A DC contactor arc extinguishing system

Abstract

The present invention relates to an arc extinguishing system for a DC contactor, and belongs to the technical field of DC contactors. The DC contactor includes a contact system, an arc extinguishing system, an electromagnetic system and a shell; the arc extinguishing system includes an arc extinguishing chamber, an arc striking device and an arc isolating device; the moving contact of the contact system and the arc extinguishing chamber are provided with an arc striking device; and the shell is provided with an arc isolating device. Under the premise of a certain product volume, the present invention improves the structure of the arc extinguishing chamber, adds arc striking devices and arc isolating device structures, and fully utilizes the limited internal space for arc extinguishing. In addition, the airway circulation and diffusion of high-temperature arcing gas in the contactor cavity are realized, the arc cooling effect is enhanced, the main cavity is avoided from being polluted, and the arc extinguishing ability is further improved. The high-temperature gas generated between the moving and static contacts on both sides of the contact bridge flows in their respective airflow channels. In the event of a short circuit fault, the risk of contact melting and welding is reduced, and the contact reliability is improved.

Description

Technical Field

[0001] The invention relates to an arc extinguishing system for a DC contactor, belonging to the technical field of DC contactors. Background Art

[0002] A DC contactor is a contactor used in a DC circuit, mainly used to control a DC circuit (main circuit, control circuit, excitation circuit, etc.). A DC contactor needs to frequently open and close large load currents, so it must have a strong arc extinguishing capability, a flexible contact system, and a reliable electromagnetic system.

[0003] In the field of new energy applications, for example, pure electric vehicles usually use high-voltage DC contactors to connect and disconnect the power battery system, and can disconnect the high-voltage battery system in the event of an accident. The electrical contacts will discharge and generate arcs during the process of connection and disconnection. The generation of arcs will delay the circuit breaking. Higher arc energy may even burn the electrical contacts, causing them to melt and weld. In addition, since the current DC contactors are sealed, in severe cases, they may cause the switch electrical appliances to catch fire and explode.

[0004] In the prior art, in order to make the DC contactor product small in size and high in operating load, high-voltage DC contactors usually use sealed gas-filled external magnetic fields to stretch the metal phase arc laterally, and the arc is quickly cooled, compounded and deionized in the arc extinguishing medium. Under normal circumstances, the above technical means have limited arc extinguishing space, long arc burning time, low arc extinguishing capacity, and it is difficult to improve the electrical life indicators. In addition, the metal particles and carbonized impurities generated during the arc extinguishing process accumulate inside the arc extinguishing cavity, polluting the cavity, which easily leads to a decrease in insulation capacity after a certain degree of electrical life. For example: At present, manufacturers such as Tyco, Panasonic, and LS in the market all use magnetic blowout arc extinguishing technology. Under higher-level breaking conditions, their life capacity drops sharply and may even explode.

[0005] The internal structure of the common high-voltage DC contactor is shown in the following figure. Figure 1a , 1b As shown. In the existing patent literature, Chinese invention patent announcements CN102074387A and CN104412353A also disclose two typical structural arrangements of high-voltage DC contactors. The disadvantage of this design is that the contact arc extinguishing system does not fully utilize the upper cavity volume of the contactor ( Figure 1b The side view shows that the cavities on both sides of the moving contact bridge are isolated from the contact arc extinguishing system, and the cavity is not effectively utilized. The arc extinguishing capacity is limited. At the same time, it is difficult to continue to improve the arc extinguishing capacity and shorten the arc burning time by relying solely on the technical means of permanent magnet magnetic blowing arc extinguishing under gas atmosphere conditions. The arc extinguishing chamber adopts a square closed cavity, and the arc extinguishing channel is narrow and long. The high-temperature arc burning gas cannot flow and circulate. Under higher-level breaking, it is easy for the arc burning gas to be unable to escape and cool quickly, and the excessive pressure in the inner cavity causes the product to explode.

[0006] In the existing new energy application field, the power battery system is generally 400VDC, which may be greatly increased in the future. Therefore, the high-voltage DC contactor needs a stronger arc extinguishing ability, which can safely open and close relatively large currents and avoid damage to the contacts in the contactor caused by welding and excessive arcs. Therefore, this technical field urgently needs to use arc extinguishing devices in DC contactors to achieve efficient and reliable arc extinguishing effects. Summary of the invention

[0007] The purpose of the present invention is to solve the technical problem of achieving efficient and reliable arc extinguishing in a DC contactor.

[0008] In order to achieve the purpose of solving the above-mentioned problems, the technical solution adopted by the present invention is to provide a DC contactor arc extinguishing system, the DC contactor includes a contact system, an arc extinguishing system, an electromagnetic system and a shell; the shell is provided with a contact system, an arc extinguishing system and an electromagnetic system; the contact system includes a static contact and a moving contact; the electromagnetic system includes a driving center shaft, a static iron core, a moving iron core, a skeleton coil, a metal cup and a yoke; a contact system is provided above the electromagnetic system, and an arc extinguishing system is provided around the contact system; the arc extinguishing system includes an arc extinguishing chamber, an arc striking device and an arc isolating device; the arc extinguishing chamber is provided on the outer periphery of the relative motion area between the moving contact and the static contact of the DC contactor, between the two static contacts; the moving contact and the arc extinguishing chamber are provided with an arc striking device; the shell is provided with an arc isolating device.

