CN113539745A

CN113539745A - Arc extinguishing system of direct current contactor

Info

Publication number: CN113539745A
Application number: CN202010311283.7A
Authority: CN
Inventors: 李思泓; 孙吉升; 张森林; 贾峰; 张慧民
Original assignee: Shanghai Electrical Apparatus Research Institute Group Co Ltd
Current assignee: Shanghai Electrical Apparatus Research Institute Group Co Ltd
Priority date: 2020-04-20
Filing date: 2020-04-20
Publication date: 2021-10-22

Abstract

The invention relates to an arc extinguishing system of a direct current contactor, and belongs to the technical field of direct current contactors. The direct current contactor comprises a contact system, an arc extinguishing system, an electromagnetic system and a shell; the arc extinguishing system comprises an arc extinguishing chamber, an arc striking device and an arc isolating device; the moving contact and the arc extinguish chamber of the contact system are provided with arc striking devices; an arc isolating device is arranged in the shell. On the premise of a certain product volume, the arc extinguishing chamber structure is improved, the arc striking device and the arc isolating device are additionally arranged, and arc extinguishing is carried out by fully utilizing a limited inner space. And the air flue circulation and diffusion of high-temperature arc gas in the contactor cavity are realized, the arc cooling effect is enhanced, the pollution of the main cavity is avoided, and the arc extinguishing capability is further improved. High-temperature gas generated between the moving contact and the static contact on the two sides of the contact bridge flows in respective gas flow channels. And under the condition of short-circuit fault, the risk of contact fusion welding is reduced, and the contact reliability is improved.

Description

Arc extinguishing system of direct current contactor

Technical Field

The invention relates to an arc extinguishing system of a direct current contactor, and belongs to the technical field of direct current contactors.

Background

The dc contactor is a contactor used in a dc circuit, and is mainly used for controlling a dc circuit (a main circuit, a control circuit, an excitation circuit, and the like). The dc contactor needs to frequently switch a large load current, so it must have a strong arc extinguishing capability, and a flexible contact system and a reliable electromagnetic system.

In the field of new energy application, for example, a pure electric vehicle generally adopts a high-voltage direct-current contactor to be responsible for switching on and off a power battery system, and can switch off the high-voltage battery system when an accident occurs. The electric contact can have discharge phenomenon and produce electric arc in the process from switch-on to disconnection, the production of electric arc can delay the disconnection of circuit, higher electric arc energy can burn the electric contact even, causes the electric contact to melt and weld, and because present direct current contactor all adopts sealed form, can lead to the explosion that catches fire of switching apparatus under the severe condition.

In the prior art, in order to make a direct current contactor product have small volume and high operation load, a high-voltage direct current contactor generally adopts a sealed gas-filled external magnetic field to transversely elongate a metal phase electric arc, and the electric arc is rapidly cooled and compounded in an arc extinguishing medium to be dissociated. Under the general condition, the technical means has limited arc extinguishing space, longer arc burning time, lower arc extinguishing capacity, higher electrical service life index promotion difficulty, and the generated metal particles and carbonized impurities are gathered in an arc extinguishing cavity in the arc extinguishing process to pollute the cavity, thus easily causing the reduction of the insulating capability after the electrical service life to a certain degree. For example: at present, manufacturers in Taike, Panasonic, LS and the like in the market all apply magnetic quenching technical means, and under the condition of high-grade breaking, the service life capacity is suddenly reduced, even explosion can occur.

The internal structure of the high-voltage direct-current contactor which is common at present is shown in attached figures 1a and 1 b. In the prior patent literature, chinese patent publication nos. CN102074387A and CN104412353A disclose typical structural arrangements of two types of high-voltage dc contactors, respectively. The disadvantages of this design are: the volume of a cavity at the upper part of the contactor is not fully utilized by a contact arc extinguishing system (fig. 1b is a side view, cavities at two sides of a movable contact bridge are isolated from the contact arc extinguishing system, the cavities are not effectively utilized), arc extinguishing capacity is limited, and meanwhile, the arc extinguishing capacity is difficult to continue to be improved and arc burning time is shortened only by means of a permanent magnet magnetic arc quenching technology under a gas atmosphere condition. The arc extinguishing chamber adopts square closed cavity, and the arc extinguishing passageway is long and narrow, and the unable circulation that flows of high temperature arcing gas appears easily under the disjunction of higher grade and the unable effluvium of arcing gas and cool off fast, and the inner chamber pressure is too big causes the product explosion.

In the field of application of existing new energy, a power battery system is generally 400VDC and can be greatly improved in the future, so that the high-voltage direct-current contactor needs stronger arc extinguishing capability, can safely turn on and off relatively large current, and can avoid damage of fusion welding and excessive arcs to contacts in the contactor. Therefore, the technical field urgently needs to adopt an arc extinguishing device in the direct current contactor so as to realize an efficient and reliable arc extinguishing effect.

Disclosure of Invention

The invention aims to solve the technical problem of realizing efficient and reliable arc extinguishing action in a direct current contactor.

In order to solve the above problems, the technical solution adopted by the present invention is to provide an arc extinguishing system of a dc contactor, wherein the dc contactor comprises a contact system, an arc extinguishing system, an electromagnetic system and a housing; a contact system, an arc extinguishing system and an electromagnetic system are arranged in the shell; the contact system comprises a fixed contact and a movable contact; the electromagnetic system comprises a driving middle shaft, a static iron core, a movable iron core, a framework coil, a metal cup and a yoke iron; a contact system is arranged above the electromagnetic system, and an arc extinguishing system is arranged at the periphery of the contact system; the arc extinguishing system comprises an arc extinguishing chamber, an arc striking device and an arc isolating device; the arc extinguish chamber is arranged on the outer periphery of a relative motion area between a moving contact and a fixed contact of the direct current contactor and between the two fixed contacts; the moving contact and the arc extinguish chamber are provided with arc striking devices; an arc isolating device is arranged in the shell.

