Arc extinguishing mechanism for circuit breaker and circuit breaker

Abstract

The utility model relates to an arc extinguishing mechanism for a circuit breaker and the circuit breaker. The arc extinguishing mechanism comprises a support which extends along a first direction and is provided with a first end and a second end which are opposite to each other in the first direction, and the support defines an accommodating cavity; the multiple grid pieces are arranged in the containing cavity at intervals in the first direction, and each grid piece extends in the second direction forming an angle with the first direction; the first arc guide plate extends from the first end of the support to the second end of the support, the first arc guide plate is provided with a first groove which is open back to the second end of the support, and the first groove is suitable for being connected into a loop from the static contact side of the circuit breaker; the second arc guide plate extends from the second end of the support to the first end of the support, the second arc guide plate is provided with a second groove which is opened back to the first end of the support, and the second groove is suitable for being connected into the loop from the moving contact side of the circuit breaker; wherein an accommodating space allowing a moving contact of the circuit breaker to move between the first groove and the second groove for opening or closing is defined between the first groove and the second groove.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit protection, in particular to an arc extinguishing mechanism for a circuit breaker and a circuit breaker. Background Art

[0002] Micro Circuit Breaker (MCB), also known as Miniature Circuit Breaker, is an important component of the power system. It can close, carry and disconnect current under normal circuit conditions, and can disconnect current within a specified time under abnormal circuit conditions (such as short circuit or overload), thereby effectively protecting other electrical appliances in the circuit.

[0003] The breaking capacity of fault current has always been an important performance evaluation index of miniature circuit breakers. Usually, an arc extinguishing chamber is set inside the miniature circuit breaker to extinguish the arc generated between the moving and static contacts during the opening period. As for the multi-level (for example, four-level) series DC circuit breaker products commonly seen in the market, the arc extinguishing chamber space utilization rate of the single-pole circuit breaker is very low, and there is a problem of poor breaking capacity. For DC high-voltage products such as miniature circuit breakers, the arc is easy to stagnate and burn the contacts under critical current.

[0004] Therefore, there is a certain demand in the industry for improving miniature circuit breakers to enhance their arc extinguishing capabilities. Utility Model Content

[0005] The utility model aims to provide an arc extinguishing mechanism for a circuit breaker, which can at least solve part of the above technical problems.

[0006] The utility model also aims to provide a circuit breaker using the improved arc extinguishing mechanism.

[0007] According to one aspect of the utility model, an arc extinguishing mechanism for a circuit breaker is provided, the arc extinguishing mechanism comprising: a bracket extending along a first direction and having a first end and a second end opposite to each other in the first direction, the bracket defining a housing cavity; a plurality of grids arranged in the housing cavity at intervals along the first direction, wherein each grid extends along a second direction at an angle to the first direction; a first arc guide plate extending from the first end of the bracket toward the second end of the bracket, the first arc guide plate being configured with a first groove open to the second end of the bracket, wherein the first groove is suitable for accessing a circuit from the static contact side of the circuit breaker; a second arc guide plate extending from the second end of the bracket toward the first end of the bracket, the second arc guide plate being configured with a second groove open to the first end of the bracket, wherein the second groove is suitable for accessing a circuit from the moving contact side of the circuit breaker; wherein an accommodation space is defined between the first groove and the second groove for allowing the moving contact of the circuit breaker to move therebetween for opening or closing the circuit.

[0008] According to the arc extinguishing mechanism provided in this embodiment, the bracket is suitable for being arranged in the housing of the circuit breaker along the first direction (in the sense of this application, the first direction is substantially consistent with the lateral direction of the housing of the circuit breaker), and a plurality of grids are arranged along the lateral direction of the housing, thereby making full use of the internal space of the housing of the single-pole circuit breaker to arrange more grids, so as to increase the heat capacity and arc voltage of the arc extinguishing chamber, and improve the breaking capacity of the high-voltage DC circuit breaker. The first slot is connected to the circuit from the static contact side of the circuit breaker, and the second slot is connected to the circuit from the moving contact side of the circuit breaker. The circuit current constructed by the first slot and the second slot forms magnetic blow in the range involved by the static contact and the moving contact, so as to prevent the arc from forming back breakdown between the contacts.

