JPH0132736Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small variable capacitor that changes capacitance by alternately engaging a stator plate whose surface is covered with a dielectric and a rotating rotor plate.

A small variable capacitor has a stator plate whose surface is covered with a dielectric material and a rotor plate that is fixed to the rotor shaft and rotates, and the capacitance is changed by changing the opposing area. I have to. In addition, the stator plate and rotor plate are provided in multiple groups, and each group has an AM antenna input stage, an FM antenna input stage,
It is designed to set the capacitance in the FMOSC stage and other sections.

However, in the conventional small variable capacitor of this type, the stator plate was supported on a cantilever, and therefore had the disadvantage of being susceptible to vibration. In other words, this small variable capacitor is installed in the same cabinet as the speaker in a set of audio equipment, etc., and in the high-output set that has become popular in recent years, by increasing the output, the vibrations of the speaker can be reduced. It is transmitted to a small variable capacitor via. As a result, the stator plate may resonate in the audible frequency range, and howling may occur from the speaker. In order to prevent this phenomenon, it is best to make the gap between the stator plate and the rotor plate as narrow as possible, but if this gap is made too narrow, the rotational resistance of the rotor shaft increases, making it difficult to operate.

The present invention was developed by focusing on the above-mentioned conventional problems, and is a compact design that can effectively prevent the above-mentioned howling with a simple structure and without affecting the rotational resistance of the rotor shaft. The purpose is to provide variable capacitors.

The small variable capacitor according to the present invention has a pair of substrates inside which are provided with a rotor plate and a stator plate, and has support protrusions inside facing each other, and the support protrusions are brought into contact with and supported by the stator plate, thereby suppressing the vibration of the stator plate. This was prevented.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is a sectional view of a small variable capacitor, Figure 2 is an enlarged sectional view showing the stator plate support state, and Figure 3 is an enlarged sectional view of the small variable capacitor.
The figure is a plan view showing a stator plate and a rotor plate.

Reference numeral 1 in the figure is a lower substrate, and 2 is an upper substrate. A columnar support portion 1 is provided on the upper surface of the lower substrate 1.
a, 1b (actually there are four, but only two are shown)
are integrally molded. Further, columnar support portions 2a and 2b (also actually 4
(a book) are molded in one piece. Lower board 1
In a state where the upper substrate 2 and the upper substrate 2 are combined, the lower support portion and the upper support portion face each other in combinations of 1a and 2a and 1b and 2b. A plurality of stator plates 3 are held between these opposing parts. A stator washer 4 is interposed between each stator plate 3 to maintain the spacing between the stator plates 3. The stator plate 3 and stator washer 4 are integrated by laser welding, soldering, or the like. Furthermore, metal struts are forcefully press-fitted into the opposing support portions 1a and 2a, the stator plate 3, and the stator washer 4. The same applies to the other supporting parts 1b and 2b.
This metal support 5 includes a lower substrate 1, an upper substrate 2, a stator plate 3, and a stator washer 4.
The central portion of the metal support 5 is electrically connected to the stator plate 3, and the lower end 5a functions as a stator side terminal.

The planar shape of the stator plate 3 is shown in FIG. This stator plate 3 is formed into a triangular shape by a thin plate of metal such as aluminum. The base 3a of the stator plate 3 is in the shape of a disc having the same diameter as the supporting parts 1a, 1b, 2a, 2b and the stator washer 4, and the base 3a is
A small hole 3 for press-fitting the metal support 5 into the center of the
b is drilled. Further, a recess 3c is formed on one side of the triangular portion. This triangular portion is covered with a dielectric material 6 such as polyethylene film.

