WO2019092866A1

WO2019092866A1 - Gas circuit breaker

Info

Publication number: WO2019092866A1
Application number: PCT/JP2017/040662
Authority: WO
Inventors: 内井　敏之; 吉野　智之; 加藤　紀光; 田中　勉
Original assignee: 株式会社東芝; 東芝エネルギーシステムズ株式会社
Priority date: 2017-11-10
Filing date: 2017-11-10
Publication date: 2019-05-16
Also published as: JP6773918B2; JPWO2019092866A1

Abstract

Provided is a gas circuit breaker with which it is possible to reduce a decrease in the flow rate of arc-extinguishing gas sprayed on an arc. A gas circuit breaker 1 having a pressure accumulation chamber 38 that communicates with a compression chamber 36 via a through-hole 42b, is formed of a trigger electrode 31 and a second arc contactor 41, and stores arc-extinguishing gas that is increased in pressure in the compression chamber 36, the gas circuit breaker 1 being such that: in the first half during current breaking, the pressure accumulation chamber 38 is sealed by the trigger electrode 31 and the second arc contactor 41; and in the latter half during current breaking, the pressure accumulation chamber 38 is opened by the trigger electrode 31 and the second arc contactor 41 moving apart, arc-extinguishing gas is sprayed from an opening of the second arc contactor 41, and the arc between a first arc contactor 21 and the second arc contactor 41 is extinguished; wherein the through-hole 42b via which the pressure accumulation chamber 38 and the compression chamber 36 communicate has a check valve 42e for preventing the inflow of arc-extinguishing gas from the pressure accumulation chamber 38 to the compression chamber 36.

Description

Gas circuit breaker

The present embodiment relates to a gas circuit breaker that shuts off current in a power system.

Gas circuit breakers are used to interrupt the current flowing in the power supply lines of the power system. The gas circuit breaker is disposed on the power supply line to interrupt the current flowing when disconnecting the system where the accident occurred in the event of a system accident.

The puffer type gas circuit breaker is widely used as the above-mentioned gas circuit breaker. The puffer type gas circuit breaker has a pair of electrodes disposed opposite to each other in a closed vessel filled with an arc-extinguishing gas. The pair of electrodes are driven by a driving device disposed outside the gas circuit breaker to open and close.

When the gas circuit breaker is opened, the pair of electrodes are driven by a driving device disposed outside the gas circuit breaker and mechanically disconnected. However, since the voltage in the power system is a high voltage, the arc current continues to flow even after the pair of electrodes is mechanically disconnected. The puffer-type gas circuit breaker interrupts this arc current by blowing an arc extinguishing gas in the closed vessel to the arc and extinguishing the arc.

JP, 2014-72032, A JP, 2015-79635, A JP, 2015-185381, A JP, 2015-185465, A

In the gas circuit breaker as described above, an arc is generated between the electrodes which are separated at the time of current interruption. The gas circuit breaker as described above extinguishes the arc by pressurizing the arc-extinguishing gas and ejecting the pressurized arc-extinguishing gas to the arc. Therefore, it is not desirable that the arc-extinguishing gas pressurized before the discharge to the arc leak and the pressure be reduced. The pressure drop of the pressurized arc-extinguishing gas is to reduce the flow rate of the arc-extinguishing gas and make it difficult to extinguish the arc reliably.

The arc generated between the electrodes becomes high temperature. For this reason, the arc-extinguishing gas blown to the arc also becomes high temperature and expands, and also becomes higher in pressure than the arc-extinguishing gas pressurized by means of pressure increase. The arc-extinguishing gas expanded to a high pressure flows back to the means for pressurizing the arc-extinguishing gas through a path for causing the arc-extinguishing gas to be ejected to the arc.

As a result, there is a problem that a part of the arc-extinguishing gas pressurized by the means for boosting is not sprayed to the arc, and the flow rate of the arc-extinguishing gas ejected to the arc decreases.

An object of the present embodiment is to provide a gas circuit breaker capable of reducing a decrease in the flow rate of the arc-extinguishing gas ejected to the arc.

The gas circuit breaker of this embodiment is characterized by having the following configuration.
(1) A first arc contact electrically connected to a first lead conductor connected to the power system.
(2) A second arc contact electrically connected to the second lead conductor.
(3) Movable between the first arc contact and the second arc contact, and occurs between the first arc contact and the first half of the current interruption when the current is interrupted. The arc is ignited, and a trigger electrode which causes the arc to ignite the second arc contact as it moves in the second half of the current interruption.
(4) A compression chamber for pressurizing the arc-extinguishing gas.
(5) A pressure accumulation chamber, which communicates with the compression chamber through a through hole, is formed by the trigger electrode and the second arc contact, and stores an arc-extinguishing gas pressurized in the compression chamber.
(6) In the first half of the current interruption, the pressure accumulation chamber is sealed by the trigger electrode and the second arc contact. In the second half of the current interruption, the pressure accumulation chamber includes the trigger electrode and the second The two arc contacts are released by being separated and an arc-extinguishing gas is ejected from the opening of the second arc contact, and between the first arc contact and the second arc contact The arc of the arc is extinguished.
(7) The through hole communicating the pressure accumulation chamber with the compression chamber has a check valve for preventing the flow of arc-extinguishing gas from the pressure accumulation chamber into the compression chamber.

The figure which shows the closed state of the gas circuit breaker concerning 1st Embodiment. The figure which shows the state of the first half at the time of the electric current interruption of the gas circuit breaker concerning 1st Embodiment. The figure which shows the state of the second half at the time of the electric current interruption of the gas circuit breaker concerning 1st Embodiment. Enlarged view of the check valve of the gas circuit breaker according to the first embodiment

First Embodiment
[1-1. Outline configuration]
Hereinafter, the entire configuration of the gas circuit breaker 1 of the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 shows an internal structure when the gas circuit breaker 1 is in a closed state.

The gas circuit breaker 1 includes a first fixed contact portion 2 (hereinafter collectively referred to as "fixed contact portion 2"), a movable contact portion 3 and a second fixed contact portion 4 (hereinafter referred to as "fixed contact Section 4 ") and a closed container 8. The lead-out conductor 7 a is connected to the fixed contact portion 2 and the lead-out conductor 7 b is connected to the fixed contact portion 4 via the sealed container 8. The lead conductors 7a, 7b are connected to the power system. The gas circuit breaker 1 is installed in a power supply facility such as a substation.

The fixed contact portion 2 and the fixed contact portion 4 are cylindrical members made of conductive metal. The movable contact portion 3 is a cylindrical member made of conductive metal and disposed in close contact with the fixed contact portion 2 and the inner diameter of the fixed contact portion 4 so as to be slidable. The fixed contact portion 2 and the fixed contact portion 4 are fixed in an airtight container 8 with an insulator (not shown) spaced apart.

The movable contact portion 3 is a cylindrical member made of a conductive metal. The movable contact portion 3 is driven by a drive device 9 disposed outside the gas circuit breaker 1, and moves between the fixed contact portion 2 and the fixed contact portion 4 to thereby move the fixed contact portion 2 and the fixed contact portion 2. The fixed contact portion 4 is electrically disconnected or made conductive. Thus, the lead conductors 7a and 7b are electrically disconnected or conducted.

Here, although the stationary contact portion 2 is described as being fixed and not moving for simplicity, the stationary contact portion 2 may be driven relative to the movable contact portion 3. Although the structure is complicated, it is because the insulation distance between the fixed contact portion 2 and the movable contact portion 3 can be rapidly increased in the open state.

When the gas circuit breaker 1 is in the open state, an arc is generated between the fixed contact 2 and the movable contact 3. The arc is extinguished by blowing an arc-extinguishing gas filled in the closed vessel 8 at a high pressure.

The closed container 8 is a cylindrical closed container made of metal, insulator or the like, and is filled with an arc-extinguishing gas. As the arc-extinguishing gas, sulfur hexafluoride gas (SF6 gas) excellent in arc-extinguishing performance and insulation performance is used. In the case of metal, the closed container 8 is connected to the ground potential. The pressure in the closed vessel 8 is a single pressure, for example, the full pressure of the arc-extinguishing gas, in any part during normal operation.

An arc extinguishing gas is an electrically insulating gas for extinguishing an arc. At present, SF6 gas is often used as an arc extinguishing gas. However, SF6 gas has a high global warming effect. Therefore, other gases may be used as arc extinguishing gas instead of SF6 gas. As an arc-extinguishing gas to be substituted for SF6 gas, it is desirable that the insulating property, arc cooling property (arc-extinguishing property), chemical stability, environmental compatibility, availability, cost and the like be excellent. According to the present embodiment shown in FIG. 1 to FIG. 3, since the blowing gas is pressurized by adiabatic compression, the arc-extinguishing gas to be substituted for SF6 has a specific heat which tends to increase in pressure with the same cylinder volume and compression rate It is desirable that the gas has a large ratio.

The driving device 9 is a device for driving the movable contact portion 3 when the gas circuit breaker 1 is opened and closed. The drive device 9 has a power source inside, and a spring, oil pressure, high pressure gas, electric motor or the like is applied as the power source. The movable contact portion 3 is moved between the fixed contact portion 2 and the fixed contact portion 4 by the driving device 9, and the fixed contact portion 2 and the fixed contact portion 4 are electrically disconnected or made conductive. Ru.

The drive device 9 operates based on a command signal transmitted from the outside when the gas circuit breaker 1 is opened and closed. The driving device 9 is required to stably store large driving energy, to have extremely quick response to a command signal, and to perform more reliable operation. The drive 9 need not be in an arc extinguishing gas.

When the circuit breaker 1 is in an open state, an arc-extinguishing gas pressurized in a compression chamber 36 described later passes through an accumulator chamber 38 described later, and an arc contact (fixed side) 21 and an arc contact (movable side) 41 It is desirable to hold the position of the piston 33 so that the piston 33 of the movable contact portion 3 does not reverse until the pressure in the compression chamber 36 is sufficiently reduced by being discharged into the arc space between them. The backward movement of the piston 33 enlarges the volume of the compression chamber 36, and the pressure in the compression chamber 36 and the pressure accumulation chamber 38 decreases. This is because it is not desirable that the spray pressure to the arc be reduced. In order to prevent this retrogression, the drive device 9 may be provided with a retrogression preventing structure.

The fixed contact portion 2 is a cylindrical member disposed in the closed container 8. The fixed contact portion 2 includes an arc contact (fixed side) 21, a fixed conductive contact 22, an insulating nozzle 23, and an exhaust cylinder 24. The arc contact (fixed side) 21 corresponds to the first arc contact in the claims. Details of these members will be described later. The lead conductor 7 a is connected to the fixed contact portion 2 via the sealed container 8. The fixed contact portion 2 is fixed to the closed container 8 and disposed. The fixed contact portion 2 is electrically connected to the fixed contact portion 4 via the movable contact portion 3 when the gas circuit breaker 1 is in a closed state, and conducts current between the lead-out conductors 7a and 7b. On the other hand, when the gas circuit breaker 1 is in the open state, the fixed contact 2 is electrically disconnected from the movable contact 3 and cuts off the current between the lead conductors 7a and 7b.

The fixed contact portion 4 is a cylindrical member disposed in the closed container 8. The fixed contact portion 4 has an arc contact (movable side) 41, a cylinder 42, and a support 43. The arc contact (movable side) 41 corresponds to a second arc contact in the claims. The arc contact (movable side) 41 itself does not move. Details of these members will be described later. The lead conductor 7 b is connected to the fixed contact portion 4 through the sealed container 8. The fixed contact portion 4 is fixed to the closed container 8 and disposed.

