JP2015041504A - Gas circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas circuit breaker having a sufficient cutoff performance without increasing the opening speed of the electrodes while reducing damages on the tip on which a high electric field is created due to collision with an arc contact at turning ON operation.SOLUTION: An opposite arc contact 11 of an opposite contact section 10 includes a fixed cylindrical part 11a and a movable tip 11b. The fixed cylindrical part 11a has an opening on the tip oriented to a movable contact part 20. The movable tip 11b extends from the opening of the fixed cylindrical part 11a toward the movable contact part 20 so as to contact therewith. The fixed cylindrical part 11a has a sliding part 11c which is the inner periphery of the opening to support the movable tip 11b slidably in a protruding/retreating direction with respect to the fixed cylindrical part 11a.

Description

  Embodiments of the present invention relate to a gas circuit breaker that switches between current interruption and input in a power system.

  In an electric power system, a gas circuit breaker is used when it is necessary to interrupt an excessive accident current, a small advance current, a delayed load current such as a reactor cutoff, or an extremely small accident current. The gas circuit breaker mechanically disconnects the contactor during the disconnection process, and extinguishes the arc discharge generated during the disconnection process by blowing arc-extinguishing gas.

  As the above-described gas circuit breaker, a type called a puffer type is currently widely used (see, for example, Patent Document 1). The puffer-type gas circuit breaker is arranged in an airtight container filled with an arc extinguishing gas, with an opposed arc contact and an opposed energized contact, and a movable arc contact and a movable energized contact, respectively, facing 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 space in which the arc-extinguishing gas is accumulated and the arc-contacting properties of the pressure-accumulating space are arranged so as to surround both arc contacts. An insulating nozzle is provided to guide the gas to the arc. In the interruption process, an arc is generated between the arc contacts because the opposed arc contact and the movable arc contact are separated. The arc-extinguishing gas, which is sufficiently accumulated in the accumulator space with the separation of the contacts, is strongly blown to the arc through the insulation nozzle, thereby restoring the insulation performance of both arc contacts, extinguishing the arc, Complete the current interruption.

  As a gas circuit breaker that can effectively cut off from a small current to a large current, a type called a serial puffer type is widely used (see, for example, Patent Document 2). In this gas circuit breaker, the accumulator space is divided into two chambers having different pressure increasing mechanisms in order to improve the shut-off performance without increasing the driving energy. That is, the gas circuit breaker has both a heat puffer chamber and a mechanical puffer chamber, and pressurizes the arc-extinguishing gas by using both the heating pressurization action and the mechanical compression action to generate a powerful jet.

  When a large current is interrupted, the arc discharge is very hot, so that the surrounding arc extinguishing gas is heated, and the thermal puffer chamber is heated by the thermal expansion of the arc extinguishing gas and the flow into the thermal puffer chamber. Boosts significantly. The pressure in the heat puffer chamber generates a sufficient arc extinguishing gas blowing force to extinguish the arc discharge.

  On the other hand, when the small current is interrupted, the self pressure boosting action due to the arc discharge is small, and therefore the pressure increase in the heat puffer chamber due to this action cannot be expected. In such a case, in the serial puffer type gas circuit breaker, since the arc extinguishing gas can be fed from the mechanical puffer chamber to the heat puffer chamber, the blowing pressure for cutting off the small current can be secured.

  Here, in the case of a large current arc on the order of several kA, such as when an accident current is interrupted, the distance between both arc contacts is sufficiently wide to form an appropriate flow path, and sufficient blowing pressure is applied to the pressure accumulation space. Unless the pressure is accumulated, the arc is not extinguished even when the current zero point is reached.

  However, in the case of a small current arc of several hundreds A or less, such as an advanced small current interruption, the arc is easily extinguished when the current zero point is reached even immediately after the opening of both arc contacts. . As a result, depending on the current phase, the arc duration will be close to 0 indefinitely, the arc will extinguish immediately after the arc contacts are released, and the recovery voltage from the grid will be reduced with a very small distance between the arc contacts. It will be applied. When the re-ignition is caused between the arc contacts due to the recovery voltage, an overvoltage may occur. Re-ignition is a dielectric breakdown phenomenon that occurs after a period of one quarter or more after the current zero point has elapsed in the commercial frequency voltage.

