JP2000311561A - Gas-blast circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-blast circuit breaker capable of cutting off a large current without enlarging the volume of space in a movable cylinder and without increasing a mechanical burden on an operating mechanism part. SOLUTION: A space in a movable cylinder 8 is partitioned into two chambers, a compression chamber Sb with a volume reduced by an opening motion and a pressure rising chamber Sa with a volume not reduced by an opening motion, the compression chamber Sb and the pressure rising chamber Sa communicate with each other via check valves 12, 13, and an exhaust hole 14 is provided in a side surface of an operation rod 5. In the early stage of an opening motion, the compression chamber Sb communicates with a middle part in the operation rod 5 via the exhaust hole 14, and in the late stage of the opening motion. the exhaust hole 14 is positioned nearer to an operating mechanism, (in the rear) than a puffer piston 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas circuit breaker installed to cut off a large current in a transmission and substation system.

[0002]

BACKGROUND OF THE INVENTION Gas circuit breaker is blown into the arc extinguishing gas such as SF ₆ for extinguishing an arc generated by the large current interruption. As shown in FIG. 10, the conventional gas circuit breaker includes a fixed arc contact 1 and a fixed current contact 2.
, A movable contact part 11 composed of a movable arc contact 3, a movable energizing contact 4, an operating rod 5, an insulating nozzle 6, and a movable cylinder 8, and a puffer piston 7 fixed to a stationary part. And extrudes the arc-extinguishing gas stored in the movable cylinder inner space (puffer chamber) S surrounded by the movable cylinder 8, the operating rod 5 and the puffer piston 7, and is generated between the arc contacts 1 and 3. Spray the arc to extinguish the arc.

[0003]

However, in the above-mentioned conventional gas circuit breaker, when it is necessary to blow a high-pressure gas to the arc for a long time, such as when cutting off a large current,
The volume of the space S in the movable cylinder must be increased, and a stronger compressive force is required by the puffer piston 7,
The mechanical load on the operation mechanism increases. Therefore, miniaturization was difficult.

Accordingly, the present invention has been made to solve the above-mentioned problems, and has disclosed a gas capable of cutting off a large current without increasing the volume of the movable cylinder internal space S and without increasing the mechanical load on the operating mechanism. It is intended to provide a circuit breaker.

[0005]

In order to achieve the above object, the present invention divides the space inside a movable cylinder into a boosting chamber and a compression chamber, thereby reducing the volume compressed by a puffer piston and reducing the driving energy. It is characterized in that it can be reduced.

That is, a first aspect of the present invention has a movable and fixed arc contact in a container filled with an arc-extinguishing gas such as SF ₆ gas, and drives the movable arc contact to form the two arc contacts. At the same time, the movable cylinder is driven and the arc extinguishing gas in the movable cylinder inner space (puffer chamber) is compressed by the puffer piston, and the compressed arc extinguishing gas is generated between the two arc contacts. In the gas circuit breaker, which extinguishes and shuts off the arc by blowing the arc, the movable cylinder space is divided into a boosting chamber whose volume is reduced by the opening operation and a compression chamber whose volume is not reduced by the opening operation. Is characterized in that the volume to be compressed is reduced.

Thus, even in a case where heat due to the arc at the time of interruption cannot be expected as in the case of medium current interruption, it is sufficient to increase the pressure in the compression chamber, and a pressure that can be interrupted by the gas in the compression chamber is obtained. Can be. On the other hand, in the case of a large current interruption, the temperature due to the arc becomes extremely high, and after increasing the internal gas pressure of the compression chamber, the internal pressure of the pressure raising chamber is increased by opening a check valve between the pressure chamber and the pressure increasing chamber. Thus, after the gas in the compression chamber is blown, the high-pressure gas can be supplied from the pressurizing chamber, and the arc-extinguishing gas can be continuously blown for a long time. In addition, the reduction in the volume to be compressed allows the driving force of the piston to be smaller than before, and the operating mechanism can be downsized.

According to a second aspect of the present invention, when the operation of the check valve is such that the pressure in the compression chamber is a predetermined value, for example, 10% higher than the pressure in the pressure increasing chamber.
At least one check valve that opens when the pressure increases is provided, and at least one check valve that opens when the pressure in the boosting chamber exceeds the pressure in the compression chamber is provided. It is characterized by the following.

