JPS6127169Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a small variable capacitor, in which each stator plate group is fitted at two points to a stator shaft for taking out the potential and a specially provided pillar to suppress the generation of support stray capacitance, miniaturize the structure, and The purpose is to provide a small variable capacitor that can be stabilized.

Examples of conventional small variable capacitors include those shown in FIGS. 1A and 1B. In the figure, a small variable capacitor 1 supports a rotor shaft 3 on a variable capacitor board 2, and has four stator shafts 4 for taking out potentials implanted therein.
For example, four sets of rotor plate groups 5a to 5d that are fitted and fixed to the rotor shaft 3 and four sets of stator plate groups 6a to 6d that are fitted and fixed to the stator shaft 4 each have opposing areas as the rotor shaft 3 rotates. The stator plates 6a to 6d each have a pair of support holes connected to a pair of left and right stator shafts 4 (4a, 4a,
4d) were sequentially and alternately fitted and supported at two points. In the figure, 7 is the upper plate and 8 is the case. Therefore, according to the above configuration, for example, two sets of stator plate groups 6b and 6d are stacked and supported on the pair of stator shafts 4b (4b ₁ , 4b ₂ ) on the right side in the figure, and the lower stator The plate group 6b is one stator shaft 4
It is electrically fitted to the stator shaft 4b ₁ to extract the potential, and is fitted to the other stator shaft 4b ₂ via an insulating washer or the like,
On the other hand, the upper stator plate group 6d is electrically fitted to the stator shaft 4b ₂ so that a potential is taken out from the stator shaft 4b _{1 .}
It was fitted with an insulating washer etc.

However, according to the above conventional example, a stray capacitance is created between the lower stator plate group 6b and the stator shaft _4b2 via the insulating washer, and similarly, a stray capacitance is created between the upper stator plate group 6d and the stator shaft _4b1 . Therefore, the minimum capacitance Cmin value of the entire variable capacitor tends to increase due to the stray capacitance, and the maximum capacitance Cmax value must also be increased in order to obtain a predetermined variable capacitance, which has the disadvantage of increasing the size of the variable capacitor configuration. It was hot.

Another conventional example is one in which each stator plate group is electrically fitted and supported on an individual stator shaft in order to eliminate the above-mentioned drawback of stray capacity.
According to this, it is difficult to position the stator plate in the radial direction when assembling the stator plate, and the support condition is unstable, which tends to cause howling, and there are problems in terms of performance.

The present invention eliminates the above-mentioned drawbacks and will be described below with reference to the drawings.

FIGS. 2A to 2C are side views of one embodiment of the small variable capacitor according to the present invention, and partial cross-sectional views taken along lines B-B and C-C in the figures, and FIGS. , B are given the same reference numerals and their explanations will be omitted. In the figure, a pair of metal stator shafts 12a and 12b are implanted in the variable capacitor board 2 of the small variable capacitor 11 in FIG. However, a pair of stator shafts 12b (1
2b ₁ , 12b ₂ ) The nearby configuration will be explained. (The same applies to the configuration near the pair of stator shafts 12a.) The pair of stator shafts 12 of the variable capacitor board 2
At a predetermined position between b ₁ and 12b ₂ are an insulating column 13 of a small height and a small diameter shaft 14 each having a small diameter portion 13a.
It is integrally provided with an insulating support column 14 having a large height and projecting therefrom.

15 and 16 are stator plate groups, each consisting of a plurality of stator plates, and a pair of stator shafts 12b ₁ and 12
_B2 is laminated and arranged as described above. Stator plate group 1
5 has a pair of support holes 15a and 15b, and a second
As shown in Figure B, the hole 15a is connected to one stator shaft 12b ₁
The other hole 15b is fitted into the small diameter portion 13a of the support column 13 having a small height to provide two-point fitting support. Similarly, stator plate group 16
has a pair of support holes 16a and 16b, and as shown in _FIG . The other hole 16b is fitted into the small diameter portion 14a of the pillar 14 having a large height, and supported by two-point fitting.

Therefore, in the stator plate group 15, one hole 15a portion is electrically supported by one stator shaft 12b ₁ , and the other hole 15b portion is supported by the insulating support column 13, and is separated by a predetermined distance from the stator shaft 12b ₂ . , almost no stray capacity occurs between the stator plate group 15 and the stator shaft _12b2 . The same applies to the stator plate group 16. Therefore, Cmin of the entire variable capacitor 11
Since the value can be suppressed to a small value, the Cmax value can also be suppressed, and the variable capacitor configuration can be made smaller.

Furthermore, since the stator plate groups 15 and 16 are supported by two-point fitting, positioning is more stable and howling is less likely to occur compared to one-point fitting support.

The above-mentioned supports 13 and 14 may be made by implanting metal pins into the variable capacitor board 2, but since there is a possibility that some stray capacitance may occur between them and the stator shafts 12b ₂ and 12b ₁ , respectively, it is better to use insulating ones. desirable.

In the above embodiment, holes 15a, 15b and 16
a, 16b are not necessarily limited to circular holes, and in some cases, a part of the circular hole may be the stator plate 15, 1.
It may have a shape with a notch on the outer end surface of 6,
According to this, fitting to the shafts 12b ₁ , 12b ₂ , 13, and 14 becomes easy.

As described above, in the miniature variable capacitor of the present invention, a rotor shaft having a rotor plate group is supported on a substantially rectangular variable capacitor board, and a stator shaft for potential extraction having a stator plate group is provided protruding from the four corners of the variable capacitor board. In this miniature variable capacitor, a support post is provided protruding from the variable capacitor board at a position between the stator shafts, and one support hole of the stator plate group is fitted onto the stator shaft and another support hole is fitted onto the support post to support the stator plate group. This eliminates the need for a two-point fit of the stator plate group to a pair of stator shafts as in the conventional variable capacitor. In contrast to the conventional method in which a stray capacitance is generated by electrically connecting the stator plate group to one stator shaft, the stator plate group is electrically connected to one stator shaft and is spaced apart from the other stator shaft by a predetermined distance, so that almost no stray capacitance is generated between the other stator shaft and the stator plate group. Therefore, the maximum water capacity Cmin value and the maximum capacity Cmax value can be kept relatively small, and the overall structure can be made compact. Furthermore, since the stator plate group is connected to the stator shaft and the support at two points, positioning is stable and assembly is easy, and howling can be suppressed and performance can be improved. Thus, a compact and high-quality 4-phase motor can be manufactured.
This has the advantage that it is possible to realize a variable capacitor having a four-unit structure with four sets of capacitor parts.

[Brief explanation of the drawing]

1A and 1B are a longitudinal section and a plan view, respectively, of a conventional example of a small variable capacitor, and FIGS.
FIG. 3 is a partial cross-sectional view taken along the middle BB line and the CC line. 1, 11...Small variable capacitor, 2...Variable capacitor board, 3...Rotor shaft, 4 (4a, 4b), 4b ₁ ,
4b ₂ , 12 (12a, 12b), 12b ₁ , 12b ₂
... Stator shaft, 5a to 5d ... Rotor plate group, 6
a to 6d, 15, 16... stator plate group, 7...
Upper plate, 13, 14...support.

Claims (1)

[Scope of utility model registration request] A small variable capacitor in which a rotor shaft having a rotor plate group is supported on a substantially rectangular variable capacitor substrate, and a stator shaft for taking out potential having a stator plate group is protruded from the four corners of the variable capacitor substrate. A structure in which a strut is provided protrudingly between the stator shafts, one support hole of the stator plate group is fitted to the stator shaft, and another support hole is fitted to the strut to support the stator plate group. A small variable capacitor.