[0009] Preferably, the arc striking device comprises an arc striking portion provided on the moving contact and an arc striking piece provided on the arc extinguishing chamber; the moving contact is provided with an arc striking portion extending toward the arc extinguishing chamber; the arc extinguishing chamber is provided with an arc striking piece extending toward the static contact at one end close to the static contact.

[0010] Preferably, the arc striking portion of the moving contact is configured as a bent portion extending from a plane of the moving contact along a direction of generating an arc path toward the arc extinguishing chamber.

[0011] Preferably, the arc extinguishing chamber is provided with grid plates arranged in parallel in layers, and the grid plates are provided with bent heads along the direction of the arc path; the grid plates are provided with arc-striking grooves corresponding to the arc-striking portions of the moving contacts; an arc-striking plate is provided at the top of the arc extinguishing chamber, and an end of the arc-striking plate close to the static contact is also provided with a bent head along the direction of the arc path and in the same direction as the bent head of the grid plates, and the length of the bent head of the arc-striking plate is greater than the length of the bent head of the grid plates.

[0012] Preferably, the arc-isolating device includes an arc-extinguishing cavity and an arc-isolating plate provided on the driving axis of the moving contact; the arc-extinguishing cavity is set to be cylindrical with the driving axis as the central axis, and an arc-extinguishing chamber and a contact system are provided in the arc-extinguishing cavity; the cylindrical arc-extinguishing cavity is open at one end close to the moving contact, and a base plate is provided at the other end; the cylindrical arc-extinguishing cavity is provided with a continuous cylindrical wall; two sections of arc-shaped partitions are arranged symmetrically relative to the center of the driving axis and are perpendicular to the base plate on the base plate; the top of the moving contact is provided with an arc-isolating plate perpendicular to the plane of the moving contact, and the arc-isolating plate is provided in the middle position of the top end of the moving contact to separate the two contact points where the moving contact and the static contact are in contact in two spaces.

[0013] Preferably, the cylindrical wall of the cylindrical arc-extinguishing cavity is composed of four right-angled sector-shaped arc surfaces of two different diameters arranged at intervals, and the connection point of the two sections of right-angled sector-shaped arc surfaces of different diameters is arranged on the two static contact connection lines.

[0014] Preferably, the substrate is provided with a through hole for passing two static contacts, and two sections of arc-shaped partitions perpendicular to the substrate are symmetrically arranged between the through holes of the two static contacts and between the arc extinguishing chamber and the moving contact relative to the center of the driving axis; one end of the arc-shaped partition is away from the bent head of the arc-striking piece and close to the static contact on one side, and the other end of the arc-shaped partition is arranged on the outside of the relative area between the bent head of the arc-striking piece and the static contact on the other side.

[0015] Preferably, the arc partition is provided with a guide portion, and when the guide portion on the side of the arc partition close to the static contact gradually approaches the static contact, the gap formed between the guide portion and the cylindrical wall of the cylindrical arc extinguishing cavity gradually decreases.

[0016] Preferably, the two arc-shaped partitions are each provided with two corresponding ribs perpendicular to the substrate for limiting the movement guide of the moving contact. The ribs on the same arc-shaped partition are arranged on both sides equidistant from the driving center axis. The corresponding ribs and the arc-isolating plates of the driving center axis form a partition structure that separates the two contact points of the moving contact and the static contact into two spaces.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The technical solution of the present invention solves the problems in the prior art that the arc extinguishing capacity is limited, the arc extinguishing chamber adopts a square closed cavity, the arc extinguishing channel is narrow and long, the high-temperature arc-burning gas cannot flow and circulate, and the arc-burning gas is prone to be unable to escape and cool quickly under higher levels of disconnection, and the pressure in the inner cavity is too large to cause the product to explode. Under the premise of a certain product volume, the arc extinguishing chamber structure is improved, the arc striking device and the arc isolating device structure are added, and the limited internal space is fully utilized to extinguish the arc. In the limited cavity space, the arc extinguishing capacity is improved. In addition, the airway circulation and diffusion of the high-temperature arc-burning gas in the contactor cavity are realized, the arc cooling effect is enhanced, the main cavity is avoided from being polluted, and the arc extinguishing capacity is further improved. The high-temperature gas generated between the moving and static contacts on both sides of the contact bridge flows in their respective airflow channels. In the event of a short circuit fault, the risk of contact melting and welding is reduced, and the contact reliability is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1a , 1b It is a typical structure of existing high-voltage DC contactors;

[0020] Figure 2a It is a top view of the overall structure of the arc extinguishing chamber cavity of the present invention;

[0021] Figure 2b It is a front view of the overall structure of the present invention;

[0022] Figure 2c It is a side view of the overall structure of the present invention;

[0023] Figure 2d It is a schematic diagram of the internal structure of the contact arc extinguishing system of the present invention;

[0024] Figure 3a This is a top view of the installation of the arc extinguishing chamber and the arc extinguishing cavity of the present invention;

[0025] Figure 3b It is a structural schematic diagram of the arc extinguishing cavity of the present invention;

[0026] Figure 4a It is a schematic diagram of the structure of the movable contact bridge of the present invention;

[0027] Figure 4b is a three-dimensional diagram of the movable contact structure of the present invention;

[0028] Figure 5a It is a schematic diagram of the arc extinguishing chamber structure of the present invention;

[0029] Figure 5b It is a schematic diagram of the arc extinguishing grid of the arc extinguishing chamber of the present invention;

