A switching unit and a switch

Abstract

The application provides a switch unit and a switch, and relates to the technical field of power equipment. The switch unit comprises a shell, an arc extinguishing chamber and a contact assembly installed in the shell. An air inlet is arranged at one end of the arc extinguishing chamber close to the contact assembly, and an air outlet is arranged at one end of the arc extinguishing chamber away from the contact assembly. A gap is formed between the inner wall surface of the shell and the arc extinguishing chamber. Thus, at least part of the electric arc and the hot gas flow generated when the contact assembly is opened first enters the inside of the arc extinguishing chamber from the air inlet, then flows to the gap between the inner wall surface of the shell and the arc extinguishing chamber from the air outlet of the arc extinguishing chamber, and then flows to the air inlet from the gap between the inner wall surface of the shell and the arc extinguishing chamber, thereby realizing air flow circulation. In this process, the flow path of the electric arc and the hot gas flow is lengthened, and the effect of arc cooling and extinguishing can be enhanced. In the process of flowing, the electric arc and the hot gas flow can squeeze and push the relatively cold gas flow out from the side of the arc extinguishing chamber close to the contact assembly, thereby accelerating the cooling process near the contact assembly.

Description

Technical Field

[0001] This application relates to the field of power equipment technology, and more specifically, to a switching unit and a switch. Background Technology

[0002] As the core actuator of a circuit control system, the switch plays a crucial role in power transmission and management. It achieves precise switching between on and off states of a circuit through mechanical linkage or electronic control, and is widely used in power distribution, equipment protection, and energy management, covering multiple fields including civil, industrial, commercial, and public infrastructure. The contact assembly, consisting of a fixed stationary contact and a movable moving contact, is responsible for the physical execution of circuit on / off. When the operating mechanism drives the moving contact, the contact pair closes to form a conductive circuit; when they separate, the current path is cut off. This electromechanical conversion characteristic makes it the core component determining the switch's performance.

[0003] During contact breaking, the high-temperature electric arc generated between the contact surfaces needs to be effectively extinguished by an arc-extinguishing system. Traditional arc-extinguishing devices guide the arc to the arc-extinguishing grid using electromagnetic force, converting a long arc into multiple short arcs connected in series, thereby increasing the arc voltage, suppressing the fault current, and eventually extinguishing the arc. However, due to the limited gas flow path within the arc-extinguishing device, the arc-extinguishing effect is poor, causing the switch to fail to meet the UL98B standard requirement of 240 operations per hour (400-cycle life test). Furthermore, the current switch breaking capacity cannot meet the higher breaking requirements of photovoltaic systems at the DC-PV2 level. Utility Model Content

[0004] The purpose of this application is to provide a switching unit and a switch in order to address the shortcomings of the prior art.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0006] In one aspect of this application, a switching unit is provided, including a housing and an arc-extinguishing chamber and a contact assembly installed in the housing. An air inlet is provided at one end of the arc-extinguishing chamber near the contact assembly, and an air outlet is provided at one end of the arc-extinguishing chamber away from the contact assembly.

[0007] There is a gap between the inner wall of the housing and the arc-extinguishing chamber. When the contact assembly is opened, at least part of the arc generated flows from the outlet through the gap between the inner wall of the housing and the arc-extinguishing chamber to the inlet.

[0008] Optionally, the gap between the inner wall of the shell and the arc-extinguishing chamber, together with the arc-extinguishing chamber, constitutes an airflow circulation channel for at least part of the electric arc. The airflow circulation channel includes a first channel and a second channel connected in sequence. The first channel is the flow channel of the electric arc in the arc-extinguishing chamber, and the second channel is the gap between the inner wall of the shell and the outer wall of the arc-extinguishing chamber. At least part of the electric arc first flows through the first channel to the second channel, and then flows through the second channel to the first channel.

[0009] Optionally, a gas generating element is provided at one end of the arc-extinguishing chamber near the contact assembly. The gas generating element is used to generate gas to drive the electric arc into the interior of the arc-extinguishing chamber. The outer wall surface of the gas generating element along the thickness direction of the shell is flush with the outer wall surface of the arc-extinguishing chamber along the thickness direction of the shell.

[0010] Optionally, the dimension of the gas generating element at the end near the contact assembly along the thickness direction of the housing is larger than the dimension of the gas generating element at the end near the arc extinguishing chamber along the thickness direction of the housing.

[0011] Optionally, at least one first groove is provided on the outer wall surface of the gas generating component on the side opposite to the air inlet along the thickness direction of the housing, and the electric arc flowing to the second channel flows to the first channel through the first groove.

