JP2013115014A - Gas breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a breaker that has a valve structure making a puffer piston compact, and has sufficient breaking performance even with small driving force.SOLUTION: A gas breaker has a movable arc contactor and a fixed arc contactor arranged opposite each other in a sealed container filled with arc suppressing gas. The movable arc contactor is connected to an end of an operation rod while facing the side of the fixed arc contactor. A puffer cylinder is constituted coaxially with the operation rod, and coupled to the operation rod. The puffer piston is inserted into the puffer cylinder to form a puffer chamber. The puffer piston has a compression plate provided with a communication hole linking the interior and exterior of the puffer chamber to each other and a projection part at an inner peripheral part of the compression plate. A valve plate is fitted to the surface of the compression plate on the side of the puffer chamber so as to close the communication hole. The projection part of the compression plate is fitted with a spring receiver, and a coil spring in a truncated cone shape which has a small-diameter-side inner diameter larger than the outer diameter of the projection part of the compression plate is arranged between the spring receiver and valve plate.

Description

Embodiments described herein relate generally to a gas circuit breaker.

As a gas circuit breaker that performs current switching in a power system, a type called a puffer type is widely used. As the insulating medium and arc-extinguishing medium, SF6 gas (sulfur hexafluoride gas) having excellent arc-extinguishing properties and electrical insulation performance is mainly used, but gases other than SF6 gas can be used or various gases can be mixed. Sometimes used.

As the operation responsibility required for the circuit breaker, not only a single opening operation (hereinafter referred to as “single-O-operation”) but also an operation that opens immediately after closing (hereinafter referred to as “ -CO-operation ") and operation that performs" -CO-operation "after several hundreds of milliseconds (hereinafter referred to as" O-θ-CO operation ").

Among these, in the case of performing “-CO-operation”, the electrode is closed immediately after being opened, but gas is supplied only to the inside of the puffer chamber through the insulating nozzle during the closing operation. . In such a case, there is a possibility that the gas pressure inside the puffer chamber cannot be recovered to the rated gas pressure before the start of the “-CO-operation” O operation.

Further, when performing the “O-θ-CO operation”, there is a possibility that gas generated during the first O operation and remaining between the arc contacts may be taken into the puffer chamber by the CO operation. . Such a gas contains many electrons and ions, and is said to deteriorate the blocking performance and the insulating performance, and it is not preferable to take in a large amount in the puffer chamber.

Therefore, as a measure for preventing the recovery of the gas pressure and the intake of the high temperature gas, a spring type valve is generally attached to the puffer piston.

In the gas circuit breaker configured as described above, the gas pressure in the puffer chamber is remarkably increased when a large current is cut off, and the pressure acting on the puffer piston acts as a driving reaction force when the opening driving is performed. For this reason, especially in circuit breakers with a so-called self-efficiency type that uses a high operating force in the operating mechanism and obtains accumulated pressure in the puffer chamber using high-temperature gas from the arc, the puffer piston has a smaller diameter to reduce the driving reaction force. It is requested to do.

JP 2008-123762 A

The problem to be solved by the present invention is to provide a circuit breaker that realizes a valve structure that reduces the size of the puffer piston and that has a sufficient breaking performance even with a small driving force.

In the gas circuit breaker according to the embodiment, a movable arc contact and a fixed arc contact that can be brought into and out of contact with the movable arc contact are disposed opposite to each other in a sealed container filled with an arc extinguishing gas. The hollow operating rod is driven in the axial direction, and the movable arc contact is connected to the end portion toward the fixed arc contact. A puffer cylinder is formed coaxially with the operation rod, and the puffer cylinder is connected to the operation rod.

A puffer piston is inserted into the puffer cylinder to form a puffer chamber. The puffer piston has a compression plate provided with a plurality of communication holes in the circumferential direction communicating with the inside and outside of the puffer chamber, and a protruding portion that protrudes toward the puffer chamber on the inner peripheral portion of the compression plate. A valve plate is attached to the surface of the compression plate on the puffer chamber side so as to close the communication hole. This valve plate is movable by the pressure change of the puffer chamber.