  Since dielectric breakdown between arc contacts threatens the reliability of system equipment, gas circuit breakers are generally required to have rapid insulation recovery characteristics sufficient to avoid re-ignition. In order to meet the demand, generally, the electric field at the tip of the arc contactor is relaxed, or the speed at the time when both arc contacts are separated, that is, the opening speed is improved, and the rapid contact between the arc contacts is improved. It is necessary to ensure insulation recovery.

  However, if the speed is increased by increasing the operation force, the drive device becomes large, or the weight of the movable contact portion increases to increase the mechanical strength, and the drive energy must be increased. There was a problem.

  Therefore, a technology that connects the drive unit and the movable contact part via a fixed cam mechanism, drives the link connected to the movable contact part along the shape of the cam groove, and improves the speed after opening. Has been proposed (see, for example, Patent Document 3). In addition, by installing a rotating groove cam between the driving device and the movable contact portion, a technique for reducing the driving energy efficiently by reducing the moving distance between the movable portion on the driving device side and the movable contact portion is also proposed. (For example, see Patent Document 4).

Japanese Examined Patent Publication No. 7-109744 Japanese Examined Patent Publication No. 7-97466 JP 2004-55420 A JP 2002-208336 A

  Increasing the opening speed also increases the approach speed of both arc contacts at the time of charging. If it does so, the impact force by both arc contacts colliding at the time of injection will become large, and it will become easy to generate | occur | produce the damage of the front-end | tip part of an arc contact.

  When the tip of the arc contact that becomes a high electric field portion is damaged, the surface roughness and shape change, and the electric field becomes higher, which causes a problem that dielectric breakdown is likely to occur. Further, if the high-speed closing duty for performing the closing operation immediately after the current interruption is fulfilled, both arc contacts in a high temperature state collide with each other, so that the tip of the arc contact is further damaged.

  At present, there is no technique for suppressing damage to the tip due to the collision of both arc contacts in the closing operation. The gas circuit breaker according to the present embodiment is made to solve the above-described problems, and reduces damage to the tip portion that becomes a high electric field portion due to collision of both arc contacts during the charging operation, An object of the present invention is to provide a gas circuit breaker having a good breaking performance without increasing the opening speed.

  In order to achieve the above object, a gas circuit breaker according to the present embodiment is a gas circuit breaker that switches on or off of an electric current, and is opposed to a sealed container filled with an arc-extinguishing gas and the sealed container. A first contact portion and a second contact portion that are arranged and contact or separate from each other when current is applied or interrupted, and at least one of the first contact portion or the second contact portion is A fixed cylindrical portion having an opening at an end facing the other, a movable tip portion protruding from the opening and extending so as to be able to come into contact with the other, an inner edge of the opening, and the movable tip portion being the fixed cylindrical portion And a sliding portion that is slidably supported in the advancing and retracting direction.

It is sectional drawing which shows the whole structure of the gas circuit breaker which concerns on this embodiment, Comprising: It is sectional drawing of the gas circuit breaker which shows the electric current interruption state before injection | throwing-up. It is sectional drawing which shows the whole structure of the gas circuit breaker which concerns on this embodiment, Comprising: It is sectional drawing which shows the state in which the movable arc contactor collided with the movable front-end | tip part of the counter arc contactor in the initial stage of injection | throwing-in operation. It is sectional drawing which shows the whole structure of the gas circuit breaker which concerns on this embodiment, Comprising: It is sectional drawing which shows the state of injection | throwing-in operation completion. It is sectional drawing which shows the whole structure of the gas circuit breaker which concerns on the modification of this embodiment.

(Outline configuration)
Hereinafter, the gas circuit breaker of the present embodiment will be described with reference to FIGS. The gas circuit breaker contacts and separates the contacts that make up the electric circuit for turning on and off the current and extinguishes arc discharge generated between the contacts during the current interruption process by blowing arc-extinguishing gas. . The gas circuit breaker of this embodiment is a so-called series puffer type, and sprays arc-extinguishing gas on arc discharge by using both a mechanical compression action and a heating pressure raising action.

This gas circuit breaker has an airtight container (not shown). The sealed container is made of metal, insulator or the like and is grounded. The sealed container is filled with an arc extinguishing gas. The arc extinguishing gas is, for example, sulfur hexafluoride gas (SF ₆ gas), air, carbon dioxide, oxygen, nitrogen, or a mixed gas thereof, or other gas excellent in arc extinguishing performance and insulation performance.

