JP4930259B2 - Gas switch - Google Patents

Description

  The present invention relates to a gas switch that performs a current interrupting operation by extinguishing an arc generated between a fixed arc contact and a movable arc contact provided in an arc extinguishing chamber with an arc extinguishing gas.

  Arc contacts used in gas switches such as gas circuit breakers and gas disconnectors have heat resistance to withstand the high-temperature arc generated when the current is interrupted, and in addition to a certain level to commutate the arc current. Conductivity is also required. Therefore, an alloy in which a material having a high melting point and excellent arc resistance is combined with a material having excellent conductivity is used. Specifically, alloys composed of copper and tungsten (Cu—W alloy) are widely used.

  As for the arc contact of the conventional gas circuit breaker, the fixed arc contact and the tip portion of the movable arc contact that is in contact with the fixed arc contact to the end are made of a Cu-W alloy (for example, Patent Document 1).

  Moreover, in order to always press the inner peripheral surface of the movable arc contact from the fixed arc contact during fitting, an arc contact having a slit formed along the axis of the fixed arc contact has been disclosed ( For example, see Patent Document 2).

Japanese Patent Laid-Open No. 11-73860 (page 6, FIG. 12) JP 2001-110288 A (page 3-4, FIG. 1 and FIG. 5)

  In the arc contactor used for the gas switch, the temperature at the tip of the arc contactor rapidly increases due to arc heat at the time of current interruption, and then decreases. At this time, a temperature gradient is generated in the depth direction from the tip portion, and thus a plurality of cracks progress in the depth direction. Further, when the current is interrupted a plurality of times, thermal stress is repeatedly generated at the boundary where the temperature difference between the tip and the inside of the arc contact occurs, and a crack develops at the boundary. In other words, the crack that has developed in the depth direction from the surface of the tip part changes the direction of propagation to the direction parallel to the surface of the tip part exposed to the arc (hereinafter referred to as the transverse direction) by repeating the interruption, and arc contact Progress inside the child. Therefore, there is a problem that a part of the material falls off from the surface of the arc contact and wears due to a lateral internal crack generated just under the surface of the arc contact.

  However, the arc contactor used in the conventional gas switch disclosed in Patent Document 1 is constant against wear due to evaporation when the arc contact surface is heated by the arc heat at the time of current interruption. However, the above-described problem that a part of the surface of the arc contactor falls off and wears out cannot be prevented.

  Moreover, in the arc contact provided with the slit which crosses with an axial center as shown in patent document 2, the stability of the fitting state of a movable arc contact and a fixed arc contact, or the escape of an insulating gas is suppressed. There is an effect, and it is considered that there is a certain effect to reduce the thermal stress. However, since the slits are formed only to intersect at the axial center position, the thermal stress acting in the diameter direction of the arc contact cannot be effectively reduced. For this reason, there is a problem that internal cracks generated in the diameter direction cannot be effectively suppressed, and wear due to dropout cannot be reduced. When the surface of the arc contact is dropped, a sharp part is formed on the surface of the arc contact, and the arc is concentrated on the sharp part, resulting in an unstable arc when the current is interrupted. .

  The present invention has been made in order to solve the above-described problems, and suppresses the lateral progress of internal cracks generated immediately below the surface of the arc contactor, thereby reducing the wear due to the dropout of the surface. The purpose is to obtain a contact.

  The gas switch according to the present invention includes a fixed arc contact and a movable arc contact disposed so as to be opposed to and can be separated from the fixed arc contact. Between the fixed arc contact and the movable arc contact. A gas switch that performs a current interrupting operation by extinguishing a generated arc with an arc extinguishing gas, wherein at least one of a fixed arc contact and a movable arc contact is a base made of an alloy of copper and tungsten. A slit having at least one of a concentric shape, a lattice shape, and a stripe shape is provided in the depth direction from the surface exposed to the arc on the material.

  In the gas switch according to the present invention, since the slit having at least one of concentric, grid, and striped shapes is provided in the depth direction from the surface exposed to the arc, the diameter of the arc contactor Since the thermal stress acting in the direction can be effectively relaxed, internal cracks generated in the diameter direction can be effectively suppressed. As a result, it is possible to reduce the wear due to the drop-off of the surface member of the arc contact, and there is a remarkable effect that the stable interruption performance can be maintained.

