JP2017097961A - Gas Circuit Breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas circuit breaker capable of obtaining a sufficient interelectrode insulation strength, even if a decomposition gas or a decomposition product is generated, even without enlarging a pressure accumulation chamber.SOLUTION: The gas circuit breaker comprises: a sealed container filled with an arc-extinguishing gas; an opposite arc contactor and a movable arc contactor which are disposed oppositely within the sealed container and are brought into contact with or separated from each other in the case of power-off or power-on, and in which arch discharge is generated in the process of separation; a pressure accumulation chamber which blows the pressure-accumulated arc-extinguishing gas to the arc discharge; an opposite-side support part supporting the opposite arc contactor; a movable-side support part supporting the movable arc contactor; and an insulation cylinder 6 which connects the opposite-side support part and the movable-side support part and of which the internal space is communicated with an arc space where the arc discharge is generated. The insulation cylinder 6 includes: an insulation member 6a which is cylindrical and has a support strength; and an insulation member 6b which has decomposition gas resistance and decomposition product resistance, and the insulation member 6b is provided on an inner face of the insulation member 6a.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a gas circuit breaker that performs current interruption in a power system.

Currently, in the electric power system high voltage large capacity, gas-insulated switchgear apparatus with insulation and arc-extinguishing medium SF ₆ gas is widely used. As a main device constituting the gas insulated switchgear, there is a gas circuit breaker filled with SF ₆ gas. This gas circuit breaker is a power device capable of quickly interrupting a fault current in the power system. The gas circuit breaker mechanically disconnects the contact during the disconnection process, and extinguishes arc discharge generated by the disconnection by blowing an insulating and arc-extinguishing medium.

  The type of gas circuit breaker as described above is now widely used as a puffer type. The puffer-type gas circuit breaker is arranged in a sealed container filled with an arc extinguishing gas, with a fixed arc contact and a fixed energizing contact, and a movable arc contact and a movable energizing contact arranged to face each other. Is brought into contact or separated by a mechanical driving force to conduct or cut off the current.

  In this gas circuit breaker, the volume decreases with the separation of the contacts, and the pressure accumulating chamber in which the arc extinguishing gas is accumulated and the arc contacts are disposed so as to surround the pressure accumulating chamber, and the pressure is accumulated in the pressure accumulating chamber. An insulating nozzle is provided for inducing arc-extinguishing gas to arc discharge.

  In the interruption process, the fixed arc contact and the movable arc contact are separated from each other, so that arc discharge occurs between the arc contacts. The arc extinguishing gas, which has been sufficiently accumulated in the accumulator chamber with the separation of the contacts, is strongly blown to the arc discharge through the insulation nozzle, thereby restoring the insulation performance of both arc contacts and reducing the arc discharge. The arc is extinguished at the current zero point to complete the current interruption.

Japanese Patent Publication No. 7-97466

  In the conventional gas circuit breaker as described above, an insulating cylinder that connects a fixed contact portion provided with a fixed arc contact and a movable contact portion provided with a movable arc contact and insulates these contact portions. Is provided. The insulating cylinder is provided so that its internal space communicates with an arc space where arc discharge occurs.

  When a high-current arc of several kA to several tens of kA order is interrupted, such as when a fault current is interrupted, the arc extinguishing gas is decomposed, and the material of the fixed and movable arc contacts and the insulating nozzle is extinguished. It may ablate in the gas. For this reason, after the failure current is interrupted, the arc-extinguishing gas decomposition gas and various decomposition products solidified due to the temperature decrease exist in the sealed container.

  Therefore, when the inner surface of the insulating cylinder in the hermetic container is exposed to such a decomposition gas, the surface may change in the short term or in the long term, and the dielectric strength may decrease. Moreover, when a solid decomposition product accumulates on the inner surface, in addition to the deterioration of the insulating cylinder, the surface resistance may decrease and the dielectric strength may decrease.

