Arc extinguishing system and circuit breaker

Abstract

The arc extinguishing system comprises an arc extinguishing cavity, the arc extinguishing cavity is provided with an opening, a plurality of arc extinguishing grid sheets which are arranged at intervals are arranged in the arc extinguishing cavity in a surrounding manner, the plurality of arc extinguishing grid sheets are divided into three grid sheet groups, one grid sheet group is opposite to the opening at intervals, and the other grid sheet group is opposite to the opening at intervals. And the other two grid sheet groups are respectively arranged along two opposite sides of the opening, so that the three grid sheet groups are connected to form a U-shaped structure which is correspondingly communicated with the opening. According to the utility model, the plurality of arc extinguishing grid sheets are arranged in the arc extinguishing cavity in a surrounding manner, the arc extinguishing effect is improved by adding the arc extinguishing grid sheets, and the three grid sheet groups form the U-shaped structure in the arc extinguishing cavity in a surrounding manner, so that the arc extinguishing grid sheets of the two adjacent grid sheet groups are easier to lengthen the arc, and the arc extinguishing effect is improved.

Description

Technical Field

[0001] The utility model relates to the field of low-voltage electrical appliances, and particularly relates to an arc extinguishing system and a circuit breaker. Background Art

[0002] A circuit breaker is a device that plays an electrical protection role in a circuit. When the contact mechanism of the circuit breaker is opened, an arc will be instantly generated between its contacts, and at the same time, high-temperature and high-pressure gas will be generated. The outwardly ejected arc and high-temperature and high-pressure gas are likely to cause problems such as phase-to-phase breakdown and ablation of parts. Therefore, the arc extinguishing chamber arranged in cooperation with the contact mechanism is particularly important.

[0003] However, with the development of power systems such as power grids and new energy, due to structural and layout limitations, traditional arc extinguishing chambers are difficult to balance the development trends of high performance and miniaturization of circuit breakers. Limited by the internal space of the circuit breaker, only by increasing the number of arc extinguishing grid sheets to improve the arc extinguishing effect, the thickness and spacing of the arc extinguishing grid sheets cannot be guaranteed, resulting in poor arc extinguishing effect of the arc extinguishing chamber. In addition, the opening and closing of the contact mechanism are mostly outside the arc extinguishing cavity, and the requirement for arc ignition is relatively high. Summary of the Invention

[0004] The purpose of the utility model is to overcome at least one defect of the prior art, and provide an arc extinguishing system with high arc ignition and arc extinguishing efficiency and a circuit breaker configured with the arc extinguishing system.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model provides an arc extinguishing system, including an arc extinguishing cavity. The arc extinguishing cavity is provided with an opening. A plurality of spaced-apart arc extinguishing grid sheets are arranged around in the arc extinguishing cavity. The plurality of arc extinguishing grid sheets are divided into three grid sheet groups. One of the grid sheet groups is spaced opposite to the opening, and the other two grid sheet groups are respectively arranged along the opposite sides of the opening, so that the three grid sheet groups are connected to form a U-shaped structure corresponding to and communicating with the opening.

[0007] Further, the grid sheet group opposite to the opening is the first grid sheet group. The plurality of arc extinguishing grid sheets of the first grid sheet group are first arc extinguishing grid sheets. A first arc extinguishing gap is formed between adjacent two first arc extinguishing grid sheets. One end of the first arc extinguishing gap is opposite to the opening.

[0008] The grid sheet group arranged along one side of the opening is the second grid sheet group. The plurality of arc extinguishing grid sheets of the second grid sheet group are second arc extinguishing grid sheets. A second arc extinguishing gap is formed between adjacent two second arc extinguishing grid sheets. One end of the second arc extinguishing gap is opposite to the first grid sheet group, so that the plurality of arc extinguishing grid sheets in the arc extinguishing cavity as a whole form a U-shaped structure.

[0009] Furthermore, the included angle range between the extending direction of the first arc extinguishing grid plate and the first direction is 0 to 20°, the included angle range between the extending direction of the second arc extinguishing grid plate and the second direction is 0 to 30°, and the first direction is perpendicular to the second direction.

[0010] Furthermore, the first grid plate group is provided with a first arc extinguishing groove, each second grid plate group is provided with a second arc extinguishing groove, the first arc extinguishing groove communicates between the two second arc extinguishing grooves, the groove line of the first arc extinguishing groove is arranged parallel to the second direction, and the included angle range between the groove line of the second arc extinguishing groove and the first direction is 0 to 30°, and the first direction is perpendicular to the second direction.

[0011] Furthermore, a connecting grid plate is connected between adjacent two grid plate groups, and the middle part of the connecting grid plate is bent so that the two ends of the connecting grid plate are respectively opposite to the arc extinguishing grid plates of the adjacent grid plate groups at intervals.

[0012] Furthermore, the connecting grid plate is provided with an engaging groove, and the two ends of the engaging groove respectively communicate with the arc extinguishing grooves of the adjacent two grid plate groups correspondingly.

[0013] Furthermore, a transition grid plate group is connected between adjacent two grid plate groups, and the transition grid plate group includes a plurality of transition grid plates arranged at intervals.

[0014] Furthermore, a contact mechanism is arranged on one side of the arc extinguishing cavity in a matching manner. The contact mechanism includes two moving contact components rotatably assembled side by side. The open ends allow the two moving contact components to extend into the arc extinguishing cavity, and the two moving contact components contact or separate within the arc extinguishing area formed by the enclosure of the three grid plate groups.

[0015] Furthermore, it further includes at least one arc extinguishing chamber. In the internal space of each arc extinguishing chamber, at least one grid plate group is arranged as at least a part of the arc extinguishing cavity.

[0016] Furthermore, it includes one arc extinguishing chamber. One side of the arc extinguishing chamber is provided with an open end. The internal space of the arc extinguishing chamber serves as the arc extinguishing cavity and is provided with three grid plate groups. At least one grid plate group corresponds to the exhaust hole opened in the arc extinguishing cavity.

[0017] Furthermore, it includes two arc extinguishing chambers arranged side by side. The interiors of the two arc extinguishing chambers communicate with each other to form an arc extinguishing cavity. Open ends are provided on the same side of the two arc extinguishing chambers. One grid plate group opposite to the open end is divided into two sub-grid plate groups, and the two sub-grid plate groups are respectively arranged in the two arc extinguishing chambers. The other two grid plate groups are respectively arranged in the two arc extinguishing chambers and correspond to the side of the open end.

