JP2010244742A - Gas-blast circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas-blast circuit breaker which, even if an arc-caused blocking phenomenon occurs in an insulating nozzle, effectively gives a spray gas a swirling component to improve large current cut-off performance. <P>SOLUTION: The insulating nozzle 4 is disposed to encircle a contact portion between a fixed arc contact 1 and a movable arc contact 2, and guides a flow of a spray gas to cause it to act on an arc between both arc contacts 1 and 2. The throat 12 of the insulating nozzle 4 has a plurality of swirling component slots 13a to 13n formed circumferentially at almost equal intervals. These swirling component slots 13a to 13n are formed to be tilt against the basic direction of the flow of the spray gas so as to give the spray gas flowing through the slots 13a to 13n an aggressive swirling component. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas circuit breaker that performs arc extinguishing by blowing an arc extinguishing gas compressed during an interruption operation by an insulating nozzle.

  As this type of gas circuit breaker, the arc extinguishing gas is compressed in connection with the breaking operation between the pair of stationary and moving arc contacts, and the arc generated by the breaking between the arc contacts is reduced. On the other hand, there is known a structure in which the compressed gas is blown while being guided by an insulating nozzle to extinguish the arc, and an improvement has been made in order to improve the shut-off performance by effectively blowing the gas flow against the arc. It has been broken. For example, as a conventional gas circuit breaker, a rectifying grid that rectifies the gas flow is formed in a portion located upstream or downstream of the blowing gas flow from the throat portion in the insulating nozzle, so that the stagnation of the gas flow is reduced. Insulating nozzles are used to prevent the generation of a pressure region and improve the small current interruption performance (see, for example, Patent Document 1) or from a compression device that compresses arc-extinguishing gas in connection with the opening operation. An attempt was made to improve the shut-off performance by giving a flow component that rotates in the circumferential direction to the flow path that guides the blowing gas flow to the tip, preventing turbulence and stagnation of the gas flow at the tip of the fixed arc contactor The thing (for example, refer patent document 2) is known.

JP-A-2-98025 JP-A-9-92102

  However, with conventional gas circuit breakers, improvement of the blowing gas flow can be expected for small current interruptions where arc extinguishing is completed when the separation distance between the fixed arc contact and the movable arc contact is small. Sufficient consideration has not been given to a balance with a large current interruption performance such as a short distance interruption (SLF) in which the arc extinguishing is completed after the contact comes out of the throat portion of the insulating nozzle. In other words, the gas circuit breaker described in Patent Document 1 has a configuration that considers a small current interruption, and the insulation nozzle is used when a large current interruption is performed in which arc extinguishing is performed after the fixed arc contactor comes out of the throat portion of the insulation nozzle. When a clogging phenomenon occurs due to an increase in pressure due to the arc in the entire interior, the rectifying grid formed away from the arc hardly affects the rectification of the gas flow. Further, in the gas circuit breaker described in Patent Document 2, it is effective to give a swirl component to the blowing gas flow at the time of large current interruption in which arc extinguishing is performed after the fixed arc contactor comes out of the throat portion of the insulating nozzle. However, until the fixed arc contact comes out of the throat portion of the insulating nozzle, the pressure in the insulating nozzle rises due to the arc. The turning component is not generated at all, and it can hardly be expected to improve the high current interruption performance.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a gas circuit breaker in which a swirl component is effectively applied to a blowing gas even when a clogging phenomenon occurs due to an arc in an insulating nozzle to improve a large current interruption performance.

  In order to achieve the above object, the present invention provides a stationary arc contact and a movable arc contact that form a separable pair, a compression device that compresses arc-extinguishing gas during a breaking operation, and the throat portion inserted through the throat portion. An arc extinguishing gas compressed by the compression device is blown against the arc generated by the separation between the fixed arc contact and the movable arc contact. In the gas circuit breaker including the insulating nozzle for guiding, a swirl component groove is provided in the throat portion of the insulating nozzle to give a swirl component to the blowing gas flow passing through the throat.

  According to the gas circuit breaker of the present invention, when the fixed arc contact comes out of the throat portion of the insulating nozzle, a blowing gas flow through the throat portion is formed. The swirl component is positively imparted in the circumferential direction or toward the central axis of the fixed arc contact by means of a large current interruption by giving almost uniform spraying action and cooling action from the entire circumference of the arc. The performance can be improved. In addition, since the swirl component groove is formed at the throat portion, the effect is not impaired by the clogging phenomenon caused by the pressure rise caused by the arc when a large current is interrupted, and the fixed arc contact exits the throat portion of the insulating nozzle. It always works effectively at the moment.

