JPH07161269A - Puffer type gas circuit breaker - Google Patents

Abstract

PURPOSE:To improve the reliability of a circuit breaker by providing a vent hole, which communicates with the outside of a puffer cylinder from a main puffer chamber, in a fixed piston, so as to eliminate necessity for a check valve. CONSTITUTION:A vent hole 8A is provided in a fixed piston 8 in a gas circuit breaker principal part, and also omitting a check valve conventionally mounted in a through hole 6A. Since a puffer cylinder 5 is driven in an X direction at a high speed when opened a contact, a pressure is generated in a main puffer chamber 9 to rise to the pressure necessary for extinguishing an arc. After high pressure gas is blown as shown by a gas flow 14 from a blow hole 6A, expansion gas generated by an arc 15 is returned back into the main puffer chamber 9. Since this expansion gas partly leaks out from the vent hole 8A, an internal pressure in the main puffer chamber 9 is suppressed to a certain fixed pressure or less, to reduce a burden of a drive rod 12 at the time of opening the contact. Accordingly, necessity for the check valve is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a puffer type gas circuit breaker used as a large capacity power circuit breaker, and more particularly to a structure of an arc extinguishing chamber thereof.

[0002]

2. Description of the Related Art A puffer type gas circuit breaker is for compressing arc extinguishing gas and blowing the compressed gas to the open gap of the interrupting portion to extinguish the arc and interrupt a large current.
SF ₆ gas is excellent as a gas for extinguishing arcs, and is used even for circuit breakers of ultra-high pressure and large capacity.

FIG. 4 is a sectional view showing the structure of a conventional puffer type gas circuit breaker. A high pressure SF ₆ gas is enclosed as an arc extinguishing gas in a cylindrical tank 1, and a fixed contactor 3 and a movable contactor 4 serving as contacts are housed therein. The fixed contactor 3 and the movable contactor 4 are provided with current-carrying conductors 3A and 4A, respectively.
Is connected to other circuit equipment (not shown).
The fixed contactor 3 is fixedly supported by the tank 1 via the insulator 2, while the movable contactor 4 is directly supported by the puffer cylinder 5 to form an open gap portion 19.

The puffer cylinder 5 shown in FIG. 4 is an insulating nozzle 1.
A cylindrical drive rod 12 is provided at the center of the shaft while supporting 0A and 10B. Also, the puffer cylinder 5
A fixed piston 8 that forms a puffer chamber is fitted between the drive rod 12 and the drive rod 12, and a partition 16 that divides the puffer chamber into an auxiliary puffer chamber 6 and a main puffer chamber 9 is fixed. Opening gap 1 of auxiliary puffer chamber 6
The spray hole 6A penetrates the 9 side and the partition 16
A through hole 16A is provided in the. This through hole 16A
A check valve 17 that allows gas to pass only from the main puffer chamber 9 to the auxiliary puffer chamber 6 is attached to this. The fixed piston 8 is fixedly supported by the tank 1 via the insulating porcelain pipe 7.

FIG. 4 shows a state where the current is being cut off. The drive rod 12 is connected to an operating mechanism (not shown) via the insulating rod 7. When the insulating rod 7 is driven in the X direction, the drive rod 12 and the puffer cylinder 5, the movable contactor 4, and the insulating nozzles 10A and 10B, which are an integral movable part, move in the X direction, and the inside of the main puffer chamber 9 is moved. Gas is compressed. In a state where the fixed contactor 3 does not escape from the throat portion 10 of the insulating nozzle 10A, as shown in FIG. 4, the compressed gas from the main puffer chamber 9 becomes the gas flow 14A through the auxiliary puffer chamber 6 and the insulating nozzles 10A and 10B. Flowing through the gap. The gas flow 14A cools the arc 15 generated in the opening gap portion 19, and the arc 15
The gas heated by the gas is discharged into the free space 11 outside the puffer cylinder 5 as gas flows 14B and 14C in the exhaust passage 12A in the drive rod 12. As the breaking current increases, the arc 15 increases and the exhaust passage 12 increases.
Attempt to block the inlet 12B of A. The gas in the separation gap 19 expanded by the arc heat becomes a flow in the direction opposite to the gas flow 14A and enters the auxiliary puffer chamber 6 through the spray hole 6A. At that time, since the check valve 16A is provided, gas does not enter the main puffer chamber 9. Since the gas pressure in the auxiliary puffer chamber 6 rises due to the arc heat as the breaking current increases, a large amount of gas stored in the auxiliary puffer chamber 6 is blown out when the fixed contact 3 escapes from the throat portion 10 of the insulating nozzle 10A. It flows out through 6A and blows out the arc 15.

