JPS60205931A - 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 the Invention] The present invention relates to a vacuum valve with an improved means for driving a moving electrode.

[Technical background of the invention and its problems]

Generally, a vacuum valve is constructed as shown in FIG. That is, end plates 2b and 3 are provided at both ends of the cylindrical electrically insulating container 1.
b are hermetically sealed to form a vacuum vessel, and a fixed electrode 2a is hermetically fixed to one end plate 2b. Further, a contact electrode 3a is airtightly attached to the other end plate 3b via a metal bellows 3 so as to be able to come into contact with and separate from the electrode 2a.

Further, an arc shield 4 is provided around the fixed electrode 2a and the detachable electrode 3a. This arc shield 4 protects the electrode 2. This prevents the inner surface of the electrically insulating container 1 from being contaminated by metal vapor generated from between a and 3a.

In order for a vacuum valve to fully demonstrate its function, the inside must be 1.
A high vacuum of 0' Torr or less is required.

A flexible metal bellows 3 is used to bring the electrode 3a into contact with and separate from the electrode 2a while maintaining such a high vacuum.
It is well known that this is essential and widely used in vacuum valves. In order to provide metal bellows used for such purposes with sufficient flexibility, it is necessary to mold the metal bellows to a thickness of about 0.1 to 0.3 mm.

However, in recent years, air pollution due to acidic gases has been increasing, and for example, when a vacuum valve is used in an electrical system in an area with particularly severe air pollution, the bellows 3 made of thin metal can become contaminated relatively easily. Corrosion occurs in the atmosphere, and grain boundary cracking and pitting corrosion occur in the metal of the bellows 3.

When such a phenomenon occurs, air leaks into the vacuum valve, the degree of vacuum required to maintain the function of the vacuum valve decreases, and the function of the vacuum valve completely stops.

In order to prevent the metal bellows 3 from being corroded by contaminated air, for example, there is a method of applying a commercially available oil-based anticorrosive agent to the parts exposed to the air. However, this does not provide stable corrosion protection semi-permanently. Furthermore, if an anti-corrosion agent is used to form an anti-corrosion film on the parts that come into contact with the atmosphere, the flexibility of the metal bellows 3 will be reduced, the elasticity of the metal bellows will be reduced, and its mechanical life will be shortened. It will be short-lived.

To achieve permanent corrosion protection, it is necessary to completely isolate the vacuum valve from contaminated air, and to meet this requirement, the vacuum valve must be housed in an airtight box. However, in this case, the vacuum valve becomes extremely expensive and is not economical.

Therefore, if it is necessary to use the vacuum valve in such a polluted atmosphere or in a similar environment, it is possible to use a bellows molded from a highly corrosion-resistant material containing a large amount of nickel, for example.

However, these materials are generally hard and therefore extremely difficult to form into bellows compared to materials such as stainless steel or phosphor bronze, and the bellows forming process requires multiple vacuum annealing. This highly corrosion-resistant material containing a large amount of nickel has the drawback that the material itself is expensive, and in addition, the bellows forming process is complicated, making it extremely expensive.

Furthermore, it is extremely difficult to achieve an airtight seal with this material by welding or silver soldering, and when bellows molded from this material are used, for example, in a vacuum valve as shown in Figure 1, special welding techniques or special welding techniques are required. Silver soldering technology is required.

[Purpose of the invention]

An object of the present invention is to provide a highly reliable vacuum valve in which the electrodes of the vacuum valve can be connected to and separated from each other without using metal bellows, in order to maintain stable corrosion resistance for a long period of time.

[Summary of the invention]

The present invention relates to a vacuum valve that is provided with a fixing device and a contact/separate electrode that connects and separates from the fixing device in a vacuum container, and is connected to one end of the vacuum container so as to communicate with the inside of the vacuum container in a vacuum state, and is connected to the inside of the vacuum container so as to communicate with the inside of the vacuum container in a vacuum state. A cylindrical holder with a bottom that holds the shaft part of the separation electrode so that it can move back and forth in the direction of contact and separation from the fixed electrode, and a space between the holder and the separation electrode that allows the movement of the separation electrode as described above. The bellows is equipped with an electromagnetic device that generates an acting force in the advancing and retracting direction between a connecting body that conductively connects in a state where the bellows The movable contact and separation electrodes can be moved forward and backward without using the movable electrode.

[Summary of the invention]

The present invention comprises a plurality of magnetic bodies on the shaft portion of the contacting and separating electrodes, and the shaft of the contacting and separating electrodes is moved magnetically by a plurality of electromagnetic coils provided outside the vacuum valve. It is a vacuum valve that provides contact and separation of the contact and separation electrodes.

[Embodiments of the invention]

The present invention will be described in detail below with reference to an embodiment shown in the drawings. In FIG. 2, the electric P, the edge container 1 have an end plate 2b,
3b, both ends are hermetically sealed to form a vacuum container. A pair of electrodes 2a is provided inside the vacuum container.

