Arc extinguishing system and miniature circuit breaker

Abstract

An arc extinguishing system and a miniature circuit breaker comprise an arc extinguishing chamber composed of a plurality of arc extinguishing grid sheets, and are characterized by further comprising an arc striking chamber, the arc striking chamber is located between a contact system and the arc extinguishing chamber, and the arc striking chamber comprises two flash barriers arranged oppositely and an isolation structure arranged between the two flash barriers. The isolation structure divides the arc ignition chamber into an upper arc ignition area A and a lower arc ignition area A. The upper arc ignition area A is located on the side, close to the contact system, of the lower arc ignition area A. The arc ignition chamber is divided into the upper arc ignition area and the lower arc ignition area through the isolation structure, and then electric arcs are guided to the top and the bottom of the arc extinguish chamber through the first arc ignition structure and the second arc ignition structure respectively. The arc extinguishing device has the advantages that arc energy concentration is avoided, arc extinguishing efficiency is remarkably improved, the upper arc striking area and the lower arc striking area are clear in division of labor, arc striking parts do not need to be additionally arranged, space utilization rate is higher, and the arc extinguishing device is compact in structure and small in size and is particularly suitable for high-efficiency breaking requirements of miniature circuit breakers.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical appliances, specifically to an arc extinguishing system and a miniature circuit breaker. Background Technology

[0002] Miniature circuit breakers primarily function as overload and short-circuit protection devices in circuit systems, with breaking capacity being one of the key performance indicators. A miniature circuit breaker mainly consists of a casing, operating mechanism, thermal tripping system, magnetic tripping system, and arc-extinguishing system. The magnetic tripping system is a crucial component, typically composed of a terminal block, coil, arc angle, stationary contacts, and core assembly.

[0003] Due to space constraints, miniature circuit breakers have limited breaking current capacity. If the arc cannot be completely extinguished within the arc-extinguishing system after a large current interruption, the product will be damaged and unusable. Furthermore, the arc angle primarily serves to conduct electricity and initiate arcing; however, a single material for the arc angle cannot simultaneously provide both good conductivity and arc-initiating performance. Therefore, it requires the use of other components such as brackets and inverted magnetic plates. This not only wastes metal materials but also increases the difficulty of manufacturing the components. Utility Model Content

[0004] The purpose of this invention is to overcome at least one defect of the prior art and provide an arc extinguishing system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An arc-extinguishing system includes an arc-extinguishing chamber composed of a plurality of arc-extinguishing grid plates, characterized in that it further includes an arc-initiating chamber located between a contact system and the arc-extinguishing chamber. The arc-initiating chamber includes two opposing arc-blocking plates and an isolation structure disposed between the two arc-blocking plates.

[0007] The isolation structure divides the arc-starting chamber into an upper arc-starting area and a lower arc-starting area, with the upper arc-starting area located on the side of the lower arc-starting area closer to the contact system.

[0008] The upper arc-starting area is connected to the top of the arc-extinguishing chamber and is provided with a first arc-starting structure, which is used to guide the electric arc into the top of the arc-extinguishing chamber.

[0009] The lower arc-starting area is connected to the bottom of the arc-extinguishing chamber and is provided with a second arc-starting structure, which is used to guide the electric arc into the bottom of the arc-extinguishing chamber.

[0010] Preferably, the isolation structure includes at least two baffles, with an arc-initiating channel formed between the two baffles. The arc-initiating channel communicates with the middle part of the arc-extinguishing chamber and connects between the upper arc-initiating area and the lower arc-initiating area.

[0011] Preferably, the cross-sectional area of ​​the arc-initiating channel is smaller than the cross-sectional area of ​​the upper arc-initiating region and smaller than the cross-sectional area of ​​the lower arc-initiating region.