According to the second aspect of the present invention, the pressure in the compression chamber does not exceed a certain value, and the excess load on the puffer piston can be reduced. In addition, the high-pressure gas can be supplied from the pressurizing chamber even after the gas pressure in the compression chamber is lowered, and the high-pressure gas can be sprayed for a long time.

A third aspect of the present invention is characterized in that the closing plate provided on the check valve is urged in the closing direction by at least two or more springs. According to the third aspect of the present invention, it is possible to change the open / close condition of the check valve by changing the elastic force of the spring, and to change the pressure in the booster chamber according to the cutoff condition.

According to a fourth aspect of the present invention, the angled closing plate provided at the check valve portion is fixed at one end and free at the other end,
The free end is biased by a spring. The operation according to the fourth aspect is the same as that of the third aspect.

A fifth aspect of the present invention is characterized in that the closing plate provided in the check valve portion is an elastic body, and the communication hole is opened and closed by the elastic force of the closing plate. According to the fifth aspect of the invention, the opening and closing conditions can be changed by changing the material of the closing plate.

A sixth aspect of the present invention is characterized in that the check valve is embedded in a partition plate between the compression chamber and the pressure increasing chamber. According to the invention of claim 6, the moving distance of the puffer piston can be lengthened, and the gas in the compression chamber can be blown longer.

A seventh aspect of the present invention is characterized in that the pressurizing chamber has a role of a puffer piston and two exhaust holes are provided on a side surface of the operating rod. According to the seventh aspect of the present invention, it is possible to take in the gas pressurized by the arc into the compression chamber at an early stage of opening and exhaust the gas at a late stage of opening.

According to an eighth aspect of the present invention, at least one check valve through which gas can flow out of the pressurizing chamber is provided on the insulating nozzle side of the pressurizing chamber. According to the invention of claim 8, the gas in the pressure increasing chamber can be directly blown to the arc without passing through the compression chamber.

A ninth aspect of the present invention is characterized in that the puffer piston is made of a material having a melting point higher than 700 ° C., or at least the material facing or facing the operating rod is coated or coated with such a material. According to the ninth aspect of the present invention, the puffer piston can withstand high-temperature gas caused by the arc.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Configuration) A first embodiment of the present invention will be described with reference to FIG. FIG. 1A shows the closed state of the gas circuit breaker of the present embodiment. A hollow operation rod 5 having a pair of fixed and movable arc contacts 1 and 3 in a container (not shown) filled with an arc-extinguishing gas such as SF ₆ gas and connected to an operation mechanism with an insulating rod or the like. A movable arc contact 3 is provided on the front surface of the movable cylinder 8 on the side of the fixed arc contact 1, and a movable arc contact 3 is provided between the movable cylinder 8 and the movable arc contact 3. An insulating nozzle 6 is coupled to the movable energizing contact 4 and the like so as to hold and surround the flow path, and the operating rod 5 and the movable cylinder 8
Between them, a puffer piston 7 supported by a container (not shown) with an insulator is inserted.

The space inside the movable cylinder 8 is a cylindrical partition plate.
15 divides the compression chamber Sb into which compression is performed by the puffer piston 7 and the pressurization chamber Sa where compression is not performed. The partition plate 15 is provided with at least two communication holes communicating the two chambers Sa and Sb. In the communication holes, the pressure in the compression chamber Sb is set to a predetermined value (for example, 10%) higher than the initial filling pressure in the pressure increasing chamber Sa. ) At least one first check valve 13 that opens when the pressure increases and at least one second check valve 12 that opens when the pressure in the boosting chamber Sa is higher than the pressure in the compression chamber Sb.
One is provided. The position of the second check valve 12 is in front of the puffer piston 7 even in the fully opened state. The operation rod 5 has an exhaust hole 14.

