JPH0520986A - Puffer type gas circuit breaker - Google Patents

Abstract

PURPOSE:To enable arc-extinguishing gas to be sufficiently cooled after exposure to arc without any need of enlarging the diameter and length of a tank in the puffer type gas circuit breaker where high-pressure arc-extinguishing gas is blown to arc generated in a breaker and the arc is thereby suppressed. CONSTITUTION:A bushing 19 to introduce a lead conductor 18 for a stationary contact 2 to the outside of a grounding tank 20, is laid in a direction for both contacts 2 and 6 to close and open. Also, a flow guide 21 for introducing arc- extinguishing gas blown from a nozzle 11 to the inside of the bushing 19 is formed coaxially with both contacts 2 and 6.

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 for extinguishing an arc generated between both contacts during a breaking operation by blowing an arc extinguishing gas.

[0002]

2. Description of the Related Art FIG. 3 is a cross-sectional view showing a conventional puffer type gas circuit breaker disclosed in, for example, Japanese Patent Laid-Open No. 62-262324, in which 1 is a grounded tank filled with arc-extinguishing gas. , 2 and 3 are fixed contacts and fixed arc contacts arranged in this ground tank, 4 is a lead conductor of these fixed contacts 2 and fixed arc contacts 3,
Reference numeral 5 is a bushing for guiding the lead conductor 4 out of the ground tank 1, 6 is a movable contact which comes in contact with and separates from the fixed contact 2 by moving in the direction of the arrow in the figure, and 7 is a movable arc which moves together with the movable contact 6. Contact 3
It is a movable arc contact that comes into contact with and separates from the ground tank 1 and a drive device (not shown).

Reference numeral 8 is a puffer cylinder integrally formed with the movable contact 6, 9 is a piston fitted with the puffer cylinder 8, and 10 is a puffer cylinder 8 and a piston 9.
In the puffer chamber formed by and, the volume is increased or decreased by moving the puffer cylinder 8 on the piston 9 in the direction of the arrow in the figure. Reference numeral 11 denotes a nozzle formed at the tip of the movable contact 6 and communicating with the puffer chamber 10. Reference numeral 12 denotes a lead conductor of the movable contact 6 and the movable arc contact 7.
Is a bushing for leading the lead conductor 12 out of the ground tank 1, and 14 is the lead conductor 4 and the fixed contact 2.
And a fixed metal fitting for connecting the fixed arc contact 3 to the ground tank 1 by an insulating support 15. Reference numeral 16 is a connecting fitting for connecting the lead conductor 12 to the movable contact 6 and the movable arc contact 7, which is fixed to the ground tank 1 by an insulating support 17.

Next, the operation of the conventional puffer type gas circuit breaker configured as described above will be described. First, in a normally-on state, the current introduced from the lead conductor 4 is shunted from the connection fitting 14 to the fixed contact 2 and the fixed arc contact 3, and the movable contact 6 and the fixed contact 2, respectively.
It flows into the connecting fitting 16 through the puffer cylinder 8 and the movable arc contact 7, and is led out of the grounding conductor 1 from the lead conductor 12.

In this state, when an accident occurs in the system and the current is cut off, the movable arc contact 7 is driven in the leftward direction of the arrow in the figure by a drive unit (not shown), and the movable contact 6 and the puffer cylinder 8 are similarly moved. It moves by sliding. With this operation, the movable contact 6 is first separated from the fixed contact 2 and then the movable arc contact 7
Is separated from the fixed arc contact 3.

At this time, an arc is generated between the movable arc contact 7 and the fixed arc contact 3, but the puffer chamber 10 is moved by the leftward movement of the puffer cylinder 8.
, The arc-extinguishing gas in the puffer chamber 10 is compressed to a high pressure, and is blown to the arc through the nozzle 6 to extinguish the arc. The arc-extinguishing gas passes through the movable arc contact 7 on the movable side and passes through the fixed contact 2 on the fixed side to be discharged into the ground tank 1, and the other arc-extinguishing gas in the ground tank 1 is discharged. It is cooled by being mixed with gas.