[0012] Optionally, opposing first protrusions are provided on the top wall and / or bottom wall of the housing, and the arc-extinguishing chamber is clamped between the opposing first protrusions, between the first protrusion and the top wall, or between the first protrusion and the bottom wall, so that there is a gap between the arc-extinguishing chamber and the top wall and / or bottom wall of the housing.

[0013] Optionally, the contact assembly includes a stationary contact and a moving contact mounted on the housing. A stationary contact piece and an arc-inducing piece are provided at the end of the stationary contact near the moving contact. The stationary contact piece cooperates with the moving contact to close or open the circuit, and the arc-inducing piece is connected to the arc-extinguishing chamber.

[0014] Optionally, the arc-starting plate includes a connecting part and an arc-starting part connected in sequence. The connecting part is connected to the stationary contact piece, and the arc-starting part is connected to the arc-extinguishing chamber. The end of the connecting part near the arc-extinguishing chamber is recessed into the end of the stationary contact piece near the arc-extinguishing chamber.

[0015] Optionally, at least one heat dissipation groove is provided on the housing.

[0016] Optionally, a first through hole is provided near the air outlet of the housing, and part of the electric arc generated when the contact assembly is opened flows out of the housing through the air inlet, the air outlet and the first through hole in sequence.

[0017] In another aspect of the embodiments of this application, a switch is provided, including a handle, an operating mechanism, and a plurality of switch units as described above, wherein the handle is driven and connected to the plurality of switch units respectively via the operating mechanism.

[0018] The beneficial effects of this application include:

[0019] This application provides a switching unit, including a housing, an arc-extinguishing chamber, and a contact assembly installed within the housing. An air inlet is provided at the end of the arc-extinguishing chamber near the contact assembly, and an air outlet is provided at the end of the arc-extinguishing chamber away from the contact assembly. A gap exists between the inner wall of the housing and the arc-extinguishing chamber. At least a portion of the electric arc generated when the contact assembly is opened flows from the air outlet through the gap between the inner wall of the housing and the arc-extinguishing chamber to the air inlet. By providing a gap between the inner wall of the housing and the arc-extinguishing chamber, at least a portion of the electric arc and hot air generated when the contact assembly is opened first enters the arc-extinguishing chamber from the air inlet, then flows from the air outlet of the arc-extinguishing chamber to the gap between the inner wall of the housing and the arc-extinguishing chamber, and then flows back to the air inlet from the gap between the inner wall of the housing and the arc-extinguishing chamber, thus achieving airflow circulation. During this process, the flow path of the electric arc and hot air in the switching unit is extended, which enhances the cooling and extinguishing effect of the arc. Furthermore, the arc and hot airflow, during their flow, can compress and push the cooler airflow from the side of the arc-extinguishing chamber closest to the contact assembly, thereby accelerating the cooling process near the contact assembly. Airflow circulation not only helps to effectively release arc heat but also accelerates the dispersion and dissipation of the arc, significantly improving the cooling efficiency of the contact assembly. Moreover, the extended arc flow path allows for arc segmentation, increasing the arc voltage, further reducing fault current, and effectively preventing arc retreat. This enables the switching unit to operate stably at frequencies up to 240 cycles / hour, significantly increasing the operating frequency of the switching unit while ensuring a long service life even at high frequencies. In addition, this design can improve the breaking capacity of the switching unit, meeting the high requirements of electrical equipment for the DC-PV2 standard, ensuring the safety and reliability of the equipment. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is one of the structural schematic diagrams of a switching unit provided in an embodiment of this application;

[0022] Figure 2 A flow diagram of an electric arc within an airflow circulation channel is provided as an embodiment of this application;

[0023] Figure 3 This is a second schematic diagram of the structure of a switching unit provided in an embodiment of this application;

[0024] Figure 4This is a schematic diagram of the structure of a gas generating component and an arc-extinguishing chamber combined according to an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the structure of a base for a housing provided in an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of the structure of an end cap of a housing provided in an embodiment of this application;

[0027] Figure 7 This is the third schematic diagram of a switching unit provided in the embodiments of this application;

[0028] Figure 8 This is a schematic diagram of the structure of a stationary contact provided in an embodiment of this application.

