Switching appliance

Abstract

The application relates to a switch electric appliance, which comprises a base, a contact assembly and an arc-extinguishing chamber assembly, the base comprises a first base and a second base which are connected to each other in a two-phase mode, the contact assembly is arranged on one side of the arc-extinguishing chamber assembly, the contact assembly comprises a moving contact assembly and a static contact assembly which realize the on or off of the switch electric appliance, the contact assembly and the arc-extinguishing chamber assembly are clamped between the first base and the second base, the first base and the second base are respectively provided with a first air guide channel and a second air guide channel which are mirror-symmetrical on the side vertical surfaces corresponding to the clamped arc-extinguishing chamber assembly, the first air guide channel and the second air guide channel extend to the side of the moving contact assembly in the off movement direction, so that the high-temperature gas generated due to the arc between the moving contact assembly and the static contact assembly is guided and the side of the arc-extinguishing grid sheet in the off movement direction of the moving contact assembly is preheated.

Description

Technical Field

[0001] This invention relates to a switching device, specifically to a switching device with optimized arc-extinguishing function. Background Technology

[0002] When a circuit breaker breaks, the initial distance between the moving and stationary contacts is small, while the electric field strength is high. This generates an electric arc between the moving and stationary contacts. If the arc is not extinguished, the circuit cannot be completely disconnected. Moreover, the arc temperature is very high, which can burn out equipment and cause serious accidents. Therefore, quickly and effectively extinguishing the arc generated when a circuit breaker breaks is one of the important functions of a circuit breaker.

[0003] When an electric arc is generated in a circuit breaker, the ablation of the gas-generating material by the arc often results in the production of a large amount of gas. The high-pressure, high-heat gas generated by the arc blows towards the arc-extinguishing chamber, which not only accelerates the arc's entry into the chamber and lengthens the arc, but also preheats the arc-extinguishing grid plates, reducing the resistance to the arc entering the grid plates. However, the arc-extinguishing grid plates are usually a long row structure covering the opening and closing stroke of the moving contact. In existing technology, when the high-pressure, high-heat gas generated by the arc is ejected during the breaking of the moving and stationary contacts, usually only the arc-extinguishing grid plates near the stationary contact are preheated, while the arc-extinguishing grid plates near the moving contact's breaking direction remain at a lower temperature. This is not conducive to the rapid entry of the arc into the arc-extinguishing grid plates and restricts the arc-extinguishing effect of the arc-extinguishing chamber. Summary of the Invention

[0004] Therefore, in view of the above problems, the present invention proposes a switch with optimized structure, which guides the high-temperature gas generated by the electric arc to the arc-extinguishing grid on the side of the moving contact's breaking motion direction by setting a gas guiding channel.

[0005] This invention is achieved using the following technical solution:

[0006] This invention proposes a switching device, including a base, a contact assembly, and an arc-extinguishing chamber assembly. The base includes two opposing first bases and a second base. The contact assembly is disposed on one side of the arc-extinguishing chamber assembly. The contact assembly includes a moving contact assembly and a stationary contact assembly for making the switching device connect or disconnect. The arc-extinguishing chamber includes an arc-extinguishing grid. The contact assembly and the arc-extinguishing chamber assembly are sandwiched between the first base and the second base. The first base and the second base have mirror-symmetrical first and second air guide channels on their respective side surfaces that sandwich the arc-extinguishing chamber assembly. The first and second air guide channels extend toward the side of the moving contact assembly in the direction of disconnection, so as to guide and preheat the arc-extinguishing grid on the side of the moving contact assembly in the direction of disconnection of the moving contact assembly.

[0007] In order to accelerate the airflow velocity, in one embodiment, the first air guide channel and the second air guide channel are preferably Laval nozzle channels with the channel diameter decreasing from large to small and then expanding outward from small to large.

[0008] In one embodiment, based on manufacturing and installation considerations, the first air guide channel and the second conductor channel are preferably channels recessed on the side surfaces of the first base and the second base respectively, which enclose the arc-extinguishing chamber assembly.

[0009] To prevent the rapid impact of gas from generating a shock wave at the bottom of the circuit breaker base and returning to the contact area, and to improve the insulation strength of the contact area and enhance the deionization capability, in one embodiment, the contact assembly is positioned above the arc-extinguishing chamber assembly, and the arc-extinguishing chamber assembly is positioned below the contact assembly. The termination positions of the first gas guide channel and the second conductor channel extend downward beyond the lowest end of the arc-extinguishing chamber assembly, so that the gas rushing out of the arc-extinguishing chamber assembly can flow back to the top of the arc-extinguishing chamber assembly through the first gas guide channel and the second conductor channel.