The fixed contact portion 4 is electrically connected to the fixed contact portion 2 via the movable contact portion 3 when the gas circuit breaker 1 is in a closed state, and conducts the current between the lead-out conductors 7a and 7b. On the other hand, since the fixed contact 2 and the movable contact 3 are electrically disconnected when the gas circuit breaker 1 is in the open state, the fixed contact 4 cuts off the current between the lead-out conductors 7a and 7b. .

The movable contact portion 3 is a cylindrical member disposed in the closed container 8. The movable contact portion 3 has a trigger electrode 31, a movable conductive contact 32, a piston 33, a piston support 33 a, and an insulating rod 37. Details of these members will be described later. The movable contact portion 3 is arranged to be capable of reciprocating movement between the fixed contact portion 2 and the fixed contact portion 4.

The movable contact portion 3 is mechanically connected to a driving device 9 disposed outside the gas circuit breaker 1. When the gas circuit breaker 1 is opened and closed, the movable contact portion 3 is driven by the drive device 9 and the current flowing to the lead-out conductors 7a and 7b is interrupted and conducted. The movable contact portion 3 electrically connects the fixed contact portion 2 and the fixed contact portion 4 when the gas circuit breaker 1 is closed, and conducts current between the lead-out conductors 7a and 7b. On the other hand, when the gas circuit breaker 1 is in the open state, the movable contact portion 3 is electrically disconnected from the fixed contact portion 2 and cuts off the current between the lead conductors 7a and 7b.

Further, the movable contact portion 3 compresses the arc-extinguishing gas accumulated in the cylinder 42 by the piston 33 and spouts it through the insulating nozzle 23 to generate between the fixed contact portion 2 and the movable contact portion 3 The arc current is cut off by extinguishing the arc.

The fixed contact portion 2, the movable contact portion 3, the fixed contact portion 4, and the closed container 8 are cylindrical members that draw concentric circles, have a common central axis, and are disposed on the same axis. In the following, when describing the positional relationship and direction of each member, the direction on the fixed contact portion 2 side is referred to as the open end direction, and the direction on the opposite fixed contact portion 4 side is referred to as the drive device direction.

[1-2. Detailed configuration]
(Fixed contact 2)
The fixed contact portion 2 includes an arc contact (fixed side) 21, a fixed conductive contact 22, an insulating nozzle 23, and an exhaust cylinder 24. The arc contact (fixed side) 21 corresponds to a first arc contact in the claims. Also in the text, the arc contact (fixed side) 21 may be referred to as a first arc contact.

(Fixed energizing contact 22)
The fixed conductive contact 22 is a ring-shaped electrode disposed on the outer peripheral end face of the fixed contact portion 2 in the driving device direction. The fixed conductive contact 22 is formed of a metal conductor formed in a ring shape that bulges to the inner diameter side by cutting or the like. The metal constituting the fixed current-carrying contact 22 is preferably aluminum from the viewpoints of electrical conductivity, lightness, strength, and processability, but it may be copper, for example.

The fixed conductive contact 22 has an inner diameter that can slide with the outer diameter of the movable conductive contact 32 of the movable contact portion 3 with a fixed clearance. The fixed conductive contact 22 is disposed at an end of the exhaust cylinder 24 made of a cylindrical conductive metal in the direction of the driving device. The lead-out conductor 7 a is connected to the exhaust cylinder 24 via the sealed container 8. The exhaust cylinder 24 is fixed to the sealed container 8 via an insulating member.

When the gas circuit breaker 1 is in the closed state, the movable energizing contact 32 of the movable contact portion 3 is inserted into the fixed energizing contact 22. As a result, the fixed conductive contact 22 comes in contact with the movable conductive contact 32, and electrically connects the fixed contact portion 2 and the movable contact portion 3. The fixed conducting contact 22 passes a rated current when conducting.

On the other hand, when the circuit breaker 1 is in the open state, the fixed conductive contact 22 physically separates from the movable conductive contact 32 of the movable contact portion 3 and electrically connects the fixed contact portion 2 and the movable contact portion 3 Cut off.

(Arc contact (fixed side) 21)
The arc contact (fixed side) 21 is a cylindrical electrode disposed along the central axis of the cylinder of the fixed contact 2 and at the end of the fixed contact 2 in the direction of the driving device. The arc contact (fixed side) 21 is formed of a metal conductor formed in a cylindrical shape having a smaller diameter than that of the fixed current-carrying contact 22, the end of which is in the direction of the driving device being rounded. The arc contact (fixed side) 21 is made of a metal containing 10 to 40% of copper and 90 to 60% of tungsten.

The arc contact (fixed side) 21 contacts the outer diameter portion of the trigger electrode 31 of the movable contact portion 3 when the gas circuit breaker 1 is closed. The arc contact (fixed side) 21 is integrally fixed to the fixed contact portion 2 by a support member provided on the inner wall surface of the exhaust cylinder 24 constituting the outer periphery of the fixed contact portion 2. An arc contact (fixed side) 21 is disposed in the arc-extinguishing gas to ignite an arc generated in the arc-extinguishing gas.

The arc contact (fixed side) 21 is fixed and does not contribute to the weight of the movable part to be driven by the drive device 9. Accordingly, the heat capacity and the surface area can be increased, and as a result, the durability of the arc contact (fixed side) 21 can be improved.

It is desirable that the durability of the arc contact (fixed side) 21, the durability of the arc contact (movable side) 41, and the durability of the trigger electrode 31 have the following relationship.
Durability of the arc contact (fixed side) 21 ≧ durability of the arc contact (movable side) 41> Durability of the trigger electrode 31 The arc contact gas flow heated to high temperature collides with the arc contact 21 after acceleration. Therefore, the arc contact (fixed side) 21 is more easily worn than the arc contact (movable side) 41. In addition, it is desirable to reduce the weight of the trigger electrode 31, which is a movable part, as compared with the arc contact (fixed side) 21 and the arc contact (movable side) 41, and at the same time ignite a high temperature arc as described later. Only during a fixed period until the arc is diverted to the arc contact (movable side) 41, and the degree of wear is limited compared to the arc contact (fixed side) 21 and the arc contact (movable side) 41 Because it is

The arc contact (fixed side) 21 is spaced apart from the arc contact (movable side) 41 by a distance at which insulation can be secured after the arc is extinguished. The arc contact (fixed side) 21 and the arc contact (movable side) 41 can be made large because they are fixed and not movable. For this reason, the electric field in the space between the arc contact (fixed side) 21 and the arc contact (movable side) 41 has an even distribution (distribution with less electric field concentration) compared to the conventional case, and the arc contact (fixed side) 21 And the distance between the arc contacts (movable side) 41 can be shortened as compared with the prior art.

Further, the flow rate and the flow velocity of the arc-extinguishing gas sprayed on the arc can be defined by the distance between the insulating nozzle 23 and the arc contact (fixed side) 21 and the arc contact (movable side) 41. When the distance between the arc contact (fixed side) 21 and the insulating nozzle 23 is larger than the distance between the arc contact (movable side) 41 and the insulating nozzle 23, the arc-extinguishing gas blown to the arc is faster It is desirable that it is easy to be exhausted toward the open end.

When the gas circuit breaker 1 is closed, the trigger electrode 31 of the movable contact portion 3 is inserted into the arc contact (fixed side) 21. As a result, the arc contact (fixed side) 21 contacts the trigger electrode 31 of the movable contact 3 and electrically connects the fixed contact 2 and the movable contact 3. When the gas circuit breaker 1 is in a closed state, the arc contact (fixed side) 21 is a conductor that constitutes a part of a current circuit for electrically connecting the lead conductors 7a and 7b.

On the other hand, when the circuit breaker 1 is in the open state, the arc contact (fixed side) 21 separates from the trigger electrode 31 of the movable contact 3 and is generated between the fixed contact 2 and the movable contact 3 Fire an arc that The arc contact (fixed side) 21 constitutes a pair of electrodes disposed to face the trigger electrode 31 and becomes one of the electrodes in contact with the arc when the gas circuit breaker 1 is in an open state. The fixed conductive contact 22 and the movable conductive contact 32 of the movable contact portion 3 are separated prior to the arc contact (fixed side) 21 and the trigger electrode 31 so that the conductive current is fixed to the arc contact (fixed side) 21 and the trigger electrode No arcing occurs in the same part because they are separated after being commutated to the 31 side.

Since the arc contact (fixed side) 21 and the trigger electrode 31 are separated later in time than the fixed current contact 22 and the movable current contact 32, the arc is the arc contact (fixed side) 21 and the trigger electrode 31. Are configured to fire between. As a result, deterioration of the fixed current contact 22 and the movable current contact 32 due to arcing is reduced.

When the gas circuit breaker 1 is in the open state, the movable contact portion 3 is driven by the drive device 9 to drive between the arc contact (fixed side) 21 and the arc contact (movable side) 41 from the open end direction Move in the device direction. Along with this, the trigger electrode 31 also moves between the arc contact (fixed side) 21 and the arc contact (movable side) 41 from the open end direction to the drive device direction. Before the trigger electrode 31 separates from the arc contact (fixed side) 21, the fixed conductive contact 22 and the movable conductive contact 32 separate. This is to prevent an arc from being generated between the fixed energizing contact 22 and the movable energizing contact 32.

The distance between the arc contact (fixed side) 21 and the arc contact (movable side) 41 and the arc contact (fixed side) from when the trigger electrode 31 starts to separate from the arc contact (fixed side) 21 The arc is generated between the trigger electrode 31 and the arc contact (fixed side) 21 until the separation distance between the 21 and the trigger electrode 31 becomes equal.

When the separation distance between the arc contact (fixed side) 21 and the arc contact (movable side) 41 and the separation distance between the arc contact (fixed side) 21 and the trigger electrode 31 become substantially equal, the arc contacts the arc from the trigger electrode 31 Transfer to child (movable side) 41. The arc is extinguished when the separation distance between the arc contact (fixed side) 21 and the arc contact (movable side) 41 and the separation distance between the arc contact (fixed side) 21 and the trigger electrode 31 become approximately equal. The arc is generated between the arc contact (movable side) 41 and the arc contact (fixed side) 21 until the time point. At this time, the arc contact (movable side) 41 and the arc contact (fixed side) 21 constitute a pair of electrodes disposed to face each other to ignite an arc.

The distance between the arc contact (fixed side) 21 and the arc contact (movable side) 41 and the arc contact (fixed side) from when the trigger electrode 31 starts to separate from the arc contact (fixed side) 21 The time until the separation distance between the trigger 21 and the trigger electrode 31 becomes equal may be referred to as "the first half of the current interruption time".

The arc is extinguished from the time when the separation distance between the arc contact (fixed side) 21 and the arc contact (movable side) 41 and the separation distance between the arc contact (fixed side) 21 and the trigger electrode 31 become equal The time until is sometimes called "the second half at the time of current interruption".

The trigger electrode 31 further has a distance between the arc contact (fixed side) 21 and the trigger electrode 31 greater than a distance between the arc contact (fixed side) 21 and the arc contact (movable side) 41 in the drive device direction. Move in the direction The trigger electrode 31 is separated from the arc generated between the arc contact (movable side) 41 and the arc contact (fixed side) 21, and deterioration of the trigger electrode 31 is reduced.

