JPH03110730A - Puffer gas circuit breaker - Google Patents

Abstract

PURPOSE:To obtain a circuit breaker having high breaking performance by forming plural exhaust passages by means of plural exhaust holes each communicated from the hollow opening of a movable contact to a free space, in that end face portion of a puffer cylinder which is on the opposite side of a fixed piston. CONSTITUTION:A gas exhaust passage that has conventionally been formed of a hollow portion in the axial direction of a driving rod 111 is changed; i.e., that end face portion of a puffer cylinder 5 which is on the opposite side of a fixed piston is thickened and plural exhaust holes 5B each communicated from the hollow opening of a movable contact 4 to a free space are provided through the end face portion. Thus gas heated by an arc separates into plural exhaust passages from the hollow opening of the movable contact 4 and is vented through the plural exhaust passages 5B so that the gas is promptly discharged to the free space; each of the plural exhaust passages is therefore shortened and exhaust resistance is decreased and so a large quantity of gas is smoothy exhausted and excellent breaking performance is obtained with a high insulation recovery voltage between electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a buffer type gas circuit breaker, particularly to the structure of a gas exhaust port in an arc extinguishing chamber thereof.

[Conventional technology]

Buffer type gas circuit breakers compress arc extinguishing gas and spray this compressed gas into the opening gap of the interrupting part to extinguish the generated arc and interrupt large currents. SF & gas are extremely superior, and are even used in ultra-high pressure, large-capacity circuit breakers.

FIG. 4 is a vertical cross-sectional view showing the main structure of a conventional buffer type gas circuit breaker, and FIG. 5 is a vertical cross-sectional view showing the state in the middle of the opening operation in FIG.

In FIG. 4, SF at diffused pressure is used as the arc-extinguishing gas.

A cylindrical metal container 1 filled with gas includes a fixed contact 3 supported from the left side of the metal container 1 via an insulator 2, a movable contact 4 that can be separated from the fixed contact 3, and a movable contact 4 that can be separated from the fixed contact 3. An interlocking buffer cylinder 5, a buffer chamber 6fJ in the buffer cylinder 5, a fixed piston 8 supported from the right side of the metal container 1 via an insulating tube 7, and a movable contact 4.
A first insulating nozzle 9 surrounds the movable contact 4 and guides the gas compressed in the buffer chamber 6 into the separation gap between the fixed contact 3 and the movable contact 4 by moving the movable contact 4 in the X direction when the current is cut off. A second insulating nozzle 90 is provided on the side opposite to the fixed contact of the movable contact 4 so as to pass through the buffer chamber 6 in the central axis direction, and supplies the gas heated by the arc between the fixed and movable contacts to the metal container 1. An exhaust passage 11C consisting of a hollow part 11^ and a discharge port 11B for discharging to the free space 10 inside.
A cylindrical drive rod 11 with The movable contactor which is the movable part that has become 4. First insulating nozzle 9. The second insulating nozzle 90 and the buffer cylinder 5 integrated with the drive rod 11 move in the X direction.

In the opening operation of the circuit breaker configured in this way, if the fixed contact 3 does not escape from the throat portion 9A of the first insulating nozzle 9, the fixed contact 3 is moved by the fixed piston 8 in the buffer chamber 6 as shown in FIG. An arc is generated in the separation gap 13 by the compressed gas flow 14A that blows the separation gap 13 between the fixed contact 3 and the movable contact 4 through the gap between the first insulating nozzle 9 and the second insulating nozzle 90 from the blowing hole 5A. 1
The gas heated by the arc 13A is discharged through the exhaust passage 11C into the free space 7 1o as gas flows 14B and 14G.

As the interrupting current increases, the arc 13A becomes larger and tends to block the exhaust gas inlet of the hollow portion 11A of the exhaust passage 11C, so that the gas flow 14A from the buffer chamber 6 tends to become difficult to flow. For this purpose, the buffer chamber 6
The gas pressure inside increases as the breaking current increases. Such an arc extinguishing method, that is, a method in which the inlet side of the exhaust passage 11c is somewhat blocked by the arc 13A at the initial stage of current interruption, thereby increasing the pressure rise in the buffer chamber 6 and extinguishing the arc, It is called the Pannor type, which comes from the meaning of ``Pannor type'', and is used for large current circuit breakers because it can spray a large amount of gas onto the arc 13A when the fixed contact 3 escapes from the throat part 9A of the first insulating nozzle 9. ing.

[Problem to be solved by the invention]

However, as mentioned above, in the conventional device, the hollow part 11A of the driving iron 11 is configured as the gas exhaust passage 11C, and the exhaust passage 11c becomes long in the axial direction in order to secure the volume of the buffer chamber 6. In order to reduce exhaust resistance, it is necessary to increase the inner diameter of the hollow portion 11A, and for this purpose, the outer diameters of the buffer cylinder 5 and the fixed piston 8 must be increased, and as a result, the outer diameter side surface 5D of the buffer cylinder 5 and the metal In order to ensure the insulation distance Z from the inner wall of the container 1, the metal container becomes larger, and the weight of the buffer cylinder 5 also increases, resulting in a disadvantage that the drive device (not shown) also becomes larger.