A spring receiver is disposed on the protruding portion of the compression plate. A conical coil spring having an inner diameter on the small diameter side larger than the outer diameter of the protruding portion of the compression plate is disposed between the spring receiver and the valve plate.

A nozzle is connected to an end of the puffer cylinder so as to surround the movable arc contact.

Sectional drawing of the gas circuit breaker of 1st Embodiment. Sectional drawing which shows the state which the valve closed in the valve structure of the gas circuit breaker of 1st Embodiment. Sectional drawing which shows the state which the valve opened in the valve structure of the gas circuit breaker of 1st Embodiment. Sectional drawing which shows the case where the coil spring with a small wire diameter is used in the valve structure of the gas circuit breaker of 1st Embodiment. Sectional drawing which shows the state which the valve closed in the valve structure of the gas circuit breaker of 2nd Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view of the gas circuit breaker according to the first embodiment.

As shown in FIG. 1, a hermetic container (not shown) filled with an arc extinguishing gas 1 is fixed at a fixed position with respect to the hermetic container, a movable portion 2 that operates in an axial direction with respect to the hermetic container. The fixed portions 3 are arranged to face each other. The positional relationship of the movable part 2 will be described by defining the direction on the fixed part 3 side as the front and the opposite direction as the rear.

The movable part 2 includes a movable arc contact 4, an insulating nozzle 5, a movable energizing contact 6, an operating rod 7, a puffer cylinder 8, a puffer piston 9, a valve plate 10, a spring receiver 11, and a coil spring 12. The spring receiver 11 has a retaining ring 13 and a spring receiver 14.

The fixed portion 3 includes a fixed arc contact 15 and a fixed energization contact 16.

With respect to the movable portion 2, the movable arc contact 4 is connected to the front end of the hollow operation rod 7 toward the fixed arc contact 15. The operating rod 7 is connected to an operating mechanism (not shown) via an insulating rod (not shown), and is configured to reciprocate in the axial direction.

The puffer cylinder 8 is configured coaxially with the operation rod 7 and is connected to the operation rod 7 at the front end portion and is driven integrally.

A puffer piston 9 is slidably inserted into the puffer cylinder 8 to form a puffer chamber 17. An insulating nozzle 5 and a movable energizing contact 6 are connected to a surface perpendicular to the central axis on the front side of the puffer cylinder 8 (hereinafter referred to as the end of the cylinder). The insulating nozzle 5 is disposed so as to surround the movable arc contact 4, and the movable energizing contact 6 is disposed around the insulating nozzle 5.

The puffer piston 9 is fixed at a fixed position with respect to the sealed container by a piston support (not shown).

On the other hand, with respect to the fixed portion 3, the fixed arc contact 15 is disposed opposite to the movable arc contact 4 so as to be able to contact and separate, and a fixed energizing contact 16 is disposed around the fixed arc contact 15.

Next, the valve structure in the gas circuit breaker according to the first embodiment will be described with reference to FIGS. 2 is a cross-sectional view showing a closed state of the valve in the valve structure of the gas circuit breaker according to the first embodiment. FIG. 3 is a view showing a state in which the valve is opened in the valve structure of the gas circuit breaker according to the first embodiment. It is sectional drawing shown.

As shown in FIGS. 2 and 3, the disk-like compression plate 18 of the puffer piston 9 is provided with a plurality of communication holes 19 in the circumferential direction for communicating the inside and outside of the puffer chamber 17. On the side, a disc-shaped valve plate 10 capable of closing the communication hole 19 is disposed.

Further, the inner peripheral portion of the compression plate 18 protrudes toward the puffer chamber 17, and the retaining ring 13 is fixed to a groove provided in the protruding portion. A spring receiving portion 14 is disposed between the retaining ring 13 and the valve plate 10, and a truncated conical coil spring 12 is disposed between the spring receiving portion 11 and the valve plate 10. The valve plate 10, the coil spring 12, the retaining ring 13, and the spring receiving portion 14 are arranged coaxially with the operation rod 7. The valve plate 10 is held by a coil spring 12, and examples of the material of the coil spring 12 include stainless steel wire and piano wire.

