protrusion is formed on one surface of the rotor, and the protrusion is a movable electrode. 4. The variable capacitor according to claim 1, wherein the stator is made of an insulator, and the fixed electrode is formed on a surface of the stator. 5. The rotor according to claim 1, wherein the rotor is made of a dielectric, and a movable electrode is formed in the dielectric.
Or the variable capacitor according to 4. 6. It is made of a dielectric, has a fixed electrode inside,
A stator having an external electrode at an end portion electrically connected to the fixed electrode; and a first through hole made of metal, into which a driver for rotating the stator can be inserted, and at least A rotor having a movable electrode formed of a substantially semicircular protrusion on the lower surface, and a cover for rotatably rotating the rotor and integrally engaging the rotor and the stator. A variable capacitor, wherein two through holes are formed, and a driver can be inserted into the first through hole of the rotor via the second through hole. 7. It is made of a dielectric, has a fixed electrode inside,
A stator having an external electrode at an end portion electrically connected to the fixed electrode; and a first through hole made of metal, into which a driver for rotating the stator can be inserted, and at least A rotor having a movable electrode formed of a substantially semicircular protrusion on the lower surface, a spring washer made of metal and abutting on the upper surface of the rotor, and the rotor being rotatable so that the spring washer, the rotor, and the stator can be rotated; A second through hole is formed in the stator, and a driver can be inserted into the first through hole of the rotor through the second through hole. A variable capacitor characterized by the following.