3a, and the electrode 2a is a fixed type polarization hermetically sealed to the end plate 2b. The electrode 3a facing this is a movable electrode. Reference numeral 4 denotes an arc shield placed so as to surround the space between the electrodes. 6 is a cylindrical holding body with a bottom;
It is connected to the center of the end plate 3b constituting one end of the vacuum container so as to communicate with the inside of the vacuum container in a vacuum state. Further, the shaft portion of the contacting/separating electrode 3a is held within this so as to be movable in the direction of contacting and separating from the fixed electrode 2a. 3e is a shaft guide for holding the shaft portion so as to be movable back and forth.

An electromagnetic column 3C made of a magnetic material is integrally provided on the shaft portion of the contacting/separating electrode 3a. This electromagnetic column 3C is shown in Fig. 3 (
As shown in a) and (b), it is divided into two parts on the circumferential surface of the shaft part, and '!' on the electromagnetic column 3C itself. ! This prevents flow loops from occurring. 3d is a connecting body, and a holding body 6
A conductive connection is made between the contact electrode 3a side and the contact electrode 3a side in a state that allows the forward and backward movement of the contact #II polarization 3a. As an example of this connecting body 3d, a current-carrying band made of flexible metal is shown in the figure, but it may be of a sliding contact type.

Reference numeral 7 denotes an electromagnetic device, which is composed of two electromagnetic coils 7a and 7b, and is installed on the outer periphery of the holder 6 via an electrically insulating cylinder 8. Then, with the excitation of any one of the contact and separation electrodes 3a,
The contact electrode 3 is placed between the electromagnetic column 3C fixed to the side.
An acting force is generated to bring a into contact with or separate from the fixed electrode 2a.

In the above configuration, when the vacuum valve is operated to close, one of the electromagnetic coils 7a is energized to excite it. This generates electromagnetic force, which acts on the electromagnetic column 3C provided on the shaft portion of the contact/separation electrode 3a, and moves the contact/separation electrode 3a upward in the figure, bringing it into contact with the fixed electrode 2a. As a result, the vacuum valve is turned on and current can be passed between the electrodes 2a and 3a.

Next, when cutting off the current, the current is turned off to one of the electromagnetic coils 7a, and immediately the other electromagnetic coil 7b is energized to excite it. By performing this excitation, an electromagnetic force is generated in the electromagnetic coil 7bK, which acts on the electromagnetic column 3C and moves the contact/separation electrode 3a downward in the figure. For this reason, the detachable electrode 3a separates from the fixed electrode 2a,
The current flowing between these two electrodes is cut off. Furthermore, the switching of energization to the electromagnetic coils 7a and 7b is performed via a changeover switch (not shown) or the like.

Here, the contact/separate electrode 3a, the holder 6 of the electrode shaft portion, and the shaft guide 3e are all at the same potential. Moreover, the electromagnetic coil 7a,
7b and the holder 6 are electrically insulated by an electrically insulating tube 8. Therefore, by alternately energizing the electromagnetic coil 7a or 7b, the electromagnetic force generated therein can be applied to the contact and separation electrodes 3a. The shaft portion acts with the fc electromagnetic column 3c to reciprocate the contact and separation electrodes 3a. As a result, electrodes 2a, 3a
To provide a vacuum valve as a safe and highly reliable current switching path by causing connection and separation between the valves.

Note that the electromagnetic device 7 includes two electromagnetic coils 7a and 7b.
However, the present invention is not limited to this, and the contact and separation electrodes may be driven by using, for example, one electromagnetic coil and moving it up and down.

〔Effect of the invention〕

As explained above, according to the present invention, the contact and separation electrodes of the vacuum valve are magnetically driven into contact and separation from the outside of the vacuum vessel, so unlike conventional vacuum valves, metal bellows are not damaged due to air pollution, etc. Vacuum breakdown due to corrosion and the resulting deterioration of vacuum valve functionality can be prevented. Therefore, a highly reliable vacuum valve that is stable for a long period of time can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional vacuum valve, Fig. 2 is a sectional view showing an embodiment of the vacuum valve according to the present invention, and Fig. 3 (
aJ, (b) is a plan sectional view and a front view showing an example of the structure of the electromagnetic column shown in FIG. 2; l・1.・1 Electrical insulating container 2a...Fixed electrode 2b・
...End plate 3a°° contact and separation electrode 3b...End plate 3C3''1 Magnetic body 3d...Connection body 3e...Axle guide 7...Electromagnetic device (7317) Agent Patent attorney Nori Chika Yu (1 person) Figure 1 Figure 2

Claims (1)

[Claims] A vacuum valve is provided with a fixed electrode and a separating electrode that comes into contact with and separates from the fixed electrode in a vacuum container, and the shaft of the separating electrode is connected to one end of the vacuum container so as to communicate with the inside of the vacuum container in a vacuum state. A cylindrical holder with a bottom is held so that it can move forward and backward in the direction of contact with and away from a fixed fixed electrode, and conduction is established between the holder and the contact electrode in a state that allows the contact electrode to move back and forth. It is characterized by comprising a magnetization device that generates an acting force in the advance/retreat direction between the connecting body to be connected and a magnetic body attached outside the holding body and fixed to the contact/separation electrode side. vacuum valve.