In addition, the inner diameter of the wire closest to the spring receiving portion 14 of the coil spring 12 (hereinafter referred to as the inner diameter on the small diameter side) is larger than the outer diameter of the protruding portion of the compression plate 18. The diameter is larger than the outer diameter of the retaining ring 13.

In the gas circuit breaker of the first embodiment configured as described above, the movable portion 2 moves backward except for the puffer piston 9 during the opening operation. In the middle of the interruption process as shown in FIG. 1, the movable arc contact 4 and the fixed arc contact 15 are separated, and an arc 20 is generated between the movable arc contact 4 and the fixed arc contact 15. Since this arc 20 is very high temperature, high-temperature gas is generated from the arc 20 and the heated arc extinguishing gas 1 is also high temperature.

Since the high-temperature gas generated by the arc 20 in this way flows into the puffer chamber 17 through the insulating nozzle 5, the gas pressure in the puffer chamber 17 is increased. Therefore, as shown in FIG. 2, in addition to the reaction force of the coil spring 12, the pressure in the puffer chamber 17 is applied to the valve plate 10 in the direction of the arrow X in FIG. For this reason, the valve plate 10 is in close contact with the compression plate 18 of the puffer piston 9, and the air tightness inside the puffer chamber 17 is maintained.

Furthermore, since the volume of the puffer chamber 17 is reduced by the movement of the movable portion 2, the gas pressure in the puffer chamber 17 is also increased by this. Generally, the cutoff performance tends to increase as the gas pressure in the puffer chamber 17 increases.

Thereafter, the arc 20 becomes smaller toward the current zero point in the latter half of the shut-off process, and the arc extinguishing gas 1 that has become a high pressure is strongly blown from the puffer chamber 17 through the insulating nozzle 5 to the arc 20 to reach the arc extinction. The current interruption is completed.

Next, the closing operation will be described. During the closing operation, the movable portion 2 moves forward except for the puffer piston 9. Therefore, as the volume of the puffer chamber 17 increases, the pressure in the puffer chamber 17 decreases. Then, as shown in FIG. 3, a differential pressure in the direction of arrow Y in FIG. 3 is generated in the communication hole 19 in the compression plate 18 of the puffer piston 9, and a force in the compression direction is applied to the coil spring 12. When the force due to the differential pressure becomes larger than the force of the coil spring 12, the valve plate 10 moves in the direction of the arrow Y in FIG. 3, the communication hole 19 is opened away from the compression plate 18 of the puffer piston 9, and the gas flow path 21 is opened. It is formed.

For this reason, in addition to the arc-extinguishing gas 1 supplied through the insulating nozzle 5, the room temperature arc-extinguishing gas 1 in a sealed container (not shown) is supplied into the puffer chamber 17 through the gas flow path 21.

Finally, when the closing operation is completed and the pressure in the puffer chamber 17 is restored to the initial state, the valve plate 10 returns to the original position again.

In this way, in addition to the supply from the insulating nozzle 5, the normal temperature arc extinguishing gas 1 in the sealed container is supplied through the communication hole 19, so that the O operation starts even when performing the “−CO-operation”. By this time, the gas pressure inside the puffer chamber 17 can be recovered to the rated gas pressure.

Further, in the case of performing the “O-θ-CO operation”, the gas generated during the first O operation and remaining between the arc contacts 4 and 15 is taken into the puffer chamber 17 more than necessary. Can be prevented.

In the gas circuit breaker of the first embodiment, the valve plate 10 is held by one large-diameter coil spring 12 instead of providing a plurality of small-diameter coil springs. Therefore, the valve plate 10 can be configured if the outer diameter of the coil spring 12 is larger than the outer diameter of the wire closest to the valve plate 10 (hereinafter referred to as the outer diameter on the large diameter side), and the puffer piston 9 is reduced in diameter. be able to. Therefore, the driving reaction force due to the pressure increase of the puffer chamber 17 at the time of current interruption is reduced, and the current interruption performance can be satisfied with a smaller operation driving force.

In addition, by using one large-diameter coil spring 12, it is possible to reduce the number of parts of the coil spring and spring receiver for holding the valve plate 10 and to reduce the cost.