[0030] Figure 5c It is a schematic diagram of an arc-starting piece of an arc-extinguishing chamber of the present invention;

[0031] Figure 6aIt is an embodiment of the arrangement of the permanent magnet and the arc extinguishing chamber of the present invention;

[0032] Figure 6b It is another embodiment of the arrangement of the permanent magnet and the arc extinguishing chamber of the present invention;

[0033] Figure 7a , 7b, 7c are schematic diagrams of the arc isolation plate structure of the high voltage DC contactor of the present invention. DETAILED DESCRIPTION

[0034] In order to make the present invention more clearly understood, a preferred embodiment is described in detail with reference to the accompanying drawings as follows:

[0035] The present invention provides an arc extinguishing system for a DC contactor. The DC contactor comprises a contact system, an arc extinguishing system, an electromagnetic system and a shell 213; the shell 213 is provided with the contact system, the arc extinguishing system and the electromagnetic system; the contact system comprises static contacts 202, 203 and a moving contact 204; the electromagnetic system comprises a driving central axis 205, a static iron core 206, a moving iron core 207, a skeleton coil 208, a metal cup 209 and a yoke 214; the contact system is arranged above the electromagnetic system, and the arc extinguishing system is arranged around the contact system; the arc extinguishing system comprises arc extinguishing chambers 210, 211, an arc striking device and an arc isolating device; the arc extinguishing chambers 210, 211 are arranged between two static contacts on the outer periphery of the relative motion area between the moving contact 204 and the static contacts 202, 203 of the DC contactor; the moving contact and the arc extinguishing chamber are provided with an arc striking device; and the shell is provided with an arc isolating device. The arc striking device comprises an arc striking portion 2043 provided on the moving contact 204 and an arc striking piece 2103 provided on the arc extinguishing chamber; the moving contact is provided with an arc striking portion 2043 extending toward the arc extinguishing chamber; the arc striking piece 2103 extending toward the static contact is provided at one end of the arc extinguishing chamber close to the static contact. The arc striking portion 2043 of the moving contact is set as a bent portion extending from the plane of the moving contact toward the arc extinguishing chamber along the direction of the arc path. The arc extinguishing chamber is provided with grid pieces 2101 arranged in layers and parallel, and the grid pieces are provided with bent heads 2101a along the direction of the arc path; the grid pieces are provided with arc striking grooves 2101c corresponding to the arc striking portion 2043 of the moving contact; the arc striking piece 2103 is provided at the top of the arc extinguishing chamber, and the end of the arc striking piece close to the static contact is also provided with a bent head 2103a in the same direction as the bent head of the grid piece along the direction of the arc path, and the length of the bent head 2103a of the arc striking piece is greater than the length of the bent head 2101a of the grid piece. The arc-isolating device comprises an arc-extinguishing cavity 215 and an arc-isolating plate 3041 provided on the driving axis of the moving contact; the arc-extinguishing cavity 215 is set to be cylindrical with the driving axis as the central axis, and an arc-extinguishing chamber and a contact system are provided in the arc-extinguishing cavity; the cylindrical arc-extinguishing cavity 215 is open at one end close to the moving contact, and a base plate 2151 is provided at the other end; the cylindrical arc-extinguishing cavity is provided with continuous cylindrical walls 2153 and 2152; two sections of arc-shaped partitions 2154 are arranged symmetrically relative to the center of the driving axis and are perpendicular to the base plate; an arc-isolating plate 3041 perpendicular to the plane of the moving contact is provided at the top of the moving contact, and the arc-isolating plate 3041 is provided in the middle position of the top end of the moving contact to separate the two contact points of the moving contact and the static contact in two spaces. The cylindrical wall of the cylindrical arc extinguishing cavity is composed of four right-angled sector-shaped arc surfaces of two different diameters arranged at intervals, and the connection between the two right-angled sector-shaped arc surfaces 2153 and 2152 of different diameters is arranged on the two static contact connection lines.The substrate is provided with through holes 2155 for penetrating two stationary contacts, and two arc-shaped partitions 2154 perpendicular to the substrate are symmetrically provided between the through holes of the two stationary contacts and between the arc extinguishing chamber and the moving contact relative to the center of the driving axis; one end of the arc-shaped partition 2154 away from the curved head 2103a of the arc-striking piece is close to the stationary contact on one side, and the other end of the arc-shaped partition 2154 is arranged outside the area where the curved head 2103 of the arc-striking piece is opposite to the stationary contact on the other side. The arc-shaped partition 2154 is provided with a guide portion, and the gap formed between the guide portion on the side of the arc-shaped partition close to the stationary contact and the cylindrical wall of the cylindrical arc extinguishing cavity 215 gradually decreases as it gradually approaches the stationary contact. The two arc-shaped partition plates 2154 are each provided with two corresponding rib plates 2156 perpendicular to the base plate for limiting the movement of the moving contact. The rib plates 2156 on the same arc-shaped partition plate are arranged on both sides equidistant from the driving center axis. The corresponding rib plates 2156 and the arc-isolating plates 3041 of the driving center axis form a partition structure that separates the two contact points of the moving contact and the static contact into two spaces.

[0036] It can be seen from gas movement and heat conduction that high-temperature and high-pressure gas always moves towards a low-temperature and low-pressure environment. In this way, the high-temperature and high-pressure gas generated by the arc moves toward the outlet of the arc extinguishing chamber, which is conducive to the gas blowing and rapid movement of the arc for cooling. In the contactor, it is very important for the arc to move forward quickly and diffuse in the arc extinguishing chamber, which helps to lengthen the arc and cool the arc. This is especially true in contactors for DC applications, which do not have the process of voltage and current crossing zero. Therefore, lengthening the arc and rapidly cooling the arc have become the most important means of arc extinguishing.

