KR102108817B1 - GIS breaker with ease of operation and insulated gas backflow prevention function - Google Patents

Abstract

The present invention relates to a gas insulated switchgear (GIS) breaker having operation ease and an insulated gas backflow prevention function. More specifically, the present invention relates to a GIS breaker having operation ease and an insulated gas backflow prevention function which effectively cools arc heat generated at the time of contact separation to prevent the insulation breakdown ability of insulated gas from being degraded, and particularly strengthens sealing properties between a pressure chamber and a heat chamber to block a backflow phenomenon of the insulated gas. Therefore, a safe and stable blocking function can be performed, and convenience of switching operation is increased to enable manual operation.

Description

GIS breaker with ease of operation and insulated gas backflow prevention function}

The present invention relates to a GIS circuit breaker having the ease of operation and the function of preventing the back flow of insulating gas, and more specifically, effectively cooling the arc heat generated when the contact is separated to prevent the deterioration of the insulating gas's ability to break down the insulation. By strengthening the sealing property between the heat chambers, it is possible to perform a safe and stable shut-off function by blocking the reverse flow phenomenon of the insulating gas, as well as to improve the convenience of switching operation and to enable manual operation. It is about a breaker for GIS with a function.

In general, gas insulated switchgear (GIS) is a water-substation facility that improves reliability by storing conductors and various protective devices by using an insulating gas that has excellent insulation and extinguishing functions in a metal sealed container. , And various components such as circuit breaker, disconnector, and ground switch are combined.

In addition, when a failure occurs in the power system, the fault current must be cut off quickly and safely in order to protect the system and various power devices.

At this time, the device that blocks the fault current is called a breaker, and is classified into a vacuum breaker, an oil breaker, and a gas breaker according to arc cancellation and insulation medium.

Here, when the breaker blocks the fault current, it means that the arc generated between the two contacts is interrupted when the fault current is cut off, and the gas circuit breaker according to the arc extinguishing method is a buffer type (puffer type). And complex extinction method.

In addition, a high voltage circuit breaker of 25.8 kV class or higher, and particularly preferably a high voltage circuit breaker of 72.5 kV or higher class, is a gas breaker of a paper extinguishing method that uses insulating gas (SF ₆ ) as an extinguishing and insulating medium.

Among these gas circuit breakers, the buffer type gas circuit breaker is a gas circuit breaker that compresses the extinguishing gas by mechanical operating force and boosts the extinguishing gas by using arc heat and blows it into the arc.

That is, when the breaker breaks the fault current, an arc is generated when the electrodes are separated, and the generated arc is extinguished using SF ₆ .

However, due to the arc generated during blocking, the surrounding insulating gas rapidly rises and falls to a very high temperature in a very short time, although the insulating gas at an extremely high temperature at a very high temperature decreases the breaking efficiency of the fault current because the blocking performance rapidly decreases. It will produce a problem.

Accordingly, there is a need to further reduce the cooling efficiency that can diffuse and cool the surrounding insulating gas as soon as possible when an arc occurs.

In addition, since the check valve installed between the pressure chamber and the heat chamber through which the insulating gas is conveyed is a simple flap type, the airtightness decreases and the backflow occurs when it is used for a long time. It may be the cause.

In addition, there is a need to improve so that it can be easily, easily, and quickly cut off even if manual operation is performed during switching.

Domestic registered patent No. 10-1621138 (2016.05.09.) 'Breaker breaker of gas-insulated switchgear with improved breaking performance' Domestic registered patent No. 10-1496903 (2015.02.23.) 'Combined SOHO gas circuit breaker with improved blocking performance'

The present invention was created to solve the above-mentioned problems in the prior art as described above, and effectively cools the arc heat generated when the contacts are separated to prevent the deterioration of the insulating gas of the insulating gas, particularly the pressure chamber and the heat chamber. By strengthening the sealing property between them, it is possible to perform a safe and stable shut-off function by blocking the reverse flow of insulating gas, as well as to improve the convenience of switching operation and to enable manual operation. The main purpose is to provide a circuit breaker for equipped GIS.

