KR20170086368A

KR20170086368A - Double motion drivinig unit in insulated switchgear

Info

Publication number: KR20170086368A
Application number: KR1020160006124A
Authority: KR
Inventors: 최명; 김견우
Original assignee: 엘에스산전 주식회사
Priority date: 2016-01-18
Filing date: 2016-01-18
Publication date: 2017-07-26

Abstract

The present invention relates to a double drive device for a gas insulated switchgear device which improves the structure of a dual drive device for moving the first and second movable arc contactors in the opposite direction, thereby enhancing the mechanical durability of the dual drive device.
The present invention provides a power transmission device comprising: a first movable part driven by a power transmission mechanism and linearly moving in the same direction as a power transmission mechanism; A motion switching device driven by the first moving part to generate a linear motion in a direction opposite to the first moving part; And a second movable part driven by the motion switching device and linearly moving in a direction opposite to the first movable part, wherein the motion switching device is driven by the first movable part, A dual fork in which a linear motion of the pull bar is converted into a rotational motion and a pinion is formed at the other end in association with the pull bar, Wherein the dual fork is coupled to the pinion of the dual fork so as to be able to switch to linear motion in the direction opposite to the linear motion of the pool bar.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a double-

The present invention relates to a gas insulated switchgear, and more particularly, to a gas insulated switchgear having improved mechanical durability of a motion switching device by improving the configuration of a motion switching device for moving the first and second movable arc contactors in the opposite direction To a dual drive system.

The gas insulated switchgear is a main protection device for ultra-high voltage power equipment installed in a power station or a substation. It is installed on the circuit between the power source side and the load side of the electric system and artificially opens or closes the circuit in the normal current state, It has a function to protect the power system and load equipment by safely shutting off the current by detecting the abnormal current when it occurs.

The gas insulated switchgear is advantageous in that it can be used repeatedly after it has been manually or automatically reset after the cutoff operation, unlike a fuse-operated circuit breaker in which the operation fuse must be replaced for re-input after the cutoff operation.

The gas insulated switchgear according to the prior art has a configuration in which the movable primary contactor is first disconnected from the fixed primary contactor in the closing operation and then the movable arc contactor is separated from the fixed arc contactor and when the movable arc contactor is separated from the fixed arc contactor The arc generated between the stationary arc contactor and the movable arc contactor is configured to be quickly extinguished by the SOF gas injected through the nozzle, for example, SFF gas having excellent insulating properties.

In the gas insulated switchgear according to the related art constructed as described above, it is known that it is advantageous to separate the movable arc contactor as fast as possible from the fixed arc contactor in order to prevent the arc cutoff failure.

However, in order to improve the speed of separating the movable arc contactor from the fixed arc contactor, it is necessary not only to increase the output of the power source for operating the movable main contactor and the movable arc contactor, but also to increase the output of the power source There is a problem that the manufacturing cost of the gas insulated switchgear must be increased.

In order to solve this problem, in the gas insulated switchgear according to the related art, the fixed arc contactor is designed so as to be movable, and is configured to move in a direction opposite to the moving direction of the movable arc contactor during the cutoff operation, A double-driving device of a gas insulated switchgear has been proposed which improves the relative cut-off speed between the arc contacts.

1 is a cross-sectional view of a dual drive device of a gas insulated switchgear according to the related art in which a stationary arc contactor can be operated. Referring to FIG. 1, a dual drive device of a gas insulated switchgear according to the related art, A first movable portion 10 driven by the power transmitted from the transmission mechanism and linearly moving in the same direction as the power transmission mechanism, a second movable portion 10 driven by the first movable portion 10 to generate a linear motion in a direction opposite to the first movable portion, And a second movable portion 20 driven by the switching device 30 and performing linear motion in the opposite direction to the first movable portion 10 driven by the motion switching device 30. [

The first movable portion 10 comprises: A cylinder rod 12 which is a power transmission mechanism coupled to a known power source not shown and linearly moves along the longitudinal direction of the first fixed cylinder 11, A compression cylinder 13 which is linearly moved in the same direction as the cylinder rod 12 in the first fixed cylinder 11 by being engaged with the front end of the cylinder rod 12, A movable primary contactor 16 formed on the outer circumferential surface of the compression cylinder 13 at its front end and a fixed primary contactor 16 fixed to the compression cylinder 13 to move the compression cylinder 13 and the compression cylinder 13 in accordance with the movement of the cylinder rod 12. [ And a nozzle 17 for linearly moving in the same direction as the one movable arc contact 14 and injecting compressed soot gas from the compression chamber 15 of the compression cylinder 13 in the blocking operation.