[0037] Based on the existing magnetic blow-out arc extinguishing and the fixed product volume, the present invention adopts arc-shaped permanent magnets and arranges grid arc extinguishing chambers in a limited space. The arc is cut into multiple short arcs by the arc extinguishing chamber grid, thereby improving the initial dielectric strength of the arc gap. At the same time, the grid (such as copper grid, ferromagnetic grid, ceramic, etc.) has enhanced cooling and surface recombination effects. For large current interruption (such as rated current), the magnetic driving force generated by the grid arc extinguishing chamber and the magnetic field (Fleming's law) generated by the permanent magnet stretch the arc. The arc with extended length can be cooled by the gas atmosphere (air, nitrogen or hydrogen, etc.), and the pressure gradient of the arc extinguishing system is used to drive the arc burning gas to be discharged to the pre-set flow channel cavity on both sides. Finally, the circulation of the arc burning gas is used to further strengthen the stretching and cooling of the arc at the other break, and the entire circulation process is similar to the form of a "Tai Chi diagram". This scheme adopts a method similar to the inner cavity gas outlet to greatly reduce the pressure coefficient of the arc extinguishing chamber, reduce the risk of product explosion, and enable the high-temperature arc burning gas to flow and circulate effectively for cooling. This not only provides a larger arc extinguishing space, shorter arc burning time, and higher arc voltage, but also the flow of arc burning gas gathers metal particles and carbonized impurities at the rear of the arc extinguishing chamber, ensuring the cleanliness and insulation resistance of the main chamber. In addition, the arc extinguishing chamber shell can also prevent the magnetic properties of the permanent magnet from deteriorating, and can maintain the function of quickly and reliably extinguishing the arc for a long time.

[0038] Example:

[0039] Figure 2aIt is a top view of the overall structure of the arc extinguishing chamber cavity disclosed in the present invention. The arc extinguishing cavity 215 is equipped with static contacts 202 and 203, a moving contact 204, and grid arc extinguishing chambers 210 and 211. In addition, permanent magnets 301 and 302 are respectively fixed on the outside of the arc extinguishing cavity 215. The contact system includes moving and static contacts (202, 203, 204) for connecting and disconnecting the external DC load circuit; the two ends of the moving contact 204 are respectively in contact with the static contacts (202, 203), which is called a bridge contact system; the arc extinguishing chambers 210 and 211 are used to complete the arc extinguishing action; the arc extinguishing cavity 215 is used to accommodate the contact system and the arc extinguishing chambers (210, 211). The high-temperature arc (216, 217) generated by the moving and static contacts during the disconnection process enters the arc extinguishing chambers 210 and 211 through the cavity 215, and the arc is cut into multiple short arcs by the grid, thereby improving the initial dielectric strength of the arc gap. At the same time, the grid (such as copper grid, ferromagnetic grid, ceramic, etc.) has the effect of strengthening cooling and surface recombination. In addition, the magnetic driving force generated by the arc extinguishing chamber (210, 211) and the magnetic field (Fleming's law) generated by the permanent magnet stretch the arc (216, 217), and the arc (216, 217) with an extended length can be cooled by the gas atmosphere (air, nitrogen or hydrogen, etc.). At the same time, the pressure gradient of the arc extinguishing system drives the arc (216, 217) to be discharged to the arc-shaped flow channel cavity pre-set in the arc extinguishing cavity 215 on both sides. Finally, the circulation of the arc burning gas is used to further strengthen the stretching and cooling of the arc at the other break. The circulation of the entire arc (216, 217) is similar to the form of a "Tai Chi diagram". In addition, the flow of arcing gas gathers metal particles and carbonized impurities at the rear of the arc extinguishing chamber, ensuring the cleanliness and insulation resistance of the main cavity.

[0040] The DC contactor includes a contact arc extinguishing system, an electromagnetic system, and a housing;

[0041] The contact arc extinguishing system includes static contacts 202, 203, a moving contact 204, an arc extinguishing cavity 215, arc extinguishing chambers 210, 211, and a magnetic field regulating device;

[0042] The electromagnetic system includes a central axis 205 , a static iron core 206 , a moving iron core 207 , a skeleton coil 208 , a metal cup 209 and a yoke 214 .

[0043] The contact arc extinguishing system and the electromagnetic system are installed in the housing 213 in a sealed form;

[0044] The moving contact 204 is mounted on the central axis 205, and the central axis 205 is mounted together with the moving iron core 207. When the skeleton coil 208 is energized, the moving iron core 207 is attracted by the static iron core 206 and moves upward, thereby driving the moving contact 204 to move upward and contact the static contacts 202 and 203. The central axis 205 is made of insulating material to achieve electrical isolation between the moving contact 204 and the moving iron core 207.

