JPH06208820A - Gas insulated vacuum circuit breaker - Google Patents

Abstract

PURPOSE:To provide a gas insulated vacuum circuit breaker, in which high pressurization is enabled by restricting the difference in the pressures between the inside and outside of the surface of a bellows in a simple structure. CONSTITUTION:An end of an airtight container 21 is connected airtight-proof to a mounting base 18 mounted on an end plate 12b in the movable side of a vacuum valve through a sealing material 22a, and a mechanism part, for example, a conducting rod 16b in the movable side or a rotation shaft 41 is slidably guided out of the airtight container 21 while the airtightness is maintained, and an airtight chamber 2 is formed on a circumferential surface side of a bellows 17. The pressure in the airtight chamber 2 is an intermediate pressure between the pressure in a vacuum container 1 and the pressure of an insulating gas in a closed container, in which the vacuum valve is provided, and the difference in the pressure between the inside and outside circumferential sides of the bellows 17 is thus reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-insulated vacuum circuit breaker constructed by housing a vacuum valve in an airtight container filled with an insulating gas.

[0002]

2. Description of the Related Art Generally, there is known a gas-insulated vacuum circuit breaker in which a vacuum valve is housed in a closed container filled with an insulating gas of about several atmospheres to achieve a high voltage. However, when the vacuum valve is directly installed in the insulating gas, the bellows that holds the vacuum state in the vacuum valve and allows the opening / closing operation of the movable electrode has a vacuum state on the side of the vacuum valve. Insulating gas pressure will be applied to the other side,
This pressure difference reduces the mechanical life of the bellows. Various proposals have been made to prevent the pressure of the insulating gas from being applied to the bellows in order to prevent the shortening of the life. This will be described with reference to FIGS. 11 and 12.

FIG. 11 is a sectional view showing a conventional vacuum valve of this type disclosed in Japanese Utility Model Laid-Open No. 54-137863. Both ends of the insulating cylinder 11 are airtightly sealed by a fixed side end plate 12a and a movable side end plate 12b to form a vacuum container.
Fixed side conductive rod 1 connected to fixed side electrode 15a on 2a
6a is fixed, and the movable side end plate 12b is provided with a bevel 17 having one end airtightly connected, and the other end of the bevel 17 is airtightly connected to the movable side conductive rod 16b connected to the movable side electrode 15b. is doing. When the movable electrode 15b is opened and closed via the movable conductive rod 16b by an operation device (not shown), the bellows 17 expands and contracts to maintain the vacuum state in the vacuum container. When such a vacuum valve is placed in the insulating gas, vacuum acts on the outer peripheral surface of the bellows 17, whereas high-pressure insulating gas acts on the inner peripheral surface thereof. Therefore, the movable end plate 12b side of the insulating cylinder 11 is covered with one end of a bellows-shaped seal 21b made of conductive rubber or semi-conductive rubber, and the bellows-shaped seal 21b is formed.
The movable side conductive rod 16b is covered with the other end of the bellows 1.
The inner peripheral surface side of 7 is separated from the insulating gas. 2
1a is a seal made of a similar material that covers the fixed-side end 12a side.

FIG. 12 shows a cross-sectional view of a main part of a conventional gas-insulated vacuum circuit breaker introduced in Japanese Patent Laid-Open No. 53-80573. In a porcelain tube 5 filled with an insulating gas, a vacuum container constituted by hermetically sealing the end of the insulating cylinder 11 with a movable side end plate 12b and a bellows 17 is arranged, and one end 101 is attached to the movable side end plate 12b. A cylindrical projecting body 102 surrounding the movable conductive rod 16b by welding is provided, and a free end side of the cylindrical projecting body 102 forms a sliding portion between the free end side and the end fitting 103 of the porcelain bushing. A seal material 22 is attached to the sliding portion. A current collector 104 that electrically collects electricity is provided between the end fitting 103 of the porcelain insulator 5 and the movable conductive rod 16b. Therefore, the insulating gas in the porcelain tube 5 is shielded from the cylindrical projection 102.
The inner surface side of the bellows 17 is divided into the atmospheric pressure through the sliding portion of the current collector 104 so that the gas pressure of the insulating gas does not act on the inner surface side of the bellows 17. .

In another conventional gas-insulated vacuum circuit breaker, as shown in Japanese Patent Application Laid-Open No. 57-55022, an airtight container filled with an insulating gas is airtightly divided by an insulating spacer. The vacuum valve is arranged in the section where the gas pressure is lower than that in the other sections, thereby reducing the pressure difference applied to the inside and outside of the bellows.