[0018] Furthermore, an assembly gap is left between the two sub-grid plate groups. One end of the assembly gap corresponds to between the two moving contact components in the closing position, and the other end communicates with the outside of the arc extinguishing chamber.

[0019] Further, it includes three arc extinguishing chambers arranged side by side. The interiors of the three arc extinguishing chambers are interconnected to form an arc extinguishing cavity. An opening is provided on one side of the arc extinguishing chamber located in the middle position. Three sets of grid plates are respectively arranged in the three arc extinguishing chambers. One set of grid plates is spaced opposite to the opening, and the other two sets of grid plates are respectively arranged along one side of the opening.

[0020] Further, it also includes a pair of arc ignition angles arranged at intervals. One end of each arc ignition angle extends to one side of the opening, and the other end is connected to the set of grid plates adjacent to one side of the opening.

[0021] Further, it also includes at least a pair of magnets arranged at intervals outside the arc extinguishing cavity. Each magnet covers the outside of the arc extinguishing cavity between one side of the opening and the adjacent set of grid plates.

[0022] Further, at least one side of the arc extinguishing cavity is provided with exhaust holes, and the exhaust holes are communicated with an exhaust port provided on the housing. The exhaust port is covered with an arc extinguishing component.

[0023] The present utility model also provides a circuit breaker, which includes a housing. An exhaust port is provided on the side wall of the housing. The arc extinguishing system as described above is arranged inside the housing, and the exhaust port is communicated with the exhaust holes provided in the arc extinguishing cavity.

[0024] Preferably, a guiding portion is provided on the inner side wall of the housing connected between the two exhaust ports, and the guiding portion is an arc-shaped surface that is high in the middle and low on both sides.

[0025] Preferably, a guiding inclined surface is connected between the guiding portion and the lowest point of each exhaust port.

[0026] The present utility model also provides a circuit breaker, which includes a housing and the arc extinguishing system as described above. The contact mechanism further includes auxiliary contacts. The auxiliary contacts are assembled in the assembly gap, and the two moving contact assemblies are respectively in contact with or separated from the opposite sides of the auxiliary contacts.

[0027] The arc extinguishing system and the circuit breaker of the present utility model surround and arrange multiple arc extinguishing grid plates in the arc extinguishing cavity. By increasing the arc extinguishing grid plates, the arc extinguishing effect is improved. The three sets of grid plates form a U-shaped structure in the arc extinguishing cavity, making it easier to stretch the arc between the arc extinguishing grid plates of adjacent two sets of grid plates, which is beneficial to improving the arc extinguishing effect.

[0028] In addition, connecting grid plates or transition grid plate groups are arranged between adjacent two sets of grid plates. The arc is guided to flow between adjacent two sets of grid plates by the connecting grid plates or transition grid plate groups, improving the arc ignition and arc extinguishing effects.

[0029] In addition, when the contact mechanism is the cooperation of two moving contact assemblies, the two moving contacts extend into the arc extinguishing cavity and contact and separate in the arc extinguishing cavity. The arc generated during breaking is directly located in the arc extinguishing cavity, further improving the arc extinguishing effect.

[0030] In addition, the three grid plate groups can share one arc extinguishing chamber or can be separately arranged in two or more arc extinguishing chambers, which is conducive to meeting different product requirements. Description of the Drawings

[0031] Figure 1 is a schematic diagram of the internal structure of the circuit breaker of the present utility model;

[0032] Figure 2 is a schematic diagram of the internal structure of the circuit breaker of the present utility model during opening (excluding auxiliary contacts);

[0033] Figure 3 is a schematic diagram of the internal structure of the circuit breaker of the present utility model during closing (excluding auxiliary contacts);

[0034] Figure 4 is a schematic diagram of the structure of the arc extinguishing chamber in the present utility model;

[0035] Figure 5 is an exploded view of the arc extinguishing chamber in the present utility model;

[0036] Figure 6 is a schematic diagram of the structure of the three grid plate groups and the connecting grid plates in the present utility model;

[0037] Figure 7 is a cross-sectional view of the arc extinguishing chamber in the present utility model (including the transition grid plate group);

[0038] Figure 8 is a schematic diagram of the arc extinguishing chamber in the present utility model Figure 1 (the first embodiment of the arc extinguishing system);

[0039] Figure 9 is a schematic diagram of the arc extinguishing chamber in the present utility model Figure 2 (the first embodiment of the arc extinguishing system);

[0040] Figure 10 is a schematic diagram of the arc extinguishing chamber in the present utility model Figure 3 (the first embodiment of the arc extinguishing system);

[0041] Figure 11 is a schematic diagram of the arc extinguishing chamber in the present utility model (the second embodiment of the arc extinguishing system);

[0042] Figure 12 is a schematic diagram of the arc extinguishing chamber in the present utility model (the third embodiment of the arc extinguishing system);

[0043] Figure 13 is an exploded view of 12;

[0044] Reference Numerals:

[0045] 104 - Exhaust port, 105 - Flow - guiding part, 1051 - Flow - guiding inclined plane, 1a - Base, 1b - First support plate, 1c1 - Blocking part, 1d - Cover body, 2 - Operating mechanism, 20 - Traction rod, 21 - Operating part, 22 - Link assembly, 3 - Contact mechanism, 33 - Rotating shaft, 34 - Moving contact, 4 - Arc - extinguishing system, 4a - Arc - extinguishing cavity, 40 - Arc - extinguishing chamber, 41 - Open end, 42 - First grid - plate group, 421 - Sub - grid - plate group, 42a - Assembly gap, 43 - Second grid - plate group, 44 - Connecting grid - plate, 45 - Transition grid - plate group, 46 - Arc - initiating angle, 47 - Magnet, 48 - Gas - generating part, 481 - Installation groove, 49 - Arc - suppressing part, 5 - Thermal - magnetic tripping mechanism, 51 - Bimetallic strip, 52 - Armature, 6 - Wiring assembly, 61 - Wiring terminal, 62 - Connecting plate. Detailed implementation manners

[0046] The following embodiments given in conjunction with the drawings further illustrate the detailed implementation manners of the arc - extinguishing system and the circuit breaker of the present utility model. The arc - extinguishing system and the circuit breaker of the present utility model are not limited to the descriptions of the following embodiments.