Further, a dielectric lead 7 is formed on the upper surface of the lower substrate 1, and the end of this lead 7 extends outside the board and is bent, and the rotor side terminal 7a is formed by this end. There is. A rotor shaft 8 is rotatably supported at the center of the lower substrate 1. This rotor shaft 8 is inserted into the lower board 1 from below, and a washer 9 and a stopper 10 are inserted in this order from above the lower board 1, and this stopper 10 is inserted into the upper surface of the lower board 1 by means such as press fitting. Fixed. As a result, the rotor shaft 8 is electrically connected to the lead 7. In addition, the rotor shaft 8 has
A rotor plate 11 and a rotor washer 12 are laminated in order and extrapolated, and a nut 13 is attached to the top.
is screwed and fixed. Further, the upper end of the rotor shaft 8 is supported by a leaf spring 14 provided on the lower surface of the upper substrate 2. This rotor plate 1
1 is made of a thin metal plate such as aluminum, and the third
It is formed into a semicircular shape as shown in the figure. When the small variable capacitor is assembled, the rotor plate 11 faces the stator plate 3 at a very small distance, and the concave portion 3c of the stator plate 3 is in contact with and supported by the peripheral portion of the rotor washer 12. Become.

Further, a support protrusion 15 is integrally provided on the upper surface of the lower substrate 1, and this support protrusion 15 allows
The stator plate 3 on the lower substrate side is supported. That is, the support protrusion 15 comes into contact with one edge of the stator plate 3, and the stator plate 3
is supported in a slightly elastically deformed state (in the figure, lifted from below) (see Fig. 3).

Next, the operation and effects of the present invention with the above configuration will be explained.

The capacitance is set by rotating the rotor shaft 8. That is, when the rotor shaft 8 is rotated, as shown in FIG. 3, the opposing area between the rotor plate 11 and the stator plate 3 changes, and the capacitance between the plates 3 and 11 changes. In the embodiment shown in FIG. 1, two groups of stator plates 3 and two groups of rotor plates 11 are provided, and the capacitance of one group is between the rotor side terminal 7a on the left side in the figure and the lower end 5a of the metal support 5. It can be taken out in between. Also, the capacitance of the other group is
It can be taken out between the rotor side terminal 7a and the metal support 5a on the right side in the figure. AM in each group
The capacitance is set for each section such as the antenna input stage and FM antenna input stage.

Furthermore, since the stator plate 3 on the lower substrate 1 side is held down by the support protrusion 15, even if vibration occurs due to the output of a large-capacity speaker, the supported stator plate 3 will not vibrate due to resonance. Therefore, howling phenomenon due to vibration is less likely to occur.

In the illustrated embodiment, a support protrusion 15 is provided on the upper surface of the lower substrate 1, but a similar support protrusion is also provided on the lower surface of the upper substrate 2 to support the stator plate 3 at the top of the figure. Good too. Further, protrusions extending laterally from the support parts 1b and 2a may be provided to support the stator plate 3 located at the center.

As described above, according to the present invention, the following effects can be achieved.

(1) Support protrusions are provided between the substrates and the stator plate is supported by the support protrusions, so the stator plate does not vibrate due to the output of the speaker, etc., and howling phenomenon is less likely to occur.

(2) Support protrusions are formed on the substrate or on the support part integrated therewith, and the stator plate is supported by the support protrusions, so the overall structure and assembly work can be simplified without changing from conventional methods.

(3) The gap between the stator plate and rotor plate remains the same as before.
The rotational resistance of the rotor shaft does not increase, and the operability does not deteriorate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a small variable capacitor according to the present invention, FIG. 2 is an enlarged sectional view showing a support portion of a stator plate, and FIG. 3 is a plan view of a rotor plate and a stator plate. 1, 2...Substrate, 1a, 1b, 2a, 2b...
Support part, 3... Stator plate, 6... Dielectric, 8... Rotor shaft, 11... Rotor plate, 15... Support protrusion.

Claims (1)

[Scope of utility model registration request] A rotor shaft is rotatably provided between a pair of opposing boards, a rotor plate made of a thin metal plate is fixed to this rotor shaft, and a support part provided between the boards is , a stator plate made of a thin metal plate and whose surface is covered with a dielectric is fixedly disposed opposite to the rotor plate with a minute gap between the two substrates; A small variable capacitor characterized by being provided with a contacting support protrusion.