In the gas circuit breaker of the first embodiment, when the pressure change in the puffer chamber 17 during the closing operation is small, a coil spring 22 having a small wire diameter can be used as shown in FIG. is there. Since the retaining ring 13 can play the role of the spring receiving portion 14 due to the small wire diameter of the coil spring 22, it can further contribute to the reduction of the number of parts.

(Second Embodiment)
A second embodiment will be described with reference to FIG. In addition, the same part as each part of the gas circuit breaker of 1st Embodiment shown in FIG. 1 thru | or FIG. 4 is shown with the same code | symbol. FIG. 5 is a cross-sectional view showing a state in which the valve is closed in the valve structure of the gas circuit breaker according to the second embodiment.

In the second embodiment, in the spring receiver 24 having the spring receiver 23 and the retaining ring 13, the outer diameter of the spring receiver 23 is larger than the outer diameter of the coil spring 12 on the larger diameter side, as shown in FIG. 5. The point which provided the projection part which protruded in the coil spring 12 side in the outer peripheral part differs from 1st Embodiment.

According to the second embodiment, basically the same effects as those of the first embodiment can be obtained. In addition to this, in the second embodiment, when the coil spring 12 is compressed, it is housed inside the spring receiving portion 23. Moreover, the movable range of the valve plate 10 is limited by the protruding portion formed in the spring receiving portion 23, and the coil spring 12 can be prevented from being compressed more than necessary. Therefore, damage to the coil spring 12 is suppressed, and mechanical durability is improved.

According to at least one embodiment described above, it is possible to provide a circuit breaker that realizes a valve structure that reduces the size of the puffer piston and that has sufficient breaking performance even with a small driving force.

In the above embodiment, the spring receivers 11 and 24 are described separately for the spring receivers 14 and 23 and the retaining ring 13, but they are not necessarily separated, for example, when they are integrally formed.

Although several embodiments of the present invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof in the same manner as included in the scope and gist of the invention.

DESCRIPTION OF SYMBOLS 1 ... Arc extinguishing gas 2 ... Movable part 3 ... Fixed part 4 ... Movable arc contact 5 ... Insulating nozzle 6 ... Movable energizing contact 7 ... Operation rod 8 ... Puffer cylinder 9 ... Puffer piston 10 ... Valve plates 11, 24 ... Spring receivers 12, 22 ... Coil spring 13 ... Retaining ring 14, 23 ... Spring receiver 15 ... Fixed arc contact 16 ... Fixed energizing contact 17 ... Puffer chamber 18 ... Compression plate 19 ... Communication hole 20 ... Arc 21 ... Gas flow Road

Claims (2)

A sealed container filled with arc-extinguishing gas;
A movable arc contact disposed in the sealed container;
A fixed arc contact that is disposed opposite the movable arc contact and is capable of contacting and leaving the movable arc contact;
A hollow operating rod that is connected to an end of the movable arc contact toward the fixed arc contact, and is driven in an axial direction;
A puffer cylinder configured coaxially with the operation rod and connected to the operation rod;
A compression plate that is inserted into the puffer cylinder, forms a puffer chamber together with the puffer cylinder, and has a plurality of communication holes in the circumferential direction communicating with the inside and the outside of the puffer chamber, and the puffer on the inner peripheral portion of the compression plate A puffer piston having a protruding portion protruding toward the chamber side;
A valve plate attached to a surface of the compression plate on the puffer chamber side so as to close the communication hole, and movable by a pressure change in the puffer chamber;
A spring receiver disposed on the protruding portion of the compression plate;
A coil spring of a truncated cone disposed between the spring receiver and the valve plate, wherein the inner diameter of the small diameter side is larger than the outer diameter of the protruding portion of the compression plate;
A gas circuit breaker comprising: a nozzle connected to an end of the puffer cylinder and arranged to surround the movable arc contact. The outer diameter of the spring receiver is larger than the outer diameter on the large diameter side of the coil spring, and an outer peripheral portion of the spring receiver has a protruding portion on the coil spring side so that it is housed when the coil spring is compressed. The gas circuit breaker according to claim 1.

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