An arc chute for a universal circuit breaker

Abstract

This utility model discloses an arc-extinguishing chamber for a universal circuit breaker. The arc-extinguishing chamber includes a base frame and a protective cover fixed on the base frame. The base frame contains an arc-splitting device and an arc-guiding plate. The protective cover has a pressure relief cover with several pressure relief holes. A primary baffle and a secondary baffle are installed inside the pressure relief cover, arranged in a staggered, layered manner. The primary and secondary baffles have several flow-blocking protrusions, which are staggered to extend the flow path of high-pressure gas carrying ionized particles. Each flow-blocking protrusion has a receiving recess. The receiving recess forms a particle interception barrier, and the staggered flow-blocking protrusions create a tortuous flow channel, extending the diffusion path of high-pressure gas and promoting particle collision and deposition. This structure effectively suppresses the escape of incandescent metal particles, avoiding the risk of insulation breakdown at the terminals and partial discharge from adjacent conductors, maintaining the electrical strength of the insulating medium, and ensuring the reliability of the equipment after an arc fault.

Description

Technical Field

[0001] This utility model relates to the field of circuit breaker technology, and in particular to an arc-extinguishing chamber for a universal circuit breaker. Background Technology

[0002] Universal circuit breakers are important electrical components in industrial and civil low-voltage power distribution equipment. They are mostly used as the main switch on the low-voltage side of the power distribution system to protect the power lines from overload and short-circuit faults. Among these functions, short-circuit fault protection is the most important. Because the short-circuit current in a line is very large during a short-circuit fault, a high-energy plasma arc is generated between the moving and stationary contacts when the circuit breaker interrupts the short-circuit current. Therefore, existing universal circuit breakers mostly use a large arc-extinguishing chamber to obtain a strong arc-extinguishing capability.

[0003] An arc-extinguishing chamber is designed to extinguish an electric arc. Based on the short-arc extinguishing principle, the arc-extinguishing chamber, made of thin steel plate and consisting of an arc-splitting grid, is placed above the contacts. When the contacts break the circuit, especially when breaking a short-circuit current, an arc current is generated between the contacts. Driven by electrodynamics and gas effects, the arc current enters the arc-splitting grid. The arc-splitting grid divides the arc into several short arcs in series. Under the near-cathode effect, the arc voltage is greater than the interrupted voltage and is difficult to maintain. At the same time, the arc-splitting grid absorbs the arc heat, causing the arc to cool down rapidly and extinguish.

[0004] However, the arc-extinguishing chamber inside the circuit breaker alone cannot completely and reliably extinguish the arc. Residual arc particles will be ejected along the gas duct towards the circuit breaker's terminals, carrying with them a large number of incandescent metal particles. These particles, following the arc, will directly pierce the circuit breaker's terminal baffles, fly outside the circuit breaker, and damage the insulation at the terminals. The incandescent metal particles will also splash onto the insulation of nearby conductors, reducing their insulation performance. Therefore, the applicant has developed a beneficial design and found a solution to the above problems. The technical solution described below arose from this context. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the arc-extinguishing chamber design of traditional universal circuit breakers and to provide a product that blocks the ejection of hot metal particles, slows down the flow of high-pressure gas, and has good safety.

[0006] To solve the above problems, the present invention adopts the following technical solution.

[0007] An arc-extinguishing chamber for a universal circuit breaker includes a base frame and a protective cover fixed to the base frame. The base frame contains an arc-splitting device and an arc-guiding plate. The protective cover has a pressure relief cover with several pressure relief holes. A primary baffle and a secondary baffle are installed inside the pressure relief cover, arranged at a distance and stacked. The primary and secondary baffles have several flow-blocking protrusions, which are staggered to extend the flow path of high-pressure gas carrying ionized particles. Each flow-blocking protrusion has a receiving recess to intercept incandescent metal particles. Both sides of the receiving recess have through-holes for reducing pressure and slowing gas flow.

[0008] Preferably, the arc-splitting device comprises stacked arc-splitting grids arranged in parallel transversely at equal intervals.

