JPS631691B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a vacuum valve.

Vacuum valves contain fixed electrodes, movable electrodes, arc shields, etc. in a highly evacuated vacuum chamber. FIG. 1 shows a conventional vacuum valve, in which a fixed contact 4 provided on a movable shaft 3 corresponding to a movable contact 2 provided on a movable shaft 1 moves one end of an insulating tube 5 made of cylindrical glass or ceramic. The movable contact side end plate 7 to which the shaft 1 is attached via the bellows 6 is fixed, and the other is housed in a vacuum container to which the fixed contact side end plate 7 to which the fixed shaft 3 is fixed is fixed. Metal vapor generated by an arc during opening and closing is prevented from adhering to the inner surface of the insulating cylinder 5 and deteriorating the insulation, and the movable shaft 1 is smoothly moved linearly by the guide 10.

This structure has excellent insulation properties because the inside of the vacuum valve is maintained at a high degree of vacuum.
If the voltage is 6.6KV or less, an insulation distance of several mm is sufficient. However, since the outer periphery of the insulating cylinder 5 is in the atmosphere, the working voltage is determined by the creepage distance on the outside air surface in the axial direction.
For example, the value is 50mm for AC 3.3KV, AC 6.6KV
Therefore, a length of about 90mm is required. In this way, the size of the vacuum valve is determined by the length of the outside air surface in the axial direction of the insulating cylinder 5, so even if you try to improve economic efficiency by sharing the vacuum valve for 6.6KV AC circuit and the vacuum valve for 3.3KV AC circuit. , the larger vacuum valve for 6.6KV AC will be used, and the vacuum valve for 3.3KV AC will be used.
It is too large to be used for commercial purposes, and has disadvantages in terms of miniaturization and economy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vacuum valve which is miniaturized by improving the jacket insulation structure and can be commonly applied to different types of high voltages.

An embodiment of the present invention shown in the drawings will be described below. In FIG. 2, parts having the same functions as those in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted. In the vacuum container, the edge of a tip-shaped end plate 7 that fixes the bellows 6 to a ring-shaped flat insulating plate 11 such as glass or ceramic is fixed to the fixed contact side end 8, and the outer side of the end plate 7 is made of an elastic material. For example, it is covered with an insulating cap 12 made of synthetic rubber, and an insulating plate 1 is placed in the inner recess 12a.
1, and the joint portion of the insulating plate 11 and the end plate 7 and the recess 12a of the insulating cap 12 are filled with an insulator 13 of liquid or adhesive, such as silicone grease, and bonded to completely insulate the interface. I have to.

Next, the effect will be explained. The insulation between poles on the atmosphere side of the vacuum valve is the sum of the radial creepage distance of the bottom of the insulation cap 12 on the atmosphere side, the axial creepage distance on the atmosphere side, and the atmosphere side creepage distance of the insulating plate 11, and the surface creepage. The effective distance has become very long. Furthermore, since the joint surfaces of the insulating plate 11 and the end plate 7 with the insulating cap 12 are sealed with an insulating material 13, complete insulation is maintained without any leakage current.

As described above, according to the present invention, in a vacuum valve, the edge of the tip-shaped end plate that fixes the movable shaft via the bellows is fixed to the insulating plate that fixes the fixed shaft, and the outer side of the end plate and the insulating plate are fixed. The edge is covered with an elastic insulating cap, and the part where the insulating plate and end plate join is filled with liquid or adhesive insulator, so the insulation between poles is large despite the small size, making it suitable for use in, for example, 600V circuits. The vacuum valve can be upgraded for use in 6.6KV circuits. Therefore, since the same vacuum valve can be used for various circuit voltages, it is possible to unify vacuum valves and mass-produce them, which has excellent effects such as being extremely economical.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional vacuum valve, and FIG. 2 is a longitudinal sectional view showing an embodiment of the vacuum valve of the present invention. 1...Movable axis, 2...Movable contact, 3...Fixed axis, 4...
Fixed contact, 6... bellows, 7... end plate, 8... end plate,
9... Arc shield, 10... Guide, 11... Insulating plate, 12... Insulating cap, 13... Insulator.

Claims (1)

[Claims] 1. A flat insulating plate to which a fixed shaft with a fixed contact is fixed, and a movable shaft whose edge is fixed to this insulating plate and has a movable contact inside that contacts and separates from the fixed contact, attached via a bellows and vacuum-sealed. an elastic insulating cap that covers the outside of the end plate and the edge of the insulating plate; and a liquid or adhesive that fills the insulating cap, the insulating plate, and the joining portion of the end plate. A vacuum valve made of a flexible insulator.