  Therefore, in general, even if there is a decrease in insulation strength due to cracked gas or decomposition products, the insulating cylinder is configured with sufficient tolerance by taking an insulating distance such as increasing the length of the insulating cylinder. However, there arises a problem that the pressure accumulating chamber is enlarged as the insulating cylinder is enlarged.

  The gas circuit breaker according to the present embodiment has been made to solve the above-described problems, and even if there is no generation of cracked gas and cracked products without increasing the pressure accumulating chamber, it is sufficient. It aims at providing the gas circuit breaker which can acquire the insulation strength between.

  In order to achieve the above object, the gas circuit breaker according to the present embodiment is a gas circuit breaker that switches between interruption and supply of current, and is opposed to the hermetic container filled with an arc extinguishing gas, Arranged, opposed arc contacts and movable arc contacts that are in contact with or separated from each other when interrupted or turned on, and arc discharge is generated in the process of opening, and the arc extinguishing gas accumulated with respect to the arc discharge A pressure accumulating chamber, a facing support part that supports the counter arc contact, a movable support part that supports the movable arc contact, and a connection between the facing support part and the movable support part. And an insulating cylinder communicating with the arc space where the arc discharge is generated, the insulating cylinder being cylindrical and having a supporting strength, a decomposition gas resistance, and a decomposition resistant generation Second perfection with physical properties And a member, said second insulating member is provided on the inner surface of the first insulating member, and wherein.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the whole structure of the gas circuit breaker which concerns on 1st Embodiment, Comprising: (a) is sectional drawing of the gas circuit breaker which shows a normal closing (electric current supply) state, (b) is opening. It is sectional drawing of the gas circuit breaker which shows the state of (in current interruption operation | movement). It is an expanded sectional view of the insulating cylinder concerning a 1st embodiment. It is an expanded sectional view of the insulating cylinder which concerns on 2nd Embodiment.

[1. First Embodiment]
[1-1. overall structure]
First, the whole structure of the gas circuit breaker of this embodiment is demonstrated, referring drawings. FIG. 1 is a cross-sectional view showing the overall configuration of the gas circuit breaker of the present embodiment. FIG. 1 (a) shows a normally closed (current-carrying) state, and FIG. It shows the state of current interruption operation).

  The gas circuit breaker according to the present embodiment is provided with a facing contact portion 10 and a movable contact portion 20 facing each other between a sealed container 1 made of a grounded metal and a conductor 7a and a conductor 7b drawn from the outside of the sealed container 1. . The opposed contact portion 10 is fixed to the opposed side support portion 13 connected to the conductor 7a. The movable contact portion 20 is fitted in the movable side support portion 33 so as to be slidable in a direction in which the movable contact portion 20 contacts and separates from the opposing contact portion 10. An energizing contact 28 is provided on the inner wall surface of the movable side support portion 33, and the movable contact portion 20 is slidably in contact with the contact 28. The conductor 7 b is connected to the movable side support portion 33. The conductor 7a, the opposed side support portion 13 and the opposed contact portion 10 are connected in series to form an electric circuit on one side, and the conductor 7b, the movable side support portion 33 and the movable contact portion 20 are connected in series to form the other electric circuit. Is done.

  This gas circuit breaker opens and closes the electric paths on the conductor 7a side and the conductor 7b side by bringing the movable contact portion 20 into and out of contact with the opposing contact portion 10, thereby conducting and blocking current. The movable contact portion 20 is connected to an insulating rod 27, and the insulating rod 27 is connected to a mechanism portion (not shown) that is a power source such as a spring type or a hydraulic type. The movable contact portion 20 contacts and separates from the opposing contact portion 10 by pushing and pulling the insulating rod 27 by the mechanism portion.

  In the current interruption process, an arc discharge 9 is generated between the opposed contact portion 10 and the movable contact portion 20. The sealed container 7 is filled with an arc extinguishing gas. The movable contact portion 20 is provided with a pressure accumulating chamber 25 that reduces the volume in conjunction with the separation from the opposing contact portion 10. The pressure accumulating chamber 25 discharges the arc extinguishing gas toward the pressure accumulating and arc discharge 9 by reducing the volume, and extinguishes the arc discharge 9 at the current zero point.