[0009] In some embodiments, the arc extinguishing mechanism further comprises a first magnetizing member or a permanent magnet disposed in the first slot. Arranging the first magnetizing member or the permanent magnet in the loop of the first slot can enhance the magnetic blowing force of the circuit breaker on the arc under low current.

[0010] In some embodiments, the arc extinguishing mechanism further comprises a second magnetizing member or a permanent magnet disposed in the second slot. Arranging the second magnetizing member or the permanent magnet in the loop of the second slot can enhance the magnetic blowing force of the circuit breaker on the arc under low current.

[0011] In some embodiments, an open area of ​​the first groove facing away from the second groove is larger than an open area of ​​the second groove facing away from the first groove.

[0012] In some embodiments, the first slot is closer to a middle portion of the bracket between the first end and the second end than the second slot.

[0013] In some embodiments, a side of the first slot facing the second slot has a stationary contact engagement area.

[0014] In some embodiments, the plurality of grid sheets include a plurality of first grid sheets and a plurality of second grid sheets, wherein the first grid sheets and the second grid sheets have different lengths in the second direction, and the plurality of first grid sheets and the plurality of second grid sheets are alternately arranged along the first direction.

[0015] In some embodiments, the grid includes: a main body; a pair of legs extending from the main body along the second direction, an arc-starting groove is formed between the pair of legs, and the arc-starting groove includes a first section close to the main body and a second section away from the main body, wherein in the first section, the spacing between the pair of legs is constant, and in the second section, the spacing between the pair of legs increases gradually along the direction away from the body.

[0016] According to another aspect of the utility model, a circuit breaker is provided, comprising: a housing having a transverse direction and a longitudinal direction; a handle pivotally mounted to the housing; a contact mechanism comprising a stationary contact and a movable moving contact;

[0017] An operating mechanism, comprising a tripping member and a lock connected to the handle, wherein the tripping member can be locked with the lock to keep the moving contact in a state of engagement with the static contact, and the tripping member can be unlocked with the lock to allow the moving contact to separate from the static contact; a tripping mechanism, mounted on the housing and capable of driving the tripping member to unlock the lock; an arc extinguishing mechanism, which is the aforementioned arc extinguishing mechanism, wherein the arc extinguishing mechanism and the handle are arranged on opposite sides of the housing along the longitudinal direction, the static contact is engaged with the side of the first slot of the first arc guide plate facing the second slot of the second arc guide plate, and the multiple grid plates are arranged at intervals along the transverse direction of the housing, and each grid plate extends along the longitudinal direction of the housing.

[0018] In some embodiments, the trip mechanism includes a bimetallic strip connected to the moving contact, the bimetallic strip can deform in response to preset conditions to drive the tripping member to unlock the lock, wherein the second groove of the second arc guide plate is engaged with the bimetallic strip.

[0019] Some of the other features and advantages of the present invention will be apparent to those skilled in the art after reading this application, and the other parts will be described in the following specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 is a schematic diagram of the internal structure of a circuit breaker according to an embodiment of the utility model;

[0022] Figure 2 is a schematic diagram of the internal structure of a circuit breaker according to an embodiment of the utility model, wherein the bracket is omitted to expose the entire grid;

[0023] Figure 3 It is a schematic diagram of an arc extinguishing mechanism and moving and static contacts according to an embodiment of the utility model;

[0024] Figure 4 is a schematic diagram of a first arc guide plate according to an embodiment of the utility model;

[0025] Figure 5 is a schematic diagram of a second arc guide plate according to an embodiment of the utility model;

[0026] Figure 6 is a schematic diagram of a bracket of an arc extinguishing mechanism according to an embodiment of the utility model;

[0027] Figure 7 It is a schematic diagram of a grid piece of an arc extinguishing mechanism according to an embodiment of the utility model.