Preferably, the arc striking device comprises an arc striking part arranged on the moving contact and an arc striking sheet arranged on the arc extinguishing chamber; the moving contact is provided with an arc striking part extending to the arc extinguishing chamber; and one end of the arc extinguish chamber close to the static contact is provided with an arc striking sheet extending towards the static contact.

Preferably, the arc striking portion of the movable contact is a bent portion bent and extended from the plane of the movable contact toward the arc extinguishing chamber in a direction in which the arc path is generated.

Preferably, the arc extinguish chamber is provided with grid sheets which are arranged in a layered and parallel manner, and the grid sheets are provided with bent heads along the direction of generating an arc path; the grid piece is provided with an arc striking groove corresponding to the arc striking part of the moving contact; the arc extinguishing chamber top is equipped with the striking plate, and the striking plate is close to the one end of static contact and is also equipped with crooked head along the same direction of the crooked head of grid piece along the direction that produces the electric arc route, and the crooked head length of striking plate is greater than the crooked head length of grid piece.

Preferably, the arc isolation device comprises an arc extinguishing cavity and an arc isolation plate arranged on the moving contact driving middle shaft; the arc extinguishing cavity is cylindrical with the driving middle shaft as a central axis, and an arc extinguishing chamber and a contact system are arranged in the arc extinguishing cavity; one end of the cylindrical arc extinguishing cavity close to the moving contact is provided with an opening, and the other end of the cylindrical arc extinguishing cavity is provided with a substrate; the cylindrical arc extinguishing cavity is provided with a continuous cylindrical wall; two sections of arc-shaped partition plates which are symmetrically arranged relative to the center of the driving center shaft are arranged on the substrate and are perpendicular to the substrate; the moving contact top be equipped with the flash barrier of perpendicular to moving contact plane, the intermediate position at moving contact top portion is located to the flash barrier, separates two spaces with two contacts that the moving contact contacted with the static contact.

Preferably, the cylindrical wall of the cylindrical arc extinguishing cavity is formed by four right-angle fan-shaped arc surfaces with two different diameters which are arranged at intervals, and the joint of the two right-angle fan-shaped arc surfaces with different diameters is arranged on the connecting line of the two static contacts.

Preferably, the substrate is provided with a through hole penetrating through the two static contacts, and two sections of arc-shaped clapboards perpendicular to the substrate are symmetrically arranged between the through holes of the two static contacts and between the arc extinguish chamber and the moving contact relative to the center of the driving central shaft; one end of the arc-shaped partition board, which is far away from the bent head of the arc striking plate, is close to the fixed contact on one side, and the other end of the arc-shaped partition board is arranged on the outer side of the region, opposite to the fixed contact, of the bent head of the arc striking plate.

Preferably, the arc-shaped partition board is provided with a guiding portion, and a gap formed between the guiding portion of the arc-shaped partition board on the side close to the static contact and the cylindrical wall of the cylindrical arc extinguishing cavity is gradually reduced when the guiding portion of the arc-shaped partition board on the side close to the static contact is gradually close to the static contact.

Preferably, the two sections of arc-shaped partition plates are respectively provided with two corresponding rib plates perpendicular to the base plate and used for limiting the motion guidance of the moving contact, the rib plates arranged on the same section of arc-shaped partition plate are arranged on two sides equidistant to the driving center shaft, and the corresponding rib plates and the arc-isolating plate of the driving center shaft form an isolating structure for isolating two contacts, which are in contact with the moving contact and the static contact, in two spaces.

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

the technical scheme of the invention solves the defects that the arc extinguishing capacity is limited, the arc extinguishing chamber adopts a square closed cavity, the arc extinguishing channel is long and narrow, high-temperature arc gas cannot flow and circulate, the arc gas cannot escape and be rapidly cooled under the high-grade breaking, and the pressure of an inner cavity is overlarge to cause product explosion in the prior art. Under the prerequisite that the product volume is certain, improve the explosion chamber structure, increase striking device and separate arc device structure, the arc extinguishing of make full use of limited inner space. In the limited cavity space, the arc extinguishing capability is improved. And the air flue circulation and diffusion of high-temperature arc gas in the contactor cavity are realized, the arc cooling effect is enhanced, the pollution of the main cavity is avoided, and the arc extinguishing capability is further improved. High-temperature gas generated between the moving contact and the static contact on the two sides of the contact bridge flows in respective gas flow channels. And under the condition of short-circuit fault, the risk of contact fusion welding is reduced, and the contact reliability is improved.

