JPH06275176A - Vacuum valve and its manufacture - Google Patents

Abstract

PURPOSE:To provide a vacuum valve having a small size as the whole form which is stably usable in a vacuum circuit breaker having a large breaking capacity. CONSTITUTION:Relatively movable electrodes 1, 3 and an electric filed shield 5 are enclosed by a glass insulating cylinder 10 formed by mutually connecting two cylinder bodies 11, 12 in their opening end parts. In each cylinder body, the connected opened end part is formed of a major diameter part, and the opposite side end part of a minor diameter part. Walls 11C, 12C are formed in such a manner that they never exceed the major diameter part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve which is a breaking portion of a vacuum circuit breaker and a method for manufacturing the same.

[0002]

2. Description of the Related Art Recently, a vacuum circuit breaker has been widely used as a circuit breaker because of its long-term stability and small size. The vacuum circuit breaker diffuses and cuts off the arc in the vacuum inside the vacuum valve, and has a high withstand voltage and small insulation with good fouling characteristics so that it can be used safely for a long time even in a bad environment. Expected to have a tube. As a means for improving the withstand voltage and the fouling property, it is an effective means to make a fold on the surface of the insulating cylinder in order to increase the creepage distance thereof. The insulating container is formed of ceramics in a shape having corrugated folds so that the creeping length is longer than that, and the intermediate shield cylinder is supported by the inner wall of the valley portion of the corrugated folds (Japanese Patent Laid-Open No. 107429).
(See Japanese Patent Publication).

Further, a cushion rubber layer containing a stretchable bag-shaped insulator is provided in the space between the insulating glass tube and the vacuum switch, and liquid rubber is pressed into the bag-shaped insulator and cured, Those having improved mechanical and electrical characteristics (see Japanese Patent Laid-Open No. 54-129369) are also known.

[0004]

Conventionally, the breaking capacity expected for a vacuum circuit breaker is about 60 kA at most,
Since it was sufficient for the electrodes and the insulating cylinder surrounding them to be of relatively small dimensions, no special consideration was given to downsizing them, and an integrally molded ceramic product was usually used as the insulating cylinder. Was also easy.

In recent years, there has been an increasing demand for a vacuum circuit breaker having a breaking capacity of more than 100 kA, and accordingly, the size of the electrode and the insulating cylinder must be increased. However, manufacturing a large insulating cylinder as an integrally molded product of ceramics requires a high level of technology, and in particular, as described above, a fold is formed on the surface of the insulating cylinder to improve withstand voltage and fouling characteristics. If you want to increase the creepage distance,
In addition to the difficulty of processing, there was the inconvenience that the outer diameter was further increased. That is, when the inner electrode has a fixed size and a fold is provided in the circumferential direction of the insulating tube, the height of the fold is added to the thickness of the insulation of the insulating tube, and the outer shape is further increased by that amount. . Further, even in the case where the bag-shaped insulator is interposed between the insulating glass tube and the vacuum switch, there is a similar inconvenience in increasing the size.

That is, it can be said that the vacuum valve used in the conventional vacuum circuit breaker has not been sufficiently considered in terms of its small size and high performance. It is an object of the present invention to provide a method for manufacturing a vacuum valve that can easily manufacture a relatively large vacuum valve that can be used in a vacuum circuit breaker having a large breaking capacity. Still another object of the present invention is to provide a vacuum valve which can be stably used in a vacuum circuit breaker having a large breaking capacity while having a small overall shape, and a method of manufacturing the vacuum valve. .

[0007]

In order to achieve this object, according to the present invention, basically, electrodes arranged coaxially opposite to each other and movable in the axial direction and a glass covering the electrodes are basically provided. Disclosed is a vacuum valve of a vacuum circuit breaker having an insulating cylinder, wherein the glass insulating cylinder is composed of two cylindrical bodies opposed to each other in the axial direction, and their open end portions are joined together.