The present invention is a means for achieving the above object, the movable-side conductor part 10, the fixed-side conductor part 20, and a movable rod part 30 moving between them to switch between the input state and the cut-off state It includes; The movable-side conductor portion 10 or the fixed-side conductor portion 20 includes a cylindrical conductor 110 and 210 having a bottom surface, and an inner conductor pipe 120 and 220 connected to the interior of the conductors 110 and 210; The movable rod part 30 in the GIS circuit breaker including a pressure chamber 42 and a heat chamber 44 for transporting SF ₆ gas, and an operation shaft 31 for flowing the movable rod part 30 ;
A diaphragm DF is installed on a partition wall WAL that partitions the pressure chamber 42 and the heat chamber 44, but the diaphragm DF is screwed in a direction passing through the partition wall WAL, resulting in SF ₆ The cylinder 300 constituting the flow path PASS to allow gas to flow, the flange 310 formed at the exposed end of the heat chamber 44 of the cylinder 300, and the cylinder 300 formed with the flange 310 ) Is provided in the center of the inner end surface of the fixed body 330 fixed by a plurality of ribs 320 protruding from the inner circumferential surface of the cylinder 300, and the flange 310 is formed inclined to the inner circumferential end of the cylindrical body 300 The machined taper portion 340 and the counterflow preventing plate 350 that are in close contact with the flange 310 to open and close the flow path PASS, and penetrate the centers of the countercurrent preventing plate 350 and the fixed circular plate 330. The fixed rod 360 is screwed onto the fixed disk 330, the head portion 370 integrally fixed to the end of the fixed rod 360, and The elastic rod piece 380 is fitted between the fixed rod 360 and disposed between the backflow prevention plate 350 and the head portion 370 to elastically pressurize the backflow prevention plate 350, and the fixed rod 360 And a coil spring 390 interposed between the reverse flow prevention plate 350 and the head portion 370;
Inside the inner conductor pipe 120 of the movable-side conductor part 10, a movable-side diffusion buffer 400 is further installed, and the fixed-side diffusion inside the inner conductor pipe 220 of the fixed-side conductor part 20 The buffer 500 is further installed,
The movable side diffusion buffer 400 is fitted into a shaft inserting cylinder (TNG) provided to install the operating shaft 31 and the first buffer cup 410 with an open end facing the pressure chamber 42 , A second buffer cup 420 fitted to the shaft insertion tube (TNG) and fitted to an end of the first buffer cup 410, and the first and second buffer cups fitted to the shaft insertion tube (TNG) The first buffer spring 430 disposed between (410,420) and the shaft insertion cylinder (TNG), one end fixed to the inner wall surface of the conductor 110 and the other end of the second buffer cup 420 It includes a second buffer spring 440 fixed to the end;
The fixed-side diffusion buffer 500 is fitted into a contact rod (BNG) for fixing the fixed arc contact 24 installed at the inner center of the fixed-side conductor part 20, and the end facing the heat chamber 44 is opened. The third buffer cup 510, the fourth buffer cup 520 fitted to the contact rod BNG and fitted to the end of the third buffer cup 510, and the contact rod BNG A third buffer spring 530 disposed between the third and fourth buffer cups 510 and 520, and fitted to the contact bar BNG, one end being fixed to the inner wall surface of the conductor 210 and the other end being the fourth It includes a fourth buffer spring 540 fixed to the end of the buffer cup 520;
The outer circumferential surface of the first buffer cup 410 and the inner circumferential surface of the second buffer cup 420 coupled thereto are each formed with only 2 pitches of threads, and the rest are made up of minja, and after 2 pitches after screw assembly, separation is prevented Configured to be slidable;
On the outer circumferential surface of the third buffer cup 510 and the inner circumferential surface of the fourth buffer cup 520 coupled thereto, only 2 pitches of threads are formed, and the rest is composed of folks. Provided is a GIS circuit breaker having an easy to operate and an insulating gas backflow prevention function, which are configured to be slidable.

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According to the present invention, the arc heat generated at the time of contact separation is effectively cooled to prevent the deterioration of the insulating gas's ability to break down the insulation, and in particular, the sealing performance between the pressure chamber and the heat chamber is strengthened to block the reverse flow of the insulating gas, thereby ensuring safety and In addition to performing a stable shut-off function, it is possible to obtain an effect of implementing a manual operation by increasing the convenience of the switching operation.

1 is a cross-sectional view showing an input state of a circuit breaker provided in a GIS.
2 is a cross-sectional view showing a blocking state of a circuit breaker provided in the GIS.
3 is an explanatory view showing the exhaust path of SF ₆ , which is a high-temperature, high-pressure insulating gas in GIS.
Figure 4 is a cross-sectional view showing the operating state of the GIS circuit breaker according to the present invention.
5 is an exemplary diagram of a diaphragm constituting a GIS circuit breaker according to the present invention.
6 is an exemplary view of a diffusion buffer constituting a GIS circuit breaker according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

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1 and 2, the gas insulated switchgear, that is, the circuit breaker of the GIS includes a movable-side conductor portion 10, a fixed-side conductor portion 20 and a movable rod portion 30.