The trigger electrode 31 further moves in the driver direction. Then, the sealed state on the open end direction side of the pressure accumulation chamber 38 configured by the trigger electrode 31 and the arc contact (movable side) 41 is released. As a result, the arc-extinguishing gas pressurized in the compression chamber 36 formed by the piston 33 and the cylinder 42 forms the pressure accumulation chamber 38 and the insulating nozzle 23 formed by the trigger electrode 31 and the arc contactor (movable side) 41. Then, the arc between the arc contact (fixed side) 21 and the arc contact (movable side) 41 is extinguished.

The tip of the arc contact (fixed side) 21 may be divided in the circumferential direction to be a finger-like electrode. In this case, the arc contact (fixed side) 21 has flexibility, and the inner diameter of the opening edge of the arc contact (fixed side) 21 is slightly smaller than the outer diameter of the trigger electrode 31 and shrunk. When the trigger electrode 31 is inserted into the opening of the arc contact (fixed side) 21, the arc contact (fixed side) 21 and the trigger electrode 31 come into contact with each other and conduct.

(Insulation nozzle 23)
The insulating nozzle 23 is a cylindrical flow straightening member having a throat portion 23 a that defines the flow velocity balance of the arc-extinguishing gas pressurized in the compression chamber 36. The insulating nozzle 23 is made of a heat-resistant insulator such as PTFE (polytetrafluoroethylene) resin.

The insulating nozzle 23 is integrally fixed to the fixed contact portion 2 and arranged such that the axis constituting the cylinder of the insulating nozzle 23 is on the cylindrical axis of the arc contact (fixed side) 21.

The insulating nozzle 23 is arranged to surround the trigger electrode 31 when the gas circuit breaker 1 is in a closed state. The insulating nozzle 23 is shaped so as to form a conical space on the inside from the open end direction toward the driving device direction. The insulating nozzle 23 extends along the axis from the arcing contact (fixed side) 21 to the arcing contact (movable side) 41 side, and between the arcing contact (fixed side) 21 and the arcing contact (movable side) 41 It has a throat portion 23a with a small diameter.

The arc extinguishing gas pressurized in the compression chamber 36 is guided to the arc space by the insulating nozzle 23. Further, the arc-extinguishing gas is concentrated in the arc space by the throat portion 23a of the insulating nozzle 23, and the flow velocity of the arc-extinguishing gas is increased in the flow path expanded from the throat portion 23a.

When the gas circuit breaker 1 is opened, the arc extinguishing gas in the compression chamber 36 formed by the piston 33 of the movable contact portion 3 and the cylinder 42 of the fixed contact portion 4 is pressurized. The arc contact (movable side) 41 and the trigger electrode 31 constitute a pressure accumulation chamber 38 for the arc extinguishing gas. At the stage where the arc-extinguishing gas in the compression chamber 36 is pressurized by the piston 33 and the cylinder 42, the trigger electrode 31 is inserted in the arc contact (movable side) 41, and the sealing state is established. There is.

In the final stage of the pressure rising process of the arc-extinguishing gas in the compression chamber 36, the arc contact (movable side) 41 and the trigger electrode 31 are separated, and the pressure is raised in the compression chamber 36 and the arc-extinguishing property accumulated in the pressure accumulation chamber 38 A gas is blown into the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41. At this time, the pressurized arc-extinguishing gas is concentrated in the arc space by the insulating nozzle 23. Thus, the arc between the arc contact (movable side) 41 and the arc contact (fixed side) 21 is efficiently extinguished, and the arc contact (movable side) 41 and the arc contact (fixed side) 21 Are electrically disconnected.

The arc-extinguishing gas blown to the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41 and heated to a high temperature is cooled through the exhaust cylinder 24 of the fixed contact portion 2, After the insulation is recovered, the inside of the closed vessel 8 is exhausted.

Thermal energy generated by the arc discharge is removed by the arc-extinguishing gas. As a result, the arc-extinguishing gas contains heat energy from the arc discharge and reaches high temperature and high pressure. The arc-extinguishing gas which has become high temperature and high pressure is discharged from the

exhaust ports

24a, 24b and 24c of the exhaust cylinder 24, and the heat energy of these is removed from the electrode area.

The insulating nozzle 23 concentrates the arc extinguishing gas pressurized by the throat portion 23a into the arc space. Furthermore, the insulating nozzle 23 accelerates the arc-extinguishing gas in the enlarged portion from the throat portion 23a to enhance the exhaustability of thermal energy. In addition, the insulating nozzle 23 defines an exhaust flow path of the arc extinguishing gas whose temperature is increased by the arc, and suppresses, for example, the dielectric breakdown between the fixed energizing contact 22 and the movable energizing contact 32. Furthermore, the insulating nozzle 23 suppresses the spread of the arc by the throat portion 23a, and defines the minimum diameter of the arc at this portion. Further, the insulating nozzle 23 appropriately controls the flow rate and the flow rate of the arc-extinguishing gas by the throat portion 23a. As a result, the arc-extinguishing gas is efficiently sprayed to the arc generated between the arc contact (movable side) 41 and the arc contact (fixed side) 21, and the thermal energy is efficiently removed. Is extinguished. As a result, the arc contact (movable side) 41 and the arc contact (fixed side) 21 are electrically disconnected.

In the prior art, the insulating nozzle 23 was often provided in the movable contact portion 3 together with the movable conductive contact 32. However, since the movable contact portion 3 is movable, it is desirable to reduce the weight. Therefore, it is desirable that the insulating nozzle 23 be provided in the stationary contact portion 2 which does not move. The insulating nozzle 23 may be provided in the movable contact portion 3.

The insulating nozzle 23 may be installed on either the fixed contact 2 or the movable contact 3, but the movable contact 3 has vibration due to movement. For this reason, compared with the case where it installs in the movable contact part 3, the one at the time of installing in the fixed contact part 2 can suppress the deterioration of the electrical performance by vibration.

Further, the insulating nozzle 23 is preferably installed in the fixed contact portion 2 because the insulating nozzle 23 can suppress the flow of the arc-extinguishing gas, which has a low insulating property and becomes a high temperature, into the fixed conductive contact 22. It is desirable that the clearance distance between the insulating nozzle 23 and the trigger electrode 31 be larger than the clearance distance when the arc contact (fixed side) 21 contacts the trigger electrode 31. In addition, it is desirable that the insulating nozzle 23 and the trigger electrode 31 be arranged not to be in contact with each other even when the trigger electrode 31 is driven. When the insulating nozzle 23 which is a dielectric and the trigger electrode 31 which is a high voltage conductor are in contact with each other, the electrical insulation performance may be impaired.

In blowing the arc-extinguishing gas to the arc generated between the arc contact (movable side) 41 and the arc contact (fixed side) 21, it is desirable that the internal pressure of the insulating nozzle 23 be low. Therefore, the shape of the insulating nozzle 23 is set such that the cross-sectional area of the flow path of the arc-extinguishing gas formed by the arc contact (fixed side) 21 and the insulating nozzle 23 becomes wider toward the open end. Is desirable.

According to the test results, in order to obtain a good blocking performance, it is preferable to use the following channel configuration.
Area of flow passage formed between arc contact (fixed side) 21 and insulating nozzle 23> area of flow passage of throat portion 23a of insulating nozzle 23> area of blowout portion of arc contact (movable side) 41

The insulating nozzle 23 controls the flow of the arc-extinguishing gas jetted out through the compression chamber 36 and the pressure accumulation chamber 38 so as to cool the arc efficiently. The pressure in the insulating nozzle 23 is a downstream pressure when the arc extinguishing gas is jetted, so it is desirable that the pressure be always kept at a low pressure.

The insulating nozzle 23 not only creates a flow of arc-extinguishing gas parallel to the axis from the driver direction to the open end direction, but also creates a flow of arc-extinguishing gas in the direction crossing the arc. This flow effectively cools the arc. It is desirable that the arc-extinguishing gas blown to the arc and heated to a high temperature is exhausted without being in contact with the fixed current contact 22 and the movable current contact 32 because the insulation property is low.

(Exhaust cylinder 24)
The exhaust cylinder 24 is a cylindrical member made of a conductor metal that has been cut out. At the end of the exhaust cylinder 24 in the driving device direction, the axes of the cylinders are aligned, and an arc contact (fixed side) 21 and a fixed conductive contact 22 are disposed. The exhaust cylinder 24 has

exhaust ports

24a, 24b, 24c for discharging the arc-extinguishing gas that has become high temperature. The exhaust cylinder 24 may be integrally formed with the arc contact (fixed side) 21 and the fixed conductive contact 22.

The lead-out conductor 7 a is connected to the exhaust cylinder 24 via the sealed container 8. The exhaust cylinder 24 serves as a flow path of arc-extinguishing gas, and seals the arc-extinguishing gas blown to the arc and brought to a high temperature from the arc space between the arc contact (fixed side) 21 and the trigger electrode 31 Lead to container 8

When the gas circuit breaker 1 is opened, the arc extinguishing gas in the compression chamber 36 formed by the piston 33 of the movable contact portion 3 and the cylinder 42 of the fixed contact portion 4 is boosted, and the arc contact (fixed It blows to the arc space between the side 21 and the arc contact (movable side) 41. The arc-extinguishing gas blown to the arc and heated to a high temperature is discharged from the

exhaust ports

24 a, 24 b and 24 c of the exhaust cylinder 24 into the sealed container 8.

(Fixed contact 4)
The fixed contact portion 4 has an arc contact (movable side) 41, a cylinder 42, and a support 43. The arc contact (movable side) 41 corresponds to a second arc contact in the claims. Also in the text, the arc contact (movable side) 41 may be referred to as a second arc contact.

(Arc contact (movable side) 41)
The arc contact (movable side) 41 is a cylindrical electrode disposed along the central axis of the cylinder of the fixed contact portion 4 and at the end of the fixed contact portion 4 in the open end direction. The arc contact (movable side) 41 is formed of a metal conductor formed in a cylindrical shape having an approximately equal diameter to the stationary conductive contact 22 with a rounded end in the direction of the open end. The arc contact (movable side) 41 is made of, for example, a metal containing 10 to 40% of copper and 90 to 60% of tungsten.

The arc contact (movable side) 41 has an inner diameter having a sliding or fixed clearance with the outer diameter portion of the trigger electrode 31 of the movable contact portion 3. The arc contact (movable side) 41 is fixed by the insulating support member via the support 43 that constitutes the outer periphery of the fixed contact portion 4. The arc contact (movable side) 41 is fixed to the support 43 and does not move. For this reason, the arc contact (movable side) 41 is not included in the movable part weight driven by the drive device 9. Therefore, the heat capacity and the surface area can be improved without increasing the driving force of the drive device 9, and the durability of the arc contact (movable side) 41 can be improved.

The arc contact (movable side) 41 is spaced apart from the arc contact (fixed side) 21 by a distance at which insulation can be secured after the arc is extinguished. Since the arc contact (movable side) 41 and the arc contact (fixed side) 21 are fixed and not movable, the surface area can be increased without increasing the driving force of the drive device 9. Therefore, the electric field distribution between the arc contact (movable side) 41 and the arc contact (fixed side) 21 can be made closer to a uniform electric field, and the arc contact (movable side) 41 and the arc contact (fixed The distance between the sides 21 can be shortened compared to the prior art.

Further, the flow rate of the arc-extinguishing gas sprayed on the arc can be defined by the distance between the insulating nozzle 23 and the arc contact (fixed side) 21 and the arc contact (movable side) 41. It is desirable that the distance between the arc contact (fixed side) 21 and the insulating nozzle 23 be larger than the distance between the arc contact (movable side) 41 and the insulating nozzle 23.