[0006]

However, each of the conventional gas-insulated vacuum circuit breakers described above has a complicated structure or is not suitable for an actual gas-insulated vacuum circuit breaker.
For example, according to the conventional gas-insulated vacuum circuit breaker shown in FIG. 11 described above, since both ends of the bellows-shaped seal 21b are fixed to the insulating cylinder 11 and the movable side conductive rod 16b, respectively.
The bellows-shaped seal 21b made of conductive rubber or semi-conductive rubber repeatedly expands and contracts each time it is opened and closed, and its durability becomes a problem. The gas-insulated vacuum circuit breaker shown in FIG.
Although the pressure difference between the inner and outer surfaces of the bellows 17 can be reduced by opening the inner surface of the bellows 17 to the atmosphere, in a general gas-insulated vacuum circuit breaker, the movable-side conductive rod 16b and the current collector that constitute the main circuit. Although 104 is placed in an insulating gas to increase its withstand voltage, such a structure cannot be adopted. Further, in the one disclosed in Japanese Patent Laid-Open No. 57-55022, the inside of the closed container filled with the insulating gas must be divided into two parts in terms of gas, which complicates the structure and corresponds to the vacuum valve. Since the gas pressure in the selected section is lowered, the increase in voltage is hindered.

It is an object of the present invention to provide a gas-insulated vacuum circuit breaker capable of increasing the pressure by suppressing the pressure difference between the inner and outer surfaces of the bellows with a simple structure.

[0008]

In order to achieve the above object, the present invention comprises a vacuum valve arranged in a closed container filled with an insulating gas, the vacuum valve comprising a pair of separable electrodes. A gas-insulated vacuum circuit breaker equipped with an operating device connected to the movable-side electrode, and a bellows that holds the vacuum state in the vacuum valve to allow the operation of the movable-side electrode. An airtight container that is airtightly connected is provided to form an airtight chamber that communicates with one peripheral surface side of the bellows, and a mechanism section that connects the movable side electrode and the operating device is airtight from the airtight container. It is slidably led out while being held, and the airtight chamber has a pressure intermediate between the inside of the vacuum valve and the insulating gas.

[0009]

The gas-insulated vacuum circuit breaker according to the present invention forms an airtight chamber communicating with one peripheral surface of the bellows as described above, and this airtight chamber is provided with a pressure between the vacuum valve and the insulating gas. As a result, the pressure difference acting on the inner and outer peripheral surfaces of the bellows can be made smaller than in the conventional case, so that even if the pressure of the surrounding insulating gas is increased to increase the voltage, the bellows It does not shorten the life.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional view showing a vacuum valve which is a main part of a gas-insulated vacuum circuit breaker according to an embodiment of the present invention, and is wholly housed in an airtight container filled with an insulating gas (not shown). Has been done.

Sealing rings 13a and 13b are respectively provided at opposing portions of the pair of insulating cylinders 11a and 11b.
The metal rings 14 hermetically connect the rulings 13a and 13b. The fixed side end plate 1 is provided at the left end of the insulating cylinder 11a.
2a, and the fixed side electrode 15a is attached to the fixed side conductive rod 16a fixed to the fixed side end plate 12a. A movable side end plate 12b is provided at the right end of the insulating cylinder 11b. One end of the movable side end plate 12b is airtightly connected to the movable side end plate 12b. The other end of the bezel 17 is airtightly connected to the movable side conductive rod 16b. The movable side conductive rod 16b has a fixed side electrode 15a.
The movable-side electrode 15b opposed to is attached, and the inside of the vacuum container 1 thus configured is set to a high vacuum.
A mounting base 18 is integrally mounted on the movable side end plate 12b by welding or the like.
One end of the metal airtight container 21 is provided on the free end side of the seal member 2
2a is airtightly connected, and a mechanical portion is slidably led out from the other end of the airtight container 21 via a seal member 22b while maintaining airtightness. More specifically, the movable-side conductive rod 16b is slidably led out via the seal member 22b while maintaining airtightness with the airtight container 21. Therefore, the inner peripheral surface side of the bellows 17 communicates with the inside of the airtight container 21 to form the airtight chamber 2, which is separated from the surrounding insulating gas. Airtight chamber 2 with seal material 22b
The movable-side conductive rod 16b led out is electrically connected to the main circuit via a current collector (not shown), and the mandrel 19 provided at the center of the movable-side conductive rod 16b has an operating device (not shown). It is connected. The vacuum valve configured as described above includes, for example, as shown in FIG. 10, insulating containers 61a, 6b, and 6c in which a high-pressure insulating gas 6 is hermetically sealed.
And 62 to be installed and used in an electrically insulated state from these closed containers. In the same figure, the main circuit conductor and the operating mechanism connected via a vacuum valve are not shown.

