Cover assembly and circuit breaker

Abstract

This utility model belongs to the field of low-voltage electrical appliance technology and discloses a cover assembly and a circuit breaker. The cover assembly provided by this utility model includes an upper cover and a middle cover. The upper cover has a first exhaust hole on its side wall. The middle cover includes a cover body and multiple guide plates. The cover body is located at the upper end of the bottom assembly and cooperates with the bottom assembly to form an arc-extinguishing installation chamber. Multiple arc-extinguishing chambers are arranged within the arc-extinguishing installation chamber along the front-to-back direction. Multiple guide plates are all arranged within the cover body and correspond one-to-one with the multiple arc-extinguishing chambers. Each arc-extinguishing chamber has a reflector plate. The multiple guide plates and multiple reflectors cooperate one-to-one to form air-guiding cavities, which are connected to the corresponding arc-extinguishing chambers. From left to right, each guide plate is inclined downwards, and the top wall of each air-guiding cavity has an air-guiding groove communicating with the first exhaust hole. This cover assembly and circuit breaker ensure arc extinguishing effect, reduce the risk of arc-extinguishing chamber ablation and contact meltdown, and ensure the service life and reliability of the circuit breaker.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical technology, and in particular to a cover assembly and a circuit breaker. Background Technology

[0002] In power systems, circuit breakers are key devices for ensuring the safe operation of circuits, and their core function is to reliably interrupt fault currents. When the circuit breaker contacts break, the instantaneous electric arc releases high temperatures, causing the gas inside the circuit breaker to expand rapidly. The expanding gas carries the electric arc into the arc-extinguishing chamber, where the arc is quickly extinguished through physical processes such as air blowing and cooling. Subsequently, the gas must be discharged through the exhaust vents on the outer casing to restore internal pressure balance.

[0003] Currently, most circuit breakers use a single exhaust structure on the bottom base. While this design meets basic exhaust requirements, it suffers from problems such as a single gas exhaust path and limited efficiency. Although some improved circuit breakers have added exhaust channels to the top cover assembly, in practical applications, the top exhaust channel is prone to gas obstruction and excessive back pressure due to unreasonable structural design. Poor exhaust not only reduces the cooling efficiency of the arc-extinguishing chamber but also allows residual high-temperature gas to continuously act on critical components such as the contacts, significantly increasing the risk of arc-extinguishing chamber ablation and contact meltdown, thus affecting the service life and reliability of the circuit breaker. Utility Model Content

[0004] The purpose of this utility model is to provide a cover assembly and a circuit breaker that ensures arc extinguishing effect, reduces the risk of arc extinguishing chamber ablation and contact meltdown, and ensures the service life and reliability of the circuit breaker.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A cover assembly, disposed on the bottom assembly and cooperating with the bottom assembly to form a circuit breaker, the cover assembly comprising;

[0007] The top cover has a first vent hole on its side wall;

[0008] The middle cover includes a cover body and multiple guide plates. The cover body is disposed at the upper end of the bottom component and cooperates with the bottom component to form an arc-extinguishing installation chamber. Along the front-back direction, multiple arc-extinguishing chambers are disposed in the arc-extinguishing installation chamber. Multiple guide plates are disposed in the cover body and correspond one-to-one with multiple arc-extinguishing chambers. Each arc-extinguishing chamber has a reflector plate. Multiple guide plates and multiple reflector plates cooperate one-to-one to form an air-guiding chamber. Multiple air-guiding chambers are connected to the corresponding arc-extinguishing chambers.

[0009] In this configuration, from left to right, each of the guide plates is inclined downwards, and the top wall of each of the air guide chambers is provided with an air guide groove that communicates with the first exhaust hole.

[0010] As a further technical solution, the lower end face of the guide plate is configured as an arc-shaped guide surface.

[0011] As a further technical solution, the upper cover is configured as an open shell, the open end of the upper cover is connected to the cover body, and a plurality of first exhaust holes are provided on the side wall of the upper cover, and the plurality of first exhaust holes are provided in a one-to-one correspondence with the plurality of air guide grooves.

[0012] As a further technical solution, the air guiding surface of each of the air guiding grooves is inclined upward and to the left.