The second movable portion 20 includes: Is supported to be linearly moved by a guide (35) fixed along the axial direction of the gas insulated switchgear and fixed to a second fixed cylinder (21) arranged so as to be spaced from the first fixed cylinder (11) 14) and a second movable arc contact (24) which moves to a position where it is contacted or separated.

Here, the reference numeral " 26 " is a fixed primary contactor formed on the inner peripheral surface of the second fixed cylinder 21 which is contacted or separated by the movable primary contactor 16. [

The motion switching device (30) comprises: A pull bar 32 coupled to the support ring and linearly moving in the same direction as the cylinder rod 12 and a pull bar 32 coupled to the pull bar 32, A dual fork 33 for converting the linear motion of the first fork 32 into a rotational motion and a second movable arc contactor 33 for converting the rotational motion of the dual fork 33 into a linear motion opposite to the linear motion of the full bar 32 And a pin housing (34) coupled to the pin housing (24).

More specifically, the pull bar 32 is coupled to the cylinder rod 12, which is a power transmission mechanism, via the support ring 31, the nozzle 17 and the compression cylinder 13, Moving in the same direction is possible.

The dual forks 33 are rotatably provided with respect to the second fixed cylinder 21 through a shaft 33a and are fixed to the pool bar 32 at one end of the dual forks 33 located on the pool bar 32 side. And a pin 33p inserted into the slot 34s of the pin housing 34 is formed at the other end of the dual fork 33 located on the pin housing 34 side. Respectively.

When the pin 32p is inserted into the slot 33s of the dual fork 33 according to the linear movement of the pull bar 32, the pin 32p rotates the dual fork 33 to rotate the pull bar 32 The linear motion is converted into rotational motion through the dual forks 33. [

At the same time, the pin housing 34 is coupled to the other end of the second movable arc contact 24 inserted and guided in the guide 35 fixed to the second fixed cylinder 11, The rotational movement of the pin housing 33p converts the pin housing 34 into linear motion in a direction opposite to the linear motion of the pull bar 32. [

The operation of the dual drive system of the conventional gas insulated switchgear constructed as above will be described with reference to FIGS. 1 to 2F.

In the description of the directions of FIGS. 1 to 2F, for the sake of convenience of explanation, the lower direction will be described as a left direction and the upper direction as a right direction in the drawing, and FIGS. 2A to 2F will be described with reference to FIGS. Will be described along the directions as shown.

In the gas insulated switchgear, when an external power source (not shown) is driven in order to cut off the circuit in response to the generation of the abnormal current, the cylinder rod 12, the compression cylinder 13, the movable main contactor 16, The arc contact 14 and the nozzle 17 also start to move in the left direction so that the compression cylinder 13 compresses the soot gas in the compression chamber 15 and the movable primary contact 16 and the first movable arc The contactor 14 begins to separate from the fixed primary contact 26 and the second movable arc contact 24 (see Figure 2a)

2a, the pull bar 32 coupled to the nozzle 17 through the support ring 31 is also linearly moved in the left direction, but the pin 32p of the pull bar 32 is still in the dual fork 33, The rotation of the dual forks 33 does not occur and the second movable arc contact 24 is still kept in a stopped state (see Fig. 2B)

Thereafter, when the pull bar 32 further moves to the left and the pin 32p is inserted into the slot 33s of the dual fork 33, the dual fork 33 rotates clockwise about the shaft 33a And the pin 33p fixed to the other end of the dual fork 33 also starts to rotate clockwise (see FIG. 2C).

Thereafter, when the pull bar 32 is further moved to the left, the pin 33p of the dual fork 33 is inserted into the slot 34s formed in the pin housing 34, and the second operation coupled to the pin housing 34 Since the arc contact 24 is slidably supported by the guide 35 fixed to the second fixed cylinder 21, the pin 33p rotating clockwise rotates the pin housing 34 in the right direction in the drawing So that the second movable arc contact 24 coupled to the pin housing 34 starts to move in the opposite direction, i.e., rightward direction, with the first movable arc contact 14 (see Fig. 2 (d)).

