JPH05234476A - Puffer-type gas circuit breaker - Google Patents

Abstract

PURPOSE:To lower the resilient force against a puffer cylinder and at the same time provide a puffer-type gas circuit breaker having good circuit breaking properties. CONSTITUTION:A puffer cylinder 6 having a shaft 6a and a piston 7 are fitted each other in the way they can slide freely to form a puffer chamber 8 and the puffer cylinder 6 is so connected with an operational apparatus as to compress an extinguishable gas as a spraying gas in the puffer chamber 8 following the circuit breaking operation. Then, in the middle of the circuit breaking operation, the puffer chamber 8 is shrinked only to the fitting part of the puffer cylinder 6 with a small pressure receiving surface area and the piston 7a with small pressure receiving surface area and continuously it is compressed. Meanwhile, the other part of the puffer chamber 8 is released to ambient gas space by a communicating means 10 and in this way the puffer cylinder's pressure receiving surface area for spraying an extinguishable gas which works as a resilient force against the circuit breaking operation force of the operational apparatus is changed together with the circuit breaking operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a puffer-type gas circuit breaker, and more particularly to a puffer-type gas circuit breaker using a spring operating device whose operating force decreases with opening operation.

[0002]

2. Description of the Related Art Generally, a puffer type gas circuit breaker constitutes a gas compression device called a puffer chamber by slidably fitting a puffer cylinder and a piston, and a puffer cylinder is driven by an operating device. The arc extinguishing gas in the puffer chamber is compressed. An arc is generated due to the separation between the contacts, and when the large current is interrupted, the arc-extinguishing gas in the vicinity thermally expands to a high pressure due to the arc and flows into the puffer chamber.

Therefore, in this type of puffer type gas circuit breaker, a reaction force acts on the puffer cylinder in the direction opposite to the shutoff operation direction by the high-pressure arc-extinguishing gas in the puffer chamber during the shutoff operation. Become. When a large-sized actuator that generates a large operating force is used, this reaction force does not pose a problem, but due to the downsizing of the actuator or maintenance-free operation, the spring that has been stored like a spring actuator is released. When an operating device in which the operating force decreases with movement is used, the breaking speed decreases due to the reaction force.

To prevent this, Japanese Patent Publication No. 57-324
In the puffer-type gas circuit breaker described in Japanese Patent Publication No. 52-52, the entire puffer chamber is exposed to the outside during the shutoff operation, except for a gas blowing flow path that guides the high-pressure gas in the puffer chamber to the arc generated between the contacts. A bypass flow path that opens to the surrounding gas space is formed, and the entire pressure in the puffer chamber is released to the outside via the bypass flow path to reduce the above reaction force.

[0005]

However, in the conventional puffer type gas circuit breaker, since the entire puffer chamber is opened to the outside during the breaking operation, the arc extinguishing gas in the puffer chamber is compressed after this point. Otherwise, the gas spraying on the arc is reduced and the breaking performance is reduced. An object of the present invention is to provide a puffer-type gas circuit breaker that reduces the reaction force against the puffer cylinder and has an excellent breaking performance.

[0006]

In order to achieve the above-mentioned object, the present invention forms a puffer chamber from a puffer cylinder and a piston slidably fitted together, and, together with a shutoff operation, an arc-extinguishing gas in the puffer chamber. Is formed by connecting the puffer cylinder to an operating device so as to compress the puffer cylinder for blowing, and the shut-off operation is performed on the pressure receiving area of the puffer cylinder for blowing the arc-extinguishing gas that acts as a reaction force against the breaking operation force of the operating device. The feature is that it is changed so as to reduce with.