[0029] Icons: 1-Shell; 11-First protrusion; 12-Base; 121-Second groove; 13-End cap; 131-Second protrusion; 14-Heat sink; 15-First through hole; 2-Arc extinguishing chamber; 3-Contact assembly; 31-Moving contact; 32-Stationary contact; 321-Stationary contact piece; 322-Arc ignition piece; 3221-Connecting part; 3222-Arc ignition part; 4-Gas generating component; 41-First groove; z-Shell thickness direction. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. It should be noted that, unless otherwise specified, the various features in the embodiments of this application can be combined with each other, and the combined embodiments are still within the protection scope of this application.

[0032] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0033] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "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 when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, 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, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0034] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0035] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] Switches are core components of circuit control systems, responsible for precisely switching the on and off states of circuits, and are widely used in power distribution, equipment protection, and energy management. Their key component is the contact system, consisting of a stationary contact 32 and a moving contact 31. The rotation of the moving contact 31 closes and opens the circuit. During contact breaking, the electric arc must be extinguished by an arc-extinguishing system. Traditional arc-extinguishing devices use electromagnetic force to guide the arc to an arc-extinguishing grid, converting a long arc into a short arc and suppressing fault current. However, the arc-extinguishing effect is limited, causing the switch to fail to meet the higher frequency requirements of the UL98B standard. Furthermore, the switching capacity cannot meet the requirements of the DC-PV2 level of photovoltaic systems.

[0037] To address the aforementioned problems, one aspect of this application provides a switching unit, such as... Figure 1 and Figure 2As shown, the switching unit mainly includes a housing 1, an arc-extinguishing chamber 2, and a contact assembly 3. The arc-extinguishing chamber 2 and the contact assembly 3 are installed inside the housing 1. An air inlet is provided at the end of the arc-extinguishing chamber 2 near the contact assembly 3, and an air outlet is provided at the end of the arc-extinguishing chamber 2 away from the contact assembly 3. A certain gap is maintained between the inner wall of the housing 1 and the arc-extinguishing chamber 2 to guide at least part of the arc generated when the contact assembly 3 is opened to flow from the air outlet through the gap between the inner wall of the housing 1 and the arc-extinguishing chamber 2 to the air inlet, thereby effectively extending the flow path of the arc and the hot air, and thus improving the arc extinguishing effect.

[0038] Specifically, during the opening process of contact assembly 3, the generation of electric arc and hot airflow is unavoidable, and the continuous presence of electric arc and hot airflow has a significant impact on the performance of the switching unit. By setting a gap between the inner wall of housing 1 and arc-extinguishing chamber 2, at least part of the electric arc and hot airflow generated when contact assembly 3 opens first enters the interior of arc-extinguishing chamber 2 from the air inlet, then flows from the air outlet of arc-extinguishing chamber 2 to the gap between the inner wall of housing 1 and arc-extinguishing chamber 2, and then flows from the gap between the inner wall of housing 1 and arc-extinguishing chamber 2 back to the air inlet, thus achieving airflow circulation. In this process, the flow path of electric arc and hot airflow in the switching unit is extended, which can enhance the cooling and extinguishing effect of electric arc. Moreover, during the flow process, electric arc and hot airflow can compress and push the cooler airflow from the side of arc-extinguishing chamber 2 closer to contact assembly 3, thereby accelerating the cooling process near contact assembly 3. Airflow circulation not only helps to effectively release the heat of electric arc, but also accelerates the dispersion and disappearance of electric arc, thereby significantly improving the cooling efficiency of contact assembly 3. Furthermore, extending the arc's flow path allows for arc segmentation, increases arc voltage, further reduces fault current, and effectively prevents arc retreat.

[0039] It should be noted that the arc extinguishing effect can be further improved by optimizing the airflow path design, adding airflow guides, and adopting forced airflow circulation. For example, a multi-channel design allows the arc and hot airflow to be distributed more evenly to all areas of the arc extinguishing chamber 2, enhancing cooling efficiency; a forced airflow system can accelerate airflow circulation, ensuring good arc control, especially during high-frequency operation. Secondly, the material selection for the arc extinguishing chamber 2 is also crucial; using materials with high temperature resistance and high thermal conductivity can effectively improve the heat dissipation rate and reduce the impact of the arc on the switching unit. To further optimize the arc extinguishing effect, an adjustable gap structure can be designed, allowing for flexible adjustment of the airflow size according to different operating conditions, thereby achieving more precise arc cooling and extinction. In addition, by integrating an arc monitoring and feedback system, the arc status can be monitored in real time, and the airflow intensity and direction can be adjusted, further improving the stability and safety of the switching unit.

[0040] Overall, the design of this application enables the switching unit to operate stably at frequencies up to 240 cycles per hour, significantly improving the operating frequency of the switching unit while ensuring a long service life even at high frequencies. Furthermore, this switching unit design enhances its breaking capacity, meeting the high requirements of electrical equipment for the DC-PV2 standard and ensuring the safety and reliability of the equipment.