An object of the present invention is to provide a circuit breaker that is small and has high breaking performance with a small driving force by changing the configuration of the exhaust passage.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, a fixed contact and a movable contact that can be opened are provided in a metal container filled with an arc-extinguishing gas, and a buffer cylinder that is interlocked with the movable contact. a fixed piston that forms a buffer chamber within the buffer cylinder; an insulating nozzle that surrounds the movable contactor and guides the gas compressed in the buffer chamber into the gap between the fixed and movable recontactors; and the movable contactor. In the puff-nor type gas circuit breaker, the exhaust passage is provided on the opposite side of the fixed contact element and guides the gas heated by the arc in the separation gap to the free space in the metal container. The end face of the cylinder on the side opposite to the fixed piston shall be comprised of a plurality of exhaust holes communicating from the hollow opening of the movable contact to the free space, and the exhaust hole shall be formed outward from the central axis side of the end face of the buffer cylinder. The exhaust hole shall penetrate radially toward the radial side, and the exhaust hole shall penetrate radially from the center axis side of the end face of the buffer cylinder halfway toward the outer diameter side, and then bend at a right angle from halfway to the outside. It shall be formed by penetrating each on the radial side.

[Effect]

According to the configuration of the present invention, the conventional hollow part formed in the axial direction of the drive rod as a gas exhaust passage is changed, and the end face part of the buffer cylinder on the side opposite to the fixed piston is thickened, and this end face part Since a plurality of exhaust holes are provided that communicate with the free space from the hollow opening of the movable contact, the gas heated by the arc is divided into a plurality of exhaust passages from the hollow opening of the movable contact and passes through the exhaust opening. It exits and is immediately discharged into free space. Since the exhaust passage is shortened, exhaust resistance is reduced, a large amount of gas can be smoothly exhausted, and excellent interrupting performance with a high insulation recovery voltage between electrodes can be obtained.

In addition, by providing the exhaust hole radially through the end face of the buffer cylinder from the central axis side toward the outer diameter side,
Since the length of the exhaust hole is minimized, the exhaust resistance per exhaust hole is minimized. In addition, by providing the exhaust hole from the center axis side of the end face of the buffer cylinder to the outer diameter side (towards the outer diameter side), the exhaust hole is radially penetrated halfway, and then bent at a right angle from halfway through to the outer diameter side. The gas flow exhausted into the free space has a velocity component in the circumferential direction, and agitation is promoted by friction of this gas flow with the outer peripheral surface of the buffer cylinder.

〔Example〕

The present invention will be explained below based on examples.

FIG. 1 is a longitudinal sectional view showing a main part of a buffer type gas circuit breaker according to an embodiment of the present invention in a state in the middle of an opening operation, and FIG. 2 is a sectional view taken along the line A-A in FIG. 1. It is.

In FIG. 1, the thickness of the end face portion 5C of the buffer cylinder 5 on the side opposite to the fixed piston is set to be thick. A gas exhaust passage is formed by providing a plurality of exhaust holes 5B.Detailed explanations are omitted by using the same reference numerals for the same parts as in the conventional device.The shape of the exhaust hole 5B is, for example, As shown in FIG. 2, four are provided radially, avoiding communication with the spray holes 5A.

In the embodiment configured as described above, the buffer chamber 6
The gas flow 14A blown out through the blowing hole 5A is heated by the arc 13A, and the hollow opening 4 of the movable contact 4 is heated by the arc 13A.
A becomes a gas flow 140 and passes through four exhaust holes 5B,
It becomes a gas flow 14E and is discharged into the free space 1o. The exhaust passage is the hollow part 11 of the drive rod 11 in the conventional device.
Since it is shorter than A, the exhaust resistance is reduced, and when the fixed contact 3 escapes the throat part 9A of the first insulating nozzle 9, the gas that blows the arc 13A can be smoothly exhausted, and the current is interrupted. The insulation recovery voltage between the poles (separation gap 13) becomes high.

Furthermore, according to the present invention, the hollow portion 11A of the drive rod 11 provided in the conventional device is not required in the drive rod 111, so even a thinner drive rod 111 can have sufficient mechanical strength. buffer cylinder 5
The outer diameter of the fixed piston 8 is also reduced, and the metal container 1 can be made smaller as well, and the weight of the buffer cylinder 5 is also reduced, so the driving force of the drive device (not shown) is also reduced, allowing the drive device to be made smaller.

In FIG. 2, the gas exhaust hole 5B is made so that the width W of the hole is increased (or the number of holes is increased to the extent that it does not communicate with the blowing hole 5A), so that the gas exhaust resistance is further reduced. It is possible to adjust and further improve the blocking properties.

FIG. 3 is a sectional view of a different embodiment taken along the line A-A in FIG. Penetrate it and bend it at right angles from the middle to form the outer diameter side surface 5D.
This is an example in which it is formed penetrating through.

