An arc extinguishing chamber of a low voltage circuit breaker and a low voltage circuit breaker

Abstract

The utility model relates to a kind of arc-extinguishing chamber and low-voltage circuit breaker of low-voltage circuit breaker, comprising: shell, it is surrounded by sequentially connected first side plate, bent plate, second side plate and straight plate, bent plate has a bending piece;Arc-extinguishing grid group is equipped in shell;Top cover is equipped above shell;Insulating cover is equipped below shell, its side close to bent plate has a bending piece accommodating groove, bending piece is in bending piece accommodating groove;The side of insulating cover away from shell is inwardly concave arc plate, the height of the side of arc plate away from bending piece accommodating groove is lower than the height of the side of arc plate close to bending piece accommodating groove.The utility model has an inwardly concave arc plate, the arc plate is consistent with the movement track of moving contact, and arc can be quickly extinguished;The height of the side of arc plate away from bending piece accommodating groove is lower than the height of the side of arc plate close to bending piece accommodating groove, so that arc plate cooperates with short piece of contact system, arc produced by short contact piece is conveniently arc climbing, and air passage is left, to ensure internal pressure.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical equipment protection technology, specifically to an arc-extinguishing chamber for a low-voltage circuit breaker and a low-voltage circuit breaker. Background Technology

[0002] With the continuous development of the electricity market, the demand for operating voltage in industrial power systems is constantly increasing. However, the electric arc generated under extremely high voltage conditions is accompanied by extremely high temperatures, which can melt the plastic materials inside the circuit breaker in a short time, ultimately causing the circuit breaker to burn out and seriously affecting the safe and stable operation of the power system. To address this problem, the most direct improvement methods currently available in the industry are mainly two: one is to change the structural design of the arc-extinguishing grid to optimize the arc guiding path, making it easier for the arc to enter the arc-extinguishing grid; the other is to increase the thickness of the arc-extinguishing grid to reduce the temperature rise during the arc extinguishing process by increasing its heat capacity.

[0003] Patent CN222562611U discloses an arc-extinguishing chamber for a low-voltage circuit breaker, which adopts an arc-extinguishing grid structure, including a top cover 1, a pair of side plates 2, a bent plate 3 at one end of the pair of side plates, an arc-blocking cover 4 at the bottom of the pair of side plates, and arc-extinguishing plates 5 arrayed between the pair of side plates 2. The arc-extinguishing plates 5 and the bent plate 3 are metal grids, and the side plates 2 are made of insulating material. The arc-extinguishing plates 5 and the bent plate 3 are placed parallel to the side plates 2 perpendicular to them. When the circuit breaker performs opening and closing operations, the contact system generates an electric arc during the operation. Under the magnetic field and "air blowing" effect of the arc-extinguishing chamber, the electric arc enters the arc-extinguishing chamber, where the arc-extinguishing plates 5 divide and cool the arc. With the development of the electricity market, the requirements for the operating voltage of the power system are constantly increasing, and the electric arc generated by extremely high voltage can easily damage electrical components. However, in the above scheme, the arc-isolating shield and the contact side of the moving contact are straight plates. Because the moving contact rotates along an arc trajectory, the arc-isolating shield has poor coverage of the moving contact, resulting in poor insulation performance. Furthermore, there is a dead angle between the arc-isolating shield and the moving contact, causing the arc to flow to the dead angle and not enter the arc-extinguishing chamber, leading to internal melting. If non-metallic materials melt, small particles will adhere to the silver points of the contact plates, causing a short circuit. Small particles adhering to the moving space can cause jamming, and in severe cases, prevent the contact from opening and closing. Utility Model Content

[0004] The purpose of this utility model is to overcome at least one of the defects of the prior art and provide an arc-extinguishing chamber for a low-voltage circuit breaker and a low-voltage circuit breaker.