[0028] Description of reference numerals:

[0029] 1-circuit breaker; 11-housing; 111-export; 12-first terminal; 13-second terminal; 14-handle; 15-connecting rod; 16-operating mechanism; 17-contact mechanism; 171-static contact; 172-moving contact; 18-bimetallic strip; 19-electromagnetic tripping mechanism; 2-arc extinguishing mechanism; 3-bracket; 31-side wall; 311-installation opening; 32-bottom wall; 321-air outlet; 322-baffle; 323-protrusion; 33-accommodating cavity ;34-first end;35-second end;4-grid;41-body;42-leg;421-extended end;44-arc-starting groove;441-first section;442-second section;45-mounting protrusion;5-first arc guide plate;51-first groove;52-first open area;6-second arc guide plate;61-second groove;62-second open area;7-gas-generating plate;8-first magnetizing member or permanent magnet;9-second magnetizing member or permanent magnet;X-transverse;Y-longitudinal DETAILED DESCRIPTION

[0030] Now, with reference to the accompanying drawings, the schematic scheme of the circuit breaker and the arc extinguishing mechanism disclosed by the utility model is described in detail. Although the drawings are provided to present some embodiments of the utility model, the drawings do not have to be drawn according to the dimensions of the specific implementation scheme, and certain features may be enlarged, removed or partially cut to better illustrate and explain the disclosure of the utility model. Some components in the drawings can be adjusted in position according to actual needs without affecting the technical effect. The phrase "in the drawings" or similar terms appearing in the specification do not necessarily refer to all drawings or examples.

[0031] Certain directional terms used to describe the drawings below, such as "inside", "outside", "above", "below" and other directional terms, will be understood to have their normal meanings and refer to those directions involved when the drawings are normally viewed. Unless otherwise specified, the directional terms described in this specification are basically in accordance with the conventional directions understood by those skilled in the art.

[0032] The terms "first", "first", "second", "second" and the like used in the present invention do not indicate any order, quantity or importance, but are used to distinguish one component from other components.

[0033] Figure 1 A circuit breaker 1 according to an embodiment of the utility model is shown, and the circuit breaker 1 can be any miniature circuit breaker (MCB) requiring short-circuit protection, a residual current operated circuit breaker (RCBO) with overcurrent protection, and an MCB product used in combination with a residual current operated circuit breaker (RCD).

[0034] like Figure 1 and Figure 2 As shown, the circuit breaker 1 includes a housing 11 defining an internal space for accommodating an operating mechanism 16, a contact mechanism 17, an arc extinguishing mechanism 2, a tripping mechanism, a circuit, and the like. Figure 1 and Figure 2 The structure and layout inside the housing 2 are generally shown. As shown in the figure, the housing 2 has a lateral direction X and a longitudinal direction Y that are substantially perpendicular to each other, the first terminal 12 and the second terminal 13 are arranged at opposite ends of the housing 2 along the lateral direction X, and the operating mechanism 16, the contact mechanism 17, the arc extinguishing mechanism 2 and the opening mechanism are arranged between the first terminal 12 and the second terminal 13. The first terminal 12 is connected to the static contact 171, the second terminal 13 is connected to the moving contact 172, and the moving contact 17 is pivotally installed in the internal space of the housing 11 so as to engage with the static contact 171 to achieve closing, or separate from the static contact 171 to achieve opening. In this way, the circuit breaker 1 is connected to the circuit.