At this time, while the movable rod portion 30 is sliding on the movable side conductor portion 10, it is switched to an input state or a blocked state.

That is, whether the energization between the movable-side conductor part 10 and the fixed-side conductor part 20 varies depending on the position of the movable rod part 30.

For example, in the input state as shown in FIG. 1, the finger contact 22 of the fixed side conductor portion 20 is connected to the main contact 32 of the movable rod portion 30, and the fixed arc contact of the fixed side conductor portion 20 (24) is connected to the movable arc contact (34) of the movable rod section (30).

Accordingly, the fixed-side conductor portion 20 and the movable-side conductor portion 10 maintain a state in which they are electrically connected to each other through the movable rod portion 30.

On the other hand, when switching to the blocking state as shown in FIG. 2, when the operating shaft 31 pulls the movable rod part 30, the main contact point 32 and the finger contact point 22 are first separated, and then the fixed arc contact 24 ) And the moving arc point 34 are separated.

At this time, when the fixed arc contact 24 and the movable arc contact 34 are separated, an arc is generated. This process is well illustrated in FIGS. 3 and 4.

SF ₆ gas is used as an insulating gas to block the arc generated for this reason.

SF ₆ is stored in the pressure chamber 42 and then compressed by the piston 45 as the movable rod part 30 moves to the movable side conductor part 20.

Then, when the compressed SF ₆ gas becomes a predetermined pressure or more, it moves to the heat chamber 44 and is injected into the nozzle unit 50.

At this time, the nozzle unit 50 is formed in a form surrounding the movable arc contact 34 of the movable rod unit 30.

In addition, the nozzle unit 50 includes a main nozzle 52 and an auxiliary nozzle 54, SF ₆ gas is injected into the gap between the main nozzle 52 and the auxiliary nozzle 54.

In addition, the SF ₆ gas accumulated in the heat chamber 44 is sprayed to extinguish the arc through the nozzle unit 50. The SF ₆ gas injected due to the arc generated during blocking is in a high temperature and high pressure state and is fixed. Supersonic flow is generated by the conductor portion 20 and the movable side conductor portion 10.

In this case, since the high-temperature SF ₆ gas has a rapid drop in insulation performance, the gas with low insulation performance may cause insulation breakdown between the ground and the phase.

Here, the exhaust paths of the high-temperature, high-pressure SF ₆ gas are shown in FIGS. 3 and 4.

For example, both the fixed-side conductor portion 10 and the movable-side conductor portion 20 are provided with cylindrical conductors 110 and 210 and internal conductor pipes 120 and 220 connected therein, resulting in high temperature and high pressure SF ₆ caused by arcing. Gas is moved along the inside of the inner conductor pipe (120,220) to the bottom surface (112,212) of the conductor (110,210) and then moves along the outside of the inner conductor pipe (120,220) to have a path discharged to the outside of the conductor (110,210) can do.

At this time, in order to sufficiently cool the high temperature and high pressure SF ₆ gas, there is a method of extending the contact length by lengthening the length of the inner conductor pipes 120 and 220. However, when the inner conductor pipes 120 and 220 are lengthened, the SF ₆ gas cooling effect is obtained. Although it can be brought about, a problem occurs in which the discharge time is delayed, and if the discharge time is delayed, the possibility of blocking failure increases when performing the second blocking, so the contact length cannot be extended indefinitely.

Accordingly, diffusion holes 130 and 230 may be provided in the inner conductor pipes 120 and 220 to solve this.

That is, when the high-temperature, high-pressure SF ₆ gas is generated and exhausted due to the arc, the gas close to the diffusion holes 130 and 230 passes through the diffusion holes 130 and 230 to induce exhaustion.

Therefore, in the periphery of the diffusion holes 130 and 230, vortices are generated around the diffusion holes 130 and 230 due to the gas flow due to the small discharge size of the diffusion holes 130 and 230, and thereby SF around the outer walls of the inner conductor pipes 120 and 220. ₆ Gas is collected and cooled, resulting in exhaust.

This may bring the SF ₆ gas cooling effect by extending the contact length by lengthening the inner conductor pipes 120 and 220, but not increasing the length of the inner conductor pipes 120 and 220 for the prior art having a problem in that the discharge time is delayed. This means that the SF ₆ gas can be cooled without it.