[0009] Preferably, permanent magnets are fixed on both sides of the inner wall of the base frame and adjacent to the arc guide plate, and the base frame is provided with a lateral pressure relief channel.

[0010] Preferably, the protective cover is provided with an air collecting cavity, the air collecting cavity is provided with a first through hole and a corresponding lateral pressure relief channel, the top of the air collecting cavity is provided with a padding layer, the padding layer is provided with a second through hole and a corresponding first through hole, the protective cover and the padding layer are provided with positioning blocks, and the padding layer is connected and fixed to the protective cover by screws.

[0011] Preferably, the primary baffle is fixed to the gas collecting cavity by screws, and the secondary baffle is fixed to the padding layer by screws.

[0012] Preferably, the inlet of the accommodating recess is provided with a guide slope.

[0013] Preferably, the pressure relief cover is fixed to the protective cover by screws and abuts against the pad layer and the pressure relief cover. The bottom surface of the pressure relief cover is provided with a positioning groove, and the positioning block is embedded in the positioning groove.

[0014] Beneficial effects:

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] (1) This utility model forms a directional blocking barrier through the structure of the recessed portion, which can effectively intercept the outflow of hot metal particles generated during the arc extinguishing process, avoid the particles directly impacting the terminal baffle of the circuit breaker and causing insulation breakdown, and at the same time prevent particles from adhering to the insulation surface of adjacent wires and causing the risk of partial discharge. This structure maintains the electrical strength of the insulation medium in the wiring area by limiting the particle diffusion path, and ensures the insulation integrity of the equipment after an arc fault.

[0017] (2) This utility model forms a tortuous flow channel by staggered flow-blocking protrusions, which prolongs the diffusion path of high-pressure gas in the arc-extinguishing chamber, increases the fluid viscosity resistance and promotes heat exchange between the gas and the wall. This structure forces some incandescent metal particles to collide and deposit with the primary baffle and the secondary baffle. The remaining particles lose their ability to disperse over long distances due to the attenuation of gas kinetic energy. By suppressing the particle migration rate, the risk of thermal damage or insulation failure of the internal insulation surface and adjacent conductors of the circuit breaker is effectively reduced, thereby improving the operational reliability of the equipment after the fault is disconnected. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the arc-extinguishing chamber of a universal circuit breaker according to this utility model;

[0019] Figure 2 This is a side cross-sectional view of the arc-extinguishing chamber of a universal circuit breaker according to the present invention.

[0020] Figure 3 This is an exploded view of the arc-extinguishing chamber of a universal circuit breaker according to this utility model;

[0021] Figure 4 This is a partially enlarged side cross-sectional view of the arc-extinguishing chamber of a universal circuit breaker according to this utility model;

[0022] The correspondence between the labels and component names in the attached figures is as follows:

[0023] Reference numerals: 1. Base frame; 2. Protective cover; 3. Pressure relief cover; 4. Primary baffle; 5. Secondary baffle; 6. Flow-blocking boss; 11. Arc-splitting device; 12. Arc guide plate; 13. Permanent magnet; 14. Pressure relief channel; 111. Arc-splitting grid group; 21. Gas collection cavity; 22. First through-flow hole; 23. Pad height; 24. Second through-flow hole; 25. Positioning block; 31. Pressure relief hole; 32. Positioning groove; 61. Accommodating recess; 62. Through-flow hole; 63. Flow guide slope. Detailed Implementation

[0024] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0026] Reference example Figures 1 to 4 An arc-extinguishing chamber for a universal circuit breaker includes a base frame 1 and a protective cover 2 fixed on the base frame 1. The base frame 1 is equipped with an arc-splitting device 11 and an arc-guiding plate 12. The protective cover 2 is equipped with a pressure relief cover 3, which has several pressure relief holes 31. The pressure relief cover 3 is equipped with a primary baffle 4 and a secondary baffle 5, which are spaced apart and stacked. The primary baffle 4 and the secondary baffle 5 are equipped with several flow-blocking protrusions 6, and the flow-blocking protrusions 6 of the two baffles are staggered to extend the flow path of high-pressure gas carrying ionized particles. The flow-blocking protrusions 6 have accommodating recesses 61 to intercept incandescent metal particles. The accommodating recesses 61 have through-holes 62 on both sides to reduce pressure and slow down the gas flow rate.