[0035] The handle 14 is pivotally connected to the housing 11, and drives the lock connected to the operating mechanism 16 through the connecting rod 15, so that the action of the lock can be controlled by the handle 14. In one embodiment, the lock is pivotally connected to the contact frame supporting the moving contact 172, and the contact frame is pivotally connected to the housing 11. The operating mechanism 16 also includes a pivotable release member. The release member can, for example, share the same pivot axis with the contact frame. Under normal circumstances, the release member always abuts against the lock, so that the two are locked together to limit the movement of the lock together with the contact frame in the opening direction, thereby ensuring that the moving contact 172 on the contact frame can be stably engaged with the static contact 171 to achieve circuit conduction. When the handle 14 is rotated in the opening direction, the lock and the contact frame are pulled to overcome the pressure of the release member and rotate, thereby driving the moving contact 172 away from the static contact 171 and opening the gate. When the handle 14 is rotated in the closing direction, the lock catch and the contact frame rotate again under the pressure of the tripping member, and drive the moving contact 172 to approach the static contact 171 and close the circuit.

[0036] In addition to being triggered by the handle 14, the operation of the operating mechanism 16 can also be triggered by the tripping mechanism. When a specified current condition (such as a short circuit current or an overload current) occurs, the tripping member will pivot and disengage from the lock under the drive of the tripping mechanism. At this time, the restrictions originally applied to the lock and the contact frame are released, and the circuit breaker 1 is allowed to be opened. Once the specified current condition is eliminated, the driving force applied to the tripping member by the tripping mechanism disappears, and the tripping member will be pressed against the lock again, and the two will be locked again.

[0037] In the illustrated embodiment, the circuit breaker 1 may be provided with two tripping mechanisms, namely a short-circuit tripping mechanism and an overload tripping mechanism.

[0038] The short-circuit tripping mechanism is, for example, an electromagnetic tripping mechanism 19. In one embodiment, the electromagnetic tripping mechanism includes a sleeve fixed in the housing 11, a coil around the outer circumference of the sleeve, a tripping rod movably mounted in the sleeve along the axial direction, an armature sleeved on one end of the tripping rod in the sleeve, and a yoke sleeved on the other end of the tripping rod. The armature forms a driving fit with the tripping rod. A reset spring is abutted between the tripping rod and the armature. One end of the coil is connected to the first terminal 12, and the other end of the coil is connected to the static contact 171.

[0039] The overload tripping mechanism is, for example, a bimetallic strip 18, wherein the bimetallic strip 18 is connected between the moving contact 172 and the second terminal 13. When the current is overloaded, the bimetallic strip 18 is deformed by heat and drives the tripping member to rotate through the transmission member to disconnect from the lock.

[0040] The housing 11 may also be provided with a display window, and the operating mechanism 16 is provided with an indicator that can be switched as the opening and closing states of the circuit breaker 1 change, and the indicator is aligned with the window, thereby informing the operator of the current state of the circuit breaker. In one embodiment, the indicator is movably mounted on the contact support. In another embodiment, the indicator is integrated into the lock.

[0041] In the longitudinal direction Y of the housing 11, and on the other side opposite to the handle 14, an arc extinguishing mechanism 2 is installed, and an electromagnetic tripping mechanism 19 and a contact mechanism 17 are located between the handle 14 and the arc extinguishing mechanism 2. Figure 1 and Figure 2 As shown, the arc extinguishing mechanism 2 is arranged corresponding to the contact mechanism 17, and the extension length of the arc extinguishing mechanism 2 in the transverse direction X of the housing 11 exceeds the movement range of the moving contact 172 in the transverse direction X during opening / closing. In one embodiment, the junction of the moving contact 172 and the static contact 171 is approximately located in the transverse middle of the arc extinguishing mechanism 2.

