CN111199847A

CN111199847A - Circuit breaker

Info

Publication number: CN111199847A
Application number: CN201811372389.7A
Authority: CN
Inventors: 吴长兰; 其他发明人请求不公开姓名
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-11-16
Filing date: 2018-11-16
Publication date: 2020-05-26

Abstract

The invention belongs to the field of medium and high voltage switches, and particularly discloses a circuit breaker which comprises a single-stage switch, wherein the single-stage switch comprises a vacuum bulb, an insulating cylinder, an electromagnetic driver and an elastic eliminating device which are axially connected. The bullet eliminating device comprises a cylinder body, and a piston, a drainage mechanism, a flow blocking mechanism and a drainage channel which are positioned in the cylinder body. The drainage mechanism is arranged at the upper end part of the piston, a contact bar of the drainage mechanism protrudes out of the upper end surface of the piston and extends into a bar cavity, and the contact bar is suitable for impacting an end cover with the bar cavity to trigger the drainage mechanism to drain, so that the driving force for enabling the movable contact to bounce reversely generated by a damping medium in the bar cavity at the stroke end is eliminated; the flow resisting mechanism is arranged at the lower end part of the piston, the drainage channel is arranged in the piston, the drainage mechanism is communicated with the flow resisting mechanism through the drainage channel, and a damping medium in the rodless cavity can only flow into the rod cavity through the damping hole in the piston, so that the rebound eliminating device can further absorb the energy of reverse bounce of the moving contact after closing, and the closing bounce arcing of the circuit breaker is effectively avoided.

Description

Circuit breaker

Technical Field

The invention relates to a medium-high voltage switch, in particular to a breaker suitable for medium and high voltages, and belongs to the field of power equipment.

Background

The circuit breaker is used as a switch device for controlling on and off of a medium-voltage and high-voltage primary loop, and currently, higher requirements are put on the switching-on performance of the circuit breaker, such as shorter switching-on time, no arcing, and particularly switching-on arcing. The circuit breaker is internally provided with a vacuum bubble with an arc extinguishing function. During closing, the moving contact moving at a high speed of the vacuum bubble collides with the fixed contact to realize closing, but the moving contact moving at a high speed bounces after collision and bounces reversely at an instantaneous speed close to closing, so that the moving contact is far away from the fixed contact, and closing bouncing arcing is often generated between the moving contact and the fixed contact. The arcing ablation makes the moving contact and the static contact of the vacuum bubble easy to be damaged, the service life of the vacuum bubble is short, a large amount of manpower and material resources are needed to be consumed to maintain the vacuum bubble, and the application and maintenance cost is high. In addition, arcing is generated between the moving contact and the fixed contact of the vacuum bubble, so that the temperature in the vacuum bubble is quickly increased for the vacuum bubble filled with arc extinguishing gas, high temperature and high pressure are generated to cause explosion, major accidents are caused, and the safe operation of the power distribution network is influenced.

Disclosure of Invention

The invention mainly aims to provide a circuit breaker, which solves the technical problems that the circuit breaker in the prior art is easy to generate switch-on bounce and arcing and the vacuum bubbles are easy to damage.

In order to achieve the above object, the present invention provides a circuit breaker, which is composed of at least one single-pole switch a, the single-pole switch a comprises a vacuum bulb 100, an insulating cylinder 200, an electromagnetic driver 300, a movable contact rod 130 of the vacuum bulb 100 is connected with an upper shaft rod 220 shaft of the insulating cylinder 200, a lower shaft rod 230 of the insulating cylinder 200 is connected with an upper end shaft of a driver output shaft 370 of the electromagnetic driver 300; the design key points are as follows: the bullet eliminating device 400 is further included, and the bullet eliminating device 400 comprises a closed cylinder body 410, a piston mechanism 420, a drainage mechanism 430, a flow blocking mechanism 440 and a drainage channel 450; the piston mechanism 420 comprises a piston 421 and a piston rod 422 which are arranged in the cylinder 410, the lower end part of the piston rod 422 penetrates through the No. 1 end cover 412 of the cylinder 410 and is fixed with the piston 421 in a sealing way, the upper end part of the piston rod 422 is connected with the lower end part of the output shaft 370 of the driver, and the piston 421 is matched with the cylinder 410 in a sealing way; a damping hole 423 is formed in the piston 421, and the piston 421 divides the inner space of the cylinder 410 into a rod chamber and a rod-less chamber; the exhaust mechanism 430 is arranged inside the piston 421, the exhaust mechanism 430 includes an exhaust valve core 433, a contact rod 4332 of the exhaust valve core 433 protrudes from an upper end surface of the piston 421 and extends into the rod cavity, the flow blocking mechanism 440 is arranged inside the piston 421 and is located on a lower end surface side of the piston 421, the exhaust passage 450 is arranged inside the piston 421, one end of the exhaust passage 450 is communicated with the exhaust mechanism 430, and the other end of the exhaust passage 450 is communicated with the flow blocking mechanism 440, and the exhaust valve core 433 is suitable for impacting the 1 st end cap 412 to trigger the exhaust mechanism 430 and the flow blocking mechanism 440 to exhaust, so that the damping medium in the rod cavity is exhausted into the rodless cavity through the exhaust mechanism 430, the exhaust passage 450 and the flow blocking mechanism 440, and the flow blocking mechanism 440 is suitable for preventing the damping medium from being exhausted from the rodless cavity to the rod cavity through the exhaust mechanism 430.

In the application and implementation process, the invention also has the following optional technical scheme.

Optionally, the drainage mechanism 430 includes a drainage chamber 431, a drainage valve seat 432, a drainage valve core 433, a 1 st return spring 434, and a head cover 435; the discharge chamber 431 is a chamber provided in the piston 421 and having an open lower end, and extends in the axial direction of the piston 421; an upper end part of the drainage cavity 431 is internally provided with a drainage valve seat 432, and a contact rod hole is arranged in the middle of the drainage valve seat 432; the drain spool 433 includes a spool portion 4331 and a bank rod 4332; the drain valve core 433 and the 1 st return spring 434 are sequentially assembled in the drain cavity 431, a contact rod 4332 penetrates through a contact rod hole, protrudes out of the upper end surface of the piston 421 and extends into the rod cavity, the end head cover 435 and the lower end opening of the drain cavity 431 are fixed in a sealing mode, the 1 st return spring 434 is in a compressed state, and the valve core part 4331 is in sealing fit with the drain valve seat 432; the lower end of the discharge chamber 431 communicates with one end of the discharge passage 450.

Optionally, the choke mechanism 440 includes a choke chamber 441, a choke valve seat 442, a choke valve core 443, a 2 nd return spring 444, and an end pressure plate 445; the flow blocking chamber 441 is a chamber that is provided in the piston 421 and has an opening at a lower end portion, and extends in the axial direction of the piston 421; the choke valve seat 442 is disposed at an upper end portion of the choke chamber 441, and a choke blind hole 446 which is communicated with the choke chamber 441 and extends upward and does not penetrate through an upper end surface of the piston 421 is disposed in the middle of the choke valve seat 442; the choke valve core 443 and the 2 nd return spring 444 are sequentially assembled in the choke cavity 441, the end pressure plate 445 and the lower end opening of the choke cavity 441 are fixed, the 2 nd return spring 444 is in a compressed state, and the choke valve core 443 is in sealing fit with the choke valve seat 442; the blind flow blocking hole 446 communicates with the other end of the exhaust passage 450.

Alternatively, the exhaust passage 450 includes a 1 st exhaust passage 451, a 2 nd exhaust passage 452, and a 3 rd exhaust passage 453, which are disposed in the piston 421 and communicate in this order; the 1 st discharge passage 451 is located on the lower end surface side of the piston 421, and communicates with the lower end portion of the discharge chamber 431; the 3 rd exhaust passage 453 is located on the upper end surface side of the piston 421, and communicates with the blind flow blocking hole 446.

Alternatively, the 1 st discharge passage 451 is a circular arc-shaped hole extending in the piston circumferential direction, the 3 rd discharge passage 453 is a linear hole extending in the piston axial direction, and the 2 nd discharge passage 452 is a circular arc-shaped hole extending in the piston circumferential direction; one end of the 1 st exhaust passage 451 communicates with the lower end of the exhaust chamber 431, and the other end communicates with the lower end of the 3 rd exhaust passage 453; the upper end of the 3 rd exhaust channel 453 is connected to one end of the 2 nd exhaust channel 452, and the other end of the 2 nd exhaust channel 452 is connected to the blind flow-blocking hole 446.

Optionally, the blind flow-blocking hole 446, the flow-blocking valve seat 442 and the flow-blocking cavity 441 are coaxially matched; the discharge cavity 431, the discharge valve seat 432 and the feeler lever hole are coaxially matched.

Optionally, the cylinder 410 includes a cylinder 411, a 1 st end cap 412, and a 2 nd end cap 413; the cylinder 411 is cylindrical and has two open ends, the 1 st end cap 412 is sealingly engaged with and fixed to the upper end of the cylinder 411, and the 2 nd end cap 413 is sealingly engaged with and fixed to the lower end of the cylinder 411.

Optionally, the insulation cartridge 200 comprises an insulator 210, an upper shaft 220, and a lower shaft 230; the insulator 210 is in a column shape, and a plurality of sheds suitable for increasing the insulation creepage distance are arranged on the side surface of the insulator; the upper shaft 220 is fixed to the upper end of the insulator 210, and the lower shaft 230 is fixed to the lower end of the insulator 210.

Alternatively, the electromagnetic actuator 300 comprises an actuator cylinder 310 in a cylindrical shape, an actuator upper end cover 320, an actuator lower end cover 330, an iron core 360 and an actuator output shaft 370, wherein a 1 st caulking groove 311 and a 2 nd caulking groove 312 which are circumferentially surrounded are arranged on the inner side wall of the actuator cylinder 310, the 1 st caulking groove 311 is arranged at the upper end part of the cylinder 310, and the 2 nd caulking groove 312 is arranged at the lower end part of the cylinder 310; the 1 st coil 340 is assembled in the 1 st embedded groove 311, and the 2 nd coil 350 is assembled in the 2 nd embedded groove 312; the iron core 360 is arranged in the cylinder body 310, sleeved outside the driver output shaft 370 and fixed, the driver upper end cover 320 is fixed with the upper end of the cylinder body 310, the driver lower end cover 330 is fixed with the lower end of the cylinder body 310, the upper end part of the driver output shaft 370 penetrates through a middle through hole of the driver upper end cover 320 and extends out, and the lower end part penetrates through a middle through hole of the driver lower end cover 330 and extends out.

Optionally, the number of single-pole switches is 1, 2, 3 or more.

The circuit breaker of the invention is composed of at least one single-pole switch, and the single-pole switch comprises a vacuum bulb, an insulating cylinder, an electromagnetic driver and a bullet eliminating device. The movable contact rod of the vacuum bubble is connected with the upper shaft rod of the insulating cylinder, and the lower shaft rod of the insulating cylinder is connected with the upper end part shaft of the driver output shaft of the electromagnetic driver. The bullet eliminating device comprises a closed cylinder body, a piston mechanism, a drainage mechanism, a flow blocking mechanism and a drainage channel. The piston mechanism comprises a piston and a piston rod which are arranged in a cylinder body. The lower end part of the piston rod penetrates through the No. 1 end cover of the cylinder body and is fixed with the piston in a sealing mode, and the upper end part of the piston rod is connected with the lower end part of the output shaft of the driver through a shaft. The piston is in sealing fit with the cylinder body. The piston is provided with a damping hole, and the piston divides the inner space of the cylinder body into a rod cavity and a rodless cavity. The drainage mechanism is arranged in the piston and comprises a drainage valve core, a contact rod of the drainage valve core protrudes out of the upper end face of the piston and extends into the rod cavity, the flow blocking mechanism is arranged in the piston and is positioned on the lower end face side of the piston, the drainage channel is arranged in the piston, one end of the drainage channel is communicated with the drainage mechanism, and the other end of the drainage channel is communicated with the flow blocking mechanism. The drainage valve core of the drainage mechanism impacts the No. 1 end cover to sequentially trigger the drainage mechanism and the flow-blocking mechanism to drain, damping media in the rod cavity are discharged into the rodless cavity through the drainage mechanism, the drainage channel and the flow-blocking mechanism, the damping media with high energy stored in the rod cavity are discharged into the rodless cavity through the drainage mechanism, and the driving force generated by the damping media at the stroke end and used for promoting the reverse bounce of the moving contact is eliminated so as to inhibit the closing bounce of the moving contact. After the circuit breaker is switched on, the bouncing movable contact drives the piston to move in the reverse direction, the piston moves in the reverse direction from the stroke end point, because the contact bar of the drainage valve core protrudes out of the upper end face of the piston, the drainage mechanism cannot be immediately reset to block circulation, under the action of the 2 nd reset spring, the flow blocking mechanism is immediately reset to block circulation, damping media in the rodless cavity are prevented from draining to the rod cavity through the drainage mechanism, the damping media in the rodless cavity can only flow into the rod cavity through the damping hole in the piston to generate damping force, the energy of the reverse bounce of the movable contact after switching on is absorbed, and the reverse bounce of the contact is further inhibited, so that the arc burning of the switching on bounce of the movable contact of the circuit breaker is avoided, and the switching-on.

When the breaker is switched on, the electromagnetic driver drives the piston of the bounce eliminating device to move towards the direction of the rod cavity, the damping medium in the rod cavity is compressed by doing work and flows into the rodless cavity through the damping hole on the piston to generate damping force, so that part of energy of a moving contact of the breaker before switching on is absorbed, and the instantaneous speed of switching on is reduced, thereby inhibiting the moving contact of the breaker from generating switching-on bounce; when a piston of the bullet eliminating device is at the tail end of a stroke, a contact rod of a drainage valve core impacts an end cover with a rod cavity, a drainage mechanism is triggered to drain, a high-energy damping medium stored in the rod cavity flows into a drainage channel, the damping medium flowing into the drainage channel extrudes a flow blocking valve core of a flow blocking mechanism, the flow blocking valve core is far away from a flow blocking valve seat, the flow blocking mechanism is triggered to drain, namely the drainage mechanism and the flow blocking mechanism are sequentially triggered to drain, the high-energy damping medium stored in the rod cavity at the tail end of the stroke flows to a rodless cavity through the drainage mechanism, the drainage channel and the flow blocking mechanism, the driving force generated by the damping medium at the tail end of the stroke of the bullet eliminating device and used for promoting the reverse bounce of a moving contact is eliminated, and the reverse bounce generated when the moving contact is switched; after the circuit breaker is switched on, the moving contact generates switching-on bounce to drive a piston of the bounce eliminating device to reversely move from a stroke end point, because a contact bar 4332 of the drainage mechanism 430 protrudes out of the upper end surface of the piston 421, the drainage mechanism cannot be immediately reset to block circulation under the action of a 1 st reset spring, and a flow blocking mechanism is immediately reset to block circulation under the action of a 2 nd reset spring, so that damping media in a rodless cavity can only flow into a rod cavity through a damping hole in the piston to generate damping force, the energy of the reverse bounce of the moving contact after the circuit breaker is switched on is absorbed, and the reverse bounce of the moving contact is further inhibited, so that the switching-on bounce arcing between the moving contact and a static contact of the circuit breaker is avoided, and the switching-on performance and the.

Compared with the prior art, the invention has the beneficial effects that: the breaker is internally provided with the shell eliminating device, when the breaker is switched on, the shell eliminating device absorbs partial energy of a moving contact of the breaker before switching on to reduce the instantaneous speed of switching on, eliminates the driving force of the shell eliminating device generated at the tail end of a stroke and promoting the reverse bounce of the moving contact, absorbs the energy of the reverse bounce of the moving contact after switching on, and inhibits the moving contact of the breaker from reversely bouncing, so that the switching-on bounce arcing between the moving contact and the fixed contact is avoided, the service life of the breaker is prolonged, the explosion caused by the arcing of the breaker is avoided, and the switching-on performance and the safety of the breaker are improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic diagram of a circuit breaker according to an embodiment.

Fig. 2 is a schematic diagram of an electromagnetic drive.

Fig. 3 is a schematic view of the missile eliminating device.

Fig. 4 is an enlarged view of the AA region in fig. 3.

Fig. 5 is a bottom view of the piston of fig. 3.

Fig. 6 is a schematic sectional view taken along the direction B-B in fig. 5.

Fig. 7 is an exploded view of the exhaust and flow blocking mechanisms.

Wherein, 100-vacuum bulb, 110-vacuum chamber, 120-moving contact, 130-moving contact rod, 140-static contact, 150-static contact rod, 200-insulating cylinder, 210-insulator, 220-upper shaft rod, 230-lower shaft rod, 300-electromagnetic driver, 310-driver cylinder body, 311-1 st caulking groove, 312-2 nd caulking groove, 313-permanent magnet, 320-driver upper end cover, 330-driver lower end cover, 340-1 st coil, 350-2 nd coil, 360-iron core, 370-driver output shaft, 400-bullet-eliminating device, 410-cylinder body, 411-cylinder barrel, 412-1 st end cover, 413-2 nd end cover, 414-axial pressure plate, 415-1 st sealing ring, 416-2 nd sealing ring, 420-piston mechanism, 421-piston, 422-piston rod, 423-damping hole, 424-3 rd sealing ring, 425-4 th sealing ring, 430-drainage mechanism, 431-drainage cavity, 432-drainage valve seat, 433-drainage valve core, 4331-valve core part, 4332-contact rod, 434-1 st return spring, 435-end, 440-flow blocking mechanism, 441-flow blocking cavity, 442-flow blocking valve seat, 443-flow blocking valve core, 444-2 nd return spring, 445-end pressure plate, 446-flow blocking blind hole, 450-drainage channel, 451-1 st drainage channel, 452-2 nd drainage channel, 453-3 rd channel.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. The directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the movement, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indication is changed accordingly.

As described in the background art, when a circuit breaker in the prior art is operated to be switched on, switching-on bounce often occurs, so that switching-on bounce arcing is generated between a moving contact and a fixed contact of a vacuum bubble of the circuit breaker, arcing ablation causes the moving contact and the fixed contact of the vacuum bubble to be easily damaged, the service life of the vacuum bubble is shortened, a large amount of manpower and material resources are consumed to maintain the circuit breaker in a daily use process, and the application and maintenance cost is high. In addition, arcing is generated between the moving contact and the fixed contact of the vacuum bubble, the temperature in the vacuum bubble is rapidly increased for the vacuum bubble filled with arc extinguishing gas, the vacuum bubble is exploded due to high temperature and high pressure, major accidents are caused, and the safe operation of a power grid is influenced.

The inventor further researches and discovers that the main reason that the built-in vacuum bulb of the circuit breaker generates switch-on bounce and arcing is that when the circuit breaker is switched on, the speed of a moving contact of the vacuum bulb is very high, the energy is very large, the momentum theorem shows that reverse bounce is generated when the moving contact collides with a fixed contact, the reverse bounce speed is high, the bounce stroke is large, in order to reduce or even avoid switch-on bounce generated by the moving contact of the circuit breaker, partial energy consumption of the moving contact is required to be consumed during switch-on so as to reduce the energy of the instant switch-on of the circuit breaker, the energy of the switch-on bounce of the moving contact of the vacuum bulb is reduced, the energy of the reverse bounce after the moving contact is switched on is absorbed, the.

Based on the research, after the inventor is subjected to multi-aspect experimental analysis, the breaker provided with the spring eliminating device is provided, when the breaker is switched on, the spring eliminating device absorbs partial energy of a moving contact of a vacuum bulb, the instantaneous switching-on speed of the moving contact is reduced, the energy of switching-on bounce of the moving contact is reduced, the energy of reverse bounce after the moving contact is switched on is absorbed, the moving contact of the breaker is restrained from generating switching-on bounce, switching-on bounce arcing of the vacuum bulb is avoided, the service life of the vacuum bulb is prolonged, and arcing explosion of the breaker is avoided.

As an embodiment of the present invention, there is provided a circuit breaker, as shown in fig. 1, including a base frame, three single-pole switches a, a current transformer, a voltage transformer, and a controller. The single-pole switch a is arranged upright in the vertical direction. The three single-pole switches A are arranged in a straight line shape at equal intervals and are assembled and fixed with the base frame. The 1 st terminal 160 and the 2 nd terminal 170 are provided on the single pole switch a. The single pole switch a is shown in the dashed box portion of fig. 1. The single-stage switch a includes a vacuum bulb 100, an insulating cylinder 200, an electromagnetic driver 300, and a missile eliminating device 400. The vacuum bulb 100, the insulating cylinder 200, the electromagnetic driver 300 and the missile eliminating device 400 are sequentially and fixedly connected in an axial direction and are coaxially matched to be arranged along the up-down direction, as shown in fig. 1, namely, vertically arranged. One end of the 1 st contact pin 160 is electrically connected to the stationary contact bar 150 of the vacuum bulb 100, and one end of the 2 nd contact pin 170 is electrically connected to the movable contact bar 130 of the vacuum bulb 100. The vacuum bulb 100 and the insulating cylinder 200 are arranged in the insulating column made of insulating materials so as to realize electric insulation and isolation and improve safety. The other end of the 1 st post 160 penetrates the sidewall of the insulating post to be extended to the outside, and the other end of the 2 nd post 170 penetrates the sidewall of the insulating post to be extended to the outside. The 1 st terminal 160, the vacuum bulb 100, the 2 nd terminal 170, the insulating cylinder 200, and the insulating cylinder are disposed at an upper end portion of the base frame. The electromagnetic driver 300 and the bullet eliminating device 400 are arranged at the lower end part of the base frame. The insulating material is epoxy resin, and can be replaced by nylon or PT material, and preferably epoxy resin. The current transformers are used for detecting load currents of the single-pole switches A, and each single-pole switch A is provided with one current transformer. The current transformer may be fitted over the 2 nd terminal 170 and fixed to the base frame. The voltage transformer is used for detecting the voltage of the single-pole switch A. The voltage transformer is electrically connected to the 2 nd terminal 170 of each single pole switch a, respectively, for detecting the voltage of each single pole switch. The controller is internally provided with a microprocessor, a filter circuit and a switching-on and switching-off control circuit. The switching-on and switching-off control circuit is electrically connected with the microprocessor through the filter circuit. The switching control circuit is electrically connected to the electromagnetic driver 300, and is used for operating each single-pole switch a to perform switching-on operation and switching-off operation, respectively. The current transformer and the voltage transformer are respectively and electrically connected with the microprocessor through the filter circuit.

The moving contact rod 130 of the vacuum bulb 100 is coupled with the upper shaft rod 220 of the insulating cylinder 200, and the lower shaft rod 230 of the insulating cylinder 200 is coupled with and fixed to the upper end portion of the driver output shaft 370 of the electromagnetic driver 300, and is coaxially engaged. The missile eliminating device 400 comprises a closed cylinder body 410, a piston mechanism 420, a drainage mechanism 430, a flow blocking mechanism 440 and a drainage channel 450. The piston mechanism 420 includes a piston 421 and a piston rod 422 which are arranged in the cylinder 410, the lower end of the piston rod 422 penetrates through the through hole in the middle of the 1 st end cap 412 of the cylinder 410, extends into the cylinder 410, and is assembled and fixed with the through hole in the middle of the piston 421, and the piston rod 422 is in sealing fit with the through hole in the middle of the piston 421, which can be understood as sealing fixation. The upper end of the piston rod 422 is fixedly connected to the lower end of the driver output shaft 370 and coaxially engaged therewith. The piston 421 is in sealing engagement with the cylinder 410. The piston 421 is provided with a damping hole 423, and the piston 421 divides the internal space of the cylinder 410 into a rod chamber and a rod-less chamber. The drainage mechanism 430 is arranged in the piston 421, the drainage mechanism 430 includes a drainage valve core 433, a drainage rod 4332 of the drainage valve core 433 protrudes out of the upper end surface of the piston 421 and extends into the rod cavity, and the drainage valve core 433 is suitable for impacting the 1 st end cap 412 to trigger the drainage mechanism 430 to drain, so that the damping medium in the rod cavity is discharged into the rodless cavity through the drainage mechanism 430, and the driving force generated by the damping medium at the stroke end and used for promoting the reverse bounce of the movable contact is eliminated, so as to inhibit the reverse bounce of the movable contact during closing. The choke mechanism 440 is provided inside the piston 421 on the lower end surface side of the piston 421. The exhaust passage 450 is disposed inside the piston 421, and one end of the exhaust passage 450 communicates with the exhaust mechanism 430 and the other end communicates with the flow blocking mechanism 440. The exhaust mechanism 430, the exhaust passage 450, and the flow blocking mechanism 440 form an exhaust passage for exhausting the damping medium from the rod chamber to the rod-less chamber. The flow-blocking mechanism 440 is adapted to block the flow of damping medium from the rodless chamber to the rod chamber via the drain mechanism 430, which may be understood as a one-way valve arrangement that allows damping medium to flow only from the rod chamber to the rodless chamber. After the circuit breaker is switched on, the bouncing movable contact drives the piston to move reversely, the piston moves reversely from the stroke end, the drainage mechanism cannot be reset immediately to block circulation, but the flow blocking mechanism is reset immediately to block circulation, so that the damping medium in the rodless cavity is suitable for preventing the damping medium from flowing to the rod cavity through the drainage mechanism 430, the damping medium in the rodless cavity can only flow into the rod cavity through the damping hole on the piston to generate damping force, the energy of the reverse bounce of the movable contact after switching on is absorbed, the reverse bounce of the contact is further inhibited, and the circuit breaker is ensured not to generate switching-on bounce arcing.

When the breaker is switched on, the electromagnetic driver drives the piston of the bounce eliminating device to move towards the direction of the rod cavity, the damping medium in the rod cavity is compressed by doing work and flows into the rodless cavity through the damping hole on the piston to generate damping force, so that part of energy of a moving contact of the breaker before switching on is absorbed, and the instantaneous switching-on speed is reduced to inhibit the moving contact of the breaker from switching on and bouncing; when a piston of the bullet eliminating device is at the tail end of a stroke, a contact rod of a drainage valve core impacts an end cover with a rod cavity, a drainage mechanism is triggered to drain, a high-energy damping medium stored in the rod cavity flows into a drainage channel, the damping medium flowing into the drainage channel extrudes a flow blocking valve core of a flow blocking mechanism, the flow blocking valve core is far away from a flow blocking valve seat, the flow blocking mechanism is triggered to drain, namely the drainage mechanism and the flow blocking mechanism are sequentially triggered to drain, the high-energy damping medium stored in the rod cavity at the tail end of the stroke flows to a rodless cavity through the drainage mechanism, the drainage channel and the flow blocking mechanism, the driving force generated by the damping medium and used for promoting the reverse bouncing of a moving contact is eliminated at the tail end (namely the tail end) of the stroke, and the closing reverse bouncing of the moving contact is further; after the circuit breaker is switched on, the moving contact generates switching-on bounce to drive a piston of the bounce eliminating device to reversely move from a stroke end point, because a contact bar of the drainage mechanism protrudes out of the upper end face of the piston, the drainage mechanism cannot be immediately reset to block circulation under the action of a 1 st reset spring, but a flow blocking mechanism immediately resets to block circulation under the action of a 2 nd reset spring, damping media in a rodless cavity only can flow into a rod cavity through a damping hole in the piston to generate damping force, the energy of the reverse bounce of the moving contact after switching-on is absorbed, and the reverse bounce of the moving contact is further inhibited, so that switching-on bounce arcing between the moving contact and a fixed contact of the circuit breaker is avoided, and the switching-on performance and the safety of the circuit breaker are improved.

Compared with the prior art, the embodiment has the following beneficial technical effects: the breaker is internally provided with the shell eliminating device, when the breaker is switched on, the shell eliminating device absorbs partial energy of a moving contact of the breaker before switching on to reduce the instantaneous speed of switching on, eliminates the driving force of the shell eliminating device generated at the tail end of a stroke and promoting the reverse bounce of the moving contact, absorbs the energy of the reverse bounce of the moving contact after switching on, and inhibits the reverse bounce of the switching on of the moving contact of the breaker, so that the arc of the switching on bounce between the moving contact and the fixed contact is avoided, the service life of the breaker is prolonged, the explosion caused by the arc of the breaker is avoided, and the switching-on performance and the.

As shown in fig. 1, the vacuum bulb 100 includes a vacuum chamber 110, a movable contact 120, a movable contact rod 130, a fixed contact 140, and a fixed contact rod 150. The vacuum chambers 110 are arranged in the up-down direction. The movable contact 120 and the fixed contact 140 are disposed in the vacuum chamber 110, the movable contact 120 and the fixed contact 140 are disposed oppositely, preferably in parallel, and the movable contact 120 is located below the fixed contact 140. The vacuum chamber 110 has an upper through hole at an upper end thereof and a lower through hole at a lower end thereof. The lower end of the static contact rod 150 extends into the vacuum chamber 110 from the upper through hole at the upper end of the vacuum chamber 110, the lower end of the static contact rod 150 is fixed with the static contact 140, the static contact rod 150 is hermetically matched with the upper through hole of the vacuum chamber 110 and is fixed, namely the static contact rod 150 is hermetically fixed with the vacuum chamber 110. The upper end of the moving contact rod 130 is extended into the vacuum chamber 110 from the lower through hole of the lower end of the vacuum chamber 110, the upper end of the moving contact rod 130 is fixed with the moving contact 120, and the moving contact rod 130 is hermetically fitted with the lower through hole of the vacuum chamber 110 and is slidably assembled so that the moving contact rod 130 can move up and down relative to the vacuum chamber 110 and maintain a sealed state. If the movable contact rod 130 is sealed by a corrugated pipe, the corrugated pipe is sleeved outside the movable contact rod 130 and penetrates through the lower through hole of the vacuum cavity 110, and the lower end part of the corrugated pipe is fixed with the lower through hole at the lower end of the vacuum cavity 110 and is in sealing fit, which can be understood as sealing fixation; the upper end of the bellows is sealingly engaged and fixed with the movable contact rod 130.

As shown in fig. 1, the insulation cylinder 200 includes an insulator 210, an upper shaft 220, and a lower shaft 230. The lower end of the movable contact rod 130 is fixedly connected, preferably coaxially fitted, with the upper end of the upper shaft rod 220. The insulator 210 is cylindrical and is made of an insulating ceramic, such as alumina ceramic. The outer side of the insulator 210 is provided with a plurality of sheds circumferentially surrounding along the side to increase the insulation creepage distance and enhance the electrical insulation isolation effect. The upper shaft 220 and the lower shaft 230 may be made of steel, such as stainless steel, or may be made of an insulating ceramic, such as alumina ceramic. Alternatively, the upper shaft 220 is made of stainless steel and the lower shaft 230 is made of insulating ceramic to enhance the electrical insulation effect. The lower end of the upper shaft 220 is fixed to the upper end of the insulator 210, and the upper end of the lower shaft 230 is fixed to the lower end of the insulator 210. The upper shaft 220, insulator 210, and lower shaft 230 are coaxially mated. Under the electrical insulation and isolation action of the insulator 210, the upper shaft 220 and the lower shaft 230 are electrically insulated and isolated from each other.

As shown in fig. 2, the electromagnetic actuator 300 includes a cylindrical actuator cylinder 310, an actuator upper end cap 320, an actuator lower end cap 330, a permanent magnet 313, an iron core 360, and an actuator output shaft 370. The actuator cylinder 310 is cylindrical and has open upper and lower ends. The actuator cylinder 310 has a 1 st caulking groove 311 and a 2 nd caulking groove 312 built therein. The 1 st caulking groove 311 and the 2 nd caulking groove 312 are located inside the wall of the drive cylinder 310, respectively, circumferentially surrounding; the 1 st caulking groove 311 is provided at an upper end portion of the cylinder body 310, and the 2 nd caulking groove 312 is provided at a lower end portion of the cylinder body 310. The 1 st coil 340 is assembled in the 1 st embedded groove 311, and the 1 st coil 340 is fixed with the 1 st embedded groove 311 and is suitable for driving a breaker to close; the 2 nd coil 350 is assembled in the 2 nd embedded groove 312, and the 2 nd coil 350 is fixed with the 2 nd embedded groove 312 and is suitable for driving the opening of the breaker. The permanent magnet 313 is fixed to the inner wall of the actuator cylinder 310 at a middle region of the actuator cylinder 310, i.e., between the 1 st coil 340 and the 2 nd coil 350, arranged along the circumferential direction of the inner wall of the actuator cylinder 310. The plunger 360 is disposed within the cylinder 310, and the plunger 360 is fixed to and sleeved outside the driver output shaft 370 and located in a middle region of the driver output shaft 370. The core 360 is located within the circumferentially arranged permanent magnets 313, coaxially mated. The upper end cover 320 of the driver is fixed with the upper end of the cylinder body 310, and the upper end part of the output shaft 370 of the driver penetrates through the through hole in the middle of the upper end cover 320 of the driver and extends out; the lower end cover 330 of the driver is fixed to the lower end of the cylinder 310, and the lower end of the output shaft 370 of the driver extends through the through hole in the middle of the lower end cover 330 of the driver. The upper end of the driver output shaft 370 is fixed, further coaxially engaged, with the lower end of the lower shaft 230.

As shown in fig. 1 and 3, the cylinder 410 includes a cylindrical cylinder 411, a 1 st end cap 412, and a 2 nd end cap 413. The upper and lower both ends of cylinder 411 are open, and 1 st end cover 412 covers the upper end opening at cylinder 411 and realizes sealed fixed through integrated into one piece mode. The 2 nd end cap 413 is fixed to cover the lower end opening of the cylinder 411, and the 2 nd end cap 413 and the cylinder 411 are sealed by the 1 st gasket 415. The piston mechanism 420 includes a piston 421 and a piston rod 422. The piston 421 is arranged in the cylinder 410, one end of the piston rod 422 penetrates through the through hole in the middle of the 1 st end cap 412, extends into the cylinder 410, and is fixed with the piston 421, and the piston rod 422 and the through hole in the middle of the piston 421 are sealed by a 3 rd sealing ring 424; the piston rod 422 and the through hole in the middle of the 1 st end cover 412 are sealed through the 2 nd sealing ring 416, and the shaft pressure plate 414 is sleeved on the piston rod 422 and fixed with the 1 st end cover 412 and used for extruding the 2 nd sealing ring 416 to ensure a good sealing effect. The side surface of the piston 421 and the inner wall surface of the cylinder 411 are sealed by a 4 th sealing ring 425. The piston 421 divides the inner space of the cylinder 410 into a rod chamber located above and a rod-less chamber located below, as shown in fig. 3. The piston 421 is provided with a damping hole 423 adapted to allow a damping medium to flow between the rod chamber and the rodless chamber to release the energy stored by the compressed damping medium, so as to generate a damping force and absorb the energy of the movable contact of the circuit breaker. The area of the damping hole 423 is 0.6-1.3%, preferably 0.75% of the area of the piston 421, and the effect of suppressing the switch-on bounce of the movable contact is good. The cylinder 410 is filled with a damping medium, preferably nitrogen, or other inert gases such as helium and neon, so as to prevent oxidation of the sealing element and prolong the service life. The cylinder 410 is filled with high pressure nitrogen gas having a pressure greater than one standard atmospheric pressure, and the pressure of the high pressure nitrogen gas is preferably 2 standard atmospheric pressures. The 2 nd end cap 413 is provided with a through hole extending in the axial direction thereof, and a check valve that is communicated from the outside to the inside and is blocked from the inside to the outside is fitted in the through hole. The design of the check valve facilitates filling of the damping medium into the cylinder 410 while preventing leakage of the damping medium. It is convenient to inject the damping medium into the cylinder 410. It should be noted that the damping medium may also be damping oil, and when the damping oil is selected as the damping medium, the area of the damping hole 423 is larger, and is 2-8%, preferably 4.8%, of the area of the piston.

The exhaust mechanism 430, as shown in fig. 3-7, includes a discharge chamber 431, a discharge valve seat 432, a discharge valve core 433, a 1 st return spring 434, and a head cover 435. The tip cap 435 is disc-shaped. The discharge chamber 431 is provided in the piston 421, and as shown in fig. 4, is a chamber provided in the piston 421, which is open at the lower end portion, extends in the axial direction of the piston 421, and may be a chamber having a circular cross section. The discharge valve seat 432 is provided at the inner end of the discharge chamber 13, i.e., the blind end on the rod chamber side, such as the upper end of the discharge chamber 431 shown in fig. 7, on the rod chamber side. The center of the exhaust valve seat 432 is provided with a through hole communicating with the rod chamber for communication between the exhaust chamber 431 and the rod chamber, which is called a contact rod hole. The cross-sectional area of the lever bore is smaller than the cross-sectional area of the drainage chamber 431. Alternatively, the discharge chamber 431 and the discharge valve seat 432 are coaxially matched with the ram bore to facilitate machining, and are cylindrical bores. The drain spool 433 includes a spool portion 4331 and a drain rod 4332, and the spool portion 4331 is in sealing engagement with the drain valve seat 432. Alternatively, the spool portion 4331 and the trip rod 4332 are coaxially mated to fit the drain chamber 431, the drain valve seat 432, and the trip rod bore. The drain spool 433 is installed in the drain chamber 431, and the contact rod 4332 of the drain spool 433 penetrates through a contact rod hole of the drain valve seat 432, protrudes out of the upper end surface of the piston 421, and extends into a rod chamber of the cylinder 411, so that the contact rod 4332 is suitable for impacting the 1 st end cap 412, so that the drain spool 433 is far away from the drain valve seat 432, and the drain mechanism 430 is triggered to drain, that is, a state in which the damping medium can flow. The height of the row bar 4332 protruding from the upper end face of the piston 421 is labeled H0. The 1 st return spring 434 is installed in the discharge chamber 431, and the end cap 435 and the lower end of the discharge chamber 431 are fixed in an open and sealing fit, i.e., are fixed in a sealing manner, and are located at the lower end of the piston 421. Namely, the above-mentioned drain valve core 433, the 1 st return spring 434, and the head cover 435 are sequentially assembled with the drain chamber 431, the drain valve seat 432, the drain valve core 433, the 1 st return spring, and the head cover 435 are sequentially attached to each other, the 1 st return spring is in a compressed state, and the drain valve seat 432 is in sealing engagement with the drain valve core 433, that is, the drain mechanism 430 is in a flow blocking state. When the circuit breaker is switched on, the piston 421 of the bounce eliminating device moves towards the direction of the rod cavity, at the stroke end, the contact-discharge rod 4332 impacts the end cap 412 1, the discharge valve core 433 moves towards the direction far away from the discharge valve seat 432, namely, the discharge mechanism 430 is triggered to discharge current, damping medium flows into the discharge channel 450 from the rod cavity through the discharge mechanism 430, the damping medium flowing into the discharge channel stores high energy, the flow blocking mechanism 440 is triggered to discharge current, the damping medium flows towards the rodless cavity, the energy stored in the damping medium in the rod cavity at the stroke end is released, the driving force for driving the piston to move reversely from the stroke end is eliminated, the moving contact of the circuit breaker is favorably inhibited from generating switching-on bounce, and arc burning of the circuit breaker. When the discharge mechanism 430 is activated to discharge, in order to facilitate the damping medium to flow, the outer side surface of the discharge valve core 433 is provided with a discharge groove extending in the axial direction thereof.

When the piston 421 moves in the reverse direction (e.g. bouncing after closing) from the end of its stroke (i.e. the end point when closing), under the action of the 1 st return spring 434, because the contacting rod 4332 of the drainage mechanism 430 protrudes from the upper end surface of the piston 421, during the contact action between the top end of the contacting rod 4332 and the 1 st end cap 412, the drainage valve core 433 cannot be immediately reset, and the drainage mechanism 430 is still in the drainage triggered state, and the damping medium in the rodless cavity mainly flows into the rod cavity through the drainage mechanism 43, and cannot generate a damping force, but cannot absorb the energy of the reverse bounce of the moving contact, cannot suppress the reverse bounce of the moving contact after closing, and cannot avoid the occurrence of closing bounce arcing.

As shown in fig. 4 and 7, the choke mechanism 440 includes a choke chamber 441, a choke valve seat 442, a choke valve core 443, a 2 nd return spring 444, an end pressure plate 445, and a choke blind hole 446. The middle of the end pressure plate 445 is provided with a through hole suitable for the circulation of the damping medium. The flow blocking chamber 441 is provided in the piston 421, is located on the lower end surface side of the piston 421, extends downward in the axial direction of the piston 421, and is a chamber whose lower end portion is open. The choke valve seat 442 is disposed in the choke chamber 441 at an upper end portion of the choke chamber 441, a choke blind hole 446 is disposed at an upper end portion of the choke valve seat 442 at a middle portion thereof, and the choke blind hole 446 is a blind hole that extends upward from the choke valve seat 442 and does not penetrate through an upper end surface of the piston 421. The choke blind hole 446 communicates with the choke chamber 441. The flow blocking valve core 443 is in sealing fit with the flow blocking valve seat 442, and for convenience of machining, the flow blocking cavity 441, the flow blocking valve seat 442 and the flow blocking blind hole 446 are coaxially matched, and the flow blocking cavity 441 and the flow blocking blind hole 446 adopt structures with circular cross sections, so that machining is facilitated. The diameter of the flow blocking chamber 441 is larger than that of the blind flow blocking hole 446, so that the flow blocking valve seat 442 is provided at the upper end portion of the flow blocking chamber 441. The choke spool 443 sealingly engages the choke valve seat 442. The choke valve core 443 and the 2 nd return spring 444 are sequentially assembled in the choke chamber 441, and the end pressure plate 445 is fixed to an opening at the lower end of the choke chamber 441; the 2 nd reset spring 444 is in a compressed state, the choke valve core 443 is in sealing fit with the choke valve seat 442, the choke mechanism 440 is in a blocked circulation state, and is suitable for preventing damping medium in the rodless cavity from draining to the rod cavity through the drainage mechanism 430 and the drainage channel 450, the choke mechanism 440 essentially corresponds to a one-way valve device, the damping medium can only drain to the rod cavity through the damping hole 423 on the piston, and generates a damping force, so that the bounce eliminating device absorbs energy of reverse bounce after the moving contact of the circuit breaker is switched on, and further inhibits the switching-on reverse bounce of the moving contact of the circuit breaker. When the choke means 440 is activated to discharge, in order to facilitate the flow of damping medium, the outer lateral surface of the choke spool 443 is provided with discharge grooves extending in the axial direction thereof, and the discharge grooves may also be provided on the inner wall of the choke chamber 441.

As shown in fig. 5 and 6, the exhaust passage 450 is disposed inside the piston 421, and the exhaust passage 450 includes a 1 st exhaust passage 451, a 2 nd exhaust passage 452, and a 3 rd exhaust passage 453, which are disposed inside the piston 421 and are sequentially communicated with each other. The 1 st discharge passage 451 is located on the lower end surface side of the piston 421, is an arc-shaped hole extending in the circumferential direction of the piston 421, and is preferably an arc-shaped hole located inside the piston 421, as shown in fig. 5 and 6; one end of the 1 st discharge passage 451 communicates with the lower end of the discharge chamber 431, as shown in fig. 6. The 2 nd discharge passage 452 is provided on the upper end surface side of the piston 421, and is an arc-shaped hole extending in the circumferential direction of the piston 421, and a hole located inside the piston 421 is preferably an arc-shaped hole as shown in fig. 5; one end of the 2 nd discharge passage 452 communicates with the upper end of the blind flow blocking hole 446, as shown in fig. 6. The 3 rd exhaust passage 453 is provided inside the piston 421 to extend in the axial direction of the piston 421, and as shown in fig. 6, a lower end portion of the 3 rd exhaust passage 453 communicates with the other end portion of the 1 st exhaust passage 451, and an upper end portion of the 3 rd exhaust passage 453 communicates with the other end portion of the 2 nd exhaust passage 452. Therefore, the discharge cavity 431, the 1 st discharge passage 451, the 3 rd discharge passage 453, the 2 nd discharge passage 452, the blind flow blocking hole 446 and the flow blocking cavity 441 are sequentially communicated, so that a flow path is formed for allowing the damping medium in the rod cavity to flow into the rodless cavity through the discharge cavity 431, the discharge passage 450 and the flow blocking cavity 441, and the damping medium can only flow out from the rod cavity to the rodless cavity through the discharge mechanism 430 and the flow blocking mechanism 440.

When the breaker is switched on, the electromagnetic driver 300 drives the piston of the bounce eliminating device to move towards the direction of the rod cavity, the damping medium in the rod cavity is compressed, and the damping medium in the rod cavity flows into the rodless cavity through the damping hole in the piston to generate damping force, so that part of energy of a moving contact of the breaker before switching on is absorbed, and the instantaneous switching-on speed of the moving contact is reduced, so that the switching-on bounce of the moving contact of the breaker is inhibited; when the piston of the bounce eliminating device is at the end of the stroke, the contact rod 4332 of the drainage mechanism 430 impacts the 1 st end cover 412, the drainage valve core 433 moves in a direction away from the drainage valve seat 432, the drainage mechanism 430 is triggered to drain, the damping medium in the rod cavity flows into the drainage channel 450, the damping medium flowing into the drainage channel 450 presses the flow blocking valve core 443 of the flow blocking mechanism 440, the flow blocking valve core 443 moves in a direction away from the flow blocking valve seat 442, the flow blocking mechanism 440 is triggered to drain, that is, after the contact rod 4332 impacts the 1 st end cover 412, the drainage mechanism 430 and the flow blocking mechanism 440 are sequentially triggered to drain, the damping medium in the rod cavity flows into the rodless cavity through the drainage mechanism 430, the drainage channel 450 and the flow blocking mechanism 440, the energy stored at the end of the stroke of the bounce eliminating device 400 is released, the driving force of the movable contact terminal generated by the damping medium at the end of the stroke of the bounce eliminating device for driving the circuit breaker to be closed and bounced is eliminated, further inhibiting the switch-on bounce of a moving contact of the breaker; after the circuit breaker is switched on, the moving contact which bounces reversely drives the piston to move reversely, the piston moves reversely from the stroke end, under the action of the 1 st return spring 434, but because the contact bar 4332 of the drainage mechanism 430 protrudes out of the upper end surface of the piston 421, during the contact action of the top end of the contact bar 4332 and the 1 st end cap 412, the drainage valve core 433 cannot be reset immediately, the drainage mechanism 430 is still in a triggered drainage state, that is, the drainage mechanism 430 cannot be reset immediately to block the circulation, but under the action of the restoring force of the 2 nd return spring, the flow blocking valve core 443 of the flow blocking mechanism 440 keeps sealed with the flow blocking valve seat 442, that is, the flow blocking mechanism 440 is reset immediately to block the circulation, the damping medium in the rodless cavity is prevented from flowing to the rod cavity through the drainage mechanism 430, the damping medium in the rodless cavity can only flow into the rod cavity through the damping hole on the piston 421, a damping force is generated, and the energy of the moving contact which bounces, and further, the reverse bounce of the closing of the moving contact is inhibited. The three technical means are adopted to inhibit the moving contact of the circuit breaker from generating reverse bounce, so that the moving contact of the circuit breaker is prevented from generating switching-on bounce arcing, explosion caused by the arcing of the circuit breaker is avoided, and the switching-on performance and the safety of the circuit breaker are improved.

Compared with the prior art, the invention has the following beneficial technical effects:

the breaker is internally provided with the shell eliminating device, when the breaker is switched on, the shell eliminating device absorbs partial energy of a moving contact of the breaker before switching on to reduce the instantaneous speed of switching on, eliminates the driving force of the shell eliminating device generated at the tail end of a stroke and promoting the reverse bounce of the moving contact, absorbs the energy of the reverse bounce of the moving contact after switching on, and inhibits the moving contact of the breaker from reversely bouncing, so that the switching-on bounce arcing between the moving contact and the fixed contact is avoided, the service life of the breaker is prolonged, the explosion caused by the arcing of the breaker is avoided, and the switching-on performance and the safety of the breaker are improved.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the foregoing description only for the purpose of illustrating the principles of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims, specification, and equivalents thereof.

Claims

1. A circuit breaker is composed of at least one single-pole switch (A), the single-pole switch (A) comprises a vacuum bubble (100), an insulating cylinder (200) and an electromagnetic driver (300), a movable contact rod (130) of the vacuum bubble (100) is connected with an upper shaft rod (220) of the insulating cylinder (200) in a shaft mode, a lower shaft rod (230) of the insulating cylinder (200) is connected with an upper end portion shaft of a driver output shaft (370) of the electromagnetic driver (300) in a shaft mode; the method is characterized in that: the bullet eliminating device (400) comprises a closed cylinder body (410), a piston mechanism (420), a drainage mechanism (430), a flow blocking mechanism (440) and a drainage channel (450); the piston mechanism (420) comprises a piston (421) and a piston rod (422) which are arranged in the cylinder body (410), the lower end part of the piston rod (422) penetrates through a No. 1 end cover (412) of the cylinder body (410) and is fixed with the piston (421) in a sealing way, the upper end part of the piston rod (422) is connected with the lower end part shaft of the driver output shaft (370), and the piston (421) is matched with the cylinder body (410) in a sealing way; the piston (421) is provided with a damping hole (423), and the piston (421) divides the inner space of the cylinder (410) into a rod cavity and a rodless cavity; the drainage mechanism (430) is arranged inside the piston (421), the drainage mechanism (430) comprises a drainage valve core (433), a contact and drainage rod (4332) of the drainage valve core (433) protrudes out of the upper end surface of the piston (421) and extends into a rod cavity, the flow blocking mechanism (440) is arranged inside the piston (421) and is positioned on the lower end surface side of the piston (421), the drainage channel (450) is arranged inside the piston (421), one end of the drainage channel (450) is communicated with the drainage mechanism (430), the other end of the drainage channel is communicated with the flow blocking mechanism (440), and the drainage mechanism (430) and the flow blocking mechanism (440) are triggered by the fact that the drainage valve core (433) impacts a 1 st end cover (412) to trigger the drainage mechanism (430) and the flow blocking mechanism (440) to drain damping medium in the rod cavity through the drainage mechanism (430), the exhaust passage (450) and the flow blocking mechanism (440) are discharged into the rod-less chamber, and the flow blocking mechanism (440) is adapted to prevent the damping medium from being discharged from the rod-less chamber to the rod-less chamber through the exhaust mechanism (430).

2. The circuit breaker of claim 1, wherein: the drainage mechanism (430) comprises a drainage cavity (431), a drainage valve seat (432), a drainage valve core (433), a 1 st return spring (434) and a head cover (435); the discharge cavity (431) is a cavity which is arranged in the piston (421) and has an opening at the lower end part, and extends along the axial direction of the piston (421); an upper end part of the drainage cavity (431) is internally provided with a drainage valve seat (432), and the middle part of the drainage valve seat (432) is provided with a contact rod hole; the drain valve core (433) comprises a valve core part (4331) and a contact bar (4332); the drainage valve core (433) and the 1 st return spring (434) are sequentially assembled in the drainage cavity (431), a touch rod (4332) penetrates through a touch rod hole to protrude out of the upper end face of the piston (421) and extends into the rod cavity, a head cover (435) and a lower end opening of the drainage cavity (431) are fixed in a sealing mode, the 1 st return spring (434) is in a compressed state, and the valve core part (4331) is matched with the drainage valve seat (432) in a sealing mode; the lower end of the drainage chamber (431) communicates with one end of the drainage channel (450).

3. The circuit breaker of claim 2, wherein: the flow blocking mechanism (440) comprises a flow blocking cavity (441), a flow blocking valve seat (442), a flow blocking valve core (443), a 2 nd return spring (444) and an end pressure plate (445); the flow blocking cavity (441) is a cavity which is arranged in the piston (421) and has an opening at the lower end part, and extends along the axial direction of the piston (421); the flow blocking valve seat (442) is arranged at the upper end part of the flow blocking cavity (441), and the middle part of the flow blocking valve seat (442) is provided with a flow blocking blind hole (446) which is communicated with the flow blocking cavity (441), extends upwards and does not penetrate through the upper end surface of the piston (421); the flow blocking valve core (443) and the 2 nd return spring (444) are sequentially assembled in the flow blocking cavity (441), the end pressure plate (445) and the lower end opening of the flow blocking cavity (441) are fixed, the 2 nd return spring (444) is in a compressed state, and the flow blocking valve core (443) is in sealing fit with the flow blocking valve seat (442); the blind flow-blocking hole (446) communicates with the other end of the discharge channel (450).

4. The circuit breaker of claim 3, wherein: the exhaust passage (450) comprises a 1 st exhaust passage (451), a 2 nd exhaust passage (452) and a 3 rd exhaust passage (453) which are arranged in the piston (421) and communicated in sequence; the 1 st drainage channel (451) is positioned on the lower end face side of the piston (421) and communicated with the lower end part of the drainage cavity (431); the 3 rd discharge passage (453) is located on the upper end face side of the piston (421) and is communicated with the blind flow blocking hole (446).

5. The circuit breaker of claim 4, wherein: the 1 st discharge channel (451) is an arc-shaped hole extending along the circumferential direction of the piston, the 3 rd discharge channel (453) is a linear hole extending along the axial direction of the piston, and the 2 nd discharge channel (452) is an arc-shaped hole extending along the circumferential direction of the piston; one end of the 1 st drainage channel (451) is communicated with the lower end of the drainage cavity (431), and the other end is communicated with the lower end of the 3 rd drainage channel (453); the upper end of the 3 rd drainage channel (453) is communicated with one end of the 2 nd drainage channel (452), and the other end of the 2 nd drainage channel (452) is communicated with the blind flow blocking hole (446).

6. The circuit breaker of claim 5, wherein: the flow blocking blind hole (446), the flow blocking valve seat (442) and the flow blocking cavity (441) are coaxially matched; the discharge cavity (431), the discharge valve seat (432) and the feeler lever hole are coaxially matched.

7. The circuit breaker of claim 6, wherein: the cylinder body (410) comprises a cylinder barrel (411), a 1 st end cover (412) and a 2 nd end cover (413); the cylinder (411) is cylindrical and has two open ends, the 1 st end cover (412) is matched and fixed with the upper end of the cylinder (411) in a sealing way, and the 2 nd end cover (413) is matched and fixed with the lower end of the cylinder (411) in a sealing way.

8. The circuit breaker of claim 7, wherein: the insulation cylinder (200) comprises an insulator (210), an upper shaft rod (220) and a lower shaft rod (230); the insulator (210) is columnar, and a plurality of sheds suitable for increasing the insulation creepage distance are arranged on the side surface of the insulator; the upper shaft (220) is fixed to the upper end of the insulator (210), and the lower shaft (230) is fixed to the lower end of the insulator (210).

9. The circuit breaker of claim 8, wherein: the electromagnetic driver (300) comprises a cylindrical driver cylinder body (310), a driver upper end cover (320), a driver lower end cover (330), an iron core (360) and a driver output shaft (370), wherein a 1 st caulking groove (311) and a 2 nd caulking groove (312) which surround along the circumferential direction are arranged on the inner side wall of the driver cylinder body (310), the 1 st caulking groove (311) is arranged at the upper end part of the cylinder body (310), and the 2 nd caulking groove (312) is arranged at the lower end part of the cylinder body (310); a 1 st coil (340) is assembled in the 1 st embedded groove (311), and a 2 nd coil (350) is assembled in the 2 nd embedded groove (312); the iron core (360) is arranged in the cylinder body (310) and sleeved outside the driver output shaft (370) and fixed, the upper end cover (320) of the driver is fixed with the upper end of the cylinder body (310), the lower end cover (330) of the driver is fixed with the lower end of the cylinder body (310), the upper end part of the driver output shaft (370) penetrates through a middle through hole of the upper end cover (320) of the driver and extends out, and the lower end part of the driver output shaft penetrates through a middle through hole of the lower end cover (330) of the driver and extends out.

10. The circuit breaker according to any one of claims 1-9, wherein: the number of the single-pole switches is 1, 2, 3 or more.