[0047] As Figures 1-3 shown, the circuit breaker includes a housing. An operating mechanism 2 and at least one conductive system are arranged inside the housing. The operating mechanism 2 is rotatably assembled inside the housing, and the operating part 21 connected to the operating mechanism 2 extends outside the housing. A traction rod 20 is rotatably assembled on one side of the operating mechanism 2, and the operating mechanism 2 is tripped by the traction rod 20. Each conductive system includes a contact mechanism 3, an arc - extinguishing system 4, and a thermal - magnetic tripping mechanism 5. The contact mechanism 3 is used to control the on - off of the main circuit in each conductive system. The contact mechanism 3 of at least one conductive system is drivingly connected to the operating mechanism 2. The moving - contact assemblies of adjacent two conductive systems are linked. By driving the operating mechanism 2, the contact mechanisms 3 of each conductive system can be synchronously switched on and off. The arc - extinguishing system 4 is disposed on one side of the contact mechanism 3 and is used to extinguish the arc generated when the contact mechanism 3 is disconnected. The arc - extinguishing system 4 includes an arc - extinguishing cavity 4a. The arc - extinguishing cavity 4a is provided with an open end 41 for the arc to enter the arc - extinguishing cavity 4a. The exhaust gas generated by the arc - extinguishing system 4 when extinguishing the arc is discharged from the exhaust port 104 opened on the housing. The thermal - magnetic tripping mechanism 5 is connected to the main circuit. When a short - circuit or overload fault occurs in the main circuit, the thermal - magnetic tripping mechanism 5 operates and triggers the operating mechanism 2 to trip by driving the traction rod 20. Specifically, the contact mechanism 3 includes a moving - contact assembly and a static contact that cooperate with each other. The moving - contact assembly in at least one conductive system is drivingly connected to the operating mechanism 2. The operating mechanism 2 drives the moving - contact assembly to rotate towards or away from the static contact, so as to realize the on - off of the contact mechanism 3. Or, the contact mechanism 3 includes two moving - contact assemblies that are rotatably assembled side by side. One of the moving - contact assemblies in at least one conductive system is drivingly connected to the operating mechanism 2. The operating mechanism 2 drives the two moving - contact assemblies to rotate towards each other to contact or rotate away from each other to separate, so as to realize the on - off of the contact mechanism 3.

[0048] As Figures 1-4 shown, the improvement of this application lies in that a plurality of arc extinguishing grid sheets arranged at intervals are arranged around in the arc extinguishing chamber 4a. The plurality of arc extinguishing grid sheets are divided into three grid sheet groups. One of the grid sheet groups is spaced opposite to the opening 41, and the other two grid sheet groups are respectively arranged along the opposite two sides of the opening 41, so that the three grid sheet groups are connected to form a U-shaped structure corresponding to and communicating with the opening 41.

[0049] In this way, by arranging a plurality of arc extinguishing grid sheets around in the arc extinguishing chamber and improving the arc extinguishing effect by increasing the arc extinguishing grid sheets, the three grid sheet groups form a U-shaped structure around in the arc extinguishing chamber, making it easier to elongate the arc between adjacent two grid sheet groups, which is beneficial to improving the arc extinguishing effect.

[0050] Specifically, as Figures 5-13 shown, the grid sheet group opposite to the opening 41 is the first grid sheet group 42. The plurality of arc extinguishing grid sheets of the first grid sheet group 42 are the first arc extinguishing grid sheets. A first arc extinguishing gap is formed between adjacent two first arc extinguishing grid sheets. One end of the first arc extinguishing gap is opposite to the opening 41. The plurality of first arc extinguishing grid sheets are arranged at intervals along an approximately parallel direction to each other. The grid sheet group arranged along one side of the opening 41 is the second grid sheet group 43. The plurality of arc extinguishing grid sheets of the second grid sheet group 43 are the second arc extinguishing grid sheets. A second arc extinguishing gap is formed between adjacent two second arc extinguishing grid sheets. One end of the second arc extinguishing gap is opposite to the first grid sheet group 42, so that the plurality of arc extinguishing grid sheets in the arc extinguishing chamber 4a as a whole form a U-shaped structure. Compared with the existing arc extinguishing chamber 4a, it has more arc extinguishing grid sheets, and the arc extinguishing area formed by their enclosure is more conducive to extinguishing the arc.

[0051] Preferably, a connecting grid sheet 44 (see Figure 6 、 8 -13) or a transition grid sheet group 45 (see Figure 7 ) is arranged between adjacent two grid sheet groups. The connecting grid sheet 44 or the transition grid sheet group 45 guides the arc to flow between adjacent two grid sheet groups, improving the arc leading and arc extinguishing effects.

[0052] Preferably, the arc extinguishing system 4 further includes at least one arc extinguishing chamber 40. At least one grid sheet group is arranged in the internal space of each arc extinguishing chamber 40 as at least a part of the arc extinguishing chamber 4a. That is to say, the three grid sheet groups can share one arc extinguishing chamber 40, or can be respectively arranged in two or more arc extinguishing chambers 40, which is applicable to circuit breakers with different requirements.

[0053] Preferably, when the contact mechanism 3 includes two moving contact assemblies arranged side by side, the opening 41 of the arc extinguishing chamber 4a allows the two moving contact assemblies to extend into the arc extinguishing chamber 4a, and the two moving contact assemblies contact or separate within the arc extinguishing area formed by the combination of three grid plates. In this way, by arranging multiple arc extinguishing grid plates around the arc extinguishing chamber 4a, the arc extinguishing effect is improved by increasing the arc extinguishing grid plates. At the same time, the two moving contact assemblies of the contact mechanism 3 extend into the arc extinguishing chamber 4a and contact and separate within the arc extinguishing chamber 4a, and the arc generated during breaking is directly located within the arc extinguishing chamber 4a, further improving the arc extinguishing effect. Of course, when the contact mechanism 3 includes a moving contact assembly and a static contact that cooperate with each other, the static contact is arranged on one side of the opening 41, and the moving contact assembly rotates from the other side of the opening 41 towards the direction close to the static contact, and closing is achieved after the moving contact assembly contacts the static contact.

[0054] Combined with Figures 1-13 Provide a specific embodiment of a circuit breaker.