  The contacts are roughly divided into an opposed contact portion 10 and a movable contact portion 20, and are accommodated in a sealed container. The opposed contact portion 10 and the movable contact portion 20 are composed of a plurality of members having a basic shape of a cylinder or a column, and all have a common central axis.

  The opposing contact portion 10 includes an opposing arc contact 11 and an opposing energizing contact 12. The movable contact portion 20 includes a movable arc contact 21 and a movable energizing contact 22. The opposing energizing contact 12 and the movable energizing contact 22 are opposed to each other, and switching on and off of the current is switched by contact and separation between them, and the opposing arc contact 11 and the movable arc contact 21 are opposed to each other to separate them. Undertakes arc discharge.

  The position of the opposed contact portion 10 is fixed in the sealed container, and the movable contact portion 20 is movable along the central axis in the direction of opening and contacting from the opposed contact portion 10. That is, the movable contact portion 20 includes an operating rod 25 that moves along the central axis by an operating force of a driving device (not shown). When the operating rod 25 pushes the movable contact portion 20 toward the opposing contact portion 10 side or pulls it away from the opposing contact portion 10 side, the movable contact portion 20 comes into contact with or separates from the opposing contact portion 10.

  The arc-extinguishing gas blowing using both the mechanical compression action and the heating pressurization action is achieved by the gas flow generating means. The gas flow generating means is a torus-shaped heat puffer chamber 30 provided so as to surround the body of the operation rod 25, the mechanical puffer chamber 31, and the insulating nozzle 23. The heat puffer chamber 30 and the mechanical puffer chamber 31 are connected in series along the operation rod 25.

  The volume of the mechanical puffer chamber 31 is variable in conjunction with the movement of the operation rod 25, the volume decreases in the process of interrupting the current, and the arc-extinguishing gas is supplied to the heat puffer chamber 30 as the internal space accumulates pressure. Although the heat puffer chamber 30 is invariable in volume, the pressure is increased by the heat energy of arc discharge, and the arc extinguishing gas supplied from the mechanical puffer chamber 31 is combined with the pressure increase to release the arc extinguishing gas to the outside. . The insulating nozzle 23 surrounds the communication hole 24a that connects the heat puffer chamber 30 and the outside and a space where arc discharge occurs, and guides the arc extinguishing gas released from the heat puffer chamber 30 to the arc discharge.

(Detailed configuration)
First, the counter arc contact 11 is a double-structured conductor having a rounded tip. The counter arc contact 11 is separated into a fixed cylindrical portion 11a of the outer shell and a movable tip portion 11b inside. The fixed cylindrical portion 11a is an internal hollow cylinder, has an opening on the end surface facing the movable arc contact 21, and is fixed in position in the sealed container. A disk-shaped fixed support 13 is fixed perpendicularly to the central axis in the sealed container, and the fixed cylindrical portion 11 a faces the movable arc contact 21 from the center of one surface of the fixed support 13. It extends.

  The movable front end portion 11b is a rod-shaped conductor having a rounded front end, a part including the rear end enters the hollow portion of the fixed cylindrical portion 11a, and the front end side protrudes from the opening of the fixed cylindrical portion 11a. Yes. The fixed cylindrical portion 11a has an opening inner edge as a sliding portion 11c, and the movable tip portion 11b is supported by the sliding portion 11c and is movable in the axial direction.

  That is, the sliding portion 11c is formed by the inner edge of the opening of the fixed cylindrical portion 11a bulging inward, and the bulging portion has a certain length in the axial direction and the inner diameter of the bulging portion. The outer diameter of the movable tip portion 11b coincides with the outer diameter. The sliding portion 11c is made of a material having conductivity and elasticity, and elastically deforms the movement of the movable tip portion 11b with respect to the fixed cylindrical portion 11a while maintaining conduction between the movable tip portion 11b and the fixed cylindrical portion 11a. Allow by.

  An elastic body 11d is accommodated in the hollow portion of the fixed cylindrical portion 11a. The elastic body 11d has one end connected to the fixed support 13 and the other end connected to the rear end of the movable tip portion 11b. The elastic body 11d is, for example, a compression spring, and absorbs the contact impact force from the movable arc contact 21 received by the movable tip portion 11b on the tip side during the charging process.