(Operation) FIG. 1B shows the gas circuit breaker of the present embodiment in the middle of opening. Exhaust hole of operation rod 5
Numeral 14 makes the space inside the operation rod 5 communicate with the inside of the compression chamber Sb in the initial stage of the opening operation. Then, contacts 1,3
The gas heated and increased in pressure by the arc between them is sent into the compression chamber Sb, and the pressure in the compression chamber Sb increases.
In addition, the gas in the compression chamber Sb is compressed by the puffer piston 7. In this process, when the pressure in the compression chamber Sb exceeds the pressure in the pressure raising chamber Sa and the condition for opening the first check valve 13 is satisfied, the first check valve 13 opens, and the pressure in the pressure chamber Sb is increased.
The high-pressure gas flows into the pressure chamber, and the pressure in the boosting chamber Sa rises.

FIG. 1C shows a fully opened state.
In the latter half of the opening operation, the exhaust hole 14 is
The gas moved to the mechanism side (rearward) and the pressure increased by the arc is exhausted from between the puffer piston 7 and the operation rod 5. Further, since the gas volume of the compression chamber Sb is maintained even at the fully opened position, the pressure does not increase excessively. When the pressure in the compression chamber Sb decreases and falls below the pressure in the pressure raising chamber Sa, the second check valve 12 opens, and the gas in the pressure raising chamber Sa is supplied to the compression chamber Sb.

(Effect) In the case of current interruption, it is not possible to expect an increase in gas pressure due to an arc. Even in such a case, the gas circuit breaker of the present embodiment is provided with the compression chamber Sb smaller than the conventional movable cylinder internal space S, so that a gas pressure sufficient for shutoff can be obtained, and the gas in the compression chamber Sb It is possible to shut off only with this. Further, the reaction force acting on the puffer piston 7 is also reduced.

In the case of interrupting a large current, the gas is supplied from the pressurizing chamber Sa even after the gas pressure in the compression chamber Sb drops, and the arc-extinguishing gas having a sufficient pressure for shutting off is continuously blown between the arc contacts 1 and 3. it can. Further, the operation of the first check valve 13 prevents the blowing pressure from becoming excessive.

As described above, in the gas circuit breaker of the present embodiment, the puffer piston 7
Can reduce the volume of compression, and can reduce the mechanical load on the operating mechanism.

FIGS. 2, 3 and 4 are cross-sectional views of various check valves applicable to the gas circuit breaker according to the first embodiment. The first check valve shown in FIG. As 13,
It can also be used as the second check valve 12.

In the check valve shown in FIG. 2, the compression chamber Sb
Communication hole 25 formed in the partition plate 15 for separating the pressure chamber Sa from the pressure rise chamber Sa.
A closing plate 21 provided thereon, and a spring 22 for urging the closing plate 21
Is provided. The closing plate 21 is pressed against the partition plate 15 by the spring 22, and closes a communication hole 25 provided in the compression chamber Sb and the pressure increasing chamber Sa.

In the configuration shown in FIG. 2, when a pressure difference occurs between the compression chamber Sb and the boosting chamber Sa during the opening operation, the closing plate 21 is pushed up, the communication hole 25 is opened, and a gas flows. Conditions for this opening can be changed depending on the length of the bolt 23 and the strength of the spring 22, and an appropriate opening condition can be set according to the condition of the current to be interrupted.

FIG. 3 is a cross-sectional view of a check valve having a different structure, showing a state when the check valve is closed. A spring 22 for urging the closing plate 21 to a partition plate 15 for dividing the compression chamber Sb and the pressure boosting chamber Sa.
Are provided by bolts 23. This makes the closing plate
Reference numeral 21 is pressed against the partition plate 15, and closes a communication hole 25 provided between the compression chamber Sb and the boosting chamber Sa.

FIG. 4 is a sectional view of a check valve having a further different structure, showing a state when the check valve is closed. A leaf spring 24 for urging the closing plate 21 is provided on a partition plate 15 that separates the compression chamber Sb from the pressure boosting chamber Sa.
Installed by. As a result, the leaf spring 24 is pressed against the partition plate 15, and closes the communication hole 25 provided in the compression chamber Sb and the pressure increasing chamber Sa. The check valve shown in FIGS. 3 and 4 can also obtain the same operation and effect as the check valve shown in FIG.