[0055] As Figure 1 shown, the circuit breaker includes a housing. Taking the height direction of the housing as the first direction, that is Figure 1 the up and down direction in Figure 1 Taking the length direction of the housing as the second direction, that is Figure 1 the left and right direction in

[0056] Taking the thickness direction of the housing as the third direction, that is

[0057] The operating mechanism 2, the contact mechanism 3, and the arc extinguishing system 4 are stacked in sequence within the housing. In this embodiment, the operating mechanism 2, the contact mechanism 3, and the arc extinguishing system 4 are stacked in sequence in the first direction. That is, the space within the housing is sequentially divided into a first assembly cavity 101, a second assembly cavity, and a third assembly cavity that are stacked in the first direction. The operating mechanism 2 and the traction rod 20 are rotatably arranged within the first assembly cavity. The operating member 21 extends from the side away from the third assembly cavity to the outside of the housing 1 for driving the operating mechanism 2. The connecting rod assembly 22 of the operating mechanism 2 extends into the second assembly cavity for driving the contact mechanism 3; the thermal magnetic trip mechanism 5 is arranged within the first assembly cavity, facilitating cooperation with the traction rod 20. Of course, the thermal magnetic trip mechanism 5 can also be arranged in the second assembly cavity, enabling the thermal magnetic trip mechanism 5 to extend into the first assembly cavity to cooperate with the traction rod 20; the arc extinguishing system 4 is separately arranged within the third assembly cavity, enabling the arc extinguishing system 4 to have more assembly space, facilitating an increase in the arc extinguishing space. In this embodiment, the operating mechanism 2, the traction rod 20, the thermal magnetic trip mechanism 5, and the wiring assembly 6 adopt existing technologies.

[0058] As Figure 1 , 2 shown, the contact mechanism 3 includes two moving contact assemblies that are rotatably assembled side by side. The two moving contact assemblies are linked through a linkage mechanism or a gear transmission mechanism. One of the moving contact assemblies is drivingly connected to the operating mechanism 2. The operating mechanism 2 drives the two moving contact assemblies to rotate towards each other in contact or away from each other in separation. The two moving contact assemblies rotate towards or away from each other synchronously and stably, increasing the opening distance of the contact mechanism 3 and also doubling the opening speed of the contact mechanism 3, which is beneficial for improving the breaking performance of the circuit breaker.

[0059] Specifically, each moving contact assembly includes a rotating shaft 33 and a moving contact 34. Among them, the rotating shaft 33 is rotatably arranged within the second assembly cavity of the housing. The moving contact 34 is coaxially assembled with the rotating shaft 33 and is drivingly matched. The linkage mechanism includes at least one connecting rod hinged between the two rotating shafts 33. Its structure is simple and the linkage effect is good. Further, the linkage mechanism further includes a guiding member. The guiding member is provided with a guiding groove, and the linkage mechanism is slidably matched with the guiding groove to limit the movement trajectory of the connecting rod; the gear transmission mechanism includes two meshing gear parts. Each gear part is arranged along the circumferential side wall of a rotating shaft 33. The gear part can be provided by a gear or an incomplete gear fixed to the rotating shaft.

[0060] Further, as Figure 1As shown, the contact mechanism 3 further includes an auxiliary contact 38. The auxiliary contact 38 is arranged between the two moving contact assemblies. When the two moving contact assemblies are driven to rotate towards each other, the two moving contact assemblies can respectively contact the auxiliary contact 38 to connect the main circuit. When the two moving contact assemblies are driven to rotate away from each other, the two moving contact assemblies can respectively separate from the auxiliary contact 38 to disconnect the main circuit, which is beneficial to increasing the overtravel, ensuring the contact pressure of the contact mechanism 3 during contact and reducing the contact resistance, and improving the overall breaking performance and stability.

[0061] Preferably, the auxiliary contact 38 can be a conductive part. One end of the auxiliary contact 38 is fixed inside the housing, and the front and back sides of the other end of the auxiliary contact 38 are respectively used to contact the two moving contact assemblies. Of course, auxiliary contact points can also be arranged on the front and back sides of the other end of the auxiliary contact 38, and each auxiliary contact point cooperates with the moving contact point of a moving contact assembly.

[0062] As Figures 1-4 shown, the arc extinguishing system 4 is arranged in the third assembly cavity. The arc extinguishing system 4 includes an arc extinguishing cavity 4a. An opening 41 is formed on the side of the arc extinguishing cavity 4a facing the contact mechanism 3. A plurality of arc extinguishing grid sheets arranged at intervals are arranged around the arc extinguishing cavity 4a. Among them, the plurality of arc extinguishing grid sheets are divided into three grid sheet groups. One grid sheet group is used as the first grid sheet group 42 and is arranged on the side opposite to the opening 41 at intervals, and the other two grid sheet groups are used as the second grid sheet groups 43 and are respectively arranged along the opposite sides of the opening 41. The moving contact assemblies extend from the opening 41 into the arc extinguishing cavity 4a, and the two moving contact assemblies contact or separate in the arc extinguishing area surrounded by the three grid sheet groups. More arc extinguishing grid sheets can be arranged in the arc extinguishing cavity 4a, improving the arc extinguishing effect. At the same time, the arc generated when the contact mechanism 3 breaks is directly located in the arc extinguishing cavity 4a, further improving the arc extinguishing effect.

[0063] Specifically, the plurality of arc extinguishing grid sheets in the first grid sheet group 42 are first arc extinguishing grid sheets, and a first arc extinguishing gap is formed between adjacent two first arc extinguishing grid sheets. One end of the first arc extinguishing gap faces the opening 41. The plurality of arc extinguishing grid sheets in the second grid sheet group 43 are second arc extinguishing grid sheets, and a second arc extinguishing gap is formed between adjacent two second arc extinguishing grid sheets. One end of the second arc extinguishing gap faces the first grid sheet group 42. Preferably, the first grid sheet group 42 is provided with a first arc extinguishing groove, and each second grid sheet group 43 is provided with a second arc extinguishing groove. The first arc extinguishing groove communicates between the two second arc extinguishing grooves. The groove line of the first arc extinguishing groove is arranged parallel to the second direction, and the included angle range between the groove line of the second arc extinguishing groove and the first direction is 0 to 30°, which is beneficial to the circulation of the arc in the first arc extinguishing groove and the second arc extinguishing groove.

[0064] Furthermore, the included angle range between the extending direction of the first arc extinguishing grid plate and the first direction is 0 to 20°, and the included angle range between the extending direction of the second arc extinguishing grid plate and the second direction is 0 to 30°. This makes the arrangement form of the multiple arc extinguishing grid plates more flexible and is conducive to making full use of the space in the arc extinguishing chamber 4a.

