JPH11213823A - Gas-blast circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-blast circuit breaker in which the arc does not burn out a container. SOLUTION: This gas-blast circuit breaker is provided with a fixed electrode 21 mounted to an insulating container 20, a cylindrical body 22 made of a conductive material and mounted to the fixed electrode 21, a fixed contact 23 mounted to the fixed electrode 21, a movable electrode 26 provided with a movable contact 27 contacting with and separating from the fixed contact 23, an arc runner 28 having an arc-traveling surface 28a surrounding the fixed contact 23 and having a cone-shaped surface facing the movable contact 27, and an arc drive coil 25 which is wound around the cylindrical body 22 and one end of which is connected with the fixed electrode 21 and the other end of which is connected with the arc runner 28. Here, a ring body 1 made of an insulating material is provided at the end part of the arc runner 28 facing the movable electrode 26. Accordingly, an arc foot on the arc runner 28 is blocked by the ring body 1, and the arc foot does not shift to the end part of the arc runner 28, even when the arc between the movable contact 27 and the arc runner 28 loops, consequently the arc does not burn out the container 20.

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 for extinguishing an arc in an insulating gas.

[0002]

2. Description of the Related Art A conventional gas circuit breaker is configured as shown in FIG. In the figure, reference numeral 20 denotes a container made of an insulating material, and a fixed electrode 21 is attached to the top of the container 20. Reference numeral 22 denotes a cylindrical body made of a conductive material attached to the fixed electrode 21. Reference numeral 23 denotes a fixed contact attached to the fixed electrode 21. A spring 24 is provided between the back surface of the fixed contact 23 and the cylindrical body 22. The fixed contact 23 is pressed inward. An arc drive coil 25 is wound around the outer periphery of the cylindrical body 22, one end of which is connected to the fixed electrode 21 via the cylindrical body 22, and the other end of which is connected to the arc runner 28. Reference numeral 26 denotes a movable electrode provided with a movable contact 27 which comes into contact with and separates from the fixed contact 23, and has an end connected to an operating mechanism (not shown). 28 is the arc drive coil 25
And an arc runner 28a, which is formed in an annular shape surrounding the fixed contact 23, and has an arc running surface 28a whose surface facing the movable contact 27 is shaped like a mortar. Reference numeral 29 denotes an insulating gas sealed in the container 20. Next, the switching operation of the gas circuit breaker will be described. When the movable electrode 26 is moved in the direction of arrow B by operating an operating mechanism (not shown) from a state (not shown) in which the movable contact 27 of the movable electrode 26 is in contact with the fixed contact 23, the fixed contact 23
An arc is generated between the movable contact 27 and the movable contact 27. further,
When the movable electrode 26 is actuated in the direction of arrow B, as shown in FIG. 2, the arc between the fixed contact 23 and the movable contact 27 is extended, and the arc foot on the fixed contact 23 moves onto the arc runner 28. I do. The arc foot is an arc runner 28
When moving upward, the arc current travels from the movable electrode 26 through the insulating gas 29 and flows to the fixed electrode 21 via the arc runner 28, the arc driving coil 25 and the cylindrical body 22. When an arc current flows through the arc drive coil 25,
Magnetic flux is generated in the arc drive coil 25. The arc D between the movable electrode 26 and the arc runner 28 is rotationally driven in the insulating gas atmosphere by the magnetic flux generated in the arc driving coil 25 to extinguish the arc at zero current. The arc does not extinguish,
When the arc current decreases, the magnetic flux generated in the arc driving coil decreases, and the arc cannot be controlled, and the arc D loops and rotates while contacting the inside of the container. The arc is gradually extinguished while continuing to rotate.

[0003]

However, in the conventional gas circuit breaker, when the arc current between the movable electrode 26 and the arc runner 28 decreases, the magnetic flux generated in the arc driving coil decreases. For this reason, there is a problem that the arc cannot be controlled by the magnetic flux, and the arc D shifts to the tip of the arc runner 28 on the movable electrode side while looping the arc D, and the arc column burns the inside of the container 20. Then, an object of the present invention is to obtain a gas circuit breaker in which an arc does not burn a container.