Further, according to the present invention, basically, two cylinders made of high-melting glass which can face each other in the axial direction are prepared, the electrodes are assembled and housed in the respective cylinders, and then the electrodes are placed near the joints. This is a mode in which a melting point glass is placed and a high temperature is applied to the two cylinders under vacuum in a vacuum pressure high temperature tank to melt the low melting point glass at the bonding portion to bond the two cylinders.

If necessary, the electric field shield is held inside the glass insulating cylinder while being sandwiched by the inner wall of the glass insulating cylinder. Further, a concave groove may be formed on one of the opening ends of the two cylinders facing each other, and a convex groove facing the concave groove may be formed on the other end, and the concave groove may have a melting point higher than that of the constituent material of the glass insulating cylinder. It is a preferable embodiment to dispose a glass material having a low heat resistance and to bond the two cylindrical bodies by melting the glass material.

With the above structure, even a relatively large glass insulating cylinder can be easily manufactured. In still another aspect of the present invention, the shape of at least one (preferably both) of the above-mentioned two cylinders is such that the opening end on the side of joining is a large opening and the end on the opposite side is the joining. It should be smaller than the opening. And
Folds are formed on the outer circumference of the glass insulating cylinder, that is, on the outer periphery of each cylinder, within a range not exceeding the maximum outer diameter of the glass insulating cylinder. The direction of the folds may be the same as the axial direction, or may be the direction inclined with respect to the axis (preferably the direction perpendicular to the axis).

With the above structure, after the electrodes are assembled and housed in the respective cylinders, the one in which the electric field shield is arranged inside the cylinders may be processed in the vacuum pressure high temperature tank.

[0012]

According to the present invention, since the glass insulating cylinder is formed by joining the open ends of the cylindrical body divided into two in the axial direction of the electrode, a relatively large vacuum bulb is provided. Also, it becomes possible to easily form the glass insulating cylinder. Further, since the electrode is divided into two parts, the electrode can be inserted into the insulating cylinder from the opening side which is the joining end of the electrode when manufacturing, and the diameter is structurally larger than that of the conductor part. By mounting the electrode portion so as to be located in the vicinity of the opening that serves as the joining end of the tubular body, it is possible to form the end portion on the opposite side of the tubular body with a small diameter as a result. As a result, the total volume of the vacuum valve can be reduced by the amount based on the difference in diameter.

In the present invention, a so-called fold is further formed on the surface of the cylindrical body in parallel with or inclined with respect to the axis line including the space area formed by the difference in diameter between both ends thereof. It is possible to increase the total effective area of the folds as compared with the case where the folds are formed in the cylindrical insulating cylinder body, and the creepage distance of the insulating cylinder can be further lengthened. If the folds are formed on the glass insulation cylinder, that is, on the outer circumference of each cylinder within a range that does not exceed the maximum outside diameter of the glass insulation cylinder, the maximum outside diameter of the vacuum valve must be within the maximum outside diameter of the glass insulation cylinder. It becomes possible, and further miniaturization becomes possible.

The joining of the cylindrical bodies is carried out by filling the low-melting glass in the concave grooves formed in the tip ends of the openings facing each other and the concave grooves of the convex grooves and melting them. As a result, even though the two cylinders are joined together, there is no unnecessary charging section on the surface, and stable electrical performance can be obtained. Further, the joining of the two cylinders can be easily carried out by applying a high temperature to the two cylinders under vacuum in a conventionally known vacuum pressure high temperature tank to melt the low melting point glass filled in the groove. This can be done, and the manufacturing process can be simplified.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments of a vacuum valve and a method of manufacturing the same according to the present invention will be described below with reference to FIGS. FIG. 1 shows a cross-sectional view of an embodiment of a vacuum valve according to the present invention, in which a fixed electrode 1 and a fixed conductor 2 and a movable electrode 3 mechanically connected to the fixed electrode and a movable electrode 3 are similarly mechanically connected. And the moving conductors 4 connected to each other are arranged to face each other on the coaxial line. The fixed electrode 1 and the fixed conductor 2, and the movable electrode 3 and the movable conductor 4 are provided in an insulating cylinder 10 made of high melting point glass, which is composed of two cylinders facing each other in the same axial direction as the electrodes. The contact portion of the two electrodes is housed so as to be located in the vicinity of the joint portion of the two cylindrical bodies.