In addition, gases that do not pass through the diffusion holes 130 and 230 reach the bottom surfaces 112 and 212 of the conductors 110 and 210 along the inner surfaces of the inner conductor tubes 120 and 220, and after reaching the bottom surfaces 112 and 212, the inner conductor tubes 120 and 220 ) And is discharged along the conductors 110 and 210.

On the other hand, in order to prevent backflow after the insulating gas in the pressure chamber 42, that is, SF ₆ gas is conveyed to the heat chamber 44, a check valve of the form shown in FIG. In the conventional structure, the flap FL capable of opening and closing the through hole is hinged to the valve body BD, and the torsion spring is mounted on the hinge shaft HN to receive elastic force in the direction in which the flap FL always closes. .

However, the flap (FL) method has a problem of causing safety and equipment accidents due to SF ₆ gas conveyance failure, as the airtightness decreases when used for a long time, and the elastic force of the torsion spring decreases to cause a backflow phenomenon.

To solve this, in the present invention, as shown in Figure 5 (b), the diaphragm (DF) is installed.

The diaphragm (DF) according to the present invention is screwed in a direction passing through the partition wall (WAL) partitioning the pressure chamber 42 and the heat chamber 44 to constitute a flow path (PASS) so that SF ₆ gas can flow. The cylinder 300, the flange 310 formed at the exposed end of the heat chamber 44 of the cylinder 300, and the cylinder 300 provided at the center of the end face of the cylinder 300 on which the flange 310 is formed are provided with the cylinder 300 ) The fixed disk 330 fixed by a plurality of ribs 320 protruding from the inner circumferential surface, the tapered portion 340 inclined on the inner circumferential surface of the end portion of the cylinder 300 on which the flange 310 is formed, and the flange ( 310) is in close contact with the reverse flow prevention plate 350 for opening and closing the flow path (PASS), and through the center of the reverse flow prevention plate 350 and the fixed disk 330 is fixed to the screw on the fixed disk 330 A fixed rod 360, a head portion 370 integrally fixed to an end portion of the fixed rod 360, and fitted to the fixed rod 360, the reverse flow The elastic round piece 380 is disposed between the finger plate 350 and the head portion 370 to elastically press the backflow prevention plate 350, and is fitted to the fixed rod 360 and the backflow prevention plate 350 and It includes a coil spring 390 disposed between the head portion 370.

At this time, the tapered portion 340 is a means for allowing the SF ₆ gas of the pressure chamber 42 to escape more smoothly when conveyed to the heat chamber 44.

In addition, since the reverse flow prevention plate 350 is elastically pressurized while one coil spring 390 and one elastic round piece 380 are complementary to each other, even if the spring is used for a long time, a decrease in airtightness due to a decrease in the elastic force of the spring is observed. Can be prevented. That is, even if the function of the coil spring 390 is somewhat deteriorated, since the elastic round piece 380 reinforces instead of it, the backflow prevention function is always maintained accurately.

Therefore, it is possible to completely eliminate the problems that arise when using the existing flap type check valve.

On the other hand, since the SF ₆ gas expands under a very large pressure at the same time as the arc is generated, the conductors 110 and 210 on both sides deteriorate due to the impact, so that a problem of shortening life due to cracks, erosion, etc. occurs during long use.

In order to improve this, in the present invention, as illustrated in FIG. 6, the movable side diffusion buffer 400 and the fixed side diffusion buffer 500 of the double elastic buffer structure are further provided.

At this time, the movable-side diffusion buffer 400 and the fixed-side diffusion buffer 500 differ only in the diameters of the inner diameters to be fitted, and the rest of the configuration is the same.

That is, the movable side diffusion buffer 400 is fitted into a shaft inserting cylinder (TNG) provided to install the operation shaft 31, and the first buffer cup 410 with an open end facing the pressure chamber 42 is opened. ), The second buffer cup 420 fitted to the shaft insertion tube (TNG) and fitted to the end of the first buffer cup (410), and the first, second, fitted to the shaft insertion tube (TNG) The first buffer spring 430 disposed between the buffer cups 410 and 420 and the shaft insertion cylinder (TNG), one end fixed to the inner wall surface of the conductor 110 and the other end of the second buffer cup 420 It includes a second buffer spring (440) fixed to the end of the.