[0013] As a further technical solution, the upper end of each of the air guide grooves is smoothly transitioned to the outer side of the top wall of the cover body, and / or the lower end of each of the air guide grooves is smoothly transitioned to the inner side of the top wall of the cover body.

[0014] As a further technical solution, the cover body is provided with a first connecting rib and a second connecting rib corresponding to the plurality of arc-extinguishing chambers respectively. The first connecting rib and the second connecting rib are arranged at intervals relative to each other on the cover body and cooperate to form an insertion space for the corresponding reflector to be inserted. The lower ends of each first connecting rib and the second connecting rib are higher than the flow-guiding connection end of the corresponding flow guide plate.

[0015] As a further technical solution, the cover body is also provided with rear guide plates corresponding to the multiple arc-extinguishing chambers one by one. Each rear guide plate is located on the side of the corresponding arc-extinguishing chamber away from the reflector plate and extends in the direction away from the upper cover. The middle part of the lower end face of each rear guide plate is recessed in the direction close to the upper cover to form an exhaust section.

[0016] As a further technical solution, a protective plate is also provided inside the cover body. The protective plate is correspondingly arranged with the armature inside the circuit breaker and is located between the armature and the corresponding arc-extinguishing chamber. The protective plate extends away from the upper cover.

[0017] As a further technical solution, the front and / or rear sidewalls of the top cover are each provided with a second vent hole that communicates with the cover body.

[0018] The circuit breaker includes a bottom assembly and the cover assembly. The bottom assembly includes a base housing and a plurality of arc-blocking plates. The plurality of arc-blocking plates are disposed in the base housing in a one-to-one correspondence with a plurality of arc-extinguishing chambers, and each of the arc-blocking plates is disposed opposite to a corresponding guide plate in the cover assembly.

[0019] A third vent hole is provided on the front and / or rear sidewalls of the base housing.

[0020] As a further technical solution, a plurality of static wiring structures are provided inside the base housing in correspondence with the plurality of arc-extinguishing chambers. A plurality of clearance and flow guiding surfaces are provided on the inner side of the bottom wall of the base housing. Each clearance and flow guiding surface is arranged opposite to the groove on the corresponding static wiring structure, and each clearance and flow guiding surface is inclined downward from left to right.

[0021] As a further technical solution, the width of the avoidance guide surface is smaller than the width of the corresponding trough body along the front-back direction.

[0022] As a further technical solution, the base shell is also provided with a plurality of limiting plug-in plates, each of the limiting plug-in plates is provided on the right side of the arc extinguishing chamber, and each of the reflectors is provided with a limiting rib at the right end, and each limiting plug-in plate is provided with a limiting slot that engages with the corresponding limiting rib.

[0023] Beneficial effects:

[0024] On the one hand, the cover assembly provided by this utility model has a guide plate and a corresponding arc-extinguishing chamber arranged opposite each other inside the middle cover, and the guide plate and the corresponding reflector plate cooperate to form a gas guiding cavity communicating with the corresponding arc-extinguishing chamber; at the same time, the top wall of each gas guiding cavity is provided with a gas guiding groove, and the upper cover connected to the top of the middle cover is provided with a first exhaust hole. Taking one of the guide plates and the corresponding arc-extinguishing chamber as an example, since the guide plate is inclined downward from left to right, after the gas guiding cavity formed by the guide plate and the reflector plate cooperates, the cross-sectional area of ​​the gas guiding cavity gradually decreases from left to right. In this way, a pressure difference is generated between the left side of the gas guiding cavity and the arc-extinguishing chamber. When gas and arc are generated during the operation of the circuit breaker, the gas and arc are transferred to the gas guiding cavity more quickly under the action of the pressure difference, and then discharged from the circuit breaker through the gas guiding groove and the first exhaust hole. In this way, on the one hand, timely gas discharge reduces the pressure in the arc-extinguishing chamber, preventing the arc-extinguishing efficiency from being affected by high-pressure gas in the arc-extinguishing chamber; on the other hand, timely discharge of the electric arc reduces the impact of the high temperature of the electric arc on components such as the arc-extinguishing chamber and the contact blade, reducing the risk of arc-extinguishing chamber ablation and contact blade melting, and ensuring the service life and reliability of the circuit breaker.