Such an arc extinguishing method, that is, a method of extinguishing the inlet 12B of the exhaust passage 12A with the arc 15 so that the pressure rise in the auxiliary puffer chamber 6 is increased to extinguish the arc at the initial stage of the current interruption is described by puff ". It is called a puffer shape derived from the meaning of "blowing out", and the fixed contactor 3 has an insulating nozzle 10A.
It is used as a large current circuit breaker because a large amount of gas can be blown to the arc 15 when the throat section 10 is escaped.

[0007]

However, the conventional device as described above has a problem that the check valve is easily damaged. That is, the check valve plays a role of preventing the internal pressure of the main puffer chamber from rising due to the inflow of the expansion gas, and reducing the load on the drive rod. But,
Since the check valve is directly exposed to arc heat, malfunction of the valve function is likely to occur, and the check valve may be melted and damaged when the circuit breaker is repeatedly opened and closed. Moreover, the structure for mounting the check valve is complicated, and the manufacturing cost is high.

The purpose of this puffer cylinder is to eliminate the use of check valves and to provide a more reliable and inexpensive device.

[0009]

In order to achieve the above object, according to the present invention, a fixed contact and a movable contact that can be brought into contact with and separated from the fixed contact are provided in a tank filled with an arc extinguishing gas. A puffer cylinder that interlocks with this movable contactor, a drive rod that is arranged at the axial center of this puffer cylinder and that drives the movable contactor and the puffer cylinder in the axial direction, and a puffer chamber between this drive rod and the puffer cylinder. Forming a gap between the fixed contact and the movable contactor through a spray hole that surrounds the movable contactor and compresses the gas compressed in the puffer chamber on the side of the puffer cylinder opposite to the fixed piston. And an insulating nozzle that guides the puffer chamber to the inside of the puffer cylinder. The partition is provided in the puffer cylinder to partition the puffer chamber from the spray hole side into two chambers, an auxiliary puffer chamber and a main puffer chamber. In those through holes for communicating the auxiliary puffer chamber and the main puffer chamber the partition is provided, it may be assumed that the gas vent hole is provided leading from the main puffer chamber to the fixed piston of the puffer cylinder to the outside.

Further, in such a structure, it is preferable that the cross-sectional area in the radial direction of the main puffer chamber is smaller than that of the auxiliary puffer chamber. Furthermore, in a tank filled with an arc-extinguishing gas, a fixed contact, a movable contact that can be brought into contact with and separated from the fixed contact, a puffer cylinder that interlocks with the movable contact, and a shaft center portion inside the puffer cylinder. A drive rod arranged to drive the movable contactor and the puffer cylinder in the axial direction, a fixed piston that forms a puffer chamber between the drive rod and the puffer cylinder, and a gas that surrounds the movable contact and is compressed in the puffer chamber. Of the puffer cylinder from the blowing hole to the opening gap between the fixed contact and the movable contact from the blowing hole, and the puffer chamber from the blowing hole side to the auxiliary puffer. A partition that divides the chamber and the main puffer chamber in series is provided in the puffer cylinder, and a penetrating that connects the auxiliary puffer chamber and the main puffer chamber to this partition. In what is provided, a partition is provided with a through hole in the drive rod side, or equal to that formed by inclined obliquely to the fixed piston side toward the outer diameter side.

[0011]

According to the structure of the present invention, the fixed piston is provided with the gas vent hole communicating from the main puffer chamber to the outside of the puffer cylinder. As a result, even if the pressure in the auxiliary puffer chamber rises due to the expansion gas, and the expansion gas enters the main puffer chamber, the gas leaks from the gas vent hole to the outside of the puffer cylinder, so the pressure in the main puffer chamber does not rise extremely. . That is, the gas vent hole plays a role of replacing the check valve of the conventional device, and suppresses the pressure increase in the main puffer chamber. Therefore, according to this configuration, since it is only necessary to drill the fixed piston, it is cheaper and more reliable than the check valve.