[0012] Preferably, the isolation structure includes two baffles, which are arranged in parallel and spaced apart, forming the arc-inducing channel between the sides of the two baffles. One end of the baffle is fixed to one of the arc-isolating plates, and the other end is arranged opposite to the other arc-isolating plate to form a turning channel. The arc-inducing channel and the turning channels on both sides form a Z-shaped channel, and are connected to the upper arc-inducing area and the lower arc-inducing area respectively through the turning channels on both sides.

[0013] Preferably, it includes three or more baffles, which are alternately connected to two arc-blocking plates to form multiple parallel arc-initiating channels. The turning channels formed between the two outer baffles and the non-connected arc-blocking plates are respectively connected to the upper arc-initiating area and the lower arc-initiating area. The turning channel formed between at least one baffle in the middle and the non-connected arc-blocking plate is connected between two adjacent arc-initiating channels.

[0014] Preferably, the width W and length L of the arc-initiating channel are equal.

[0015] Preferably, the arc-starting chamber includes an arc-generating zone and an arc-starting zone located between the arc-generating zone and the arc-extinguishing chamber. The contact system includes a stationary contact and a moving contact. The stationary contact is located at one end of the top of the arc-generating zone, and the moving contact is located at the other end of the top of the arc-generating zone. The moving contact passes through the arc-generating zone and contacts and separates from the stationary contact. The isolation structure is provided in the arc-starting zone to divide the arc-starting zone into an upper arc-starting zone and a lower arc-starting zone.

[0016] Preferably, the second arc-inducing structure includes an arc-inducing piece, which is obliquely disposed on the side of the lower arc-inducing area away from the upper arc-inducing area. The first end of the arc-inducing piece extends to the side of the arc-generating area away from the upper arc-inducing area and is connected to the thermal trip unit.

[0017] Preferably, the two arc-blocking plates are provided with a first arc-initiating groove on their opposite sides. The first arc-initiating groove is inclinedly disposed between the baffle and the arc-initiating plate. One end of the first arc-initiating groove extends to the arc-extinguishing chamber, and the other end extends to the arc-generating area. The arc-generating area is provided with a second arc-initiating groove that is inclinedly connected to the first arc-initiating groove. The second arc-initiating groove extends to the contact system.

[0018] Preferably, it also includes a magnetic trip unit, which includes a coil and an iron core. The coil is connected to a contact plate, and the contact plate is provided with a stationary contact. The end of the contact plate away from the coil is provided with a first arc-inducing structure.

[0019] Preferably, the contact plate includes:

[0020] A conductive part, the resistance of which is less than that of a magnetic part, the conductive part is connected to a coil, and the stationary contact is disposed on the conductive part;

[0021] The magnetically conductive part has a higher permeability than the conductive part, and the magnetically conductive part extends into the arc-extinguishing chamber.

[0022] Preferably, the conductive part includes a first conductive segment, and a second conductive segment and a third conductive segment that are bent and connected to both ends of the first conductive segment respectively. The second conductive segment is connected to the coil, and the third conductive segment is arc-shaped and connected to the magnetic conductive part. The magnetic conductive part includes a first magnetic conductive segment located at the top of the arc-extinguishing chamber, and a second magnetic conductive segment that is inclinedly connected between the first magnetic conductive segment and the third conductive segment. The third conductive segment, the first magnetic conductive segment, and the second magnetic conductive segment constitute a first magnetic conductive structure.

[0023] The arc extinguishing system of this embodiment divides the arc-ignition chamber into an upper arc-ignition area and a lower arc-ignition area through an isolation structure. The first arc-ignition structure and the second arc-ignition structure guide the arc to the top and bottom of the arc-extinguishing chamber, respectively, to avoid the concentration of arc energy and significantly improve the arc extinguishing efficiency. Moreover, the upper arc-ignition area and the lower arc-ignition area have clear division of labor, eliminating the need for additional arc-ignition components, resulting in higher space utilization and a compact structure with small size.

[0024] In addition, the electric arc can move across the arc-starting channel from the upper arc-starting area to the lower arc-starting area, preventing the electric arc from accumulating in the upper arc-starting area, attracting more electric arcs to the arc-starting channel and the lower arc-starting area, and at the same time lengthening the electric arc.