  However, on the rear end side of the movable tip portion 11b, a stopper 11e made of an impact buffering material is provided around the trunk located inside the fixed cylindrical portion 11a so as to protrude from the peripheral surface. Protrusion beyond a certain level is prevented.

  Next, the movable arc contact 21 is a conductor having an internal hollow cylindrical shape opened at both ends, and is disposed on the same axis with the movable tip 11b of the opposed arc contact 11 facing one opening. . The opening edge of the movable arc contact 21 bulges inside, and the inner diameter of the opening edge portion coincides with the outer diameter of the movable tip portion 11b. The movable arc contact 21 is fixed to the operation rod 25, and moves toward and away from the movable tip 11 b in conjunction with the movement of the operation rod 25, and the movable tip 11 b is inserted into the opening of the movable arc contact 21. As a result, the movable arc contact 21 and the counter arc contact 11 can be brought into conduction.

  The tip of the movable arc contact 21 may be formed as a finger-like electrode by being divided in the circumferential direction. In this case, the movable arc contact 21 has flexibility, and the movable arc contact The inner diameter of the opening edge 21 is narrowed slightly smaller than the outer diameter of the counter arc contact 11.

  The operation rod 25 is an internal hollow cylinder having an open end to which the movable arc contact 21 is fixed. The rear end is connected to the drive device and is pushed or pulled in the axial direction. The movable arc contact 21 and the operation rod 25 have the same diameter, and the movable arc contact 21 is erected with its peripheral edge aligned with the opening edge of the operation rod 25. In the middle of the operation rod 25, a tapered surface 25a sharpened toward the distal end side of the operation rod 25 is provided so as to stand up, and a communication hole 25b communicating with the outside of the operation rod 25 is formed in the vicinity of the tapered surface 25a. Yes. The communication hole 25b is formed behind a piston 27 described later.

  The heat puffer chamber 30 and the mechanical puffer chamber 31 are constituted by a cylinder 24, a piston 27, and a partition wall 26. The cylinder 24 is a cylindrical conductor having one end with a bottom and the other end opened. The cylinder 24 is connected to the operation rod 25 so as to be flush with the tip of the operation rod 25 and moves together with the operation rod 25. . Specifically, the cylinder 24 has an inner diameter larger than the outer diameter of the operation rod 25 and has a common central axis with the operation rod 25. The bottomed portion has a disk shape, extends from the outer peripheral edge of the operation rod 25 in a flange shape, and the side peripheral wall standing on the bottomed portion extends in the opposite direction to the opposed contact portion 10.

  The piston 27 is a donut-shaped flat plate, and the operation rod 25 is slidably passed through the opening. The outer diameter of the piston 27 matches the inner diameter of the cylinder 24 and is fitted into the cylinder 24. The piston 27 is integrally formed and is fixed in position in the sealed container by a piston support 28 extending in a direction opposite to the facing contact portion 10.

  A communication hole 27 a that penetrates the flat plate is formed around the opening of the piston 27. A floating check valve 27b is attached to the communication hole 27a. The check valve 27 b has a wedge shape, and has a pointed end inserted into the communication hole 27 a from the inside of the mechanical puffer chamber 31. The existence range of the check valve 27b is regulated by the piston 27 and the stopper 27c.

  The partition wall 26 is a donut-shaped flat plate whose outer diameter matches the inner diameter of the cylinder 24, and is fitted and fixed so as to expand perpendicularly to the central axis in the middle of the cylinder 24 in the axial direction. 25 penetrates slidably. The partition wall 26 partitions the hollow interior of the cylinder 24 into two chambers arranged in series in the axial direction.

  The partition wall 26 is provided with a communication hole 26a that connects the two chambers. A floating check valve 26b is attached to the communication hole 26a. The check valve 26b has a wedge shape, and has a pointed end inserted into the communication hole 26a from the heat puffer chamber 30 side. The check valve 26b is restricted in its range by the partition wall 26 and the stopper 26c.

  A space on the opposite arc contact portion 11 side defined by the bottomed portion of the cylinder 24 and the partition wall 26 is a heat puffer chamber 30, which is opposite to the opposite arc contact member 11 defined by the partition wall 26 and the piston 27. Is a mechanical puffer chamber 31. The bottom of the cylinder 24 is provided with a communication hole 24 a that extends to the outside of the movable arc contact 21 around the movable arc contact 21, and connects the heat puffer chamber 30 and the outdoor space to the opposing arc contact 11 side. Are connected.