Drawings

Fig. 1a and 1b are typical structures of a prior art high voltage direct current contactor;

FIG. 2a is a top view of the overall structure of the arc extinguish chamber cavity of the invention;

FIG. 2b is an elevational view of the overall construction of the present invention;

FIG. 2c is a side view of the overall structure of the present invention;

FIG. 2d is a schematic diagram of the internal structure of the contact quenching system of the present invention;

FIG. 3a is a top view of the arc chute and arc chamber assembly of the present invention;

FIG. 3b is a schematic diagram of the arc extinguishing chamber of the present invention;

FIG. 4a is a schematic structural diagram of the movable contact bridge of the present invention;

FIG. 4b is a perspective view of the moving contact structure of the present invention;

FIG. 5a is a schematic view of the arc chute of the present invention;

FIG. 5b is a schematic view of an arc chute of the present invention;

FIG. 5c is a schematic view of an arc chute strike of the present invention;

FIG. 6a is an embodiment of a permanent magnet and arc chute arrangement of the present invention;

FIG. 6b is another embodiment of a permanent magnet and arc chute arrangement of the present invention;

fig. 7a,7b and 7c are schematic structural views of the high-voltage direct-current contactor provided with the flash barrier.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings:

the invention provides an arc extinguishing system of a direct current contactor, wherein the direct current contactor comprises a contact system, an arc extinguishing system, an electromagnetic system and a shell 213; a contact system, an arc extinguishing system and an electromagnetic system are arranged in the shell 213; the contact system comprises

static contacts

202 and 203 and a movable contact 204; the electromagnetic system comprises a driving middle shaft 205, a static iron core 206, a movable iron core 207, a framework coil 208, a metal cup 209 and a yoke 214; a contact system is arranged above the electromagnetic system, and an arc extinguishing system is arranged at the periphery of the contact system; the arc extinguishing system comprises

arc extinguishing chambers

210 and 211, an arc striking device and an arc isolating device; the arc extinguish

chambers

210 and 211 are arranged between the two fixed contacts at the outer periphery of the relative motion area between the moving contact 204 and the fixed

contacts

202 and 203 of the direct current contactor; the moving contact and the arc extinguish chamber are provided with arc striking devices; an arc isolating device is arranged in the shell. The arc striking device comprises an arc striking part 2043 arranged on the moving contact 204 and an arc striking sheet 2103 arranged on the arc extinguishing chamber; an arc striking part 2043 extending to the arc extinguishing chamber is arranged on the moving contact; and one end of the arc extinguish chamber close to the static contact is provided with an arc striking sheet 2103 extending towards the static contact. The arc striking portion 2043 of the movable contact is a bent portion that is bent and extended from the driven contact plane toward the arc extinguishing chamber in a direction in which the arc path is generated. The arc extinguish chamber is provided with grid pieces 2101 which are arranged in parallel in a layered way, and the grid pieces are provided with bent heads 2101a along the direction of generating an arc path; an arc striking groove 2101c is formed in an arc striking part 2043 of the movable contact corresponding to the grid piece; the arc striking plate 2103 is arranged at the top end of the arc extinguishing chamber, a bent head 2103a is also arranged at one end of the arc striking plate close to the static contact along the direction of an arc generating path and the same direction of the bent head of the grid plate, and the length of the bent head 2103a of the arc striking plate is greater than that of the bent head 2101a of the grid plate. The arc isolating device comprises an arc extinguishing cavity 215 and an arc isolating plate 3041 arranged on the moving contact driving middle shaft; the arc extinguishing cavity 215 is cylindrical with the driving central shaft as a central axis, and an arc extinguishing chamber and a contact system are arranged in the arc extinguishing cavity; one end of the cylindrical arc extinguishing cavity 215 close to the moving contact is opened, and the other end is provided with a substrate 2151; the cylindrical arc extinguishing cavity is provided with continuous

cylindrical walls

2153, 2152; two sections of arc-shaped partition plates 2154 which are symmetrically arranged relative to the center of the driving center shaft are arranged on the substrate and are vertical to the substrate; the top end of the moving contact is provided with an arc isolating plate 3041 which is perpendicular to the plane of the moving contact, the arc isolating plate 3041 is arranged in the middle of the top end part of the moving contact, and two contacts of the moving contact and a static contact are separated in two spaces. The cylindrical wall of the cylindrical arc extinguishing cavity is formed by four right-angle fan-shaped arc surfaces with two diameters arranged at intervals, and the joint of the two right-angle fan-shaped

arc surfaces

2153 and 2152 with different diameters is arranged on the connecting line of the two static contacts. The base plate is provided with a through hole 2155 through which the two static contacts penetrate, and two arc-shaped clapboards 2154 vertical to the base plate are symmetrically arranged between the through holes of the two static contacts and between the arc extinguish chamber and the moving contact relative to the center of the driving central shaft; one end of the arc-shaped partition plate 2154, which is far away from the arc-striking piece bent head 2103a, is close to the fixed contact on one side, and the other end of the arc-shaped partition plate 2154 is arranged outside the area of the arc-striking piece bent head 2103, which is opposite to the fixed contact on the other side. The arc-shaped partition plate 2154 is provided with a guide part, and a gap formed between the guide part on the side of the arc-shaped partition plate close to the static contact and the cylindrical wall of the cylindrical arc extinguishing cavity 215 is gradually reduced when the guide part is gradually close to the static contact. The two sections of arc-shaped partition plates 2154 are respectively provided with two corresponding rib plates 2156 which are perpendicular to the base plate and used for limiting the motion guidance of the moving contact, the rib plates 2156 arranged on the same section of arc-shaped partition plate are arranged on two sides which are equidistant to the driving center shaft, and the corresponding rib plates 2156 and the arc partition plate 3041 of the driving center shaft form a partition structure which partitions two contacts, which are in contact with the moving contact and the static contact, into two spaces.

It is known from the gas movement and heat conduction that the high-temperature and high-pressure gas always moves to the low-temperature and low-pressure environment, so that the high-temperature and high-pressure gas generated by the arc moves to the outlet of the arc extinguishing chamber along the same direction, which is favorable for the blowing and rapid movement of the arc for cooling, and it is very important that the arc moves rapidly forward in the contactor and spreads in the arc extinguishing chamber, which is favorable for lengthening and cooling the arc, especially in the contactor for direct current application, which has no voltage current zero crossing process, so that lengthening and rapid cooling of the arc become the most important arc extinguishing means.