The fixed contact portion 4 and the movable contact portion 3 are configured to be always in the same potential and in the conductive state via a sliding contact or the like. When the gas circuit breaker 1 is in the closed state, the trigger electrode 31 of the movable contact portion 3 is inserted into the arc contact (fixed side) 21, so the fixed contact portion 2 and the fixed contact portion are interposed via the movable contact portion 3 The part 4 is electrically conducted. When the gas circuit breaker 1 is in a closed state, the arc contact (movable side) 41 is a conductor that constitutes a part of an electric circuit for electrically connecting the lead conductors 7a and 7b.

On the other hand, since the trigger electrode 31 of the movable contact portion 3 is separated from the arc contact (fixed side) 21 of the fixed contact portion 2 when the gas circuit breaker 1 is in the open state, the arc contact (movable side) 41 is It is electrically disconnected from the arc contact (fixed side) 21.

However, when the gas circuit breaker 1 is in the open state, the trigger electrode 31 of the movable contact portion 3 and the arc contact (fixed side) 21 of the fixed contact portion 2 are mechanically separated, but the generated arc Are electrically connected. Therefore, in the state where the arc is present, the arc contact (movable side) 41 and the arc contact (fixed side) 21 are in the electrically conductive state.

When the gas circuit breaker 1 is in the open state, the movable contact portion 3 is driven by the drive device 9 to drive between the arc contact (fixed side) 21 and the arc contact (movable side) 41 from the open end direction Move in the device direction. Along with this, the trigger electrode 31 also moves between the arc contact (fixed side) 21 and the arc contact (movable side) 41 from the open end direction to the drive device direction. Before the trigger electrode 31 separates from the arc contact (fixed side) 21, the fixed conductive contact 22 and the movable conductive contact 32 separate. The reason is that an arc does not occur between the fixed energizing contact 22 and the movable energizing contact 32 and always occurs between the trigger electrode 31 and the arc contact (fixed side) 21.

When the separation distance between the arc contact (fixed side) 21 and the arc contact (movable side) 41 and the separation distance between the arc contact (fixed side) 21 and the trigger electrode 31 become equal, the arc is from the trigger electrode 31 to the arc contact (Movable side) Transfer to 41. The arc is extinguished from the time when the separation distance between the arc contact (fixed side) 21 and the arc contact (movable side) 41 and the separation distance between the arc contact (fixed side) 21 and the trigger electrode 31 become equal Up to the moment, an arc is generated between the arc contact (movable side) 41 and the arc contact (fixed side) 21. At this time, the arc contact (movable side) 41 and the arc contact (fixed side) 21 constitute a pair of electrodes disposed facing each other, and bear an arc.

The trigger electrode 31 further moves in the driver direction. Then, the sealed state on the open end direction side of the pressure accumulation chamber 38 configured by the trigger electrode 31 and the arc contact (movable side) 41 is released. Thus, the arc-extinguishing gas pressurized in the compression chamber 36 and stored in the pressure accumulation chamber 38 is spouted through the arc contact (movable side) 41 and the insulating nozzle 23, and the arc contact (fixed side) 21 and The arc between the arc contacts (movable side) 41 is extinguished.

When the trigger electrode 31 is moved in the direction of the drive device by the drive device 9, the arc is transferred from the trigger electrode 31 to the arc contact (movable side) 41. The arc contact (movable side) 41 and the arc contact (fixed side) 21 are electrical final contacts when the gas circuit breaker 1 is in an open state.

Further, when the gas circuit breaker 1 is in the open state, it is desirable to reduce the deterioration of the fixed current contact 22 and the movable current contact 32 due to the arc. The fixed contact 22 and the movable contact 32 are separated, but in order to prevent arcing between the fixed contact 22 and the movable contact 32, an arc contact (fixed side) 21 and a trigger electrode 31, the arc contactor (movable side) 41 bears an arc. For this reason, the trigger electrode 31 and the arc contact (fixed side) 21 maintain a sufficiently high conductivity and contact for a time until the fixed conductive contact 22 and the movable conductive contact 32 are separated, and the electrically conductive state is good. Keep

When the gas circuit breaker 1 is opened, the arc extinguishing gas in the compression chamber 36 formed by the piston 33 of the movable contact portion 3 and the cylinder 42 of the fixed contact portion 4 is pressurized. The arc contact (movable side) 41 and the trigger electrode 31 constitute a pressure accumulation chamber 38 for the arc extinguishing gas. At the stage where the arc-extinguishing gas in the compression chamber 36 is pressurized by the piston 33 and the cylinder 42, the trigger electrode 31 is inserted in the arc contact (movable side) 41, and the sealing state is established. There is. Therefore, the arc-extinguishing gas pressurized in the compression chamber 36 is stored in the pressure accumulation chamber 38.

After the pressure increase of the arc-extinguishing gas in the compression chamber 36 is completed or progressed to a certain degree, the arc contactor (movable side) 41 and the trigger electrode 31 are separated, and the arc-extinguishing gas stored in the accumulator chamber 38 is It is blown into the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41. Thereby, the arc between the arc contact (movable side) 41 and the arc contact (fixed side) 21 is extinguished, and the arc contact (movable side) 41 and the arc contact (fixed side) 21 are electrically Shut off.

The tip of the arc contact (movable side) 41 may be divided in the circumferential direction to be a finger-like electrode. In this case, the arc contact (movable side) 41 has flexibility, and the inner diameter of the opening edge of the arc contact (movable side) 41 is slightly smaller than the outer diameter of the trigger electrode 31 and is shrunk. When the trigger electrode 31 is inserted into the opening of the arc contact (movable side) 41, the trigger electrode 31 and the arc contact (movable side) 41 may be brought into contact with each other and conducted.

(Cylinder 42)
The cylinder 42 is a cylindrical member made of a metal conductor and having a bottom at one end and an opening at the other end. Moreover, the cylinder 42 has a cylindrical inner wall inside, and forms a toroidal space. An inner wall provided inside the cylinder 42 and forming a toroidal space is constituted by an arc contact (movable side) 41. An outer wall constituting an outer peripheral portion of the cylinder 42 is configured to draw a concentric circle with the arc contact (movable side) 41.

The cylinder 42 has an inner diameter slidable with the outer diameter of the piston 33 of the movable contact portion 3. Furthermore, the arc contact (movable side) 41 that constitutes the inner wall of the cylinder 42 has an outer diameter that can slide with the diameter of the donut-like hole of the piston 33.

The cylinder 42 is disposed in the fixed contact portion 4 so that the bottomed portion is in the drive device direction and the opening is in the open end direction. The cylinder 42 is disposed in the arc-extinguishing gas. The cylinder 42 has an insertion hole 42 a in the bottomed portion, through which a piston support 33 a supporting the piston 33 of the movable contact portion 3 is inserted.

In the cylinder 42, a piston 33 is inserted, and the cylinder 42 and the piston 33 form a compression chamber 36 for pressurizing the arc-extinguishing gas. The cylinder 42 and the piston 33 compress the arc-extinguishing gas in the compression chamber 36 when the gas circuit breaker 1 is in the open state. The cylinder 42 and the piston 33 ensure the airtightness of the compression chamber 36. Thereby, the arc-extinguishing gas in the compression chamber 36 is pressurized.

A through hole 42 b is provided in the arc contact (movable side) 41 that constitutes the inner wall of the cylinder 42. The through hole 42 b electrically connects the pressure accumulation chamber 38 configured by the arc contact (movable side) 41 and the trigger electrode 31 to the compression chamber 36. The arc-extinguishing gas pressurized in the compression chamber 36 is temporarily accumulated in the pressure accumulation chamber 38. The pressurized arc-extinguishing gas accumulated in the pressure accumulation chamber 38 is guided to the arc space through the insulating nozzle 23 in the second half of the current interruption time.

A check valve 42 e is provided in the through hole 42 b of the cylinder 42 that communicates the inside of the compression chamber 36 with the pressure accumulation chamber 38. The check valve 42 e prevents the arc-extinguishing gas, which is blown to the arc and becomes high temperature by being blown to the arc, from flowing into the compression chamber 36 from the pressure accumulation chamber 38. The check valve 42e is made of a metal material such as stainless steel.

FIG. 4 shows an enlarged view of the check valve 42e. The check valve 42e has a valve head 42n that opens and closes the pressure accumulation chamber 38 and the compression chamber 36, and a shaft 42m connected to the valve head 42n. The valve head 42 n extends in the direction of the pressure accumulation chamber 38 in the direction of the open end and in the direction of the compression chamber 36 in the direction of the driving device, and is obliquely connected to the shaft 42 m.

The shaft 42 m of the check valve 42 e is disposed in a guide 42 g provided in the fixed contact portion 4. The non-return valve 42 e reciprocates in the direction of the open end, in the direction of the driving device, as the shaft 42 m slides along the guide 42 g. The valve head 42n of the check valve 42e is connected to a spring 42s that applies a force in the direction in which the check valve 42e closes.

In the steady state other than the time of current interruption, the check valve 42e abuts on the end of the arc contact (movable side) 41 constituting the through hole 42b to close the valve, and the arc extinguishing gas and the accumulator chamber 38 are closed. It prevents flowing between the compression chamber 36 and the chamber.

The check valve 42 e is opened in the first half when the current is shut off, and causes the arc-extinguishing gas pressurized in the compression chamber 36 to flow into the pressure accumulation chamber 38. The check valve 42e abuts on the tapered portion 33t of the piston 33 to close in the latter half when current is shut off, and the arc-extinguishing gas blown by the arc and expanded to a high pressure flows from the pressure accumulation chamber 38 into the compression chamber 36 To prevent.

The sum of the force of the spring 42s and the force acting in the direction to close the check valve 42e by the arc-extinguishing gas inside the pressure accumulation chamber 38 opens the check valve 42e by the arc-extinguishing gas inside the compression chamber 36 The check valve 42e closes when the force acting in the direction of movement is greater than the force acting in the direction of movement.

When the gas circuit breaker 1 is in an open state, the cylinder 42 cooperates with the piston 33 to compress the arc-extinguishing gas in the compression chamber 36. As a result, the arc-extinguishing gas in the compression chamber 36 is pressurized. The arc contact (movable side) 41 and the trigger electrode 31 constitute a pressure accumulation chamber 38 for the arc extinguishing gas. At the stage where the arc-extinguishing gas in the compression chamber 36 is pressurized by the piston 33 and the cylinder 42, the trigger electrode 31 is inserted in the arc contact (movable side) 41, and the sealing state is established. There is.

After the pressure increase of the arc-extinguishing gas in the compression chamber 36 is completed or progressed to a certain extent, the arc contact (movable side) 41 and the trigger electrode 31 are separated, and the arc-extinguishing gas pressurized in the compression chamber 36 It flows through the pressure accumulation chamber 38 and is blown to the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41. Thereby, the arc between the arc contact (movable side) 41 and the arc contact (fixed side) 21 is extinguished, and the arc contact (movable side) 41 and the arc contact (fixed side) 21 are electrically Shut off.

The cylinder 42 cooperates with the piston 33 to compress the arc-extinguishing gas in the compression chamber 36. Therefore, the cylinder 42 and the piston 33 are in a sealed state at the time of compression of the arc-extinguishing gas to prevent pressure leak. However, if an excessive pressure due to the compressed arc-extinguishing gas is continuously applied to the piston, the piston 33, the trigger electrode 31, and the movable energizing contact 32 may be caused to reverse. In order to prevent this backward movement, a hole provided with a pressure valve may be provided at the bottom of the cylinder 42 and pressure may be released by appropriately opening and closing. Alternatively, by disposing the check valve 42 e, it is possible to suppress the backward movement of the piston 33, the trigger electrode 31, and the movable energizing contact 32.