Thereafter, when the pull bar 32 continues to move further leftward by the cylinder rod 12, the movable main contact 16 is first disconnected from the fixed main contact 26, and then the first and second movable arc contactors The first and second movable arc contactors 14 and 24 are separated from each other by moving in opposite directions, that is, leftward and rightward directions. When the first and second movable arc contactors 14 and 24 are separated from each other, The arc generated between the first and second movable arc contactors 14 and 24 is rapidly extinguished because the compressed lobe gas supplied from the compression cylinder 13 is already injected from the nozzle 17 and is rapidly extinguished, The pin 32p of the pull bar 32 is disengaged from the slot 33s of the dual fork 33 so that the linear movement of the pull bar is no longer switched from dual forks to rotary motion.

The first and second movable arc contactors 14 and 24 further move to the left side further by the cylinder rod 12 even after the first and second movable arc contactors 14 and 24 are separated from each other, (See Fig. 2F).

Since the first and second movable arc contactors 14 and 24 move in opposite directions during the closing operation in the arc extinguishing process of the arc, compared with the conventional art in which only one arc contactor is operated, Since the cut-off speed between the contacts 14 and 24 is two times faster, it is possible to effectively achieve the arc extinguishing which occurs during the cut-off operation without particularly increasing the output of the power source.

In the dual drive system of the gas insulated switchgear according to the prior art having such a configuration and operation, the dual fork 33 is the most essential component part of the double drive system of the gas insulated switchgear, but the IEC (International Electrotechnical Commission: It is also the part that represents the weakest test result in the mechanical durability test for the "M2" class circuit breaker specified in the International Electrotechnical Commission.

In more detail, the IEC classifies the mechanical durability of circuit breakers into the "M1" class and the "M2" class.

The "M1" class circuit breaker is a general mechanical durability circuit breaker with 2,000 mechanical open / close tests, whereas the "M2" class circuit breaker is a mechanical durability enhanced circuit breaker with 10,000 mechanical open / close tests Is applied.

The "M2" class circuit breakers are designed to require only limited maintenance and are provided with special service requirements that require frequent operation of the circuit breaker.

The "M2" class circuit breakers are always selected for ultra high voltage circuit breakers, such as gas insulated switchgear, according to customer requirements.

However, in the gas insulated switchgear having the structure of the pin housing 34 in which the pin 33p of the dual fork 33 and the pin 33p are accommodated, as shown in Fig. 1, the pin 33p of the dual fork 33, And the inner wall forming the slot 34s of the pin housing 34 so that the pin 33p of the dual fork 33 and the pin housing 34 (See "A" part in Fig.

As shown in FIG. 5, the simulation result of the conventional gas insulated device according to the prior art shows that the maximum value of the von Meister stress applied to the pin 33p of the dual fork 33 is 500 MPa, Which exceeds the maximum allowable stress of 350 MPa on the pin 33p of the dual fork 33 made of stainless steel.

Therefore, during the 10,000 opening and closing operations during the mechanical durability test of the "M2" class, the pin 33p is broken and fails to pass the test of the "M2" class.

As a result, according to the results of the "M1" and "M2" tests, the pin 33p of the dual fork 33 having such a configuration and the pin housing 34 accommodating the pin 33p can be opened and closed up to 2,500 times The test was suitable for use in a circuit breaker of class "M1 " within the allowable durability range, but with respect to the number of tests beyond that, breakage of the pin 33p of the dual fork 33 due to accumulated fatigue occurred, M2 "class circuit breakers. &Lt; / RTI >

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a dual drive unit of a gas insulated switchgear with a new structure having improved durability so as to pass the test of "M2" class considered as the most difficult test in the field of ultra- The present invention has been made in view of the above problems.

In order to achieve the above object, the present invention provides a power transmission device comprising: a first movable part driven by a power transmission mechanism and linearly moving in the same direction as a power transmission mechanism; A motion switching device driven by the first moving part to generate a linear motion in a direction opposite to the first moving part; And a second movable part driven by the motion switching device and linearly moving in a direction opposite to the first movable part, wherein the motion switching device is driven by the first movable part, A dual fork in which a linear motion of the pull bar is converted into a rotational motion and a pinion is formed at the other end in association with the pull bar, Wherein the rack is coupled to the pinion of the dual fork so as to be able to switch to a rectilinear motion in a direction opposite to the rectilinear motion of the pool bar.

Here, the first movable portion may include a first movable arc contactor, the second movable portion may include a second movable arc contactor, and the rack may be coupled to the second movable arc contactor.