Embodiment 1 FIG.
FIG. 1 is a schematic cross-sectional view of a gas circuit breaker according to Embodiment 1 for carrying out the present invention. In FIG. 1, a gas circuit breaker 1 includes an arc extinguishing chamber 5 having a fixed electrode portion 2, a movable electrode portion 3, and an insulating cylinder 4, an insulating operation rod 6 interlocked with the movable electrode portion 3, and a supporting insulating cylinder. 7, a cooling tower 8 coupled to the fixed electrode portion 2, a conductor 9a, a bushing 10a and a terminal 11a for deriving the solid electrode portion 2, a conductor 9b, a bushing 10b for deriving the movable electrode portion 3, and It is comprised with the terminal 11b and the container 12 which accommodated the arc-extinguishing gas and the above-mentioned structural member inside. One end of the insulating operation rod 6 is led out from the container 12 and connected to an operation device 14 inside the control box 13 installed in close contact with the container 12.

  FIG. 2 is a schematic cross-sectional view for explaining the internal configuration of the arc extinguishing chamber 5 in the present embodiment. In FIG. 2, the fixed electrode portion 2 and the movable electrode portion 3 are electrically insulated and fixed by an insulating cylinder 4. A cylindrical movable arc contact 15 is disposed inside the nozzle 16 at the tip of the movable electrode 3. The other end of the movable arc contact 15 is connected to the insulating operation rod 6 via a drive rod 17. A movable main contact 18 is fixed outside the movable arc contact 15. A fixed main contact 19 and a rod-shaped fixed arc contact 20 are fixed to the fixed electrode portion 2. The movable main contact 18 and the fixed main contact 19 are partially covered with shields 21 and 22, respectively. Further, the movable electrode portion 3 is provided with a puffer cylinder 23 for flowing an arc-extinguishing gas into the nozzle 16 when shut off.

  Next, the current interruption operation in the arc extinguishing chamber 5 will be described. When the current is interrupted, the movable arc contact 15 on the movable electrode 3 side is separated from the fixed arc contact 20 that has been in contact with the contact, and then an arc is generated between the contacts. . In FIG. 2, this arc is shown as A1. On the other hand, the arc extinguishing gas compressed in the puffer cylinder 23 is blown to the arc A1 and flows into the nozzle 16 to extinguish the arc A1. While the arc is generated and the arc is extinguished with the arc-extinguishing gas, the fixed arc contact 20 and the movable arc contact 15 are exposed to a very high temperature (about 20000 K) by the hot arc A1.

  In the gas circuit breaker that operates in this way, an arc-resistant material having conductivity is used as a base material at the distal ends of the fixed arc contact 20 and the movable arc contact 15, and usually tungsten is 50 to 90 weight. % Copper alloy is used.

  FIG. 3 is a schematic diagram of the distal end portion of the fixed arc contact in the present embodiment. In FIG. 3, the base material 24 of the fixed arc contact 20 is an alloy (Cu—W alloy) made of copper and tungsten, and the base material 24 is concentric in the depth direction from the surface in contact with the arc. A slit 25 is provided. The base material 24 is joined to a base metal 26 made of copper or a copper alloy by brazing or the like.

  4 and 5 are a top view and a cross-sectional view, respectively, of the fixed arc contact in the present embodiment shown in FIG.

  In the rod-shaped fixed arc contact 20 used for the current interrupting part of the gas circuit breaker, the temperature of the tip part rapidly rises and decreases due to the arc heat at the time of current interrupting. At that time, a temperature gradient is generated from the tip portion to the depth direction, so that cracks in the depth direction develop. Further, when the current is interrupted a plurality of times, thermal stress is repeatedly generated at the boundary of the temperature difference between the tip and the inside of the contact, and a crack develops at the boundary. In other words, the crack that has developed in the depth direction at the beginning of the interruption changes the propagation direction in the lateral direction by repeating the interruption. Therefore, the portion where the internal crack in the lateral direction has developed just below the surface of the fixed arc contact 20 falls off from the surface of the arc contact and wears out.