[0005] The objective of this utility model can be achieved through the following technical solutions:

[0006] One objective of this utility model is to provide an arc-extinguishing chamber for a low-voltage circuit breaker, comprising:

[0007] The housing is composed of a first side plate, a bent plate, a second side plate and a straight plate connected in sequence, wherein the bent plate has a bending piece;

[0008] Arc-quenching grid assembly installed inside the housing;

[0009] A top cover located on top of the housing;

[0010] An insulating cover located below the housing has a bending piece receiving groove on one side near the bending plate, with the bending piece located in the bending piece receiving groove; the side of the insulating cover away from the housing is an inwardly concave arc-shaped plate, and the height of the arc-shaped plate away from the bending piece receiving groove is lower than the height of the arc-shaped plate near the bending piece receiving groove.

[0011] Furthermore, the arc-extinguishing chamber also has multiple flame-extinguishing plates, which are located between the top cover and the arc-extinguishing grid plate group.

[0012] Furthermore, the arc-extinguishing grid assembly includes a first arc-extinguishing grid assembly and a second arc-extinguishing grid assembly, wherein the first arc-extinguishing grid assembly is divided into two groups and symmetrically distributed on both sides of the second arc-extinguishing grid assembly.

[0013] Furthermore, the arc-extinguishing grids in the first arc-extinguishing grid group are straight-plate type arc-extinguishing grids.

[0014] Furthermore, the arc-extinguishing grid in the second arc-extinguishing grid group is an inverted U-shaped arc-extinguishing grid, which extends into the insulating cover.

[0015] Furthermore, the arc-extinguishing chamber also has an air inlet and an air outlet.

[0016] Furthermore, the air inlet is formed on the side of the arc-shaped plate opposite to the bending piece receiving groove, and the air outlet is formed on the top cover.

[0017] Furthermore, the sidewalls of the insulating cover near the curved plate and away from the curved plate are inclined sidewalls from bottom to top and from inside to outside, so that the air inlet forms a Venturi pipe structure that is wider at the bottom and narrower at the top.

[0018] Furthermore, the top cover is provided with a gap vent, and there is a gap between the outer side of the bent plate and the circuit breaker housing. This gap serves as an exhaust channel, extending from the gap vent to the working space of the moving contact.

[0019] The second objective of this utility model is to provide a low-voltage circuit breaker, including the arc-extinguishing chamber as described above.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) This utility model provides an arc-extinguishing chamber for a low-voltage circuit breaker. The insulating cover of the arc-extinguishing chamber has an inwardly concave arc-shaped plate. This arc-shaped plate matches the movement trajectory of the moving contact, eliminating the dead angle between the arc-extinguishing cover and the moving contact in the prior art, enabling rapid arc extinguishing and thus reducing the damage of the circuit breaker to the arc. At the same time, the height of the side of the arc-shaped plate away from the bending plate receiving groove is lower than the height of the side of the arc-shaped plate near the bending plate receiving groove (i.e., the inclined design of the insulating cover), so that the arc-shaped plate can cooperate with the short contact piece, facilitating the arc creep of the short contact piece, and leaving an air passage to ensure internal pressure. Specifically, the insulating cover facilitates the directional flow of energy into the arc-extinguishing chamber. The insulating cover wraps around the pins of the arc-extinguishing grid, forming a wide air passage with the grid, which is conducive to the air blowing effect, allowing the arc to enter the arc-extinguishing chamber more quickly and be extinguished. The inclined design of the insulating cover is also to form an accelerating air passage, and the arc design is not only to avoid the moving contact. The inclined and curved designs are intended to better enclose the moving contact piece, enhance insulation, and facilitate the formation of air channels.

[0022] (2) This utility model provides an arc-extinguishing chamber for a low-voltage circuit breaker. The side wall of the insulating cover near the bent plate and the side wall away from the bent plate are inclined side walls from bottom to top and from inside to outside, so that the air inlet forms a Venturi pipe structure that is wider at the bottom and narrower at the top, which can enhance the air blowing effect and accelerate the arc cooling. The inverted U-shaped arc-extinguishing grid extends into the insulating cover to further expand the arc division range and reduce residual conductive material and residual heat.