[0010] In one embodiment, the arc-extinguishing chamber assembly preferably includes a grid support, an arc-extinguishing grid, a first gas-generating baffle, and a second gas-generating baffle. The moving contact assembly includes a moving contact end, and the stationary contact assembly includes a stationary contact end. The switching of the electrical appliance is achieved by the movement of the moving contact end relative to the stationary contact end. A gap is provided between the first gas-generating baffle and the second gas-generating baffle for the moving contact end to pass through.

[0011] In order to increase the contact surface between the electric arc and the gas-generating baffle and to increase the creepage distance between the moving and stationary contacts, in one embodiment, it is preferable to provide at least one arc-shaped groove on each of the first gas-generating baffle and / or the second gas-generating baffle.

[0012] In order to enable the moving and stationary contacts to quickly repel each other when a fault current occurs, in one embodiment, the stationary contact assembly preferably has a U-shaped bending structure at the contact end that is relatively close to the moving contact assembly, so that the stationary contact and the moving contact assembly can form a conductive "S"-shaped current loop.

[0013] In order to accelerate the contact between the electric arc and the gas-generating baffle and improve the gas blowing arc extinguishing effect, in one embodiment, a U-shaped magnetizing block is preferably included. The magnetizing block is fixed to the contact end of the stationary contact assembly in a semi-enclosed manner so that when an electric arc is generated at the moving contact end and the stationary contact end, the magnetic field of the magnetizing block drives the direction of the electric arc to deflect.

[0014] In one embodiment, the preferred switching device is a circuit breaker.

[0015] The present invention has the following beneficial effects: The present invention provides a first air guide channel and a second air guide channel on the base on both sides of the arc-extinguishing chamber assembly. On the one hand, it can guide the hot gas when the moving and stationary contact assemblies break to the arc-extinguishing grid plate on one side of the moving contact breaking direction, which can better preheat the arc-extinguishing grid plate on that side, improve the thermal breakdown between the grid plates, reduce the resistance of the arc entering the arc-extinguishing grid plate, and thus greatly improve the arc-extinguishing effect of the arc-extinguishing chamber assembly. On the other hand, the first air guide channel and the second air guide channel are set above the base, without changing the overall structure of the arc-extinguishing chamber assembly, thus retaining the flexibility of the arc-extinguishing chamber assembly design. Attached Figure Description

[0016] Figure 1 This is an exploded view of the circuit breaker structure in the embodiment;

[0017] Figure 2 This is a schematic diagram of the arc-extinguishing chamber assembly in the embodiment;

[0018] Figure 3 This is a schematic diagram of the stationary contact assembly in the embodiment;

[0019] Figure 4 This is a schematic diagram of the second base and contact assembly in the embodiment (the moving contact assembly and the stationary contact assembly are in the connected state);

[0020] Figure 5 This is a front view of the circuit breaker in the embodiment (the first base is hidden for easier observation);

[0021] Figure 6 yes Figure 5 Sectional view at point AA. Detailed Implementation

[0022] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments and to explain the operating principles of the embodiments in conjunction with the relevant descriptions in the specification. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0023] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0024] See Figure 1As shown in the preferred embodiment of the present invention, a circuit breaker is provided, including a base and a contact assembly and an arc-extinguishing chamber assembly 5 mounted on the base. It also includes functional units such as an operating mechanism, a tripping mechanism, and a handle (not shown in the figure) to meet the basic functions of the circuit breaker. The circuit breaker base includes a first base 1 and a second base 2, which are joined together to form the circuit breaker housing. The contact assembly and the arc-extinguishing chamber assembly 5 are sandwiched between the first base 1 and the second base 2. The contact assembly further includes a moving contact assembly 4 and a stationary contact assembly 3, wherein the moving contact assembly 4 has a moving contact end, and the stationary contact assembly 3 has a stationary contact end. Contact or separation between the two is achieved by the movement of the moving contact end relative to the stationary contact end, thereby realizing the connection or disconnection of the circuit breaker. The arc-extinguishing chamber assembly 5 is used to extinguish the arc generated when the moving and stationary contact ends are disconnected. For ease of description, refer to [reference needed]. Figure 1 and Figure 5 In this embodiment, the following is defined:

[0025] The first base 1 is located in front of the second base 2, and the second base 2 is located behind the first base 1, that is, the Y and Y' directions in the figure are the front and rear directions respectively;

[0026] The contact assembly is positioned above the arc-extinguishing chamber assembly 5, and the arc-extinguishing chamber assembly 5 is positioned below the contact assembly, i.e., the Z and Z' directions in the figure are the up and down directions, respectively;

[0027] The arc-extinguishing chamber assembly 5 extends in the left-right direction, with X and X' directions shown in the figure representing the left and right directions, respectively.