  However, by providing the concentric slit 25 from the surface exposed to the arc of the fixed arc contact 20 in the depth direction as in the present embodiment, the thermal stress generated at the tip is dispersed. The progress of internal cracks in the lateral direction can be suppressed. As a result, it is possible to reduce wear due to dropout of the surface of the arc contact.

  In this embodiment, the concentric slit 25 is provided in the rod-shaped fixed arc contact 20, but it may be provided in the cylindrical movable arc contact 15 or in both arc contacts. Also good.

  In the arc contact, the weight ratio of the Cu—W alloy is preferably 50% by weight to 90% by weight W and the balance is Cu, and the average particle size of the W powder used as a raw material is 20 μm or less. It is preferable. The reason for this is that if the weight ratio of W is less than 50% by weight, the heat resistance against arc heat is impaired and wear increases, and if it exceeds 90% by weight, the thermal conductivity deteriorates and evaporation wear is promoted. This is because cracks are likely to occur. Moreover, it is because wear may increase when the average particle diameter of W powder exceeds 20 micrometers.

  The manufacturing method of the Cu-W alloy used for the arc contact of this invention should just use the well-known powder metallurgy technique, for example, an infiltration method, a sintering method, a discharge plasma sintering method, electricity supply It is manufactured by a heat sintering method, a hot press sintering method, a hot extrusion method, a metal powder injection molding method or the like, and is not particularly limited.

  A method of providing the slit is not particularly limited as long as a known processing technique or brazing technique is used. The depth of the slit is preferably provided so as to exceed the boundary where the temperature difference between the tip of the arc contact and the inside of the arc contact occurs at the time of interruption, that is, the depth reaching the melting point of Cu (1083 ° C.). The effect of dispersing and relaxing the thermal stress is further improved.

  In addition, in this Embodiment, although the example of the arc contactor of the gas circuit breaker which is one of the gas switches was demonstrated, you may use for the arc contactor of a gas disconnector.

Embodiment 2. FIG.
In the second embodiment, a grid-like slit 25 is provided in the depth direction from the surface of the fixed arc contact 20 exposed to the arc. FIG. 6 is a top view of the fixed arc contact in the present embodiment.

  In the fixed arc contact configured as described above, the lattice-like slits 25 are provided in the depth direction from the surface exposed to the arc, so that the thermal stress generated at the tip portion is dispersed and the lateral direction. The progress of internal cracks can be suppressed. As a result, it is possible to reduce wear due to dropout of the surface of the arc contact.

Embodiment 3 FIG.
The third embodiment is a case in which striped slits 25 are provided in the depth direction from the surface of the fixed arc contact 20 exposed to the arc. FIG. 7 is a top view of the fixed arc contact in the present embodiment.

  In the fixed arc contact configured as described above, the striped slit 25 is provided in the depth direction from the surface exposed to the arc, so that the thermal stress generated at the tip is dispersed and the lateral direction The progress of internal cracks can be suppressed. As a result, it is possible to reduce wear due to dropout of the surface of the arc contact.

Embodiment 4 FIG.
In the fourth embodiment, a concentric slit 25 and a cruciform slit 25 intersecting at the axis of the fixed arc contact are provided in the depth direction from the surface of the fixed arc contact 20 exposed to the arc. This is the case. FIG. 8 is a schematic diagram of the distal end portion of the fixed arc contact in the present embodiment. FIG. 9 is a top view of the fixed arc contact shown in FIG.

  In the fixed arc contact configured as described above, the concentric slit 25 and the cross-shaped slit 25 are provided in the depth direction from the surface exposed to the arc, so that the heat generated at the tip portion is provided. The stress is dispersed, and the development of lateral internal cracks can be suppressed. As a result, it is possible to reduce wear due to dropout of the surface of the arc contact.