The arc extinguishing gas is a gas excellent in arc extinguishing performance and insulation performance, and examples thereof include sulfur hexafluoride gas (SF ₆ gas). However, SF ₆ gas is said to have a global warming effect 23,900 times that of carbon dioxide gas. From the viewpoint of environmental conservation, SF ₆ gas may be a gas having a smaller global warming potential than SF ₆ gas. good. Examples of the gas having a small global warming potential include air, carbon dioxide, oxygen, nitrogen, or a mixed gas thereof.

  Such a gas circuit breaker is assembled by members mainly made of a cylinder, and the respective members are arranged in the sealed container 7 with their central axes aligned. Hereinafter, in order to explain the positional relationship and direction of each member, the direction toward the movable contact portion 20 in each member of the opposed contact portion 10 and the opposed side support portion 13 is referred to as a movable side, and the opposite is referred to as an anti-movable side. In each member of the movable contact portion 20, the direction toward the opposing contact portion 10 is referred to as an opposite side, and the opposite is referred to as an opposite side.

[1-2. Detailed configuration]
First, the opposed side support portion 13 and the movable side support portion 33 are fixed in the sealed container 1 so as to face each other. The opposite side support portion 13 is a hollow cylindrical conductor having both ends opened, and fixes the opposite contact portion 10. The movable side support portion 33 is a cup-shaped conductor having an opening on the opposite side, and the movable contact portion 20 is inserted through the opening on the opposite side, and is slidably supported on the energizing contact 28 provided on the inner surface. The movable side support portion 33 is insulated and supported by an insulation support base 34 erected on the inner wall of the sealed container 1.

  The opposing side support portion 13 and the movable side support portion 33 are spaced apart from each other in the sealed container 1 with their openings facing each other. Openings facing each other of the opposed side support portion 13 and the movable side support portion 33 are formed in a flange shape, and the insulating cylinder 6 is joined between the opposed side support portion 13 and the movable side support portion 33. .

  The insulating cylinder 6 is made of a cylindrical insulator, and the diameter thereof is the same as that of the opposing side support portion 13 and the movable side support portion 33, and connects the opposing side support portion 13 and the movable side support portion 33. . The insulating cylinder 6 insulates the space between the opposed side support portion 13 and the movable side support portion 33 and the inner wall surface of the sealed container 1, and extinguishes the arc discharge 9 together with the opposed side support portion 13 and the movable side support portion 33. An arc extinguishing chamber is formed. That is, the internal space of the insulating cylinder 6 communicates with the arc space where the arc discharge 9 is generated.

  FIG. 2 is an enlarged cross-sectional view of the insulating cylinder 6. As shown in FIG. 2, the insulating cylinder 6 includes an insulating member 6a having a cylindrical shape and supporting strength, and an insulating member 6b having decomposition gas resistance and decomposition product resistance. The insulating member 6a is made of, for example, FRP or epoxy resin, and a hollow cylindrical shape is widely used. FRP forms a cylindrical shape by winding an FRP sheet around a rod called a mandrel, whereas an epoxy resin molds a cylindrical shape by pouring into a so-called mold. An epoxy resin containing alumina or silica may be used to increase mechanical strength.

