JPH07288218A - Vacuum capacitor - Google Patents

Abstract

PURPOSE:To use the body which has the same constitution as a vacuum capacitor main body over the wide/narrow adjustment range use. CONSTITUTION:A removable screw member 1 is provided on a movable lead 18' and an electrostatic capacitance adjusting screw 2 is screwed into the screw member 1. The movable lead 18' is vertically moved by rotation drive of an adjustment screw 2, and electrostatic capacitance is adjusted. The screw members 1 with the screw pitches applicable to the purposes such as rough and fine adjustment are prepared and applicable screw to the use is selected and used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum capacitor used in an oscillation circuit of a high power transmitter, a high frequency power source for semiconductor manufacturing equipment, a tank circuit of an induction heating device, or the like.

[0002]

2. Description of the Related Art FIG. 2 is a sectional structural view of a conventional general variable-type vacuum capacitor. For example, a cylindrical portion is formed by joining copper cylindrical tubes 11a and 11b to both ends of an insulating cylinder 12 made of ceramic or the like. Then, the cylindrical portion is closed by the fixed-side end plate 13 and the movable-side plate 14 to form the vacuum container 10 that houses the condenser portion.

The fixed side end plate 13 also serves as an electrode mounting conductor, and inside thereof, a plurality of cylindrical electrode plates F having different diameters (radii) are provided.
₁ , F ₂ ... F _n are attached concentrically at regular intervals to form a fixed electrode 15, and the fixed electrode 15 is formed.
Of the cylindrical electrode plates M ₁ , M ₂ ... Mn having different inner diameters so that they can be inserted / removed in the gaps between the electrode plates in a non-contact state.
The movable electrode 16 which is an electrode mounting conductor.
Is formed.

A movable lead 18 'is provided on the movable conductor 18, and the movable lead 18' is rotatably supported by a bearing 17 provided through the movable end plate 14 so as to be vertically movable. The movable electrode 16 is moved in the axial direction from the outside of the vacuum container by the capacitance adjusting means. Reference numeral 19 denotes a bellows, one end of which is brazed to the movable end plate 14 and the bearing 17, and the other end of which is brazed to the movable lead 18 'or the movable conductor 18, and the sliding portion between the bearing 17 and the movable lead 18' and the bearing. The penetrating portion of the movable end plate 14 of 17 is covered so that the movable lead can move up and down while preventing vacuum leakage.

The entire cylindrical portion of the vacuum container 10 may be formed of an insulating cylinder made of ceramic or the like. The point is that the fixed electrode and the movable electrode may be electrically insulated.

The vacuum capacitor body is constructed as described above, but this type of vacuum capacitor is provided with a capacitance adjusting means for adjusting the capacitance. Reference numeral 20 denotes this capacitance adjusting means, and the capacitance adjusting means 20 is
It is composed of a capacitance adjusting screw receiving portion 21 having one end side attached to the bearing 17, and a capacitance adjusting screw 23 rotatably attached to the other end side of the screw receiving portion 21 via a thrust bearing 22. ing. The screw part 23a of the capacitance adjusting screw 23 is screwed into the screw part 18a provided on the inner diameter of the movable lead 18 ', and the operating part 23b is moved manually or by rotating the movable lead 18' via the movable lead 18 '. The electrode 16 is moved up and down.

When the electrostatic capacitance of the vacuum capacitor thus constructed is adjusted, the movable electrode and the fixed electrode are energized and the operating portion 23b of the electrostatic capacitance adjusting screw 23 is rotated to move the movable lead 18. ′ Is moved up and down to change the facing area between the fixed electrode 15 and the movable electrode 16 to continuously change the value of the electrostatic capacitance generated between the electrodes 15 and 16.

[0008]

As described above, the capacitance of the vacuum capacitor is adjusted by moving the movable lead up and down, and its displacement is adjusted by the capacitance adjusting screw 23 and the movable lead screwed to this. It is determined depending on the pitch of the threaded portion 18a of 18 '.

On the other hand, this type of capacitor is used for adjusting the impedance of a high frequency power source for semiconductor manufacturing equipment, but when the impedance adjusting range is narrow, the capacitance adjusting screw 23 and the screw of the movable lead 18 'are used. It is necessary to reduce the pitch of the parts to improve the capacitance resolution.

On the contrary, the impedance adjustment range is wide,
In addition, when it is necessary to change at high speed, it is necessary to increase the pitch of the adjusting screw.

Increasing the pitch of the adjusting screw has a small diameter of the movable lead, and there is a limit to increasing the screw pitch. Alternatively, we proposed a trapezoidal screw whose capacitance can be changed significantly with a small number of rotations.
(Japanese Patent Application No. 4-236596) However, it is necessary to provide the movable lead with a screw hole having a pitch corresponding to the pitch of the capacitance adjusting screw. Different screw holes were screwed. Therefore, even if the vacuum capacitor body has the same structure, it becomes a different model, and it is necessary to prepare many models for different purposes.

In view of the above points, the present invention provides a vacuum capacitor that can be adapted to all applications by changing the moving means of the movable electrode for adjusting the capacitance without preparing a model of the vacuum capacitor body for each application. The purpose is to do.