[0025] Secondly, by setting a third vent on the base housing, the gas in the lower part of the circuit breaker can be discharged outside the circuit breaker through the third vent, thereby further improving the discharge efficiency and effect of gas and arc in the circuit breaker. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the cover assembly provided in this embodiment of the utility model;

[0027] Figure 2 yes Figure 1 A magnified view of a section at point A in the middle;

[0028] Figure 3 yes Figure 1 A magnified view of a section at point B in the middle;

[0029] Figure 4 This is a schematic diagram of the structure of the middle cover in the cover assembly provided in this utility model embodiment;

[0030] Figure 5 This is a schematic diagram of the structure of the upper cover in the cover assembly provided in this utility model embodiment;

[0031] Figure 6 This is a schematic diagram of the circuit breaker provided in this embodiment of the utility model;

[0032] Figure 7 This is a cross-sectional view of the circuit breaker provided in this embodiment of the utility model;

[0033] Figure 8 yes Figure 7 A magnified view of a section at point C;

[0034] Figure 9 This is a cross-sectional view of the bottom component of the circuit breaker provided in this embodiment of the utility model;

[0035] Figure 10 This is a partial structural schematic diagram of the bottom component in the circuit breaker provided in this embodiment of the utility model;

[0036] Figure 11 yes Figure 8 A magnified view of a section at point D;

[0037] Figure 12 This is a schematic diagram of the structure of the base housing in the circuit breaker provided in this embodiment of the utility model;

[0038] Figure 13 This is a schematic diagram of the structure of the reflector in the circuit breaker provided in this utility model embodiment;

[0039] Figure 14 This is a schematic diagram of the static wiring structure in the circuit breaker provided in this utility model embodiment;

[0040] Figure 15 This is a schematic diagram of the circuit breaker provided in this utility model embodiment, showing how the middle cover and the bottom component cooperate to form an arc-extinguishing installation chamber.

[0041] In the picture:

[0042] 10. Arc extinguishing installation chamber;

[0043] 20. Reflector; 21. Limiting rib; 22. Partition plate;

[0044] 100. Top cover; 110. First vent; 120. Second vent;

[0045] 200. Middle cover; 201. Air guide cavity; 210. Cover body; 211. First connecting rib; 212. Second connecting rib; 220. Guide plate; 221. Arc-shaped guide surface; 222. Guide connection end; 230. Air guide groove; 231. Air guide surface; 240. Rear guide plate; 250. Protective plate; 260. Guide connection plate;

[0046] 400, Base housing; 410, Third exhaust port; 420, Clearance guide surface; 430, Moving contact; 440, Stationary contact; 450, Fastener; 402, Limiting plug plate; 4021, Limiting slot;

[0047] 500. Arc baffle;

[0048] 600. Static connection structure; 601. Tank body. Detailed Implementation

[0049] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0050] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0051] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0052] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0053] This embodiment provides a cover assembly and a circuit breaker. The cover assembly is disposed on the bottom assembly and cooperates with the bottom assembly to form a circuit breaker. This cover assembly and circuit breaker ensure arc extinguishing effect, reduce the risk of arc extinguishing chamber ablation and contact meltdown, and ensure the service life and reliability of the circuit breaker. Specifically, in conjunction with... Figures 1 to 14 As shown, the cover assembly includes an upper cover 100 and a middle cover 200; the upper cover 100 has a first exhaust hole 110 on its side wall; the middle cover 200 includes a cover body 210 and multiple guide plates 220. The cover body 210 is located at the upper end of the bottom assembly and cooperates with the bottom assembly to form an arc-extinguishing installation chamber 10. Along the front-back direction, multiple arc-extinguishing chambers are provided in the arc-extinguishing installation chamber 10. Multiple guide plates 220 are correspondingly arranged in the cover body 210, and each arc-extinguishing chamber has a reflector plate 20. Multiple guide plates 220 and multiple reflector plates 20 cooperate to form an air guide cavity 201, and the multiple air guide cavities 201 are connected to the corresponding arc-extinguishing chambers. From left to right, each guide plate 220 is inclined downwards, and the top wall of each air guide cavity 201 is provided with an air guide groove 230 that communicates with the first exhaust hole 110.