[0042] Figures 3 to 7 2 shows exemplary details of the arc extinguishing mechanism 2. Figure 6 As shown, the bracket 3 of the arc extinguishing mechanism 2 extends along the transverse direction X of the shell 11, and includes a bottom wall 32 and two side walls 31 located at opposite ends of the bottom wall 32. An accommodating cavity 33 is defined by the bottom wall 32 and the two side walls 31. The bracket 3 has a first end 34 and a second end 35 on opposite sides of its extending direction. An air outlet 321 is formed on the bottom wall 32, and the air outlet 321 is fluidly connected with the outlet 111 of the shell 11. In one embodiment, the air outlet 321 is arranged in two groups, and the two groups are arranged in a direction perpendicular to the XY plane (or the thickness direction of the shell 11), and the multiple air outlets 321 of each group are arranged along the transverse direction X of the shell 11. Further, each air outlet 321 of one group is staggered with each air outlet 321 of another group.

[0043] A plurality of grid plates 4 are arranged in a transverse direction X at intervals in the accommodating cavity 33, and each grid plate 4 extends in a longitudinal direction Y. Baffles 322 may be provided at the first end 34 and the second end 35 of the bracket 3, respectively, to limit the installation area of ​​the grid plate 4 in the accommodating cavity 33. In addition, a plurality of protrusions 323 arranged in a transverse direction X may be formed on the bottom wall 32, and a single grid plate 4 may be positioned by two adjacent protrusions 323. A plurality of grid plates arranged at intervals help to cut the arc generated by the separation of the moving contact and the static contact into a short arc, so that the arc decays at the interval between two adjacent grid plates and is quickly extinguished. The high-temperature gas formed after the arc is extinguished will eventually be discharged through the gas outlet 321 of the bracket 3 and the outlet 111 of the housing 11 (such as Figure 2The specific number of grid plates can be selected as needed. It is understandable that by arranging multiple grid plates in the transverse direction of the housing 11, the number of grid plates can be significantly increased, the heat capacity and arc voltage in the arc extinguishing chamber can be increased, and the breaking capacity of the high voltage DC circuit breaker can be improved.

[0044] like Figure 7 As shown, the grid sheet 4 includes a body 41 and a pair of legs 42 extending from the body 41. The body 41 is disposed in the accommodating cavity 33 of the bracket 3 near the bottom wall 32, and the legs 42 extend from the accommodating cavity 33 in a direction away from the bottom wall 32. A mounting protrusion 45 is formed on the side of the grid sheet 4, and a corresponding mounting opening 311 is formed on the side wall 31 of the bracket 3. The grid sheet 4 is fixed to the bracket 3 by inserting the mounting protrusions 45 into the mounting opening 311 one by one. Each leg 42 may have an extending end 421 extending away from the other leg 42, and the extending end 421 is located above the side wall 31 of the bracket 3.

[0045] An arc-starting groove 44 is formed between the pair of legs 42, and the arc-starting groove 44 extends in the longitudinal direction Y. As shown in the figure, the arc-starting groove 44 can be roughly divided into two sections, wherein the first section 441 is close to the body 41 of the grid 4. In the first section 441, the spacing between the pair of legs 42 is substantially constant. The second section 442 of the arc-starting groove 44 extends from the first section 441 in a direction away from the body 41 and is connected to the first section 441. In the second section 442, the spacing between the pair of legs 42 gradually increases in a direction away from the body 41. This structure of the arc-starting groove, which is larger at the top and smaller at the bottom, helps to guide and cut the arc.

[0046] A first arc guide plate 5 is arranged at the first end 34 of the bracket 3 near the first terminal 12. A portion of the first arc guide plate 5 covers the accommodating cavity 33 at the first end 34, and then extends toward the second end 35 of the bracket 3 near the second terminal 13. In the illustrated embodiment, the extended end of the first arc guide plate 5 can be engaged to the fixing frame of the electromagnetic tripping mechanism 19. The first arc guide plate 5 can be formed with a first groove 51 open to the first end 34 facing away from the bracket 3, and the end surface of the first groove 51 facing the first end 34 of the bracket 3 is engaged with a static contact 171 (or a static contact point). Thereby, the first arc guide plate 5 is connected to the circuit on the static contact side. In this embodiment, the first groove 51 of the first arc guide plate 5 and the surrounding area are also configured as a static contact bracket.