[0028] like Figure 2The arc-extinguishing chamber assembly 5 includes a grid support 53, arc-extinguishing grids 54, a first gas-generating baffle 51, and a second gas-generating baffle 52. The grid support 53 has two opposing arc-extinguishing grids 54 arranged in a row in the left-right direction, sandwiched between the two grid supports 53. The first gas-generating baffle 51 and the second gas-generating baffle 52 are respectively fixedly installed on the upper ends of the two grid supports 53, and are mirror images of each other in the front-back direction. The moving contact assembly 4 includes a moving contact end 41. In this embodiment, the stationary contact assembly 3 is located to the right of the moving contact end 41. The moving contact end 41 swings in the left-right direction, thereby realizing the connection and disconnection of the circuit breaker. The moving contact end 41 is located between the first gas-generating baffle 51 and the second gas-generating baffle 52, forming a left-right extending gap 50 between the first gas-generating baffle 51 and the second gas-generating baffle 52 for the moving contact end 41 to pass through. The first gas-generating baffle 51 and the second gas-generating baffle 52 are both made of insulating gas-generating materials such as nylon, melamine, and PA46. When an electric arc is generated between the moving and stationary contact points, the electric arc burns through the first gas-generating baffle 51 and the second gas-generating baffle 52, generating a large amount of gas that propels the electric arc into the arc-extinguishing chamber. The arc-extinguishing grid 54 then cuts the electric arc to achieve the effect of gas blowing to extinguish the arc.

[0029] Furthermore, each of the first gas-producing baffle 51 and the second gas-producing baffle 52 is provided with eight arc-shaped extending grooves. Taking the first gas-producing baffle 51 as an example, see [link to relevant documentation]. Figure 2 The first gas-generating baffle 51 is provided with eight arc-shaped grooves 511. These arc-shaped grooves 511 can effectively increase the contact area between the electric arc and the first gas-generating baffle 51, thereby improving the gas-generating efficiency of the first gas-generating baffle 51 under the high temperature of the electric arc, effectively increasing the pressure in the arc-extinguishing chamber, and accelerating the drive of the electric arc into the arc-extinguishing chamber to achieve rapid arc extinguishing. At the same time, the arc-shaped grooves 511 can effectively increase the creepage distance between the moving and stationary contact ends, improving the insulation capability of the product after testing. In other embodiments, the number of the aforementioned arc-shaped grooves can be four, six, or other numbers, which can be determined according to the specifications of the actual product.

[0030] See Figure 3-4In this embodiment, the contact end of the stationary contact assembly 3, which is relatively close to the moving contact assembly 4, has a U-shaped bend structure. It is provided with a stationary contact end 31 that engages or disengages with the moving contact end 41. By designing the contact end of the stationary contact assembly 3 as a U-shaped bend structure, the moving and stationary contacts can form a conductive "S"-shaped current loop. The current directions at the moving contact end 41 and the stationary contact end 31 are opposite. If a large fault current occurs in the circuit, according to the laws of electromagnetism, the opposing currents cause the moving contact to generate a repulsive force, effectively limiting the current rise and achieving a highly efficient current limiting effect. A U-shaped magnetizing block 32 is also fixedly installed on the contact end of the stationary contact assembly 3. The U-shaped magnetizing block 32 semi-encloses the contact end of the stationary contact assembly 3, which can effectively enhance the magnetic flux near the stationary contact end 31. When an electric arc is generated between the moving contact end 41 and the stationary contact end 3, the high magnetic flux near the stationary contact end 31 generates a Lorentz force on the electric arc, causing the electric arc to deflect, strengthening the contact between the electric arc and the first gas generating baffle 51 or the second gas generating baffle 52, and improving the gas generating efficiency and arc extinguishing effect.