On the basis of the existing magnetic quenching and product volume being certain, the invention adopts the arc-shaped permanent magnet and arranges the grid arc-extinguishing chamber in the limited space. The arc is cut into a plurality of short arcs through the arc extinguish chamber grid plate, so that the initial dielectric strength of an arc gap is improved, and meanwhile, the grid plate (such as a copper grid plate, a ferromagnetic grid plate, ceramic and the like) has the functions of strengthening cooling and surface recombination. For high-current breaking (such as rated current), the magnetic driving force generated by the grid arc-extinguishing chamber and the magnetic field generated by the permanent magnet (fleming's rule) stretch the arc, the arc with the extended length can be cooled by gas atmosphere (air, nitrogen or hydrogen, etc.), and meanwhile, the arc-burning gas is driven by the pressure gradient of the arc-extinguishing system to be discharged to the two sides of the preset flow channel cavity. Finally, the stretching and cooling of another fracture arc is further enhanced by the circulation of the arcing gas, and the whole circulation process is similar to the form of a 'Taiji diagram'. The mode that this scheme adoption was given vent to anger similar to the inner chamber alleviates the pressure coefficient of explosion chamber greatly, reduces product explosion risk to can make the effective flow circulative cooling of high temperature arcing gas. So not only make it possess bigger arc extinguishing space, shorter arcing time, higher arc voltage to the gaseous flow of arcing is with metal particle and carbonization impurity gathering at explosion chamber cavity rear portion, guarantees the cleanliness factor and the insulation resistance of main cavity body. Further, the arc extinguishing chamber housing can prevent deterioration of the magnetic force characteristics of the permanent magnet, and can maintain the function of rapidly and reliably extinguishing the arc for a long period of time.

Example (b):

fig. 2a is a top view of the overall structure of the arc extinguish chamber cavity disclosed by the invention. The arc extinguishing cavity 215 is internally provided with

static contacts

202 and 203, a movable contact 204 and grid

arc extinguishing chambers

210 and 211, and in addition,

permanent magnets

301 and 302 are respectively fixed at the outer side of the arc extinguishing cavity 215. The contact system comprises moving and static contacts (202, 203, 204) for connecting and disconnecting an external direct current load circuit; two ends of the moving contact 204 are respectively contacted with the static contacts (202, 203), which is called a bridge type contact system; the

arc extinguishing chambers

210 and 211 are used for completing arc extinguishing action; the cavity 215 is used to house the contact system, as well as the arc extinguishing chambers (210, 211). High-temperature arcing gas (216, 217) generated by the moving contact and the static contact in the breaking process enters the

arc extinguishing chambers

210 and 211 through the cavity 215, the arc is cut into a plurality of short arcs through the grid plates, so that the initial dielectric strength of the arc gap is improved, and meanwhile, the grid plates (such as copper grid plates, ferromagnetic grid plates, ceramics and the like) have the functions of enhancing cooling and surface recombination. In addition, the magnetic driving force generated by the arc extinguishing chambers (210, 211) and the magnetic field generated by the permanent magnets (fleming's rule) stretch the electric arcs (216, 217), the electric arcs (216, 217) with the extended lengths can be cooled by gas atmosphere (air, nitrogen, hydrogen or the like), and meanwhile, the arc burning gases (216, 217) are driven to be discharged to the two sides by the pressure gradient of the arc extinguishing system to the arc runner cavity preset in the arc extinguishing cavity 215. Finally, the stretching and cooling of a further fracture arc is further enhanced by the circulation of the arcing gas, which is circulated throughout (216, 217) in a manner similar to a "Taiji diagram". And the flowing of the arcing gas gathers metal particles and carbonized impurities at the rear part of the cavity of the arc extinguish chamber, so that the cleanliness and the insulation resistance of the main cavity are ensured.

The direct current contactor comprises a contact arc extinguishing system, an electromagnetic system and a shell;

the contact arc extinguishing system comprises

static contacts

202 and 203, a moving contact 204, an arc extinguishing cavity 215,

arc extinguishing chambers

210 and 211 and a magnetic field regulation device;

the electromagnetic system comprises a central shaft 205, a static iron core 206, a movable iron core 207, a framework coil 208, a metal cup 209 and a yoke 214.

The contact arc extinguishing system and the electromagnetic system are installed in the shell 213 in a sealed mode;

the moving contact 204 is mounted on the central shaft 205, the central shaft 205 and the moving iron core 207 are mounted together, and when the coil 208 is energized, the moving iron core 207 is attracted by the static iron core 206 to move upward, so that the moving contact 204 is driven to move upward to be in contact with the

static contacts

202 and 203. The central shaft 205 is made of an insulating material, and realizes electrical isolation between the movable contact 204 and the movable iron core 207.

Arc chute chamber 215 has an insulating substrate 2151,

walls

2152 and 2153 perpendicular to substrate 2151, substrate 2151 being mounted together with

walls

2152 and 2153 or being formed integrally into a cup shape,

walls

2152 and 2153 having a circular arc configuration and being spaced in an end-to-end relationship, as shown in fig. 3a and 3 b. Wherein wall 2152 is located at a larger circumferential diameter than wall 2153. The base plate 2151 has a hole 2155 for allowing the terminal to pass therethrough, and a pair of oppositely disposed partition plates 2154 including guide spacers 2154a and guides 2154 b; the guiding and isolating part 2154a has a protruding rib 2156 on one side to guide the movement of the movable contact 204 and position the arc-extinguishing

chambers

210 and 211 on the other side, and the guiding and isolating part 2154a isolates the two arc-extinguishing chambers to prevent short circuit or gas channeling at this position. The guide 2154b further guides the gas in the sealed chamber, and the gap c between the wall 2152 is gradually reduced.