The gas insulated switchgear further comprises a support plate coupled to the inside of the enclosure, and the support plate may have a first guide hole through which the rack is inserted and guided.

In addition, the dual forks may be rotatably installed in a support block coupled to the support plate, and the support block may be formed with grooves guided by the rack.

Further, a second guide hole for guiding the pull bar may be formed on the support plate.

Since the double drive system of the gas insulated switchgear according to the present invention is always in a state in which the rack and the pinion are meshed with each other, the shock generated between the rack and the pinion during the closing and shutting operation of the gas insulated switchgear is minimized, And the pinion are minimized.

Further, since the rotational force exerted by the pinion is uniformly dispersed in the respective portions of the teeth forming the pinion and rack, the double drive device according to the present invention having a rack-and-pinion structure can be applied to a conventional pin- The mechanical stress distribution can be uniformly achieved.

Therefore, the dual drive system of the gas insulated switchgear according to the present invention prevents locally excessive stress from being exerted on the rack and pinion, which is a motion switching device of the dual drive system, when the gas insulated switchgear is opened or closed, The durability of the dual drive system is improved.

1 is a longitudinal sectional view of a gas insulated switchgear to which a double drive device according to the prior art is applied.
FIGS. 2A to 2F are operation diagrams of a dual drive device of a gas insulated switchgear according to the prior art.
3 is a longitudinal sectional view of a gas insulated switchgear to which a dual drive device according to the present invention is applied.
4A to 4F are operation diagrams of a dual drive device of a gas insulated switchgear according to the present invention.
FIG. 5 is an exemplary view illustrating a Poisson midscale stress distribution and a stress value of a dual drive system of a gas insulated switchgear according to the prior art.
6A is an exemplary view illustrating the von Meister stress distribution of the dual drive system of the gas insulated switchgear according to the present invention.
6B is a diagram showing the stress value distribution according to FIG. 6A.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, It will be understood by those of ordinary skill in the art that the invention may be practiced and carried out in various other manners without departing from the spirit and scope of the invention.

Hereinafter, a dual drive system for a gas insulated switchgear according to the present invention will be described with reference to FIG.

Referring to FIG. 3, the dual drive system of the gas insulated switchgear according to the present invention includes a first movable part 100 driven by the power transmitted from the power transmission mechanism and linearly moving in the same direction as the power transmission mechanism, A motion switching device 300 which is driven by the motor 100 to generate a linear motion in a direction opposite to the first moving part 100 and a motion switching device 300 which is driven by the motion switching device 300 to move in a direction opposite to the first moving part 100 And a second moving part 200 that linearly moves.

First, the first movable part 100 includes: A cylinder rod 120 which is a power transmission mechanism coupled to a known power source (not shown) and linearly moves along the longitudinal direction of the first fixed cylinder 110, a cylinder rod 120 coupled to the cylinder rod 120, A compression cylinder 130 that linearly moves in the same direction as the cylinder rod 120 in the first fixed cylinder 110 and a second compression cylinder 130 that is coupled to the front end of the cylinder rod 120 and linearly moves in the same direction as the cylinder rod 120 in the first fixed cylinder 110 A movable primary contactor 160 formed on the outer circumferential surface of the distal end of the compression cylinder 130 and a movable contactor 160 fixed to the compression cylinder 130 to move the compression cylinder 130 and / And a nozzle 170 that linearly moves in the same direction as the first movable arc contactor 140 and injects compressed soot gas from the compression chamber 150 of the compression cylinder 130 during the shutoff operation.

The second movable part 200 includes: Is supported by a guide (350) fixed along the axial direction of the gas insulated switchgear and fixed to a second fixed cylinder (210) arranged so as to be spaced apart from the first fixed cylinder (110) 140 to move to a position to be contacted or disengaged.

Reference numeral 260 denotes a fixed primary contactor formed on the inner peripheral surface of the second fixed cylinder 210 which is contacted or separated by the movable primary contactor 160. [

The motion switching device (300) comprises: The dual fork 330 and the pin housing 34 of the prior art are improved in that the dual fork 330 and the pin housing 34 are formed integrally with the pull bar 320, And a rack 340 interlocked with the pinion of the dual fork is provided to convert the rotational motion of the dual forks 330 into linear motion in the opposite direction to the linear motion of the pull bars 320. [

The movement switching device 300 includes a support ring 310 fixed to the nozzle 170 and a pull bar 320 coupled to the support ring 310 and linearly moving in the same direction as the cylinder rod 120. [ A dual fork 330 for converting linear motion of the pull bar 320 into rotational motion in cooperation with the pull bar 320 and a dual fork 330 for rotating the dual forks 330 in a direction opposite to the rectilinear motion of the pull bar 320 And a rack 340 for switching to a rectilinear motion of FIG.