[0041] Optionally, such as Figure 3 As shown, the arc-extinguishing chamber 2 has an arc-extinguishing cavity inside, with an air inlet and an air outlet connected to the arc-extinguishing cavity, thus forming an inlet and outlet channel for the electric arc and hot airflow. A first through hole 15 is provided near the air outlet on the housing 1. When the contact assembly 3 is tripped, part of the electric arc and hot airflow generated flows out of the housing 1 through the air inlet, the arc-extinguishing cavity, the air outlet, and the first through hole 15.

[0042] Specifically, when the contact assembly 3 is tripped, a portion of the arc and hot airflow first enters the arc-extinguishing chamber through the air inlet, then flows through the airflow path inside the arc-extinguishing chamber to the air outlet, and then flows from the air outlet to the gap between the inner wall of the housing 1 and the arc-extinguishing chamber 2, and then from the gap between the inner wall of the housing 1 and the arc-extinguishing chamber 2 back to the air inlet, entering the arc-extinguishing chamber through the air inlet. This extended flow path of the arc in this area, along with the compression and pushing of the arc and hot airflow during flow, allows the cooler airflow to be discharged from the side of the arc-extinguishing chamber 2 near the contact assembly 3, accelerating the cooling process inside the switching unit (especially near the contact assembly 3), and promoting the decomposition and extinguishing of the arc through continuous circulation. Another portion of the arc and hot airflow enters the arc-extinguishing chamber through the air inlet, flows out through the air outlet to the edge of the housing 1, and then flows out through the first through-hole 15 on the side wall of the housing 1 to the outside of the housing 1. This structural design not only allows the arc to undergo multiple arc-extinguishing stages within the arc-extinguishing chamber, but also effectively accelerates the arc extinguishing speed through two independent paths.

[0043] In summary, this dual-path arc extinguishing design allows the arc and hot airflow to be cooled and gradually extinguished through the arc extinguishing chamber 2 and the gap between the inner wall of the housing 1 and the arc extinguishing chamber 2. The second path, through the arc extinguishing chamber 2 and the first through-hole 15, directly guides the arc and hot airflow to the outside of the housing 1, thereby accelerating the arc extinguishing speed and reducing the long-term impact of the arc on the switching unit. This design significantly improves the stability and reliability of the switching unit under high-frequency operation and enhances its resistance to arc impacts, especially under high load and complex current conditions, ensuring the high efficiency of the switching unit in multiple operations.

[0044] Optionally, the gap between the inner wall of the housing 1 and the arc-extinguishing chamber 2, together with the arc-extinguishing chamber 2, constitutes at least part of the airflow circulation channel for the electric arc and the hot airflow. In the arc-extinguishing chamber, multiple arc-extinguishing grids are spaced apart, and the gap between the arc-extinguishing grids constitutes the first channel for the electric arc and the hot airflow to circulate in the airflow circulation channel. The gap between the inner wall of the housing 1 and the outer wall of the arc-extinguishing chamber 2 constitutes the second channel. The first channel and the second channel are connected through the air inlet and the air outlet to form a complete airflow circulation channel.

[0045] Specifically, when the contact assembly 3 is opened, the electric arc and hot airflow first enter the arc-extinguishing chamber through the air inlet, flow along the first channel (i.e., the gap between the arc-extinguishing grid plates), and are gradually cooled. Subsequently, the electric arc and hot airflow flow out through the first channel and enter the second channel, i.e., the gap between the inner wall of the housing 1 and the outer wall of the arc-extinguishing chamber 2. In this channel, the exchange of hot and cold airflow continues to remove heat from the electric arc, helping to further extinguish it. The electric arc and hot airflow also compress and push the cooler airflow out from the side of the arc-extinguishing chamber 2 closest to the contact assembly 3. Then, the electric arc and hot airflow flow back to the first channel, forming a closed circular circulation path, repeating continuously until the electric arc is completely extinguished.

[0046] In summary, the two-stage airflow circulation path design effectively extends the arc extinction time and improves cooling efficiency. The circulation of the arc and hot airflow between the first and second channels not only increases the arc's cooling opportunities but also effectively segments the arc, reducing damage to the equipment. Furthermore, this design allows for rapid heat dissipation from the arc and hot airflow within the arc-extinguishing chamber 2, avoiding the risk of equipment failure due to localized overheating. Through the synergistic effect of the dual channels, the arc cooling and extinction speed can be significantly improved, thereby ensuring the high-frequency operation capability and long lifespan of the switching unit.