[0013]

Means for Solving the Problems In the present invention, means for solving the above-mentioned problems is to install a plurality of concentric cylindrical electrode plates having different diameters concentrically on an electrode mounting conductor in a vacuum container. A fixed electrode formed and a movable electrode formed by concentrically attaching a plurality of cylindrical electrode plates having different diameters to each other so that they can be inserted / removed between the cylindrical electrode plates of the fixed electrode in a non-contact state. A movable lead for moving the movable electrode from the outside of the vacuum container in the axial direction of the cylindrical electrode plate, and the moving means for moving the movable electrode includes a screw portion provided on the inner circumference of the movable lead and the screw portion. In a vacuum capacitor formed by an electrostatic capacity adjusting screw that is screwed into and is rotationally driven, the screw part of the moving means is attached separately from the movable lead, and is constituted by a removable screw member,
A screw having a screw pitch or a screw shape that matches the application is prepared for the screw and the screw member forming the moving means, and is selectively used.

Further, it is preferable that the screw member of the moving means of the movable electrode is fitted and fixed in a fitting hole provided in the movable lead, and the capacitance adjusting screw is rotatably attached to the adjusting screw receiving portion. It is what

[0015]

As described above, according to the present invention, the screw member constituting the moving means for moving the movable electrode and the pair of the capacitance adjusting screw screwed to the screw member are provided with a dense screw pitch or a coarse screw pitch. In addition, a multi-thread screw or a trapezoidal screw is prepared in advance, and a screw suitable for the purpose is selected, and the screw member is attached and fixed to the movable lead. Therefore, even if the same vacuum capacitor body is used, it is possible to obtain a vacuum capacitor whose capacitance can be adjusted to suit the application.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below based on an embodiment shown in the drawings. FIG. 1 is a sectional view for explaining the capacitance adjusting means of an embodiment of the present invention. 2 is different from FIG. 2 in that the movable lead 18 'is not provided with a screw portion, but the screw portion is provided on a screw member 1 which is separate from the movable lead 18', and the screw member 1 is attached to the movable lead 18 '. The point is that it is detachable. The screw portion 2a of the capacitance adjusting screw 2 is screwed into the screw hole of the screw member 1, and the movable lead 18 'is driven by the rotation driving of the capacitance adjusting screw 2.
Are moved up and down. Reference numeral 3 denotes an adjusting screw receiving portion, which is formed of a cylindrical shape or a frame plate, one end side of which is attached to the bearing 17 by an attaching means such as a screw, and the capacitance adjusting screw 2 through the thrust bearing 4 at the center of the other end side. The operation portion 2b of is attached rotatably.

The moving means for moving the movable electrode is formed by a screw member 1 and an adjusting screw 2 screwed into the screw member 1. The screw member 1 and the adjusting screw 2 have a pair of screw pitches or screw shapes depending on the intended use. prepare. That is, the coarse screw pitch,
Prepare a dense, multi-start screw or trapezoidal screw, etc., select from among them according to the application, and attach the screw member to the movable lead and fix it.

By selecting the screw member and the capacitance adjusting screw to be screwed with the screw member in this way, the vacuum capacitor main body having the same structure can be used according to the purpose.

To attach the screw member 1 to the movable lead 18 ', a fitting hole is formed at the end of the movable lead, and the screw member 1 is fitted into this fitting hole to fix a screw or the like from the outer periphery. It is fixed by means, or the movable lead and the screw member are screwed together and fixed by the fixing means.

The capacitance adjusting screw may be detachably attached to the adjusting screw receiving portion 3, or may be integrally formed with the adjusting screw receiving portion.

[0021]

As described above, according to the present invention, the moving means for moving the movable electrode is formed separately from the vacuum capacitor body, and the screw pitch of the screw member and the capacitance adjusting screw screwed to the screw member is formed. Or, use different shapes (purpose)
Since it is separately prepared in advance and is selected and used according to the application, the same vacuum capacitor body can be used, and the cost increase due to the increase in conventional models can be reduced. In addition, the cost of the vacuum capacitor can be reduced in combination with the fact that it can be applied to various purposes only by attaching the screw member.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an embodiment of the present invention.

FIG. 2 is a basic configuration diagram of a conventional vacuum capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Screw member 2 ... Capacitance adjustment screw 3 ... Adjustment screw receiving part 4 ... Thrust bearing 15 ... Fixed electrode 16 ... Movable electrode 18 '... Movable lead

Claims (2)

[Claims] 1. A fixed electrode formed by concentrically mounting a plurality of concentric cylindrical electrode plates of different diameters in an electrode mounting conductor in a vacuum container, and a non-between the cylindrical electrode plates of the fixed electrode. A movable electrode formed by concentrically attaching a plurality of cylindrical electrode plates having different diameters to an electrode mounting conductor so that the movable electrode can be inserted and removed in a contact state, and the movable electrode is provided from the outside of the vacuum container in the axial direction of the cylindrical electrode plate. The moving means for moving the movable electrode is a vacuum formed by a screw portion provided on the inner circumference of the movable lead and a capacitance adjusting screw screwed into the screw portion and driven to rotate. In the capacitor, the screw part of the moving means is separated from the movable lead to be attached and detached, and the vacuum capacitor is constituted. 2. The screw member of the moving means for moving the movable electrode comprises:
2. The vacuum capacitor according to claim 1, wherein the capacitance adjusting screw is fitted and fixed in a fitting hole provided in the movable lead, and the capacitance adjusting screw is rotatably attached to an adjusting screw receiver.