  The insulating member 6b is provided on the inner surface of the insulating member 6a, and the cylindrical insulating member 6b is formed integrally with the insulating member 6a or is provided as a coating layer on the inner surface of the insulating member 6a. According to integral molding, since it can manufacture by inject | pouring material into a metal mold | die, manufacture becomes simple. In the case of providing as a coating layer, a separate device such as a mold is unnecessary, and it can be easily manufactured. The insulating member 6a and the insulating member 6b may be separately formed into a cylindrical shape, and the insulating tube 6 may be configured as a double tube by an adhesive or the like. The insulating cylinder 6 may be configured as a triple cylinder by overlapping the insulating member 6a or the insulating member 6b. The insulating member 6b has higher decomposition gas resistance and decomposition product resistance than the insulating member 6a, and is made of, for example, an epoxy resin. However, the insulating member 6b is not limited to this, and the insulating member 6b may be made of a heat-resistant resin such as a fluororesin, polyimide, or PEEK. Further, when the insulating member 6b is a coating layer, a fluororesin system may be used. The insulating member 6b has the decomposition gas resistance and the decomposition resistance product property, but may also have the insulating member 6a. In this case, the insulating member 6b has a higher decomposition gas resistance and decomposition product resistance than the insulating member 6a.

  The opposing contact portion 10 includes an opposing contact 11 and an opposing energizing contact 12. The movable contact portion 20 includes a movable contact 21, a movable energizing contact 22, an insulating nozzle 23, a movable cylinder 24, a pressure accumulation chamber 25, and an operation rod 26.

  The opposed energizing contact 12 and the movable energizing contact 22 are cylindrical conductors each having an open end face, and are disposed on the same axis with the openings facing each other. The opening edge of the opposed energizing contact 12 bulges inside, and the inner diameter of the opening edge portion and the outer diameter of the movable energizing contact 22 are the same.

  The opposed energizing contact 12 is fixed to the movable support 13. The movable energizing contact 22 is movable with respect to the opposing energizing contact 12, and the movable energizing contact 22 is inserted into the opening of the opposing energizing contact 12, thereby moving the inner surface of the opposing energizing contact 12. It will be in the state which can contact with the outer surface of the electricity supply contact 22 and can be electrically connected.

  The counter arc contact 11 is a solid cylindrical conductor whose one end is rounded. The counter arc contact 11 is fixedly supported via a support portion 14 provided so as to protrude from the inner wall surface of the counter side support portion 13 to the inside thereof.

  The movable arc contactor 21 is a conductor having a cylindrical shape with both ends opened. In the current interruption process, the movable arc contact 21 is separated from the opposed arc contact 11, and an arc space in which arc discharge 9 is generated is formed between both the contacts 11 and 21.

  The opening edge of the movable arc contact 21 bulges inside, and its inner diameter matches the outer diameter of the counter arc contact 11. The movable arc contact 21 is movable with respect to the opposed arc contact 11. When the opposed arc contact 11 is inserted into the opening of the movable arc contact 21, both the contacts 11, 21 are brought into contact with each other, and are electrically connected. It will be ready.

  The tip of the movable arc contact 21 may be divided in the circumferential direction to form a finger electrode. In that case, the movable arc contact 21 has flexibility, and the inner diameter of the opening edge of the movable arc contact 21 is slightly smaller than the outer diameter of the opposed arc contact 11 and is narrowed. When the opposing arc contact 11 is inserted into the opening of the movable arc contact 21, both the contacts 11 and 21 come into contact with each other and become conductive.

  The movement of the movable arc contact 21 with respect to the counter arc contact 11 is caused by an operating rod 26 fixedly supported by the movable arc contact 21. The operation rod 26 is a hollow cylinder having an opening on the opposite side, and is disposed on the central axis. The operation rod 26 is connected to a mechanism unit (not shown) connected to the hermetic container 1 via an insulation rod 27 that is a solid solid cylinder having insulating properties. By being pushed and pulled, the entire movable contact portion 2 moves to the opposite side and the opposite side.

  In the opening on the opposite side of the operation rod 26, a movable arc contact 21 having the same diameter is erected toward the opposite side. A pressure accumulation chamber 25, which is a Baumkuchen-shaped space for blowing the arc-extinguishing gas accumulated with respect to the arc discharge 9, is provided around the circumference of the operation rod 26. That is, the pressure accumulating chamber 25 includes an operating rod 26, a cylinder 24 that is linked to the operating rod 26, and a piston 31 that does not move.