As described above, the airtight chamber 2 is closed by the bellows of the vacuum container 1.
By surrounding and integrally mounting the groove 17, vacuum pressure acts on the outer peripheral surface side of the bellows 17, but the surrounding high pressure insulating gas 6 shown in FIG. You can turn it off. Therefore, when air or gas having an intermediate pressure between the pressure of the insulating gas 6 and the vacuum pressure is enclosed in the airtight chamber 2, the pressure difference acting on the inner and outer peripheral surfaces of the bellows 17 becomes smaller than in the conventional case. If you can extend its mechanical life and expect the same mechanical life,
By increasing the pressure of the insulating gas filled in the hermetically-sealed container that houses the whole, a gas-insulated vacuum circuit breaker with a higher pressure can be realized.

2 and 3 are a longitudinal sectional view and a lateral sectional view showing a vacuum valve which is an essential part of a gas insulated vacuum circuit breaker according to another embodiment of the present invention. The structure of the vacuum container 1 is shown in FIG.
Since it is almost the same as the embodiment shown in FIG. 5, the same components are designated by the same reference numerals, detailed description thereof will be omitted, and only different configurations will be described.

The airtight container 21 in this embodiment is shown in FIG.
As compared with the above case, the movable side conductive rod 16b extends in the axial direction to increase the volume of the airtight chamber 2, and the current collector 3 is arranged in the airtight chamber 2. The current collector 3 includes a current collector 31 electrically connected to the movable side conductive rod 16b in a slidable relationship, a current collector 32 connected to a main circuit conductor outside the hermetic chamber 2, and the current collector 31. And a conductor 33 connecting between the conductive parts 32. The conductive part 32 extends in the direction perpendicular to the axial direction of the movable side conductive rod 16b while being kept airtight by the seal 22c, and is led out from the airtight chamber 2. There is. The distance between the current collector 31 in the current collector 3 and the seal 22b of the airtight container 21 is larger than the maximum separation distance between the fixed electrode 15a and the movable electrode 15b.

If the distance between the current collector 31 and the seal 22b is made larger than the maximum separation distance between the fixed electrode 15a and the movable electrode 15b as described above, the following advantages can be obtained.
That is, since the movable conductive rod 16b maintains its electrical connection by sliding with the current collector 31 during the opening / closing operation, the surface thereof is roughened by the sliding of both. However, when the seal 22b is arranged in the above-mentioned positional relationship, the movable side conductive rod 16
The rough surface of b does not always reach the seal 22b and is located in the hermetic chamber 2. Therefore, the movable side conductive rod 16b
The rough surface does not reach the seal 22b and adversely affects the airtightness in the same portion. In addition, the current collector 3 is connected to the airtight chamber 2
By installing inside, the dust in the high-pressure gas will collect dust in the current collector 3.
It is also possible to prevent the deterioration of the current collection performance due to adhesion to the. Furthermore, since the current collector 31 and the like are stored in the airtight chamber 2 as described above, the volume of the airtight chamber 2 is increased. Therefore, when the movable side electrode 15b is driven in the opening direction through the mandrel 19 and the movable side conductive rod 16b by an operation device (not shown), the airtight chamber 2 corresponding to the bending of the bellows 17 is driven.
Although the internal volume is reduced and the pressure in the airtight chamber 2 is increased, this pressure increase can be suppressed because the volume in the airtight chamber 2 is relatively increased.

In order to suppress the pressure rise in the airtight chamber 2,
A bottomed cylinder is arranged on the outer peripheral portion of the movable conductive rod 16b shown in FIG. 1, and the bottom portion thereof is airtightly connected to the movable conductive rod 16b so that the cylindrical portion of the bottomed cylinder maintains airtightness. While in a slidable relationship, the seal 2 of the airtight container 21
2b may be arranged. According to this structure, the bottomed cylinder also moves in the same direction by the movement of the movable conductive rod 16b in the opening direction to increase the volume in the airtight chamber 2, so that the amount corresponding to the bending of the bellows 17 is increased. Even if the volume in the airtight chamber 2 is reduced, this can be offset.

4 and 5 are vertical and horizontal sectional views showing a vacuum valve which is a main part of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention, which are shown in FIGS. 2 and 3. Since the vacuum valve is an improved one, the same parts are designated by the same reference numerals, detailed description thereof will be omitted, and only different parts will be described.