The two tubular bodies, ie, the fixed insulating tubular body 11 and the movable insulating tubular body 12, are both open end portions 11 facing each other.
B and 12B side is the large diameter portion and the opposite opening end portion 11A,
The 12A side is formed in the small diameter portion. The large-diameter-side opening end portion and the small-diameter-side opening end portion are formed by continuous wall portions, that is, large-diameter tubular portions 11E and 12E, reduced-diameter portions 11F and 12F, and small-diameter tubular portions 11G and 12G. As shown in FIG. 2, the large-diameter-side open end portions 11B and 12B are provided with a concave groove 11D on one side and a convex groove 12D on the other side to be fitted into the concave groove. As will be described later, the concave groove and the convex groove are formed. The two are integrally joined by melting the low melting glass placed between the two.

A fixed cap 7 is connected near the end of the fixed conductor 2 opposite to the connection with the fixed electrode 1, and the periphery of the fixed cap 7 is the small diameter end 11A.
In, it is connected to the fixed insulating cylinder 11. Movable conductor 4
One end of the bellows 6 is connected to the intermediate part of the bellows 6, and the movable side cap 8 is connected to the other end of the bellows 6, and the periphery of the movable side cap 8 is the small diameter side end 12A.
In, it is connected to the movable insulating cylinder 12. As a result, the inside of the glass insulating cylinder 10 made up of the two insulating cylinders 11 and 12 is placed in an environment that is shielded from the outside, and is maintained in a high vacuum state.

In the glass insulating cylinder 10, a conventionally known insulating shield 5 is arranged with an insulating distance from the fixed electrode 1 and the movable electrode 3. As shown in FIG. 1, the insulating shield 5 is a tubular body having a cross section in which both ends are curved inward, and the length of the tubular portion is the large diameter tubular portion 11 of the fixed insulating tubular body 11.
E and the large-diameter tubular portion 12E of the movable insulating tubular body 12 are approximately the same in length, and the curved portion is sandwiched between the shoulder portions of the reduced diameter portions 11F, 12F of the tubular bodies 11, 12. Is fixed in the glass insulating cylinder 10.

Further, the small-diameter cylindrical portions 11G and 12G of each cylindrical body
The folds 11C and 12C are formed in the direction perpendicular to the axis. In the one shown in FIG. 1, this fold 11C and 1
2C is formed in a direction perpendicular to the axis within a range that does not exceed the maximum outer diameter of the glass insulating cylinder 10, that is, within a range that does not exceed the outer diameters of the large-diameter cylindrical portions 11E and 12E. In the above vacuum valve, the glass insulating cylinder is divided into two parts, and each cylinder has a large diameter portion at one end and a small diameter portion at the other end.
Therefore, the electrode portion which must be relatively large in size is located in the vicinity of the end portion on the large diameter side, and the tip of the conductor connected to the electrode is extended to the outside from the end portion on the small diameter side,
Furthermore, it becomes possible to construct a fold in the space between the maximum outer diameter and the minimum outer diameter of the glass insulating cylinder, and as a result, even in the case of a vacuum circuit breaker having a large breaking capacity, the vacuum valve itself is Can be configured as a small one.

In the vacuum valve 10 having the above-mentioned structure, the operation of the vacuum valve 10 at the time of disconnection, the structure of the electrodes and the conductors mechanically connected to the electrodes, and the bellows for moving the fixed cap and the movable electrode. The configuration and the like are the same as those in the conventional vacuum valve, and thus detailed description will be omitted. FIG. 2 shows another embodiment of the vacuum valve according to the present invention. The vacuum valve according to this embodiment has the same structure as that of FIG. 1 except that the structure of the folds formed on each cylinder is different from that of FIG. That is, in this embodiment, the folds 21C and 22C are formed in the direction parallel to the axial direction of the electrodes and in the above-described reduced diameter portions 11F and 12F. It is easily understood that this one can also achieve the same effects as those of FIG.