  FIG. 10 is a top view of a fixed arc contact when another lattice structure 25 and a cross-shaped slit 25 intersecting at the axis of the fixed arc contact are combined as another configuration in the present embodiment. Moreover, FIG. 11 is a top view of a fixed arc contact when a striped slit 25 and a cross-shaped slit 25 intersecting at the axis of the fixed arc contact are combined as still another configuration. In the fixed arc contact configured as described above, it is possible to effectively relieve the thermal stress generated in the circumferential direction when the tip exposed to the arc is viewed from above, and as a result, the lateral direction Therefore, it is possible to further reduce the wear due to the drop of the surface of the arc contact.

Embodiment 5 FIG.
In the fifth embodiment, a Cu portion 27 is disposed at the bottom of a concentric slit 25 similar to the first embodiment. FIG. 12 is a cross-sectional view of the fixed arc contact in the present embodiment. In the method for manufacturing a fixed arc contact in the present embodiment, a desired Cu—W alloy is prepared and processed into an arc contact having a desired size. Next, a concentric slit is processed at the tip of the arc contact. Then, a Cu plate slightly smaller than the slit width of the concentric slit is inserted into the slit and disposed at the bottom of the slit. And it heated above the melting | fusing point of Cu in non-oxidizing atmosphere, Cu was fuse | melted, and what was cooled after that was finish-processed, and the arc contactor was obtained.

  In the fixed arc contact configured as described above, by arranging the Cu portion 27 at the bottom of the slit 25, in addition to the effect of relieving the thermal stress of the slit, the temperature at the tip of the slit is released into the contact. The temperature distribution in the depth direction becomes small. As a result, the occurrence of internal cracks in the lateral direction can be effectively suppressed, so that wear due to dropping off of the surface of the arc contact can be further reduced.

  In the present embodiment, the Cu portion 27 is formed at the bottom of the concentric slit 25. However, the shape of the slit 25 is not limited to the concentric shape, but a lattice shape, a stripe shape, or the like. Even if the Cu portion 27 is formed at the bottom of the slit 25 having the same, the same effect is obtained.

Embodiment 6 FIG.
In the sixth embodiment, the results of evaluating the arc contact dropout wear by the interruption test for the arc contacts having the structures described in the first to fifth embodiments will be described.

  A fixed arc contact having a diameter of 15 mm and a length of 25 mm and a movable arc contact having a diameter of 25 mm, an inner diameter of 10 mm, and a length of 30 mm were prepared. The composition of the fixed arc contact and the movable arc contact is Cu-70 wt% W.

  And the fixed arc contact thing of the sample numbers 1-6 was prepared. The movable arc contact is not provided with a slit.

  Sample No. 1 was provided with concentric slits 25 and provided with concentric slits 25 having a diameter of 5 mm and a diameter of 10 mm. The width of the slit 25 was 0.5 mm, and the depth was 6 mm from the contact tip.

  Sample No. 2 was provided with a grid-like slit 25, and a 5 mm square grid was arranged at the center. The width of the slit 25 was 0.5 mm, and the depth was 6 mm from the contact tip.

  Sample No. 3 was provided with striped slits 25, and the slits 25 were provided at intervals of 4 mm. The width of the slit 25 was 0.5 mm, and the depth was 6 mm from the contact tip.

  Sample No. 4 is a combination of a concentric circle and a cross-shaped slit 25 that intersects with the axis of the fixed arc contact. The concentric slit 25 has a diameter of 5 mm and a diameter of 10 mm, and the cross-shaped slit 25 is a contact. It was set up to intersect at the center. The width of the slit 25 was 0.5 mm, and the depth was 6 mm from the contact tip.

  Sample No. 5 was provided with a grid-like slit 25, and a Cu portion 27 was placed at the bottom of the slit 25, and a 5 mm square grid was placed at the center. The width of the slit 25 was 0.7 mm, and the depth was 6 mm from the contact tip. A Cu portion 27 is embedded 3 mm from the bottom of the slit 25.

  Sample No. 6 is a combination of a concentric circle and a cross-shaped slit 25 that intersects with the axis of the fixed arc contact, and a Cu portion 27 is disposed at the bottom of the slit 25. Is equivalent to The width of the slit 25 was 0.7 mm, and the depth was 6 mm from the contact tip. A Cu portion 27 is embedded 3 mm from the bottom of the slit 25.