[0065] Preferably, as Figure 5 and 7 shown in Fig. -12, a connecting grid plate 44 is arranged between two adjacent grid plate groups. The middle of the connecting grid plate 44 is bent so that the two ends of the connecting grid plate 44 are spaced opposite to the arc extinguishing grid plates of the adjacent grid plate groups respectively, which is conducive to the flow of the arc between the two grid plate groups. Of course, two adjacent grid plate groups can also be connected by a transition grid plate group 45.

[0066] Furthermore, the arc extinguishing system 4 includes an arc extinguishing chamber 40 and an arc extinguishing element 49. At least one inner shell is arranged in the outer shell, and at least one inner shell is arranged in each third assembly cavity 103. The number of arc extinguishing chambers 40 can be one, two or more than two. The internal space of each arc extinguishing chamber 40 is at least used as part of the arc extinguishing chamber for arranging at least one grid plate group. The arc extinguishing chambers 40 of the same arc extinguishing system 4 are assembled in one inner shell. A second avoidance groove corresponding to the opening 41 is opened on the side of the inner shell facing the contact mechanism 3. The opposite ends of the inner shell are respectively open and communicated with the exhaust ports 104 opened on the outer shell. Through the inner shell, the arc extinguishing chamber 40 and the arc extinguishing grid plates, arc ignition angles, etc. arranged in the arc extinguishing chamber 40 can be formed into a whole, which is conducive to forming a modularization and convenient for assembly.

[0067] Preferably, as Figure 1 、 2 shown in the figure, the arc extinguishing system 4 further includes a diversion part 105 arranged in the outer shell. The diversion part 105 is at least arranged on one side of the exhaust port 104. The diversion part 105 can be arranged independently or formed by the inner wall of the outer shell. In this embodiment, the exhaust ports 104 are located on the opposite sides of the outer shell, and the diversion part 105 is arranged on the inner side wall of the outer shell connecting the two exhaust ports 104. The diversion part 105 guides the tail gas discharged from the arc extinguishing chamber 40 to the exhaust port 104.

[0068] Preferably, as Figure 3 shown in the figure, a diversion inclined surface 1051 is connected between the diversion part 105 and the lowest point of each exhaust port 104. In the figure, the diversion inclined surface 1051 is formed at the position of the diversion inclined surface 1051. The diversion inclined surface 1051 can be a section of inclined surface or a series of inclined surfaces with different inclination angles connected in sequence.

[0069] Combined with Figures 1-10 the first structure of the arc extinguishing system 4 is provided.

[0070] As Figures 4-9As shown, the arc extinguishing system 4 includes an arc extinguishing chamber 40. The arc extinguishing chamber 40 includes a pair of fixed plates arranged at intervals, and an arc extinguishing cavity 4a that is open on all four sides is formed between the pair of fixed plates. A plurality of arc extinguishing grid plates are arranged at intervals between the pair of fixed plates. Figure 4 One side opening along the length direction of the fixed plate is used as the opening 41, and the openings in the other three directions are all used as exhaust holes for exhausting tail gas. A plurality of arc extinguishing grid plates are arranged around the arc extinguishing cavity 4a to form a U-shaped structure opposite to the opening 41. Preferably, the U-shaped structure formed by the plurality of arc extinguishing grid plates is symmetric about the central axis of the opening 41. The plurality of arc extinguishing grid plates are divided into a first grid plate group 42 and two second grid plate groups 43. The first grid plate group 42 is spaced opposite to the opening 41, and the two second grid plate groups 43 are respectively arranged along the opposite sides of the opening 41. Two moving contact assemblies extend into the arc extinguishing cavity 4a from the opening 41, and the two moving contact assemblies contact or separate within the arc extinguishing area formed by the enclosure of the first grid plate group 42 and the two second grid plate groups 43.

[0071] Among them, the plurality of arc extinguishing grid plates of the first grid plate group 42 are first arc extinguishing grid plates. The plurality of first arc extinguishing grid plates are arranged along the second direction. A first arc extinguishing gap is formed between adjacent two first arc extinguishing grid plates. One end of each first arc extinguishing gap is opposite to the opening 41, and the exhaust hole opposite to the opening 41 communicates with the other end of each first arc extinguishing gap. The included angle range between the extending direction of each first arc extinguishing grid plate and the first direction is 0 to 20°. A first arc extinguishing notch is provided at one end of each first arc extinguishing grid plate, and all the first arc extinguishing notches communicate to form a first arc extinguishing groove. The groove line of the first arc extinguishing groove is parallel to the second direction and is opposite to the opening 41. As Figure 8 、 9 shown, the extending direction of each first arc extinguishing grid plate is arranged parallel to the first direction. Adjacent two first arc extinguishing grid plates are parallel and equidistant. The moving contact assembly can move within the first arc extinguishing groove. As Figure 7 、 10 shown, the extending direction of one or more first arc extinguishing grid plates located in the middle position of the first grid plate group 42 is arranged parallel to the first direction, and the extending directions of the remaining first arc extinguishing grid plates form an included angle with the first direction, and the first grid plate group 42 is symmetric about the central axis of the opening 41.

[0072] The multiple arc extinguishing grid plates of the second grid plate group 43 are second arc extinguishing grid plates. The multiple second arc extinguishing grid plates are arranged substantially along the first direction or arranged at an angular direction with respect to the first direction. Each second arc extinguishing grid plate is arranged along the second direction or arranged at an angular direction with respect to the second direction, so that two second grid plate groups 43 and one first grid plate group 42 surround to form a U-shaped structure. A second arc extinguishing gap is formed between two adjacent second arc extinguishing grid plates. One end of each second arc extinguishing gap faces the first grid plate group 42, and the exhaust hole adjacent to the opening 41 is communicated with the other end of the second arc extinguishing gap. The included angle range between the extending direction of each second arc extinguishing grid plate and the second direction is 0 to 30°. A second arc extinguishing notch is formed at one end of each second arc extinguishing grid plate, and all the second arc extinguishing notches are communicated to form a second arc extinguishing groove. The two ends of the first arc extinguishing groove are respectively correspondingly communicated with one end of the two second arc extinguishing grooves, as Figure 8 shown, the extending directions of the second arc extinguishing grid plates are all arranged parallel to the second direction, and two adjacent second arc extinguishing grid plates are arranged at equal intervals, as Figure 7 and 9 -11 shown, the extending direction of the second arc extinguishing grid plates is arranged at an angular direction with respect to the second direction, and one end of each second arc extinguishing grid plate is inclined towards the direction of the first grid plate group 42. The intervals between two adjacent second arc extinguishing grid plates can be arranged at equal intervals or in a radial pattern. In this embodiment, the shapes of the first arc extinguishing notch and the second arc extinguishing notch are not specifically limited and can be square, trapezoidal or V-shaped.