[0047] A second arc guide plate 6 is arranged at the second end 35 of the bracket 3. A portion of the second arc guide plate 6 covers the accommodating cavity 33 at the second end 35 and then extends toward the first end 34 of the bracket 3. The second arc guide plate 6 can form a second groove 61 that is open to the first end 34 of the bracket 3. In the illustrated embodiment, the second groove 61 can be formed by bending the end of the first arc guide plate 6 back toward the second end 35. The second arc guide plate 6 is connected to the overload tripping mechanism through an intermediate connector. Thereby, the second arc guide plate 6 is connected to the circuit from the side of the moving contact. The first groove 51 and the second groove 61 are approximately at the same height in the longitudinal direction Y, and the moving contact 172 performs the tripping and closing movements between the first groove 51 and the second groove 61.

[0048] By forming the first slot and the second slot, the first arc guide plate and the second arc guide plate respectively form loops bent toward each other, and the loop current is used to form magnetic blow within the range of the moving contact and the static contact to prevent the arc from breaking down behind the contacts. Further, the open area 52 of the first slot 51 facing away from the second slot 61 can be larger than the open area 62 of the second slot 61 facing away from the first slot 51, thereby, the first slot 51 is roughly configured as a U-shaped loop, and the second slot 61 is roughly configured as an unsealed O-shaped loop.

[0049] from Figures 1 to 3 It can be seen that the first groove 51 of the first arc guide plate 5 is closer to the transverse middle of the bracket 3 than the second groove 61 of the second arc guide plate 6. Thus, the moving contact 172 basically completes the opening with the static contact 171 in the middle area of ​​the bracket 3, which helps the arc generated by the opening to be evenly struck on both sides of the arc extinguishing mechanism.

[0050] A first magnetizing member or permanent magnet 8 may be provided in the first slot 51, and a second magnetizing member or permanent magnet 9 may be provided in the second slot 61. The magnetizing member or permanent magnet may further increase the magnetization effect, thereby improving the magnetic blowing force of the circuit breaker on the arc under low current.

[0051] A gas-generating sheet 7 may also be provided on the side of the bracket 3 facing the handle 14. The gas-generating sheet 7 is made of a gas-generating material, which generates gas under high temperature environment, can accelerate the flow of the arc, increase the probability of the arc entering the arc extinguishing mechanism, and thus improve the arc extinguishing effect. The gas-generating material is not limited here, for example, it can be at least one of polyamide, polyoxymethylene, and melamine. Two groups of gas-generating sheets 7 can be arranged on opposite sides of the contact mechanism 17 in a direction perpendicular to the XY plane, wherein each group of gas-generating sheets 7 is arranged above a side wall 31 of the bracket 3. Thereby, the contact mechanism 17, especially the area where the moving contact 172 and the static contact 171 are disconnected, is surrounded by the arc extinguishing mechanism 2 (there are a first arc guide plate and a second arc guide plate on opposite sides in the lateral direction, and there are gas-generating sheets on opposite sides in the direction perpendicular to the XY plane), and the arc generated by the disconnection of the moving contact and the static contact is guided to the arc extinguishing grid 4 as much as possible, thereby improving the disconnection speed of the circuit breaker.

[0052] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0053] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by any technician in the field without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. An arc extinguishing mechanism for a circuit breaker, characterized in that: The arc extinguishing mechanism comprises: A bracket (3) extending along a first direction and having a first end (34) and a second end (35) opposite to each other in the first direction, wherein the bracket (3) defines a receiving cavity (33); A plurality of grid sheets (4) are arranged in the accommodation cavity (33) at intervals along the first direction, wherein each grid sheet (4) extends along a second direction that is at an angle to the first direction; A first arc guide plate (5) extending from a first end (34) of the bracket (3) toward a second end (35) of the bracket (3), the first arc guide plate (5) being configured with a first slot (51) open away from the second end (35) of the bracket (3), wherein the first slot (51) is suitable for accessing a circuit from a stationary contact side of the circuit breaker; a second arc guide plate (6) extending from the second end (35) of the bracket (3) toward the first end (34) of the bracket (3), the second arc guide plate (6) being configured with a second slot (61) open away from the first end (34) of the bracket (3), wherein the second slot (61) is suitable for accessing a circuit from the moving contact side of the circuit breaker; An accommodation space is defined between the first slot (51) and the second slot (61) to allow the moving contact (172) of the circuit breaker to move therebetween to open or close the circuit.