Next, a method of manufacturing the above vacuum valve will be described. First, the two cylindrical bodies of the above-mentioned form, that is, the fixed insulating cylinder 11 and the movable insulating cylinder 12 are prepared.
A high melting point glass is used as a raw material and is manufactured by any conventionally known manufacturing method. Next, the electrodes, caps, bellows, etc. are assembled and housed inside the fixed insulating cylinder 11 and the movable insulating cylinder 12, respectively. After that, the fixed insulating cylindrical body 11 after assembly is installed by being supported by a mold in a vacuum pressure high temperature tank with the small-diameter opening end 11A as the bottom side, and the concave groove formed in the large-diameter opening end 11B. A low melting glass powder is placed in 11D. Further, the insulating shield 5 is inserted along the inner wall of the fixed insulating cylindrical body 11 so that the curved portion thereof contacts the reduced diameter portion 11F.

In this state, the movable insulating cylinder 12 after assembly, which is another cylindrical body, has the convex portion 12D formed on the large-diameter open end 12B thereof and the fixed insulating cylinder 1 is already installed.
It is arranged on the fixed insulating cylindrical body 11 so as to enter the concave groove 11D formed in the large-diameter open end portion 11B of No. 1. Then, the inside of the vacuum pressure high temperature chamber is evacuated and heated.
As a result, the low-melting-point glass located at the joint portion composed of the concave groove and the convex groove is melted and the two cylinders are integrally joined. After the joining, the vacuum pressure high temperature tank is opened and the molded vacuum valve is taken out of the tank to form the vacuum valve according to the present invention.

As another manufacturing method, the fixed insulating cylinder 11 and the movable insulating cylinder 12 in which electrodes and the like are assembled are assembled with a low melting point glass arranged at the joint, It may be inserted and fixed in the high temperature tank, and then the vacuum pressure high temperature tank may be evacuated and heated. The above description describes some of the preferred embodiments of the vacuum valve and the manufacturing method thereof according to the present invention, and there are many other variations. For example, although not particularly shown, the two cylindrical bodies forming the glass insulating cylinder may have substantially the same outer diameter, that is, a shape in which the outer diameters at both ends do not change. Even in such a case, the object of the invention that the respective glass bodies can be easily manufactured by dividing the glass insulator into two can be achieved.

Furthermore, it is not essential to form the folds formed on the surface of the glass insulator within the maximum outer diameter,
It will be readily appreciated that folds may be formed that exceed the maximum outer diameter if the environment of use allows.

[0025]

As described above, according to the present invention, since the glass insulating tube is divided into two parts, a relatively large vacuum bulb can be easily formed. Also,
By dividing into two, it is possible to form a cylindrical body with one end having a large diameter and the other end having a small diameter. As a result, the total volume of the vacuum valve can be reduced by the amount based on the difference in diameter. Furthermore, it is possible to form a so-called fold in the space area formed on the surface of the cylindrical body by the difference in the diameters of both ends thereof, and the total effective area of the fold can be increased. When the folds are formed only in the space area, the size can be further reduced.

Further, the joining of the cylindrical bodies is preferably carried out by filling the low melting point glass into the concave groove formed in the opening tips facing each other and the concave groove among the convex grooves and melting the glass. As a result, although the two cylinders are joined together, an unnecessary charging portion is not formed on the surface thereof, and stable electrical performance can be obtained. Furthermore, the joining of the two cylinders can be easily performed in a conventionally known vacuum pressure high temperature tank.

[Brief description of drawings]

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

FIG. 2 is an enlarged cross-sectional view of a connection portion.