[0007]

In the puffer type gas circuit breaker according to the present invention, as described above, the pressure receiving area of the puffer cylinder for blowing the arc-extinguishing gas, which acts as a reaction force against the breaking operation force, is changed so as to be reduced along with the breaking operation. , Even if the operating force is attenuated along with the shutoff operation, the reaction force also decreases, so
A good stroke characteristic can be obtained, and since the arc-extinguishing gas in the puffer chamber whose volume is reduced is continuously compressed, it is possible to obtain a puffer type gas circuit breaker with excellent breaking performance without lowering the blowing characteristic. it can.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a puffer type gas circuit breaker in a closed state according to an embodiment of the present invention. The movable contactor 4 facing the fixed contactor 2 is connected to an operating device (not shown) via a hollow puffer cylinder shaft 6a. The puffer cylinder 6 coupled to the puffer cylinder shaft 6a constitutes a gas compression device having a puffer chamber 8 slidably fitted to the piston 7, and is provided on the inner surface of the fixed contactor 2 side end thereof. Is a small pressure receiving area puffer cylinder 6
b is formed, and a communicating means 10 such as a slit is formed on the sliding surface of the puffer cylinder 6 located on the side opposite to the fixed contactor with respect to the small pressure receiving area puffer cylinder 6b.
On the other hand, the piston 7 has a small pressure receiving area puffer cylinder 6b.
A small pressure-receiving area piston 7a corresponding to is formed so as to project toward the fixed contactor 2 side. The puffer cylinder 6 has an insulating nozzle 22 surrounding the movable contactor 4 and a movable main contactor 23.
The fixed main contactor 1 that is in contact with the movable main contactor 23 is provided on the outer periphery of the insulating nozzle 22. In addition, the above-mentioned shut-off portion is configured in a closed container (not shown) filled with arc extinguishing gas.

In the illustrated closed state, the puffer cylinder 6 and the piston 7 form one puffer chamber 8, the movable main contact 23 and the fixed main contact 1 are in contact, and the fixed contact 2 and the movable contact 4 are in contact with each other. Are in contact. However, when a cutoff command is given and the shaft 6a is driven to the right by an operation device (not shown), the arc-extinguishing gas in the puffer chamber 8 is compressed, and first, the movable main contact 23 is fixed. 1, the movable contact 4 is separated from the fixed contact 2, and an arc 15 is generated between the separated movable contact 4 and the fixed contact 2 as shown in FIG. This arc 1
The high-pressure arc-extinguishing gas compressed in the puffer chamber 8 is blown to the blower 5, and the blown gas reaching the surrounding gas space through the throat portion of the insulating nozzle 22 and the hollow portion of the shaft 6a as indicated by the arrow. A flow is formed, but when the current to be interrupted is a large current, the arc causes the surrounding arc extinguishing gas to expand and increase in pressure, further increasing the pressure in the puffer chamber 8. On the other hand, the operating device gradually attenuates the spring force by releasing the stored spring together with the breaking operation. After that, the reaction force represented by the product of the pressure receiving area of the puffer cylinder 6 and the pressure is more than the output of the spring of the operating device. Can be too large.

However, in the middle of the shutoff operation, the small pressure receiving area piston 7a comes to fit into the small pressure receiving area puffer cylinder 6b as shown in FIG. 2, and the small pressure receiving area piston 7a and the small pressure receiving area puffer cylinder 6b are provided. While the arc-extinguishing gas in the puffer chamber 8 is continuously compressed, the other part of the puffer chamber 8 is connected to the communicating means 1 as shown in FIG.
Open to the surrounding gas space behind the piston by 0,
The pressure receiving area for blowing the arc-extinguishing gas that receives the reaction force in the puffer cylinder 6 changes with the stroke as shown in FIG. 4 and becomes smaller.

FIG. 5 shows the pressure characteristic in the puffer chamber 8 at the time of the above-mentioned shut-off operation together with the stroke characteristic.
As can be seen from the figure, the pressure P of the arc-extinguishing gas in the puffer chamber 8 increases with the stroke S as shown by the dotted line.
Before the pressure P of the arc extinguishing gas in the puffer chamber 8 becomes excessively large, the small pressure receiving area piston 7a is fitted into the small pressure receiving area puffer cylinder 6b as shown in FIG. The arc-extinguishing gas in the puffer chamber 8 in which the volume formed by the piston 7a and the small pressure receiving area puffer cylinder 6b is reduced is continuously compressed as indicated by the pressure P, and the cylindrical cross-sectional area of the puffer cylinder travels as in the conventional case. The pressure rises above the pressure P1 when it does not change. However, since the other part of the puffer chamber 8 is opened to the surrounding gas space by the communication means 10 as shown in FIG. 3, the pressure receiving area of the puffer cylinder 6 which receives a reaction force is increased along with the stroke S as shown in FIG. Get smaller. Therefore, the stroke S in FIG. 5 is shown by the dotted line from the middle,
Unlike the conventional stroke S1 shown by the solid line, the blocking speed of the blocking section movable part such as the puffer cylinder 6 does not decrease due to the reaction force.