[0004]

In order to solve the above problems, the present invention provides a container made of an insulating material, a fixed electrode attached to the container, and a cylindrical body made of a conductive material attached to the fixed electrode. A fixed contact attached to the fixed electrode, a movable electrode provided with a movable contact that comes into contact with and separated from the fixed contact, and an arc surrounding the fixed contact and facing the movable contact with a mortar-shaped arc. An arc runner facing a movable electrode in a gas circuit breaker comprising: an arc runner having a running surface; and an arc drive coil wound around the outer periphery of the cylindrical body and having one end connected to a fixed electrode and the other end connected to the arc runner. An annular body made of an insulating material is provided at the end.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of a gas circuit breaker showing an embodiment of the present invention. The same members as those in FIG. 2 are denoted by the same reference numerals, and detailed description is omitted. The basic structure of a gas circuit breaker according to the present invention is the same as that of a conventional gas circuit breaker, but an annular body 1 made of an insulating material such as ceramic is attached to an end of an arc runner facing a movable electrode. The opening / closing operation of the gas circuit breaker having the ring body attached to the end of the arc runner will be described below. When the movable electrode 26 is actuated in the direction of arrow A by operating an operation mechanism (not shown) from a state in which the movable contact of the movable electrode is in contact with the fixed contact of the fixed electrode (not shown), the fixed contact 23 And movable contact 27
And an arc is generated. Further, when the movable electrode 26 is actuated in the direction of arrow A, the arc between the fixed contact 23 and the movable contact 27 is extended as shown in FIG. Move to When the arc foot moves onto the arc runner 28,
An arc current travels from the movable electrode 26 through the insulating gas 29 and flows to the fixed electrode 21 via the arc runner 28, the arc driving coil 25 and the cylindrical body 25. When an arc current flows through the arc drive coil 25, a magnetic flux is generated in the arc drive coil 25. The arc C between the movable electrode 26 and the arc runner 28 is rotationally driven in an insulating gas atmosphere by the magnetic flux generated in the arc driving coil 25, thereby extinguishing the arc at zero current. The arc cannot be extinguished at the current zero point, the arc current becomes small, and the arc C between the movable contact 27 and the arc runner 28 loops while the arc C between the movable contact 27 and the arc runner 28 is shaped like a bowl.
Even if the arc foot moves to the movable electrode side along 8a, the arc foot on the arc runner 28 is prevented from moving to the tip of the arc runner 28 by the annular body 1 made of insulating material, and the center of the arc running surface 28a of the arc runner 28 is prevented. The arc can be extinguished by traveling through the section. Therefore, it is possible to obtain a gas circuit breaker that reliably extinguishes the arc without burning the inside of the container even if the arc C loops.

[0006]

As described above, according to the present invention, the ring made of insulating material is attached to the end of the arc runner.
Even if the arc loops, the arc can be reliably extinguished without the arc column burning the inside of the container.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a gas circuit breaker showing an embodiment of the present invention.

FIG. 2 is a side sectional view of a conventional gas circuit breaker.

[Explanation of symbols]

1 ring, 20 container, 21 fixed electrode, 22
Cylindrical body, 23 fixed contact, 24 spring, 25 arc drive coil, 26 movable electrode, 27 movable contact, 28 arcrunner, 28a arc running surface,
29 Insulating gas

Claims (1)

[Claims] 1. A container made of an insulating material, a fixed electrode attached to the container, a cylindrical body made of a conductive material attached to the fixed electrode, a fixed contact attached to the fixed electrode, and the fixed contact A movable electrode provided with a movable contact that comes in contact with and separates from an arc runner having an arc running surface surrounding the fixed contact and having a surface facing the movable contact in a mortar shape;
An arc drive coil wound around the outer periphery of the cylindrical body and having one end connected to the fixed electrode and the other end connected to the arc runner, wherein an end of the arc runner facing the movable electrode is made of insulating material. A gas circuit breaker characterized in that a ring body is provided.