The

stationary contacts

202 and 203 and the movable contact 204 form two contact areas, the two contact areas are located at two ends of the movable contact 204, and the middle conductive areas are connected. Referring to fig. 2a, a reference rectangular coordinate system is established, and two transverse axes X and a longitudinal axis Y are established, which are perpendicular to each other, the two contact areas are located substantially on the transverse axis X, and the direction of separation of the movable contact 204 from the

stationary contacts

202 and 203 is parallel to the Z axis (not shown, which can be understood as being perpendicular to the plane of fig. 2a, or referred to as a dividing plane). The moving contact 204 is provided with an arc striking part 2043 which protrudes from the X-axis deflection to the Y-axis side and extends to the arc extinguishing chamber, and the arc striking part 2043 may have a certain bend back to the contact area, so that at the maximum breaking position, the moving contact 204 is equipotential with the grid sheet at the lowest part of the arc extinguishing chamber (such as the grid sheet at the lowest part in fig. 2 d), and the arc is lengthened as much as possible, so-called the bend back to the contact area deflects from the X-Y plane (also referred to as arc extinguishing plane) to the breaking direction of the contact system. It should be noted that, in the prior art, such as chinese patent publication No. CN2415444Y, the facing direction of two breaking points, the facing direction of two arc-extinguishing chambers, the arc-striking direction, and the breaking direction of the contact system can be substantially unified in a plane, similar to the X-Z plane or the breaking plane where the moving contact 204 moves in this application; in the application, the facing direction of the two breakpoints and the moving direction of the contact system are in an X-Z breaking plane. The protruding direction of the arc-striking part 2043 is the direction of X-axis to Y-axis deflection, the arc-striking

chambers

210 and 211 are arranged in the space deflected from the X-axis to the Y-axis, the projections of the arc-striking chambers are distributed in the arc-striking plane, and the arc-striking notches 2101c of the arc-striking chambers in the application deflect about 45 degrees (the included angle between the connecting line of the arc-striking notches and the origin of the rectangular coordinate system and the X-axis is about 45 degrees; the deflection angle of the arc-striking notches is preferably 30-60 degrees). The breaking plane or the arc extinguishing plane only explains the action principle of the contact arc extinguishing system and the arrangement mode of corresponding parts according to the projection relation, but does not consider that the corresponding parts only exist on the plane, for example, the breaking plane is also the plane generated by the electric arc, on the projection plane, the breaking moment of the movable and fixed contacts is elongated, and the electric arc is also elongated; the arc extinguishing plane is a projection plane for guiding the arc to move, and in the projection plane, the arc enters the arc extinguishing chamber and goes deep.

The magnetic field normalization means is located on the outer circumference of the wall 2153, and as in this application, the

permanent magnets

301, 302 are mounted on the outer circumference of the wall 2153 in a tile-like configuration, with the origin located on the X-axis extending in a deflected manner in the Y-axis direction (arc movement direction).

Fig. 2b is an elevational view of the overall structure disclosed in the present invention. Wherein the contactor 201 includes: the

stationary contacts

202 and 203, the movable contacts 204, the

arc extinguishing systems

210 and 211, the electromagnetic system 212, and the arc extinguishing chamber 215. The electromagnetic system 212 includes a central shaft 205, a stationary core 206, a movable core 207, a bobbin coil 208, a metal cup 209, and a yoke 214. The contact system comprises moving and static contacts (202, 203, 204) for connecting and disconnecting an external direct current load circuit; the electromagnetic system 212 drives the moving contact 204 through the moving iron core 207 and the middle shaft 205 to complete the contact switching action, and both ends of the moving contact 204 are respectively contacted with the static contacts (202, 203), which is called a bridge type contact system. The electromagnetic system 212 is equipped with a diaphragm made of a plastic material with high flame-retardant rating, gas-generating material may be added to enhance the blowing action if necessary, and in particular, the use of a plastic material containing hydrogen improves the thermal conductivity inside the arc, thus enabling the thermal energy of the arc to be easily diffused. The electromagnetic system 212 is completely surrounded by a metal cup 209. the metal cup 209 primarily acts as a magnetic yoke, with the large area metal outer surface assisting in arc cooling. The metal cup 209 is made of a magnetically conductive metal material, such as electrically pure iron, and is plated on the outer surface. The arc-extinguishing chamber (210, 211) can be made of cold-rolled steel plate, copper plate, Nomex section or ceramic

Fig. 2c is a side view of the overall structure disclosed in the present invention, and it can be seen that compared with the conventional solution, the structure maximally utilizes the left and right cavity spaces of the product, and skillfully arranges the arc-extinguishing

chambers

210 and 211. Further, according to the present invention, since the

permanent magnets

301 and 302 are mounted outside the arc extinguishing chamber 215 and physically separated from the inside of the arc extinguishing chamber, thereby preventing arc contamination, the arc extinguishing chamber 215 can also prevent deterioration of the magnetic characteristics of the

permanent magnets

301 and 302, and can maintain the function of rapidly and reliably extinguishing an arc for a long period of time.

Fig. 2d is a schematic diagram of an internal structure of the contact arc extinguishing system disclosed by the invention, the movable contact 204 adopts a special structure with an arc striking angle design, and the arc striking angle design is matched with the action of the arc tile-shaped permanent magnets 310 and 302, so that the electric arc can be prevented from being excessively burnt at the breaking position of the movable and stationary contacts, and the electric arc is induced to contact with the arc extinguishing chambers (210 and 211) along a desired direction through the action of a magnetic field, so that the electric arc can disappear, and the degradation speed of the movable and stationary contacts (202, 203 and 204) and the arc extinguishing chamber is greatly reduced.