Thus, by having a double elastic buffer structure by the two first and second buffer springs 430 and 440, the expansion pressure of the SF ₆ gas rapidly expanding under a large pressure can be instantaneously elastically buffered, and through this, the conductor It is suppressed that the inner wall surface of 110 is cracked, deteriorated and shortened.

In particular, the first buffer cup 410 is preferably formed in a funnel shape, and is configured to receive the SF ₆ gas rapidly expanding therethrough.

In addition, the first buffer cup 410 and the second buffer cup 420 are formed with relatively large hole-shaped through holes 412 and 422 to allow SF ₆ gas to escape quickly, and the through holes 412 and 422 SF ₆ gas can be smoothly escaped to the diffusion hole (130).

In addition, assembling of the first and second buffer cups 410 and 420 has an inner and outer circumferential surface of the mutual assembly stage, that is, the first buffer cup 410 has an outer peripheral surface, and the second buffer cup 420 has 2 pitches of threads on the inner peripheral surface. It is formed, and after 2 pitches after screw assembly, all are thread-free, so it is possible to assemble while sliding while preventing departure. By doing so, it can be assembled so that it can slide smoothly without a separate fastener.

And, the fixed side diffusion buffer 500 is fitted to a contact bar (BNG) for fixing the fixed arc contact 24, the third buffer cup 510 with an open end to the heat chamber 44, A fourth buffer cup 520 fitted to the contact rod BNG and fitted to an end of the third buffer cup 510; and the third and fourth buffer cups 510,520 fitted to the contact rod BNG. A third buffer spring 530 disposed between, and fitted to the contact bar BNG, one end fixed to the inner wall surface of the conductor 210 and the other end fixed to an end of the fourth buffer cup 520 It includes a fourth buffer spring (540).

Thus, by having a double elastic buffer structure by two third and fourth buffer springs 530 and 540, the expansion pressure of SF ₆ gas rapidly expanding under a large pressure can be instantaneously elastically buffered, and through this, the conductor It is suppressed that the inner wall surface of 210 is cracked, deteriorated and shortened.

In particular, the third buffer cup 510 is preferably formed in a funnel shape, and is configured to receive the SF ₆ gas rapidly expanding therethrough.

In addition, the third buffer cup 510 and the fourth buffer cup 520 are formed with relatively large hole-shaped through holes 512 and 522 to allow SF ₆ gas to escape quickly, and the through holes 512 and 522 The SF ₆ gas can smoothly escape into the diffusion hole 230.

In addition, the assembling of the third and fourth buffer cups 510 and 520 has an inner and outer circumferential surface of the mutual assembly stage, that is, the third buffer cup 510 has an outer peripheral surface, and the fourth buffer cup 520 has two pitches of threads on the inner peripheral surface. It is formed, and after 2 pitches after screw assembly, all are thread-free, so it is possible to assemble while sliding while preventing departure. By doing so, it can be assembled so that it can slide smoothly without a separate fastener.

Here, the movable-side diffusion buffer 400 and the fixed-side diffusion buffer 500 should be molded into a special molding composition having corrosion resistance and heat resistance characteristics.

In this case, since the arc is raised to a very high temperature at the point of occurrence, it is very instantaneous, so there is no persistence, so the movable side diffusion buffer 400 and the fixed side diffusion buffer 500 installed at a distance from the arc occurrence point have high strength. It may be molded from heat-resistant plastic.

To this end, in the present invention, 30% by weight of dimethylpolysiloxane, 2.5% by weight of Mn-Cr alloy powder, 5% by weight of boron nitride, and mixed solution of 3-hydroxytoluene and meta-cresol in a weight ratio of 1: 1 By forming a molding composition composed of weight%, molybdenum 2.5% by weight, CaF ₂ 5% by weight, and the remaining PTFE (polytetrafluoroethylene) resin, the movable side diffusion buffer 400 and the fixed side diffusion buffer 500 are realized. .

At this time, dimethylpolysiloxane is composed of a heat-resistant siloxane bond (Si-O-Si) and an organic methyl group, and has strong adhesion, heat resistance, and thermal oxidation stability, thereby enhancing binding strength between components to realize high strength.

In addition, the Mn-Cr alloy is added to rapidly increase the erosion resistance by densifying the tissue while suppressing segregation, and boron nitride is added to suppress thermal deformation while enhancing heat resistance and stabilization.

In addition, the mixed solution in which 3-hydroxytoluene and meta-cresol are mixed in a weight ratio of 1: 1 has excellent function of anchoring binding components between bindings, and is added to increase moldability and realize molding stability and shape retention.