In this structure, the radial cross-sectional area of the main puffer chamber is made smaller than that of the auxiliary puffer chamber. The internal pressure of the main puffer chamber acts as an axial reaction force that pushes back to the fixed contactor side of the puffer cylinder. Since the axial reaction force of the puffer cylinder is reduced by reducing the radial cross-sectional area of the main puffer chamber, the operating force of the drive rod can also be reduced.

Further, according to the structure of the present invention, the partition is provided with the through hole on the drive rod side and is inclined. As a result, the pressure in the auxiliary puffer chamber rises due to the expansion gas,
Even if the gas tries to enter the main puffer chamber, separation of the gas flow occurs at the through hole because the partition is oblique. That is, some gas enters the main puffer chamber through the through hole, but most of the gas flows to the outer diameter side along the surface of the partition on the auxiliary puffer chamber side. for that reason,
Also in this configuration, the check valve is unnecessary because the pressure increase in the main puffer chamber is suppressed.

[0014]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is a cross-sectional view showing a main configuration of a puffer type gas circuit breaker according to an embodiment of the present invention. The fixed piston 8 is provided with a gas vent hole 8A, and the check valve conventionally attached to the through hole 16A is omitted. Figure 4 otherwise
The same reference numerals are used for the same parts and the detailed description thereof will be omitted.

In FIG. 1, the puffer cylinder 5 is driven at high speed in the X direction when the contacts are opened even if the fixed piston 8 is provided with the gas vent hole 8A, so that the main puffer chamber 9 is opened.
Rises to the pressure needed to extinguish the arc. After the high pressure gas is blown from the blowing hole 6A like the gas flow 14A, the arc 1
The expansion gas generated by 5 returns to the inside of the main puffer chamber 9. However, a part of this expanded gas is discharged from the gas vent hole 8A.
Since it leaks from the inside, the internal pressure of the main puffer chamber 9 is suppressed below a certain constant pressure, and the load on the drive rod 12 at the time of contact opening is reduced. Therefore, the check valve becomes unnecessary.

In FIG. 1, there is only one gas vent hole 8A. When the fixed piston 8 has a large supporting portion and a gas vent hole having an excessively large diameter cannot be formed, a gas vent hole having a predetermined opening area can be provided by forming a plurality of small holes. FIG. 2 is a cross-sectional view showing the configuration of the essential parts of a puffer type gas circuit breaker according to a different embodiment of the present invention. Main puffer chamber 9 of puffer cylinder 50
The thickness 90T on the 0 side is made thicker so that the radial width 90D of the main puffer chamber 90 is smaller than the radial width 6D of the auxiliary puffer chamber 6. Others are the same as the configuration of FIG.

In FIG. 2, the internal pressure of the main puffer chamber 90 acts as a reaction force Y that pushes the puffer cylinder 50 back toward the fixed contactor 3. Since the radial cross-sectional area of the main puffer chamber 90 (the area of the partition 16 on the main puffer chamber 90 side) is smaller than that on the auxiliary puffer chamber 6 side, the reaction force Y is also small.
Therefore, the load on the drive rod 12 when the contacts are opened is reduced as shown in FIG.
It is further reduced as compared with the case of the above configuration.

In FIG. 2, the outer diameter of the drive rod 12 is partially increased to make the main puffer chamber 9 larger.
The radial width 90D of 0 may be reduced. FIG. 3 is a cross-sectional view showing a main part configuration of a puffer type gas circuit breaker according to a further different embodiment of the present invention. The partition 20 provided on the puffer cylinder 51 is provided with the through hole 20A on the drive rod 12 side, and is inclined in the X direction toward the outer diameter side. Other than that, the configuration is the same as that of FIG. 1 except that the gas vent hole provided in the fixed piston 8 is omitted.