  The insulating nozzle 23 is erected on the surface of the bottom portion of the cylinder 24 on the side of the counter arc contact 21. The insulating nozzle 23 is erected so as to surround the communication hole 24a with the heat puffer chamber 30, and extends along the central axis toward the counter arc contact 11 while enclosing the movable arc contact 21 at a predetermined interval. After passing through the tip of the movable arc contact 21, the inner diameter is narrowed to a degree slightly larger than the outer diameter of the opposed arc contact 11, and linearly expands toward the tip when reaching the throat portion that becomes the minimum inner diameter portion. It has become.

  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 inward, and the inner diameter of the opening edge and the outer diameter of the movable energizing contact 22 are the same. When the movable energizing contact 22 is inserted into the opening of the opposed energizing contact 12, the inner surface of the opposed energizing contact 12 and the outer surface of the movable energizing contact 22 are brought into contact with each other, so that electrical conduction can be achieved.

  The movable energizing contact 22 is a conductor having a cylindrical shape with an open end face, and a cylindrical wall is provided on the outer side of the insulating nozzle 23 so as to stand on the bottomed portion of the cylinder 24 toward the opposing energizing contact 12. doing. Further, the opposed energizing contact 12 is provided with a cylindrical wall outside the opposed arc contact 21, and is erected on one surface of the fixed support 13 toward the movable energizing contact 22.

(Function)
(Blocking operation)
In the energized state, as shown in FIG. 3, the fixed support 13, the opposing energizing contact 12, the movable energizing contact 21, and the cylinder 24 are electrically connected, and these members are one of the electric paths. Although not particularly illustrated, two conductors are fixed to the opposing contact portion 10 side and the movable contact portion 20 side by spacers in the sealed container, respectively. The spacer insulates the sealed container from the conductor and supports the conductor. In the energized state, the current flows into the gas circuit breaker through a bushing (not shown), and the member that becomes the above-mentioned electric path from the conductor on the opposed contact portion 10 side, and the conductor and the bushing on the movable contact portion 20 side (not shown) To the outside of the gas circuit breaker.

  When it is necessary to interrupt an accident current, a small advance current, a delayed load current such as a reactor interruption, or an extremely small accident current, the operation rod 25 receives the operation force of the driving device as shown in FIG. It moves along the central axis in the direction opposite to the part 10. Then, the movable contact portion 20 moves along the central axis so as to be separated from the opposed contact portion 10, and the movable energized contact 22 is separated from the opposed energized contact 12.

  Further, as the movable contact portion 20 moves, the cylinder 24 connected to the operation rod 25 moves so that the bottomed portion approaches the fixed piston 27, so that the volume of the mechanical puffer chamber 31 is reduced. The arc extinguishing gas in the mechanical puffer chamber 31 is accumulated according to Boyle's law. At this time, the floating check valve 26b cannot move following the movable contact portion 20 due to inertial force, and the mechanical puffer chamber 31 and the heat puffer chamber 30 communicate with each other through the communication hole 26a. Therefore, the compressed arc extinguishing gas flows into the heat puffer chamber 30 from the mechanical puffer chamber 31 and pressurizes the heat puffer chamber 30.

  When the interruption operation further proceeds and the movable arc contact 21 is separated from the opposed arc contact 11, an arc discharge is generated between the movable tip 11 b of the opposed arc contact 11 and the movable arc contact 21. Arc.

  Since arc discharge is very high temperature, high temperature gas is generated from the arc discharge, and the surrounding arc extinguishing gas heated by the arc discharge also becomes high temperature. Unlike the mechanical puffer chamber 31, the heat puffer chamber 30 is defined by a partition wall 26 fixed to the cylinder 24, and has a volume unchanged. However, when the thermal energy derived from the arc discharge is taken into the thermal puffer chamber 30, the arc extinguishing gas in the thermal puffer chamber 30 is further boosted according to Boyle-Charle's law.