  Sample No. 7 is a comparative material, which is an arc contact in which only a cross-shaped slit that intersects with the axis of the fixed arc contact is formed.

  Sample number 8 is also a comparative material, and is an arc contact in which no slit is formed.

The interruption test was performed using a test facility that simulates an arc extinguishing chamber of a gas circuit breaker. After incorporating an arc contact in the test vessel, SF ₆ gas, which is an arc extinguishing gas, was filled and set to 4 atm. Next, when the fixed arc contactor and the movable arc contactor are brought into contact with each other, the interruption test in which a current of 20 kArms is loaded for 0.5 cycles is performed five times, and then the mechanical opening and closing is performed five times. It was. Then, the surface of the fixed arc contact was visually observed, and the presence or absence of dropout on the contact surface was evaluated.

  Table 1 shows concentric slits, slits combining concentric circles and crosses, lattice slits, striped slits, fixed arc contactors each provided with a lattice slit in which a Cu portion is embedded in the bottom of the slit, As a comparison, the presence or absence of dropping of a fixed arc contact formed only with a cross-shaped slit intersecting at the axis of the fixed arc contact and a fixed arc contact formed with no slit is compared. In the judgment, “No dropout” is indicated as “Good”, and “No” is indicated as “Poor”.

  From the results of Table 1, the arc contact having only a cross-shaped slit intersecting with the axis of the fixed arc contact at the tip or the arc contact having no slit showed wear due to dropping. On the other hand, in the arc contact having the structure according to the present invention, cracks were observed on the surface exposed to the arc, but no wear due to surface dropping occurred.

  From these results, concentric circles, grids, stripes, concentric circles and crosses, and a slit with a Cu portion embedded in the slit bottom are provided in the depth direction from the surface exposed to the arc. It is possible to disperse and relieve the stress generated at the boundary that causes the temperature difference between the tip and the inside of the contact. In particular, it is possible to effectively relieve the thermal stress acting in the diametric direction of the arc contact, which could not be obtained with only the cross-shaped slits intersecting with the axis of the fixed arc contact, so that the internal diameter generated Cracks can be effectively suppressed. As a result, it is possible to reduce the wear due to the fall of the surface member of the arc contact and to obtain an arc contact that can maintain a stable breaking performance.

  In the present embodiment, the example of the fixed arc contact has been described, but the same effect can be obtained even if the same configuration is applied to the portion of the movable arc contact that is exposed to the arc.

Embodiment 7 FIG.
In the seventh embodiment, the width of the slit is changed in the fixed arc contactor having the grid-like slit shown in the second embodiment.

  Seven fixed arc contacts having a diameter of 15 mm, a length of 25 mm, and a radius of curvature of 7.5 mm at the tip are prepared, and each of six of them has a slit width of 0.01 mm (sample number 9), 0.1 mm ( Sample-like slits of sample number 10), 0.3 mm (sample number 11), 0.5 mm (sample number 12), 2.0 mm (sample number 13) and 2.5 mm (sample number 14) were formed. The slit was provided so that a 5 mm square lattice was arranged at the center. The slit width of 0.01 mm (sample number 9) was 8 mm, and the slit width of 0.1 to 2.5 mm (sample number 10 to 14) was 6 mm. The remaining one, as a comparative example, did not form a slit (sample number 15). The movable arc contacts facing these fixed arc contacts had a diameter of 25 mm, an inner diameter of 10 mm, a length of 30 mm, and a radius of curvature of the tip portion of 4 mm. The material of these fixed arc contact and movable arc contact is Cu-70 wt% W.

  A method for manufacturing a contact having a slit width of 0.01 mm (sample number 9) will be described. First, nine prism blocks made of Cu-70 wt% W (width 6 mm × length 6 mm × height 10 mm, width 6 mm × length 5 mm × height 10 mm, width 5 mm × length 5mm x 10mm in height), and each block is bundled around a block of width 5mm x length 5mm x height 10mm, and the divided blocks of width 17mm x length 17mm x height 10mm Obtained. A pedestal of Cu-70 wt% W alloy having a width of 17 mm, a height of 17 mm, and a length of 20 mm was joined to the surface of the bundled block with a width of 17 mm and a length of 17 mm by Ag brazing. Finished to predetermined sample dimensions.