  The cylinder 24 is a conductor having a bottomed cup shape, and extends toward the opposite side along the central axis so that the bottomed end surface faces the opposite side and the side surface surrounds the operation rod 26. The bottomed portion of the cylinder 24 is provided with a ring-shaped communication hole 24 a that communicates the inside and outside of the cylinder 24. The communication hole 24 a is slightly larger than the diameter of the operation rod 26. The cylinder 24 is connected so that the communication hole 24 a and the operation rod 26 are coaxial, and is flush with the opposite end surface of the operation rod 26.

  The piston 31 is a donut-shaped disk whose center is open. A piston support 31a extends from the inner surface of the movable support 33, and the position of the piston 31 is fixed by the piston support 31a. The piston 31 is disposed facing the bottom end surface of the cylinder 24 away from the opposite side. The outer shape of the piston 31 substantially matches the inner diameter of the cylinder 24 and is fitted into the cylinder 24. The opening diameter of the piston 31 substantially matches the outer diameter of the operation rod 26, and the operation rod 26 is slidably inserted into the opening of the piston 31.

  The pressure accumulating chamber 25 has a space defined by the outer peripheral surface of the operating rod 26, the inner peripheral surface of the cylinder 24, and the piston 31. The volume of the pressure accumulating chamber 25 is variable when the bottomed end surface of the cylinder 24 approaches or separates from the piston 31 in conjunction with the movement of the operation rod 26. The cylinder 24 reduces the volume of the pressure accumulating chamber 25 by the approach of the bottomed end surface to the piston 31. Then, the arc extinguishing gas in the pressure accumulating chamber 25 is compressed and accumulated, and the arc extinguishing gas is ejected toward the arc discharge 9 from the communication hole 24a.

  On the bottomed end surface of the cylinder 24, an insulating nozzle 23 is provided so as to cover the movable arc contact 21. The insulating nozzle 23 is provided so as to extend the cylinder from the outer periphery of the communication hole 24 a of the cylinder 24 to the opposite side, and its internal space communicates with the pressure accumulation chamber 25. That is, the insulating nozzle 23 is a rectifying means for guiding the arc extinguishing gas accumulated in the pressure accumulating chamber 25 to the arc space through the communication hole 24a. The insulating nozzle 23 is a Laval nozzle provided with a throat 23a which is the smallest inner diameter portion, and has an internal space which is reduced in diameter from the bottomed end surface of the cylinder 24 to the throat 23a and expanded from the throat 23a to the opposite side.

[1-3. Operation]
Operation | movement of the gas circuit breaker of this embodiment is demonstrated. In the energized state, as shown in FIG. 1A, the conductor 7a, the opposed side support portion 13, the opposed energized contactor 12, the movable energized contactor 22, the cylinder 24, the energized contactor 28, the movable side supporter 33, and the conductor. 7b is electrically connected to form an electric furnace. In the energized state, the current flows from the conductor 7a or the conductor 7b to the gas circuit breaker, and flows out from the other conductor 7b or the conductor 7a to the outside of the gas circuit breaker via the opposed contact portion 10 and the movable contact portion 20.

  When interrupting an accident current or the like, the gas circuit breaker opens the movable contact portion 20 with respect to the opposing contact portion 10 to interrupt the current. Specifically, the operating rod 26 receives the operating force of the operating portion and moves along the central axis in the opposite direction to the opposed contact portion 10. The movable contact portion 20 is dragged by the operating rod 26 and moves away from the opposed contact portion 10, and the opposed energized contact 12 and the movable energized contact 22 are separated.

  In conjunction with the movement of the operating rod 26, the bottom end surface of the cylinder 24 approaches the piston 31 whose position is fixed. Therefore, the volume of the pressure accumulating chamber 25 decreases, and the arc extinguishing gas in the pressure accumulating chamber 25 is accumulated according to Boyle's law.