The cylinder 42 has an intake hole 42c at the bottom and an intake valve 42d disposed in the intake hole 42c. Again, when the gas circuit breaker 1 is in the closed state, the movable contact portion 3 is moved from the drive device direction to the open end direction by the drive device 9. Along with this, the piston 33 also moves from the drive device direction to the open end direction. At this time, the compression chamber 36 formed by the piston 33 and the cylinder 42 is expanded, and the pressure in the compression chamber 36 is reduced. Due to the drop in pressure in the compression chamber 36, the arc-extinguishing gas in the closed container 8 is sucked into the compression chamber 36 via the intake hole 42c and the intake valve 42d. Since the inhaled arc-extinguishing gas is sufficiently far from the high-temperature arc space, the low-temperature arc-extinguishing gas is charged into the compression chamber 36.

(Support 43)
The support 43 is a cylindrical conductor having one end face with a bottom, and the end face with the bottom is disposed in the direction of the driving device. The lead conductor 7 b is connected to the support 43 via the sealed container 8. The support 43 is fixed to the closed container 8 by an insulating member. The support 43 supports the arc contact (movable side) 41 and the cylinder 42.

(Movable contact 3)
The movable contact portion 3 has a trigger electrode 31, a movable conductive contact 32, a piston 33, an insulating rod 37, and a pressure accumulation chamber 38. In the prior art, the movable contact portion has a nozzle, a cylinder, and an arc electrode, which is large. However, the present embodiment can realize significant weight reduction. The trigger electrode 31 and the piston 33 do not necessarily have to be integrated and operate at the same time, but when they are integrated, the structure can be simplified. In some cases, it is advantageous in terms of the blocking performance that the trigger electrode 31 is moved faster than the piston 33.

(Movable energizing contact 32)
The movable conductive contact 32 is a cylindrical electrode disposed along the central axis of the cylinder of the movable contact portion 3 and at the end of the movable contact portion 3 in the direction of the open end. The movable conductive contact 32 is formed of a cylindrical metal conductor whose end in the open end direction is formed to be rounded. The metal constituting the movable current-carrying contact 32 is desirably aluminum which is highly conductive and light in weight, but may be copper. It is desirable that the movable energizing contact 32 be configured to be lightweight in order to move.

The movable current-carrying contact 32 has an outer diameter capable of coming into contact with and sliding on the inner diameter portion of the fixed current-carrying contact 22 of the fixed contact portion 2. The movable energizing contact 32 is disposed on the surface in the direction of the open end of the piston 33.

When the gas circuit breaker 1 is in a closed state, the movable energizing contact 32 is inserted into the stationary energizing contact 22 of the fixed contact portion 2. As a result, the movable conductive contact 32 comes into contact with the fixed conductive contact 22 and electrically conducts the movable contact portion 3 and the fixed contact portion 2. The movable current-carrying contact 32 has the ability to flow a rated current when it is energized.

On the other hand, when the gas circuit breaker 1 is in the open state, the movable energizing contact 32 physically separates from the fixed energizing contact 22 of the fixed contact portion 2 and electrically connects the movable contact portion 3 and the fixed contact portion 2 Shut off.

The movable conductive contact 32 is integrally formed with a piston 33 formed of a conductor. When the gas circuit breaker 1 is in a closed state or an open state, the piston 33 is inserted into and in contact with the cylinder 42 of the fixed contact 4 to electrically connect the movable contact 3 and the fixed contact 4. Since the piston 33 slides in the cylinder 42 of the fixed contact portion 4, the movable contact portion 3 and the fixed contact portion 4 are electrically conducted regardless of the closed state or open state of the gas circuit breaker 1. It becomes.

(Trigger electrode 31)
The trigger electrode 31 is a rod-like electrode disposed along the central axis of the cylinder of the movable contact portion 3 and at the end of the movable contact portion 3 in the open end direction. The trigger electrode 31 is formed of a solid cylindrical metal conductor whose one end is rounded by cutting or the like. At least the tip of the trigger electrode 31 is made of, for example, a metal containing 10% to 40% of copper and 90% to 60% of tungsten.

The trigger electrode 31 has an outer diameter that can contact and slide with the inner diameter of the arc contact (fixed side) 21 of the fixed contact portion 2. The trigger electrode 31 is disposed further inside the arc contact (movable side) 41. The trigger electrode 31 is disposed inside the arc contact (movable side) 41 so that the durability, weight and surface area in view of heat capacity are advantageous.

The trigger electrode 31 is connected to the insulating rod 37 together with the piston 33, and the insulating rod 37 is driven by the driving device 9 to reciprocate between the fixed contact portion 2 and the fixed contact portion 4. The trigger electrode 31 is movable relative to the arc contact (fixed side) 21. The trigger electrode 31 is disposed in the arc-extinguishing gas and bears the arc discharge generated in the arc-extinguishing gas.

When the gas circuit breaker 1 is open circuited, it is required to interrupt the current quickly. In order to move the movable contact portion 3 at high speed, it is desirable to make the trigger electrode 31 light in weight. However, when the weight of the trigger electrode 31 is reduced, the durability to the arc of the trigger electrode 31 is insufficient.

However, the time for which the trigger electrode 31 bears an arc is about 5 to 10 ms at the beginning of the movement of the trigger electrode 31. During the second half of the time when the trigger electrode 31 moves, the stress due to the heat received by the trigger electrode 31 increases at an accelerated rate, but the arc is transferred to the arc contact (movable side) 41. Therefore, the durability of the trigger electrode 31 against the arc does not matter even if the weight is reduced.

It is desirable that the durability of the arc contact (fixed side) 21, the durability of the arc contact (movable side) 41, and the durability of the trigger electrode 31 have the following relationship.
Durability of the arc contact (fixed side) 21 耐久 Durability of the arc contact (movable side) 41 耐久 Durability of the trigger electrode 31 The arc contact gas flow heated to high temperature collides with the arc contact 21 after acceleration. Therefore, the arc contact (fixed side) 21 is more easily worn than the arc contact (movable side) 41. In addition, it is desirable to reduce the weight of the trigger electrode 31 which is a movable part as compared with the arc contact (fixed side) 21 and the arc contact (movable side) 41. It is only for a fixed period of time until the arc is transferred to the contactor (movable side) 41, and the degree of wear of the trigger electrode 31 is limited compared to the arc contactor (fixed side) 21 and the arc contact (movable side) 41. That's why.

The trigger electrode 31 can be configured to be lightweight by lowering the durability. By making the trigger electrode 31 lightweight, when the drive device 9 having the same driving force is used, the gas circuit breaker 1 can be brought into a closed state more quickly, and the interrupting performance can be enhanced. Further, when the trigger electrode 31 is driven at the same speed, the driving force of the driving device 9 can be reduced, and as a result, the driving device 9 can be reduced in weight and size.

On the other hand, since the arc contact (movable side) 41 is a fixed part that does not move, the disadvantage of the large weight is small, and it can be configured thick. As a result, the arc contact (movable side) 41 can be made more durable than the trigger electrode 31.

The trigger electrode 31 and the arc contact (movable side) 41 constitute a pressure accumulation chamber 38, and a pressure equal to that of the arc extinguishing gas pressurized in the compression chamber 36 is applied. In order to prevent pressure leakage of the pressurized arc-extinguishing gas, it is preferable that the trigger electrode 31 and the arc contact (movable side) 41 be in contact with each other. However, in view of the occurrence of foreign matter, etc., it is preferable that the trigger electrode 31 and the arc contact (movable side) 41 be slightly separated.

The trigger electrode 31 and the arc contact (movable side) 41 preferably have a separation distance of 5 to 15% with respect to the diameter of the trigger electrode 31. In addition, in order to improve the airtightness of the arc-extinguishing gas pressurized in the compression chamber 36 and to prevent the aged deterioration of the airtightness, a gap portion between the trigger electrode 31 and the arc contact (movable side) 41 Preferably, it has a constant length in the axial direction.

The amount or flow path of the arc-extinguishing gas is controlled by the shape or the distance between the trigger electrode 31 and the arc contact (movable side) 41.

When the gas circuit breaker 1 is in a closed state, the trigger electrode 31 is inserted into the arc contact (fixed side) 21 of the fixed contact portion 2. Thereby, the trigger electrode 31 contacts the arc contact (fixed side) 21 of the fixed contact portion 2 and the arc contact (movable side) 41 of the fixed contact portion 4, and the fixed contact portion 2 and the movable contact portion 3. Make the stationary contact portion 4 electrically conductive. When the gas circuit breaker 1 is in the closed state, the trigger electrode 31 is a conductor that constitutes a part of a current circuit for electrically connecting the lead conductors 7a and 7b.

On the other hand, when the gas circuit breaker 1 is in the open state, the trigger electrode 31 separates from the arc contact (fixed side) 21 of the fixed contact portion 2. Thereby, the trigger electrode 31 bears the arc generated between the movable contact portion 3 and the fixed contact portion 2. The movable energizing contact 32 and the stationary energizing contact 22 of the stationary contact portion 2 are separated from each other prior to the arc contact (stationary side) 21 and the trigger electrode 31 so that the energizing current is fixed to the arc contact (stationary side) 21 and the trigger electrode No arcing occurs between the movable current contact 32 and the fixed current contact 22 because they are separated after being commutated to 31. The trigger electrode 31 constitutes a pair of electrodes disposed to face the arc contact (fixed side) 21 and becomes one of the electrodes in contact with the arc when the gas circuit breaker 1 is in an open state.

An arc generated when the gas circuit breaker 1 is in an open state is concentrated between the trigger electrode 31 and the arc contact (fixed side) 21. The occurrence of an arc between the movable current-carrying contact 32 and the fixed current-carrying contact 22 is avoided, and the deterioration of the movable current-carrying contact 32 and the fixed current-carrying contact 22 is reduced.

The trigger electrode 31 further moves in the driver direction. Then, the sealed state on the open end direction side of the pressure accumulation chamber 38 configured by the trigger electrode 31 and the arc contact (movable side) 41 is released. As a result, the arc-extinguishing gas which is pressurized in the compression chamber 36 and stored in the pressure accumulation chamber 38 formed of the trigger electrode 31 and the arc contact (movable side) 41 is ejected through the insulating nozzle 23 and arc contact The arc between the child (fixed side) 21 and the arc contact (movable side) 41 is extinguished.

After the pressure increase of the arc-extinguishing gas in the compression chamber 36 is completed or progressed to a certain extent or more, the arc contactor (movable side) 41 and the trigger electrode 31 are separated and boosted in the compression chamber 36 and stored in the pressure accumulation chamber 38 The arc-extinguishing gas thus blown is blown into the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41. Thereby, the arc between the arc contact (movable side) 41 and the arc contact (fixed side) 21 is extinguished, and the arc contact (movable side) 41 and the arc contact (fixed side) 21 are electrically Shut off. After the arc is extinguished, no arc current flows in the trigger electrode 31.

The movement of the trigger electrode 31 with respect to the arc contact (fixed side) 21 and the arc contact (movable side) 41 is caused by an insulating rod 37 fixedly supported on the trigger electrode 31 and the piston 33. The insulating rod 37 is driven by the drive device 9. The insulating rod 37 is made of an insulating material. The insulating rod 37 is disposed on the central axis of the trigger electrode 31, the arc contact (fixed side) 21, and the arc contact (movable side) 41.

The trigger electrode 31 may have a suppressing portion that suppresses the runaway of the arc. Further, the trigger electrode 31 may have a rectifying unit that rectifies the arc-extinguishing gas flowing in the pressure accumulation chamber 38 that guides the gas to the arc. The suppression unit that suppresses the runaway of the arc and the rectification unit that rectifies the arc-extinguishing gas may be integrated with the trigger electrode 31.