[0054] Since the guide plate 220 is disposed opposite to the corresponding arc-extinguishing chamber in the middle cover 200, and the guide plate 220 and the corresponding reflector 20 cooperate to form an air guide cavity 201 that communicates with the corresponding arc-extinguishing chamber; at the same time, the top wall of each air guide cavity 201 is provided with an air guide groove 230, and the upper cover 100 connected to the top of the middle cover 200 is provided with a first exhaust hole 110. Taking one of the guide plates 220 and its corresponding arc-extinguishing chamber as an example, since the guide plates 220 are inclined downwards from left to right, the cross-sectional area of ​​the air-guiding cavity 201 formed by the guide plates 220 and the reflector plate 20 gradually decreases from left to right. This creates a pressure difference between the left side of the air-guiding cavity 201 and the arc-extinguishing chamber. When gas and arc are generated during circuit breaker operation, they are more quickly transferred into the air-guiding cavity 201 under the action of the pressure difference, and then discharged from the circuit breaker through the air-guiding groove 230 and the first exhaust port 110. Thus, on the one hand, timely gas discharge reduces the pressure in the arc-extinguishing chamber, preventing the arc-extinguishing efficiency from being affected by high-pressure gas in the arc-extinguishing chamber; on the other hand, timely discharge of the arc reduces the impact of the high temperature of the arc on components such as the arc-extinguishing chamber and the contact blades, reducing the risk of arc-extinguishing chamber ablation and contact blade melting, ensuring the service life and reliability of the circuit breaker.

[0055] Other structural details and working principles of the arc-extinguishing chamber are not the focus of this solution. For details, please refer to existing technologies, and will not be elaborated here.

[0056] In this embodiment, the size and tilt angle of the guide plate 220 are not specifically limited. The size and tilt angle of the guide plate 220 can be adjusted according to the actual space inside the circuit breaker to ensure that the cross-sectional area of ​​the air guide cavity 201 gradually decreases from left to right.

[0057] When the gas is guided through the gas guide cavity 201 and discharged through the gas guide groove 230, in order to further reduce the disruption of the original laminar flow state of the gas by the lower end of the guide plate 220 and reduce the occurrence of turbulence at the lower end of the guide plate, in this embodiment, the end face of the lower end of the guide plate is set as an arc-shaped guide surface 221.

[0058] Preferably, the upper cover 100 is configured as an open shell, the open end of the upper cover 100 is connected to the cover body 210, and a plurality of first exhaust holes 110 are provided on the side wall of the upper cover 100, and the plurality of first exhaust holes 110 are provided in a one-to-one correspondence with a plurality of air guide grooves 230.

[0059] Combination Figure 2As shown, with this configuration, when the gas in the arc-extinguishing chamber is guided by the corresponding gas guide cavity 201 and discharged through the gas guide groove 230, it is directly discharged into the first exhaust hole 110 opposite to the gas guide groove 230, thereby shortening the path of the gas from the middle cover 200 and the upper cover 100 to the outside of the cover assembly, thus further improving the exhaust effect. In order to further shorten the path of the gas from the middle cover 200 and the upper cover 100 to the outside of the cover assembly, in this embodiment, multiple first exhaust holes 110 are all provided at the open end of the upper cover 100.

[0060] Preferably, the air guiding surface 231 of each air guiding groove 230 is inclined upward and to the left.

[0061] Combination Figure 2 As shown, with this configuration, when the gas in the air guide cavity 201 is discharged outside the cover assembly through the air guide groove 230, the inclined air guide surface 231 guides the gas in the corresponding air guide cavity 201 to quickly discharge the gas out of the area. In some other embodiments, other sidewalls of the air guide groove 230 can also be configured as air guide surfaces 231.

[0062] When the gas is guided through the gas guide cavity 201 and discharged through the gas guide groove 230, in order to avoid turbulence at the upper and lower ends of the gas guide groove 230, in this embodiment, the upper end of each gas guide groove 230 is smoothly transitioned to the outer side of the top wall of the cover body 210, and the lower end of each gas guide groove 230 is smoothly transitioned to the inner side of the top wall of the cover body 210.