When the shut-off operation comes to an end and the other part of the puffer chamber 8 is opened to the surrounding gas space by the communicating means 10 as shown in FIG. 3, the amount of the arc-extinguishing gas in the puffer chamber 8 is reduced. , The small pressure-receiving area piston 7a and the small pressure-receiving area puffer cylinder 6b are limited to only the portion formed by fitting, and decrease. However, since the arc extinguishing gas in the part limited by the small pressure receiving area piston 7a and the small pressure receiving area puffer cylinder 6b can be continuously compressed and the high pressure gas can be sprayed to the arc, the spraying effect does not deteriorate. In this way, even if the spring force is attenuated along with the breaking action as in the spring operation device, the pressure receiving area of the compressed high-pressure gas in the puffer cylinder 6 is reduced to reduce the reaction force. A gas circuit breaker can be obtained.

FIG. 6 is a cross-sectional view of a puffer type gas circuit breaker in a shut-off state according to another embodiment of the present invention. In the embodiment described above, the piston 7 in the puffer cylinder 6 is
While the slits are provided on the sliding surface with respect to to form the communicating means 10, in the present embodiment, the slit forming the communicating means 10 is formed on the sliding surface with the piston 7 on the outer circumference of the shaft 6a. .. From the closed state to the middle of the shutoff operation, the puffer chamber 8 including the communication means 10 communicates with the surrounding gas space only through the gas blowing passage in the insulating nozzle 22. However, in the middle of the shut-off operation, the opening 7b formed in the piston 7 is located at a position facing the slit of the communicating means 10, and other than the puffer chamber 8 limited by the small pressure receiving area piston 7a and the small pressure receiving area puffer cylinder 6b. The part is opened to the surrounding gas space through this opening 7b, and the pressure of the part is lowered to the same pressure as the surrounding gas space. Therefore, the pressure receiving area of the high pressure gas in the puffer cylinder 6 can be reduced by the amount corresponding to the same portion, and the reaction force can be reduced. In both of these embodiments, since the communication means 10 is constituted by the slits, it is possible to open a part of the puffer chamber 8 to the surrounding gas space with a blocking operation with a simple structure.

FIG. 7 is a cross-sectional view of a puffer type gas circuit breaker in a shut-off state according to another embodiment of the present invention.
The structure of the puffer type gas circuit breaker in this embodiment is basically the same as that of the embodiment shown in FIG. 1, but the rod-shaped body 14 protruding to the fixed contact 2 side in the small pressure receiving area piston 7a.
Is different in that it is provided. A plurality of the rod-shaped bodies 14 are provided corresponding to the communication holes formed in the puffer cylinder 6 and communicating with the inside of the insulating nozzle 22, and are located in the puffer chamber 8 in the closed state, but at the end of the shutoff state. Through the communication hole described above, so as to fit loosely into the insulating nozzle 22 as shown in the figure. Therefore, when the volume of the puffer chamber 8 is limited by the small pressure-receiving area piston 7a and the small pressure-receiving area puffer cylinder 6b, and the other part of the puffer chamber 8 is opened to the surrounding gas space, the rod-shaped body 14 is moved to the previous embodiment. Then, the gas space in the insulating nozzle 22 which was an uncompressed space is fitted into the insulating nozzle 22 so as to be small, and the puffer chamber 8 reduced by the small pressure receiving area piston 7a and the small pressure receiving area puffer cylinder 6b. The arc-extinguishing gas can be more efficiently compressed, and a good gas spraying effect can be expected.