FIGS. 5 and 6 show the structure of the boosting chamber Sa which can be adopted in this embodiment. The partition plate 15 is fixed to the movable cylinder 8 with a screw 30 or a press contact 31. FIG. 7 shows a gas circuit breaker according to a second embodiment. This is one in which a cylindrical portion of the movable cylinder 8 has a double wall, and a first check valve 13 and a second check valve 12 are embedded in a partition plate 15 which is an inner wall separating the compression chamber Sb and the pressure raising chamber Sa. It is. The configuration of the boosting chamber Sa is the same as in the first embodiment.

According to this embodiment, the same effects as those of the first embodiment can be obtained, and the check valves 12 and 13 do not interfere with the movement of the puffer piston 7, so that the compression chamber Sb
The gas inside can be compressed and sprayed effectively.

FIG. 8 shows a gas circuit breaker according to a third embodiment of the present invention, in which a second check valve is provided on the operation rod 5 side of the boosting chamber Sa.
13 and a second check valve 12 on the distal end side.
The configuration of the boosting chamber Sa and the structure of the check valve are the same as those in the first embodiment. According to this embodiment, the gas in the boosting chamber Sa can be directly blown to the arc without passing through the compression chamber Sb.

FIG. 9 shows a fourth embodiment of the present invention.
The movable cylinder 8 is the same as the conventional one, and the puffer piston 7 has a double wall. The space between the outer side wall and the inner side wall is defined as a boosting chamber Sa, and the space between the front surface of the puffer piston 7 and the movable cylinder 8 is defined as a compression chamber Sb. Further, check valves 12 and 13 are provided on a partition plate 15 which forms the front surface of the puffer piston 7. The operating rod 5 is provided with an exhaust hole 26 and an exhaust hole 27. The exhaust hole 27 is located at the position of the puffer piston 7 and closed at the initial stage of opening. The exhaust hole 26 is inside the compression chamber Sb, and the inside of the operation rod 5 and the inside of the compression chamber Sb communicate with each other through the exhaust hole 26. Exhaust hole 26 during late opening
Moves to the position of the puffer piston 7 and is closed.
27 moves out of the range of the puffer piston 7, and the inside of the operation rod 5 and the space in the container forming the outer periphery of the gas circuit breaker communicate with each other through the exhaust hole 27.

According to the present embodiment, it is possible to obtain an effect that gas pressurized by an arc is taken into the compression chamber at an early stage of opening and exhausted at a late stage of opening. In the gas circuit breaker of the present invention, since the temperature of the puffer piston 7 becomes high, the puffer piston 7 is made of a material having a melting point of more than 700 ° C., such as iron, titanium, copper, tungsten, chromium, zirconia, or the like. At least the operating rod 5
It is better to apply or coat the above-mentioned material on the portion facing the surface.

[0034]

According to the gas circuit breaker of the present invention, the boosting chamber and the compression chamber are defined in the space inside the movable cylinder, so that the space inside the movable cylinder is not enlarged, and the mechanical structure of the operating mechanism is not increased. A large current can be cut off without increasing the burden.

[Brief description of the drawings]

FIGS. 1A and 1B show a gas circuit breaker according to a first embodiment of the present invention, wherein FIG. 1A shows a closed state, FIG.

FIG. 2 is a diagram illustrating a first example of a gas circuit breaker according to an embodiment of the present invention.
The figure of the check valve of the example of FIG.

FIG. 3 shows a second embodiment provided in the gas circuit breaker according to the embodiment of the present invention.
The figure of the check valve of the example of FIG.

FIG. 4 is a diagram illustrating a third example of the gas circuit breaker according to the embodiment of the present invention.
The figure of the check valve of the example of FIG.

FIG. 5 is a diagram showing a first configuration example of a booster chamber provided in the gas circuit breaker according to the embodiment of the present invention.

FIG. 6 is a diagram showing a second configuration example of the boosting chamber provided in the gas circuit breaker according to the embodiment of the present invention.

FIG. 7 is a diagram showing a gas circuit breaker according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a gas circuit breaker according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a gas circuit breaker according to a fourth embodiment of the present invention.