[0063] Preferably, the cover body 210 is provided with a first connecting rib 211 and a second connecting rib 212 corresponding to the multiple arc-extinguishing chambers. The first connecting rib 211 and the second connecting rib 212 are arranged at intervals relative to each other in the cover body 210 and cooperate to form an insertion space for the corresponding reflector 20 to be inserted. The lower ends of the first connecting rib 211 and the second connecting rib 212 are both higher than the flow-guiding connection end 222 of the corresponding flow guide plate 220.

[0064] Combination Figure 2 and Figure 8As shown, each guide plate 220 is connected to the top wall of the middle cover 200 through a corresponding guide plate 260. The guide plate 220 and the corresponding guide plate 260 form an angle. For ease of explanation, the upper end of the guide plate 220, that is, the connection end between the guide plate 220 and the corresponding guide plate 260, is referred to as the guide connection end 222. Since the lower ends of the first connecting rib 211 and the second connecting rib 212 are both higher than the guide connection end 222 of the corresponding guide plate 220, when the gas in each arc-extinguishing chamber is guided by the gas guide cavity 201 and discharged from the circuit breaker through the gas guide groove 230, the gas can be prevented from being blocked by the first connecting rib 211 and the second connecting rib 212 and flowing back in the corresponding gas guide cavity 201, so as to further ensure the smoothness and effect of exhaust. The reflector 20 is inserted into the cover body 210 through the corresponding insertion space. The insertion space limits the reflector 20, improving the convenience of connection between the reflector 20 and the cover body 210 while ensuring the connection strength and stability of the reflector 20.

[0065] Preferably, the cover body 210 is further provided with rear guide plates 240 corresponding to a plurality of arc-extinguishing chambers. Each rear guide plate 240 is located on the side of the corresponding arc-extinguishing chamber away from the reflector plate 20 and extends in the direction away from the upper cover 100. The middle part of the lower end face of each rear guide plate 240 is recessed in the direction close to the upper cover 100 to form an exhaust section.

[0066] Some of the gas generated during the operation of the circuit breaker will be ejected later, combined with Figure 1 As shown, by setting a rear guide plate 240 and forming an exhaust section at the lower end of the rear guide plate 240, it is ensured that the gas injected afterward in each arc-extinguishing chamber can be discharged outside the circuit breaker through the corresponding exhaust section, so as to avoid the situation where the injected gas impacts other components inside the circuit breaker.

[0067] In a circuit breaker, an armature is located on the right side of one of the arc-extinguishing chambers. During operation, the gas injected after the circuit breaker may impact the armature. When the armature is impacted by the gas, it may deflect, causing the circuit breaker to trip erroneously under normal current. Furthermore, when the direction of the gas injected after the circuit breaker is opposite to the direction of the armature's movement, it may cancel out part of the electromagnetic attraction, resulting in a delay in tripping and missing the optimal arc-extinguishing opportunity, thus increasing the risk of contact erosion. To reduce the probability of these problems, in this embodiment, a protective plate 250 is also provided inside the cover body 210. The protective plate 250 is correspondingly positioned inside the circuit breaker's armature and is located between the armature and the corresponding arc-extinguishing chamber. The protective plate 250 extends away from the upper cover 100. The protective plate 250 can deflect the flow direction of the gas injected after the circuit breaker, reducing the direct impact force on the armature.

[0068] Preferably, the front and / or rear side walls of the cover 100 are provided with a second vent 120 that communicates with the cover body 210.

[0069] Combination Figure 5 As shown, during the operation of the circuit breaker, some of the gas injected afterward will impact the space between the middle cover 200 and the upper cover 100 through the gap in the middle cover 200. By providing multiple second exhaust holes 120, the gas can be discharged outside the cover assembly through these holes, thereby further improving the exhaust efficiency and effect of the cover assembly and reducing the risk of gas clogging inside the circuit breaker and impacting other components. The specific number, location, and size of the second exhaust holes 120 can be adaptively adjusted according to actual needs, and are not specifically limited in this embodiment.