[0025] In addition, by reducing the cross-sectional area of ​​the arc-ignition channel to create a pressure effect, the flow velocity in the arc-ignition channel can be increased, attracting the electric arc from the upper arc-ignition area to the arc-ignition channel and the lower arc-ignition area, while simultaneously blowing the electric arc rapidly to the center of the arc-extinguishing chamber.

[0026] Furthermore, the two turning channels, each connected to the arc-starting channel, form a Z-shaped channel. The Z-shaped channel has a Z-shaped cross-section perpendicular to the length of the circuit breaker, forcing the arc to turn as it moves from the upper arc-starting zone to the lower arc-starting zone, further lengthening the path and dispersing energy. Preferably, the arc-starting channel...

[0027] Furthermore, by increasing the number of baffles to form a multi-stage channel with multiple turns, the path of arc movement can be further increased, the arc lengthened, and the arc resistance increased.

[0028] This embodiment also provides a miniature circuit breaker, including the arc extinguishing system, which is particularly suitable for the high-efficiency breaking requirements of miniature circuit breakers. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the base of the shell and the internal structure of the base;

[0030] Figure 2 This is a schematic diagram of the structure of the shell cover and the arc-breaking plate in the cover;

[0031] Figure 3This is a first cross-sectional view of the arc-ignition chamber, showing the direction in which the electric arc moves from the arc-ignition chamber to the arc-extinguishing chamber;

[0032] Figure 4 This is a second cross-sectional view of the arc-starting chamber, showing its internal structure.

[0033] Figure 5 This is the third cross-sectional view of the arc-ignition chamber, showing the direction of arc movement inside the chamber;

[0034] Figure 6 This is a schematic diagram of the arc-blocking plate;

[0035] Figure 7 This is the first embodiment of the isolation structure, which has two baffles;

[0036] Figure 8 This is a second embodiment of the isolation structure, with three baffles;

[0037] Figure 9 This is another embodiment of the isolation structure, in which the baffle is trapezoidal;

[0038] Figure 10 This is another embodiment of the isolation structure, in which the baffle is semi-circular;

[0039] Figure 11 This is a schematic diagram of the contact plate structure;

[0040] In the picture:

[0041] Detailed Implementation

[0042] The specific implementation of the arc-extinguishing system of this utility model is further described below with reference to the accompanying drawings. The arc-extinguishing system of this utility model is not limited to the description of the following embodiments.

[0043] The miniature circuit breaker of this embodiment includes a housing 1 and an operating mechanism 2, a contact system, a thermal tripping system 3, a magnetic tripping system 4, and an arc extinguishing system respectively disposed in the housing 1. The contact system includes a stationary contact 51 and a moving contact 52 that constitute part of the main circuit. Current is turned on and off by the contact and separation of the moving contact 52 and the stationary contact 51. The handle is connected to the operating mechanism 2, and the operating mechanism 2 is connected to the moving contact 52. The operating mechanism 2 is driven by the handle or an electric mechanism to realize the opening and closing control. When closing, the moving contact 52 and the stationary contact 51 close to form a conductive path. When opening, the contacts separate to cut off the current.

[0044] When the circuit is overloaded, the bimetallic strip of the thermal trip system 3 bends due to heat, pushing the trip lever to trigger the operating mechanism 2 to trip. When the circuit is short-circuited, the coil 41 of the magnetic trip system 4 induces a large current to generate a strong magnetic field, driving the iron core 42 to strike the trip lever and trigger the operating mechanism 2 to trip, achieving rapid disconnection. The electric arc generated at the moment of disconnection is extinguished by the arc extinguishing system, which ensures safe disconnection and prevents arc reignition or equipment damage.

[0045] like Figure 1-5 As shown, the arc extinguishing system of this embodiment includes:

[0046] The arc-extinguishing chamber 6 includes multiple arc-extinguishing grids 61, which are used to divide and cool the electric arc, so that the electric arc is extinguished quickly.