  When the interruption operation further proceeds, the distance between the opposed arc contact 11 and the movable arc contact 21 is sufficiently opened, and the heat puffer chamber 30 is sufficiently accumulated, the arc extinguishing gas in the heat puffer chamber 30 passes through the communication hole 24a. It passes through and is ejected into the insulating nozzle 23. The arc extinguishing gas that has become a jet is guided toward the arc discharge using the gas flow path between the insulating nozzle 23 and the movable arc contact 21 and is strongly blown against the arc discharge. When the current zero point is reached, the arc discharge is extinguished in combination with the blowing of a strong arc extinguishing gas, and the current interruption is completed.

  In addition, the arc-extinguishing gas which ejected is discharged | emitted to the movable contact part 20 side and the opposing contact part 10 side. Specifically, the fixed support 13 is formed with an opening other than the standing region of the opposed arc contact 11 and the opposed energized contact 12, and the arc extinguishing gas is in contact with the opposed arc contact 11 and the opposed energized contact. It flows as a gas flow path between the child 12 and escapes from the fixed support 13. The arc extinguishing gas passes through the hollow interior of the cylindrical movable arc contact 21 having both ends open and the operation rod 25 having an open end face where the movable arc contact 21 is erected, and a tapered surface 25a provided in the middle. Then, while being guided by the communication hole 25b on the side wall of the operation rod 25, it is pulled out to the sealed container.

(Loading operation)
Next, in the closing operation, as shown in FIG. 2, the operating rod 25 moves along the central axis in the direction of the opposed contact portion 10 in response to the operating force of the driving device. If it does so, the movable contact part 20 will approach the opposing contact part 10 and will move along a central axis so that it may contact soon, and the movable energization contact 22 will be conducted with respect to the opposing energization contact 12.

  Further, as the movable contact portion 20 moves, the cylinder 24 connected to the operation rod 25 moves so that the bottomed portion thereof is separated from the fixed piston 27, so that the volume of the mechanical puffer chamber 31 is increased. The arc extinguishing gas in the mechanical puffer chamber 31 becomes a negative pressure with respect to the inside of the sealed container in accordance with Boyle's law. At this time, the floating check valve 27b opens due to a pressure difference between the mechanical puffer chamber 31 and the sealed container, and the arc extinguishing gas in the sealed container flows into the mechanical puffer chamber 31 through the communication hole 27a. And the pressure in the sealed container is the same.

  In the movement of the movable contact portion 20, the movable arc contact 21 contacts the opposed arc contact 11. When the opposed arc contact 11 and the movable arc contact 21 come into contact, an impact force is applied to the movable arc contact 21 in a direction opposite to the opposed contact portion 10, and the movable tip end 11 b of the opposed arc contact 11 is applied. The impact force is applied in the direction of immersing in the fixed cylindrical portion 11a.

  At this time, the movable tip portion 11b is pushed into the fixed cylindrical portion 11a by elastic deformation of the sliding portion 11c, and accumulates the elastic body 11d. Therefore, the elastic body 11d absorbs the impact force received by the counter arc contact 11 and the movable arc contact 21, and the impact force on both is greatly reduced.

  The energized state starts from the time of contact, but the movement of the movable contact portion 20 continues to a predetermined full insertion position. Meanwhile, the sliding portion 11c allows the movable tip portion 11b to change due to elastic deformation, and the elastic body 11d continues to absorb the impact force due to the change. Then, when the fully inserted position is reached, the movement of the movable contact portion 20 stops. At this time, as shown in FIG. 3, since the force for immersing the movable tip portion 11b into the fixed cylindrical portion 11a is released, the stored force of the elastic body 11d is released, and the movable tip portion 11b is fixed to the fixed cylindrical portion. It tries to swing in the direction protruding from 11a and the direction of immersion. However, a stopper 11e made of an impact buffer provided on the movable tip portion 11b engages with the sliding portion 11c so as to prevent the elastic body 11d from expanding and contracting, thereby suppressing the swing of the movable tip portion 11b.

(effect)
As described above, in the gas circuit breaker according to the present embodiment, the opposed arc contact 11 included in the opposed contact portion 10 is constituted by the fixed cylindrical portion 11a and the movable tip portion 11b. The fixed cylindrical portion 11a has an opening at the end facing the movable contact portion 20, and the movable tip portion 11b protrudes from the opening of the fixed cylindrical portion 11a and extends so as to be contactable toward the movable contact portion 20. . The fixed cylindrical portion 11a is provided with a sliding portion 11c that is formed from the inner edge of the opening and supports the movable tip portion 11b so as to be slidable in the advancing and retracting direction with respect to the fixed cylindrical portion 11a.