In addition, molybdenum is added to enhance wear resistance, CaF ₂ is added to act as a solid lubricant at high temperatures, and PTFE resins increase the chemical resistance, non-adhesiveness, antifouling properties, heat resistance, and friction properties while increasing the binding properties between materials. It is added to strengthen.

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10: movable side conductor portion 20: fixed side conductor portion
22: finger contact 24: fixed arc contact
30: movable rod section 32: main contact
34: movable arc contact 42: pressure chamber
44: heat chamber

Claims (1)

A movable side conductor portion 10, a fixed side conductor portion 20, and a movable rod portion 30 moving between them to switch between an input state and a blocking state; The movable-side conductor portion 10 or the fixed-side conductor portion 20 includes a cylindrical conductor 110 and 210 having a bottom surface, and an inner conductor pipe 120 and 220 connected to the interior of the conductors 110 and 210; The movable rod part 30 in the GIS circuit breaker including a pressure chamber 42 and a heat chamber 44 for transporting SF ₆ gas, and an operation shaft 31 for flowing the movable rod part 30 ;
A diaphragm DF is installed on a partition wall WAL that partitions the pressure chamber 42 and the heat chamber 44, but the diaphragm DF is screwed in a direction passing through the partition wall WAL, resulting in SF ₆ The cylinder 300 constituting the flow path PASS to allow gas to flow, the flange 310 formed at the exposed end of the heat chamber 44 of the cylinder 300, and the cylinder 300 formed with the flange 310 ) Is provided in the center of the inner end surface of the fixed body 330 fixed by a plurality of ribs 320 protruding from the inner circumferential surface of the cylinder 300, and the flange 310 is formed inclined to the inner circumferential end of the cylindrical body 300 The machined taper portion 340 and the counterflow preventing plate 350 that are in close contact with the flange 310 to open and close the flow path PASS, and penetrate the centers of the countercurrent preventing plate 350 and the fixed circular plate 330. The fixed rod 360 is screwed onto the fixed disk 330, the head portion 370 integrally fixed to the end of the fixed rod 360, and The elastic rod piece 380 is fitted between the fixed rod 360 and disposed between the backflow prevention plate 350 and the head portion 370 to elastically pressurize the backflow prevention plate 350, and the fixed rod 360 And a coil spring 390 interposed between the reverse flow prevention plate 350 and the head portion 370;
Inside the inner conductor pipe 120 of the movable-side conductor part 10, a movable-side diffusion buffer 400 is further installed, and the fixed-side diffusion inside the inner conductor pipe 220 of the fixed-side conductor part 20 The buffer 500 is further installed,
The movable side diffusion buffer 400 is fitted into a shaft inserting cylinder (TNG) provided to install the operating shaft 31 and the first buffer cup 410 with an open end facing the pressure chamber 42 , A second buffer cup 420 fitted to the shaft insertion tube (TNG) and fitted to an end of the first buffer cup 410, and the first and second buffer cups fitted to the shaft insertion tube (TNG) The first buffer spring 430 disposed between (410,420) and the shaft insertion cylinder (TNG), one end fixed to the inner wall surface of the conductor 110 and the other end of the second buffer cup 420 It includes a second buffer spring 440 fixed to the end;
The fixed-side diffusion buffer 500 is fitted into a contact rod (BNG) for fixing the fixed arc contact 24 installed at the inner center of the fixed-side conductor part 20, and the end facing the heat chamber 44 is opened. The third buffer cup 510, the fourth buffer cup 520 fitted to the contact rod BNG and fitted to the end of the third buffer cup 510, and the contact rod BNG A third buffer spring 530 disposed between the third and fourth buffer cups 510 and 520, and fitted to the contact bar BNG, one end being fixed to the inner wall surface of the conductor 210 and the other end being the fourth It includes a fourth buffer spring 540 fixed to the end of the buffer cup 520;
The outer circumferential surface of the first buffer cup 410 and the inner circumferential surface of the second buffer cup 420 coupled thereto are each formed with only 2 pitches of threads, and the rest are made up of minja, and after 2 pitches after screw assembly, separation is prevented. Configured to be slidable;
On the outer circumferential surface of the third buffer cup 510 and the inner circumferential surface of the fourth buffer cup 520 coupled thereto, only 2 pitches of threads are formed, and the rest is composed of folks. GIS circuit breaker with easy operation and insulated gas backflow prevention function characterized by being slidable.

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