JPH06275175A - Vacuum valve - Google Patents

Abstract

PURPOSE:To provide a small-sized vacuum valve with simple structure which can apply a vertical magnetic field between electrode bodies by a permanent magnet. CONSTITUTION:In stead of a permanent magnet 11 which loses its magnetic filed when exposed to high temperature, a magnet material 11a is housed in a vessel 6, and the vacuum vessel 6 is formed under high temperature atmosphere. Thereafter, the vacuum vessel 6 is arranged in a magnetizing device 50 to impart the magnetic field. The magnetic material 11a is thus magnetized to form the permanent magnet 11, and a vertical magnetic field can be applied between both electrode bodies 4, 5. Thus, a complicated structure to prevent the magnetic field from being lost when exposed to high temperature is not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve used in a vacuum circuit breaker.

[0002]

2. Description of the Related Art A vacuum valve is a device in which a pair of fixed and movable electrode bodies are arranged so that they can come into contact with and separate from each other, and one movable electrode body is separated from the other fixed electrode body to cut off electrical connection. Therefore, in order to increase the breakdown voltage between the contacts, both electrode bodies are arranged in a vacuum container in a high vacuum state. It is known that when a current is cut off, a vertical magnetic field is applied in parallel with the arc generated between the two electrode bodies to improve the breaking capacity. As a specific structure for this, a permanent magnet is used. Is disclosed in JP-A-2-278627.

Here, in the manufacturing process of the vacuum valve, after disposing members such as electrode bodies to be arranged in the vacuum valve, the entire vacuum valve is charged into a heating furnace and heated in a heating atmosphere. Assembly work and degassing work are being performed. Therefore, if a permanent magnet is loaded in advance, this heating causes the permanent magnet to lose its magnetic force, making it impossible to apply a longitudinal magnetic field between both electrodes. Therefore, in this conventional technique, each electrode body is formed in a cylindrical shape with a bottom, and the permanent magnet is inserted from the hollow portion communicating with the outside of the vacuum container after the vacuum container is manufactured.

[0004]

However, in this prior art, the bottomed tubular electrode body must have a large diameter in order to withstand the impact load during operation, etc. Fixing means is required to fix the magnet in the hollow part,
The structure of the fixing means is complicated and the assembling work is troublesome. Therefore, an object of the present invention is to make a vacuum valve, which has a simple structure and a small size, capable of applying a longitudinal magnetic field between electrode bodies by a permanent magnet.

[0005]

According to the present invention, there is provided a vacuum valve in which a permanent magnet for applying a longitudinal magnetic field is provided between a pair of electrode bodies which are arranged facing each other in a vacuum container and can be separated from each other. The vacuum valve is characterized in that the permanent magnet is magnetized by a magnetic field applied from the outside of the vacuum container after vacuum-sealing the inside of the vacuum container.

[0006]

The permanent magnet loses its magnetic force when exposed to a high temperature. However, in the present invention, instead of the permanent magnet, the magnet material is housed in a vacuum container and exposed to a high temperature state at the stage of the magnet material. After that, a magnetic field is applied from the outside of the vacuum container to magnetize the magnet material to form a permanent magnet, so that a longitudinal magnetic field can be applied between the two electrode bodies by the permanent magnet arranged in the vacuum container. . Then, due to this longitudinal magnetic field, the arc generated when the current is opened and closed is dispersed between the electrodes. Further, since the magnet material can be arranged in advance before being made into a vacuum container, a complicated structure for fixing the magnet material is not required.

[0007]

According to the present invention, after the permanent magnet material is vacuum-sealed in the vacuum container without requiring a fixing means having a complicated structure as compared with the case where the permanent magnet is fixed to the vacuum container, Since it is magnetized by a magnetic field applied from the outside of the vacuum container, the structure of the vacuum valve that can apply a vertical magnetic field between the electrode bodies can be simple and small.