Fig. 3a is a top view of the installation of the arc chute and arc extinguishing chamber disclosed in the present invention. High-temperature arcing gas generated by the moving contact and the static contact in the high-level breaking process enters the arc extinguishing chambers (210, 211), the electric arc is cut into a plurality of sections of short arcs through the grid pieces, so that the initial dielectric strength of an arc gap is improved, and meanwhile, the grid pieces (such as copper grid pieces, ferromagnetic grid pieces, ceramics and the like) have the functions of enhancing cooling and surface recombination. In addition, the arc is stretched by the magnetic driving force generated by the arc extinguishing chambers (210, 211) and the magnetic field generated by the permanent magnets (Fleming's rule), the arc with the extended length can be cooled by the gas atmosphere (air, nitrogen or hydrogen, etc.), and meanwhile, the arc burning gas is driven to flow and circulate in the gas storage space of the arc extinguishing cavity 215 by means of the pressure gradient of the arc extinguishing system, wherein the arc extinguishing chambers (210, 211) are horizontally arranged, and arc extinguishing grid pieces are arranged in parallel. The arc extinguish chamber cavity structure can be improved to be similar to a 'Taiji diagram' shaped cavity by the traditional rectangular cavity scheme, so that the capacity of the arc extinguish chamber is increased, and the internal circulation of high-temperature arcing gas on the upper layer of the contactor can be promoted.

Fig. 3b is a schematic structural diagram of the arc extinguishing chamber disclosed in the present invention. A guide groove structure is provided in the arc extinguishing chamber 215, and the arc is completely isolated from the outside.

Fig. 4a-4b are schematic diagrams of two movable contact bridge structures disclosed by the present invention, and the movable contact 204 adopts a special structure with an arc striking angle design, and can avoid the excessive burning of the arc at the breaking position of the movable contact and the fixed contact by matching the action of the arc tile-shaped permanent magnets 310 and 302.

Fig. 5a is a schematic structural diagram of an arc extinguish chamber 210 disclosed in the present invention, wherein the arc extinguish grid plate may be made of cold-rolled steel plate, copper plate, Nomex profile or ceramic, and the grid plate structure is adjusted according to the moving path of the moving contact, so as to keep the gap consistent, and the stationary contact may be designed in an equipotential manner, and at the same time, arc shield support members 2102 are provided at both sides of the grid plate for supporting and fixing. In a region where the current is large (for example, rated current), the magnetic flux passing through the U-shaped notches of the plurality of grid pieces magnetically drives the arc deep into the space formed by the U-shaped notches. The long arc is cut into short arcs by the arc extinguishing chamber 210, a voltage drop is generated, an arc voltage for maintaining the arc is increased, and if the arc voltage becomes higher than a power supply voltage, the arc is extinguished. And in the process of cutting the electric arc each time, the heat transfer efficiency of the grid sheet with large area is higher, which is beneficial to the rapid cooling of the electric arc.

As shown in fig. 5a-5c, the arc chute 2101 comprises a curved head portion 2101a, a body portion 2101b and an arc striking slot 2101c, and the arc striking plate 2103 comprises a curved head portion 2103a, a body portion 2103b, a coupling portion 2103 c; the arc chute 2101 is stacked on the support 2102 to form the

arc chutes

210 and 211, and the striking plate 2103 is located at the top of the arc chute. The head 2103a of the arc striking plate 2103 is longer than the head 2101a of the arc extinguishing grid plate 2101 so as to be close to the static contact, and the equal potential between the arc striking plate 2103 and the static contact is formed during breaking, so that the electric arc can be conveniently transferred to the arc striking plate 2103 from the static contact. The plane of the arc extinguishing grid 2101 and the arc striking plate 2103 in the bending direction is perpendicular to the plane of the moving direction of the movable contact 204. The coupling part 2103c has a structure adapted to the outer contour of the stationary contact (202, 203) to help the arc on the stationary contact to be uniformly transferred to the arc ignition piece 2103.

The opening direction of the arc striking slot 2101c of the arc chute 2101 faces the deflection direction of the arc striking portion 2043 of the movable contact 204. A curved head 2101a is located at one side of the arc striking slot 2101c in order to guide a curved circuit path.

The structure and the magnetic blowout arc ignition principle of the invention are further explained according to fig. 6 a. Similarly, an X-Y rectangular coordinate system is established, and the tile-shaped

permanent magnets

301 and 302 extend clockwise from the X axis to the Y axis to form an arc-shaped surrounding structure for the contact arc extinguishing system, and the extended cut-off position may be on the Y axis as shown in fig. 6a, or may be less than or more than the Y axis depending on the size and position of the

arc extinguishing chambers

210 and 211, so as to make the magnetic field cover the moving path of the arc. The S pole of the permanent magnet 301 near the arc extinguish chamber 210 faces the contact arc extinguish system, and the N pole faces away from the contact arc extinguish system; the N pole of the permanent magnet 302 near the arc chute 211 faces the contact arc quenching system and the S pole faces away from the contact arc quenching system. The magnetic field from the permanent magnet 302 to the permanent magnet 301 is formed, and due to the tile-shaped permanent magnet structure, magnetic lines of force are more concentrated in the contact arc extinguishing system area and have a magnetic field density concave towards the middle, so that the permanent magnet can act on more contact arc extinguishing systems in the smallest size as possible, and more magnetic lines of force act on an arc path. In this embodiment, the arrangement of the magnetically permeable arc chute plates on the magnetic field path enhances the effect of the magnetic field lines contracting inwardly.