FIG. 8 is a cross-sectional view of a puffer type gas circuit breaker during a breaking operation according to still another embodiment of the present invention. The puffer type gas circuit breaker in this embodiment is shown in FIG.
The configuration of the embodiment shown in FIG. 6 is further improved. A closing plate 19 is provided in the middle of the shaft 6a communicating with the inside of the hollow portion of the movable contact 4, and the communicating hole 13 is formed on the moving contact 4 side of the closing plate 19. Is formed. For this reason, the hollow portions of the movable contactor 4 and the shaft 6a communicate with the inside of the puffer chamber 8 through the communication hole 13 until the middle of the shut-off operation shown in the figure. Therefore, when the arc 15 is generated by the separation between the contacts 2 and 4, especially when the current to be interrupted is a large current, the surrounding gas expands and becomes high in pressure due to the arc 15, and as shown by the arrow, the puffer Store this in chamber 8. When the shutoff operation further proceeds, the communication hole 13 reaches the back of the piston 7 past the puffer chamber 8 and communicates with the surrounding gas space. After this, the arc-extinguishing gas in the puffer chamber 8 acts on the arc 15 and then flows through the throat portion of the insulating nozzle 22 to the surrounding gas space and the shaft 6a.
It becomes a blowing gas flow reaching the surrounding gas space through the inside of the hollow portion and the communication hole 13.

Also in this embodiment, the puffer chamber 8 constituted by the small pressure receiving area piston 7a, the small pressure receiving area puffer cylinder 6b, the communication means 10 and the like has a pressure receiving portion for blowing arc-extinguishing gas which acts as a reaction force together with the breaking operation. Since the area is reduced, even if the operating force of the operating device is attenuated along with the shutoff operation, good shutoff performance can be exhibited, and the same effect as that of the previous embodiment can be obtained.

FIG. 9 is a cross-sectional view of a puffer type gas circuit breaker during a breaking operation according to still another embodiment of the present invention. In the puffer type gas circuit breaker in the previous embodiment, the pressure receiving area for blowing the arc-extinguishing gas, which acts as a reaction force together with the shutoff operation in the puffer chamber 8, is reduced in two stages. Then, in the puffer chamber 8, the pressure receiving area which acts as a reaction force together with the shutoff operation is continuously reduced. That is, the puffer cylinder 6 is formed in a conical shape so that the cylinder portion on the outer periphery gradually shrinks toward the movable contactor 4 side, and the cross-sectional area of the sliding portion with the piston 7 continuously shrinks with the interruption operation. I have to. On the other hand, in order to make the piston 7 follow such a puffer cylinder 6, as shown in FIG.
7 is urged so as to come into close contact with the inner surface of the puffer cylinder 6, and is constructed just like a diaphragm of a camera.

Therefore, when the puffer cylinder 6 operates in the right shut-off direction together with the shut-off operation, the plate 17 rotates little by little against the spring 20 and reduces its outer diameter to follow the inner surface of the puffer cylinder 6. Therefore, the pressure receiving area of the puffer cylinder 6 that acts as a reaction force against the breaking operation force continuously decreases with the breaking operation. In this way, even if the operating force of the operating device is attenuated along with the breaking operation, the reaction force also decreases in proportion to this, and the stroke does not stagnant or reverse as in the conventional case, It is possible to obtain a puffer type gas circuit breaker having a good breaking performance as in the previous embodiment.

[0019]

As described above, according to the present invention, the pressure-receiving area for blowing the arc-extinguishing gas, which is a reaction force against the actuator in the puffer cylinder during the shut-off operation, is changed. There is no stagnation or backward movement of the stroke even if it is attenuated, and since the arc-extinguishing gas in the puffer chamber that has been reduced can be compressed after that, it is possible to obtain a puffer-type gas circuit breaker with excellent shutoff performance by enhancing the spraying effect. You can

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a puffer type gas circuit breaker in a closed state according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a shutoff operation of the puffer type gas circuit breaker shown in FIG.

FIG. 3 is a cross-sectional view showing the end of the breaking operation of the puffer type gas circuit breaker shown in FIG.