[0008]

【Example】

<Embodiment 1> Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS.
It will be described in detail based on. As shown in FIG. 1, the vacuum valve has metal lids 2 and 3 hermetically welded to both openings of a cylindrical insulating container 1 made of ceramics such as porcelain by brazing. A pair of electrode bodies 4, 5 are airtightly attached through the metal lids 2, 3 to form a vacuum container 6 having a high degree of vacuum. The electrode body 4 is fixed to the metal lid 2, while the electrode body 5 is attached to the metal lid 3 via a bellows 7 so as to be able to move back and forth on the axial extension line of the electrode body 4.
Further, large-diameter electrode plates 8 and 9 are respectively provided at the tips of the two electrode bodies 4 and 5, and the two electrode plates 8 and 9 are arranged facing each other so that they can come into contact with and separate from each other.

Here, the tip ends of the electrode bodies 4 and 5 have substantially the same configuration. The electrode body 5 on the movable side will be described below. In FIG. 2, the permanent magnet 1 is attached to the tip of the electrode body 5.
An accommodating space 12 for accommodating 1 is formed in a hollow cylindrical shape, and an electrode plate 9 is welded to the tip of the electrode body 5 by a braze 13. A disk-shaped magnetic body 15 is accommodated in the recess 14 provided in the electrode plate 9, and the cover plate 17 is also welded to the recess 14 by brazing to fix the permanent magnet 11 and the magnetic body 15. ing. A cushion 18 made of metal foil is laid on the bottom surface of the accommodation space 12, and the permanent magnet 11 and the magnetic body 15 are arranged so as to be sufficiently in contact with each other. A shield 10 is provided around both electrode plates 8 and 9 to prevent metal vapor generated from both electrode plates 8 and 9 from adhering to the inner wall of the insulating container 1 when the current is switched.

In the manufacturing process of the vacuum valve having this structure, the magnet material 11a is used instead of the permanent magnet 11. Then, the metal lids 2 and 3 are brazed into a vacuum container 6 in a heating furnace (not shown) in a predetermined vacuum state. Then, after a predetermined vacuum state, the magnet material 11a
Is magnetized. The magnetizing process is performed by accommodating the magnetizing device 50 in the magnetizing device 50 as shown in FIG. This magnetizing device 5
Reference numeral 0 denotes an electromagnetic coil 52 wound on the outer surface of a cylindrical case 51 into which the insulating container 1 of the vacuum valve can be inserted. By turning on a switch 53, a current from a DC power source 54 flows through the electromagnetic coil 52. Along with this, a strong magnetic field is applied to the electrode bodies 4 and 5 in the case 51. A support plate 55 is provided in the case 51, and both electrode plates 8 and 9 of the inserted vacuum valve are arranged at the central position of the electromagnetic coil 52.

By this magnetizing treatment, the two magnet materials 11a arranged in the case 51 are exposed to a strong magnetic field in one direction to become the permanent magnets 11 having opposite polarities and facing each other. The applicant showed good magnetism when a samarium-cobalt-based or neodymium-iron-boron-based anisotropic magnet material as the magnet material 11a was heated to 860 ° C. and then magnetized.

In the first embodiment, the electrode plates 4 and 5 are welded with the electrode plates 8 and 9, and then the cushion 18 and the magnet material 11a are used.
The magnetic material 11a can be fixed by loading the magnetic material 15 and covering it with the cover plate 17. Further, since the permanent magnet 11 is provided at the tips of the electrode bodies 4 and 5, and the permanent magnet 11 and the magnetic body 15 are provided in the electrode plates 8 and 9, the permanent magnet 11 is fixed as in the conventional example. No complicated fixing means is required, and the electrode can have a simple structure. Further, it is not necessary to make the electrode bodies 4, 5 cylindrical in order to insert the permanent magnet 11, and the electrode bodies 4, 5 having a small diameter can be inserted.
It can be 5.

Further, in the first embodiment, since the cushion 18 made of a metal foil is provided on the back surface of the permanent magnet 11 to bring the permanent magnet 11 and the magnetic body 15 into pressure contact with each other, vibration caused by the operation of the vacuum valve is performed. The shock is relieved and the permanent magnet 11 is prevented from being damaged. As a result, the permanent magnet 11
As a result, a stable magnetic field can be maintained between the electrode plates 8 and 9.