As shown in fig. 2a, 2b, 4a and 6a, when the contactor is opened, the movable contact 204 moves downward to separate from the fixed contact, an arc is generated, the arc is elongated in a direction parallel to the Z axis, and since the arc striking portion 2043 extends in a deflecting manner in the contact area to the Y axis direction, when the movable contact 204 moves to the maximum breaking position, the arc is transferred to the lowermost arc chute 2101 by the arc striking portion 2043; on the other hand, the arc tab 2103 has a head 2103a which is oriented toward the stationary contact, so that the arc is transferred from the stationary contact to the head 2103 a. In order to help the arc transfer from the contact system to the arc extinguishing system, the invention adopts the arc striking mode of rotating air blow and rotating magnetic blow besides the arc striking device.

As shown in fig. 2a and 7a to 7c, an arc isolating plate 3041 is further provided, which is mounted on the driving shaft 205 and located at the middle position of the movable contact 204, and separates two contacts of the movable contact 204 into two spaces. So that the high-temperature gas generated between the moving contact and the static contact at the two sides of the contact bridge flows in the respective gas flow channels. The high temperature gases of the two contact areas are prevented from communicating directly at the movable contacts 204. The arc-isolating plate 3041 and the arc-isolating plate 2154 are structurally coupled to each other, and form a blocking structure for preventing the movement of air flow in the Z-axis direction, the Y-axis direction and one side direction of the X-axis direction with the moving contact 204 and the base plate 2151, and in addition, any pair of opposite rib plates 2156 on the two arc-isolating plates 2154 and the plane of the adjacent arc-isolating plate 3041 form a sealed structure. Taking the arc formed between the fixed contact 202 and the movable contact 204 as an example, the high-temperature gas can only move to the left side of the X axis, and due to the guidance of the arc-shaped wall 2153 of the arc extinguishing cavity 215 and the deflection of the arc movement, the high-temperature gas moves clockwise, passes through the arc extinguishing chamber and the longer gas path under the guidance of the guidance part 2154b, and blows the cooled gas to the area between the fixed contact 203 and the movable contact 204, which helps to form a circular gas blowing effect. Since the gap c between the guide 2154b and the wall 2152 is gradually reduced, an acceleration effect of the gas flow is created there, further promoting the arc and rotational movement of the gas flow.

In addition, referring to fig. 6a, explaining the principle of the rotating magnetic blow of the present invention, if it is specified that the fixed contact 202 is connected to the positive pole, and the fixed contact 203 is connected to the negative pole, then the current direction flows from the fixed contact 202 to the movable contact 204, and then from the movable contact 204 to the fixed contact 203, in fig. 6a, the arc direction between the fixed contact 202 and the movable contact 204 penetrates into the plane of the drawing, and the arc direction between the fixed contact 203 and the movable contact 204 penetrates out of the plane of the drawing. The permanent magnets (301, 302) are in arc tile-shaped sheet structures, and the raw materials adopt neodymium iron boron or ferrite. The installation positions are arranged to be opposite in oblique angles, such as 45 degrees in the example (the two permanent magnets are symmetrically arranged in the second and fourth quadrants of a virtual rectangular coordinate system which takes the central axis 205 as the origin and the connecting line of the two fixed contacts as the X axis; the center of the central axis 205 is taken as the origin; and the permanent magnets are properly extended according to the size of the arc extinguish chamber, and the permanent magnets can be properly extended from the second and fourth quadrants to the first and third quadrants respectively under the condition that the arc extinguish chamber is large). The magnetic lines of force 303 in the middle are located approximately in the middle of the permanent magnet near the contact area, the arc striking portion 2043 and the arc striking groove 2101c, as shown in the figure, the oblique 45-degree direction magnetic lines of force 303 formed by the arc extinguishing system thus arranged can pass through the center of the contact, so that a magnetic blowing force F is formed at an angle of 90 degrees to the magnetic lines of force at the position where the arc striking portion 2043 and the arc striking groove 2101c correspond, (in the electromagnetic system, the magnetic blowing force F is 90 degrees to the magnetic field, which is highlighted in this embodiment for the purpose of explaining that when in this position, the electromagnetic force F helps the arc to enter the arc extinguishing chamber through the arc striking groove 2101 c). The arc extinguishing chamber helps the arc to gradually move in the depth direction of the arc extinguishing chamber, after the arc completely enters the arc extinguishing chamber, the arc needs to move in the direction parallel to the X axis, at the moment, the middle magnetic line 303 still can only act in the direction of 45 degrees obliquely above the arc, at the moment, the magnetic resistance at the position of the arc extinguishing chamber is smaller, so that the magnetic line 303 at the edge side has the effect of shrinking towards the arc extinguishing chamber, the magnetic line deflects to pass through the arc extinguishing chamber and then reaches the permanent magnet at the other side, the path of the magnetic line is bent, and the bent magnetic line helps the movement direction of the arc to deflect to the direction parallel to the X axis, so that the space of the arc extinguishing chamber is fully utilized to cool the arc and extinguish the high-temperature gas. According to the structure, the arc blowing direction is on the diagonal line, so that the arc blowing space is larger, arc breaking is facilitated, the arc extinguishing capability is stronger, and the space utilization rate of a product is higher.