  A contact having a slit width of 0.1 mm or more was formed by slitting a contact having a predetermined size. Contacts with slit widths of 0.1 mm and 0.3 mm formed slits by wire cutting, and contacts with slit widths of 0.5 mm, 2.0 mm and 2.5 mm formed slits with metal saw.

Next, the relationship between the slit width and the presence or absence of cracks and drop-offs and the degree of wear was examined by a blocking test. The interruption test uses test equipment simulating an arc extinguishing chamber of a gas circuit breaker, and after incorporating a fixed arc contact and a movable arc contact in a test vessel, the arc extinguishing gas SF ₆ gas is filled. The gas pressure was set to 4 atmospheres. Then, when the fixed arc contactor and the movable arc contactor are brought into contact with each other, the circuit is tested 5 times with a current of 20 kArms for 0.5 cycle, and then mechanically opened and closed 5 times. Carried out.

  The presence or absence of cracks and dropouts and the degree of wear were evaluated on the arc-exposed surface of the fixed-side arc contactor after the test by checking the presence and absence of cracks and dropouts by visual observation and observation with a stereomicroscope. The progress was examined, and the degree of wear was determined by comparison with the wear state of the contact with no slit of sample number 15.

  The degree of wear is 1 when there is no crack or dropout on the arc exposed surface and inside the contact, there are some internal cracks, but no crack on the arc exposed surface and no dropout, no crack on the arc exposed surface, The case where there were some internal cracks and dropouts was judged as 3, and the case where there were cracks and dropouts on the arc-exposed surface and inside the contacts was judged as 4.

  Table 2 is a characteristic table showing the relationship between the slit width, the presence or absence of cracks, dropout, and the degree of wear in the present embodiment. FIG. 13 is a characteristic diagram showing the relationship between the slit width and the evaluation point of the degree of wear in the present embodiment.

  As a result of the evaluation, a shell-like crack was generated on the arc-exposed surface of the contact (sample No. 15) having no slit corresponding to the conventional example, and dropping was also observed. In addition, as a result of cross-sectional observation, shell-shaped cracks on the arc-exposed surface have progressed in the depth direction, and some of the cracks that have further progressed in the depth direction are in the lateral direction (diameter direction of the arc contact). Progressing in a different direction, part of the material was missing from that part.

  On the other hand, in the contact (sample numbers 9 to 14) having a slit width in the range of 0.01 mm to 2.5 mm, the shell as seen on the arc-exposed surface of the contact without the slit (sample number 15). It was found that no cracks were generated and the effect of reducing the occurrence of cracks in the depth direction was obtained. Further, the contact with the slit width of 0.01 to 0.3 mm (sample numbers 9 to 11) had no internal cracks in the lateral direction, and no drop occurred. Further, in the contact (sample numbers 12 to 13) having a slit width of 0.5 to 2.0 mm, some cracks progressed vertically (lateral direction) from the inner wall of the slit, but no drop occurred. In the contact (sample number 14) having a slit width of 2.5 mm, cracks and dropouts that progressed vertically (laterally) from the inner wall of the slit occurred slightly. However, the degree of dropping and cracking was small as compared with the contact without slit (Sample No. 15). Further, there was no accumulation of solidified material of Cu and W melted by arc heat at the bottom of the slit of the contact (sample numbers 9 to 11) having a slit width of 0.01 to 0.3 mm. Cu and W coagulates were deposited on the bottom of the slits of the contacts (sample numbers 12 to 14) having a thickness of 0.5 to 2.5 mm.

  A portion where Cu is preferentially evaporated is formed on the inner wall of the slit by the arc heat. Cracks are likely to occur vertically (laterally) from the inner wall of the slit starting from the portion where Cu has evaporated. When the slit width is 2.5 mm or more, there is much wraparound of the arc heat, and by reducing the slit width to 2.0 mm or less, preferably 0.3 mm or less, the wraparound of the arc heat is reduced and the occurrence of lateral cracks is reduced. There is an inhibitory effect.