[0047] The arc-starting chamber 7 includes two arc-blocking plates 70 arranged opposite each other, and an isolation structure 8 disposed between the two arc-blocking plates 70. The isolation structure 8 divides the arc-starting chamber 7 into an upper arc-starting area A1 and a lower arc-starting area A2. The upper arc-starting area A1 is located on the side of the lower arc-starting area A2 closer to the contact system.

[0048] The upper arc-starting area A1 is connected to the top of the arc-extinguishing chamber 6 and is provided with a first arc-starting structure 71, which is used to guide the electric arc into the top of the arc-extinguishing chamber 6.

[0049] The lower arc-starting area A2 is connected to the bottom of the arc-extinguishing chamber 6 and is provided with a second arc-starting structure 72, which is used to guide the electric arc into the bottom of the arc-extinguishing chamber 6.

[0050] The arc extinguishing system of this embodiment divides the arc-igniting chamber 7 into an upper arc-igniting area A1 and a lower arc-igniting area A2 through an isolation structure 8. The first arc-igniting structure 71 and the second arc-igniting structure 72 guide the arc to the top and bottom of the arc-extinguishing chamber 6, respectively, to avoid the concentration of arc energy and significantly improve the arc extinguishing efficiency. Moreover, the upper arc-igniting area A1 and the lower arc-igniting area A2 have a clear division of labor, eliminating the need for additional arc-igniting components, resulting in higher space utilization and a compact structure with a small size.

[0051] like Figure 1 As shown, the arc-starting chamber 7 includes an arc-generating zone B and an arc-starting zone located between the arc-generating zone B and the arc-extinguishing chamber 6. The stationary contact 51 is located at one end of the top of the arc-generating zone B, and the moving contact 52 is located at the other end of the top of the arc-generating zone B. The moving contact 52 passes through the arc-generating zone B and contacts and separates from the stationary contact 51. The isolation structure 8 is located in the arc-starting zone and is used to divide the arc-starting zone into an upper arc-starting zone A1 and a lower arc-starting zone A2. The isolation structure 8 is parallel to the bottom sidewall of the housing 1 and is substantially parallel to the arc-extinguishing grid plate 61.

[0052] like Figure 3-5As shown, the isolation structure 8 includes at least two baffles 81, forming an arc-starting channel 82 between the two baffles 81. The arc-starting channel 82 communicates with the middle of the arc-extinguishing chamber 6 and connects between the upper arc-starting area A1 and the lower arc-starting area A2. The arc-starting channel 82 is connected to both the upper arc-starting area A1 and the lower arc-starting area A2, allowing the electric arc to move from the upper arc-starting area A1 to the lower arc-starting area A2, preventing the electric arc from accumulating in the upper arc-starting area A1 and attracting more electric arc to the arc-starting channel 82 and the lower arc-starting area A2, while also lengthening the electric arc. Furthermore, the isolation structure 8 can further divide the electric arc into three segments, which, combined with the upper arc-starting area A1 and the lower arc-starting area A2, guide the three segments of the arc to the top, middle, and bottom of the arc-extinguishing chamber 6, respectively, thus effectively utilizing the entire arc-extinguishing chamber 6.

[0053] like Figure 3 As shown, the cross-sectional area of ​​the arc-initiating channel 82 is smaller than that of the upper arc-initiating region A1 and smaller than that of the lower arc-initiating region A2. By reducing the cross-sectional area of ​​the arc-initiating channel 82 to create a pressure effect, the flow velocity in the arc-initiating channel 82 can be increased, attracting the arc from the upper arc-initiating region A1 to the arc-initiating channel 82 and the lower arc-initiating region A2, while simultaneously blowing the arc rapidly to the middle of the arc-extinguishing chamber 6. Of course, the cross-sectional area of ​​the arc-initiating channel 82 can also be similar to that of the upper arc-initiating region A1. When the cross-sectional areas are similar, the effect is improved only by arc segmentation.