  Thereby, the impact at the time of the collision of the movable arc contact 21 and the counter arc contact 11 during the closing operation can be reduced. For this reason, it is possible to reduce damage at the tips of the two contactors 11 and 21 that become a high electric field portion when advancing a small current, and it is possible to suppress further increase in the electric field due to damage such as surface roughness and shape change. Accordingly, even when a low operating force is applied to the operating rod 25 at the time of cutting off a small current, that is, without promptly increasing the opening speed, a quick insulation recovery can be obtained and a good small current cutting performance can be obtained. Is possible.

  The fixed cylindrical portion 11a and the movable tip portion 11b can be provided on the movable contact portion 20 side, can be provided on both the opposed contact portion 10 and the movable contact portion 20, or otherwise. Any member that sometimes produces contact impact force can be applied. Thereby, the damage reduction of an application location can also be aimed at.

  Further, an elastic body 11d that absorbs a contact impact force received by the movable tip portion 11b at the time of charging is provided. For example, the elastic body 11d is accommodated in a hollow portion of the fixed cylindrical portion 11a, and the movable tip portion 11b is connected to the elastic body 11d in the hollow portion. If the movable tip portion 11b can be advanced and retracted by the sliding portion 11c, the contact collision force with the movable arc contact 21 and the counter arc contact 11 can be reduced to some extent. However, due to the presence of this elastic force, it is possible to maintain appropriate contact between the movable arc contact 21 and the counter arc contact 11 after being thrown in while reducing the impact of the movable tip portion 11b. The elastic body 11d that absorbs the contact impact force received by the movable tip portion 11b is not limited to this mode, and may be provided at an appropriate location in accordance with structural convenience.

  Moreover, the sliding part 11c has electroconductivity, and also has elasticity at least in the contact part with the movable front-end | tip part 11b. This facilitates sliding of the movable tip portion 11b without providing play around the movable tip portion 11b, and can prevent a decrease in conduction reliability due to the provision of play. However, the aspect of the sliding portion 11c is not limited to this as long as the continuity between the movable tip portion 11b and the fixed cylindrical portion 11a can be secured in addition to the sliding portion 11c. For example, an energization part may be provided in the hollow part of the fixed cylindrical part 11a, and the energization part may be made of a material having conductivity and elasticity.

  In addition, the movable tip portion 11b is further provided with a stopper 11e made of an impact buffer material and preventing a predetermined protrusion or more from the fixed cylindrical portion 11a. Thereby, it is possible to effectively suppress the swing of the movable tip portion 11b due to the release of the accumulating force of the elastic body 11d, and the movable arc contact 21 and the slide due to the swing of the movable tip portion 11b. It becomes easy to avoid rubbing wear with the portion 11c. However, in addition to providing the stopper 11e, the elastic constant and free length of the elastic body 11d may be adjusted to suppress the swing.

(Modification)
In the present embodiment, the serial puffer type gas circuit breaker effective for the advance and small current interruption has been described as an example. However, the wear due to contact at the time of charging is not limited to the series buffer type, and can be applied to other than the serial buffer type gas circuit breaker.

  For example, FIG. 4 shows a gas circuit breaker that blows arc-extinguishing gas onto arc discharge by mechanical compression. There is no partition wall 26 inside the cylinder 24, and the inside of the cylinder 24 is only a mechanical puffer chamber. Yes.

  Even in this gas circuit breaker, when the movable contact portion 20 moves, the movable arc contact 21 contacts the opposed arc contact 11. When the opposed arc contact 11 and the movable arc contact 21 come into contact, an impact force is applied to the movable arc contact 21 in a direction opposite to the opposed contact portion 10, and the movable tip end 11 b of the opposed arc contact 11 is applied. The impact force is applied in the direction of immersing in the fixed cylindrical portion 11a.

  Therefore, the impact force is greatly reduced by separating the opposed arc contactor 11 into a fixed cylindrical part 11a and a movable tip part 11b, and a sliding part 11c between the fixed cylindrical part 11a and the movable tip part 11b. The elastic body 11d can be provided in the fixed cylindrical portion 11a, or the stopper 11e can be disposed.