[0023] (3) This utility model provides an arc-extinguishing chamber for a low-voltage circuit breaker. The air vent in the gap between the top cover of the arc-extinguishing chamber and the exhaust channel on the outside of the bent plate can quickly discharge the residual heat after arc extinguishing. The symmetrical grouping layout of the straight plate and inverted U-shaped arc-extinguishing grid plates ensures a reasonable gap between the arc-starting angle and the contact system within the limited internal space of the circuit breaker, avoiding insulation or operation failures. It also improves the arc-extinguishing efficiency by optimizing the arc guiding path, ultimately significantly enhancing the reliability of the circuit breaker protection and ensuring the safe and stable operation of the industrial power system.

[0024] (4) This utility model provides an arc-extinguishing chamber for a low-voltage circuit breaker. The second arc-extinguishing grid group of the arc-extinguishing chamber is composed of multiple arc-extinguishing grids. The multiple arc-shaped arc-extinguishing grids are arranged in sequence and the ends facing the arc plate of the insulating cover form a concave arc structure. The arc structure matches the arc trajectory of the arc plate of the insulating cover, making full use of the dead corner space. The magnetic field range formed by the grid can better surround the moving contact piece, increase the magnetic blow-out effect, and also allow the arc to quickly enter the arc-extinguishing chamber, thereby extinguishing the arc. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the arc-extinguishing chamber of the low-voltage circuit breaker in Example 1;

[0026] Figure 2This is an exploded view of the arc-extinguishing chamber of the low-voltage circuit breaker in Example 1;

[0027] Figure 3 This is a cross-sectional view of the low-voltage circuit breaker in Example 1;

[0028] Figure 4 This is a cross-sectional view of the insulating cover in Example 1;

[0029] Figure 5 This is a side view of the arc-extinguishing chamber of the low-voltage circuit breaker in Example 1;

[0030] Figure 6 This is a schematic diagram showing the connection between the arc-extinguishing chamber and the moving contact of the low-voltage circuit breaker in Example 1;

[0031] Figure 7 This is a schematic diagram showing the connection between the arc-extinguishing chamber and the moving contact of the low-voltage circuit breaker in Example 2;

[0032] The following are the labels in the diagram: 1. First side plate; 2. Second side plate; 3. Top cover; 4. First flame extinguishing plate; 5. Second flame extinguishing plate; 6. First arc extinguishing grid plate group; 7. Second arc extinguishing grid plate group; 8. Bending plate; 9. Insulating cover; 9-1. Bending plate receiving groove; 9-2. Arc plate; 10. Straight plate. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0034] Example 1

[0035] In existing technologies, a dead angle exists between the arc-extinguishing shield and the moving contact, causing the arc to flow to this dead angle instead of entering the arc-extinguishing chamber, resulting in internal melting. If non-metallic materials melt, small particles can adhere to the silver points of the contact pieces, causing a short circuit. Small particles adhering to the moving space can cause jamming, and in severe cases, prevent the circuit from opening and closing. To overcome this defect, this embodiment provides an arc-extinguishing chamber for a low-voltage circuit breaker, the specific structure of which is described in [details omitted]. Figure 1-6 It includes a shell, an arc-extinguishing grid assembly, a top cover 3, and an insulating cover 9;

[0036] The housing is composed of a first side plate 1, a bent plate 8, a second side plate 2, and a straight plate 10 connected in sequence. The bent plate 8 has a bent piece. The arc-extinguishing grid is arranged inside the housing. The top cover 3 is located above the housing 1. The insulating cover 9 is located below the housing 1. The side of the insulating cover 9 near the bent plate 8 has a bent piece receiving groove 9-1, and the bent piece is located in the bent piece receiving groove 9-1. The side of the insulating cover 9 away from the housing is an inwardly concave arc-shaped plate 9-2. The height of the side of the arc-shaped plate 9-2 away from the bent piece receiving groove 9-1 is lower than the height of the side of the arc-shaped plate 9-2 near the bent piece receiving groove 9-1. More specifically, the contact movement trajectory structure of the insulating cover 9 is arc-shaped, and the arc-shaped plate 9-2 matches the movement trajectory of the contact, eliminating the dead angle between the arc-extinguishing cover and the moving contact in the prior art, which can quickly extinguish the arc, thereby reducing the damage of the circuit breaker to the arc.

