JPH0714534U - Gas circuit breaker - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the arc extinguishing performance of a thermal puffer type gas circuit breaker that also uses magnetic arc drive. In a thermal puffer-type gas circuit breaker that also uses magnetic arc drive, cooling fins 7 are provided in the upper part inside the booster chamber 3, and the direction of arrangement of the cooling fins 7 is adjusted to the direction of gas rotation during magnetic arc drive. Deploy.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thermal puffer type gas circuit breaker that also uses a magnetic arc drive.

[0002]

[Prior art]

 As a technology for extinguishing an arc of a gas circuit breaker, a thermal puffer type gas circuit breaker that also uses magnetic arc drive has been conventionally known. This will be described with reference to FIG. The left half of FIG. 3 shows the closed state of the circuit breaker, and the right half shows the state of the circuit breaker during the breaking operation. The booster chamber 3 is formed by the upper terminal 1 and the outer wall 2. A fixed contact 4, a coil 5, and an arc runner 6 are housed in the booster chamber 3. Further, the outer wall 2 is formed with a nozzle 9 through which the movable contact 8 enters and leaves the pressurizing chamber 3.

The movable contact 8 enters and leaves the booster chamber 3 through the nozzle 9. When the circuit breaker is turned on, the movable contact 8 comes into contact with the fixed contact 4 in the boost chamber 3, and at this time, the nozzle 9 is closed to seal the boost chamber 3. When the current is cut off, the movable contact 8 separates from the fixed contact 4 and goes out of the boost chamber 3 to release the inside of the boost chamber to the outside of the boost chamber.

The fixed contact 4 is electrically connected to the upper terminal 1 by the support rib 10 and is mechanically supported. The space between the support ribs 10 is a gas flow passage 11 through which gas can flow. The fixed contact 4, the coil 5, and the arc runner 6 are electrically connected in series. Next, the operation of the thermal puffer type gas circuit breaker that also uses the magnetic arc drive will be described.

When the left half of the drawing is energized, a current flows between the fixed contact 4 and the movable contact 8 in contact with each other. When the circuit breaker is shut off, the movable contact 8 is moved downward in the figure by an operating mechanism (not shown). When the movable contact 8 separates from the fixed contact 4, the current commutates to the path of the coil 5 and the arc runner 6, and an arc is generated between the arc runner 6 and the movable contact 8. Then, the arc is rotationally driven at high speed around the illustrated central axis by the magnetic field generated by the current flowing through the coil 5.

When the arc rotates inside the pressure increasing chamber 3, the gas inside the pressure increasing chamber 3 is heated to a high temperature and the gas pressure rises. Further, when the arc rotates, gas is relatively blown to the arc to extinguish the arc, and the magnetic arc drive extinguishes the arc. When the movable contact 8 is in the booster chamber 3, the arc extinguishing operation is performed by this magnetic drive.

After that, when the movable contact 8 moves further downward and the tip of the movable contact 8 comes off the nozzle 9 of the booster chamber 3 as shown in the right half of the figure, the high pressure gas inside the booster chamber 3 is indicated by an arrow. As shown in B, it is rapidly ejected through between the nozzle 9 and the movable contact 8. This gas flow causes an arc extinguishing action by a heat puffer that blows out the arc A generated between the arc runner 6 and the movable contact 8.

[0008]

[Problems to be solved by the device]

 In the breaking operation of the circuit breaker described above, the gas discharged from the booster chamber 3 and blown to the arc must be a gas having insulating and arc extinguishing performance. However, when the time from opening to extinguishing becomes long, or when the current becomes large, the gas abnormally heats due to the arc, and the insulation and arc extinguishing performance is lost, making it impossible to extinguish the arc. was there.

An object of the present invention is to improve arc extinguishing performance in a thermal puffer type gas circuit breaker that also uses magnetic arc drive.

[0010]

Means for Solving the Problems In order to achieve the above object, the present invention provides a heat-puffer type gas circuit breaker that also uses magnetic arc drive, with cooling fins provided in the upper part of the boost chamber, and the arrangement of the cooling fins. The direction is arranged according to the rotating direction of the gas when the magnetic arc is driven.

[0011]

[Action]

 According to the above-mentioned means, the gas heated and boosted by the arc energy and accumulated in the boost chamber is deprived of heat by the cooling fins and cooled. For this reason, when the movable contact passes through the nozzle, the gas discharged from the pressurizing chamber through the nozzle has a sufficient arc extinguishing performance, so that the arc extinguishing performance is improved.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross section of the thermal puffer type gas circuit breaker seen from the side. Further, FIG. 2 shows a cross section taken along line YY of FIG. The illustrated blocking unit is housed together with SF6 gas in a container (not shown). The left half of the figure shows the closed state of the circuit breaker, and the right half shows the state when the circuit breaker is closed.

A pressure rising chamber 3 is formed by the upper terminal 1 and the outer wall 2. A fixed contact 4, a coil 5, and an arc runner 6 are housed in the booster chamber 3. Further, cooling fins 7 are provided in the upper part of the booster chamber 3. Further, the outer wall 2 is formed with a nozzle 9 through which the movable contact 8 moves in and out of the boost chamber 3. The movable contact 8 moves in and out of the booster chamber 3 through the nozzle 9. When the circuit breaker is turned on, the movable contact 8 comes into contact with the fixed contact 4 in the boost chamber 3, and at this time, the nozzle 9 is closed to seal the boost chamber 3. When the current is cut off, the movable contact 8 separates from the fixed contact 4 and goes out of the boost chamber 3 to release the inside of the boost chamber to the outside of the boost chamber.