<Second Embodiment> In the first embodiment, the permanent magnet 11 is fixed in the electrode bodies 4 and 5, but in the second embodiment, the permanent magnet 11 is provided outside the electrode body of the permanent magnet. The remaining configuration is common in addition to the difference in the configuration that accompanies this, and the difference will be mainly described with reference to FIG.

Metal lids 32 and 33 are welded and hermetically sealed to the insulating container 31, an electrode body 34 is fixed to the metal lid 32, and an electrode body 35 advances and retreats on the metal lid 33 via a bellows 37. Installed as possible. And
A fixed electrode plate 38 containing a magnetic material 45 and a movable electrode plate 39 are arranged opposite to each other at the tips of the two electrode bodies 34, 35 so that they can come into contact with and separate from each other. Four
5, 45 are stored and fixed.

A cylindrical shield 40 surrounding the two electrode plates 38, 39 has a magnet having a concave streak, the outer circumferences of both ends of which are reduced, and the locking claws 40a whose ends are bent outward. A section 40b is provided. This magnet mounting portion 40b
An annular permanent magnet 41 is fitted around the. A plurality of slits 40c are formed in the magnet mounting portion 40b, and when mounting the magnet material 41a,
The shield 40 is reduced in diameter so that it can be fitted. Further, it is desirable that the surface of the magnet material 41a be coated with a thin metal material in order to reduce the influence of the breaking current.

In the manufacturing process of the vacuum valve thus constructed, the magnet material 41a is used instead of the permanent magnet 41 as in the first embodiment, and the magnetizing process is performed after the magnet material 41a is made into the vacuum container in the heating furnace. As a result, the magnet material 41a becomes the permanent magnet 41.

In the second embodiment, the ring-shaped permanent magnet 41 surrounds both electrode plates 38 and 39, and a longitudinal magnetic field is applied to the entire space between both electrodes 38 and 39. The breaking capacity can be increased by further diffusing the arc generated between them to the outer peripheral region. Example 2
Then, since the magnet material 41a is attached to the shield 40 and not to the electrode bodies 34 and 35, the structure of the electrode bodies 34 and 35 can be made extremely simple. further,
In the second embodiment, since the magnet material 41a is arranged close to the electromagnetic coil 52 of the magnetizing device 50, it can be sufficiently magnetized with a small amount of power consumption. Further, in the second embodiment, since the magnetic body 45 is built in both electrode plates 38, 39, the longitudinal magnetic field by the permanent magnet 41 can be further strengthened between both electrode plates 38, 39.

As described above with reference to the first and second embodiments, in the present invention, the magnet material is previously disposed in a vacuum container and vacuum-sealed, and then the magnet material is magnetized to form a permanent magnet. However, the present invention can be widely implemented without being limited to the attachment site and attachment structure of the magnets shown in these examples.
Further, it can be carried out without necessarily requiring a magnetic body.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a first embodiment.

FIG. 2 is an enlarged sectional view of the electrode plate of the same.

FIG. 3 is a partially cutaway front view of the second embodiment.

[Explanation of symbols]

 4 ... Electrode body 5 ... Electrode body 6 ... Vacuum container 11 ... Permanent magnet 11a ... Magnet material 50 ... Magnetizing device

Claims (3)

[Claims] 1. A vacuum valve in which a permanent magnet for applying a longitudinal magnetic field is provided between a pair of electrode bodies that are disposed opposite to each other in a vacuum container and can be separated from each other, and the permanent magnet comprises: A vacuum valve, wherein a vacuum container is vacuum-sealed and then magnetized by a magnetic field applied from the outside of the vacuum container. 2. The vacuum valve according to claim 1, wherein the permanent magnet is provided in the electrode body. 3. The vacuum valve according to claim 1, wherein the permanent magnet is provided outside the electrode body.