  When the interruption operation further proceeds and the movable arc contact 21 is separated from the opposed arc contact 11, an arc discharge 9 is generated between the movable end of the opposed arc contact 11 and the movable arc contact 21. Arc. When the interruption operation further proceeds, the distance between the counter arc contact 11 and the movable arc contact 21 is sufficiently wide, and the pressure accumulation chamber 25 is sufficiently accumulated, the arc extinguishing gas in the pressure accumulation chamber 25 is communicated with the communication hole 24a. It passes through the insulating nozzle 23 and passes through.

  The arc extinguishing gas that has become a jet is guided toward the arc discharge 9 using the gas flow path between the insulating nozzle 23 and the movable arc contact 21, and is strongly blown onto the arc discharge 9. When the arc discharge 9 reaches the current zero point, the arc discharge 9 is extinguished in combination with the blowing of a strong arc extinguishing gas. Thereby, the current interruption of the gas circuit breaker is completed.

  In the process of the current interruption operation, the arc extinguishing gas blown to the arc discharge 9 is discharged separately to the movable contact portion 20 side and the opposed contact portion 10 side. Specifically, the arc-extinguishing gas on the side of the opposing contact portion 10 is a space surrounded by the outer peripheral surface of the opposing arc contact 11 and the inner peripheral surface of the opposing energizing contact 12 from the space where the arc discharge 9 is generated. As a result, the air is exhausted into the hermetic container 1 using the internal space of the opposed support 13 as an exhaust path.

  On the movable contact portion 20 side, the arc extinguishing gas enters the movable arc contact 21 from the space where the arc discharge 9 is generated and enters the operation rod 26. In the operation rod 26, the arc extinguishing gas reaches a through hole 26a provided on the side surface of the operation rod 26 on the insulating rod 27 side, and the movable side support outside the operation rod 26 is provided through the through hole 26a. It is discharged into the internal space of the portion 33. A through hole 33a is also provided on the side peripheral surface of the movable support portion 33. The through hole 33a passes through the through hole 33a and reaches the inside of the sealed container 1 to complete exhaust.

[1-4. Action]
When a high-current arc on the order of several kA to several tens of kA is interrupted, the arc extinguishing gas is decomposed, and the material of the insulating nozzle 23 and the material of the opposed arc contactor 11 and the movable arc contactor 21 are in the arc extinguishing gas. It will ablate. For this reason, after the failure current is interrupted, the arc-extinguishing gas decomposition gas and various decomposition products solidified due to a decrease in temperature exist in the sealed container 1. The insulating cylinder 6 is exposed to these decomposition gases and decomposition products in the short term and in the long term.

  In particular, since the insulating cylinder 6 is provided so as to cover an arc space where a large amount of cracked gas and cracked products are generated, its inner surface is easily exposed to these cracked gases and cracked products. Since the insulating member 6a is configured as a support member having mechanical strength that supports the opposing contact portion 10, FRP or epoxy resin is often used. In the case of such a material, the insulation strength may decrease due to decomposition gas or decomposition products. In this embodiment, since the insulating member 6b having the decomposition gas resistance and the decomposition product property is provided on the inner surface of the insulating member 6a, the impulse voltage at the time of lightning strike is applied in the interruption state. However, sufficient insulation strength between the electrodes can be obtained.

[1-5. effect]
(1) The gas circuit breaker of the present embodiment is a gas circuit breaker that switches between interruption and injection of current, and is disposed oppositely in the hermetic container 1 filled with the arc-extinguishing gas, and shuts off or The opposed arc contact 11 and the movable arc contact 21 that are brought into contact with or separated from each other at the time of charging, and the arc discharge 9 is generated in the course of the separation, and the accumulated pressure for blowing the arc extinguishing gas accumulated on the arc discharge 9 The chamber 25, the opposed support 13 that supports the opposed arc contact 11, the movable support 33 that supports the movable arc contact 21, and the opposed support 13 and the movable support 33 are connected to each other. In addition, the inner space includes an insulating cylinder 6 communicating with the arc space where the arc discharge 9 is generated. The insulating cylinder 6 includes a first insulating member 6a having a cylindrical shape and supporting strength, and a second insulating member 6b having decomposition gas resistance and decomposition product properties. The second insulating member 6b includes: It is provided on the inner surface of the first insulating member 6a.