FIG. 3 is a cross-sectional view of another embodiment of the vacuum valve of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixed electrode, 2 ... Fixed conductor, 3 ... Movable electrode, 4 ... Movable conductor, 5 ... Insulation shield, 6 ... Bellows, 7 ... Fixed side cap, 8 ... Movable side cap, 11 ... Fixed insulating cylinder, 11
A ... small diameter opening end, 11B ... large diameter opening end, 11C ...
Folds, 11D ... Grooves, 12 ... Movable insulating cylinder, 12A ... Small diameter opening end, 12B ... Large diameter opening end, 12C ... Folding, 12D ...
Convex part, 13 ... junction part,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Koguchi 1-1-1 Kokubuncho, Hitachi City, Ibaraki Prefecture Hitachi Co., Ltd. Kokubun Plant

Claims (10)

[Claims] 1. A vacuum valve of a vacuum circuit breaker, comprising: electrodes arranged coaxially to face each other and movable relative to each other in the axial direction; and a glass insulating cylinder covering the electrode, wherein the glass insulating cylinder. Is a vacuum valve characterized in that it is formed by joining two cylindrical bodies opposed to each other in the axial direction to each other at their open end portions. 2. A vacuum valve of a vacuum circuit breaker, comprising: electrodes which are coaxially opposed to each other and which are relatively movable in the axial direction; and a glass insulating cylinder which covers the electrode. Is formed by joining two cylindrical bodies opposed to each other in the axial direction to each other at their opening end portions, and an electric field shield is sandwiched by the inner wall portion of the glass insulating cylinder inside the glass insulating cylinder. A vacuum valve characterized by being held in a state. 3. A concave groove is formed on one of the opening ends of the two cylinders facing each other, and a convex groove is formed on the other end so as to face the concave groove. The vacuum valve described in 2. 4. The joining of the opening end portions is performed by melting a glass material having a melting point lower than that of the constituent material of the glass insulating tube.
Vacuum valve according to any of the above. 5. The at least one tubular body of the two tubular bodies is characterized in that an end opposite to the joined open end is formed smaller than the joined open end. The vacuum valve according to any one of claims 1 to 4. 6. The vacuum valve according to claim 1, wherein the glass insulating cylinder has a fold on its outer circumference. 7. The folds are formed toward the axial direction and / or in a direction inclined to the axial line within a range that does not exceed the maximum outer diameter of the glass insulating cylinder. 6. The vacuum valve according to 6. 8. A method of manufacturing a vacuum valve of a vacuum circuit breaker, comprising electrodes arranged coaxially opposite to each other and movable relatively in the axial direction, and a glass insulating cylinder covering the electrodes. Two cylinders made of high-melting glass that can face each other in the axial direction are prepared, and electrodes are assembled and housed inside each cylinder, and a low-melting glass is arranged near the joint,
A method for manufacturing a vacuum valve, characterized in that a high temperature is applied to the two cylinders in a vacuum pressure high temperature tank under vacuum to melt the low melting point glass in the joint portion to bond the two cylinders. 9. A method for manufacturing a vacuum valve of a vacuum circuit breaker, comprising electrodes arranged coaxially to face each other and relatively movable in the axial direction, and a glass insulating cylinder covering the electrodes, Prepare two cylinders made of high melting point glass that can face each other in the axial direction, assemble and house the electrodes inside each cylinder, place the low melting point glass in the vicinity of the joint, and place the electric field inside the cylinder. A shield is arranged, and a high temperature is applied to the two cylinders under vacuum in a vacuum pressure high temperature tank.
A method for manufacturing a vacuum valve, characterized in that the low melting point glass in the joint portion is melted to join the two cylindrical bodies. 10. A method for manufacturing a glass insulating cylinder of a vacuum valve used in a vacuum circuit breaker, characterized in that the glass insulating cylinders divided into two are butted, and the butted portions are joined and integrated by melting the low melting point glass. .