(Piston 33)
The piston 33 is a doughnut-shaped plate disposed on the end face of the movable contact portion 3 in the open end direction. The piston 33 has a movable conductive contact 32 on the surface in the direction of the open end. The piston 33 is formed of a metal conductor formed on a doughnut-shaped plate by cutting or the like.

The piston 33 has an outer diameter slidable with the inner diameter of the cylinder 42 of the fixed contact portion 4. The piston 33 has a donut-like hole diameter that can slide on the outer periphery of the arc contact (movable side) 41 that constitutes the inner wall of the cylinder 42 of the fixed contact portion 4.

The piston 33 has a plurality of piston supports 33a connected to the face in the drive direction. The piston support 33a is a member constituted by a metal conductor formed in a rod shape. The piston support 33 a fixes the piston 33 to the trigger electrode 31 via the insertion hole 42 a of the cylinder 42. The piston 33 is connected to the insulating rod 37 via the piston support 33 a and the trigger electrode 31.

The piston 33 is slidably inserted and disposed in the cylinder 42 of the fixed contact portion 4. The piston 33 and the cylinder 42 form a compression chamber 36 for pressurizing the arc-extinguishing gas. The piston 33 is disposed in the arc-extinguishing gas.

The piston 33 is reciprocally moved by the drive device 9 via the insulating rod 37. The reciprocating movement by the driving device 9 is performed when the gas circuit breaker 1 is closed and opened.

When the gas circuit breaker 1 is opened, the piston 33 cooperates with the cylinder 42 to compress the arc-extinguishing gas in the compression chamber 36. As a result, the arc-extinguishing gas in the compression chamber 36 is pressurized. The trigger electrode 31 and the arc contact (movable side) 41 constitute a pressure accumulation chamber 38 for storing the pressurized arc-extinguishing gas.

The pressure accumulation chamber 38 and the compression chamber 36 communicate with each other through a through hole 42 b provided in the cylinder 42. At the stage where the arc-extinguishing gas in the compression chamber 36 is pressurized by the piston 33 and the cylinder 42, the trigger electrode 31 is inserted into the arc contactor (movable side) 41 and the pressure storage chamber 38 is sealed. prevent. Therefore, the inside of the compression chamber 36 and the pressure accumulation chamber 38 are filled with the arc-extinguishing gas pressurized to the same pressure.

A check valve 42 e is provided in the through hole 42 b of the cylinder 42 that communicates the inside of the compression chamber 36 with the pressure accumulation chamber 38. The check valve 42 e prevents the arc-extinguishing gas, which is blown to the arc and becomes high temperature by being blown to the arc, from flowing into the compression chamber 36 from the pressure accumulation chamber 38.

The piston 33 has a tapered portion 33t in contact with the check valve 42e on the surface on the drive device direction side. The tapered portion 33t is a surface obliquely provided on the surface of the piston 33 on the drive device direction side in which the inner diameter direction extends in the open end direction and the outer diameter direction extends in the drive device direction. The tapered portion 33t of the piston 33 closes in contact with the check valve 42e at the time of closing the valve, closes the valve, blows to the arc, and the arc-extinguishing gas expanded to a high pressure flows back to the compression chamber 36 via the pressure accumulation chamber 38. prevent.

Further, in the compression chamber 36 constituted by the piston 33 and the cylinder 42, and in the pressure accumulation chamber 38 constituted by the trigger electrode 31 and the arc contact (movable side) 41, the arc-extinguishing gas in the compression chamber 36 is boosted. The stage is sealed and isolated from the arc. The pressurized arc-extinguishing gas in the compression chamber 36 and the pressure accumulation chamber 38 is at a low temperature because it is less susceptible to the heat of the arc. Since a low temperature arc extinguishing gas is blown to the arc between the arc contact (movable side) 41 and the arc contact (fixed side) 21, arc extinction is efficiently performed.

The piston 33 receives pressure of an arc generated between the trigger electrode 31 or the arc contact (movable side) 41 and the arc contact (fixed side) 21 and the pressure of arc-extinguishing gas heated by the arc, but This pressure acts as a force to move the entire movable contact portion 3 toward the drive device. Thereby, the output of the drive device 9 can be reduced, and as a result, the drive device 9 can be miniaturized.

After the pressure increase of the arc-extinguishing gas in the compression chamber 36 is completed or progressed to a certain extent or more, the trigger electrode 31 and the arc contact (movable side) 41 are separated and pressurized in the compression chamber 36 and stored in the pressure accumulation chamber 38. An arc extinguishing gas is blown into the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41. Thereby, the arc between the arc contact (movable side) 41 and the arc contact (fixed side) 21 is extinguished, and the arc contact (movable side) 41 and the arc contact (fixed side) 21 are electrically Shut off.

Heat generated by arc generated between the arc contact (fixed side) 21 and the trigger electrode 31 or between the arc contact (fixed side) 21 and the arc contact (movable side) 41 Simultaneously with the generation thereof, the gas is quickly exhausted into the sealed container 8 through the

exhaust ports

24a, 24b, 24c and the like.

(Insulation rod 37)
The insulating rod 37 is a rod-like member made of an insulating material. The trigger electrode 31 and the piston 33 are fixed in the direction of the open end of the insulating rod 37. The drive direction of the insulating rod 37 is connected to the drive 9.

The insulating rod 37 is disposed on the central axis of the trigger electrode 31, the arc contact (fixed side) 21, and the arc contact (movable side) 41. The trigger electrode 31 is provided upright at the end of the insulating rod 37 in the direction of the open end.

The insulating rod 37 reciprocates the trigger electrode 31 and the piston 33 while maintaining electrical insulation between the drive device 9 and the closed vessel 8. The reciprocating movement of the insulating rod 37 is performed by the drive device 9. The reciprocating movement by the driving device 9 is performed when the gas circuit breaker 1 is closed and opened.

[1-3. Action]
Next, the operation of the gas circuit breaker 1 of the present embodiment will be described based on FIGS. 1 to 3.

[A. When the gas circuit breaker 1 is closed]
First, the case where the gas circuit breaker 1 of the present embodiment is in the closed state will be described. The gas circuit breaker 1 conducts the current flowing through the lead conductors 7a and 7b in the closed state.

When the gas circuit breaker 1 is in the closed state, the fixed contact portion 2 and the fixed contact portion 4 are electrically connected via the movable contact portion 3 to conduct the current between the lead conductors 7a and 7b. Specifically, the movable conductive contact 32 of the movable contact portion 3 is inserted into the fixed conductive contact 22 of the fixed contact portion 2. As a result, the stationary conductive contact 22 contacts the movable conductive contact 32, and the stationary contact portion 2 and the movable contact portion 3 are electrically conducted.

Also, the trigger electrode 31 of the movable contact portion 3 is inserted into the arc contact (fixed side) 21 of the fixed contact portion 2. Thereby, the arc contact (fixed side) 21 contacts the trigger electrode 31, and the fixed contact portion 2 and the movable contact portion 3 are brought into electrical conduction.

Further, the piston 33 of the movable contact portion 3 is inserted into the cylinder 42 of the fixed contact portion 4. The piston 33 and the movable energizing contact 32 are integrally formed and electrically conducted. As a result, the movable conductive contact 32 is electrically connected to the cylinder 42, and the fixed contact portion 4 and the movable contact portion 3 are electrically connected.

As a result, the stationary contact portion 2 and the stationary contact portion 4 are electrically connected via the movable contact portion 3, and the lead-out conductors 7a and 7b are electrically connected.

In this state, no arc occurs in the space between the trigger electrode 31 or the arc contact (movable side) 41 and the arc contact (fixed side) 21. In addition, the arc-extinguishing gas has a uniform pressure at each part in the closed container 8. Therefore, the arc-extinguishing gas in the compression chamber 36 formed by the piston 33 of the movable contact portion 3 and the cylinder 42 of the fixed contact portion 4 is not boosted either. In addition, the arc-extinguishing gas in the pressure accumulation chamber 38 is not boosted.

When the gas circuit breaker 1 is in a closed state, the pressure of the arc extinguishing gas in the closed vessel 8 is uniform. Therefore, no gas flow of arc-extinguishing gas is generated.

[B. When the gas circuit breaker 1 becomes open circuit]
Next, the case where the gas circuit breaker 1 of the present embodiment is in the open state will be described. The gas circuit breaker 1 is in the open state, and cuts off the current flowing to the lead conductors 7a and 7b.

The shutoff operation to open the gas circuit breaker 1 is performed when the gas circuit breaker 1 is switched from the conduction state to the shutoff state when the accident current or the load current is shut off or the transmission circuit is switched.

When the gas circuit breaker 1 is switched from the closed state to the open state, the drive device 9 is driven. The movable contact portion 3 is moved along the axis in the fixed contact portion 4 by the drive device 9 in the direction of the drive device. As a result, the movable conductive contact 32 separates from the fixed conductive contact 22, and the trigger electrode 31 separates from the arc contact (fixed side) 21.

When the gas circuit breaker 1 is in the open state, the movable contact portion 3 is driven by the drive device 9 to move between the fixed contact portion 2 and the fixed contact portion 4 from the open end direction toward the drive device . Along with this, the movable conductive contact 32 separates from the fixed conductive contact 22 and moves from the open end direction to the drive device direction.

Furthermore, the trigger electrode 31 also moves between the arc contact (fixed side) 21 and the arc contact (movable side) 41 from the open end direction toward the drive device. Before the trigger electrode 31 separates from the arc contact (fixed side) 21, the fixed conductive contact 22 and the movable conductive contact 32 separate. As a result, the current to be cut off is diverted to the trigger electrode 31 and the arc contact (fixed side) 21 side, and an arc is not generated between the fixed conductive contact 22 and the movable conductive contact 32.

When the gas circuit breaker 1 is in the open state, the movable contact portion 3 is driven by the drive device 9 so that the piston 33 also moves from the open end direction to the drive device direction. The piston 33 cooperates with the cylinder 42 to compress the arc-extinguishing gas in the compression chamber 36. As a result, the arc-extinguishing gas in the compression chamber 36 is pressurized. The arc contact (movable side) 41 and the trigger electrode 31 constitute a pressure accumulation chamber 38 for storing the pressurized arc-extinguishing gas. When the arc-extinguishing gas in the compression chamber 36 is pressurized by the piston 33 and the cylinder 42, the trigger electrode 31 is inserted into the arc contact (movable side) 41, and the pressure accumulation chamber 38 is It is sealed.

The trigger electrode 31 is driven by the drive 9 and further moves in the direction of the drive. After the pressure increase of the arc-extinguishing gas in the compression chamber 36 is completed or the pressure increase proceeds to a certain degree, the arc contact (movable side) 41 and the trigger electrode 31 are separated, and the open end direction of the arc contact (movable side) 41 At the end of the nozzle, a spout is formed. The arc-extinguishing gas pressurized in the compression chamber 36 and stored in the pressure accumulation chamber 38 spouts from the spout portion, and an arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41 Sprayed on Thereby, the arc between the arc contact (movable side) 41 and the arc contact (fixed side) 21 is extinguished, and the arc contact (movable side) 41 and the arc contact (fixed side) 21 are electrically Shut off.

The insulating nozzle 23 guides the arc-extinguishing gas which flows through the pressure accumulation chamber 38 and is ejected from the spout to the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41.