  Thereby, even if the inner surface of the insulating cylinder 6 is exposed to the decomposition gas and the decomposition products are likely to accumulate, it is possible to suppress a decrease in the insulating strength of the insulating cylinder 6 without enlarging the pressure accumulating chamber 25. Sufficient insulation strength between the electrodes can be obtained.

(2) The first insulating member 6a and the second insulating member 6b are integrally molded. Thereby, since it can manufacture by inject | pouring material into a metal mold | die, manufacture becomes easy.

(3) The second insulating member 6b is provided as a coating layer of the first insulating member 6a. Thereby, the insulation strength of the insulating cylinder 6 can be simply increased without requiring a separate device.

[2. Second Embodiment]
A second embodiment will be described with reference to FIG. The basic configuration of the second embodiment is the same as that of the first embodiment. Only points different from the first embodiment will be described, and the same parts as those of the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

  FIG. 3 is an enlarged cross-sectional view of the insulating cylinder 6 according to the second embodiment. The insulating cylinder 6 according to the second embodiment is that the insulating member 6b is provided not only on the inner surface but also on the outer surface of the insulating member 6a. The thickness of the insulating member 6b provided on the outer surface may be the same as or different from the thickness of the insulating member 6b provided on the inner surface.

  Further, since the cracked gas is heavier than the cracked product, the cracked gas is more easily exhausted into the sealed container 1. Therefore, the outer surface of the insulating cylinder 6 is more easily exposed to the decomposition gas than the decomposition product. Therefore, the insulating member 6b provided on the outer surface of the insulating member 6a may be configured to have a decomposition gas resistance higher than the decomposition product resistance. For example, when such a material is used or a material having a decomposition-resistant gas property and a material having a decomposition-resistant product property are mixed, the ratio of the material having the decomposition-resistant gas property is increased. .

  In the present embodiment, the insulating member 6b is provided not only on the inner surface of the insulating member 6a but also on the outer surface. Thereby, since the fall of an insulation strength is also suppressed for the outer surface of the insulating cylinder 6, even if it does not enlarge the pressure accumulation chamber 25, sufficient insulation strength between poles can be obtained.

[3. Third Embodiment]
A third embodiment will be described. The basic configuration of the third embodiment is the same as that of the second embodiment. Only differences from the second embodiment will be described, and the same parts are denoted by the same reference numerals and detailed description thereof will be omitted.

  In the third embodiment, the insulating member 6b is provided as a coating layer on the inner surface and the outer surface of the insulating member 6a, and the dielectric constant of the insulating member 6b is 50% to 150% of the dielectric constant of the insulating member 6a. If the dielectric constant deviates from this range, charges such as polarization charges may be generated at the interface between the insulating member 6a and the insulating member 6b to affect the insulation strength. However, as in the above range, it becomes the core. By making the values of the dielectric constants of the insulating member 6a and the insulating member 6b provided on the surface close to each other, it is possible to avoid the influence on the insulation strength due to the generation of electric charges at the interface between the insulating member 6a and the insulating member 6b. .

[4. Fourth Embodiment]
A fourth embodiment will be described. The basic configuration of the fourth embodiment is the same as that of the second embodiment. Only differences from the second embodiment will be described, and the same parts are denoted by the same reference numerals and detailed description thereof will be omitted.

  The thermal expansion coefficient of the insulating member 6b is 75% to 125% of the thermal expansion coefficient of the insulating member 6a serving as the core. If it deviates from this range, there is a possibility that the dimensional difference between the members 6a and 6b becomes large due to the difference in thermal expansion, and the insulating member 6b peels off from the surface of the insulating member 6a, so that the insulation strength decreases. If it exists, it can suppress that the insulating member 6b peels from the surface of the insulating member 6a, and insulation strength falls.