It should be noted that, in the above embodiment, the fixed contact 202 is connected to the positive electrode, and the fixed contact 203 is connected to the negative electrode, so the arc striking mode is arranged with the clockwise direction as the reference direction, and the arc moves into the arc extinguish chamber with the clockwise direction, which determines the direction of the magnetic field. If the fixed contact 202 is connected with the negative pole and the fixed contact 203 is connected with the positive pole, the arc striking direction needs to be arranged in a counterclockwise direction, and according to the principle of the invention, the arc striking of the movable contact 204, the positions of the

arc extinguishing chambers

210 and 211, the opening direction of the arc striking groove, the positions of the

permanent magnets

301 and 302, the arrangement of the polarity and the like are arranged in a counterclockwise direction as a reference direction, as shown in fig. 6 b.

While the invention has been described with respect to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Those skilled in the art can make various changes, modifications and equivalent arrangements, which are equivalent to the embodiments of the present invention, without departing from the spirit and scope of the present invention, and which may be made by utilizing the techniques disclosed above; meanwhile, any changes, modifications and variations of the above-described embodiments, which are equivalent to those of the technical spirit of the present invention, are within the scope of the technical solution of the present invention.

Claims

1. A direct current contactor arc extinguishing system comprises a contact system, an arc extinguishing system, an electromagnetic system and a shell; a contact system, an arc extinguishing system and an electromagnetic system are arranged in the shell; the contact system comprises a fixed contact and a movable contact; the electromagnetic system comprises a driving middle shaft, a static iron core, a movable iron core, a framework coil, a metal cup and a yoke iron; a contact system is arranged above the electromagnetic system, and an arc extinguishing system is arranged at the periphery of the contact system; the method is characterized in that: the arc extinguishing system comprises an arc extinguishing chamber, an arc striking device and an arc isolating device; the arc extinguish chamber is arranged on the outer periphery of a relative motion area between a moving contact and a fixed contact of the direct current contactor and between the two fixed contacts; the moving contact and the arc extinguish chamber are provided with arc striking devices; an arc isolating device is arranged in the shell.

2. The dc contactor arc extinguishing system according to claim 1, wherein: the arc striking device comprises an arc striking part arranged on the moving contact and an arc striking sheet arranged on the arc extinguishing chamber; the moving contact is provided with an arc striking part extending to the arc extinguishing chamber; and one end of the arc extinguish chamber close to the static contact is provided with an arc striking sheet extending towards the static contact.

3. The dc contactor arc extinguishing system according to claim 2, wherein: the arc striking part of the moving contact is a bending part which is bent and extended towards the arc extinguish chamber along the direction of generating an arc path by the plane of the moving contact.

4. The dc contactor arc extinguishing system according to claim 2, wherein: the arc extinguish chamber is provided with grid pieces which are arranged in parallel in a layered manner, and the grid pieces are provided with bent heads along the direction of an arc path; the grid piece is provided with an arc striking groove corresponding to the arc striking part of the moving contact; the arc extinguishing chamber top is equipped with the striking plate, and the striking plate is close to the one end of static contact and is also equipped with crooked head along the same direction of the crooked head of grid piece along the direction that produces the electric arc route, and the crooked head length of striking plate is greater than the crooked head length of grid piece.

5. The dc contactor arc extinguishing system according to claim 4, wherein: the arc isolating device comprises an arc extinguishing cavity and an arc isolating plate arranged on the moving contact driving middle shaft; the arc extinguishing cavity is cylindrical with the driving middle shaft as a central axis, and an arc extinguishing chamber and a contact system are arranged in the arc extinguishing cavity; one end of the cylindrical arc extinguishing cavity close to the moving contact is provided with an opening, and the other end of the cylindrical arc extinguishing cavity is provided with a substrate; the cylindrical arc extinguishing cavity is provided with a continuous cylindrical wall; two sections of arc-shaped partition plates which are symmetrically arranged relative to the center of the driving center shaft are arranged on the substrate and are perpendicular to the substrate; the moving contact top be equipped with the flash barrier of perpendicular to moving contact plane, the intermediate position at moving contact top portion is located to the flash barrier, separates two spaces with two contacts that the moving contact contacted with the static contact.

6. The dc contactor arc extinguishing system according to claim 5, wherein: the cylindrical wall of the cylindrical arc extinguishing cavity is formed by four right-angle fan-shaped arc surfaces with two diameters arranged at intervals, and the joint of the two right-angle fan-shaped arc surfaces with different diameters is arranged on the connecting line of the two static contacts.

7. The dc contactor arc extinguishing system according to claim 5, wherein: the base plate is provided with through holes penetrating through the two static contacts, and two sections of arc-shaped clapboards perpendicular to the base plate are symmetrically arranged between the through holes of the two static contacts and between the arc extinguish chamber and the moving contact relative to the center of the driving center shaft; one end of the arc-shaped partition board, which is far away from the bent head of the arc striking plate, is close to the fixed contact on one side, and the other end of the arc-shaped partition board is arranged on the outer side of the region, opposite to the fixed contact, of the bent head of the arc striking plate.

8. The dc contactor arc extinguishing system according to claim 7, wherein: the arc-shaped partition plate is provided with a guide part, and a gap formed between the guide part on one side of the arc-shaped partition plate close to the static contact and the cylindrical wall of the cylindrical arc extinguishing cavity is gradually reduced when the guide part is gradually close to the static contact.

9. The dc contactor arc extinguishing system according to claim 8, wherein: the two sections of arc-shaped partition plates are respectively provided with two corresponding rib plates which are perpendicular to the base plate and used for limiting the motion guidance of the moving contact, the rib plates arranged on the same section of arc-shaped partition plate are arranged on two sides which are equidistant to the driving center shaft, and the corresponding rib plates and the arc partition plate of the driving center shaft form a partition structure which partitions two contacts, which are in contact with the moving contact and the static contact, into two spaces.