The throat portion 23a of the insulating nozzle 23 raises the pressure of the arc-extinguishing gas, and increases the flow rate of the arc-extinguishing gas sprayed to the arc in the enlarged flow path downstream of the throat portion 23a. The throat portion 23a of the insulating nozzle 23 concentrates the pressurized arc-extinguishing gas into the arc space. In addition, the insulating nozzle 23 defines an exhaust flow path of the arc-extinguishing gas whose temperature is increased by the arc. Furthermore, the insulating nozzle 23 suppresses the spread of the arc by the throat portion 23a and defines the maximum diameter of the arc. In addition, the insulating nozzle 23 controls the flow rate of the arc-extinguishing gas by the throat portion 23a. Thereby, the arc-extinguishing gas is effectively sprayed to the arc generated between the arc contact (movable side) 41 and the arc contact (fixed side) 21, and the arc is extinguished. As a result, the arc contact (movable side) 41 and the arc contact (fixed side) 21 are electrically disconnected.

The insulating nozzle 23 may be installed on either the fixed contact 2 or the movable contact 3, but the movable contact 3 has vibration and impact due to its movement. Therefore, compared with the case where the insulating nozzle 23 is installed in the fixed contact portion 2 is installed in the movable contact portion 3, the deterioration of the electrical performance due to vibration and the breakage of the insulating nozzle 23 due to mechanical impact are suppressed can do.

Further, the insulating nozzle 23 is preferably installed in the fixed contact portion 2 because the insulating nozzle 23 can suppress the flow of the arc-extinguishing gas, which has a low insulating property and becomes a high temperature, into the fixed conductive contact 22. It is desirable that the clearance distance between the insulating nozzle 23 and the trigger electrode 31 be larger than the clearance distance when the arc contact (movable side) 41 contacts the trigger electrode 31. When the insulating nozzle 23 and the trigger electrode 31 come in contact with each other, a high electric field portion is generated to cause a significant deterioration of the electrical performance. By configuring as described above, the maximum displacement width from the central axis of the trigger electrode 31 can be limited by the inner diameter of the arc contact (movable side) 41, and the contact between the trigger electrode 31 and the insulating nozzle 23 is prevented. be able to. Further, by limiting the clearance distance between the arc contact (movable side) 41 and the trigger electrode 31, it is possible to suppress the amount of leak of the arc-extinguishing gas from the pressure accumulation chamber 38.

In blowing the arc-extinguishing gas to the arc generated between the arc contact (movable side) 41 and the arc contact (fixed side) 21, it is desirable that the internal pressure of the insulating nozzle 23 be low. Therefore, the shape of the insulating nozzle 23 is such that the flow passage cross-sectional area of the flow path of the arc-extinguishing gas formed by the arc contact (fixed side) 21 and the insulating nozzle 23 gradually expands toward the open end. It is desirable to

According to the test results, in order to obtain a good blocking performance, it is preferable to use the following channel configuration.
The area of the flow path formed between the arc contact (fixed side) 21 and the insulating nozzle 23> the area of the flow path of the throat portion 23a of the insulation nozzle 23 面積 the area of the blowout portion of the arc contact (movable side) 41 The area of the flow path formed between the arc contact (movable side) 41 and the insulating nozzle 23 has an appropriate value between 20% and 200% of the area of the blowout portion of the arc contact (movable side) 41 It turned out to be. By configuring in this manner, while maximizing the arc cooling performance in the vicinity of the arc-extinguishing gas outlet of the arc contact (movable side) 41, the arc-extinguishing gas directed from the throat portion 23a of the insulating nozzle 23 toward the open end Gas flow can be supplied sufficiently.

The insulating nozzle 23 controls the arc-extinguishing gas jetted out through the compression chamber 36 and the pressure accumulation chamber 38 so as to cool the arc efficiently. The pressure in the insulating nozzle 23 is a downstream pressure when the arc extinguishing gas is jetted, so it is desirable that the pressure be always kept at a low pressure.

The arc generated in the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41 is very hot. The arc-extinguishing gas blown to the arc and heated to a high temperature is discharged from the

exhaust ports

24 a, 24 b and 24 c of the exhaust cylinder 24 into the sealed container 8.

At the current zero point of the alternating current supplied from the lead-out conductors 7a and 7b, the arc of the arc contact (fixed side) 21 and the arc contact (movable side) 41 becomes smaller, and the arc extinguishing gas is sprayed to extinguish the arc Lead to As a result, the gas circuit breaker 1 is opened, and the current flowing to the lead conductors 7a and 7b is interrupted.

Next, the operation of the check valve 42e will be described based on FIG. The spring 42s applies a force to the valve head 42n of the check valve 42e in a direction to close the check valve 42e. The arc-extinguishing gas inside the pressure accumulation chamber 38 gives the valve head 42n of the check valve 42e a force acting in the direction to close the check valve 42e. The arc-extinguishing gas inside the compression chamber 36 provides a force acting to open the check valve 42e.

That is, when the forces Fa, Fb, and Fs have the following relationship, the check valve 42e is closed.
Fa <Fb + Fs... (Equation 1)
Fa: Force that the arc-extinguishing gas inside the compression chamber 36 opens the check valve 42 e Fb: Force that the arc-extinguishing gas inside the pressure accumulation chamber 38 closes the check valve 42 e Fs: The spring 42 s is the check valve Force to close 42e

Further, when the forces Fa, Fb, and Fs have the following relationship, the check valve 42e is opened.
Fa F Fb + Fs · · · · · (Equation 2)

[A. When the gas circuit breaker 1 is closed]
First, the operation of the check valve 42e when the gas circuit breaker 1 is in the closed state will be described. FIG. 4A shows the state of the check valve 42e when the gas circuit breaker 1 is in the closed state.

When the gas circuit breaker 1 is in a closed state, the arc-extinguishing gas inside the compression chamber 36 and the arc-extinguishing gas inside the pressure accumulation chamber 38 are at normal pressure and equal. That is, the force Fa for the arc-extinguishing gas inside the compression chamber 36 to open the check valve 42e is equal to the force Fb for the arc-off gas inside the pressure accumulation chamber 38 to close the check valve 42e. The forces of Fa, Fb, and Fs have the following relationship.
Fa <Fb + Fs... (Equation 3)
Therefore, the check valve 42e closes.

When the gas circuit breaker 1 is in a closed state, the check valve 42e is in contact with the end of the arc contact (movable side) 41 constituting the through hole 42b to close the valve, and the arc extinguishing is performed. Gas is prevented from flowing between the pressure accumulation chamber 38 and the compression chamber 36.

[B. First half of current interruption]
Next, the operation of the check valve 42e in the first half of the current interruption of the gas circuit breaker 1 will be described. FIG. 4B shows the state of the check valve 42 e in the first half of the current interruption of the gas circuit breaker 1.

In the first half of the current interruption time in which the gas circuit breaker 1 is in the open state, the movable contact portion 3 is driven by the drive device 9, and the piston 33 moves from the open end direction toward the drive device. The piston 33 cooperates with the cylinder 42 to compress the arc-extinguishing gas in the compression chamber 36. As a result, the arc-extinguishing gas in the compression chamber 36 is pressurized. At this stage, the pressure accumulation chamber 38 is in a state in which the trigger electrode 31 is inserted in the arc contact (movable side) 41, and is in a sealed state.

Therefore, the pressure of the arc-extinguishing gas inside the compression chamber 36 is higher than the pressure of the arc-extinguishing gas inside the pressure accumulation chamber 38 in the first half of the current interruption of the gas circuit breaker 1. That is, the force Fa for the arc-extinguishing gas inside the compression chamber 36 to open the check valve 42 e and the force Fb for the arc-off gas inside the pressure accumulation chamber 38 to close the check valve 42 e have the following relationship.
Fa F Fb + Fs · · · · · (Equation 4)
Therefore, the check valve 42e opens.

The check valve 42 e is opened in the first half when the current is shut off, and causes the arc-extinguishing gas pressurized in the compression chamber 36 to flow into the pressure accumulation chamber 38. The check valve 42e has a valve head 42n that opens and closes the pressure accumulation chamber 38 and the compression chamber 36, and a shaft 42m connected to the valve head 42n.

The shaft 42 m of the check valve 42 e is disposed in a guide 42 g provided in the fixed contact portion 4. The non-return valve 42e moves in the direction of the drive and opens as the shaft 42m slides along the guide 42g.

[C. Second half at the time of current interruption]
Next, the operation of the check valve 42e in the second half of the current interruption of the gas circuit breaker 1 will be described. FIG. 4C shows the state of the check valve 42 e in the second half of the current interruption of the gas circuit breaker 1.

The arc-extinguishing gas pressurized in the compression chamber 36 is opened in the check valve 42 e in the first half of the current interruption time, and temporarily accumulated in the pressure accumulation chamber 38. The trigger electrode 31 is driven by the drive 9 and further moves in the direction of the drive.

After the pressure increase of the arc-extinguishing gas in the compression chamber 36 is completed or the pressure increase proceeds to a certain degree, the arc contact (movable side) 41 and the trigger electrode 31 are separated, and the open end direction of the arc contact (movable side) 41 At the end of the nozzle, a spout is formed. The arc-extinguishing gas pressurized in the compression chamber 36 flows through the pressure accumulation chamber 38 and spouts from the spout portion, and into the arc space between the arc contact (fixed side) 21 and the arc contact (movable side) 41 Be sprayed. As a result, the arc between the arc contact (movable side) 41 and the arc contact (fixed side) 21 is extinguished.

The arc generated between the arc contact (fixed side) 21 and the arc contact (movable side) 41 has a high temperature. For this reason, in a period in which the breaking current is in the vicinity of the AC peak value, the arc-extinguishing gas blown to the arc becomes high temperature and high pressure and flows into the pressure accumulation chamber 38.

The high temperature, high pressure arc-extinguishing gas flows into the pressure accumulation chamber 38, so the pressure of the arc-extinguishing gas inside the pressure accumulation chamber 38 is higher than the pressure of the arc-extinguishing gas inside the compression chamber 36 Become. That is, the force Fa for the arc-extinguishing gas inside the compression chamber 36 to open the check valve 42 e and the force Fb for the arc-off gas inside the pressure accumulation chamber 38 to close the check valve 42 e have the following relationship.
Fa <Fb + Fs... (Equation 5)
Therefore, the check valve 42e closes.

The check valve 42 e is closed in the second half when the current is shut off and prevents the arc-extinguishing gas blown to the high temperature from being blown from the arc from flowing into the compression chamber 36 from the pressure accumulation chamber 38.

The shaft 42m of the check valve 42e is disposed in the guide 42g provided in the fixed contact portion 4, and the check valve 42e moves in the direction of the open end and closes as the shaft 42m slides along the guide 42g. To speak.

The piston 33 has a tapered portion 33t in contact with the check valve 42e on the surface on the drive device direction side. The tapered portion 33t of the piston 33 abuts against the check valve 42e, closes the valve, blows to the arc, and becomes a high temperature and high pressure to prevent backflow of the arc-extinguishing gas back to the compression chamber 36 via the pressure accumulation chamber 38 .