[0054] like Figure 3-7 The first embodiment of the isolation structure 8 is shown. This embodiment includes two flat baffles 81 corresponding to two arc-blocking plates 70 respectively. The two baffles 81 are arranged in parallel and spaced apart. An arc-inducing channel 82 is formed between the two baffles 81 and is arranged parallel to the length direction of the circuit breaker. One end of the two baffles 81 is connected to the corresponding arc-blocking plate 70 respectively. The baffles 81 are basically perpendicular to the arc-blocking plate 70. The other end of the two baffles 81 is arranged at intervals with another arc-blocking plate 70 and forms a turning channel 83 that communicates with the arc-inducing channel 82. The two turning channels 83 are connected to the arc-inducing channel 82 on both sides along the width direction of the circuit breaker. The turning channels 83 are arranged parallel to the height direction of the circuit breaker.

[0055] The two turning channels 83, connected to the arc-starting channel 82, form a Z-shaped channel. The cross-section of the Z-shaped channel, perpendicular to the length of the circuit breaker, is Z-shaped, forcing the arc to turn as it moves from the upper arc-starting zone A1 to the lower arc-starting zone A2, further lengthening the path and dispersing energy. Preferably, the width W (distance between the sides of the two baffles 81) and the length L (distance between the ends of the two baffles 81) of the arc-starting channel 82 are equal, and the selectable range is 0.5-2mm, preferably 1mm.

[0056] It is understood that the baffle 81 of the isolation structure 8 can also be an integral structure, and then installed between the two arc-blocking plates 70 by snap-fit ​​or welding, or fixedly installed on one of the arc-blocking plates 70 and extending to the other baffle. The arc-initiating channel 82 and the turning channel 83 can be processed on the isolation structure 8, or the arc-initiating channel 82 or the turning channel 83 can be omitted.

[0057] In addition, the two baffles 81 can also be arranged opposite to each other, forming an arc-initiating channel 82 between the two baffles 81. The arc-initiating channel 82 directly connects the arc-initiating channel 82 between the upper arc-initiating area A1 and the lower arc-initiating area A2 and cancels the turning channel 83.

[0058] like Figure 8 A second embodiment of the isolation structure 8 is shown. The isolation structure 8 includes three or more baffles 81, which are alternately connected to two arc-blocking plates 70 to form multiple parallel arc-initiating channels 82. The turning channels 83 formed between the two outer baffles 81 and the non-connected arc-blocking plates 70 are respectively connected to the upper arc-initiating area A1 and the lower arc-initiating area A2. The turning channels 83 formed between at least one baffle 81 in the middle and the non-connected arc-blocking plates 70 are connected between two adjacent arc-initiating channels 82. By increasing the number of baffles 81 to form a multi-level channel with multiple turns, the path of arc movement can be further increased, the arc can be lengthened, and the resistance of the arc can be increased.

[0059] Specifically, when there are three baffles 81, the three baffles 81 are respectively the first baffle, the second baffle, and the third baffle, and the two arc-blocking plates 70 are respectively the left arc-blocking plate and the right arc-blocking plate; one end of the first baffle and the third baffle are fixed to the left arc-blocking plate, and the other end is arranged opposite to the right arc-blocking plate to form the first turning channel and the third turning channel, respectively; one end of the second baffle is fixed to the right arc-blocking plate, and the other end is arranged opposite to the left arc-blocking plate to form the second turning channel; the second baffle and the first baffle and the third baffle on both sides form the upper arc-drawing channel and the lower arc-drawing channel, respectively, and the second turning channel connects the upper arc-drawing channel and the lower arc-drawing channel; the upper arc-drawing channel is connected to the upper arc-drawing area A1 through the first turning channel, and the lower arc-drawing channel is connected to the lower arc-drawing area A2 through the second turning channel. Of course, the number of baffles 81 can also be expanded to four, five or more.

