JPH08222089A - Vacuum bulb - Google Patents

Abstract

PURPOSE: To enhance the carrying-current without enlarging the outer form by forming at least one of a fixed electrode and a movable electrode by impregnating a highly conductive part consisting of a highly conductive material with a material lower in conductivity than it. CONSTITUTION: At least one of a fixed electrode and a movable electrode is formed by impregnating a highly conductive coil electrode with a material slightly lower in conductivity than it. Namely, an impregnated part 1b impregnated with the material slightly lower in conductivity than a highly conductive part 1a is formed between a current-carrying shaft 4 and a contact 2. The part 1a is, for example, formed of copper, and an alloy lower in conductivity than copper such as silver-copper alloy is impregnated in the space part, whereby an electrode 1 is formed. At current-carrying, a large current can be carried since the current is carried to the whole electrode, while the large current can be interrupted with a small electrode at interruption since the interrupting performance is enhanced by forming a longitudinal magnetic field or vertical magnetic field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve having an improved electrode structure and material.

[0002]

2. Description of the Related Art The structure of a vacuum valve used in a conventional vacuum circuit breaker is shown in FIG. In FIG. 7, the vacuum valve 10
Both ends of the insulating cylinder 11 are fixed flange 12 and movable flange
A fixed electrode 14 is placed inside the vacuum container sealed with 13.
And the movable electrode 15 are arranged so that they can come into contact with and separate from each other.

Of these, the fixed electrode 14 is the fixed flange 12
One end is fixed to the tip of a fixed shaft 16 that penetrates in an airtight manner by brazing, and a contact 21 is provided on the other surface, and the outside of the vacuum container is connected through the upper end of the fixed shaft 16. On the other hand, the movable electrode 15 is fixed by brazing to the tip of a movable shaft 17 that penetrates airtightly through a bellows cover 19 having an inverted U-shaped cross section, and is connected to the outside of the vacuum container via the lower end of the movable shaft 17. Connected.

The movable shaft 17 has a bellows 18 brazed between the movable flange 13 and a bellows cover 19, and a guide 20 having a convex cross-section inserted at the center of the movable flange 13 to move the movable flange 13. It is supported by and is driven by an operation mechanism portion (not shown) connected to the lower end of the movable shaft 17 while maintaining the vacuum in the vacuum container, so that the electrodes can be brought into and out of contact with each other. I have to.

By the way, as is well known, the vacuum valve is
Since the excellent dielectric strength of vacuum is used, the gap between the electrodes can be made smaller and the outer diameter can be made smaller than that of a gas circuit breaker that uses an insulating medium such as sulfur hexafluoride gas. it can. Also, the breaking capacity can be increased by improving the structure of the electrode.

As one means for improving the breaking performance of the vacuum valve, there is a method of suppressing local heating of the electrodes due to an arc generated between the electrodes. That is, by suppressing the generation of abnormal charged particles due to local heating, the generation of arcs is suppressed and the breaking performance is improved. As an electrode structure for this purpose, there are a method of applying a magnetic field parallel to the arc generated between the electrodes and a method of applying a magnetic field in a direction orthogonal to the arc.

Among them, an electrode adopting a method of applying a magnetic field parallel to an arc has a so-called longitudinal magnetic field electrode structure. In this method, the arc generated between the electrodes is dispersed over the entire electrode by the effect of the magnetic field to improve the breaking performance. On the other hand, there is a so-called spiral electrode as an electrode adopting a method of applying a magnetic field orthogonal to an arc. This method is a method in which an arc concentrated on the electrode surface when a large current is cut off is rotated on the electrode surface to improve the breaking performance. In other words, by moving the concentrated arc,
This is a method of improving the breaking performance by preventing partial melting of the contacts due to local heating of the electrodes. Since all of these electrodes control the arc by a magnetic field, the electrodes were provided with a groove for rotating and flowing an electric current.

[0008]

However, in such a conventional vacuum valve, the electrodes are complicated due to arc control, and the current-carrying area is reduced relative to the cross-sectional area, while the current-carrying current is increased. Had to further increase the cross-sectional area in order to suppress heat generation during energization. Therefore, an object of the present invention is to provide a vacuum valve capable of increasing the energizing current without increasing the outer shape (cross-sectional area).

[0009]

SUMMARY OF THE INVENTION The present invention relates to a fixed electrode and a movable electrode of a vacuum valve in which a fixed electrode and a movable electrode, which are connected to the outside via a current-carrying shaft, are housed in a vacuum container so that they can come into contact with and separate from each other. It is characterized in that at least one of them is formed by impregnating a coil electrode having high conductivity with a material slightly lower than this. The electrodes are formed by a vertical magnetic field electrode, a spiral having a groove in a disk, a contact, a coil wire, or the like, and impregnated with copper cobalt or the like.

[0010]

In the present invention, when the electrodes are in contact with each other and a current is flowing (current is flowing), a current flows through the entire electrode although there is a difference in conductivity, and the temperature rise of the electrode is suppressed. In addition, when the current is cut off (the electrodes are separated), most of the cutoff current flows in the high-conductivity area where the current is narrowed and the conductivity is high. A magnetic field is applied in parallel, and when a spiral electrode is used, a magnetic field is applied in an orthogonal direction to the arc flowing between the electrodes. Furthermore, when a coil wire is used, the strength of the inter-electrode magnetic field at the time of interruption can be easily changed by changing the number of turns.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the vacuum valve of the present invention will be described below with reference to the drawings. The structure of the entire vacuum valve is
Since it is the same as FIG. 7, the structure of the electrode will be described in detail with reference to FIGS. 1 to 6. Further, since the electrodes have the same structure on both the movable side and the fixed side, only one of them will be described.