[0073] Further, as Figure 5 、 6 and 8-11 shown, a connecting grid plate 44 is arranged between the first grid plate group 42 and the second grid plate group 43, so that the arc flows between the two grid plate groups along the connecting grid plate 44, Figure 5 、 6 in, the middle of the connecting grid plate 44 is bent, so that the two ends of the connecting grid plate 44 are respectively spaced opposite to the adjacent arc extinguishing grid plates. Preferably, the distance between one end of the connecting grid plate 44 and the first arc extinguishing grid plate is approximately equal to the first arc extinguishing gap, and the distance between the other end of the connecting grid plate 44 and the second arc extinguishing grid plate is approximately equal to the second arc extinguishing gap. The connecting grid plate 44 is provided with a connection groove. Preferably, the connection groove includes a first connection area and a second connection area, wherein the first connection area is correspondingly communicated with one end of the first arc extinguishing groove, and the second connection area is correspondingly connected with one end of the second arc extinguishing groove, so as to ensure the corresponding communication between the first arc extinguishing groove and the second arc extinguishing groove and facilitate the flow of the arc between the grid plate groups.

[0074] Of course, as Figure 7 shown, a transition grid plate group 45 can also be arranged between the first grid plate group 42 and the second grid plate group 43. The transition grid plate group 45 includes a plurality of transition grid plates arranged at intervals. Preferably, the transition grid plates located at the side positions of the transition grid plate group 45 are spaced opposite to the arc extinguishing grid plates at the side positions of the adjacent grid plate groups.Figure 7 Among them, the transition grid piece groups 45 are respectively arranged on both sides of the first grid piece group 42, and a plurality of transition grid pieces of each transition grid piece group 45 are arranged at intervals substantially along the second direction. The transition grid piece group 45 is provided with a communicating transition arc extinguishing groove, and the transition arc extinguishing groove communicates between the first arc extinguishing groove and the second arc extinguishing groove.

[0075] As Figure 4 、 5 shown, the arc extinguishing chamber 40 further includes at least a pair of gas generating members 48. A pair of gas generating members 48 are arranged oppositely at intervals on opposite sides within the opening 41. Each gas generating member 48 is provided with a plurality of slots, and each arc extinguishing grid piece is correspondingly inserted into a slot, so that the grid piece legs on both sides of the arc extinguishing notch in each arc extinguishing grid piece are wrapped within the gas generating member 48. It can also be understood that the gas generating members 48 are respectively on opposite sides of the arc extinguishing groove; the gas generating member 48 is correspondingly provided with an installation groove 481 at the opening 41, and the arc ignition angle 46 is inserted into the installation groove 481 for arc ignition. Figure 4 Among them, each gas generating member 48 is provided with a pair of installation grooves 481. The pair of installation grooves 481 of the same gas generating member 48 are arranged on opposite sides of the opening 41 in the second direction. The two installation grooves 481 of the two gas generating members 48 located on the same side of the opening 41 are spaced oppositely in the third direction. A pair of arc ignition angles 46 are respectively assembled in the installation grooves 481. One end of each arc ignition angle 46 extends to one side of the opening 41, and the other end is connected to the grid piece group adjacent to one side of the opening 41, that is, spaced oppositely from the adjacent second arc extinguishing grid piece. Of course, the number of gas generating members 48 can also be set according to the number of grid piece groups and actual requirements.

[0076] Furthermore, the arc extinguishing system 4 further includes at least a pair of magnets 47 spaced outside the arc extinguishing chamber 4a. Each magnet 47 covers the outside of the arc extinguishing chamber 4a from one side of the opening 41 to the adjacent grid piece group, forming a magnetic field that pushes the arc to move between the opening 41 and the adjacent grid piece group. In this embodiment, the magnet 47 can be fixedly arranged within the housing.

[0077] Preferably, as Figures 1-3 shown, the arc extinguishing system 4 further includes a diversion part 105. The diversion part 105 is formed by the housing. In the figure, at least a pair of exhaust ports 104 are respectively opened on opposite sides of the housing. Each pair of exhaust ports 104 are spaced oppositely in the second direction. The arc extinguishing chamber 40 is arranged between at least a pair of exhaust ports 104. The diversion part 105 is formed by the inner side wall of the housing located between a pair of exhaust ports 104. In the figure, the diversion part 105 is formed by the bottom wall of the housing. The protruding height of the diversion part 105 changes with the distance from the exhaust port 104. The diversion part 105 is an arc-shaped surface that is high in the middle and low on both sides, and the protruding height is adjusted to a height that is conducive to connecting with the exhaust port 104 at the position closest to the exhaust port 104, which is conducive to guiding the exhaust gas discharged from the arc extinguishing chamber 40 to the exhaust port 104.

[0078] Preferably, as Figure 3 shown, a diversion slope 1051 is connected between the diversion part 105 and the lowest point of each exhaust port 104. In the figure, the diversion slope 1051 is formed at the position of the diversion slope 1051. The diversion slope 1051 can be a section of inclined surface or a series of inclined surfaces with different inclination angles connected in sequence, which is beneficial to introducing the electric arc into the arc extinguishing grid near the exhaust port 104, effectively increasing the arc voltage and extinguishing the electric arc.

[0079] In this embodiment, at least one arc extinguishing part 49 is also covered at each exhaust port 104. The arc extinguishing part 49 can be one or more stacked metal mesh plates.

[0080] It should be noted that when the contact mechanism 3 further includes an auxiliary contact 38, on the basis of the above structure, an assembly position is provided for the auxiliary contact 38. As Figure 1 shown, an assembly gap 42a (not shown, but can be referred to Figure 11 ) for assembling the auxiliary contact 38 is reserved in the first grid group 42. The central axis of the assembly gap 42a is collinear with the central axis of the opening 41. The assembly gap 42a is formed by the interval between two adjacent first arc extinguishing grids. The spacing of the assembly gap 42a is greater than the spacing of the first arc extinguishing gap. One end of the auxiliary contact 38 is fixed inside the housing, and the other end extends from the assembly gap 42a to the arc extinguishing chamber and cooperates with the two moving contact assemblies.