[0045] The arc extinguishing cavity 215 has an insulating substrate 2151, walls 2152 and 2153 perpendicular to the substrate 2151, the substrate 2151 and the walls 2152 and 2153 are installed together or integrally formed into a cup shape, and the walls 2152 and 2153 have an arc-shaped structure and are arranged at intervals in an end-to-end manner, as shown in the attached Figure 3a , 3b . The circumferential diameter of the wall 2152 is greater than the circumferential diameter of the wall 2153. The substrate 2151 has a hole 2155 that allows the terminal to pass through, and also has a pair of oppositely arranged partitions 2154, which include a guide isolation portion 2154a and a guide portion 2154b; the guide isolation portion 2154a has a protruding rib plate 2156 on one side to guide the movement of the moving contact 204, and the other side positions the arc extinguishing chambers 210 and 211. At the same time, the guide isolation portion 2154a isolates the two arc extinguishing chambers to prevent short circuits or gas crossflow at this position. The guide portion 2154b further guides the gas in the sealed cavity, and the gap c with the wall 2152 gradually decreases.

[0046] The stationary contacts 202, 203 and the moving contact 204 form two contact areas, which are located at both ends of the moving contact 204 and are connected by the conductive area in the middle. Figure 2a , establish a reference rectangular coordinate system, establish two mutually perpendicular horizontal axes X and vertical axes Y, the two contact areas are roughly located on the horizontal axis X, and the direction in which the moving contact 204 separates from the static contacts 202 and 203 is parallel to the Z axis (not shown, it can be understood as perpendicular to Figure 2a The moving contact 204 is provided with an arc-starting portion 2043 protruding from the X-axis to the Y-axis and extending toward the arc-extinguishing chamber. The arc-starting portion 2043 may be bent to a certain extent away from the contact area so that the moving contact 204 and the grid at the bottom of the arc-extinguishing chamber (such as Figure 2dThe bottom grid) is at the same potential to lengthen the arc as much as possible. The so-called bending of the back contact area refers to the deflection from the XY plane (also called the arc extinguishing plane) to the disconnection direction of the contact system. It should be pointed out that in the prior art, such as the Chinese invention patent announcement No. CN2415444Y, the facing direction of the two breakpoints, the facing direction of the two arc extinguishing chambers, the arc striking direction, and the disconnection direction of the contact system can be roughly unified in one plane, similar to the XZ plane in this application or the disconnection plane where the moving contact 204 moves; in this application, the facing direction of the two breakpoints and the movement direction of the contact system are in the XZ disconnection plane. The protruding direction of the arc striking portion 2043 is in the direction of deflection from the X-axis to the Y-axis. The arc extinguishing chambers 210 and 211 are arranged in the space deflected from the X-axis to the Y-axis, and their projections are distributed in the arc striking plane. In the present application, the arc striking slot 2101c of the arc extinguishing chamber is deflected by about 45 degrees (the angle between the arc striking slot and the origin of the rectangular coordinate system and the X-axis is about 45 degrees; the deflection angle of the arc striking slot is preferably between 30-60). The above-mentioned breaking plane or arc extinguishing plane is only used to explain the working principle of the contact arc extinguishing system and the arrangement of the corresponding components based on the projection relationship, rather than considering that the corresponding components only exist on this plane. For example, the breaking plane is also the plane where the arc is generated. On this projection plane, the breaking torque of the moving and static contacts is elongated, and the arc is also elongated; and the arc extinguishing plane is the projection plane for guiding the arc movement. In this projection plane, the arc enters the arc extinguishing chamber and continues to go deeper.

[0047] The magnetic field regulating device is located on the outer circumference of the wall 2153. As in the present application, the permanent magnets 301, 302 are installed on the outer circumference of the wall 2153 in a tile-shaped structure, with the starting point located on the X-axis and extending in a deflected manner toward the Y-axis direction (arc movement direction).

[0048] Figure 2bIt is a front view of the overall structure disclosed in the present invention. The contactor 201 includes: static contacts 202 and 203, a moving contact 204, arc extinguishing chambers 210 and 211, an electromagnetic system 212 and an arc extinguishing cavity 215. The electromagnetic system 212 includes a central axis 205, a static iron core 206, a moving iron core 207, a skeleton coil 208, a metal cup 209 and a yoke 214. The contact system includes moving and static contacts (202, 203, 204) for connecting and disconnecting an external DC load circuit; the electromagnetic system 212 drives the moving contact 204 through the moving iron core 207 and the central axis 205 to complete the contact switching action, and the two ends of the moving contact 204 are respectively in contact with the static contacts (202, 203), which is called a bridge contact system. The electromagnetic system 212 is equipped with a partition on the top. The partition is made of a plastic material with a high flame retardant grade. If necessary, a gas-generating material can be added to enhance the gas blowing effect. In particular, by using a plastic material containing hydrogen, the thermal conductivity inside the arc is improved, so that the heat energy of the arc can be easily diffused. The outside of the electromagnetic system 212 is completely covered by a metal cup 209. The metal cup 209 mainly serves as a magnetic yoke, and its large metal outer surface assists in arc cooling. The metal cup 209 is made of a magnetic conductive metal material, such as electrical pure iron, and the outer surface is electroplated. The arc extinguishing chamber (210, 211) can be made of cold-rolled steel plate, copper plate, Nomex profile or ceramic, etc.

[0049] Figure 2c It is a side view of the overall structure disclosed by the present invention. It can be seen that compared with the traditional solution, this structure makes the most of the left and right cavity spaces of the product and cleverly arranges the arc extinguishing chambers 210 and 211. In addition, according to the present invention, the permanent magnets 301 and 302 are assembled outside the arc extinguishing cavity 215 and are physically isolated from the inside of the arc extinguishing chamber to prevent arc contamination. Therefore, the arc extinguishing cavity 215 can also prevent the magnetic properties of the permanent magnets 301 and 302 from deteriorating, and can maintain the function of quickly and reliably extinguishing the arc for a long time.