With this configuration, the gas flow 140 from the hollow opening 4A of the movable contact 4 is directed through the four bent exhaust holes 5.
B, the gas becomes a gas flow 1411 and is discharged into the free space 10 substantially along the tangential direction of the outer diameter side surface 5D of the buffer cylinder 5. Therefore, after the gas flow 14E is discharged into the free space IO, it is stirred by friction with the outer diameter side surface 5D of the buffer cylinder 5 that is being driven in the X direction, so that it mixes well with the cooled gas in the free space 10. It is possible to prevent a decrease in the dielectric strength between the buffer cylinder 5 and the metal container 1 due to the discharged heated gas.

〔Effect of the invention〕

As mentioned above, this invention has a structure in which a plurality of exhaust holes are provided in the end face of the buffer cylinder on the side opposite to the fixed piston as gas exhaust passages, communicating from the hollow opening of the movable contact to the free space. In this device, the hollow part of the drive rod is formed as an exhaust passage, and the outside diameter of the buffer cylinder increases by that amount. However, it is now possible to use a thinner drive rod, which makes it possible to use a thinner drive rod. This has the effect of making the metal container and drive device smaller than before.

Furthermore, in this invention, the exhaust passage is shorter than the conventional device.
In addition, the width and number of exhaust passages can be adjusted, so
It is possible to provide an excellent performance circuit breaker with low gas exhaust resistance and high insulation recovery voltage between electrodes.

Furthermore, the hollow part of the drive rod provided in conventional devices is no longer necessary, and the cylindrical drive rod can be made into a round rod, so even a thinner drive rod can have sufficient mechanical strength. The outer diameters of the buffer cylinder and fixed piston are reduced, making it possible to downsize the metal container and drive device.

In addition, by providing the exhaust hole radially through the end face of the buffer cylinder from the central axis side toward the outer diameter side,
Since the length of the exhaust holes is minimized, the exhaust resistance per exhaust hole is minimized, so reducing the number of exhaust holes reduces the man-hours required to manufacture the exhaust holes, contributing to lower circuit breaker costs. Effects can be obtained. In addition, by providing the exhaust hole in a radial manner from the center axis side of the end face of the buffer cylinder toward the outer diameter side, and then bending at a right angle from halfway through to the outer diameter side, the exhaust hole The gas flow exhausted from the buffer cylinder into the free space has a velocity component in the circumferential direction, and this gas flow is stirred by friction with the outer peripheral surface of the buffer cylinder and mixes well with the cooled gas in the free space. An effect is obtained in that it is possible to prevent a decrease in dielectric strength between the buffer cylinder and the metal container due to the exhausted heated gas.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a state in the middle of an opening operation in the main part configuration of a pan-foot type gas circuit breaker according to an embodiment of the present invention, and FIGS. 2 and 3 are at the A-A position in FIG. 1. FIG. 4 is a longitudinal sectional view showing the main structure of a conventional puff-nor type gas circuit breaker, and FIG. 5 is a longitudinal sectional view showing a state in the middle of the opening operation in FIG. 4. l: Metal container, 2: Insulator, 3: Fixed contact, 4: Movable contact, 4A: Hollow mouth, 5: Buffer cylinder, 5A
:Blowing hole, 5B: Exhaust hole, 5C: End face, 5D=Outside surface, 6: Buffer chamber, 7: Insulating pipe, 8: Fixed piston, 9: First insulation nozzle, 90: Second insulation nozzle,
9Ai slot part, lO: free space, 11.111:
Drive rod, 11A: Hollow part, IIB: Exhaust port, 11
C: Exhaust passage, 12: Insulating rod, 13: Separation gap, 1
3A: Arc, 14A, 14B, 14C, 140, 14
H: 2nd BM Figure 3

Claims (1)

[Claims] 1) A metal container filled with arc-extinguishing gas includes a fixed contact and a movable contact that can be opened, a buffer cylinder interlocked with the movable contact, and a buffer inside the buffer cylinder. a fixed piston forming a chamber; an insulating nozzle that surrounds the movable contact and guides the gas compressed in the buffer chamber into the gap between the fixed and movable contacts; and a counter-fixed contact of the movable contact. In the buffer type gas circuit breaker, the exhaust passage is provided on the opposite side of the buffer cylinder to the side opposite to the fixed piston, and the exhaust passage is provided on the opposite side of the buffer cylinder and guides the gas heated by the arc in the separation gap to the free space in the metal container. A buffer type gas circuit breaker comprising a plurality of exhaust holes on an end face portion thereof communicating from the hollow opening of the movable contact to the free space. 2) The buffer type gas circuit breaker according to claim 1, wherein the exhaust hole extends radially through the end face of the buffer cylinder from the central axis side toward the outer diameter side. 3) The exhaust hole is characterized in that the exhaust hole penetrates radially from the central axis side of the end face of the buffer cylinder to the outer diameter side up to a certain point, and then bends at a right angle from the middle and passes through each part towards the outer diameter side. The buffer type gas circuit breaker according to claim 1.