A mounting base 18 is attached to the movable end plate 12b.
The open end of the metal bottomed airtight container 21 is sealed through the
The airtight chamber 2 is formed by being airtightly connected via the rule material 22a. In the airtight chamber 2, a current collector 3 electrically connected to the movable conductive rod 16b and a part of the link mechanism 4 are incorporated. This link mechanism 4 is a seal member 22b.
Airtight chamber 2 is made rotatable by maintaining airtightness by
The central axis 41 led out and the central axis 41 in the airtight chamber 2
And a lever 41a connected to the core bar 19 via a connecting pin 23 at its free end side, and a central shaft 4 outside the airtight chamber 2.
1 and a lever 41b coupled to this lever 41
A drive rod 42 connected to an operating device (not shown) is connected to the free end of b. Therefore, when the drive rod 42 is driven to the right in the open circuit direction by an operation device (not shown), the lever 41b and the central shaft 41 rotate clockwise, and the core bar 19 and the movable side conductive rod 16b are connected via the lever 41a. Drive in the open circuit direction.

According to the above-described embodiment, the airtight state in the airtight chamber 2 during the opening / closing operation is that the linear movement of the movable conductive rod 16b is held by the seal member 22b in the previous embodiment. On the other hand, the rotational movement of the central shaft 41 is held by the seal member 22b. This airtightness is easier in the latter rotary motion, so that
Further, the same effect as that of the embodiment shown in FIG. 3 can be expected, and the reliability of maintaining the airtightness of the airtight chamber 2 can be improved. Further, as can be seen from the above-mentioned embodiments, the airtight chamber 2
It suffices to slidably draw out from the airtight container 21 that forms the airtight container 21 with the mechanical portion such as the movable side conductive rod 16b connected to the movable side electrode 15b and the central shaft 41.

FIG. 6 is a vertical sectional view showing a vacuum valve which is a main part of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention, which is an improvement of the vacuum valve shown in FIG. The same reference numerals are given to the objects, detailed description thereof will be omitted, and only different parts will be described.

The structure of the airtight chamber 2 is the same as that shown in FIG. 1, and a gate valve 24 for exhaust is attached to the airtight container 21 forming the airtight chamber 2. Since the airtight container 21 is a rigid body, the gate valve 24 can be easily attached by means such as welding. Since the gate valve 24 is attached to the airtight chamber 2 as described above, the airtight chamber 2 can be charged and exhausted after the vacuum valve is assembled, and the airtight chamber 2 can be evacuated and then filled with an insulating gas. You can Therefore, the pressure in the hermetic chamber 2 can be very easily maintained at a pressure intermediate between the pressure of the insulating gas around the vacuum valve and the pressure in the vacuum container 1, and in this way, the bellows can be maintained. The pressure difference acting on the inner and outer peripheral surfaces of 17 becomes smaller than before, and its mechanical life can be extended. If the same mechanical life is expected, the insulating gas filled in the hermetically sealed container that houses the whole It becomes possible to realize a gas-insulated vacuum circuit breaker with higher pressure by increasing the pressure.

FIG. 7 is a vertical sectional view showing a vacuum valve which is an essential part of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention. An airtight connection between the mounting base 18 and one end of the airtight container 21. The details of the section are shown. In this embodiment, a seal material 22a is interposed between the mounting base 18 and the airtight container 21, and a bolt 25a and a nut 25b are used on the anti-airtight chamber 2 side of the seal material 22a to prevent airtightness. This is what constitutes the connection part. According to this embodiment, the workability of attaching the airtight container 21 and the workability of disassembling can be improved.

FIG. 8 is a vertical sectional view showing a vacuum valve which is an essential part of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention. In the embodiment shown in FIG. 7, a mounting base 18 and an airtight container 21 are provided. One end of each of them is airtightly connected by a bolt 25a and a nut 25b, but in this embodiment, the mounting base 18 and the airtight container 21 are welded together and the seal material is omitted. Since it is the same as the embodiment shown in FIG. 6, the same components are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 9 is a vertical sectional view showing a vacuum valve which is an essential part of a gas insulated vacuum circuit breaker according to still another embodiment of the present invention. In the embodiment shown in FIGS. 1 and 2 to 8, the vacuum valve is used. After the assembly as described above, the mounting base 18 was welded to the movable side end plate 12b. However, in this embodiment, the mounting base 18 is mounted to the movable side end plate 12b at the same time as the vacuum valve is assembled in the furnace.
Is brazed and fixed. After that, the airtight chamber 2 is shown in FIG.
It is formed by the method shown in. According to this structure, since the mounting base 18 of the airtight chamber 2 is already mounted when the vacuum valve is completed, the number of working steps can be reduced.