[0060] Understandably, baffle 81 can also be non-flat:

[0061] like Figure 9 The trapezoidal baffle 81 shown has its wide end fixed to one of the arc-blocking plates 70, and its narrow end opposite to the other arc-blocking plate 70 to form a turning channel 83. An arc-inducing channel 82 is formed between the inclined sides of two adjacent baffles 81, which is inclined to the height direction of the circuit breaker.

[0062] like Figure 10 The semi-circular baffle 81 shown is fixed to one of the arc-blocking plates 70. The arc-shaped surface is arranged opposite to the other arc-blocking plate 70 to form a turning channel 83. An arc-shaped arc-inducing channel 82 is formed between the arc-shaped surfaces of two adjacent baffles 81.

[0063] like Figure 1 As shown, the first arc-inducing structure 71 is integrated into the magnetic trip unit, which includes a coil 41 and an iron core 42. The coil 41 is wound around the outside of the iron core 42. When a short-circuit current passes through the coil 41, a magnetic field is generated to drive the iron core 42 to trigger the operating mechanism 2 to unlock and achieve rapid disconnection. The two ends of the coil 41 are connected to the terminal block 43 and the contact plate 44, respectively. The contact plate 44 is provided with a stationary contact 51. The end of the contact plate 44 away from the coil 41 is provided with the first arc-inducing structure 71. The first arc-inducing structure 71 is bent and passes through the upper arc-inducing area A1 and extends into the arc-extinguishing chamber 6.

[0064] The electric arc generated during disconnection can be transferred from the stationary contact 51 to the first arc-initiating structure 71, and then guided to the arc-extinguishing chamber 6 through the first arc-initiating structure 71. The contact plate 44 not only forms part of the main circuit with the magnetic trip unit, but can also participate in arc initiation, which can avoid occupying extra space and adapt to the space limitations of miniature circuit breakers.

[0065] like Figure 11 As shown, the contact plate 44 is a composite structure, comprising:

[0066] The conductive part 45 is made of a low-resistance material such as copper or copper alloy. The resistance of the conductive part 45 is less than that of the magnetic part. The conductive part 45 is connected to the coil 41. The stationary contact 51 is disposed on the conductive part 45.

[0067] The magnetically conductive part 46 is made of a high magnetic permeability material such as silicon steel or iron-nickel alloy. The magnetic permeability of the magnetically conductive part 46 is greater than that of the conductive part 45. The magnetically conductive part 46 extends into the arc-extinguishing chamber 6.

[0068] The conductive part 45 and the magnetic part 46 are connected by welding, riveting or material composite process. The low resistance of the conductive part 45 can reduce the loss of the main circuit, and the high permeability of the magnetic part 46 can enhance the arc driving force and improve the arc ignition effect.

[0069] In this embodiment, the conductive part 45 includes a first conductive segment 451, and a second conductive segment 452 and a third conductive segment 453 that are bent and connected to both ends of the first conductive segment 451, respectively. The second conductive segment 452 is connected to the coil 41, and the third conductive segment 453 is arc-shaped and connected to the magnetically conductive part 46. The magnetically conductive part 46 includes a first magnetically conductive segment 461 located at the top of the arc-extinguishing chamber 6, and a second magnetically conductive segment 462 that is inclined between the first magnetically conductive segment 461 and the third conductive segment 453. The third conductive segment 453, the first magnetically conductive segment 461 and the second magnetically conductive segment 462 constitute a first magnetically conductive structure.

[0070] The third conductive section 453 initially guides the arc to the upper arc-drawing area A1 to prevent the arc from stalling between the contacts. Then, the arc is quickly introduced into the arc-extinguishing chamber 6 through the first magnetically conductive section 461 and the second magnetically conductive section 462.

[0071] like Figure 1 As shown, the second arc-initiating structure 72 includes an arc-initiating piece 720. The arc-initiating piece 720 is inclinedly disposed on the side of the lower arc-initiating area A2 away from the upper arc-initiating area A1. The first end 721 of the arc-initiating piece 720 extends to the side of the arc-generating area B away from the upper arc-initiating area A1 and is connected to the thermal trip unit to fix the thermal trip unit. The second end 722 extends to the bottom of the arc-extinguishing chamber 6 to draw the arc to the bottom of the arc-extinguishing chamber 6.

