JP2002141249A - Variable capacitor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable capacitor whose stability is high by a method where a driver plate and an electrode plate, which constitute a rotor are formed individually and they are integrated, and to provide its manufacturing method. SOLUTION: The rotor 3 in the variable capacitor is constituted with the driver plate 8 and the electrode plate 7 being formed individually and that they are integrated, by using engaging protrusions 7b which are installed in the circumferential part of the electrode plate 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable capacitor used for various electronic devices and a method for manufacturing the same.

[0002]

2. Description of the Related Art The basic structure of a variable capacitor is such that a rotor is rotatably arranged on a stator having stator electrodes.

A rotor used for such a variable capacitor has a generally disk-shaped driver plate forming an adjusting jig engaging portion on the upper surface side of a conventional rotor, and a substantially disk-shaped driver plate forming a rotor electrode portion on the lower surface side of the rotor. The fan-shaped electrode plate is formed of a single metal plate whose outer peripheral portion is connected, and the connected portion is bent so that both are overlapped.

[0004]

However, when a rotor is formed by bending a single metal plate, stress is applied so that the bent portion is opened due to its elastic deformation characteristics so that the overlapped driver plate and electrode plate are opened. As a result, the stress induces rattling of the rotor with respect to the stator, and as a result, the stability of the variable capacitor is deteriorated.

Accordingly, the present invention is to solve such a problem and to provide a variable capacitor having high stability and a method for manufacturing the same.

[0006]

According to the first aspect of the present invention, a driver plate and an electrode plate are separately formed and integrated with each other. In addition, the stress caused by bending which has conventionally occurred can be eliminated, and the stability of the variable capacitor can be improved.

According to the second aspect of the present invention, by providing a plurality of engaging projections, the integration between the driver plate and the electrode plate can be further strengthened.

In the invention according to claim 3 of the present invention, by providing the engaging projections near both ends of the arc in the outer peripheral portion of the electrode plate, it is possible to efficiently and stably integrate with a small number of engaging projections. .

According to a fourth aspect of the present invention, a notch is provided in a circumferential portion of the driver plate, and an engaging projection is engaged with the notch, so that the electrode plate is provided in the notch. Since the engaging projections are engaged, they are sufficiently integrated in the rotation direction of the rotor.

According to a fifth aspect of the present invention, a special processing method is used by projecting the engaging projection from the upper surface of the driver plate and caulking the projecting portion to the upper surface of the driver plate. Therefore, the driver plate and the electrode plate can be integrated with high accuracy.

According to the invention described in claim 6 of the present invention, by providing a supporting portion projecting downward at the electrode plate non-contact position on the driver plate, rattling of the rotor electrode with respect to the stator can be suppressed. .

In the invention according to claim 7 of the present invention, by providing the support portion on an extension of the center line of the electrode plate, the support portion is provided in a direction which is easily affected by the step of the electrode plate. Further, rattling of the rotor can be suppressed.

[0013] According to an eighth aspect of the present invention, at least one of the driver plate and the electrode plate is formed in a hoop shape, and one of the driver plate and the electrode plate formed in the hoop shape is provided to one of the driver plate and the electrode plate. By assembling the other, the productivity of the variable capacitor can be improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view of a variable capacitor used in various electronic devices. In this variable capacitor, a stator 1 having a stator electrode (not shown) on a lower surface side, which will be described later, is housed and fixed on an upper portion of a resin substrate 2, a rotor 3 is mounted on an upper surface of the stator 1, and a spring is The rotor 4 is rotatably pressed against the stator 1 by covering the cover 4.

Looking at each component, the stator 1 is formed by forming a ceramic plate into a D-shape, and a substantially semicircular stator electrode (not shown) is provided on the lower surface.

The resin substrate 2 on which the stator 1 is housed and fixed is formed by molding a dielectric resin into a substantially rectangular shape.
A substantially D-shaped concave portion 2a that is the same as the outer shape of the stator 1 that houses the stator 1 is formed in a central portion on the upper surface side. Further, inside the resin substrate 2, one end is electrically connected to a stator electrode (not shown), and the other end is a metal hot terminal 2b led to an external connection portion of the variable capacitor. Is molded with a metal hot terminal 2c which is electrically connected to the spring cover 4 and the other end of which is led to an external connection portion of the variable capacitor.