[0026]

As described above, in the gas insulated vacuum circuit breaker according to the present invention, one end of the airtight container 21 communicating with one peripheral surface side of the bellows of the vacuum valve is airtightly connected to provide an airtight chamber. , The movable conductive rod 16b or the mechanical portion such as the central shaft is slidably led out from the airtight chamber while keeping the airtightness, and the pressure in the airtight chamber is an intermediate pressure between the vacuum container and the surrounding insulating gas. Therefore, with a simple structure, the pressure of surrounding high-pressure insulating gas is not directly applied to the bellows of the vacuum valve as in the past to prevent its mechanical life from being shortened, and the surrounding insulation It is possible to increase the pressure of the characteristic gas to enable high voltage.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a vacuum valve of a gas insulated vacuum circuit breaker according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a vacuum valve of a gas insulated vacuum circuit breaker according to another embodiment of the present invention.

3 is a cross-sectional view of the vacuum valve shown in FIG.

FIG. 4 is a vertical sectional view showing a vacuum valve of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention.

5 is a cross-sectional view of the vacuum valve shown in FIG.

FIG. 6 is a vertical cross-sectional view showing a main part of a vacuum valve of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view showing a main part of a vacuum valve of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention.

FIG. 8 is a vertical cross-sectional view showing a main part of a vacuum valve of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention.

FIG. 9 is a vertical cross-sectional view showing a main part of a vacuum valve of a gas-insulated vacuum circuit breaker according to still another embodiment of the present invention.

FIG. 10 is a vertical sectional view of a gas insulated vacuum circuit breaker according to an embodiment of the present invention.

FIG. 11 is a vertical sectional view showing a vacuum valve of a conventional gas-insulated vacuum circuit breaker.

FIG. 12 is a vertical cross-sectional view showing another conventional gas-insulated vacuum circuit breaker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Airtight chamber 3 Current collecting part 4 Lever mechanism 6 Insulating gas 12b Movable side end plate 15a Fixed side electrode 15b Movable side electrode 16b Movable side conductive rod 17 Bellows 18 Attachment base 21 Airtight container 22a, 22b Seal material 24 Gate valve 31 Current collector 32 Conductive part 41 Central axis

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shunkichi Endo 7-1-1 Omika-cho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Yukio Kurosawa 7-chome, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi Ltd. Hitachi Research Laboratory

Claims (6)

[Claims] 1. A vacuum valve is arranged in an airtight container filled with an insulating gas, and the vacuum valve is connected to a movable electrode of a pair of separable electrodes, and the vacuum valve. In a gas-insulated vacuum circuit breaker provided with a bellows which holds the vacuum state in the valve and allows the operation of the movable side electrode, an airtight container airtightly connected to the vacuum valve is provided to provide one of the bellows. Forming a hermetic chamber that communicates with the peripheral surface side, and slidably leading out a mechanism section that connects the movable side electrode and the operating device from the hermetic container while maintaining hermeticity, and the hermetic chamber is A gas-insulated vacuum circuit breaker, characterized in that the pressure is set to an intermediate pressure between the inside of the vacuum valve and the insulating gas. 2. The mechanism according to claim 1, wherein a mechanism portion connecting the movable side electrode and the operating device has a movable side conductive rod connected to the movable side electrode, and the movable side conductive rod is connected to the movable side conductive rod. A gas insulated vacuum circuit breaker, which is slidably led out from the airtight container while maintaining airtightness. 3. The mechanism according to claim 1, wherein the mechanism portion connecting the movable side electrode and the operating unit is a movable side conductive rod connected to the movable side electrode, and a portion located in the airtight container. And a central shaft that connects the movable side conductive rod to the movable-side conductive rod and connects the portion located outside the airtight container to the operation device, and the central shaft is slidable while maintaining airtightness from the airtight container. A gas-insulated vacuum circuit breaker characterized by being introduced in 1. 4. The method according to claim 2 or 3,
In the airtight container, provided is a current collector that is composed of a current collector electrically connected to the movable-side conductive rod, and a conductive part connected to the current collector and led out of the airtight container while keeping airtight. A gas-insulated vacuum circuit breaker characterized by that. 5. The airtight container according to claim 2, wherein a current collector electrically connected to the movable side conductive rod is provided in the airtight container, and airtightness is maintained outside the airtight container by being connected to the current collector. A current collecting part consisting of a conductive part led out from the airtight container, and a distance from the airtight container of the movable side conductive rod to the current collector is larger than the maximum separation distance between the electrodes. A gas-insulated vacuum circuit breaker. 6. The gas-insulated vacuum circuit breaker according to claim 1, wherein the airtight container is provided with a gate valve.