In FIG. 3, the expansion gas in the auxiliary puffer chamber 61 becomes a gas flow 14E and tries to enter the main puffer chamber 91 side from the through hole 20A, but the gas flow 14E is separated, and some gas is mainly discharged. Although entering the puffer chamber 91, most of the gas flows to the outer diameter side along the surface of the partition 20 on the side of the auxiliary puffer chamber 61. Thus, gas flow 1
The peeling of 4E occurs because the partition 20 is formed obliquely. When the contact opening speed is slow, the separated gas circulates inside the auxiliary puffer chamber 61 and tries to exit from the through hole 20A again, but the opening speed is high,
The expanded gas is guided to the opening gap 19 from the spray hole 6A before returning to the through hole 20A again. Therefore, the rise in the internal pressure of the main puffer chamber 91 is suppressed, so that the check valve and the gas vent hole on the fixed piston side are unnecessary.

[0020]

As described above, the present invention eliminates the need for the check valve by providing the fixed piston with the gas vent hole.
Improved reliability and cost reduction have eliminated the problem of check valve damage. Further, in such a configuration, by making the cross-sectional area of the main puffer chamber smaller than that of the auxiliary puffer chamber, the operating force of the drive rod is reduced and the drive operating mechanism can be downsized.

Further, even if the partition is formed obliquely in the puffer chamber, the check valve becomes unnecessary and the reliability is improved and the cost is reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the configuration of a main part of a puffer type gas circuit breaker according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main configuration of a puffer type gas circuit breaker according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a main part configuration of a puffer type gas circuit breaker according to still another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing the configuration of a conventional puffer type gas circuit breaker.

[Explanation of symbols]

3: fixed contactor, 4: movable contactor, 5, 50, 51: puffer cylinder, 6A: spray hole, 9, 90, 91: main puffer chamber, 7: insulator tube, 8: fixed piston, 19:
Separation gap part, 10: throat part, 10A, 10B, 10
C: Insulation nozzle, 12: Drive rod, 12A: Exhaust passage, 13: Insulation rod, 14A, 11B, 14E: Gas flow, 15: Arc, 6,61: Auxiliary puffer chamber, 16
A, 20A: Through hole, 8A: Gas vent hole, 16, 20:
Partition, 11: Free space

Claims (3)

[Claims] 1. A fixed contact, a movable contact capable of coming into contact with and separating from the fixed contact, a puffer cylinder interlocking with the movable contact, and a shaft center in the puffer cylinder in a tank filled with an arc-extinguishing gas. Drive rod that is arranged in the section to drive the movable contactor and the puffer cylinder in the axial direction, a fixed piston that forms a puffer chamber between the drive rod and the puffer cylinder, and a movable rod that surrounds the movable contactor and is compressed in the puffer chamber. It is composed of an insulating nozzle that guides the generated gas from the spray hole provided on the side opposite to the fixed piston of the puffer cylinder to the separation gap between the fixed contact and the movable contact, and the puffer chamber from the spray hole side. A partition that divides the auxiliary puffer chamber and the main puffer chamber in series is provided inside the puffer cylinder, and the partition that allows the auxiliary puffer chamber and the main puffer chamber to communicate with each other. In what is provided, puffer type gas circuit breaker, wherein a gas vent hole is provided leading from the main puffer chamber to the fixed piston of the puffer cylinder to the outside. 2. A puffer-type circuit breaker according to claim 1, wherein a radial cross-sectional area of the main puffer chamber is smaller than that of the auxiliary puffer chamber. 3. A fixed contact, a movable contact capable of coming into contact with and separating from the fixed contact, a puffer cylinder interlocking with the movable contact, and a shaft center in the puffer cylinder in a tank filled with an arc-extinguishing gas. Drive rod that is arranged in the section to drive the movable contactor and the puffer cylinder in the axial direction, a fixed piston that forms a puffer chamber between the drive rod and the puffer cylinder, and a movable rod that surrounds the movable contactor and is compressed in the puffer chamber. It is composed of an insulating nozzle that guides the generated gas from the spray hole provided on the side opposite to the fixed piston of the puffer cylinder to the separation gap between the fixed contact and the movable contact, and the puffer chamber from the spray hole side. A partition that divides the auxiliary puffer chamber and the main puffer chamber in series is provided inside the puffer cylinder, and the partition that allows the auxiliary puffer chamber and the main puffer chamber to communicate with each other. In what is provided, a partition is provided with a through hole in the drive rod side, puffer type gas circuit breaker characterized by comprising inclined obliquely to the fixed piston side toward the outer diameter side.