[0072] like Figure 4 As shown, permanent magnet plates 73 are respectively provided on the opposite sides of the two arc-blocking plates 70. The permanent magnet plates 73 can generate a magnetic field to drive the electric arc to move towards the arc-extinguishing chamber 6.

[0073] The two arc-blocking plates 70 are respectively provided with a first arc-initiating groove 74 on their opposite sides. The first arc-initiating groove 74 is inclinedly disposed between the baffle 81 and the arc-initiating plate 720. One end of the first arc-initiating groove 74 extends to the arc-extinguishing chamber 6, and the other end extends to the arc-generating area B. The arc-generating area B is provided with a second arc-initiating groove 75 that is inclinedly connected to the first arc-initiating groove. The second arc-initiating groove 75 extends to the contact system. The arc-initiating groove can guide the arc to the arc-extinguishing chamber 6 and can also guide the gas flow, so that the arc can be moved towards the arc-extinguishing chamber 6 by the air flow.

[0074] The two arc-blocking plates 70 are provided with inclined sides 75 corresponding to the arc-initiating plate 720 on the side of the first arc-initiating groove 74 away from the baffle 81. The inclined sides 75 are at the same angle as the arc-initiating plate 720 and form a continuous space with the arc-initiating plate 720 to guide the movement of the electric arc.

[0075] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used during use. They are only for ease of description and do not indicate that the device or component referred to must have a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating relative importance.

[0076] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. An arc-extinguishing system, comprising an arc-extinguishing chamber (6) composed of a plurality of arc-extinguishing grid plates (61), characterized in that, It also includes an arc-starting chamber (7), which is located between the contact system and the arc-extinguishing chamber (6). The arc-starting chamber (7) includes two arc-blocking plates (70) arranged opposite to each other, and an isolation structure (8) arranged between the two arc-blocking plates (70). The isolation structure (8) divides the arc-starting chamber (7) into an upper arc-starting area (A1) and a lower arc-starting area (A2), wherein the upper arc-starting area (A1) is located on the side of the lower arc-starting area (A2) closer to the contact system; The upper arc-starting area (A1) is connected to the top of the arc-extinguishing chamber (6) and is provided with a first arc-starting structure (71), which is used to guide the electric arc into the top of the arc-extinguishing chamber (6); The lower arc-starting area (A2) is connected to the bottom of the arc-extinguishing chamber (6) and is provided with a second arc-starting structure (72), which is used to guide the electric arc into the bottom of the arc-extinguishing chamber (6).

2. The arc-extinguishing system according to claim 1, characterized in that, The isolation structure (8) includes at least two baffles (81), and an arc-initiating channel (82) is formed between the two baffles (81). The arc-initiating channel (82) is connected to the middle of the arc-extinguishing chamber (6) and is connected between the upper arc-initiating area (A1) and the lower arc-initiating area (A2).

3. The arc-extinguishing system according to claim 2, characterized in that, The cross-sectional area of ​​the arc-drawing channel (82) is smaller than the cross-sectional area of ​​the upper arc-drawing area (A1) and smaller than the cross-sectional area of ​​the lower arc-drawing area (A2).

4. The arc-extinguishing system according to claim 2, characterized in that, The isolation structure (8) includes two baffles (81) arranged in parallel and spaced apart, forming the arc-inducing channel (82) between the sides of the two baffles (81). One end of the baffle (81) is fixed to one of the arc-blocking plates (70), and the other end is arranged opposite to the other arc-blocking plate (70) to form a turning channel (83). The arc-inducing channel (82) and the turning channels (83) on both sides form a Z-shaped channel, and are connected to the upper arc-inducing area (A1) and the lower arc-inducing area (A2) respectively through the turning channels (83) on both sides.