[0081] Combined with Figure 11 A second structure of the arc extinguishing system 4 is provided.

[0082] The arc extinguishing system 4 includes two arc extinguishing chambers 40 arranged side by side. Each arc extinguishing chamber 40 includes a pair of spaced fixed plates, so that each arc extinguishing chamber 40 forms a structure with four open sides. The interiors of the two arc extinguishing chambers 40 are connected to form an arc extinguishing chamber 4a. The open sides of the two arc extinguishing chambers 40 in the same direction serve as the opening 41 of the arc extinguishing chamber 4a. A group of second grid groups 43 are arranged in each arc extinguishing chamber 40. The first grid group 42 is divided into two sub-grid groups 421, and each sub-grid group 421 is correspondingly assembled in an arc extinguishing chamber 40. A connection grid 44 or a transition grid group 45 is arranged between each sub-grid group 421 and a second grid group 43. In this embodiment, the multiple first arc extinguishing grids in the first grid group 42, the multiple second arc extinguishing grids in the second grid group 43, the connection grid 44, and the transition grid group 45 can be specifically referred to the structure of the first arc extinguishing system 4.

[0083] In addition, a gas generating part 48, an arc ignition angle 46, a magnet 47, a diversion part 105, and an arc extinguishing part 49 can also be cooperatively arranged, and their structures can be referred to the structure of the first arc extinguishing system 4.

[0084] It should be noted that when the contact mechanism 3 further includes an auxiliary contact 38, an assembly gap 42a for assembling the auxiliary contact 38 is reserved in the first grid group 42. The assembly gap 42a is located between the two arc extinguishing chambers 40 and the two sub-grid groups 421. The central axis of the assembly gap 42a is collinear with the central axis of the opening 41. The assembly gap 42a is formed by the interval between two adjacent first arc extinguishing grid plates. The spacing of the assembly gap 42a is greater than the spacing of the first arc extinguishing gap. One end of the auxiliary contact 38 is fixed inside the housing, and the other end extends into the arc extinguishing chamber 4a from the assembly gap 42a to cooperate with the two moving contact assemblies.

[0085] Combined with Figure 12 、 13 Provide the structure of the third arc extinguishing system 4.

[0086] The arc extinguishing system 4 includes three arc extinguishing chambers 40 arranged side by side. Each arc extinguishing chamber 40 includes a pair of fixed plates arranged at intervals, so that each arc extinguishing chamber 40 forms a structure with four open sides. The interiors of the three arc extinguishing chambers 40 are connected to form an arc extinguishing chamber 4a. The side of the three arc extinguishing chambers 40 that is open in the same direction serves as the opening 41 of the arc extinguishing chamber 4a. A grid group is provided in each arc extinguishing chamber 40. Among them, the first grid group 42 is located in the middle arc extinguishing chamber 40, and the two second grid groups 43 are respectively arranged in the arc extinguishing chambers 40 on both sides. A connecting grid 44 or a transition grid group 45 is arranged between the first grid group 42 and the second grid group 43. In this embodiment, the multiple first arc extinguishing grid plates in the first grid group 42, the multiple second arc extinguishing grid plates in the second grid group 43, the connecting grid 44, and the transition grid group 45 can be specifically referred to the structure of the first arc extinguishing system 4.

[0087] In addition, a gas generating part 48, an arcing horn 46, a magnet 47, a flow guiding part 105, and an arc extinguishing part 49 can also be arranged in cooperation. The structure can be referred to the structure of the first arc extinguishing system 4.

[0088] It should be noted that when the contact mechanism 3 further includes an auxiliary contact 38, the assembly position for the auxiliary contact 38 can be referred to the assembly gap 42a in the first arc extinguishing system 4.

[0089] In this embodiment, the outer shell is an assembled structure. The outer shell includes a base 1a, a first support plate 1b, a second support plate 1c, and a cover 1d that are assembled in sequence along the first direction. A first assembly cavity is formed by the cover 1d and the second support plate 1c being spaced apart from each other. The operating mechanism 2 and the traction rod 20 are rotatably arranged in the first assembly cavity 101. Wiring cavities are formed at both ends of the first assembly cavity 101 for arranging the wiring assembly 6. Wiring holes and operating holes are correspondingly formed in the wiring cavities. The operating hole is adjacent to the wiring hole and is formed at a position near the end of the cover 1d. A driving hole is formed in the middle of the cover 1d. The operating member 21 connected to the operating mechanism 2 extends out of the outer shell through the driving hole. A linkage groove is formed in the middle of the second support plate. The connecting rod assembly 22 of the operating mechanism 2 passes through the linkage groove and is drivingly connected to the contact mechanism 3. The wiring assembly 6 includes a wiring terminal 61 and a connecting plate 62. One end of the connecting plate 62 is connected to the wiring terminal 61. The middle of the connecting plate 62 extends along the second support plate. The other end of the connecting plate 62 is connected to the contact mechanism 3. A thermal-magnetic tripping mechanism 5 is arranged between the operating mechanism 2 and one wiring assembly 6. The connecting plate 62 located between the thermal-magnetic tripping mechanism 5 and the adjacent wiring terminal 61 serves as a part of the thermal-magnetic tripping mechanism 5.

[0090] A second assembly cavity 102 is formed by the second support plate and the first support plate 1b being spaced apart from each other. The connecting plate 62 can be located in the first assembly cavity or the second assembly cavity. The thermal-magnetic tripping mechanism 5 can be assembled in the first assembly cavity. The thermal-magnetic tripping mechanism 5 includes a thermal release and a magnetic release. The bimetallic strip 51 of the thermal release and the armature 52 of the magnetic release are respectively matched with the traction rod 20. The contact mechanism 3 is arranged in the second assembly cavity. The contact mechanism 3 and the operating mechanism 2 are respectively arranged in two different stacked assembly cavities, which is conducive to forming a modular structure and facilitating assembly. The two moving contact assemblies are respectively connected to the connecting plate 62 through flexible connections. A blocking portion 1c1 is arranged on the side of the second support plate 1c facing the contact mechanism 3. The blocking portion 1c1 separates the two moving contact assemblies of the contact mechanism 3 and is used to cooperate with restricting the swinging height of the moving contact assemblies in the first direction. The blocking portion 1c1 can be fixedly arranged on the second support plate 1c alone or integrally formed by the second support plate 1c. Each moving contact assembly is connected to a connecting plate 62 through a flexible connection. One of the moving contact assemblies is drivingly connected to the connecting rod assembly 22 passing through the linkage hole. A first avoidance groove is formed in the middle of the first support plate 1b. The moving contact assembly passes through the first avoidance groove and rotates for opening and closing in the third assembly cavity formed by the cooperation of the base 1a and the first support plate 1b.