[0037] Meanwhile, the height of the side of the arc plate 9-2 away from the bending piece receiving groove 9-1 is lower than the height of the side of the arc plate 9-2 near the bending piece receiving groove 9-1, so that the arc plate 9-2 can cooperate with the short piece of the contact system, which facilitates the arc climbing generated by the short contact piece, and leaves an air passage to ensure internal pressure.

[0038] In other words, the insulating cover 9 facilitates the directional flow of energy into the arc-extinguishing chamber. The insulating cover 9 encloses the leads of the arc-extinguishing grid, forming a wide air channel with the grid, which is beneficial for the air blowing effect, allowing the arc to enter the arc-extinguishing chamber more quickly and extinguish it. The inclined design of the insulating cover is also to form an accelerating air channel, and the curved design is not only to avoid the moving contact. Both the inclined and curved designs are for better enclosing the moving contact piece, strengthening insulation, and forming the air channel.

[0039] In this embodiment, the arc-extinguishing chamber also has multiple flame-extinguishing plates, which are located between the top cover 3 and the arc-extinguishing grid assembly. Preferably, it has two superimposed first flame-extinguishing plates 4 and second flame-extinguishing plates 5.

[0040] In this embodiment, the arc extinguishing grid plate group includes a first arc extinguishing grid plate group 6 and a second arc extinguishing grid plate group 7. The first arc extinguishing grid plate group 6 is divided into two groups and symmetrically distributed on both sides of the second arc extinguishing grid plate group 7.

[0041] In this embodiment, the arc-extinguishing grid in the first arc-extinguishing grid group 6 is a straight-plate type arc-extinguishing grid.

[0042] In this embodiment, the arc-extinguishing grid in the second arc-extinguishing grid group 7 is an inverted U-shaped arc-extinguishing grid, which extends into the insulating cover 9.

[0043] In this embodiment, the arc-extinguishing chamber also has an air inlet and an air outlet. The air inlet is formed on the side of the arc-shaped plate 9-2 opposite to the bent plate receiving groove 9-1, and the air outlet is formed on the top cover 3. The side wall of the insulating cover 9 near the bent plate 8 and the side wall away from the bent plate 8 are inclined side walls from bottom to top and from inside to outside, so that the air inlet forms a Venturi tube structure that is wider at the bottom and narrower at the top, which can enhance the air blowing effect and accelerate the arc cooling. The inverted U-shaped arc-extinguishing grid extends into the insulating cover to further expand the arc segmentation range and reduce residual conductive material and residual heat.

[0044] In this embodiment, the top cover 3 has a gap vent, and a gap is provided between the outer side of the bent plate 8 and the circuit breaker housing. This gap serves as an exhaust channel, extending from the gap vent to the working space of the moving contact. Specifically, the gap vent on the top cover cooperates with the exhaust channel on the outer side of the bent plate 8 to quickly dissipate residual heat after arc extinguishing. The symmetrical grouping of the straight plate and inverted U-shaped arc extinguishing grids ensures a reasonable gap between the arc-starting angle and the contact system within the limited internal space of the circuit breaker, avoiding insulation or operational faults. It also improves arc extinguishing efficiency by optimizing the arc guiding path, ultimately significantly enhancing the reliability of the circuit breaker protection and ensuring the safe and stable operation of the industrial power system.