The fixed contact 4 is electrically connected to the upper terminal 1 by the support rib 10 and is mechanically supported. The space between the support ribs 10 is a gas flow passage 11 through which gas can flow. The fixed contact 4, the coil 5, and the arc runner 6 are electrically connected in series. The cooling fins 7 are made of a material having good thermal conductivity such as aluminum and copper, and are arranged on the inner periphery of the outer wall 2 above the pressurizing chamber 3 with a plurality of gaps therebetween, as shown in FIG. In addition to the plate-shaped fins, a mesh-shaped or cotton-shaped cooling fin 7 may be used. Further, the cooling fins 7 are arranged so as to be inclined toward the center so that the gas smoothly flows between the cooling fins 7 in accordance with the direction in which the gas rotates when the magnetic arc is driven. Further, it is preferable that the cooling fin 7 is formed in a curved surface along the gas flow.

Next, the operation of the thermal puffer type circuit breaker that also uses the magnetic arc drive will be described. When the left half of the drawing is energized, the fixed contact 4 and the movable contact 8 come into contact with each other, and the current flows through the path of the upper terminal 1-support rib 11-fixed contact 4-movable contact 8.

During the breaking operation of the breaker, the movable contact 8 is moved downward in the drawing by an operating mechanism (not shown). When the movable contact 8 separates from the fixed contact 4, the current is commutated to the path of the upper terminal 1-support rib 10-coil 5-arc runner 6, and an arc is generated between the arc runner 6 and the movable contact 8. . Then, the arc is rotationally driven at high speed with the magnetic field generated by the current flowing through the coil 5 centered on the central axis in the drawing. As the arc rotates inside the booster chamber 3, the gas inside the booster chamber 3 is heated to a high temperature and the gas pressure rises. Further, when the arc is driven in the gas, the gas is relatively blown to the arc, and the magnetic arc drive extinguishes the arc. When the movable contact 8 is in the booster chamber 3, the arc-extinguishing action by the magnetic drive is performed.

During the above shutoff operation, the gas in the booster chamber 3 is heated and boosted by the arc energy. At the initial stage of arc generation, the pressure-increased gas flows into the pressure-increasing chamber 3 from the hollow portion of the fixed contact 4 through the gas flow path 11 formed between the support ribs 10. After the arc moves to the arc runner 6, the pressure-enhanced gas passes through the outer periphery of the coil 5 in the pressure-increasing chamber 3, passes through the gas flow path 11, and flows out to the hollow portion of the fixed contact 4.

After that, when the movable contact 8 moves further downward and the tip of the movable contact 8 comes off the nozzle 9 of the booster chamber 3 as shown on the right side of the drawing, the high pressure gas inside the booster chamber 3 is discharged from the nozzle 9. And between the movable contact 8 and the movable contact 8, a sudden ejection is performed as shown by an arrow B. This gas flow serves to extinguish the arc A between the arc runner 6 and the movable contact 8 by the heat puffer effect.

The gas blown to the arc at this time is the gas that has been boosted by the arc and accumulated in the boost chamber 3. This gas is boosted by the arc and pushed up to the upper part of the booster chamber 3, where heat is taken away by the cooling fins 7 to be cooled and stored in the booster chamber 3. Further, a part of the cooled and accumulated gas spreads below the booster chamber 3 and cools the gas heated by the arc. Therefore, since the gas discharged from the booster chamber 3 through the nozzle 9 when the movable contact 8 leaves the nozzle 9 has sufficient arc extinguishing performance, the arc extinguishing performance is improved.

Further, since the volume of the gas heated by the arc is reduced by providing the cooling fin 7, it is possible to reduce the volume of the booster chamber 3 with respect to a constant current, and the entire circuit breaker can be reduced. It is effective for downsizing. Further, the cooling fins 7 are arranged such that the arrangement direction thereof is inclined with respect to the direction from the center of the pressurizing chamber 3 toward the outer wall 2, and the inclination direction is made to coincide with the rotation direction of gas by magnetic arc drive. The cooling fins 7 do not obstruct the gas flow, and a smooth gas flow is obtained. Therefore, the gas is cooled quickly, and the arc extinguishing performance is improved.

[0021]

[Effect of device]

 According to the present invention, arc extinguishing performance can be improved in a thermal puffer type gas circuit breaker that also uses magnetic arc drive.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view as seen from the direction of the arrows along the line YY in FIG.

FIG. 3 is a sectional view of a conventional gas circuit breaker.

[Explanation of Codes] 1 ... Upper terminal 2 ... Outer wall 3 ... Booster chamber 4 ... Fixed contact 5 ... Coil 6 ... Arc runner 7 ... Cooling fin 8 ... Movable contact 9 ... Nozzle 10 ... Support rib 11 ... Gas flow path

Claims (1)

[Scope of utility model registration request] 1. A thermal puffer type gas circuit breaker that also uses a magnetic arc drive, wherein cooling fins are provided in the upper part of the pressure boosting chamber, and the arrangement direction of the cooling fins is aligned with the rotation direction of the gas during magnetic arc drive. A gas circuit breaker characterized in that