FIG. 1 is a cross-sectional view showing a state in the middle of breaking of a gas circuit breaker according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional perspective view of an insulating nozzle which is a main part of the gas circuit breaker shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a breaker of a gas circuit breaker according to an embodiment of the present invention.
The interrupting part is configured in a hermetically sealed container filled with an arc extinguishing gas, and the stationary arc contact 1 and the movable arc contact 2 forming a pair are arranged so as to be able to contact and separate, and the stationary arc contact 1 is not shown. The movable arc contact 2 is configured to be opened and closed on its axis via a drive shaft 3 by an operating device (not shown), while being fixed at the position shown by means. The insulating nozzle 4 that surrounds and arranges the contact portion between the fixed arc contact 1 and the movable arc contact 2 in a contact state is disposed so as to surround the movable arc contact 2 and the outer peripheral portion of the movable arc contact 2. It is attached to the puffer cylinder 6 together with the insulating cylinder 5. A fixed main contact 7 supported in the same manner is disposed on the outer peripheral portion of the fixed arc contact 1, and this fixed main contact 7 is against the movable main contact 8 attached to the puffer cylinder 6 at the outer peripheral portion of the insulating nozzle 4. Are arranged opposite to each other.

  The puffer cylinder 6 connected to the drive shaft 3 via the central shaft 9 is arranged in a slidable relationship with the piston 10, and the arc extinguishing in the puffer chamber 11 is related to the shut-off operation by the puffer cylinder 6 and the piston 10. The compression apparatus which compresses sex gas is comprised. The insulating nozzle 4 described above guides the arc-extinguishing gas from the compression device along the inner surface thereof, and is effective to effectively act on the arc generated between the fixed arc contact 1 and the movable arc contact 2. It has a throat portion 12 that is a narrow portion, and the narrowest portion 12 has a turning component groove 13 that will be described in detail later.

  In the charged state, the movable main contact 8 is in contact with the fixed main contact 7, and the fixed arc contact 1 is inserted into the throat portion 12 of the insulating nozzle 4 and is in contact with the movable arc contact 2. The rated current flows mainly through the movable main contact 8 and the fixed main contact 7. The shut-off operation is performed by driving the drive shaft 3 in the shut-off direction shown in the figure with an operating device (not shown). First, the movable main contact 8 is separated from the fixed main contact 7 and then the movable arc contact 2 is fixed. Separated from the arc contact 1. Therefore, an arc is generated with the separation between the arc contacts 1 and 2, and the arc extinguishing gas is compressed in the puffer chamber 11 constituting the compression device in connection with the interruption operation. The compressed blowing gas is guided along the opposed surfaces of the insulating cylinder 5 and the insulating nozzle 4 to act on the arc to extinguish the arc. At the time of interrupting a large current such as SLF interruption, after the fixed arc contactor 1 exits the throat portion 12 of the insulating nozzle 4 as shown in the figure, a main blowing gas flow passing through the throat portion 12 is formed and then the arc is extinguished. Is done.

The blowing gas flow when the large current is interrupted will be further described.
The blowing gas flow is basically formed by supplying the arc extinguishing gas compressed in the puffer chamber 11 into the insulating nozzle 4 until the fixed arc contact 1 exits the throat portion 12 of the insulating nozzle 4. Is affected by the arc generated between the arc contacts 1 and 2, the pressure in the insulating nozzle 4 rapidly rises and becomes closed, and the gas flow is stagnated. However, when the fixed arc contact 1 exits the throat portion 12 of the insulating nozzle 4, a blowing gas flow through the throat portion 12 is formed. The blowing gas flow at this time is formed under the influence of the rising pressure due to the arc in the insulating nozzle 4, the inner surface of the insulating nozzle 4, and the swirling component groove 13 in addition to the puffing action by the compression device.