The pull bar 320 is coupled to the cylinder rod 120 which is a power transmission mechanism via the support ring 310, the nozzle 170 and the compression cylinder 130 so that the pull bar 320 is moved in the same direction as the cylinder rod 120 It is possible.

The dual forks 330 are rotatably mounted on the support block 370 by a shaft 330a supported on a support block 370 fixed to a support plate 360 of a second fixed cylinder 210, The block 370 is formed with a groove H in which the rack 340 is guided.

A slot 330s is formed at one end of the dual fork 330 located at the side of the pull bar 320 and a pin 320p fixed to the pull bar 320 is inserted therein. A pinion 330p is coupled to the rack 340 at the other end of the fork 330. [

The other end of the rack 340 is fixed to the second movable arc contact 240 and the other end of the second fixed cylinder 210 moves inside the enclosure of the gas insulated switchgear, And is inserted and guided in a first guide hole 360h1 formed in the support plate 360 coupled to the inner surface of the second fixed cylinder 210. More specifically,

Therefore, the rack 340 can be stably guided by the first guide hole 360h1 together with the groove H. [

The second guide hole 360h2 for guiding the pull bar 320 is preferably formed on the support plate 360 for stable movement of the pull bar 320. [

In the apparatus for switching motion of the dual drive apparatus of the gas insulated switchgear according to the present invention, the pull bars 320 may be configured as a pair as in the conventional case. However, 320 may be provided.

The operation of the dual drive system of the gas insulated switchgear according to the present invention will now be described with reference to FIGS. 3 to 4F.

3 to 4f, the lower direction will be described as a left direction and the upper direction as a right direction in the drawing shown in FIG. 3 for convenience of explanation, and FIGS. 4A to 4F will be described with reference to FIGS. Will be described along the directions as shown.

When an external power source (not shown) is driven in order to cut off the circuit in response to the generation of the abnormal current in the gas insulated switchgear, the cylinder rod 120, the compression cylinder 130, the movable main contactor 160, The arc contact 140 and the nozzle 170 also start moving in the left direction so that the compression cylinder 130 compresses the soot gas in the compression chamber 150 and the movable main contact 160 and the first movable arc The contactor 140 begins to separate from the fixed primary contact 260 and the second movable arc contact 240 (see FIG. 4A)

3A, the pull bar 320 coupled to the nozzle 170 through the support ring 310 is moved linearly in the left direction, but the pin 320p of the pull bar 320 is still in contact with the dual forks 330, The rotation of the dual forks 330 does not occur and the second movable arc contactor 240 is still in a stopped state (see FIG. 4B) since it is not inserted into the slot 330s of the second movable arc contact 330. Accordingly,

Thereafter, when the pull bar 320 moves further to the left and the pin 320p is inserted into the slot 330s of the dual fork 330, the dual fork 330 rotates clockwise about the axis 330a And the pinion 330p formed at the other end of the dual fork 330 also starts to rotate in the clockwise direction (see FIG. 4C).

Thereafter, when the pull bar 320 moves further to the left, the pinion 330p of the dual fork 330 is engaged with the rack 340 and the second movable arc contact 240 coupled to the rack 340 is engaged with the second The pinion 330p rotating in the clockwise direction moves the rack 340 in the right direction in the figure so that the rack 340 rotates in the clockwise direction, The second movable arc contact 240 coupled to the first movable arc contact 140 begins to move in a direction opposite to the first movable arc contact 140,

Thereafter, when the pull bar 320 continues to move further leftward by the cylinder rod 120, the movable primary contactor 160 is first disconnected from the fixed primary contactor 260, and then the first and second movable arc contactors The first and second movable arc contactors 140 and 240 are separated from each other by moving in opposite directions, that is, leftward and rightward directions, respectively. When the first and second movable arc contactors 140 and 240 are separated from each other, The arc generated between the first and second movable arc contactors 140 and 240 is rapidly extinguished because the compressed lobe gas supplied from the compression cylinder 130 has already been injected from the nozzle 170, The pin 320p of the pull bar 320 is disengaged from the slot 330s of the dual fork 330 so that the linear movement of the pull bar 320 is no longer converted to rotational movement in the dual fork 330. 4e)

After the first and second movable arc contacts 140 and 240 are separated from each other, the cylindrical rod 120 further moves further to the left by the cylinder rod 120 so that the first and second movable arc contacts 140 and 240 are separated from each other. (See Figure 4f).