The rotor 3 has a lower surface facing the above-mentioned stator electrode (not shown) via a ceramic layer, and a rotor electrode 5 for forming a capacitance, and an upper surface for inserting and adjusting an adjusting driver. Driver groove 6.

The spring cover 4 is formed of a metal plate. The upper surface is provided with a through hole 4a at the center for exposing the driver groove 6, and the peripheral portion of the through hole 4a is bent downward to provide a spring property. Thus, the rotor 3 is pressed against the stator 1. In addition, the lower ends of the legs 4b provided on both sides of the spring cover 4 are engaged with the hot terminals 2c exposed on the side surfaces of the resin substrate 2, so that the resin substrate 2, the stator 1, the rotor 3, and the spring cover 4 are attached. The structure is integrated.

As shown in FIG. 2, the rotor 3 of this variable capacitor is formed of a substantially fan-shaped metal plate so that the rotor electrode 5 is formed on the lower surface and the driver groove 6 is formed on the upper surface. It has a structure in which an electrode plate 7 to be used and a driver plate 8 formed of a disk-shaped metal plate and provided with a rectangular through-hole 8a which forms a driver groove 6 in the center portion are superposed. The lower end of the through hole 8a forming the driver groove 6 is sealed by a protruding portion 7a formed in the center of the electrode plate 7.

When the electrode plate 7 and the driver plate 8 are integrated, the electrode plate 7
Are provided on the outer peripheral portion of the driver plate 8, and the engaging protrusion 7b is caulked to the outer peripheral end portion of the driver plate 8 to integrate the two.

By forming the rotor 3 in this manner, the above-described electrode plate 7 and driver plate 8 are formed from a single metal plate and bent at the connection portion. Unlike the conventional structure in which the stability is deteriorated, the stability of the variable capacitor can be improved.

That is, by providing the engagement projection 7b on the electrode plate 7 and caulking the outer peripheral end portion of the driver plate 8, the engagement projection 7b bent by the caulking is provided.
However, the tip of the engaging projection 7b is a free end, and the electrode plate 7 is not opened from the driver plate 8 but is a free end due to this stress. Is opened, and the caulking portion of the engaging projection 7b, which is important for integration of the rotor 3, is not greatly affected.

Further, in this variable capacitor, the engaging projection 7b is formed by an arc 7c at the outer peripheral end of the electrode plate 7.
And one near each end of the
By providing a plurality of engagement projections 7b on the electrode plate 7, the integration with the driver plate 8 can be further strengthened, and by providing one engagement projection 7b near each end of the arc 7c, a circle can be obtained. Since the engaging projections 7b are engaged substantially on the diagonal line of the plate-shaped driver plate 8, it is possible to efficiently and stably integrate them with a few engaging projections 7b. In addition, the productivity is improved by effectively arranging the engagement projections 7b and reducing the number thereof.

Further, a notch 8b is provided at a position corresponding to the engagement projection 7b on the circumferential portion of the driver plate 8, and when the driver plate 8 and the electrode plate 7 are stacked, the engagement projection 7b is notched. By inserting and caulking so as to fit into the portion 8b, the electrode plate 7 is integrated so as to hold the driver plate 8, so that the rotor 3 can be integrated in the up-down direction and the inside of the cutout 8b of the driver plate 8 The engagement projections 7b provided on the electrode plate 7 are engaged with each other, so that they are sufficiently integrated even in the rotation direction of the rotor 3.

When the engagement projections 7b are provided on the electrode plate 7 as described above, not on the driver plate 8, the surface on which the engagement projections 7b are caulked forms the rotor electrode 5. Since it is formed on the upper surface of the driver plate 8 which is the upper surface of the rotor 3 which does not need the flatness, it is not on the lower surface side of the electrode plate 7 which is required to have a high flatness. The structure is such that its characteristics do not deteriorate without using a processing method.