FIG. 2 is an enlarged perspective view showing only the throat portion 12 of the insulating nozzle 4.
Here, the right side is the upstream side of the blowing gas flow from the compressor, and the left side is the downstream side of the blowing gas flow. The throat portion 12 is formed with a plurality of swirl component grooves 13a to 13n at substantially equal intervals in the circumferential direction by life ring processing, and these swirl component grooves 13a to 13n are formed in the basic flow direction of the blowing gas flow, That is, it has an inclination with respect to the axis of the fixed arc contact 1 and is formed in an oblique straight line or spiral. The swirl component grooves 13a to 13n give a positive swirl component to the blowing gas flow flowing through the swirl component grooves 13a to 13n.

  Since the swirl component grooves 13a to 13n are formed in the throat portion 12 of the insulating nozzle 4, the swivel component grooves 13a to 13n are formed in the insulating nozzle 4 even before the fixed arc contact 1 exits the throat portion 12 of the insulating nozzle 4. This will not adversely affect the communication. In other words, at the beginning of the breaking operation at the time of breaking a large current before the fixed arc contact 1 exits the throat portion 12, the temperature of the arc generated between the fixed arc contact 1 and the movable arc contact 2 or the arc is exposed. Under the influence of the gas generated from the insulating nozzle 4, the inside of the insulating nozzle 4 shows a sudden pressure rise and becomes a closed state, the pressure rise in the insulating nozzle 4 is maintained, and used for subsequent spraying to the arc. Can do.

  Moreover, since the swirl component grooves 13 a to 13 n are formed in the throat portion 12 of the insulating nozzle 4, the pressure increase in the insulating nozzle 4 can be maintained until the fixed arc contact 1 exits the throat portion 12.

  However, when the shut-off operation proceeds and the fixed arc contact 1 exits the throat portion 12 of the insulating nozzle 4, a blowing gas flow through the throat portion 12 is formed. The swirling component flow is positively applied to the blowing gas flow by the swirling component grooves 13a to 13n in the circumferential direction or toward the central axis of the fixed arc contact 1 and affects the blowing gas flow in other portions. give. For this reason, as shown in FIG. 1, the blowing gas flow acts on the arc while rotating spirally around the central axis of the fixed arc contact 1, and is almost uniform from the entire circumference of the arc. A spraying action, a cooling action, etc. can be given. Moreover, the same effect | action can be given also to the front-end | tip part of the fixed arc contact 1, and a large current interruption | blocking performance can be improved in this way.

  As can be seen from the above description, the gas circuit breaker according to the present embodiment has the swirl component grooves 13a to 13n formed in the throat portion 12 of the insulating nozzle 4, so that the insulating nozzle is in the initial stage of operation when a large current is interrupted. 4 is not affected even if a clogging phenomenon occurs in the configuration 4, and the turning component grooves 13a to 13n act on the blowing gas flow when the shut-off operation proceeds and the fixed arc contact 1 exits the throat portion 12 of the insulating nozzle 4. It is. In the case where the swirl flow is formed from the beginning of the shutoff operation by means formed on the upstream side of the blowing gas flow from the throat portion as in the prior art, the effect is impaired by the blockage phenomenon in the early stage of the shutoff operation, but such inconvenience is completely It does not occur and a stable effect can always be expected.

  The above-described swirl component grooves 13a to 13n can be arbitrarily set with respect to the basic flow direction of the blowing gas flow, the number and depth thereof, and in any case, are formed at substantially equal intervals in the circumferential direction. Is desirable.

  The gas circuit breaker according to the present invention is not limited to the configuration shown in FIG. 1 but can be applied to other configurations.

DESCRIPTION OF SYMBOLS 1 Fixed arc contact 2 Movable arc contact 3 Drive shaft 4 Insulation nozzle 5 Insulation cylinder 6 Puffer cylinder 7 Fixed main contact 8 Movable main contact 9 Center shaft 10 Piston 11 Puffer chamber

Claims (1)

  A fixed arc contact and a movable arc contact that form a pair that can be separated; a compression device that compresses the arc-extinguishing gas during the breaking operation; and the fixed arc contact and the movable arc contact that are inserted through the throat portion thereof. A gas barrier comprising an insulating nozzle that surrounds the contact portion and guides the arc extinguishing gas compressed by the compression device to blow the arc generated by the separation between the stationary arc contact and the movable arc contact A gas circuit breaker characterized in that a swirl component groove for imparting a swirl component to the sprayed gas flow passing through the throat is formed in the throat portion of the insulating nozzle.

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