[0050] Figure 2d It is a schematic diagram of the internal structure of the contact arc extinguishing system disclosed in the present invention. The moving contact 204 adopts a special structure with an arc-strike angle design, and cooperates with the arc-shaped tile-shaped permanent magnets 301 and 302 to avoid excessive burning of the arc at the breaking point of the moving and static contacts, and induces the arc to contact the arc extinguishing chamber (210, 211) along the desired direction through the action of the magnetic field, thereby making the arc extinguish, greatly slowing down the degradation rate of the moving and static contacts (202, 203, 204) and the arc extinguishing cavity.

[0051] Figure 3aIt is a top view of the installation of the arc extinguishing chamber and the arc extinguishing cavity disclosed in the present invention. The high-temperature arc-burning gas generated by the moving and static contacts during the high-level disconnection process enters the arc extinguishing chamber (210, 211), and the arc is cut into multiple short arcs through the grid, thereby improving the initial dielectric strength of the arc gap. At the same time, the grid (such as copper grid, ferromagnetic grid, ceramic, etc.) has enhanced cooling and surface recombination effects. In addition, the magnetic driving force generated by the arc extinguishing chamber (210, 211) and the magnetic field generated by the permanent magnet (Fleming's law) stretch the arc, and the arc with an extended length can be cooled by the gas atmosphere (air, nitrogen or hydrogen, etc.). At the same time, the pressure gradient of the arc extinguishing system is used to drive the arc-burning gas to flow and circulate in the gas storage space of the arc extinguishing cavity 215. Here, the arc extinguishing chamber (210, 211) is arranged horizontally, and the arc extinguishing grids are arranged in parallel. The arc extinguishing chamber cavity structure can be improved from the traditional rectangular cavity scheme to a cavity similar to the "Tai Chi diagram", which not only increases the capacity of the arc extinguishing chamber, but also promotes the internal circulation of high-temperature arcing gas in the upper layer of the contactor.

[0052] Figure 3b 2 is a schematic diagram of the structure of the arc extinguishing cavity disclosed in the present invention. A guide groove structure is provided in the arc extinguishing cavity 215, and the arc is completely isolated from the outside.

[0053] Figure 4a-4b It is a schematic diagram of two types of moving contact bridge structures disclosed in the present invention. The moving contact 204 adopts a special structure with an arc-starting angle design, which, together with the arc-shaped tile-shaped permanent magnets 301 and 302, can avoid excessive burning of the arc at the breaking point of the moving and static contacts.

[0054] Figure 5a It is a schematic diagram of the structure of the arc extinguishing chamber 210 disclosed in the present invention, wherein the material of the arc extinguishing grid can be cold-rolled steel plate, copper plate, Nomex profile or ceramic, etc., and the grid structure is adjusted according to the moving path of the moving contact to keep the gap consistent, and the static contact can be designed with equipotential, and at the same time, there are arc isolation plate supports 2102 on both sides of the grid to support and fix. In the area where the current is large (such as rated current), the magnetic flux passing through the U-shaped cuts of multiple grids magnetically drives the arc to the depth of the space formed by the multiple U-shaped cuts. The long arc is cut into a short arc by the arc extinguishing chamber 210, generating a voltage drop, which is used to maintain the arc voltage rising. If the arc voltage becomes a voltage higher than the power supply voltage, the arc is extinguished. In addition, during each arc cutting process, the heat transfer efficiency of the large-area grid is higher, which helps the arc to cool quickly.

[0055] like Figure 5a-5cThe arc extinguishing grid 2101 includes a curved head 2101a, a main body 2101b and an arc striking groove 2101c, and the arc striking piece 2103 includes a curved head 2103a, a main body 2103b and a coupling part 2103c; multiple arc extinguishing grids 2101 are stacked and installed on a support 2102 to form arc extinguishing chambers 210 and 211, and the arc striking piece 2103 is located at the top of the arc extinguishing chamber. The head 2103a of the arc striking piece 2103 is longer than the head 2101a of the arc extinguishing grid 2101 to be close to the static contact, so that the arc striking piece 2103 and the static contact are equal in potential when disconnected, which facilitates the transfer of the arc from the static contact to the arc striking piece 2103. The plane where the arc extinguishing grid 2101 and the arc striking piece 2103 are bent is perpendicular to the plane where the moving contact 204 is moving. The coupling portion 2103c has a structure adapted to the outer contour of the stationary contacts (202, 203) to help the arc on the stationary contacts to be evenly transferred to the arc-starting piece 2103.

[0056] The opening direction of the arc striking groove 2101c of the arc extinguishing grid 2101 faces the deflection direction of the arc striking portion 2043 of the moving contact 204. The curved head 2101a is located at one side of the arc striking groove 2101c so as to guide the curved circuit path.

[0057] according to Figure 6a The structure and magnetic arc blowing principle of the present invention are further explained. Similarly, an XY rectangular coordinate system is established. 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. The end position of the extension can be as follows: Figure 6a On the Y axis in the figure, the cut-off position can be extended less than or more than the Y axis according to 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 extinguishing chamber 210 faces the contact arc extinguishing system, and the N pole faces away from the contact arc extinguishing system; the N pole of the permanent magnet 302 near the arc extinguishing chamber 211 faces the contact arc extinguishing system, and the S pole faces away from the contact arc extinguishing system. In this way, a magnetic field is formed from the permanent magnet 302 to the permanent magnet 301. Due to the tile-shaped permanent magnet structure, the magnetic lines of force are more concentrated in the area of ​​the contact arc extinguishing system, with a magnetic field density concave toward the middle, and the permanent magnet can also act on more contact arc extinguishing systems with the smallest possible size, so that more magnetic lines of force act on the arc path. In this embodiment, the arc extinguishing grid with magnetic conductivity is arranged on the magnetic field path to enhance the effect of the magnetic lines of force shrinking inward.