  As described above, the width of the slit is 2 mm or less, more preferably 0.3 mm or less, and by reducing the slit width as much as possible, the wraparound of the arc heat into the slit can be reduced. It is possible to suppress the occurrence of cracks that progress to the point. In addition, since there is an effect of suppressing the occurrence of shell-like cracks on the arc-exposed surface, that is, cracks in the depth direction, it is possible to reduce wear due to dropping off of the arc contact surface.

  In the present embodiment, as a method for obtaining an arc contact with a slit width as narrow as possible, a method for bundling divided blocks has been shown. However, as another method, a slit having a relatively large width is used. The slit width may be adjusted by forming and inserting a metal plate or the like of a desired material into the slit, and there is no particular limitation as long as the slit width can be adjusted.

  In the present embodiment, examples of lattice slits have been described. However, concentric slits, striped slits, cross-shaped slits, slits combining concentric circles and crosses, and slits combining lattices and crosses. The same effect can be obtained with a slit that combines stripes and crosses, and a slit in which a Cu portion is embedded in the bottom of the slit.

  Furthermore, in the present embodiment, an example in which a slit having one kind of slit width is provided for one fixed arc contact is described. However, the slit width is larger than 0 of the present invention and within a range of 2 mm or less. If it exists, the same effect can be acquired even if it provides in one arc contact combining the slit of a different width | variety.

  Furthermore, in the present embodiment, the example of the fixed arc contact has been described, but the same effect can be obtained even if the same configuration is applied to the portion of the movable arc contact that is exposed to the arc.

It is a cross-sectional schematic diagram of the gas circuit breaker in Embodiment 1 of this invention. It is a cross-sectional schematic diagram of the arc-extinguishing chamber in Embodiment 1 of this invention. It is a schematic diagram of the fixed arc contact in Embodiment 1 of this invention. It is a top view of the fixed arc contact in Embodiment 1 of this invention. It is sectional drawing of the fixed arc contactor in Embodiment 1 of this invention. It is a top view of the fixed arc contact in Embodiment 2 of this invention. It is a top view of the fixed arc contact in Embodiment 3 of this invention. It is a schematic diagram of the fixed arc contactor in Embodiment 4 of this invention. It is a top view of the fixed arc contact in Embodiment 4 of this invention. It is a top view of the fixed arc contact in Embodiment 4 of this invention. It is a top view of the fixed arc contact in Embodiment 4 of this invention. It is sectional drawing of the fixed arc contactor in Embodiment 5 of this invention. It is a characteristic view of the fixed arc contactor in Embodiment 7 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas circuit breaker 2 Fixed electrode part 3 Movable electrode part 4 Insulation cylinder 5 Arc-extinguishing chamber 6 Insulation operation rod 7 Support insulation cylinder 8 Cooling tower 9a, 9b Conductor 10a, 10b Bushing 11a, 11b Terminal 12 Container 13 Control box 14 Operation apparatus 15 movable arc contact 16 nozzle 17 drive rod 18 movable main contact 19 fixed main contact 20 fixed arc contact 21, 22 shield 23 puffer cylinder 24 base material 25 slit 26 base metal 27 Cu part

Claims (4)

A fixed arc contact and a movable arc contact disposed so as to be able to come in contact with and away from the fixed arc contact are provided, and the arc generated between the fixed arc contact and the movable arc contact is extinguished. In a gas switch that cuts off the current by extinguishing with gas,
At least one of the fixed arc contactor and the movable arc contactor is concentric, latticed, and striped in a depth direction from a surface exposed to the arc to a base material made of an alloy of copper and tungsten. A gas switch provided with at least one slit having a shape. The gas switch according to claim 1, further comprising a cross-shaped slit that intersects with the axis of the fixed arc contact. The gas switch according to claim 1 or 2, wherein a Cu portion is disposed at the bottom of the slit. The gas switch according to claim 1 or 2, wherein a width of the slit is greater than 0 and 2 mm or less.

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