5. The arc-extinguishing system according to claim 2, characterized in that, It includes three or more baffles (81), which are alternately connected to two arc-blocking plates (70) to form multiple parallel arc-initiating channels (82). The turning channel (83) formed between the two outer baffles (81) and the non-connected arc-blocking plates (70) is connected to the upper arc-initiating area (A1) and the lower arc-initiating area (A2) respectively. The turning channel (83) formed between at least one baffle (81) in the middle and the non-connected arc-blocking plates (70) is connected between two adjacent arc-initiating channels (82).

6. The arc-extinguishing system according to claim 4 or 5, characterized in that, The width W and length L of the arc-initiating channel (82) are equal.

7. The arc-extinguishing system according to claim 1, characterized in that, The arc-starting chamber (7) includes an arc-generating zone (B) and an arc-starting zone located between the arc-generating zone (B) and the arc-extinguishing chamber (6). The contact system includes a stationary contact (51) and a moving contact (52). The stationary contact (51) is located at one end of the top of the arc-generating zone (B), and the moving contact (52) is located at the other end of the top of the arc-generating zone (B). The moving contact (52) passes through the arc-generating zone (B) and contacts and separates from the stationary contact (51). The isolation structure (8) is located in the arc-starting zone and is used to divide the arc-starting zone into an upper arc-starting zone (A1) and a lower arc-starting zone (A2).

8. The arc-extinguishing system according to claim 7, characterized in that, The second arc-inducing structure (72) includes an arc-inducing piece (720), which is inclinedly disposed on the side of the lower arc-inducing area (A2) away from the upper arc-inducing area (A1). The first end (721) of the arc-inducing piece (720) extends to the side of the arc-generating area (B) away from the upper arc-inducing area (A1) and is connected to the thermal trip unit.

9. The arc extinguishing system according to claim 8, characterized in that, The two arc-blocking plates (70) are respectively provided with a first arc-initiating groove (74) on their opposite sides. The first arc-initiating groove (74) is inclinedly arranged between the baffle (81) and the arc-initiating plate (720). One end of the first arc-initiating groove (74) extends to the arc-extinguishing chamber (6) and the other end extends to the arc-generating area (B). The arc-generating area (B) is provided with a second arc-initiating groove (75) that is inclinedly connected to the first arc-initiating groove. The second arc-initiating groove (75) extends to the contact system.

10. The arc-extinguishing system according to claim 1, characterized in that, It also includes a magnetic trip unit, which includes a coil (41) and an iron core (42). The coil (41) is connected to a contact plate (44). The contact plate (44) is provided with a stationary contact (51). The end of the contact plate (44) away from the coil (41) is provided with a first arc-starting structure (71).

11. The arc-extinguishing system according to claim 10, characterized in that, The contact plate (44) includes: The conductive part (45) has a lower resistance than the magnetic part (46). The conductive part (45) is connected to the coil (41). The stationary contact (51) is disposed on the conductive part (45). The magnetic permeability of the magnetic permeable part (46) is greater than that of the conductive part (45), and the magnetic permeable part (46) extends into the arc-extinguishing chamber (6).

12. The arc-extinguishing system according to claim 11, characterized in that, The conductive part (45) includes a first conductive segment (451), and a second conductive segment (452) and a third conductive segment (453) that are bent and connected to both ends of the first conductive segment (451), respectively. The second conductive segment (452) is connected to the coil (41), and the third conductive segment (453) is arc-shaped and connected to the magnetic conductive part (46). The magnetic conductive part (46) includes a first magnetic conductive segment (461) located at the top of the arc-extinguishing chamber (6), and a second magnetic conductive segment (462) that is inclined between the first magnetic conductive segment (461) and the third conductive segment (453). The third conductive segment (453), the first magnetic conductive segment (461), and the second magnetic conductive segment (462) form a first magnetic conductive structure.

13. A miniature circuit breaker, characterized in that, Including the arc extinguishing system as described in any one of claims 1-12.

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