[0031] See Figure 4-5 At the front and rear sides of the arc-extinguishing chamber assembly 5, mirror-symmetrical first air guide channels (not shown due to angle issues) and second air guide channels are respectively provided on the side facades of the first base 1 and the second base 2 corresponding to the arc-extinguishing chamber assembly 5. Taking the second base 2 as an example, a second air guide channel 21 is provided on the second base 2. This second air guide channel 21 extends towards the side facing the direction of the breaking movement of the moving contact assembly 4 (e.g., Figure 4 When a short-circuit current occurs in the line, the moving contact 41 and the stationary contact 31 quickly repel each other. The electric arc ablates the left and right first gas-generating baffles 51 and second gas-generating baffles 52, generating a large amount of high-heat gas, thus forming a high-pressure zone in the contact area. Under the action of the first and second gas guiding channels 21, the high-pressure, high-heat gas in the contact area is guided by the first and second gas guiding channels 21 and can quickly transfer along the extension path of the first and second gas guiding channels 21 to one side of the moving contact assembly 4 in the direction of breaking movement. Figure 5When the moving and stationary contact assemblies disconnect from the conducting state, the arc-extinguishing grid in region P2, which is closer to the stationary contact assembly 3, is closer to the hot gas. When the gas is ejected from the contact area between the moving and stationary contact assemblies, the arc-extinguishing grid in region P2 can be preheated better and faster. However, the arc-extinguishing grid in region P1, which is farther away from the stationary contact assembly 3 and on the side of the moving contact assembly 4 in the direction of disconnection, is farther away from the hot gas and receives poor preheating. The resistance to the arc entering the arc-extinguishing grid in region P1 is very large. In the prior art, the arc can only enter the arc-extinguishing grid in region P1 after being ignited by the arc-starting plate. Therefore, the utilization effect of the arc-extinguishing grid in region P1 is not good in the prior art. In this embodiment, by setting up a first gas guide channel and a second gas guide channel 21, the hot gas during the breaking of the moving and stationary contact assembly is directed to the arc-extinguishing grid plate in the P1 region on one side of the moving contact breaking direction. This can better preheat the arc-extinguishing grid plate on that side, improve the thermal breakdown between the grid plates, reduce the resistance of the arc entering the arc-extinguishing grid plate 54, and thus greatly improve the arc-extinguishing effect of the arc-extinguishing chamber assembly 5.

[0032] In this preferred embodiment, the first and second air guide channels 21 first form a contracting channel with a decreasing diameter, and then an expanding channel with a decreasing diameter. This results in an overall Laval nozzle channel where the channel diameter decreases towards the center and then expands outwards. Thus, the first and second air guide channels 21 not only guide the airflow but also accelerate its velocity, further propelling the arc towards the arc-extinguishing grid and improving the arc-extinguishing effect. Furthermore, in this embodiment, the first and second air guide channels 21, serving as the Laval nozzle channel, are respectively located on the first base 1 and the second base 2, independent of the arc-extinguishing chamber assembly 5. The structure of the arc-extinguishing chamber assembly 5 (especially the arc-extinguishing grid) is not interfered with or affected by the first and second air guide channels 21, thus allowing for greater flexibility in the structural design of the arc-extinguishing chamber assembly 5.

[0033] See Figure 4-6In this embodiment, the first and second gas guiding channels 21 begin at the positions corresponding to the stationary contact assembly 3, and terminate downwards beyond the lowest point of the arc-extinguishing chamber assembly 5. When the gas rushes downwards out of the arc-extinguishing chamber assembly 5, it can flow back to the contact area at the upper end of the arc-extinguishing chamber assembly 5 through the first and second gas guiding channels 11 and 21. The circulating gas can further drive the arc towards the arc-extinguishing grid 54. Simultaneously, this embodiment forms a return path through the first and second gas guiding channels 11 and 21, preventing the gas from rapidly impacting the bottom of the circuit breaker base and causing shock wave reflection before returning to the contact area, thus slowing the arc's entry into the arc-extinguishing chamber and preventing reignition of the contact area in severe cases due to reverse arc movement. After cooling by the first base 1 and the second base 2, the gas circulating to the contact area returns to an insulating state, improving the insulation strength of the contact area and preventing back-side breakdown. Furthermore, the cooled gas entering the contact area effectively reduces the temperature of the contact area and enhances the local deionization capability. Furthermore, in this embodiment, the gas in the contact area is ejected obliquely downwards due to the arrangement of the first gas guide channel and the second gas guide channel 21, resulting in a longer gas flow path (compared to the form of vertical downward gas ejection in the prior art). After the gas flows back upwards, the gas at the upper end of the arc-extinguishing chamber assembly 5 has basically disappeared, so there will be no turbulence caused by the collision of upward and downward gas.