[0047] Optionally, such as Figures 2 to 4 As shown, a gas generating element 4 is provided at one end of the arc-extinguishing chamber 2 near the contact assembly 3. The gas generating element 4 generates gas through chemical or physical means. This gas can effectively drive the electric arc and hot air flow into the interior of the arc-extinguishing chamber 2 and quickly remove the heat of the electric arc and hot air flow, thereby accelerating the arc extinguishing and cooling speed.

[0048] Specifically, when the contact assembly 3 trips and generates an electric arc and hot airflow, the gas generating component 4 immediately activates, producing a certain amount of gas. This gas is guided into the arc-extinguishing chamber 2 through a precisely controlled path, thereby accelerating the flow of the electric arc and hot airflow and guiding it to the appropriate position within the arc-extinguishing chamber 2. Through the action of the gas, the gas generating component 4 can rapidly propel the electric arc and hot airflow into the arc-extinguishing chamber, creating an effective cooling and arc-extinguishing effect. The addition of this gas not only accelerates the movement speed of the electric arc and hot airflow but also, through effective airflow exchange, allows the electric arc to decompose and extinguish more rapidly within the arc-extinguishing chamber 2. The outer wall surface of the gas generating component 4 along the thickness z direction of the housing is flush with the outer wall surface of the arc-extinguishing chamber 2 along the thickness z direction of the housing. This design simplifies the assembly of the gas generating component 4 and the arc-extinguishing chamber 2, and reduces the overall space required, thus improving the space utilization rate within the switch unit.

[0049] Furthermore, the combination of gas generation and electric arc not only accelerates the arc extinguishing process but also effectively reduces the thermal impact of the electric arc and hot airflow on the switching unit components, thereby extending the service life of the switching unit. The gas generated by the gas-generating component 4 continuously guides the flow of the electric arc and hot airflow, optimizing the arc segmentation process and making it easier to cool and suppress the arc and hot airflow. This design significantly enhances the breaking capacity of the switching unit, enabling it to maintain efficient and stable performance during frequent operation. Especially in high-frequency operating environments, the gas-generating component 4 enhances the cooling effect of the airflow, ensuring rapid arc extinguishing and meeting the high breaking capacity requirements of electrical equipment.

[0050] Optionally, such as Figures 2 to 4 As shown, the dimension along the thickness z of the housing at the end of the gas generating element 4 near the contact assembly 3 is larger than the dimension along the thickness z of the housing at the end of the gas generating element 4 near the arc-extinguishing chamber 2. This design gives the gas generating element 4 a gradually contracting shape, thereby better guiding the electric arc and hot airflow into the arc-extinguishing chamber 2. When the contact assembly 3 opens and generates an electric arc and hot airflow, this structural design of the gas generating element 4 can effectively control the flow direction of the electric arc and hot airflow through reasonable airflow guidance, ensuring that the electric arc and hot airflow can stably enter the arc-extinguishing chamber 2 without retreating in the opposite direction.

[0051] This design not only prevents arc retreat but also effectively reduces potential hazards caused by arc instability. Because the gas-generating element 4 is larger near the contact assembly 3, it generates a stronger airflow, rapidly guiding the arc and hot gas into the arc-extinguishing chamber 2, preventing them from remaining in the contact assembly 3 for too long or deviating from their intended path. Conversely, the smaller size near the arc-extinguishing chamber 2 helps to concentrate the generated gas along the path of the arc and hot gas flow, thus accelerating the cooling and extinguishing process. Through this gradually contracting design, the gas-generating element 4 not only effectively prevents arc retreat but also optimizes the flow path of the arc and hot gas into the arc-extinguishing chamber 2, allowing for more thorough cooling within the chamber.

[0052] Optionally, such as Figures 2 to 4 As shown, the inner side of the gas generating component 4 is connected to the arc-extinguishing chamber 2 via a plug-in connection. Simultaneously, the outer wall surface of the gas generating component 4, on the side facing away from the air inlet along the thickness direction z of the housing, is tightly fitted to the inner wall surface of the housing 1, improving installation stability. To ensure unobstructed airflow circulation, one or more first grooves 41 are designed on the outer wall surface of the gas generating component 4 on the side facing away from the air inlet along the thickness direction z of the housing. When the contact assembly 3 is tripped, the electric arc and hot airflow first enter the first channel from the air inlet and flow along the first channel to the second channel, then flow back into the first channel through the first groove 41 via the air inlet. The design of the first groove 41 helps to form a smooth airflow path, reduces the resistance to the flow of the electric arc and hot airflow, and further enhances the guiding effect of the airflow.