[0058] like Figure 2a , 2b, 4a and 6a, when the contactor is disconnected, the moving contact 204 moves downward away from the stationary contact, generating an arc, which is elongated in the direction parallel to the Z axis. Since the arc-starting portion 2043 deflects and extends in the Y axis direction in the contact area, when the moving contact 204 moves to the maximum disconnection position, the arc on the moving contact 204 is transferred from the arc-starting portion 2043 to the lowest arc-extinguishing grid 2101; on the other hand, the arc-starting plate 2103 has a head 2103a that is completely facing the stationary contact, so the arc will be transferred from the stationary contact to the head 2103a. In this way, the arc is completely transferred from the contact system to the arc-extinguishing chamber. In order to help the arc transfer from the contact system to the arc-extinguishing system, in addition to the arc-starting device, the present invention also adopts the arc-starting method of rotating air blowing and rotating magnetic blowing.

[0059] like Figure 2a , 7a 7c, an arc isolation plate 3041 is also provided, which is installed on the driving center shaft 205 and is located in the middle position of the moving contact 204, separating the two contact points of the moving contact 204 into two spaces. The high-temperature gas generated between the moving and static contacts on both sides of the contact bridge flows in their respective airflow channels. The high-temperature gas in the two contact areas is prevented from being directly connected at the moving contact 204. The arc isolation plate 3041 and the arc-shaped partition plate 2154 are coupled to each other in structure, and a blocking structure is formed in the Z-axis direction, the Y-axis direction, and one side direction of the X-axis to prevent the movement of airflow by forming a blocking structure with the moving contact 204 and the substrate 2151. In addition, any pair of opposite rib plates 2156 on the two arc-shaped partition plates 2154 and the plane of the adjacent arc isolation plate 3041 form a sealed structure. Taking the arc formed between the static contact 202 and the moving contact 204 as an example, the high-temperature gas can only move to the left side of the X-axis. 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. Through the guiding effect of the guide portion 2154b, and through the arc-extinguishing chamber and the longer gas path, the cooled gas blows to the area between the static contact 203 and the moving contact 204, helping to form a cyclic gas blowing effect. Since the gap c between the guide portion 2154b and the wall 2152 is gradually reduced, the airflow acceleration effect is formed here, further promoting the rotational movement of the arc and the airflow.

[0060] In addition, according to the attached Figure 6a , explaining the principle of the rotary magnetic blowing of the present invention, if it is stipulated that the static contact 202 is connected to the positive pole and the static contact 203 is connected to the negative pole, then the current direction is from the static contact 202 to the moving contact 204, and then from the moving contact 204 to the static contact 203. Figure 6aIn the figure, the arc direction between the static contact 202 and the moving contact 204 is to penetrate into the plane of the drawing, while the arc direction between the static contact 203 and the moving contact 204 is to penetrate out of the plane of the drawing. The permanent magnets (301, 302) are arc-shaped thin-sheet structures, and the raw materials are neodymium iron boron or ferrite. The installation position is set to be opposite at an oblique angle, such as 45 degrees in this example (the two permanent magnets are symmetrically arranged in the second and fourth quadrants of the virtual rectangular coordinate system with the central axis 205 as the origin and the connecting line of the two static contacts as the X axis; the center of the central axis 205 is the origin; the permanent magnets are appropriately extended according to the size of the arc extinguishing chamber. For example, if the arc extinguishing chamber is large, the permanent magnets can be appropriately extended from the second and fourth quadrants to the first and third quadrants respectively). Roughly in the middle of the permanent magnet, near the contact area, the arc-starting portion 2043 and the arc-starting groove 2101c, the direction of the middle magnetic line of force 303 is shown in the figure. The arc extinguishing system arranged in this way forms a 45-degree oblique magnetic line of force 303 that can pass through the center of the contact, thereby forming a magnetic blowing force F at a direction corresponding to the arc-starting portion 2043 and the arc-starting groove 2101c that has an angle of 90 degrees with the magnetic line of force (in the electromagnetic system, the magnetic blowing force F is 90 degrees to the magnetic field. This point is highlighted in this embodiment to illustrate that at this position, the electromagnetic force F helps the arc to pass through the arc-starting groove 2101c and enter the arc extinguishing chamber). Help 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 a direction parallel to the X-axis. At this time, the magnetic lines of force 303 in the middle can only act on the arc in a direction 45 degrees upward. At this time, since the magnetic resistance at the position of the arc extinguishing chamber is smaller, the magnetic lines of force 303 on the edge side will have the effect of contracting toward the arc extinguishing chamber, so that the magnetic lines of force are deflected through the arc extinguishing chamber and reach the permanent magnet on the other side. In this way, the path of the magnetic lines of force is bent. These bent magnetic lines of force help the arc to move in a direction parallel to the X-axis, so as to make full use of the space of the arc extinguishing chamber to cool the arc and cool the high-temperature gas. In this structure of the present invention, the direction of the arc blowing is on the diagonal line, which makes the space for arc blowing larger, more conducive to arc breaking, stronger arc extinguishing ability, and higher space utilization of the product.