[0027] It is worth mentioning that the arc-splitting device 11 includes a stacked arc-splitting grid group 111 arranged in parallel and transversely at equal intervals. When the moving contact and the stationary contact are separated, an arc current is generated between the contacts. Driven by the electrodynamic force and the gas effect, the arc current enters the arc-splitting grid group 111. The arc-splitting grid group 111 divides the arc into several short arcs in series. Under the action of the near-cathode effect, the arc voltage is greater than the interrupted voltage and is difficult to maintain. At the same time, the arc-splitting grid group 111 absorbs the arc heat, causing the arc to cool down and extinguish rapidly.

[0028] It is worth mentioning that permanent magnets 13 are fixed on both sides of the inner wall of the base frame 1 and adjacent to the arc guide plate 12. The base frame 1 has a lateral pressure relief channel 14. Since the arc grid group 111 and the arc guide plate 12 are made of magnetic metal material, their magnetism will decay. In the later working process, the effect of adsorbing free metal ions will also continuously weaken. Therefore, in order to prevent the arc ignition effect of the arc guide plate 12 from decreasing with the working time, permanent magnets 13 are added to improve the arc ignition capability.

[0029] It is worth mentioning that the protective cover 2 is provided with a gas collecting cavity 21, the gas collecting cavity 21 is provided with a first through hole 22 and a corresponding lateral pressure relief channel 14, the top of the gas collecting cavity 21 is provided with a pad 23, the pad 23 is provided with a second through hole 24 and a corresponding first through hole 22, the protective cover 2 and the pad 23 are provided with positioning blocks 25, the pad 23 is connected and fixed to the protective cover 2 by screws, the gas collecting cavity 21 provides a space for the primary baffle 4, the pressure relief channel 14, the first through hole 22, and the second through hole 24 all serve to facilitate the passage of high pressure gas generated during arc interruption carrying hot metal particles, the pad 23 keeps the primary baffle 4 and the secondary baffle 5 at a distance, and increases the flow distance of high pressure gas, the positioning block 25 is used in conjunction with the positioning groove 32, and the pad 23 can be easily separated from the protective cover 2 by screw fixing, which is convenient for replacing the primary baffle 4 in the gas collecting cavity 21;

[0030] It is worth mentioning that the primary baffle 4 is fixed to the gas collecting cavity 21 by screws, and the secondary baffle 5 is fixed to the pad layer 23 by screws. The primary baffle 4 and the secondary baffle 5 can be easily replaced by fixing them with screws.

[0031] It is worth mentioning that a guide slope 63 is provided at the entrance of the receiving recess 61, which guides the high-pressure gas and hot metal particles into the receiving recess 61.

[0032] It is worth mentioning that the pressure relief cover 3 is fixed to the protective cover 2 by screws and abuts against the pad height 23 and the pressure relief cover 3. The bottom surface of the pressure relief cover 3 is provided with a positioning groove 32, and the positioning block 25 is embedded in the positioning groove 32. The pressure relief cover 3 is easily disassembled by fixing it with screws, so as to replace the primary baffle 4 and secondary baffle 5 inside the pressure relief cover 3. The positioning block 25 cooperates with the positioning groove 32 to improve the connection and sealing between the pressure relief cover 3 and the protective cover 2 and the pad height 23.

[0033] The working principle of this utility model is described as follows:

[0034] When the moving contact and stationary contact of the universal circuit breaker separate, an electric arc is generated at the moment of separation. The arc is guided into the arc-splitting device 11 by the arc guide plate 12 and the permanent magnet 13. Driven by electrodynamic force and gas effect, the arc enters the arc-splitting grid group 111. The arc-splitting grid group 111 divides the arc into several short arcs in series. Under the effect of near-cathode effect, the arc voltage is greater than the interrupted voltage and is difficult to maintain. At the same time, the arc-splitting grid group 111 absorbs the arc heat, so that the arc cools down and extinguishes rapidly.