[0053] Optionally, such as Figure 5 and Figure 6 As shown, a first protrusion 11 is provided on the top wall of the housing 1, and the arc-extinguishing chamber 2 is sandwiched between the first protrusion 11 and the bottom wall, so that there is a gap between the arc-extinguishing chamber 2 and the top wall of the housing 1. Alternatively, a first protrusion 11 is provided on the bottom wall of the housing 1, and the arc-extinguishing chamber 2 is sandwiched between the first protrusion 11 and the top wall, so that there is a gap between the arc-extinguishing chamber 2 and the bottom wall of the housing 1. Or, opposing first protrusions 11 are provided on the top and bottom walls of the housing 1, and the arc-extinguishing chamber 2 is sandwiched between the opposing first protrusions 11, so that there are gaps between the arc-extinguishing chamber 2 and both the top and bottom walls of the housing 1. These designs allow the arc-extinguishing chamber 2 to be securely fixed inside the housing 1, while providing sufficient space between the arc-extinguishing chamber 2 and the top and / or bottom walls of the housing 1 to form an airflow circulation channel, further improving the arc-extinguishing effect.

[0054] Preferably, the arc-extinguishing chamber 2 is sandwiched between the opposing first protrusions 11, ensuring gaps between the arc-extinguishing chamber 2 and the top and bottom walls of the housing 1. This design not only ensures the stable installation of the arc-extinguishing chamber 2 but also provides two second channels for airflow. The first second channel is located between the arc-extinguishing chamber 2 and the top wall of the housing 1, while the other second channel is located between the arc-extinguishing chamber 2 and the bottom wall of the housing 1. Thus, the electric arc and hot airflow flowing out through the first channel are guided into these two second channels and then flow back to the first channel, forming a closed airflow circulation path. Through the synergistic effect of the two second channels, the electric arc and hot airflow obtain more cooling and extinguishing paths inside the arc-extinguishing chamber 2, allowing the cooling process of the electric arc and hot airflow to be fully extended, reducing temperature fluctuations in the electric arc, and improving the arc-extinguishing effect.

[0055] Optionally, such as Figure 7 and Figure 8 As shown, the contact assembly 3 includes a stationary contact 32 fixedly mounted on the housing 1 and a moving contact 31 rotatably mounted on the housing 1. A stationary contact piece 321 and an arc-inducing piece 322 are provided at the end of the stationary contact 32 closest to the moving contact 31. The stationary contact piece 321 cooperates with the moving contact 31 to perform closing or opening operations, ensuring the connection or disconnection of the circuit. Simultaneously, the arc-inducing piece 322 is designed to connect to the arc-extinguishing chamber 2, so that the electric arc and hot airflow generated when the moving contact 31 and stationary contact 32 are opened can be quickly captured and guided to the arc-extinguishing chamber 2 for processing. The arc-inducing piece 322 and the stationary contact 32 can be fixed together by screwing or riveting.

[0056] Specifically, the function of the arc-starting piece 322 is to ensure, through its connection with the arc-extinguishing chamber 2, that the electric arc does not spread or propagate irregularly within the switching unit at the moment of opening. Specifically, when the contacts open, an electric arc and hot airflow form between the moving and stationary contacts 32. The electric arc and hot airflow are rapidly guided to the arc-extinguishing chamber 2 by the arc-starting piece 322. The airflow and arc-extinguishing grid within the arc-extinguishing chamber 2 cut and cool the electric arc and hot airflow, thereby effectively preventing the spread of the electric arc within the switching unit and minimizing damage to internal components. The guiding path of the electric arc and hot airflow is optimized through the coordinated design of the arc-starting piece 322 and the arc-extinguishing chamber 2, ensuring that the electric arc and hot airflow can flow along a predetermined path, thereby accelerating the extinguishing of the electric arc.

[0057] Optionally, such as Figure 8 As shown, the arc-starting plate 322 includes a connecting portion 3221 and an arc-starting portion 3222 connected in sequence. The connecting portion 3221 contacts the stationary contact 321, and the arc-starting portion 3222 is connected to the arc-extinguishing chamber 2. Through this connection, the electric arc and hot gas flow can be rapidly transferred from the stationary contact 321 to the arc-starting plate 322 when the contacts are opened, and then guided to the arc-extinguishing chamber 2 for processing through the arc-starting portion 3222.

