JPS60220521A - Vacuum bulb - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

[Technical background of the invention]

FIG. 1 shows the internal structure of a conventional vacuum valve. The openings at both ends of the insulating container 1 made of an insulating material are connected to end plates of 2 m,
A pair of electrodes 4a and 4b are provided facing each other in the vacuum vessel 3 closed by the electrodes 2b, respectively, at the ends of conductive rods 6 and 7 inserted into the vacuum vessel 3 through the end plates 2a and 2b. The electric current is turned on and off by moving one of the conductive rods 7 in the axial direction by an operation mechanism (not shown).

Here, a bellows 8 is provided between the end plate 2b and the conductive rod 7 in order to keep the inside of the vacuum container 3 airtight and to enable movement of the conductive rod 7 in the axial direction.

In order to prevent the metal vapor generated when the current is cut off from directly adhering to the inner surface of the insulating container 1, contaminating the inner surface of the insulating container 1 and impairing its insulation properties, it is usually made of metal such as copper or stainless steel. The completed shield 5 is a pair of electrodes 4g,
It is provided so as to reveal the area around 4b. Further, a bellows cover 9 is attached to the conductive rod 7 to protect the bellows from metal vapor 2.

[Problems with background technology]

The insulation inside the vacuum valve with this structure is the electrodes 4a and 4b.
, 8114m, 4b and the shield 5, and the shield 5 and the end plates 2a, 2b. However, with such a structure, an arc (metal vapor) generated between the two electrodes 4a and 4b
diffuses into the vacuum container, and repeatedly collides with and reflects on the shield 5 and bellows cover 9, adhering to and disappearing. In this process, the arc (metal vapor) that repeatedly collides and reflects may easily reach and adhere to the inner surface A of the insulating container 1, and as the current is repeatedly cut off, the inner surface of the insulating container 1 is gradually contaminated by the arc. There was a drawback that the insulation properties of the A section were deteriorated.

[Purpose of the invention]

An object of the present invention is to provide a vacuum valve that does not impair the insulation properties of the inner surface of an insulating container.

[Summary of the invention]

In the present invention, a conductive rod supporting an electrode is inserted, and at least one ring-shaped magnet magnetized in the same axial direction is attached to the conductive rod near the electrode on the atmosphere side.

[Embodiments of the invention]

The present invention will be described below with reference to the embodiment shown in FIG. The structure is basically the same as that shown in FIG. 1, and the same parts will be described with the same reference numerals. A vacuum container 3 in which openings at both ends of an insulating container 1 made of an insulating material are closed by end plates 2a and 2b.
Inside, a pair of electrodes 4a and 4b provided opposite each other are attached to the ends of a conductive rod 6.7 inserted into the vacuum vessel 3 through the end plates 2m and 2b, respectively. Ori,
The current is turned on and off by moving one of the conductive rods 7 in the axial direction by an operation mechanism (not shown).

Here, a bellows 8 is provided between the end plate 2b and the conductive rod 7 in order to keep the inside of the vacuum container 3 airtight and to enable movement of the conductor s7 in the axial direction.

A conductive rod 7 is inserted into the atmosphere-side inner surface of the bellows 8 near the electrode, and a ring-shaped magnet (ferromagnetic material) 10 magnetized in the axial direction is attached to the conductive rod 7. Here, ring-shaped magnet 10
The outer diameter of the electrode 4b is larger than that of the electrode 4b.

In order to prevent the metal vapor generated when the current is cut off from directly adhering to the inner surface of the insulating container 1, contaminating the inner surface of the insulating container 1 and impairing its insulation properties, a metal such as copper or stainless steel is usually used. A shield 5 made of a pair of electrodes 4a,
It is provided so as to cover the periphery of 4b. Further, a bellows cover 9 is attached to the conductive rod 7 to protect the bellows 8 from metal vapor.

In the vacuum valve having such a configuration, the ring-shaped magnet 1
0, an axial magnetic field with a distribution as shown in FIG. 3 is generated between the electrodes 4a and 4b. Both electrodes 4a,
In the arc (metal vapor) generated between 4b, the charged particles are restrained by this axial magnetic field. That is, charged particles are prevented from diffusing out of the electrode. Therefore, most of the arc is confined between the electrodes 4a and 4b. Therefore, the loss of the arc is reduced, the arc is stabilized, the arc voltage does not increase, and the generation of metal vapor itself is suppressed. Therefore, compared to the case without the ring-shaped magnet 10, the electrode 4a,
The amount of arc (metal vapor) generated between the electrodes 4b that diffuses outward from between the electrodes is extremely small.

FIG. 4 shows another embodiment. The central peripheral portion of the end plate 2a and one end of the cup-shaped end plate 11 are fixed and sealed, and the other end of the cup-shaped end plate 11 is fixed and sealed to the conductive rod 6. II of the atmosphere-side inner surface of the cup-shaped end plate 11! Conductive rod 6 very close
A ring-shaped magnet 12 is inserted into the conductive rod 6 and magnetized in the axial direction. The rest of the configuration is the same as in FIG. 2. The ring-shaped magnets 10 and 12 are magnetized in the same direction, and the magnetic field generated between the electrodes 4a and 4b is stronger than if only one of the ring-shaped magnets were attached. The effect of confining the arc is therefore increased.

[Effects of the Invention] According to the vacuum valve of the present invention, even if the current is repeatedly cut off, most of the arc generated between the electrodes is confined between the electrodes by the axial magnetic field generated between the electrodes by the ring-shaped magnet. The amount of arc that diffuses outward from between the electrodes is significantly reduced, the inner surface of the insulating container is not contaminated, and the initial insulation properties of the insulating container can be maintained for a long period of time.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the internal structure of a conventional vacuum valve, Fig. 2 is a sectional view showing the internal structure of an embodiment of the vacuum valve according to the present invention, and Fig. 3 is a sectional view showing the internal structure of a conventional vacuum valve. FIG. 4 is a cross-sectional view showing the internal structure of another embodiment of the vacuum valve according to the present invention. 3... Vacuum container, 4g, 4b... Electrode, 6.7...
Conductive rod, 10...Ring-shaped magnet (7317) Agent: Patent attorney Noriyuki Chika (and 1 other person) Fig. 2 Fig. 3

Claims (1)

[Claims] In a vacuum valve equipped with a pair of electrodes that are provided in a vacuum container so that they can be freely moved toward and away from each other, at least one ring-shaped magnet is fixed to a conductive rod that supports the electrodes on the atmosphere side near the electrodes. A vacuum valve featuring: