JPH0419790Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a small variable capacitor, and particularly to a small variable capacitor suitable for small radio receivers, radio cassette tape recorders, etc.

[Conventional technology]

FIG. 3 is a sectional view showing a conventional small variable capacitor, and FIG. 4 is a partially exploded perspective view of the same. In FIGS. 3 and 4, 1, 1, . . . indicate stator plates whose surfaces are coated with a dielectric material 1A, 2, 2, . They are arranged to form one stator group 3. 4, 5, and 6 are other stator groups having the same structure as stator group 3, respectively. The rotor plates 7, 7, . . . are arranged alternately with washers 8, 8, . . . and are inserted into a rotor shaft 9 having a threaded portion 9a at the tip, and fixed by screwing a nut 10 into the threaded portion 9A. has been done. 11, 12, 13, and 14 are rotor sections corresponding to the stator groups 3, 4, 5, and 6. 15 is a front board;
are provided with struts 15a and 15b that individually support the stator groups 3, 4, 5, and 6, respectively, and a bearing portion 15c through which the rotor shaft 9 is inserted. 16 is a rear board, which includes a front board 15.
Support columns 16a, 16b corresponding to the rotor shaft 9 and a hole 16c for supporting the rotor shaft 9 are provided. Rotor shaft 9 and stator groups 3, 4, 5,
6 is disposed so as to be sandwiched between the front board 15 and the rear board 16, and the stator groups 3, 4,
5 and 6, and the columns 15a and 1 of the front board 15.
It is assembled by a metal tongue 17 that is forcefully press-fitted into the housing 5b.

[Problem that the invention attempts to solve]

However, in such a conventional example, since the stator group is cantilever-supported only by the support portion A, there is a drawback that the free end B is likely to vibrate. In other words, when this small variable capacitor is incorporated into, for example, a radio receiver (not shown) and installed in the same cabinet as a speaker, the output of the high-output radio receivers that have become popular in recent years will be increased. As a result, the vibrations of the speaker are transmitted to the small variable capacitor via the cabinet. As a result, the free end B of the stator group may resonate in the audible frequency range, and this resonance may cause so-called howling from the speaker, resulting in a harsh sound.

The object of the present invention is to improve the drawbacks of the prior art and to provide a small variable capacitor suitable for small radio receivers, radio cassette tape recorders, etc. in particular.

[Means for solving problems]

Therefore, in the present invention, a rotor shaft is rotatably provided between a pair of substrates disposed facing each other, a rotor plate made of a thin metal plate is fixed to this rotor shaft, and a rotor shaft is provided between the substrates. The pillars installed in the are made of thin metal plates,
and a stator plate whose surface is covered with a dielectric material is thermally welded to the dielectric material protruding from the outer shape of the stator plate in a small variable capacitor fixedly installed opposite to the rotor plate with a small gap, In addition, an insulating member is provided that contacts the shape of the free end of the stator plate that is not fixed, and one end of the insulating member is held between supports provided on the substrate. This aims to achieve the above objectives.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Here, the same reference numerals are used for the same constituent members as in the conventional example described above.

1 and 2, stator groups 3, 4, 5, 6, rotor plates 7, 7,
The washers 8, 8, . . . , the rotor shaft 9, and the nut 10 are arranged in the same structure as in the conventional example described above, and detailed explanation thereof will be omitted. Reference numeral 18 denotes a front board, and the front board 18 has columns 1 that individually support the stator groups 3, 4, 5, and 6.
8a, 18b, and a bearing portion 18c through which the rotor shaft 9 is inserted. Reference numeral 19 denotes a rear board, which includes a column 1 corresponding to the front board 18.
9a, 19b, and a hole 19c for supporting the rotor shaft 9. In addition, the pillar 18
A, 18b, 19a, and 19b are each provided with two other wires (not shown). Reference numeral 20 denotes an insulating member that abuts along the shape of the free end B of the stator plate 1, and the insulating member 20
One end is disposed so as to be sandwiched between the front substrate 18 and the rear substrate 19 similarly to the rotor shaft 9 and the stator groups 3, 4, 5, and 6, and the rear substrate 19 Post 19 from the direction of
a, 19b, and a support hole provided at one end of the insulating member 20, and the stator groups 3, 4,
5 and 6, and the columns 18a and 1 of the front board 18.
It is assembled by a metal tongue 17 that is forcefully press-fitted into the part 8b. Here, in this embodiment, the support 19a of the rear board 19 is connected to the insulating member 20.
In order to sandwich the rear substrate 16 in the conventional example,
(See Figure 3)
It is formed to be shorter by the thickness of 0. In addition, by simultaneously welding the insulating member 20 and the dielectric material protruding from the outer shape of the stator plate 1 by heat, not only the stator plate 1 that is in contact with the insulating member 20 but also a plurality of heat-welded stators The same effect as when all the plates are in contact with the insulating member 20 can be obtained.

Note that FIGS. 5 and 6 are partial perspective views showing another embodiment, and the difference from the above embodiment is that the insulating member 20
They have the same configuration except for the difference in shape.

[Effect of idea]

As explained above, according to the present invention, the insulating member is thermally welded to the dielectric material protruding from the outer shape of the stator plate and comes into contact with the shape of the free end of the stator plate approximately along the shape of the unfixed free end. Since one end of the insulating member is sandwiched between the pillars provided on the board, vibration of not only the stator plate that comes into contact with the insulating member but also all the stator plates that are thermally welded to this stator plate is prevented. Therefore, it is possible to provide a high-performance compact variable capacitor that is highly effective in preventing howling.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a small variable capacitor showing an embodiment of the present invention, Fig. 2 is an exploded perspective view of a stator plate and an insulating member constituting the main parts, and Fig. 3 is a small variable capacitor showing a conventional example. FIG. 4 is an exploded perspective view with a portion of FIG. 3 omitted. 5 and 6 are perspective views of other embodiments of the insulating member, respectively. 1... Stator plate, 7... Rotor plate, 9... Rotor shaft, 18, 19...
...Substrate, 18a, 18b, 19a, 19b... Support column, 20... Insulating member.

Claims (1)

[Scope of utility model registration request] A rotor shaft is rotatably provided between a pair of opposing substrates, and a rotor plate made of a thin metal plate is fixed to the rotor shaft. In a small variable capacitor in which a stator plate made of a thin metal plate and whose surface is covered with a dielectric is fixed at one end opposite to a rotor plate with a small gap, the dielectric protrudes from the outer shape of the stator plate. An insulating member is provided which is thermally welded to the stator plate and abuts it roughly along the shape of the unfixed free end of the stator plate, and one end of this insulating member is held between supports provided on the substrate. A small variable capacitor with special features.