(Other embodiments)
In the present specification, an embodiment according to the present invention has been described. However, this embodiment is presented as an example, and is not intended to limit the scope of the invention. Combinations of all or any of the configurations disclosed in the embodiments are 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. This embodiment and its modifications are included in the scope of the present invention and the gist thereof, and are also included in the invention described in the claims and the equivalent scope thereof.

  For example, the gas circuit breaker according to this embodiment or the modification is configured to fix the opposed contact portion 10 and move only the movable contact portion 20 in the axial direction. A so-called dual motion mechanism may be employed in which the opposing contact portion 10 is also moved in the axial direction so that the child portion 20 moves relatively, thereby improving the relative opening speed.

DESCRIPTION OF SYMBOLS 10 Opposed contact part 11 Opposed arc contact 11a Fixed cylindrical part 11b Movable front-end | tip part 11c Sliding part 11d Elastic body 11e Stopper 12 Opposite energization contact 13 Fixed support 20 Movable contact part 21 Movable arc contact 22 Movable energization contact Element 23 Insulating nozzle 24 Cylinder 24a Communication hole 25 Operation rod 25a Tapered surface 25b Communication hole 26 Bulkhead 26a Communication hole 26b Check valve 26c Stopper 27 Piston 27a Communication hole 27b Check valve 27c Stopper 28 Piston support 30 Thermal puff chamber 31 Mechanical puffer Room

Claims (9)

A gas circuit breaker that switches between current interruption and input,
A sealed container filled with arc-extinguishing gas;
A first contact part and a second contact part, which are arranged opposite to each other in the sealed container and contact or separate from each other at the time of charging or blocking;
With
At least one of the first contact portion or the second contact portion is:
A fixed cylindrical portion having an opening at an end facing the other;
A movable tip projecting from the opening and extending in contact with the other;
A sliding portion that consists of an inner edge of the opening and supports the movable tip portion so as to be slidable in the advancing and retracting direction with respect to the fixed cylindrical portion;
Providing
A gas circuit breaker characterized by Further comprising an elastic body that absorbs the contact impact force received by the movable tip when being thrown in,
The gas circuit breaker according to claim 1. The elastic body is accommodated in a hollow portion of the fixed cylindrical portion,
The movable tip is connected to the elastic body in the hollow portion;
The gas circuit breaker according to claim 2. The sliding portion has conductivity, and further has elasticity at least in a contact portion with the movable tip portion;
The gas circuit breaker according to any one of claims 1 to 3. The hollow portion of the fixed cylindrical portion further includes a current-carrying portion that has conductivity and elasticity and is energized with the movable tip portion,
The gas circuit breaker according to any one of claims 1 to 4. The movable tip portion is made of an impact buffer material, and further includes a stopper for preventing a predetermined protrusion or more from the fixed cylindrical portion,
The gas circuit breaker according to any one of claims 1 to 5. The first contact portion and the second contact portion are:
An energizing contact for energizing between the first contact portion and the second contact portion;
An arc contact that undertakes an arc discharge generated when the first contact portion or the second contact portion is separated; and
Each with
The fixed cylindrical portion, the movable tip portion, and the sliding portion constitute both or one of the arc contacts;
The gas circuit breaker according to any one of claims 1 to 6. Gas flow generating means for blowing off the arc-extinguishing gas against the arc plasma generated between the first contact and the second contact in the course of current interruption;
The gas flow generating means includes
A thermal puffer chamber that communicates directly or indirectly with the generation space of the arc plasma, receives the hot gas in the generation space inside, and is accumulated by a heating pressure-increasing action;
A mechanical puffer chamber which communicates with the thermal puffer chamber and whose volume decreases with the separation of the first contact portion and the second contact portion;
Have
Blowing the arc-extinguishing gas against the arc plasma in combination with a heating pressurization action and a mechanical compression action;
A gas circuit breaker according to any one of claims 1 to 7. A gas flow generating means for blowing off the arc extinguishing gas against the arc plasma generated between the first contact portion and the second contact portion in the process of current interruption;
The gas flow generating means includes
A mechanical puffer chamber that communicates directly or indirectly with the arc plasma generation space and has a volume that decreases with the separation of the first contact portion and the second contact portion;
Blowing the arc-extinguishing gas against the arc plasma at least by mechanical compression;
A gas circuit breaker according to any one of claims 1 to 7.

Images