[0007]

Since the conventional puffer type gas circuit breaker is constructed as described above, the high-temperature, low-density arc-extinguishing gas exposed to the arc during arc extinction is connected to the grounding fitting 4.
If the gas is discharged in the vicinity, the insulation performance between the charging portion on the fixed contact 2 side and the grounding tank 1 deteriorates after the current is cut off. Therefore, the arc-extinguishing gas discharged as described above is in the grounding tank 1. It is necessary to mix and cool with other arc-quenching gas at room temperature, but in order to sufficiently cool this, it is necessary to enlarge the diameter or length of the ground tank 1 to increase the volume, There is a problem that the device becomes large.

The present invention has been made to solve the above problems, and sufficiently cools the arc-extinguishing gas emitted from the nozzle to the arc without increasing the diameter or length of the grounding tank. It is an object of the present invention to provide a puffer-type gas circuit breaker that can be used.

[0009]

[Means for Solving the Problems] Claim 1 according to the present invention
In this puffer type gas circuit breaker, a bushing for guiding the lead-out conductor on the fixed contact side to the outside of the tank is arranged in the contact and separation direction of both contacts, and the arc-extinguishing gas blown from the nozzle is introduced into the bushing. The flow guide is formed coaxially with both contacts, and the puffer type gas circuit breaker of claim 2 is the same as that of claim 1.
Insulation-supported electrodes are formed around the flow guide.

[0010]

The bushing on the fixed contact side of the puffer type gas circuit breaker according to the present invention forms a cooling space in the blowing direction of the arc extinguishing gas, and the flow guide guides the arc extinguishing gas to the cooling space for cooling. . The electrode also relaxes the electric field near the exit of the flow guide.

[0011]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view showing a puffer type gas circuit breaker according to a first embodiment of the present invention. In the figure, the fixed contact 2, the fixed arc contact 3, the movable contact 6, the movable arc contact 7, the puffer cylinder 8, the piston 9, the puffer chamber 10, the nozzle 11, the lead conductor 12, the connection fitting 16 and the insulating support fitting 17 are shown in FIG. Is similar to that of the conventional puffer type gas circuit breaker. Reference numeral 18 denotes a lead conductor of the fixed contact 2 and the fixed arc contact 3, which is arranged coaxially with both contacts 2 and 6. Reference numeral 19 is a bushing for guiding the lead conductor 18 out of the ground tank 20, 21 is a flow guide which is arranged concentrically with the lead conductor 18, and is fixed to the ground tank 20 by an insulating support 22, which is a metal cylinder. Is formed by.

Next, the operation of the puffer type gas circuit breaker according to the first embodiment of the present invention constructed as described above will be described. First, the lead conductor 1 is normally in the closed state.
The current introduced from 8 is shunted to the fixed contact 2 and the fixed arc contact 3, and the movable contact 6, the puffer cylinder 8 and the movable arc contact 7 respectively.
Through the connection metal fitting 16 and is led out of the grounding conductor 20 from the lead conductor 12.

In this state, when an accident occurs in the system and the current is cut off, the movable arc contact 7 is used as in the conventional case.
Is driven in the left direction by an unillustrated driving device, and the movable contact 6 and the puffer cylinder 8 also slide in the same manner. With this operation, the movable contact 6 is first separated from the fixed contact 2, and then the movable arc contact 7 is separated from the fixed arc contact 3.

At this time, although an arc is generated between the movable arc contact 7 and the fixed arc contact 3, the puffer chamber 10 is moved by the leftward movement of the puffer cylinder 8.
, The arc-extinguishing gas in the puffer chamber 10 is compressed to a high pressure, and is blown to the arc through the nozzle 6 to extinguish the arc. This arc-extinguishing gas passes through the movable arc contact 7 on the movable side and is discharged into the bushing 19 through the fixed contact 2 and the flow guide 21 on the fixed side, and is discharged at other room temperature inside the bushing 19 at room temperature. After being cooled by being mixed with the arc-extinguishing gas, it returns to the ground tank 20 again. In this way, since the inside of the bushing 19 acts as a cooling space, it is possible to sufficiently cool the grounding tank 20 and maintain the dielectric strength without increasing the diameter or length of the grounding tank 20. Further, since the flow guide 21 is formed of a metal cylinder, it can also serve as a shield.