[0045] Example 2

[0046] This embodiment is basically the same as the structure of embodiment 1. The difference is that the second arc-extinguishing grid plate group 7 in this embodiment is composed of multiple arc-extinguishing grid plates. The multiple arc-shaped arc-extinguishing grid plates are arranged in sequence and the ends facing the arc plate 9-2 of the insulating cover 9 form an inwardly concave arc structure. This arc structure matches the arc trajectory of the arc plate 9-2 of the insulating cover 9, making full use of the dead corner space. The magnetic field range formed by the grid plate can better surround the moving contact plate, increase the magnetic blow-out effect, and also allow the arc to quickly enter the arc-extinguishing chamber, thereby extinguishing the arc.

[0047] Example 3

[0048] This embodiment describes a low-voltage circuit breaker, which includes an arc-extinguishing chamber as described in Embodiment 1.

[0049] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from its technical solution shall still fall within the protection scope of this utility model.

Claims

1. An arc-extinguishing chamber for a low-voltage circuit breaker, characterized in that, include: The shell is composed of a first side plate (1), a bent plate (8), a second side plate (2) and a straight plate (10) connected in sequence, wherein the bent plate (8) has a bent piece; An arc-quenching grid assembly is installed inside the housing; A top cover (3) is provided on top of the shell; An insulating cover (9) located below the housing has a bending piece receiving groove (9-1) on one side near the bending plate (8), and the bending piece is located in the bending piece receiving groove (9-1); the side of the insulating cover (9) away from the housing is an inwardly concave arc plate (9-2), and the height of the side of the arc plate (9-2) away from the bending piece receiving groove (9-1) is lower than the height of the side of the arc plate (9-2) near the bending piece receiving groove (9-1).

2. The arc-extinguishing chamber of a low-voltage circuit breaker according to claim 1, characterized in that, The arc-extinguishing chamber also has multiple flame-extinguishing plates, which are located between the top cover (3) and the arc-extinguishing grid plate group.

3. The arc-extinguishing chamber of a low-voltage circuit breaker according to claim 1, characterized in that, The arc extinguishing grid plate group includes a first arc extinguishing grid plate group (6) and a second arc extinguishing grid plate group (7). The first arc extinguishing grid plate group (6) is divided into two groups and symmetrically distributed on both sides of the second arc extinguishing grid plate group (7).

4. The arc-extinguishing chamber of a low-voltage circuit breaker according to claim 3, characterized in that, The arc extinguishing grid in the first arc extinguishing grid group (6) is a straight plate type arc extinguishing grid.

5. The arc-extinguishing chamber of a low-voltage circuit breaker according to claim 3, characterized in that, The arc-extinguishing grid in the second arc-extinguishing grid group (7) is an inverted U-shaped arc-extinguishing grid, which extends into the insulating cover (9).

6. The arc-extinguishing chamber of a low-voltage circuit breaker according to claim 3, characterized in that, The second arc-extinguishing grid plate group (7) consists of multiple arc-extinguishing grid plates. The multiple arc-extinguishing grid plates are arranged in sequence and the ends facing the arc plate (9-2) of the insulating cover (9) form an inwardly concave arc structure. The arc structure matches the arc trajectory of the arc plate (9-2) of the insulating cover (9).

7. The arc-extinguishing chamber of a low-voltage circuit breaker according to claim 1, characterized in that, The arc-extinguishing chamber also has an air inlet and an air outlet; the air inlet is formed on the side of the arc plate (9-2) away from the bending plate receiving groove (9-1), and the air outlet is formed on the top cover (3).

8. The arc-extinguishing chamber of a low-voltage circuit breaker according to claim 1, characterized in that, The insulating cover (9) has an inclined sidewall that runs from bottom to top and from inside to outside on the sidewalls near the bent plate (8) and away from the bent plate (8), so that the air inlet forms a Venturi pipe structure that is wider at the bottom and narrower at the top.

9. The arc-extinguishing chamber of a low-voltage circuit breaker according to claim 1, characterized in that, The top cover (3) has a gap vent hole, and there is a gap between the outer side of the bent plate (8) and the circuit breaker housing. This gap serves as an exhaust channel, extending from the gap vent hole to the working space of the moving contact.

10. A low-voltage circuit breaker, characterized in that, Includes the arc-extinguishing chamber as described in any one of claims 1-9.

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