2. The arc extinguishing mechanism according to claim 1, characterized in that: The arc extinguishing mechanism also includes a first magnetizing member or a permanent magnet (8) disposed in the first slot (51).

3. The arc extinguishing mechanism according to claim 1, characterized in that: The arc extinguishing mechanism further comprises a second magnetizing member or a permanent magnet (9) disposed in the second slot (61).

4. The arc extinguishing mechanism according to any one of claims 1 to 3, characterized in that: An open area of ​​the first groove (51) facing away from the second groove (61) is larger than an open area of ​​the second groove (61) facing away from the first groove (51).

5. The arc extinguishing mechanism according to any one of claims 1 to 3, characterized in that: Compared to the second groove (61), the first groove (51) is closer to the middle portion of the bracket (3) between the first end (34) and the second end (35).

6. The arc extinguishing mechanism according to any one of claims 1 to 3, characterized in that: The side surface of the first groove (51) facing the second groove (61) has a fixed contact engagement area.

7. The arc extinguishing mechanism according to any one of claims 1 to 3, characterized in that: The plurality of grid sheets (4) include a plurality of first grid sheets and a plurality of second grid sheets, wherein the first grid sheets and the second grid sheets have different lengths in the second direction, and the plurality of first grid sheets (4) and the plurality of second grid sheets (4) are alternately arranged along the first direction.

8. The arc extinguishing mechanism according to any one of claims 1 to 3, characterized in that: The grid plate (4) comprises: Ontology(41); A pair of legs (42) extend from the main body (41) along the second direction, an arc-striking groove (44) is formed between the pair of legs (42), and the arc-striking groove (44) includes a first section (441) close to the main body (41) and a second section (442) away from the main body (41), wherein in the first section (441), the spacing between the pair of legs (42) is constant, and in the second section (442), the spacing between the pair of legs (42) increases gradually along the direction away from the main body (41).

9. A circuit breaker, characterized in that: include: The housing (11) has a transverse direction (X) and a longitudinal direction (Y); a handle (14) pivotably mounted to the housing (11); A contact mechanism (17), comprising a stationary contact (171) and a movable moving contact (172); An operating mechanism (16) comprising a tripping member and a lock connected to the handle (14), wherein the tripping member can be locked with the lock to keep the moving contact (172) in a state of engagement with the stationary contact (171), and the tripping member can be unlocked from the lock to allow the moving contact (172) to be separated from the stationary contact (171); A gate opening mechanism, installed on the housing (11) and capable of driving the release member to unlock the lock; The arc extinguishing mechanism (2) is the arc extinguishing mechanism according to any one of claims 1 to 8, wherein the arc extinguishing mechanism (2) and the handle (14) are arranged on opposite sides of the housing (11) along the longitudinal direction (Y), the static contact (171) is engaged with the side of the first groove (51) of the first arc guide plate (5) facing the second groove (61) of the second arc guide plate (6), and the multiple grid plates (4) are arranged at intervals along the transverse direction (X) of the housing (11), and each grid plate (4) extends along the longitudinal direction (Y) of the housing.

10. The circuit breaker according to claim 9, characterized in that The trip mechanism comprises a bimetallic strip (18) connected to the moving contact (172), wherein the bimetallic strip (18) can deform in response to a preset condition to drive the tripping member to unlock the lock, wherein the second groove (61) of the second arc guide plate (6) is engaged with the bimetallic strip (18).

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