4 is a characteristic diagram showing a change in pressure-receiving area for blowing an arc-extinguishing gas of the puffer cylinder of the puffer type gas circuit breaker shown in FIG. 1.

FIG. 5 is a characteristic diagram showing the pressure in the puffer chamber along with the stroke.

FIG. 6 is a cross-sectional view of a puffer type gas circuit breaker according to another embodiment of the present invention.

FIG. 7 is a sectional view of a puffer type gas circuit breaker according to still another embodiment of the present invention.

FIG. 8 is a sectional view of a puffer type gas circuit breaker according to still another embodiment of the present invention.

FIG. 9 is a sectional view of a puffer type gas circuit breaker according to still another embodiment of the present invention.

10 is a cross-sectional view showing a main part of the puffer type gas circuit breaker shown in FIG.

[Explanation of symbols]

 2 fixed contactor 4 movable contactor 6 puffer cylinder 6a shaft 6b small pressure receiving area puffer cylinder 7 piston 7a small pressure receiving area piston 8 puffer chamber 10 communicating means 13 communicating hole 14 rod-shaped body 15 arc 22 insulating nozzle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Kurosawa 4026 Kujimachi, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hiritsu Manufacturing Co., Ltd.

Claims (7)

[Claims] 1. A puffer chamber is formed from a puffer cylinder and a piston which are slidably fitted together, and the puffer cylinder is used as an operating device so as to compress an arc-extinguishing gas in the puffer chamber for blowing when a shutoff operation is performed. In the connected puffer type gas circuit breaker, the pressure receiving area of the puffer cylinder for blowing the arc-extinguishing gas, which acts as a reaction force against the breaking operation force of the operating device, is changed so as to be reduced together with the breaking operation. Characteristic puffer type gas circuit breaker. 2. The puffer-type gas circuit breaker according to claim 1, wherein the pressure-receiving area of the puffer cylinder for blowing the arc-extinguishing gas is changed in at least two stages so as to be reduced together with the shut-off operation. .. 3. The small pressure receiving area puffer according to claim 1, wherein the puffer chamber is fitted with the pressure receiving area reduced with a shutoff operation, and thereafter the internal arc extinguishing gas is compressed for blowing. It has a cylinder and a small pressure receiving area piston, and a communication means for opening the other part of the puffer chamber to the surrounding gas space together with the fitting of the small pressure receiving area puffer cylinder and the small pressure receiving area piston. Puffer cylinder type gas circuit breaker. 4. The puffer type gas circuit breaker according to claim 3, wherein the communication means is formed on a sliding surface of the puffer cylinder with the piston. 5. The puffer cylinder according to claim 3, wherein the puffer cylinder has a shaft at a central portion thereof, the piston is provided so as to slide between the puffer cylinder and the shaft, and the communication means is the above-mentioned. A puffer type gas circuit breaker characterized in that it is configured on a sliding surface of the shaft with respect to the piston. 6. The puffer according to claim 3, wherein the communication means includes the small pressure-receiving area puffer cylinder and the small pressure-receiving area piston when the puffer cylinder moves a predetermined distance in a shutoff direction. A puffer-type gas circuit breaker characterized in that a portion other than the chamber is constituted by a slit that opens to a surrounding gas space on the back side of the piston. 7. A puffer cylinder having a hollow shaft in the center thereof and a piston are slidably fitted to each other to form a puffer chamber, which is used for blowing an arc extinguishing gas in the puffer chamber together with a shutoff operation. The puffer cylinder is connected to an actuator so as to be compressed, and after the arc-extinguishing gas for spraying is made to act on the arc between the separated contacts, the ambient gas is at least passed through the hollow portion of the shaft. In a puffer type gas circuit breaker adapted to discharge into a space, the shaft is made to communicate the puffer chamber with the hollow portion of the shaft at the initial stage of the blocking operation, and thereafter a communication hole is provided to be opened to the surrounding gas space, The pressure-receiving area of the puffer cylinder for blowing arc-extinguishing gas, which acts as a reaction force against the shut-off operation force of the actuator, was changed so as to decrease with the shut-off operation. Puffer type gas circuit breaker.