If the expanded arc-extinguishing gas flows into the compression chamber 36, the piston 33 constituting the compression chamber 36 is made to go backward, and the arc-extinguishing gas is not sufficiently pressurized and sprayed to the arc through the pressure accumulation chamber 38. This is undesirable because it reduces the flow rate of the arc-extinguishing gas. In addition, when the piston 33 reverses, the trigger electrode 31 moving in conjunction with the piston 33 also reverses, and the trigger electrode 31 seals the spout of the arc contact (movable side) 41, and the arc is blown to the arc This is undesirable because it reduces the flow rate of the arc gas. The check valve 42 e prevents the arc-extinguishing gas, which is blown to the arc and becomes high temperature by being blown to the arc, from flowing into the compression chamber 36 from the pressure accumulation chamber 38. Furthermore, the check valve 42e separates the compression chamber 36 and the pressure accumulation chamber 38 and makes the compression chamber 36 an independent space, so that if the piston 33 moves backward, the compression chamber 36 is expanded along with the expansion of the volume of the compression chamber 36. Since the pressure of 36 is rapidly reduced, retrogression is suppressed, and as a result, the trigger electrode 31 is prevented from sealing the spout of the arc contact (movable side) 41.

The compression chamber 36 has a piston 33 for compressing an arc-extinguishing gas, and the check valve 42 e abuts on the piston 33 to close in the latter half of the current interruption time. Therefore, the stroke of the piston 33 in the compression chamber 36 can be increased. As a result, the flow rate of the arc-extinguishing gas ejected to the arc can be increased.

The piston 33 has a tapered portion 33t in contact with the check valve 42e, and when the valve is closed, the tapered portion 33t contacts the check valve 42e. The tapered portion 33t can reduce the area of the piston 33 in contact with the check valve 42e. For this reason, the pressing force between the check valve 42e and the contact portion between the piston 33 and the piston 33 becomes high, and the degree of adhesion between the piston 33 and the check valve 42e can be improved.

Further, the tapered portion 33t of the piston 33 is formed at an angle such that the inner diameter side is in contact with the check valve 42e and the outer diameter side is not in close contact with the check valve 42e. Therefore, the contact area between the piston 33 and the check valve 42e can be reduced, and as a result, the response speed of the valve opening and the valve closing can be improved. The above is the operation of the check valve 42e.

[1-4. effect]
(1) According to the present embodiment, since the through hole 42 b connecting the pressure accumulation chamber 38 and the compression chamber 36 has the check valve 42 e for preventing the flow of arc-extinguishing gas from the pressure accumulation chamber 38 into the compression chamber 36, It is possible to provide the gas circuit breaker 1 capable of reducing a decrease in the flow rate of the arc-extinguishing gas ejected to the arc.

The arc generated between the arc contact (fixed side) 21 and the arc contact (movable side) 41 at the time of current interruption becomes high temperature. For this reason, the arc-extinguishing gas blown to the arc also becomes high temperature and expands, and also becomes higher in pressure than the arc-extinguishing gas pressurized by means of pressure increase. The arc-extinguishing gas expanded to a high pressure tends to flow back to the compression chamber 36 via the pressure accumulation chamber 38. If the expanded arc-extinguishing gas flows into the compression chamber 36, the piston 33 constituting the compression chamber 36 is made to go backward, and the arc-extinguishing gas is not sufficiently pressurized and sprayed to the arc through the pressure accumulation chamber 38. Flow rate of the arc-extinguishing gas to be reduced. In addition, when the piston 33 reverses, the trigger electrode 31 moving in conjunction with the piston 33 also reverses, and the trigger electrode 31 seals the spout of the arc contact (movable side) 41, and the arc is blown to the arc The flow rate of the arc gas will be reduced.

However, according to the present embodiment, the through hole 42 b communicating the pressure accumulation chamber 38 with the compression chamber 36 includes the check valve 42 e for preventing the flow of arc-extinguishing gas from the pressure accumulation chamber 38 into the compression chamber 36. It is possible to prevent the arc-extinguishing gas, which is blown to the high temperature from becoming high pressure, from flowing into the compression chamber 36 from the pressure accumulation chamber 38. Furthermore, the check valve 42e separates the compression chamber 36 and the pressure accumulation chamber 38 and makes the compression chamber 36 an independent space, so that if the piston 33 moves backward, the compression chamber 36 is expanded along with the expansion of the volume of the compression chamber 36. Since the pressure of 36 is rapidly reduced, retrogression is suppressed, and as a result, the trigger electrode 31 is prevented from sealing the spout of the arc contact (movable side) 41. As a result, it is possible to provide the gas circuit breaker 1 capable of reducing the decrease in the flow rate of the arc-extinguishing gas ejected to the arc.

(2) According to the present embodiment, the check valve 42e opens in the first half when the current is interrupted, and causes the arc-extinguishing gas pressurized in the compression chamber 36 to flow into the pressure accumulation chamber 38, thereby interrupting the current The gas circuit breaker 1 is closed in the second half and prevents the inflow of arc-extinguishing gas from the pressure accumulation chamber 38 to the compression chamber 36, thereby providing a gas circuit breaker 1 capable of reducing a decrease in the flow rate of the arc-extinguishing gas ejected into the arc. can do.

The check valve 42 e is opened in the first half when the current is shut off, so that the arc-extinguishing gas pressurized in the compression chamber 36 can flow into the pressure accumulation chamber 38. In addition, since the check valve 42e closes in the second half when the current is shut off, it is possible to prevent the arc-extinguishing gas blown to the arc from being pressurized and expanded into the compression chamber 36 from the pressure accumulation chamber 38. As a result, it is possible to provide the gas circuit breaker 1 capable of reducing the decrease in the flow rate of the arc-extinguishing gas ejected to the arc.

(3) According to the present embodiment, the check valve 42e is connected to the spring 42s that applies a force in the direction in which the check valve 42e closes the valve, and the force of the spring 42s and the arc-extinguishing gas inside the pressure accumulation chamber 38 When the sum of the force acting in the direction to close the check valve 42e by the valve is larger than the force acting in the direction to open the check valve 42e by the arc-extinguishing gas inside the compression chamber 36, the check valve 42e By closing the valve, it is possible to provide the gas circuit breaker 1 capable of reducing a decrease in the flow rate of the arc-extinguishing gas ejected to the arc.

The arc generated between the arc contact (fixed side) 21 and the arc contact (movable side) 41 at the time of current interruption becomes high temperature. Therefore, the arc-extinguishing gas blown to the arc also becomes high temperature and expands, and also becomes higher in pressure than the arc-extinguishing gas pressurized by the compression chamber 36. The sum of the force of the spring 42s and the force acting in the direction to close the check valve 42e by the arc-extinguishing gas inside the pressure accumulation chamber 38 opens the check valve 42e by the arc-extinguishing gas inside the compression chamber 36 The check valve 42e closes when the force acting in the direction of movement is greater than the force acting in the direction of movement. Therefore, the arc-extinguishing gas blown to the arc and expanded to a high pressure can be prevented from flowing backward to the compression chamber 36 via the pressure accumulation chamber 38.

(4) According to the present embodiment, the compression chamber 38 has the piston 33 for compressing the arc-extinguishing gas, and the check valve 42 e contacts the piston 33 in the latter half of the current interruption time to close the valve. The stroke of the piston 33 in the compression chamber 36 can be increased. As a result, the flow rate of the arc-extinguishing gas ejected to the arc can be increased.

(5) According to the present embodiment, the piston 33 has the tapered portion 33t in contact with the check valve 42e, and when the valve is closed, the tapered portion 33t contacts the check valve 42e. The degree of adhesion to 42e can be improved. By improving the degree of adhesion between the piston 33 and the check valve 42e, the arc-extinguishing gas blown to the arc and expanded to a high pressure more reliably is prevented from flowing back to the compression chamber 36 via the pressure accumulation chamber 38. be able to.

(6) According to the present embodiment, the tapered portion 33t of the piston 33 is formed at an angle such that the inner diameter side is in contact with the check valve 42e and the outer diameter side is not in close contact with the check valve 42e. The contact area with the stop valve 42e can be reduced, and as a result, the response speed of opening and closing can be improved.

[2. Other embodiments]
While the embodiments have been described including variations, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various 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 the equivalents thereof as well as included in the scope and the gist of the invention. The following is an example.

In the above embodiment, the fixed contact portion 2 and the fixed contact portion 4 are fixed to the sealed container 8, but even if the fixed contact portion 2 and the fixed contact portion 4 are movable Good. When the gas circuit breaker 1 is in the open state, for example, the fixed contactor portion 2 may be moved in the open end direction. In addition, the fixed contact portion 4 may be movable in the driving device direction. By moving the fixed

contact

2 or 4 or the fixed

contacts

2 and 4, the power between the lead-out conductors 7 a and 7 b can be cut off more quickly.

DESCRIPTION OF SYMBOLS 1 ...

Gas breaker

2, 4 ... Fixed contact part 3 ... Movable contact part 7a, 7b ... Lead-out conductor 8 ... Sealed container 9 ... Drive device 21 ... Arc Contact (fixed side)
22 ··· Fixed electric contact 23 ··· Insulating nozzle 23a · · · Throat section 24 · · ·

Exhaust cylinder

24a, 24b, 24c · · · Exhaust port 31 · · · Trigger electrode 32 · · · · · · · 通電 moveable contact 33 ... Piston 33a ... Piston support 33t ... Tapered portion 36 ... Compression chamber 37 ... Insulation rod 38 ... Accumulation chamber 41 ... Arc contactor (movable side)
42 ... cylinder 42a ... insertion hole 42b ... through hole 42c ... intake hole 42d ... intake valve 42e ... check valve 42g ... guide 42m ... shaft 42n ... Valve head 42s ... spring 43 ... support

Claims

A first arc contact electrically connected to a first lead conductor connected to the power system;
A second arc contact electrically connected to the second lead conductor;
It is disposed movably between the first arc contact and the second arc contact, and in the first half of the current interruption time, an arc is generated between the first arc contact and the first arc contact as it moves. Fired,
A trigger electrode for igniting the arc to the second arc contact according to the movement in the second half of the current interruption;
A compression chamber for pressurizing the arc-extinguishing gas,
An accumulator chamber which communicates with the compression chamber via a through hole, is formed by the trigger electrode and the second arc contact, and stores an arc-extinguishing gas pressurized in the compression chamber;
Have
In the first half when the current is shut off, the pressure accumulation chamber is sealed by the trigger electrode and the second arc contact, and in the second half when the current is shut off, the pressure accumulation chamber is closed by the trigger electrode and the second arc. A gas circuit breaker which is opened by separation of contacts, and an arc extinguishing gas is jetted from an opening of the second arc contact to extinguish the arc,
A gas circuit breaker having a check valve for preventing inflow of arc-extinguishing gas from the pressure accumulation chamber to the compression chamber in the through hole communicating the pressure accumulation chamber and the compression chamber.
The check valve is
The valve is opened in the first half when the current is interrupted, and the arc-extinguishing gas pressurized in the compression chamber is made to flow into the pressure accumulation chamber,
In the second half when the current is shut off, the flow of arc-extinguishing gas from the pressure accumulation chamber to the compression chamber is prevented.
The gas circuit breaker according to claim 1.
The check valve is connected to a spring that applies a force in a direction in which the check valve closes.
The sum of the force of the spring and the force acting in the direction to close the check valve by the arc-extinguishing gas inside the pressure accumulation chamber opens the check valve by the arc-extinguishing gas inside the compression chamber The check valve closes when the force acting on the
The gas circuit breaker according to claim 1 or 2.
The compression chamber has a piston for compressing an arc-extinguishing gas,
The check valve comes in contact with the piston and closes in the second half when the current is shut off.
The gas circuit breaker according to any one of claims 1 to 3.
The piston has a tapered portion in contact with the check valve, and when the valve is closed, the tapered portion contacts the check valve.
The gas circuit breaker according to claim 4.
The tapered portion of the piston is formed at an angle such that the inner diameter side is in contact with the check valve and the outer diameter side is not in close contact with the check valve.
The gas circuit breaker according to claim 5.