Example 2. Second Embodiment FIG. 2 is a sectional view showing a puffer type gas circuit breaker according to a second embodiment of the present invention. In the figure, reference numeral 23 is an electrode that is formed so as to surround the outer periphery of the flow guide 21 and is supported by an insulating support tool 22. As described above, the puffer-type gas circuit breaker according to the second embodiment is different from the puffer-type gas circuit breaker according to the first embodiment shown in FIG. 1 in that the electrode 23 is provided, and the other configurations are exactly the same. .

The puffer type gas circuit breaker in the second embodiment constructed as described above is normally in the closed state and introduced from the lead conductor 18 like the puffer type gas circuit breaker in the first embodiment shown in FIG. The generated electric current flows between both contacts 2 and 6 and both arc contacts 3 and 7,
When the lead-out conductor 12 is led to the outside of the ground tank 20 to interrupt the current due to an accident or the like in the system, the movable contact 6 side is moved to the left in the figure to move between the fixed contact 2 and the movable contact 6. The fixed arc contact 3 and the movable arc contact 7 are opened in this order to complete the breaking operation.

On the other hand, at this time, the arc generated between the arc contacts 3 and 7 is blown out by the high-pressure arc-extinguishing gas which is compressed in the puffer chamber 10 and blown through the nozzle 11. Then, the arc-extinguishing gas exposed to the arc and having a high temperature passes through the movable arc contact 7 on the movable side and is discharged into the bushing 19 through the fixed contact 2 and the flow guide 21 on the fixed side. After being cooled by being mixed with other arc-extinguishing gas in the bushing 19 at room temperature, it returns to the grounded tank 20 again.

As described above, since the inside of the bushing 19 acts as a cooling space, the ground tank 20 can be sufficiently cooled and the dielectric strength can be maintained without increasing the diameter or length of the ground tank 20. Since the electric field near the outlet of the flow guide 21 can be relaxed by disposing the electrode 23, the insulation distance between the flow guide 21 and the bushing 19 can be shortened, and the bushing 19 can be made small in diameter. Can contribute to cost reduction.

[0019]

As described above, according to the present invention, the bushing for leading out the lead conductor on the fixed contact side to the outside of the tank is arranged in the contact / separation direction of both contacts, and the eraser blown from the nozzle is eliminated. A flow guide that guides the arc gas into the bushing is formed coaxially with both contacts, and since electrodes that are insulated and supported around the flow guide are formed, it is possible to increase the diameter of the tank or make it long. It is possible to provide a puffer type gas circuit breaker capable of sufficiently cooling the arc extinguishing gas emitted from the nozzle to the arc.

[Brief description of drawings]

FIG. 1 is a sectional view showing a puffer type gas circuit breaker according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a puffer type gas circuit breaker according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional puffer type gas circuit breaker.

[Explanation of symbols] 2 fixed contacts 6 movable contacts 8 Puffer cylinder 9 pistons 10 puffer room 11 nozzles 18 lead conductor 19 bushings 20 ground tank 21 Flow guide 23 electrodes

Claims (2)

[Claims] 1. A pair of movable and fixed contacts arranged in a tank filled with an arc-extinguishing gas, and arranged along the outer periphery of the movable contact and sliding with the movement of the movable contact. A puffer chamber composed of a piston and a cylinder is provided, and when the contacts are opened, the arc-extinguishing gas compressed in the puffer chamber is blown through a nozzle onto an arc generated between the contacts to extinguish the arc. In the puffer type gas circuit breaker designed to
A bushing for locating the lead conductor on the fixed contact side to the outside of the tank is arranged in the contacting / separating direction of the contacts, and a flow guide for guiding the arc extinguishing gas blown from the nozzle into the bushing. A puffer-type gas circuit breaker characterized by being formed coaxially with both contacts. 2. The puffer type gas circuit breaker according to claim 1, wherein an electrode supported by insulation is formed around the flow guide.