FIG. 10 is a diagram showing a conventional gas circuit breaker.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixed arc contact, 2 ... Fixed energizing contact, 3 ... Movable arc contact, 4 ... Movable energizing contact, 5 ... Operating rod,
6 ... insulating nozzle, 7 ... puffer piston, 8 ... movable cylinder, 10 ... fixed contact part, 11 ... movable contact part, 12 ... second check valve, 13 ... first check valve, 14 ... exhaust hole, 15 … Partition plate, 21…
Closing plate, 22: spring, 23: bolt, 24: leaf spring, 25: communication hole, 26, 27: exhaust hole, 30: screw, 31: pressure contact, S: space in movable cylinder (puffer chamber), Sa: boost Chamber, Sb ... compression chamber.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hitoshi Mizoguchi 2-1 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Hamakawasaki Plant (72) Inventor Katsumi Suzuki No. 2, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 F-term in Toshiba Hamakawasaki Plant (reference) 5G001 AA01 AA08 BB04 CC03 DD02 DD04 EE01 EE11 FF03 FF06 GG17

Claims (9)

[Claims] 1. A fixed contact portion, a movable contact portion, and a puffer piston are provided in a container filled with an arc-extinguishing gas, and the fixed contact portion has a fixed arc contact and a fixed energizing contact. The movable contact portion includes a hollow operating rod connected to an operating mechanism by an insulating rod or the like, a movable arc contact connected to a distal end of the operating rod, and a concentric outer periphery connected to the operating rod. A movable cylinder provided in a shape,
It has an insulating nozzle attached to the tip of the movable cylinder, the puffer piston is supported by the container via an insulator and is inserted between the operating rod and the movable cylinder, and at the tip the space inside the movable cylinder is A gas circuit breaker in which a gas flow path formed between the insulating nozzle and the movable arc contact is in communication with the movable cylinder space, wherein the movable cylinder space has a volume reduced by an opening operation. It is defined as two chambers, a compression chamber that is reduced and a booster chamber whose volume is not reduced by the opening operation,
The compression chamber and the pressurization chamber communicate with each other via a check valve, and an exhaust hole is provided on a side surface of the operation rod. At the beginning of the opening operation, the compression chamber and the hollow portion in the operation rod are closed. A gas circuit breaker, wherein the gas circuit breaker communicates via an exhaust hole, and the exhaust hole is located closer to the operation mechanism than the puffer piston in a later stage of the opening operation. 2. The first check valve, which opens when the pressure in the compression chamber is higher than the pressure in the compression chamber by a predetermined value or more, is higher than the pressure in the compression chamber. 2. A second check valve which opens when in a state.
The described gas circuit breaker. 3. The gas circuit breaker according to claim 2, wherein the check valve has a closing plate, and the closing plate is biased by a spring in a closing direction. 4. The gas circuit breaker according to claim 3, wherein one end of the closing plate is fixed and the other end is a free end. 5. The gas circuit breaker according to claim 2, wherein the check valve has a closing plate and utilizes an elastic force of the closing plate. 6. The gas circuit breaker according to claim 1, wherein the check valve is embedded in a partition plate between the compression chamber and the pressure increasing chamber. 7. The pressurizing chamber is formed by being fixed to the head of the puffer piston, and the first exhaust hole and the second exhaust hole are formed on the side surface of the operating rod.
An exhaust hole is provided, the second exhaust hole is located closer to the operation mechanism than the first exhaust hole, and at the beginning of opening, the second exhaust hole is closed by a puffer piston and the compression chamber and the operation rod hollow portion are separated from each other. The space inside the container and the hollow part of the operating rod are connected by the second exhaust hole that communicates with the first exhaust hole and moved to the outside of the puffer piston in the later stage of opening, and the first exhaust hole is closed by the puffer piston. The gas circuit breaker according to claim 1, wherein: 8. The gas circuit breaker according to claim 1, wherein a check valve through which gas can flow out of the pressurizing chamber is provided on the insulating nozzle side of the pressurizing chamber. 9. The puffer piston is made of a material such as iron, titanium, copper, tungsten, chromium, zirconia or the like having a melting point of more than 700 ° C., or has at least a surface coated or coated with said material facing the operating rod. The gas circuit breaker according to claim 1, wherein: