CN218160211U

CN218160211U - Direct current arc extinguishing device and circuit breaker

Info

Publication number: CN218160211U
Application number: CN202222346731.4U
Authority: CN
Inventors: 高腾飞; 令狐绍江; 张澳; 臧卫; 袁辉; 范奇文; 邓明凯; 吴超鹏
Original assignee: Shanghai Tianyixing Intelligent Electric Co ltd; Zhejiang Tengen Intelligent Electrical Appliance Co ltd; Zhejiang Tengen Electric Co Ltd
Current assignee: Shanghai Tianyixing Intelligent Electric Co ltd; Zhejiang Tengen Intelligent Electrical Appliance Co ltd; Zhejiang Tengen Electric Co Ltd
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2022-12-27
Anticipated expiration: 2032-09-05

Abstract

The utility model discloses a direct current arc control device and circuit breaker, it includes: one end of the insulating cover is provided with an opening, the other end of the insulating cover is provided with a slit, and a first cavity is formed on the upper side of the insulating cover; the arc extinguishing chamber is arranged in the first cavity, the corresponding opening direction of the arc extinguishing chamber is set to be an air outlet side, and the other end of the arc extinguishing chamber is set to be an arc striking side; the arc isolation plate is arranged at the opening of the insulating cover, a plurality of exhaust through holes are arrayed on the surface of the arc isolation plate, and a gap for high-temperature gas reflected by the arc isolation plate to flow back to the arc striking side of the arc extinguishing chamber is formed between the outer side of the arc extinguishing chamber and the inner side of the insulating cover. The utility model discloses can be with the high temperature gas by the flash barrier reflection, through the arc initiation end of airflow channel backward flow to the explosion chamber, utilize airflow channel's heat transfer and convection action, reduce the temperature of high temperature air current, avoided because the phenomenon that high temperature air current leads to puncturing behind one's back piling up in the end of giving vent to anger takes place, and through forming the air current circulation, promote electric arc with higher speed and remove to the explosion chamber direction fast, improve arc extinguishing efficiency.

Description

Direct current arc extinguishing device and circuit breaker

Technical Field

The utility model particularly relates to a direct current arc control device and circuit breaker.

Background

The circuit breaker is installed on a main circuit to cut off the main circuit when an overload or a short circuit occurs in the main circuit. When the main circuit of the circuit breaker is cut off, the moving contact and the static contact in the circuit breaker are quickly disconnected, at the moment, the air medium is discharged due to the voltage between the moving contact and the static contact, so that high-temperature electric arcs are generated, and the air temperature in the arc extinguishing device is sharply increased in the burning process of the electric arcs, so that air ionization is accelerated. On the other hand, the electric arc is divided into a plurality of short arcs by a plurality of arc isolating grid pieces under the pushing of the magnetic field and the fluid effect in the arc extinguishing chamber, the deionization effect of the electric arc is enhanced by the metal arc isolating pieces, the electric arc is reduced, the voltage is rapidly increased, and the electric arc is extinguished. In order to improve the arc extinguishing performance of the arc extinguishing chamber, generally, the electric arc is rapidly introduced into the arc extinguishing grid plate of the arc extinguishing chamber, so that the grid plate effectively cuts the electric arc, and the effect of rapidly extinguishing the electric arc is achieved.

In order to make the electric arc enter the arc extinguish chamber rapidly, the air-blast or magnetic-blast technology is usually adopted, for example, chinese patent CN 112420462A discloses a contact arc extinguishing device of a circuit breaker, which specifically discloses: the arc separation cover (33) is provided with a first arc baffle (331) and a second arc baffle (332) on two sides close to the movable contact (2), a narrow cavity (333) for accommodating the movement of the movable contact (2) is formed between the first arc baffle (331) and the second arc baffle (332), a top plate (336) is arranged on the narrow cavity (333), the top plate (336) is abutted against the arc striking grid sheet (321) to form a closed part for closing the upper space of the arc extinguishing device (3), an exhaust port (3361) is arranged on the closed part, and the exhaust port (3361) corresponds to a gap between the movable contact (2) and the arc striking grid sheet (321) when the movable contact (2) is in an opening position. According to the technical scheme, through a strong magnetism increasing arc striking and air blowing composite technology, an arc striking grid sheet and an arc extinguishing grid sheet close to the arc striking grid sheet form a composite magnetism increasing effect on electric arcs and arc roots at the opening position of a moving contact, magnetic blowing force is improved, the existing arc extinguishing chamber discharges a circuit breaker shell through a rear arc baffle plate, when high-temperature air flow generated by the electric arcs in the opening and closing process directly acts on the arc baffle plate at the rear end of the arc extinguishing chamber, part of the high-temperature air flow can be discharged through the arc baffle plate, and part of the high-temperature air flow can be reflected back and accumulated at the rear part of the arc extinguishing chamber, so that the internal temperature is improved, the risk of re-striking the electric arcs is increased, the risk of back breakdown is increased, as can be known from a test curve diagram of fig. 1, when a 40kA short-circuit breaking current test is carried out on the existing circuit breaker, the continuous arc striking phenomenon caused by trailing after breaking can occur, and test failure is caused. Therefore, how to avoid the continuous arcing phenomenon caused by the tailing after the separation is extremely important.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art exists, the utility model aims to provide a direct current arc control device and circuit breaker.

In order to achieve the above purpose, the utility model provides a following technical scheme:

a dc arc extinguishing device, comprising:

the circuit breaker comprises an insulating cover, a first switch, a second switch and a switch, wherein the insulating cover is arranged in a base of the circuit breaker, one end of the insulating cover is provided with an opening, the other end of the insulating cover is provided with a slit capable of accommodating the movement of a moving contact, and a first cavity for accommodating an arc extinguish chamber is formed on the upper side of the insulating cover;

the arc extinguishing chamber is arranged in the first cavity, the corresponding opening direction of the arc extinguishing chamber is set to be an air outlet side, and the other end of the arc extinguishing chamber is set to be an arc striking side;

an arc baffle plate arranged at the opening of the insulating cover, and a plurality of exhaust through holes are arrayed on the surface of the arc baffle plate,

and a gap for high-temperature gas reflected by the arc isolating plate to flow back to the arc striking side of the arc extinguishing chamber is formed between the outer side of the arc extinguishing chamber and the inner side of the insulating cover.

The arc extinguishing chamber includes two arc-isolating side plates and a plurality of array settings arc extinguishing bars piece between two arc-isolating side plates, and the one end that each arc extinguishing bars piece is close to the arc-isolating plate is apart from the distance of arc-isolating plate and varies.

The bilateral symmetry of striking side is equipped with the gas production cover, forms the narrow cavity that is used for holding the moving contact motion between two gas production covers, the gas production cover includes the installation department that sets up and sets up a plurality of interval distribution's of installation department one side with the installation face laminating of the arc-isolating curb plate of explosion chamber arc claw, the arc claw extends towards installation face direction, the thickness of arc claw is suitable for inserting between two adjacent arc extinguishing bars piece in the explosion chamber, and the spacing distance between two adjacent arc claws is suitable for the arc extinguishing bars piece that holds a slice explosion chamber.

The opposite surfaces of the gas generating cover are arranged into a concave-convex-concave structure along the vertical direction, and the concave-convex-concave structure and the convex-concave structure are formed oppositely:

the first channel is arranged at the lower side of the gas production cover and is used for pushing the electric arc to move upwards or towards the gas outlet side by gas generated by the gas production cover when the movable and static contacts are disconnected;

the second channel is arranged on the upper side of the gas production cover and used for lengthening the electric arc by utilizing pressure gradient change when the electric arc moves upwards;

the connecting channel is used for connecting the first channel and the second channel, and the gap between the connecting channel and the second channel is smaller than that between the first channel and the second channel.

The opposite surfaces of the gas generating covers are arranged into a concave-convex structure along the horizontal direction, and the two gas generating covers are formed oppositely:

and the third channel drives the reflowing high-temperature gas to drive the electric arc to enter the arc extinguishing chamber in an accelerating manner by utilizing the pressure gradient change.

The boundary line of the concave surface and the convex surface of the concave-convex structure is an arc line, and the center of the arc line is located at the end of the concave surface.

The arc striking grid is arranged at the top end of the arc extinguishing chamber and provided with a plurality of vent holes arranged in an array.

A second cavity used for coating the static contact assembly is arranged on the lower side of the bottom of the insulating cover, and a through hole used for exposing the silver contact is formed between the second cavity and the first cavity.

And a primary and a secondary grooves which are matched with each other are arranged between the insulating cover and the base of the circuit breaker.

A circuit breaker with the direct current arc extinguishing device comprises a circuit breaker body, wherein the direct current arc extinguishing device is arranged between a moving contact and a fixed contact assembly of the circuit breaker body.

The utility model has the advantages that: the utility model discloses an insulating boot can form an independent cavity at the circuit breaker base, utilize the clearance between explosion chamber and the insulating boot to form airflow channel, can be with the high-temperature gas by the flash barrier reflection, via airflow channel backward flow to the striking end of explosion chamber, utilize airflow channel's heat transfer and convection action, reduce the temperature of high-temperature air current, avoided because the phenomenon that leads to puncturing behind one's back is piled up to high-temperature air current in the end of giving vent to anger takes place, and through forming the air current circulation, promote electric arc to remove to the explosion chamber direction fast with higher speed, improve arc extinguishing efficiency.

Drawings

Fig. 1 is a graph showing the result of a 40kA short circuit current breaking test performed by a conventional circuit breaker.

Fig. 2 is the utility model discloses a direct current arc extinguishing device is applied to the schematic diagram in the circuit breaker.

Fig. 3 is a schematic view of the dc arc extinguishing device applied to the circuit breaker.

Fig. 4 is a schematic cross-sectional view of the dc arc extinguishing device of the present invention.

Fig. 5 is a schematic cross-sectional view of another angle of the dc arc extinguishing device according to the present invention.

Fig. 6 is a schematic cross-sectional view of the dc arc-extinguishing device along the vertical gas-generating cover direction.

Fig. 7 is a schematic structural view of the insulation cover of the present invention.

Fig. 8 is a schematic view of another angle of the insulation cover according to the present invention.

Fig. 9 is a schematic structural view of the gas production hood of the present invention.

Fig. 10 is a schematic structural view of another angle of the gas production hood of the present invention.

Fig. 11 is a schematic structural view of the static contact assembly of the present invention.

Fig. 12 is an enlarged schematic view of an arc striking angle of the static contact assembly of the present invention.

Fig. 13 and 14 are graphs of short circuit tests of the breaking DC1500V Ics =40kA of the present invention.

In the figure, 1, a base; 2. a DC arc extinguishing device; 3. a moving contact; 4. a primary and a secondary groove; 5. an insulating cover; 6. an arc baffle plate; 7. a limiting groove; 8, an arc extinguishing chamber; 9. a gas circulation channel; 10. a gas generating cover; 11. a stationary contact assembly; 51. a first chamber; 52. a slit; 53. mounting grooves; 54. a fixed seat; 56. a via hole; 57. a second chamber; 58. a groove; 81. arc isolation side plates 82 and arc extinguishing grid plates; 83. an arc striking grid sheet; 101. an installation part; 102. an arc-shaped claw; 103. a first channel; 104. a connecting channel; 105. a second channel; 106. a concavo-convex-concavo structure; 107. a concave-convex structure; 108. a boundary line; 109. a tip; 1010. a concave surface; 1011. a channel; 111. a wiring board; 112 a contact plate; 113. a connecting member; 114. an arc striking angle; 115. a support frame; 116. avoiding the mouth.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, back \8230;) in the embodiments of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

As shown in the figure, the utility model provides a direct current arc control device 2, it includes:

an insulating cover 5, which is arranged in the base 1 of the circuit breaker, one end of which is provided with an opening, the other end of which is provided with a slit 52 that can accommodate the movement of the moving contact 3, and the upper side of the insulating cover forms a first chamber 51 for accommodating an arc extinguishing chamber;

an arc extinguishing chamber 8 which is provided in the first chamber 51, and whose opening direction is set as a gas outlet side and whose other end is set as an arc striking side;

an arc baffle 6 arranged at the opening of the insulating cover and provided with a plurality of exhaust through holes on the surface in an array manner,

The whole insulating boot that can inlay to be established and fix in the base, its front end forms slit 52, and the moving contact can move relative to the slit, and the width of preferred this slit and the width looks adaptation of moving contact, and be less than the width of the striking side of explosion chamber, can play the effect that blocks the high temperature air current of backward flow for it flows in the striking end of explosion chamber via the insulating boot front end inner wall.

And wherein the first cavity bottom of insulating boot is equipped with a mounting panel for place the explosion chamber, and mounting panel one end extends to the opening direction and forms a fixing base 54, and the outside of this fixing base extends the outside, and is equipped with mounting groove 53 on the fixing base for fixed arc 6 that separates, and the inner wall correspondence at the base that just corresponds is equipped with spacing groove 7, the spacing groove slides relatively in the arc baffle both sides, and its lower extreme and mounting groove cooperation utilize arc baffle and insulating boot to fall into independent cavity in with the base.

In order to prevent the high-temperature airflow reflected by the arc baffle from being mixed in disorder in the shell, preferably, a primary-secondary groove is arranged between the insulating cover and the inner wall of the base, and through the arrangement of the primary-secondary groove, the creepage distance can be increased, and the arc breakdown of the static contact is prevented. The primary and secondary grooves are at least one mutually matched lug and groove structure, and the creepage distance between the lug and the groove is increased by utilizing the matching of the lug and the groove.

The gap is formed by an installation gap between the inner wall of the insulating cover and the arc isolating side plate of the arc extinguishing chamber, the rear end of the gap is directly communicated with the gap between the arc extinguishing chamber and the arc isolating plate, the front end of the gap is communicated with the arc striking end of the arc extinguishing chamber through the side walls at the two ends of the slit of the insulating cover, a complete gas circulation channel 9 is further realized, the temperature of high-temperature gas is reduced by utilizing heat transfer in a gas backflow process, the high-temperature gas acts on gas generated by the gas generating cover, the high-temperature gas and the arc striking end drive electric arcs to rapidly move towards the arc extinguishing chamber, and the arc striking effect is improved. Wherein the gas circulates as shown by the direction of the arrows in fig. 5, wherein the solid arrows indicate the moving path of the high temperature gas flow reflected back, and the dotted arrows indicate the moving path of the high temperature gas flow generated by the arc.

The explosion chamber includes two arc-isolating curb plates 81 and a plurality of array settings arc extinguishing bars 82 between two arc-isolating curb plates, and each arc extinguishing bars 82 is close to the one end of arc-isolating plate 6 and varies apart from the distance of arc-isolating plate, preferred each arc extinguishing bars parallel arrangement, and in order to realize the range of more arc extinguishing bars, this application adopts and sets up each arc extinguishing bars along the horizontal plane direction, improve the quantity of arc extinguishing bars piece as far as, increase capacity, can divide the higher short-circuit current of branch.

Meanwhile, arc extinguishing grid pieces opposite to the arc isolating plates are arranged in a staggered manner, as shown in a block A in fig. 4, the distances between each grid piece and the arc isolating plates are different, when gas passes through the grid pieces, different pressure gradients are generated, so that electric arcs rapidly move upwards, and finally the electric arcs are discharged to the outside through holes in the arc isolating plates.

The staggered arc extinguishing chamber enables the distance between the electric arc and the arc extinguishing grid sheet to be different, and can effectively prevent the arc extinguishing chamber from being punctured to form electric arc trailing, so that breaking failure is caused.

After the electric arc is generated, the electric arc moves upwards rapidly through the arc-shaped structure of the insulating cover, and passes through a plurality of spaces (gaps formed by the staggered grid sheets and the arc isolating plates) with different gaps in the moving process, so that the electric arc is accelerated and decelerated by the spaces and finally discharged to the outside of the arc isolating plates.

The top end of the arc extinguishing chamber is provided with an arc striking grid piece 83, and the arc striking grid piece is provided with a plurality of vent holes arranged in an array.

The arc striking grid 83 is designed in a 'pair' form and can guide the arc to the uppermost grid, so that the arc is pulled longer and thinner, and the arc is cooled more quickly, and the arc moving path is shown by an arrow mark in fig. 4.

The bilateral symmetry of striking side is equipped with gas production cover 10, forms the narrow cavity that is used for holding moving contact motion between two gas production covers 10, gas production cover includes the installation department 101 that sets up with the installation face laminating of the arc-isolating side plate of explosion chamber and sets up a plurality of interval distribution's of installation department one side arc claw 102, the arc claw extends towards installation face direction, the thickness of arc claw is suitable for inserting between two adjacent arc extinguishing bars piece in the explosion chamber, and the spacing distance between two adjacent arc claws is suitable for the arc extinguishing bars piece that holds an explosion chamber. And a channel with big front end and big back end and small middle part is formed between the arc claws at the two sides.

Wherein one side of installation department 101 towards the installation face is equipped with a plurality of passageways 1011, the open end of arc extinguishing bars piece is inserted and is located this passageway, and this passageway is located between two arc claws, and its width is with the thickness looks adaptation of arc extinguishing bars piece.

Because one side of the gas generating cover is fixedly connected with the arc isolating side plate, the electric arc can only contact with the surface of one side of the gas generating cover, a large amount of gas is generated after the gas generating cover contacts with the electric arc, high voltage is formed at the arc striking side of the arc extinguish chamber, the high voltage gas further accelerates through the shrinkage type arc channel to drive the electric arc to rapidly enter the arc extinguish chamber, the high voltage gas diffuses to the two sides of the arc extinguish device along the surface of the arc claw after entering the arc extinguish chamber, the high voltage gas moves along the extending direction of the arc claw, namely, the front arc claw like the comb-shaped tooth shape suddenly compresses the gas space, the pressure gradient is increased, and the arc claws form an arc-shaped structure to form a small-large pressure gradient, so that the electric arc can smoothly enter the arc extinguish chamber.

The opposite surfaces of the gas generating cover are arranged into a concave-convex-concave structure 106 along the vertical direction, and the concave-convex-concave structure and the convex-concave structure are formed oppositely:

the first channel 103 is arranged at the lower side of the gas production cover and is used for pushing the electric arc to move upwards or towards the direction of the gas outlet side by gas generated by the gas production cover when the moving contact and the static contact are disconnected; when the movable and static contacts are opened, the electric arc ablates the gas generating cover, the generated gas pushes the electric arc to move upwards and forwards, the electric arc moves upwards to enable the electric arc to be rapidly elongated, and the electric arc moves forwards to enable the electric arc to enter the arc extinguishing chamber more rapidly;

a second passage 105 provided on an upper side of the gas generating cover for elongating the arc by using a pressure gradient change when the arc moves upward;

the connecting channel 104 is used for connecting the first channel and the second channel, and the gap between the connecting channel and the second channel is smaller than the gap between the first channel and the second channel.

The junction of the first channel and the connecting channel is in smooth transition, so that resistance is reduced, and the electric arc can move upwards more quickly.

In the process that the electric arc moves upwards, when the electric arc passes through the connecting channel, the space is suddenly reduced, so that the pressure gradient difference is increased, when the electric arc moves to the second channel, the space is suddenly increased, the pressure gradient is reduced, and through the change of small-large-small pressure gradient, the electric arc can quickly move upwards to be elongated, and the air flow can quickly reach the upper part of the arc extinguish chamber by matching with the uppermost open arc striking grid piece.

The opposite surfaces of the gas generating covers are arranged into a concave-convex structure 107 along the horizontal direction, and the two gas generating covers are formed oppositely:

and the third channel drives the reflowing high-temperature gas to drive the electric arc to enter the arc extinguish chamber in an accelerating manner by utilizing the pressure gradient change.

The boundary 108 between the concave surface 1010 and the convex surface of the concave-convex structure is an arc line, and the center of the arc line is located at the end of the concave surface. The arc is provided to ensure smooth surface, so that the aerodynamic drag coefficient is reduced to ensure smooth transition of the airflow, and a tip 109 is preferably provided at a position close to the stationary contact assembly in the direction of the concave surface to reduce the resistance to airflow.

After high-temperature airflow generated by electric arc in the breaking process passes through the arc extinguish chamber, one part of the high-temperature airflow is exhausted through the air holes of the arc isolating plate, one part of the high-temperature airflow is reflected back by the arc isolating plate and returns to the contact area through the airflow channel, the hot airflow is subjected to heat transfer and convection action through the airflow channel, the temperature is greatly reduced, the back breakdown phenomenon can be relieved after the hot airflow enters the contact area, the pressure gradient is reduced when the returned airflow passes through the third channel, the pressure gradient is increased in the forward moving process, the pressure gradient is increased when the hot airflow passes through the fourth channel formed by the arc-shaped claws, and the airflow is continuously accelerated in the process from the third channel to the fourth channel, so that the electric arc is pushed to rapidly move towards the arc extinguish chamber.

And a second cavity 57 for coating the static contact assembly 11 is arranged at the lower side of the bottom of the insulating cover, and a through hole 56 for exposing the silver contact is arranged between the second cavity and the first cavity. The whole static contact component is placed in the second chamber, the silver contact is only exposed at the via hole, or the silver contact and the arc striking angle 114 are exposed at the via hole, and the rest parts are all wrapped by the insulating cover, so that the overall dielectric performance of the product is improved, and the static contact component can only move along the direction of the arc striking angle to prevent mixed movement.

The side of the contact plate facing the wiring board is provided with an arc striking angle 114, the arc striking angle is fixedly connected with the contact plate through a support part 115, and the arc striking angle directly extends on the contact plate, so that electric arcs generated when the moving contact and the static contact are switched on and off can be better guided to the deep part of the arc extinguish chamber. In addition, a split structure is adopted, so that the processing is more convenient, and the product reliability can be ensured. The utility model discloses a support piece, including support piece, arc ignition angle and contact board, locating piece, U-shaped structure, locating hole, locating piece, contact board, locating piece, support piece both ends are the U type respectively, the both ends fixed connection of arc ignition angle and contact board equal part and support piece, just the arc ignition angle extends to both sides towards the both sides of contact board and forms the locating piece, the U type structure at support piece both ends forms a constant head tank in vertical direction, the locating hole can be arranged in the constant head tank, and when the arc ignition angle was arranged in on this support piece, its terminal and the laminating of the one end of contact board set up, just the arc ignition angle upwards inclines slightly, and its inclination aligns with the concavity of the striking grid piece of downside, is convenient for introduce arc into the depths of arc extinguishing grid piece.

Meanwhile, an avoiding port 116 for avoiding an arc striking angle is formed in the wiring board towards the direction of the contact plate, so that the arc striking angle is prevented from being directly arranged above the contact plate.

The utility model also provides a circuit breaker with above-mentioned direct current arc control device, it includes the circuit breaker body, be equipped with above-mentioned direct current arc control device between the moving contact of circuit breaker body and the static contact subassembly.

Through set up above-mentioned direct current arc control device between each moving contact and fixed contact subassembly, can effectually avoid the appearance of breakdown phenomenon behind one's back.

As shown in fig. 13 and 14, through a short circuit breaking test of DC1500V Ics =40kA, from a test curve, the circuit breaker can effectively solve the back breakdown phenomenon caused by the continuous arcing phenomenon due to the tail, so that the circuit breaker is more reliable and safer in short circuit protection.

The examples should not be construed as limiting the present invention, but any modifications made based on the spirit of the present invention should be within the scope of the present invention.

Claims

1. A direct current arc control device which characterized in that: it includes:

an arc baffle arranged at the opening of the insulating cover and provided with a plurality of exhaust through holes on the surface in an array manner,

2. The dc arc extinguishing device according to claim 1, wherein: the arc extinguishing chamber includes two arc-isolating side plates and a plurality of array settings arc extinguishing bars piece between two arc-isolating side plates, and the one end that each arc extinguishing bars piece is close to the arc-isolating plate is apart from the distance of arc-isolating plate and varies.

3. The dc arc extinguisher of claim 1, wherein: the bilateral symmetry of striking side is equipped with the gas production cover, forms the narrow cavity that is used for holding the moving contact motion between two gas production covers, the gas production cover includes the installation department that sets up and sets up a plurality of interval distribution's of installation department one side with the installation face laminating of the arc-isolating curb plate of explosion chamber arc claw, the arc claw extends towards installation face direction, the thickness of arc claw is suitable for inserting between two adjacent arc extinguishing bars piece in the explosion chamber, and the spacing distance between two adjacent arc claws is suitable for the arc extinguishing bars piece that holds a slice explosion chamber.

4. A dc arc quenching device according to claim 3, characterized in that: the opposite surfaces of the gas generating cover are arranged into a concave-convex-concave structure along the vertical direction, and the concave-convex-concave structure and the convex-concave structure are formed oppositely:

the second channel is arranged on the upper side of the gas generating cover and used for lengthening the electric arc by utilizing the pressure gradient change when the electric arc moves upwards;

5. The dc arc extinguisher of claim 3, wherein: the opposite surfaces of the gas generating covers are arranged into a concave-convex structure along the horizontal direction, and the two gas generating covers are formed oppositely:

6. The dc arc extinguishing device of claim 5, wherein: the boundary line of the concave surface and the convex surface of the concave-convex structure is an arc line, and the center of the arc line is located at the end of the concave surface.

7. The dc arc extinguishing device according to claim 2, wherein: the top of explosion chamber is equipped with the striking bars piece, the striking bars piece is equipped with the air vent that a plurality of arrays set up.

8. The dc arc extinguishing device according to claim 1, wherein: and a second cavity for coating the static contact assembly is arranged at the lower side of the bottom of the insulating cover, and a through hole for exposing the silver contact is arranged between the second cavity and the first cavity.

9. The dc arc extinguishing device according to claim 1, wherein: and a primary and a secondary grooves which are matched with each other are arranged between the insulating cover and the base of the circuit breaker.

10. A circuit breaker provided with a dc arc extinguishing device according to any one of claims 1 to 9, comprising a circuit breaker body, characterized in that: the direct current arc extinguishing device is arranged between the moving contact and the fixed contact assembly of the circuit breaker body.