Since the rack 340 and the pinion 330p are always in mesh with each other, the movement switching device 300 of the dual drive device of the gas insulated switchgear having the above-described structure is capable of switching on and off the gas insulated switchgear. The shock generated between the rack 340 and the pinion 330p is minimized during the shutting operation, so that the stress accumulated between the rack 340 and the pinion 330p is also minimized.

Also, since the rotational force exerted by the pinion 330p as shown in FIG. 6A is evenly dispersed in each portion of the teeth forming the pinion 330p and the rack 340, the rack-and-pinion structure The present invention provides a dual drive system that uniformly distributes mechanical stresses as compared to a dual drive system having a conventional pin-and-pin housing structure.

Table 1 shows test results of the dual drive system of the gas insulated switchgear according to the present invention. As a result of the simulation analysis, the maximum value of the von Meister stress applied to the pinion 330p of the dual fork 330 and the rack 340 is 300 MPa, It is found that the stress of 350 MPa, which is the allowable range of the stress defined in the test of the "M2" class, is satisfied.

Allowable Stress Range in M2 Test (MPa / Stainless Steel) Simulation stress value (MPa) Reference Conventional technology 350 500 5 Invention 350 300 6A and 6B

As shown in Table 1, the double-driving apparatus of the gas insulated switchgear according to the present invention is installed at the connection point of the dual forks 330 compared with the double driving apparatus of the gas insulated switchgear according to the present invention, The maximum stress to be applied is reduced by 200 MPa.

Therefore, if the double driving device according to the present invention is applied to the gas insulated switchgear, the opening and closing operation of the gas insulated switchgear is guaranteed at least 10,000 times, so that it can pass the "M2" class test of the circuit breaker specified by IEC have.

In the meantime, although the dual drive device is described as being applied to the gas insulated switchgear in connection with the above-mentioned preferred embodiment of the present invention, it will be apparent to those skilled in the art that various modifications, It will be readily appreciated by those skilled in the art that modifications and variations can be applied to the dual drive device according to the claims, all of which are within the scope of the appended claims.

100, 200: first and second movable parts 110, 210: first and second fixed cylinders
120: cylinder rod 130: compression cylinder
140: first movable arc contactor 150: compression chamber
160: movable primary contactor 170: nozzle
300: motion transfer device 310: support ring
320: full bar 320p, 330p: pin
330: Dual forks 330a: Axis
330s: Slot 340: Rack
350: Guide 360: Support plate
360h1, 360h2: first and second guide holes H: groove

Claims

A first movable part driven by the power transmission mechanism and linearly moving in the same direction as the power transmission mechanism;
A motion switching device driven by the first moving part to generate a linear motion in a direction opposite to the first moving part;
And a second movable part driven by the motion switching device and linearly moving in a direction opposite to the first movable part, the double movable device comprising:
Wherein the motion switching device includes a pull bar driven by the first movable part and linearly moving in the same direction as the first movable part,
A dual fork in which one end is linked to the pull bar to convert the linear movement of the pull bar into a rotary movement and a pinion is formed at the other end,
Wherein the dual fork is coupled to the pinion of the dual fork so that the rotational motion of the dual forks can be converted into a rectilinear motion in a direction opposite to the rectilinear motion of the pool bar.

The method according to claim 1,
Wherein the first movable portion includes a first movable arc contact,
The second movable portion includes a second movable arc contactor,
Characterized in that said rack is coupled to a second movable arc contactor.

3. The method of claim 2,
Further comprising a support plate coupled to the inside of the enclosure of the gas insulated switchgear,
Wherein the support plate is provided with a first guide hole through which a rack is inserted and guided.

The method of claim 3,
Wherein the dual forks are rotatably mounted on a support block coupled to the support plate,
Wherein the support block is formed with a groove to which the rack is guided.

The method of claim 3,
And a second guide hole for guiding the pull bar is formed on the support plate.