  The thermal expansion coefficient of the insulating member 6b provided on the inner surface of the insulating member 6a is preferably 75% to 100% of the thermal expansion coefficient of the insulating member 6a serving as the core. That is, the inner surface of the insulating member 6a is exposed to a high-temperature gas heated by the arc discharge 9, but by setting this range, peeling due to a change in the dimensional difference between the members 6a and 6b is suppressed by the difference in thermal expansion. In addition, a decrease in insulation strength can be suppressed.

[5. Other Embodiments]
In the present specification, a plurality of embodiments according to the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. Specifically, a combination of all or any of the first to fourth embodiments is also included. The above 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 equivalents thereof as well as included in the scope and gist of the invention.

(1) In the first to fourth embodiments, the opposed contact portion 10 is fixed and only the movable contact portion 20 is moved in the axial direction, but the movable contact portion 20 is moved with respect to the opposed contact portion 10. The counter contact portion 10 may also be moved in the axial direction so as to move relatively, so that a so-called dual motion mechanism that improves the relative opening speed may be used.

(2) In the first to fourth embodiments, the gas circuit breaker having the pressure accumulating chamber 25 by mechanical action is shown. However, in the present invention, the heat energy action of the pressure accumulating chamber 25 by mechanical action and the arc discharge 9 is shown. It is applicable also to the gas circuit breaker which has the pressure accumulation space by.

DESCRIPTION OF SYMBOLS 1 Airtight container 7a, 7b Conductor 10 Opposing contact part 11 Opposing arc contact 12 Opposing energizing contact 13 Opposing side support part 14 Supporting part 20 Movable contact part 21 Movable arc contact 22 Movable energizing contact 23 Insulating nozzle 23 Throat 24 Cylinder 24a Communicating hole 25 Pressure accumulating chamber 26 Operating rod 27 Insulating rod 28 Energizing contact 31 Piston 31a Piston support 33 Movable support 33a Through hole 6 Insulating cylinder 6a, 6b Insulating member 7a Conductor 7b Conductor 9 Arc

Claims (7)

A gas circuit breaker that switches between cutting off and turning on current,
A sealed container filled with arc-extinguishing gas;
An opposed arc contact and a movable arc contact, which are opposed to each other in the closed container, contact or separate from each other at the time of shut-off or charging, and arc discharge is generated in the process of opening;
A pressure accumulating chamber that blows the arc extinguishing gas accumulated against the arc discharge;
An opposing side support for supporting the opposing arc contact;
A movable side support for supporting the movable arc contact;
An insulating cylinder that connects between the opposed side support part and the movable side support part, and an internal space communicates with the arc space where the arc discharge occurs,
With
The insulating cylinder includes a first insulating member having a cylindrical shape and supporting strength, and a second insulating member having decomposition gas resistance and decomposition product resistance,
The second insulating member is provided on an inner surface of the first insulating member;
A gas circuit breaker characterized by The second insulating member is provided on an inner surface and an outer surface of the first insulating member;
The gas circuit breaker according to claim 1. The first insulating member and the second insulating member are integrally molded;
The gas circuit breaker according to claim 1 or 2. The second insulating member is a coating layer of the first insulating member;
The gas circuit breaker according to any one of claims 1 to 3. The dielectric constant of the second insulating member is 50% to 150% of the dielectric constant of the first insulating member;
The gas circuit breaker according to any one of claims 1 to 4. The thermal expansion coefficient of the second insulating member is 75% to 125% of the thermal expansion coefficient of the first insulating member;
The gas circuit breaker according to any one of claims 1 to 5. The second insulating member provided on the inner surface of the first insulating member has a thermal expansion coefficient of 75% to 100% of the thermal expansion coefficient of the first insulating member;
The gas circuit breaker according to any one of claims 1 to 6.

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