JPH06150782A - Vacuum valve - Google Patents

Abstract

PURPOSE:To provide a vacuum valve which involves a low surge and is equipped with a large current breaking characteristic. CONSTITUTION:Contacting pieces 2a, 2b are made of AgWC alloy while arc electrodes 12a, 12b are made of CuMoTa alloy or CuMoNb alloy. A vertical magnetic field electrode is furnished whereby a magnetic field over a peak value of the 50-Gauss rated breaking current is impressed on an arc column in the direction of the current feed axis by coil electrodes 11a, 11b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve capable of blocking a large current, and more particularly to a vacuum valve having a longitudinal magnetic field electrode having a low surge performance and a large current blocking capability.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing an example of a conventional vacuum valve. For example, Japanese Patent Publication No. 63-59215 discloses a vertical magnetic field electrode for a vacuum valve. In the figure, 3 is a vacuum valve. A pair of electrodes 6a and 6b which can be freely contacted and separated is arranged in a vacuum container by closing both ends of an insulating container 4 made of ceramic or the like with end plates 5a and 5b. One electrode (fixed electrode) 6a has a fixed electrode rod 7a. Is connected, and the movable electrode rod 7b is connected to the other electrode (movable electrode) 6b. The fixed electrode rod 7a penetrates the end plate 5a and projects to the outside, and the movable electrode rod 7b is fixed to the bellows 8 attached to the end plate 5b and penetrates the end plate 5b to project to the outside. The inside of the vacuum container maintains a vacuum state, and the electrodes 6a and 6b arranged so as to face each other have a shape that can be freely contacted and separated. The arc shield 9 prevents the metal vapor generated from the electrodes 6a and 6b from opening and closing the current from polluting the inner wall of the insulating container 4. The electrodes 6a and 6b are composed of contacts 10a and 10b whose contact portions are made of AgWC alloy and coil electrodes 11a and 11b provided behind them.

Next, the operation will be described. In the vacuum valve of FIG. 5, when the electrodes 6a and 6b are opened, an arc is generated between the contacts 10a and 10b, and the contact 10
The current flowing through a and 10b is the coil electrode 11 behind it.
A magnetic field is generated in the direction of the current-carrying axis with respect to the arc column by the currents flowing in a and 11b. Therefore, when the current is cut off, a magnetic field is applied in parallel with the arc, so that the arc voltage can be suppressed low. Moreover, since the arc spreads over the entire contact, contact 1
Local overheating to 0a and 10b can be prevented, and the current density can be reduced, so that a large current can be cut off. When low surge performance is required, the material of the contacts 10a and 10b of the electrodes is AgWC alloy or C suitable for low surge.
The uCrBi alloy was used as the contact material.

In the vacuum valve described in Japanese Examined Patent Publication No. 63-59215, A is used as the material for the contacts 10a and 10b.
It is described that when a magnetic field having a peak value (unit KA) of 50 Gauss / rated breaking current is generated using a gWC alloy, the breaking performance is improved. However, there is a limit to the improvement of breaking performance, withstand voltage performance, and welding performance with one type of contact material. Therefore, as shown in FIG. 6, an electrode structure is proposed in Japanese Patent Application Laid-Open No. 3-98222, etc., in which the contact 20 and the arc electrode 21 are divided into two regions to improve the characteristics.

[0005]

By the way, Japanese Patent Publication No. 63-
In the vacuum valve described in Japanese Patent No. 59215, one kind of contact material is used, and there is a limit in improving the breaking performance, withstand voltage performance, and welding performance. Also, in this publication,
It is described that the interruption phenomenon is different between the AgWC system contact and the Cu system contact (for example, CuBi system). This indicates that the appropriate magnetic field applied differs depending on the material of the contact. To improve this conventional vacuum valve,
When the electrode structure is a two-region structure as in the latter example,
Since the strength of the magnetic field generated by the coil electrode is a constant value, even if the magnetic field strength is adjusted to an appropriate value for one contact material, the magnetic field strength may not be appropriate for the other contact material. However, even if the structure of the electrode is simply a two-region structure, there is a drawback that the characteristics of the electrode cannot be sufficiently improved.

The present invention has been made in order to solve the above-mentioned problems, and an electrode having a low surge and a large current interruption characteristic is formed by a two-region electrode structure in which a plurality of contact materials with an appropriate magnetic field are combined. An object is to provide a vacuum valve provided with the vacuum valve.