FIGS. 1 and 2 show an example in which a longitudinal magnetic field electrode for applying a magnetic field parallel to an arc generated between the electrodes when the current is cut off is used in the highly conductive portion. Here, FIG. 2 shows the high-conductivity portion 1a before impregnation, the contactor 2, the reinforcing shaft 3, and the current-carrying shaft 4 attached thereto. FIG. 1 has an impregnated portion 1b in which the portion between the current-carrying shaft 4 and the contactor 2 is impregnated with a material having a slightly lower conductivity than the high conductive portion 1a.

For example, the highly conductive portion is formed of copper, and the electrode is formed by impregnating the space portion with an alloy having a lower conductivity than copper, such as a silver-copper alloy. Further, after forming a coil electrode or a spiral electrode, metal powder such as chromium is filled and then sintering is performed to form an electrode. Alternatively, copper cobalt (CuCo) may be impregnated.

In the vacuum valve having such a structure, when the electrodes are in contact with each other and a current flows, there is a partial (difference) difference in conductivity, but a current flows through the entire electrode and the temperature of the electrode changes. The rise is suppressed.

When the current is cut off, the current is narrowed, and most of the cutoff current flows through the coil electrodes having high conductivity (good), and a magnetic field is applied in parallel to the arc generated between the electrodes, so that the arc is directed to the electrode surface. Evenly.

FIGS. 3 and 4 show a second embodiment, in which a spiral coil wire 1c is used instead of the longitudinal magnetic field electrodes shown in FIGS.
Is used for the high conductivity part. The vacuum valve with electrodes constructed in this way has the same effects as the first embodiment, and the strength of the inter-electrode magnetic field at the time of interruption can be easily changed by changing the number of turns of the coil wire. The arc equalization can also be changed.

FIG. 5 shows an embodiment in which a spiral electrode for applying a magnetic field orthogonal to the arc generated between the electrodes when the current is cut off is used in the highly conductive portion. The contact 2, the spiral electrode 1c,
The current-carrying shaft 4 and a portion between the current-carrying shaft 4 and the contact 2 are made of an impregnated portion 1b in which the spiral electrode 1d is impregnated with a material having a slightly lower conductivity. Further, FIG. 6 shows an example in which a contact electrode is used for the high conductivity portion, and the electrode 1 is composed of the contact electrode 1e and the impregnated portion 1b.

When these spiral electrodes and control electrodes are used, when the electrodes are in contact with each other and a current is flowing, there is a partial difference in conductivity, but a current flows through the entire electrode, and the temperature of the electrode changes. The rise is suppressed. Further, when the current is cut off, most of the cutoff current flows in a portion where the current is narrowed and the conductivity is high, a magnetic field is generated in a direction orthogonal to the arc generated between the electrodes, and the arc is moved on the electrode surface.

[0019]

According to the present invention, since a current flows through the entire electrode during energization, a large current can be energized, and during interruption,
Since the breaking performance is improved by creating a vertical magnetic field or a vertical magnetic field, it is possible to cut a large current with a small electrode.

[Brief description of drawings]

FIG. 1A is a plan view and FIG. 1B is a front view of an embodiment of the present invention when a vertical magnetic field electrode is used.

FIG. 2 is an assembly view of an embodiment of the present invention in which a vertical magnetic field electrode is used.

3A is a plan view and FIG. 3B is a front view of an embodiment of the present invention using a coil wire.

FIG. 4 is a perspective view of an embodiment of the present invention using a coil wire.

5 (a) is a plan view and FIG. 5 (b) is a front view of an embodiment of the present invention using a spiral electrode.

FIG. 6 is a perspective view of an embodiment of the present invention using a contact electrode.

FIG. 7 is a vertical cross-sectional view showing the configuration of a general vacuum valve.

[Explanation of symbols]

1 ... Electrode, 1a ... Longitudinal magnetic field electrode (highly conductive portion),
1b ... Impregnation part, 1c ... Coil wire electrode, 1d ... Spiral electrode, 1e ... Contact electrode, 2 ... Contactor, 3 ... Reinforcing shaft, 4 ... Energizing shaft

Claims (5)

[Claims] 1. A vacuum valve in which a fixed electrode and a movable electrode, which are connected to the outside through an energizing shaft, are housed in a vacuum container so that they can be contacted and separated, at least one of the fixed electrode and the movable electrode is A vacuum valve, which is formed by impregnating a highly conductive portion made of a highly conductive material with a material having a lower electrical conductivity. 2. The vacuum valve according to claim 1, wherein the highly conductive portion is formed by a vertical magnetic field electrode. 3. The vacuum valve according to claim 1, wherein the highly conductive portion is formed by forming a groove in a disk. 4. The vacuum valve according to claim 1, wherein the highly conductive portion is formed by a coil wire. 5. The high conductivity portion is copper cobalt (CuCo).
The vacuum valve according to any one of claims 1 to 4, wherein the vacuum valve is impregnated with.