[0058] To optimize the arc guiding path, the end of the connecting portion 3221 near the arc-extinguishing chamber 2 is designed to be recessed within the end of the stationary contact 321 near the arc-extinguishing chamber 2, or flush with the end of the stationary contact 321 near the arc-extinguishing chamber 2. This design ensures that the arc and hot gas flow do not directly enter the arc-extinguishing chamber 2 along the connecting portion 3221, but instead enter the arc-extinguishing chamber 2 through the arc-initiating portion 3222 via a more stable path, thereby increasing the flow path of the arc and hot gas flow. This increased path allows the arc and hot gas flow to obtain more cooling opportunities during the flow process, reducing the temperature of the arc and hot gas flow and accelerating its extinction process. In addition, the arc-initiating portion 3222 can be designed as a zigzag shape to further extend the flow path of the arc and hot gas flow, avoiding turbulence or irregular propagation of the arc and hot gas flow within the arc-extinguishing chamber 2, ensuring that the arc and hot gas flow can enter the arc-extinguishing chamber 2 along a predetermined path, thereby improving the arc extinguishing efficiency.

[0059] Optionally, such as Figure 5 and Figure 6 As shown, to effectively solve the heat dissipation problem of the switching unit under high load and frequent operation, and to ensure the stability and reliability of the equipment during long-term operation, one or more heat dissipation slots 14 are provided on the housing 1. Specifically, the housing 1 consists of a base 12 and an end cover 13 that covers the base 12. A second protrusion 131 protruding towards the base 12 is provided on the inner wall of the end cover 13, and a corresponding second groove 121 is provided on the base 12. The second protrusion 131 is inserted into the second groove 121, so that the end cover 13 reliably covers the base 12. The combination of the base 12 and the end cover 13 forms a mounting cavity. This mounting cavity includes two parts: a first mounting cavity for mounting the arc-extinguishing chamber 2 and the contact assembly 3, and a second mounting cavity for mounting the mutually cooperating second protrusion 131 and second groove 121 to ensure a precise and stable fit between the base 12 and the end cover 13.

[0060] To improve heat dissipation efficiency, such as Figure 8 As shown, heat dissipation grooves 14 are formed on the side wall between the first and second mounting cavities, and on the outer side wall of the second mounting cavity. When the contact assembly 3 is opened, the hot air generated in the first mounting cavity flows through the heat dissipation grooves 14 on the side wall between the first and second mounting cavities to the second mounting cavity, and then flows out from the heat dissipation grooves 14 on the outer side wall of the second mounting cavity. At this time, the hot air exchanges heat with the outside air, carrying away the heat inside the switching unit, thereby effectively reducing the internal temperature and preventing overheating from affecting the performance and service life of the switching unit.

[0061] In summary, the design of the heat dissipation slot 14 ensures that heat inside the switching unit can be quickly dissipated and effectively cooled to the external environment. Especially under conditions of frequent operation or high load, the heat dissipation slot 14 allows heat to be carried away promptly through airflow, preventing overheating-related malfunctions or performance degradation. Furthermore, the heat dissipation slot 14 not only improves heat dissipation efficiency but also ensures stable operation of the equipment over extended periods under high-frequency operation, thereby enhancing the reliability and safety of the switching unit.

[0062] In another aspect of this application, a switch is provided, such as a circuit breaker, a changeover switch, or a disconnector switch. The switch includes a handle, an operating mechanism, and multiple switching units of any of the above. The handle is driven and connected to the moving contacts 31 of the multiple switching units via the operating mechanism, so as to drive the moving contacts 31 to close or open with the stationary contacts 32. Since the switch uses the aforementioned switching units, it also has the same beneficial effects as the switching units, which will not be described in detail here.

[0063] This application also provides a power distribution device, which is equipped with the aforementioned switch unit and / or switch. The power distribution device can be configured with at least one of the following: distribution box, cable, distribution cabinet, motor, switch socket, lamp, air conditioner, electric water heater, electricity meter, camera, telephone, computer, etc. Such power distribution devices can utilize the switch unit and / or switch-related structures of this application to achieve intelligent management, but are not limited to the above-mentioned intelligent management power distribution devices; they can also be used in non-intelligent power distribution devices in traditional industries.

[0064] This application also provides a power distribution device, which applies the aforementioned switch unit and / or switch to the power distribution device. The power distribution device can be used in smart scenarios, intelligent usage scenarios and the Internet of Things industry to achieve intelligent scenario-based management.