[0007]

A vacuum valve according to the present invention is provided with a fixed electrode and a movable electrode, which are opposed to each other in a vacuum container so as to freely come into contact with and separate from each other, and a material of a contact of the electrode is an AgWC alloy. The arc electrode is provided with an electrode made of a CuMoTa-based alloy or a CuMoNb-based alloy.
Further, the vacuum valve of the present invention is provided with a fixed electrode and a movable electrode, which are arranged to face each other so as to be able to come into contact with and separate from each other, in a vacuum container, and AgWC alloy is used as a material of a contact of these electrodes, and a material of an arc electrode is used. A CuMoTa-based alloy or CuMoNb-based alloy was used for the vertical magnetic field electrode for applying a magnetic field of 50 Gauss / wavelength of peak breaking current (unit KA) or more to the arc column by the coil electrode in the energizing axis direction. It is a thing.

[0008]

[Operation] By using the vacuum valve as described above,
A two-region electrode structure made of a material suitable for large current interruption and a material having low surge performance makes it a vacuum valve with low surge and excellent interruption performance. Furthermore, by applying a magnetic field of 50 Gauss / crest value of the rated breaking current (unit KA) or more to the arc column by the coil electrode, the low surge characteristic is maintained and the maximum current breaking performance is achieved. It is a vacuum valve.

[0009]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a pair of electrodes 1a and 1b which can be freely contacted and separated is arranged in a vacuum container in which both ends of an insulating container 4 made of ceramic or the like are closed by end plates 5a and 5b, and one electrode (fixed electrode) 1a is provided. Is connected to the fixed electrode rod 7a, and the other electrode (movable electrode) 1b is connected to the movable electrode rod 7b. The fixed electrode rod 7a keeps the airtightness and the end plate 5a.
And the movable electrode rod 7b is protruded to the outside through the end plate 5b.
It is fixed to the bellows 8 attached to and is projected from the end plate 5b. The interior of the vacuum container has a structure in which the electrodes 1a and 1b can freely come into contact with and separate from each other while maintaining a vacuum. In the vacuum container, an arc shield 9 is arranged so as to surround the electrodes 1a and 1b to prevent the metal vapor generated from the electrodes 1a and 1b when the current is opened and closed from polluting the inner wall of the insulating container 4. There is. The electrodes 1a, 1b are composed of contacts 2a, 2b made of an AgWC alloy, arc electrodes 12a, 12b provided one step lower than the contacts 2a, 2b, and coil electrodes 11a, 11b provided behind them. There is. When the electrodes 1a and 1b are in the closed state, the contacts 2a and 2b are in contact with each other, but the arc electrodes 12a and 12b are not in contact with each other. Arc electrodes 12a, 12b
As the material of CuMoTa-based alloy or CuMoNb-based alloy is used.

FIG. 2 shows the limit breaking current of each contact material. As is clear from the figure, the CuMoTa-based alloy, the CuMoNb-based alloy, and the CuCr-based alloy have better breaking performance than the AgWC-based alloy. Among various contact materials, CuMoTa-based alloys and CuMoNb-based alloys,
Since the CuCr alloy is a non-low surge contact material, it cannot be used for a contact as a low surge vacuum valve. Therefore, it has been considered that the two-region electrode structure has a low surge performance and has a large current interruption capability.

FIG. 3 shows the magnetic field strength applied to a single electrode contact and the breaking performance. Ag as contact material
WC-based alloys, CuMoTa-based alloys, CuMoNb-based alloys, and CuCr-based alloys were used, and the magnetic field in the axial direction was applied to the contacts made of these materials, and their breaking performance was examined. As a result, with respect to the AgWC-based alloy, CuMoTa-based alloy, and CuMoNb-based alloy, when the magnetic field having a crest value (unit KA) of 30 Gauss / rated breaking current in the direction of the energizing axis with respect to the arc column, the breaking performance is a little. It only improves. However, it was found that when the magnetic field strength was set to 50 Gauss / peak value of the rated breaking current (unit KA), the breaking performance was dramatically improved in all cases. Also, AgWC alloy and C
With the uMoTa-based alloy or the CuMoNb-based alloy, the breaking performance was good even in a magnetic field exceeding 50 Gauss / rated breaking current (unit KA).

On the other hand, in the CuCr alloy contact, the breaking performance peaks at a peak value of 30 Gauss / rated breaking current (unit KA), and conversely at a peak value of 50 Gauss / rated breaking current (unit KA). It became clear that the magnetic field strength did not match that of the AgWC alloy contacts. On the other hand, AgWC alloy and CuMo
Although the Ta-based alloy and the CuMoNb-based alloy differ in the range of the limit breaking current, the rate of change is similar, and it was found that they can be used in the optimum magnetic fields.