[0035] When the arc-splitting grid group 111 cannot reliably extinguish all arcs, the residual arc will enter the gas collecting cavity 21 through the pressure relief channel 14 and the first through-flow hole 22. The high-pressure gas carrying some incandescent metal particles will first impact the primary baffle 4, and then the high-pressure gas will enter the receiving cavity 61. The receiving cavity 61 of the primary baffle 4 blocks most of the incandescent metal particles. Then, the high-pressure gas will be discharged through the venting hole 62 and enter the receiving cavity 61 of the secondary baffle 5 through the second through-flow hole 24. The secondary baffle 5 and its recess block the remaining incandescent metal particles, and enter the pressure relief cover 3 through the venting hole 62 of the receiving cavity 61 of the secondary baffle 5, and be discharged to the outside through the pressure relief hole 31. By making the high-pressure gas bend multiple times, the flow velocity of the high-pressure gas is greatly reduced and the creepage distance of the residual arc is extended, thereby extinguishing the residual arc.

[0036] The above design scheme enables the product to achieve the advantages of blocking the flight of hot metal particles, slowing down the flow rate of high-pressure gas, and ensuring good safety.

[0037] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present utility model. It should not be construed that the specific implementation of the present utility model is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present utility model, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted by the present utility model.

Claims

1. An arc-extinguishing chamber of a universal circuit breaker, comprising a base frame (1) and a protective cover (2) fixed on the base frame (1), wherein the base frame (1) is provided with an arc-splitting device (11) and an arc-guiding plate (12), and the protective cover (2) is provided with a pressure relief cover (3) having a plurality of pressure relief holes (31), characterized in that: The pressure relief cover (3) is equipped with a primary baffle (4) and a secondary baffle (5), which are spaced apart and stacked. The primary baffle (4) and the secondary baffle (5) are provided with several flow-blocking protrusions (6), and the flow-blocking protrusions (6) of the two baffles are staggered to extend the flow path of the high-pressure gas carrying ionized particles. The flow-blocking protrusion (6) has a receiving recess (61) for intercepting hot metal particles; The accommodating recess (61) has through holes (62) on both sides for reducing pressure and slowing down gas flow.

2. The arc-extinguishing chamber of the universal circuit breaker according to claim 1, characterized in that: The arc-splitting device (11) includes stacked arc-splitting grids (111) arranged in parallel transversely at equal intervals.

3. The arc-extinguishing chamber of the universal circuit breaker according to claim 1, characterized in that: The base frame (1) has permanent magnets (13) fixed on both sides of its inner wall and adjacent to the arc guide plate (12). The base frame (1) has a lateral pressure relief channel (14).

4. The arc-extinguishing chamber of the universal circuit breaker according to claim 3, characterized in that: The protective cover (2) is provided with a gas collecting cavity (21), the gas collecting cavity (21) is provided with a first through hole (22) and a corresponding lateral pressure relief channel (14), the top of the gas collecting cavity (21) is provided with a padding layer (23), the padding layer (23) is provided with a second through hole (24) and a corresponding first through hole (22), the protective cover (2) and the padding layer (23) are provided with positioning blocks (25), and the padding layer (23) is connected and fixed to the protective cover (2) by screws.

5. The arc-extinguishing chamber of the universal circuit breaker according to claim 4, characterized in that: The primary baffle (4) is fixed to the gas collecting cavity (21) by screws, and the secondary baffle (5) is fixed to the padding layer (23) by screws.

6. The arc-extinguishing chamber of the universal circuit breaker according to claim 5, characterized in that: The inlet of the accommodating recess (61) is provided with a guide slope (63).

7. The arc-extinguishing chamber of the universal circuit breaker according to claim 4, characterized in that: The pressure relief cover (3) is fixed to the protective cover (2) by screws and abuts against the pad layer (23) and the pressure relief cover (3). The bottom surface of the pressure relief cover (3) is provided with a positioning groove (32), and the positioning block (25) is embedded in the positioning groove (32).

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