[0061] It should be pointed out that in the above embodiment, the static contact 202 is connected to the positive pole and the static contact 203 is connected to the negative pole, so the arc striking method is arranged in a clockwise direction, and the arc also moves in a clockwise direction into the arc extinguishing chamber, which determines the direction of the magnetic field. If the static contact 202 is connected to the negative pole and the static contact 203 is connected to the positive pole, then the arc striking direction needs to be arranged in a counterclockwise direction. According to the principle of the present invention, the arc striking of the moving contact 204, the position of the arc extinguishing chambers 210 and 211, the opening direction of the arc striking slot, the position of the permanent magnets 301 and 302, and the arrangement of the polarity are all arranged in a counterclockwise direction, such as Figure 6b .

[0062] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and equivalent changes made by using the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A DC contactor arc extinguishing system, the DC contactor comprises a contact system, an arc extinguishing system, an electromagnetic system and a housing; the housing is provided with a contact system, an arc extinguishing system and an electromagnetic system; the contact system comprises a static contact and a moving contact; the electromagnetic system comprises a driving central shaft, a static iron core, a moving iron core, a skeleton coil, a metal cup and a yoke; a contact system is provided above the electromagnetic system, and an arc extinguishing system is provided around the contact system; the characteristics are: The arc extinguishing system comprises an arc extinguishing chamber, an arc striking device and an arc isolating device; the arc extinguishing chamber is arranged at the outer periphery of the relative motion area between the moving contact and the stationary contact of the DC contactor, between the two stationary contacts; the moving contact and the arc extinguishing chamber are provided with an arc striking device; the arc isolating device is arranged in the housing; The arc striking device comprises an arc striking portion provided on the moving contact and an arc striking piece provided on the arc extinguishing chamber; the moving contact is provided with an arc striking portion extending toward the arc extinguishing chamber; the arc extinguishing chamber is provided with an arc striking piece extending toward the static contact at one end close to the static contact; The arc extinguishing chamber is provided with grid pieces arranged in parallel in layers, and the grid pieces are provided with bent heads along the direction of the arc path; the grid pieces are provided with arc-striking grooves corresponding to the arc-striking portions of the moving contacts; an arc-striking piece is provided at the top of the arc extinguishing chamber, and an end of the arc-striking piece close to the static contact is also provided with a bent head along the direction of the arc path and in the same direction as the bent head of the grid piece, and the length of the bent head of the arc-striking piece is greater than the length of the bent head of the grid piece.

2. A DC contactor arc extinguishing system as claimed in claim 1, characterized in that: The arc striking portion of the moving contact is configured as a bent portion extending from the moving contact plane along the direction of the arc path generated toward the arc extinguishing chamber.

3. A DC contactor arc extinguishing system as claimed in claim 1, characterized in that: The arc-isolating device comprises an arc-extinguishing cavity and an arc-isolating plate provided on the driving axis of the moving contact; the arc-extinguishing cavity is set to be cylindrical with the driving axis as the central axis, and an arc-extinguishing chamber and a contact system are provided in the arc-extinguishing cavity; the cylindrical arc-extinguishing cavity is open at one end close to the moving contact, and a base plate is provided at the other end; the cylindrical arc-extinguishing cavity is provided with a continuous cylindrical wall; two sections of arc-shaped partitions are arranged symmetrically relative to the center of the driving axis and are perpendicular to the base plate on the base plate; the top of the moving contact is provided with an arc-isolating plate perpendicular to the plane of the moving contact, and the arc-isolating plate is provided in the middle position of the top end of the moving contact to separate the two contact points of the moving contact and the static contact in two spaces.

4. A DC contactor arc extinguishing system as claimed in claim 3, characterized in that: The cylindrical wall of the cylindrical arc extinguishing cavity is composed of four right-angled sector-shaped arc surfaces of two different diameters arranged at intervals, and the connection point of two sections of right-angled sector-shaped arc surfaces of different diameters is arranged on the two static contact connection lines.

5. A DC contactor arc extinguishing system as claimed in claim 3, characterized in that: The substrate is provided with a through hole for passing two static contacts, and two sections of arc-shaped partitions perpendicular to the substrate are symmetrically arranged between the through holes of the two static contacts and between the arc extinguishing chamber and the moving contact relative to the center of the driving axis; one end of the arc-shaped partition is away from the bent head of the arc-striking piece and close to the static contact on one side, and the other end of the arc-shaped partition is arranged on the outside of the relative area between the bent head of the arc-striking piece and the static contact on the other side.

6. A DC contactor arc extinguishing system as claimed in claim 5, characterized in that: The arc partition is provided with a guide portion, and when the guide portion on the side of the arc partition close to the static contact gradually approaches the static contact, the gap formed between the guide portion and the cylindrical wall of the cylindrical arc extinguishing cavity gradually decreases.

7. A DC contactor arc extinguishing system as claimed in claim 6, characterized in that: The two arc-shaped partitions are each provided with two corresponding rib plates perpendicular to the base plate for limiting the movement guide of the moving contact. The rib plates on the same arc-shaped partition are arranged on both sides equidistant from the driving center axis. The corresponding rib plates and the arc-isolating plates of the driving center axis form a partition structure that separates the two contact points of the moving contact and the static contact into two spaces.

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