From the above results, the materials of the contacts 2a, 2b are AgWC type alloys, the materials of the arc electrodes 12a, 12b are CuMoTa or CuMoNb type alloys, and the contacts 2a, 2b and the arc electrodes 12a, 12b are respectively combined. The electrodes 1a and 1 which can be used as two-region electrodes and can cut off a large current with a low surge by applying an optimum axial magnetic field (longitudinal magnetic field) of the same strength by the coil electrodes 11a and 11b.
It can be b.

That is, the contacts 2a and 2b and the arc electrode 12
a and 12b act as an arc diffusion part. When the small current is cut off, the diameter of the arc is small, so that it stays on the contact surface of the AgWC alloy contact and is cut off by the AgWC alloy contact, so that low surge performance can be maintained. When a large current is cut off, the arc is diffused and cut off to the arc electrodes 12a and 12b made of CuMoTa-based alloy or CuMoNb-based alloy. Therefore, AgWC is applied to the contacts 2a and 2b.
Even if a system alloy is used, the breaking performance at the time of breaking a large current maintains the breaking performance equivalent to that tested by a single contact material.

Example 2. In the above embodiment, one contactor 2a, 2b is provided at the center of each electrode, but at the position where the contactor is installed, the coil electrodes 11a, 11b generate an axial magnetic field (longitudinal magnetic field). It may be installed anywhere in the area, and is not limited to the embodiment of FIG.
In the embodiment shown in FIG. 4, a pair of electrodes 14a and 14b which can be freely contacted and separated from each other is provided in the insulating container 4, and the electrodes 14a and 14b are
Arc electrodes 12a and 12b and arc electrodes 12a and 12
a plurality of contacts 13a provided near the outer periphery of b
13b and coil electrodes 12a and 12b provided behind the arc electrodes 12a and 12b, respectively. The material of the arc electrodes 12a and 12b is CuMo.
Ta or CuMoNb type alloy, and contacts 13a, 1
The material of 3b is an AgWC alloy. Of course, the structure of the contact may be ring-shaped.

[0016]

As described above, according to the present invention, by using AgWC type alloy as the material of the contact and CuMoTa type alloy or CuMoNb type alloy as the material of the arc electrode, a large current interruption can be achieved. A vacuum valve suitable for interrupting a small current can be provided. Further, the coil electrode is used as a longitudinal magnetic field electrode that applies a magnetic field of 50 Gauss / wavelength of the rated breaking current (unit KA) or more to the arc column in the energizing axis direction, thereby improving breaking performance with low surge. In addition to being able to do so, it also has the effect of making the electrodes smaller.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a vacuum valve of the present invention.

FIG. 2 is a diagram showing the breaking performance of various contact materials.

FIG. 3 is a diagram showing a relationship between an axial magnetic field of various contact materials and a breaking current.

FIG. 4 is a sectional view showing another embodiment of the vacuum valve of the present invention.

FIG. 5 is a diagram showing an example of a conventional vacuum valve.

FIG. 6 is a cross-sectional view showing another electrode of a conventional vacuum valve.

[Explanation of symbols]

 1a, 1b 14a, 14b electrode 2a, 2b, 13a, 13b contactor 3 vacuum valve 4 insulating container 5a, 5b end plate 7a fixed electrode rod 7b movable electrode rod 8 bellows 9 arc shield 11a, 11b coil electrode 12a, 12b arc electrode

Claims (2)

[Claims] 1. In a vacuum valve having a fixed electrode and a movable electrode, which are arranged to face each other so as to come into contact with and separate from each other in a vacuum container, a material of a contact of the electrode is an AgWC alloy, and a material of an arc electrode is CuMoTa. A vacuum valve comprising an electrode made of a Cu-based alloy or a CuMoNb-based alloy. 2. In a vacuum valve having a fixed electrode and a movable electrode, which are arranged to face each other so as to come into contact with and separate from each other in a vacuum container, a material of a contact of the electrode is an AgWC alloy, and a material of an arc electrode is CuMoTa. A vacuum valve, characterized in that it is made of a Cu-based alloy or a CuMoNb-based alloy, and is a longitudinal magnetic field electrode for applying a magnetic field of 50 Gauss / higher than the peak value of the rated breaking current to the arc column in the energizing axis direction by the coil electrode.