[0070] In this embodiment, both the first exhaust hole 110 and the second exhaust hole 120 are rectangular holes. In other embodiments, the first exhaust hole 110 and the second exhaust hole 120 can be adapted to be circular holes, elliptical holes, rounded rectangular holes, trapezoidal holes, etc., according to actual needs, and are not limited to the rectangular holes in this embodiment.

[0071] Combination Figures 6 to 14 As shown, the circuit breaker includes a bottom assembly and the aforementioned cover assembly. The bottom assembly includes a base housing 400 and multiple arc-isolating plates 500. The multiple arc-isolating plates 500 are disposed within the base housing 400 in a one-to-one correspondence with multiple arc-extinguishing chambers, and each arc-isolating plate 500 is disposed opposite to a corresponding guide plate 220 in the cover assembly. When an electric arc is generated inside the circuit breaker, the arc-isolating plates 500 can isolate the arc, prevent the arc from spreading to other components, avoid causing faults such as short circuits, and ensure a relatively independent operating environment for each component inside the circuit breaker. At the same time, through the opposite arrangement of the arc-isolating plates 500 and the corresponding guide plates 220, the arc-isolating plates 500 can guide the expanding gas generated during the arc extinguishing process to flow in a predetermined direction, so that the gas passes more smoothly through the arc-extinguishing chamber and is discharged from the housing after being guided by the corresponding guide plates 220, reducing turbulence caused by gas disturbance, further improving arc extinguishing efficiency and exhaust effect, and reducing the risk of arc-extinguishing chambers, contact blades and other components being burned by high-temperature gas.

[0072] Combination Figure 6 and Figure 9 As shown, a third vent hole 410 is provided on the front and / or rear sidewalls of the base housing 400. By providing multiple third vent holes 410, gas in the lower part of the circuit breaker can be discharged outside the circuit breaker through multiple third vent holes 410, thereby further improving the venting efficiency and venting effect of the circuit breaker. The specific number, location, and size of the third vent holes 410 can be adaptively adjusted according to actual needs, and are not specifically limited in this embodiment. The specific arrangement of the third vent holes 410 is the same as that of the first vent hole 110 and the second vent hole 120, and will not be described again here.

[0073] Preferably, a plurality of static wiring structures 600 are provided inside the base housing 400 corresponding to a plurality of arc-extinguishing chambers. A plurality of clearance guide surfaces 420 are provided on the inner side of the bottom wall of the base housing 400. Each clearance guide surface 420 is arranged opposite to the groove 601 on the corresponding static wiring structure 600, and each clearance guide surface 420 is inclined downward from left to right.

[0074] Combination Figure 7 , Figure 8 as well as Figure 14 Each stationary connection structure 600 has its front end fixed to the base housing 400 via corresponding fasteners 450. In the front-to-back direction, the fasteners 450 are positioned close to the sides of the corresponding stationary connection structure 600, thus ensuring a good connection while minimizing the space occupied by the fasteners 450 within the corresponding arc-extinguishing chamber. By providing clearance guide surfaces 420, the space at the bottom corner of the corresponding arc-extinguishing chamber is reduced, thereby reducing the possibility of gas backflow at the bottom corner and further improving the exhaust effect. Simultaneously, since each clearance guide surface 420 is an inclined surface, interference between the clearance guide surface 420 and the groove 601 on the corresponding stationary connection structure 600 is avoided, preventing air blockage between the clearance guide surface 420 and the corresponding groove 601. This reduces the risk of the arc-extinguishing chamber being exposed to the external environment due to increased gas pressure inside the circuit breaker caused by the inability to expel gas in time, leading to cracks at the connection between the circuit breaker cover body 210 and the base housing 400. In addition, in this embodiment, the risk of air blockage between the guide surface 420 and the corresponding tank 601 is further reduced. The left side of the tank 601 protrudes away from the corresponding arc-extinguishing chamber, thereby increasing the spatial area of ​​the tank 601 and improving the exhaust effect at the tank 601.