[0065] Optionally, the embodiments of this application can be used for: fire protection power supply: fire control room, fire pump, smoke prevention and exhaust system, fire elevator and its drainage pump, fire emergency lighting, etc. (Level 1); corridor lighting, duty lighting, guard lighting, obstacle marker lights; rail transit; security system power supply; electronic information computer room power supply; passenger elevator power supply; sewage pump; variable frequency speed regulation constant pressure water supply pump (otherwise it is a Level 2 load); main offices, conference rooms, general duty room, archives room.

[0066] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A switching unit, characterized in that, It includes a housing (1) and an arc-extinguishing chamber (2) and a contact assembly (3) installed in the housing (1). An air inlet is provided at one end of the arc-extinguishing chamber (2) near the contact assembly (3), and an air outlet is provided at one end of the arc-extinguishing chamber (2) away from the contact assembly (3). There is a gap between the inner wall of the housing (1) and the arc-extinguishing chamber (2). At least part of the electric arc generated when the contact assembly (3) is opened flows from the air outlet through the gap between the inner wall of the housing (1) and the arc-extinguishing chamber (2) to the air inlet.

2. The switching unit according to claim 1, characterized in that, The gap between the inner wall of the housing (1) and the arc-extinguishing chamber (2) together with the arc-extinguishing chamber (2) constitute the airflow circulation channel for at least part of the electric arc. The airflow circulation channel includes a first channel and a second channel connected in sequence. The first channel is the flow channel of the electric arc in the arc-extinguishing chamber (2). The second channel is the gap between the inner wall of the housing (1) and the outer wall of the arc-extinguishing chamber (2). The at least part of the electric arc first flows through the first channel to the second channel, and then flows through the second channel to the first channel.

3. The switching unit according to claim 2, characterized in that, A gas generating element (4) is provided at one end of the arc-extinguishing chamber (2) near the contact assembly (3). The gas generating element (4) is used to generate gas to drive the electric arc into the interior of the arc-extinguishing chamber (2) through the air inlet. The outer wall surface of the gas generating element (4) along the thickness direction (z) of the shell is flush with the outer wall surface of the arc-extinguishing chamber (2) along the thickness direction (z).

4. The switching unit according to claim 3, characterized in that, The dimension of the gas generating element (4) near the contact assembly (3) along the thickness direction (z) of the housing is greater than the dimension of the end of the gas generating element (4) near the arc extinguishing chamber (2) along the thickness direction (z).

5. The switching unit according to claim 3 or 4, characterized in that, At least one first groove (41) is provided on the outer wall surface of the gas generating component (4) on the side opposite to the air inlet along the thickness direction (z) of the housing. The electric arc flowing to the second channel flows to the first channel through the first groove (41).

6. The switching unit according to any one of claims 1 to 4, characterized in that, The top and / or bottom walls of the housing (1) are provided with opposing first protrusions (11), and the arc-extinguishing chamber (2) is sandwiched between the opposing first protrusions (11), between the first protrusions (11) and the top wall, or between the first protrusions (11) and the bottom wall, so that there is a gap between the arc-extinguishing chamber (2) and the top and / or bottom walls of the housing (1).

7. The switching unit according to any one of claims 1 to 4, characterized in that, The contact assembly (3) includes a stationary contact (32) and a moving contact (31) installed on the housing (1). A stationary contact piece (321) and an arc-starting piece (322) are provided at one end of the stationary contact (32) near the moving contact (31). The stationary contact piece (321) cooperates with the moving contact (31) to close or open the circuit. The arc-starting piece (322) is connected to the arc-extinguishing chamber (2). The arc-inducing plate (322) includes a connecting part (3221) and an arc-inducing part (3222) connected in sequence. The connecting part (3221) is connected to the stationary contact plate (321), and the arc-inducing part (3222) is connected to the arc-extinguishing chamber (2). The end of the connecting part (3221) near the arc-extinguishing chamber (2) is recessed into the end of the stationary contact plate (321) near the arc-extinguishing chamber (2).

8. The switching unit according to any one of claims 1 to 4, characterized in that, At least one heat dissipation groove (14) is provided on the housing (1).

9. The switching unit according to any one of claims 1 to 4, characterized in that, A first through hole (15) is provided on the housing (1) near the air outlet. When the contact assembly (3) is opened, part of the electric arc generated flows out of the housing (1) through the air inlet, the air outlet and the first through hole (15) in sequence.

10. A switch, characterized in that, It includes a handle, an operating mechanism, and a plurality of switch units as described in any one of claims 1 to 9, wherein the handle is driven and connected to the plurality of switch units via the operating mechanism.

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