[0034] In this embodiment, the first air guide channel 11 and the second air guide channel 21 are channels recessed on the corresponding side surfaces of the arc-extinguishing chamber component 5 of the first base 1 and the second base 2, respectively. Thus, the first air guide channel 11 and the second air guide channel 21 can be integrally formed on the base by injection molding, making it easier to manufacture and assemble.

[0035] This embodiment uses a circuit breaker as an example to illustrate the technical effects of the contact assembly, arc-extinguishing chamber assembly 5, and base. In addition, the above-mentioned contact assembly, arc-extinguishing chamber assembly 5, and base can also be applied to other different types of switching devices. The switching device refers to the switching device defined in GB / T 5226.1-2019 / IEC60204-1:2016, that is, an electrical appliance used to connect or disconnect one or more circuit currents, and its specific component form can be a circuit breaker, relay, disconnector, etc.

[0036] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail made to the invention without departing from the spirit and scope of the invention as defined in the appended claims fall within the protection scope of the invention.

Claims

1. A switching device, comprising a base, a contact assembly, and an arc-extinguishing chamber assembly, wherein the base comprises two opposing first bases and a second base, the contact assembly is disposed on one side of the arc-extinguishing chamber assembly, the contact assembly includes a moving contact assembly and a stationary contact assembly for making the switching device connect or disconnect, the arc-extinguishing chamber includes an arc-extinguishing grid, and the contact assembly and the arc-extinguishing chamber assembly are sandwiched between the first base and the second base, characterized in that: The first base and the second base are respectively provided with a first air guide channel and a second air guide channel in a mirror symmetrical manner on the side surfaces corresponding to the arc-extinguishing chamber assembly. The first air guide channel and the second air guide channel extend toward the side of the moving contact assembly in the direction of breaking movement, so as to guide the high-temperature gas generated by the electric arc between the moving contact assembly and the stationary contact assembly and preheat the arc-extinguishing grid plate on the side of the moving contact assembly in the direction of breaking movement. The first air guide channel and the second conductor channel are channels formed by recesses on the side surfaces of the first base and the second base corresponding to the side surfaces of the arc-extinguishing chamber assembly.

2. The switching device according to claim 1, characterized in that: The first and second air guide channels are Laval nozzle channels whose diameter decreases from large to small and then expands outward.

3. The switching device according to claim 1, characterized in that: The contact assembly is positioned above the arc-extinguishing chamber assembly, and the arc-extinguishing chamber assembly is positioned below the contact assembly. The termination positions of the first gas guide channel and the second conductor channel extend downward beyond the lowest end of the arc-extinguishing chamber assembly, so that the gas rushing out of the arc-extinguishing chamber assembly can flow back to the top of the arc-extinguishing chamber assembly through the first gas guide channel and the second conductor channel.

4. The switching device according to claim 1, characterized in that: The arc-extinguishing chamber assembly includes a grid support, an arc-extinguishing grid, a first gas-generating baffle, and a second gas-generating baffle. The moving contact assembly includes a moving contact end, and the stationary contact assembly includes a stationary contact end. The switching of the electrical appliance is achieved by the movement of the moving contact end relative to the stationary contact end. There is a gap between the first gas-generating baffle and the second gas-generating baffle for the moving contact end to pass through.

5. The switching device according to claim 4, characterized in that: At least one arc-shaped groove is provided on each of the first gas-generating baffle and / or the second gas-generating baffle.

6. The switching device according to claim 5, characterized in that: The stationary contact assembly has a U-shaped bend at its contact end relative to the moving contact assembly, thereby enabling the stationary contact to form a conductive "S"-shaped current loop with the moving contact assembly.

7. The switching device according to claim 6, characterized in that: It also includes a U-shaped magnetizing block, which is fixed to the contact end of the stationary contact assembly in a semi-enclosed manner, so that when an electric arc is generated at the moving contact end and the stationary contact end, the magnetic field of the magnetizing block drives the direction of the electric arc to deflect.

8. The switching device according to any one of claims 1-7, characterized in that: The switching device mentioned is a circuit breaker.

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