At a position 8c of the driver plate 8 where the electrode plate 7 is not in contact with the electrode plate 7, a support portion 8d is provided by bending a portion of the driver plate 8 downward as shown in FIG. The height of the bent support portion 8 d is made equal to the thickness of the electrode plate 7 as shown in FIG. 4, so that the rotor is formed by a step between the lower surface of the electrode plate 7 and the lower surface of the driver plate 8 when the variable capacitor is assembled. 3 has a structure in which rattling is suppressed.

Also, as shown in FIG. 3, by providing this support portion 8d on an extension of the center line 9 of the fan-shaped electrode plate 7, the support portion 8d is oriented in a direction easily affected by the step of the electrode plate 7. Therefore, the rotor 3 has a structure in which rattling is suppressed.

In the assembling step of the driver plate 8 and the electrode plate 7, as shown in FIG. 5, a plurality of electrode plates 7 are formed as hoop members 11 connected to the metal strip 10 at predetermined intervals. This hoop material 11
If the driver plate 8 is mounted on the basis of the above, the production becomes easy. Here, the description has been made using the configuration in which the electrode plate 7 is the hoop material 11, but either the electrode plate 7 or the driver plate 8, Alternatively, the same effect can be obtained by forming both of them as the hoop material 11.

Further, in one embodiment of the present invention, the support portion 8d cuts and protrudes one portion of the outer circumference of the driver plate 8, but the same effect can be obtained even if it is more than one portion. It is. The supporting portion 8d may be formed by bending the outer peripheral end of the driver plate 8 downward as shown in FIG. 6 or by bending the outer peripheral end of the driver plate 8 downward as shown in FIG. The tip portion may be bent further upward, that is, the support portion 8 extends on the extension of the lower surface of the electrode plate 7.
The same effect can be obtained regardless of the form in which the bottoms of d coincide with each other.

[0031]

As described above, according to the present invention, the driver plate and the electrode plate constituting the rotor are separately formed, and are integrated with each other.
The stability of the variable capacitor can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a variable capacitor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a rotor used for the variable capacitor.

FIG. 3 is a bottom perspective view of a driver plate forming the rotor.

FIG. 4 is a sectional view of the rotor.

FIG. 5 is a perspective view of a hoop material formed when assembling the rotor.

FIG. 6 is a cross-sectional view of a driver plate according to another embodiment.

FIG. 7 is a cross-sectional view of a driver plate according to still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 2 Resin board 3 Rotor 4 Spring cover 5 Rotor electrode 6 Driver groove 7 Electrode plate 7b Engagement projection 8 Driver plate

Claims (8)

[Claims] 1. A stator, comprising a substantially disk-shaped rotor rotatably disposed on the stator, wherein the rotor has a disk-shaped driver plate forming an upper surface side and a substantially disk-shaped driver plate forming a lower surface side. A variable capacitor formed from a fan-shaped electrode plate and provided with engaging projections on a circumferential portion of the electrode plate and engaging the engaging projections with the driver plate to integrate them. 2. The variable capacitor according to claim 1, wherein a plurality of engaging projections are provided. 3. The variable capacitor according to claim 2, wherein engagement projections are provided on both ends of the arc in the outer peripheral portion of the electrode plate. 4. The variable capacitor according to claim 1, wherein a notch is provided in a circumferential portion of the driver plate, and an engaging projection is engaged with the notch. 5. The variable capacitor according to claim 4, wherein the engaging projection is projected from an upper surface of the driver plate, and the projected portion is swaged on the upper surface side of the driver plate. 6. The variable capacitor according to claim 1, wherein a supporting portion protruding downward is provided at a position of the driver plate that is not in contact with the electrode plate. 7. The variable capacitor according to claim 6, wherein the support portion is disposed on an extension of a center line of the electrode plate. 8. A stator, and a substantially disk-shaped rotor rotatably disposed on the stator, wherein the rotor has a disk-shaped driver plate forming an upper surface and a substantially disk-shaped driver plate forming a lower surface. A variable capacitor formed from a fan-shaped electrode plate and provided with engaging projections on a circumferential portion of the electrode plate and engaging the engaging projections with the driver plate to integrate them. Alternatively, a method of manufacturing a variable capacitor, wherein at least one of the electrode plates is formed in a hoop shape and the other is assembled to one of the driver plate and the electrode plate formed in the hoop shape.