[0075] To avoid the flow-avoiding surface 420 getting stuck with the corresponding trough 601, which would affect the exhaust effect at the bottom corner of the arc-extinguishing chamber, in this embodiment, the width of the flow-avoiding surface 420 is smaller than the width of the corresponding trough 601 along the front-to-back direction. In this embodiment, the tilt angle of the flow-avoiding surface 420 is not specifically limited and can be adaptively adjusted according to the actual situation of the circuit breaker.

[0076] Preferably, the base housing 400 is further provided with a plurality of limiting plug-in plates 402, each limiting plug-in plate 402 being located on the right side of the arc-extinguishing chamber, and each reflector 20 having a limiting rib 21 at its right end. Each limiting plug-in plate 402 is provided with a limiting slot 4021 that engages with the corresponding limiting rib 21. The limiting plug-in plates 402 are used to reduce the movement of airflow and particulate matter towards the moving contact 430, thereby increasing dielectric properties.

[0077] When the stationary contact 440 and the moving contact 430 disconnect and generate an electric arc, the internal temperature of the circuit breaker rises sharply, causing the internal gas to expand rapidly. The reflector plate 20 will shrink and deform under the high temperature generated by the electric arc. Figures 9 to 11 As shown, taking one of the reflectors 20 as an example, the limiting rib 21 is engaged with the corresponding limiting slot 4021 so that the reflector 20 is limited to the limiting plug plate 402. In this way, when the reflector 20 is heated and shrinks, the limiting rib 21 and the corresponding limiting slot 4021 cooperate to limit the displacement range of the rear end of the reflector 20, so that the reflector 20 cannot move arbitrarily to a position that may jam the contact knife, ensuring the smooth operation of the contact knife during the opening and closing process and maintaining the normal working state of the circuit breaker. In this embodiment, the number of upper limit ribs 21 set in the limit plug plate 402 and the relative position and distance between each limit rib 21 are not specifically limited. The number of upper limit slots 4021 set in the limit plug plate 402 and the relative position and distance between each limit slot 4021 are set in accordance with the limit plug plate 402. The displacement range of the rear end of the reflector plate 20 can be limited by the cooperation between the limit ribs 21 and the corresponding limit slots 4021, and interference between the limit ribs 21 and other components in the circuit breaker can be avoided.

[0078] In addition, a partition 22 is provided on the left side of the front end of the corresponding reflector 20. By setting the partition 22, the entry of foreign objects such as metal debris into the circuit breaker can be reduced, thereby reducing the risk of phase-to-phase short circuits or grounding faults caused by insulation deterioration; it also reduces the probability of the contact blades being obstructed by foreign objects during opening and closing, ensuring the smooth operation of the contact blades during opening and closing. The material of the partition 22 can be selected according to actual needs, such as epoxy resin or glass fiber reinforced plastic, and is not specifically limited in this embodiment.

[0079] The specific structure and working principle of other components in the circuit breaker, such as contact blades, current transformers, and trip units, as well as the relative positional relationships between these components, are described in reference to existing technologies and will not be repeated in this embodiment.

[0080] This embodiment uses the cover assembly installed in a three-phase four-wire circuit breaker as an example for illustration. Therefore, the circuit breaker in the attached drawings of this embodiment has three arc-extinguishing chambers. In other embodiments, the number of cover assemblies and arc-extinguishing chambers can be set according to actual needs, and is not limited to this embodiment and the attached drawings of the embodiment.

[0081] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A cover assembly, disposed on a bottom assembly and cooperating with the bottom assembly to form a circuit breaker, characterized in that, The cover assembly includes: The upper cover (100) has a first vent (110) on its side wall; The middle cover (200) includes a cover body (210) and multiple guide plates (220). The cover body (210) is disposed at the upper end of the bottom component and cooperates with the bottom component to form an arc-extinguishing installation chamber (10). Along the front-back direction, multiple arc-extinguishing chambers are disposed in the arc-extinguishing installation chamber (10). Multiple guide plates (220) are disposed in the cover body (210) and correspond one-to-one with multiple arc-extinguishing chambers. Each arc-extinguishing chamber has a reflector plate (20). Multiple guide plates (220) and multiple reflector plates (20) cooperate one-to-one to form an air guide chamber (201). The air guide chamber (201) is connected to the corresponding arc-extinguishing chamber. Among them, from left to right, each of the guide plates (220) is inclined downward, and the top wall of each of the air guide chambers (201) is provided with an air guide groove (230) that communicates with the first exhaust hole (110).