[0091] Preferably, an arc extinguishing system 4 is provided in the third assembly cavity, that is, all the arc extinguishing chambers 40 of the arc extinguishing system 4 are arranged in the third assembly cavity. The opening 41 of the arc extinguishing cavity 4a faces the contact mechanism 3. Each exhaust port 104 is covered with an arc extinguishing member 49. The guiding portion 105 protrudes from the side of the base 1a facing the first support plate 1b. The guiding inclined surface 1051 is formed by the base 1a near the exhaust port 104. In addition, the magnet 47 cooperating with the arc extinguishing cavity 4a can be arranged on the first support plate 1b. The two magnets 47 are arranged at intervals opposite to each other in the second direction and correspond to the opposite sides of the first avoidance groove.

[0092] In addition, partitions can be provided in the second assembly cavity and the third assembly cavity. The partitions divide the spaces of the second assembly cavity and the third assembly cavity 1 in the third direction for assembling the contact mechanisms 3 and the arc extinguishing systems 4 of different conductive systems. A partition is provided in the base 1a to separate the arc extinguishing systems 4 of adjacent two conductive systems.

[0093] It should be noted that in the description of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which it is usually placed during use. It is only for the convenience of description and does not indicate that the device or element referred to must have a specific orientation. Therefore, it cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating relative importance.

[0094] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as belonging to the protection scope of the present invention.

Claims

1. An arc extinguishing system, comprising an arc extinguishing chamber (4a), wherein the arc extinguishing chamber (4a) is provided with an opening (41), characterized in that: A plurality of arc-extinguishing grids are arranged in a spaced relationship within the arc-extinguishing cavity (4a), and the plurality of arc-extinguishing grids are divided into three grid groups, one of which is spaced and opposite to the opening (41), and the other two grid groups are arranged along opposite sides of the opening (41), so that the three grid groups are connected to form a U-shaped structure corresponding to the opening (41).

2. The arc extinguishing system (4) according to claim 1, characterized in that: The grid plate group opposite to the opening (41) is a first grid plate group (42), a plurality of arc-extinguishing grid plates of the first grid plate group (42) are first arc-extinguishing grid plates, a first arc-extinguishing gap is formed between two adjacent first arc-extinguishing grid plates, and one end of the first arc-extinguishing gap is opposite to the opening (41); The grid plate group arranged along one side of the opening (41) is a second grid plate group (43), a plurality of arc-extinguishing grid plates of the second grid plate group (43) are second arc-extinguishing grid plates, a second arc-extinguishing gap is formed between two adjacent second arc-extinguishing grid plates, one end of the second arc-extinguishing gap is opposite to the first grid plate group (42), so that the plurality of arc-extinguishing grid plates in the arc-extinguishing cavity (4a) are in a U-shaped structure as a whole.

3. The arc extinguishing system according to claim 2, characterized in that: The included angle between the extending direction of the first arc-extinguishing grid and the first direction is in the range of 0-20°, the included angle between the extending direction of the second arc-extinguishing grid and the second direction is in the range of 0-30°, and the first direction is perpendicular to the second direction.

4. The arc extinguishing system according to claim 2, characterized in that: The first grid plate group (42) is provided with a first arc extinguishing groove, and each second grid plate group (43) is provided with a second arc extinguishing groove, the first arc extinguishing groove is connected between two second arc extinguishing grooves, the groove line of the first arc extinguishing groove is arranged parallel to the second direction, the angle between the groove line of the second arc extinguishing groove and the first direction is in the range of 0 to 30 degrees, and the first direction is perpendicular to the second direction.

5. The arc extinguishing system according to claim 1, characterized in that: A connecting grid (44) is connected between two adjacent grid groups, and the middle of the connecting grid (44) is bent so that two ends of the connecting grid (44) are respectively spaced and opposite to the arc extinguishing grids of the adjacent grid groups.

6. The arc extinguishing system according to claim 5, characterized in that: The connecting grid (44) is provided with a connecting groove, and both ends of the connecting groove are respectively connected to the arc extinguishing grooves of two adjacent grid groups.

7. The arc extinguishing system according to claim 1, characterized in that: A transition grid plate group (45) is connected between two adjacent grid plate groups, and the transition grid plate group (45) includes a plurality of transition grid plates arranged at intervals.

8. The arc extinguishing system according to any one of claims 1 to 7, characterized in that: A contact mechanism (3) is provided on one side of the arc extinguishing chamber (4a), and the contact mechanism (3) comprises two movable contact assemblies rotatably assembled side by side, and the opening (41) allows the two movable contact assemblies to extend into the arc extinguishing chamber (4a), and the two movable contact assemblies contact or separate in an arc extinguishing area surrounded by three grid plate assemblies.

9. The arc extinguishing system according to claim 1, characterized in that: It also comprises at least one arc extinguishing chamber (40), and the inner space of each arc extinguishing chamber (40) is provided with at least one grid plate group as at least a part of the arc extinguishing cavity (4a).

10. A circuit breaker, including a housing, characterized in that: The arc extinguishing system (4) comprises two arc extinguishing chambers (40) arranged side by side, each arc extinguishing chamber (40) is provided with at least one grid plate group, the interiors of the two arc extinguishing chambers (40) are interconnected to form an arc extinguishing cavity (4a), an opening (41) is provided on the same side of the two arc extinguishing chambers (40), a grid plate group opposite to the opening (41) is divided into two sub-grid plate groups (421), and the two sub-grid plate groups (421) are respectively provided with Placed in two arc extinguishing chambers (40), an assembly gap (42a) is left between two grid plate groups (421), and a contact mechanism (3) is arranged on one side of the arc extinguishing chamber (4a). The contact mechanism (3) includes two movable contact assemblies rotatably assembled side by side. The contact mechanism (3) also includes an auxiliary contact (38). The auxiliary contact (38) is assembled in the assembly gap (42a), and the two movable contact assemblies are respectively in contact with or separated from the opposite sides of the auxiliary contact (38).

Images