2. The cover assembly according to claim 1, characterized in that, The lower end face of the guide plate (220) is set as an arc-shaped guide surface (221).

3. The cover assembly according to claim 1, characterized in that, The upper cover (100) is configured as an open shell, and the open end of the upper cover (100) is connected to the cover body (210). A plurality of first exhaust holes (110) are provided on the side wall of the upper cover (100), and the plurality of first exhaust holes (110) are provided in a one-to-one correspondence with the plurality of air guide grooves (230).

4. The cover assembly according to claim 3, characterized in that, The air guiding surface (231) of each of the air guiding grooves (230) is inclined upward and to the left.

5. The cover assembly according to claim 1, characterized in that, The upper end of each of the air guide grooves (230) is smoothly transitioned to the outer side of the top wall of the cover body (210), and / or the lower end of each of the air guide grooves (230) is smoothly transitioned to the inner side of the top wall of the cover body (210).

6. The cover assembly according to any one of claims 1-5, characterized in that, The cover body (210) is provided with a first connecting rib (211) and a second connecting rib (212) corresponding to the plurality of arc-extinguishing chambers. The first connecting rib (211) and the second connecting rib (212) are arranged at intervals on the cover body (210) and cooperate to form an insertion space for the corresponding reflector (20) to be inserted. The lower ends of each first connecting rib (211) and the second connecting rib (212) are higher than the flow-guiding connection end (222) of the corresponding flow guide plate (220).

7. The cover assembly according to any one of claims 1-5, characterized in that, The cover body (210) is also provided with rear guide plates (240) corresponding to the multiple arc-extinguishing chambers. Each rear guide plate (240) is located on the side of the corresponding arc-extinguishing chamber away from the reflector plate (20) and extends away from the upper cover (100). The middle part of the lower end face of each rear guide plate (240) is recessed towards the upper cover (100) to form an exhaust section.

8. The cover assembly according to any one of claims 1-5, characterized in that, The cover body (210) is also provided with a protective plate (250), which is correspondingly provided with the armature in the circuit breaker and located between the armature and the corresponding arc extinguishing chamber, and the protective plate (250) extends away from the upper cover (100).

9. The cover assembly according to any one of claims 1-5, characterized in that, The front and / or rear side walls of the top cover (100) are each provided with a second vent (120) that communicates with the cover body (210).

10. A circuit breaker, characterized in that, The device includes a bottom assembly and a cover assembly as described in any one of claims 1-9. The bottom assembly includes a base housing (400) and a plurality of arc-damping plates (500). The plurality of arc-damping plates (500) are disposed in the base housing (400) in a one-to-one correspondence with a plurality of arc-extinguishing chambers, and each of the arc-damping plates (500) is disposed opposite to a corresponding guide plate (220) in the cover assembly. The base housing (400) is provided with a third vent hole (410) on the front side wall and / or the rear side wall.

11. The circuit breaker according to claim 10, characterized in that, The base housing (400) is provided with a plurality of static wiring structures (600) corresponding to the plurality of arc-extinguishing chambers. The bottom wall of the base housing (400) is provided with a plurality of clearance guide surfaces (420). Each clearance guide surface (420) is provided opposite to the groove (610) on the corresponding static wiring structure (600), and each clearance guide surface (420) is inclined downward from left to right.

12. The circuit breaker according to claim 11, characterized in that, Along the front-to-back direction, the width of the avoidance guide surface (420) is smaller than the width of the corresponding trough (610).

13. The circuit breaker according to claim 10, characterized in that, The base housing (400) is also provided with a plurality of limiting plug-in plates (402), each of the limiting plug-in plates (402) is provided on the right side of the arc extinguishing chamber, and each of the reflectors (20) is provided with a limiting rib (21) at the right end, and each of the limiting plug-in plates (402) is provided with a limiting slot (4021) that engages with the corresponding limiting rib (21).

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