Arc extinguish chamber of low-voltage circuit breaker

Abstract

The utility model belongs to the technical field of circuit breakers, and relates to an arc extinguishing chamber of a low-voltage circuit breaker, which comprises a shell, an air inlet arranged at the bottom of the shell, an air outlet arranged at the top of the shell, and a plurality of arc extinguishing grid sheets arranged between the air inlet and the air outlet in parallel, a first arc isolating cover and a second arc isolating cover are oppositely arranged on the inner walls of the two sides of the air inlet and are provided with inclined side walls from bottom to top and from inside to outside, so that the air inlet forms a Venturi pipeline structure with a wide lower part and a narrow upper part; the Venturi pipeline structure is used as a moving contact opening and closing receding groove. Compared with the prior art, the group of isolation hoods are oppositely arranged at the air inlet of the arc extinguish chamber, and the side walls of the isolation hoods are designed to be the inclined side walls which are inclined and extend inwards, so that the venturi pipeline which is narrow at the upper part and wide at the lower part is formed at the air inlet of the arc extinguish chamber, air flow is enabled to circulate quickly, and electric arcs are driven to enter the arc extinguish chamber quickly.

Description

Technical Field

[0001] The utility model belongs to the technical field of circuit breakers and relates to an arc extinguishing chamber of a low-voltage circuit breaker. Background Art

[0002] Low-voltage frame circuit breakers are large-capacity low-voltage electrical equipment, mainly used in industrial power systems to ensure normal circuit connection and disconnection, and automatically disconnect the circuit under abnormal circuit conditions (such as overload and short circuit).

[0003] like Figure 1 As shown, the arc extinguishing chamber of the low-voltage circuit breaker adopts an arc extinguishing grid structure, including a top cover 1 at the top, a pair of side panels 2 on both sides, a bent plate 3 at one end of the pair of side panels, an arc shield 4 at the bottom end of the pair of side panels, and arc extinguishing plates 5 arrayed between the pair of side panels 2. The arc extinguishing plates 5 and bent plates 3 are metal grids, the side panels 2 are made of insulating materials, and the arc extinguishing plates 5 and bent plates 3 are placed perpendicular to the side panels 2. When the circuit breaker performs opening and closing movements, the contact system generates an arc during the operation. Under the action of the magnetic field and "air blowing" of the arc extinguishing chamber, the arc enters the arc extinguishing chamber, and the arc extinguishing plates 5 divide and cool the arc. With the development of the power market, the requirements of the power system for the use voltage are constantly increasing, and the arc generated by extremely high voltages can easily damage electrical components.

[0004] The most direct method for decomposing the arc in the existing arc extinguishing chamber is to increase the number of arc extinguishing pieces 5, but this not only takes up a large space, but also cannot ensure that the arc will completely enter the arc extinguishing chamber, resulting in a reduction in the effect of the arc extinguishing piece 5, and the arc wreaks havoc inside the circuit breaker, which is easy to cause internal welding of the circuit breaker. At the same time, although the large-scale enclosed structure can reduce the arc spray phenomenon to a certain extent, it does not take into account that the internal pressure of the circuit breaker will damage the circuit breaker. Utility Model Content

[0005] The purpose of the utility model is to provide an arc extinguishing chamber of a low-voltage circuit breaker, which is used to quickly extinguish an electric arc so as to reduce the damage of the electric arc to the circuit breaker structure.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] An arc extinguishing chamber comprises a shell, an air inlet arranged at the bottom of the shell, an air outlet arranged at the top of the shell, and a plurality of arc extinguishing grids arranged in parallel between the air inlet and the air outlet;

[0008] A first arc shield and a second arc shield are disposed on the inner walls on both sides of the air inlet, and the first arc shield and the second arc shield have inclined side walls from bottom to top and from inside to outside, so that the air inlet forms a venturi pipe structure that is wide at the bottom and narrow at the top. The venturi tube effect is formed to increase the flow rate so that the arc quickly enters the arc extinguishing chamber and is extinguished;

[0009] The Venturi pipe structure is used as a clearance slot for the moving contact opening and closing.

[0010] Furthermore, a top cover is provided at the air outlet on the top of the shell, and a plurality of air holes are opened on the top cover.

[0011] Furthermore, a porous isolation sheet is laid inside the top cover.

[0012] Furthermore, the porous isolation sheet includes a first porous isolation sheet and a second porous isolation sheet which are arranged at an interval.

[0013] Furthermore, the shell includes a group of oppositely arranged side plates and a group of oppositely arranged bent plates and vertical plates;

[0014] The side plates, the bent plates and the vertical plates are combined to form a shell that penetrates from top to bottom.

[0015] Furthermore, a gap air hole is provided on the top cover, and a gap is provided between the outer side of the bent plate and the circuit breaker housing. The gap serves as an exhaust passage and extends from the gap air hole to the working space of the moving contact.

[0016] Furthermore, the arc extinguishing grid is perpendicular to the side plate, the bent plate includes a straight plate section and a bent plate section, the straight plate section and the vertical plate are parallel to the arc extinguishing grid, the bent plate section is bent toward the upper end of the Venturi pipe structure and is spaced apart from the moving contact.

[0017] Furthermore, a bending groove is provided on one side of the first arc isolation cover and the second arc isolation cover, and the bent plate section of the bent plate is embedded in the bending groove. A straight groove is provided on the side plate, and the straight plate section is embedded in the straight groove to fix the bent plate between the side plates.

[0018] Furthermore, the arc extinguishing grid comprises a straight arc extinguishing grid group and an inverted U-shaped arc extinguishing grid group, the straight arc extinguishing grid group is distributed on both sides of the inverted U-shaped arc extinguishing grid group, and the two ends of the inverted U-shaped arc extinguishing grid group extend into the first arc isolation cover and the second arc isolation cover respectively. The first arc isolation cover and the second arc isolation cover shield the arc extinguishing grid to maintain pressure.

[0019] Furthermore, both ends of the inverted U-shaped arc extinguishing grid group are lower than the moving contact, that is, to ensure that the silver point of the moving contact is always inside the first arc isolation cover and the second arc isolation cover during the opening and closing process, and is higher than the lowest point of the arc extinguishing plate 5-2 pin.

[0020] Furthermore, the first arc isolation cover and the second arc isolation cover are provided with rivet grooves, the side plates are provided with rivet holes, and the first arc isolation cover and the corresponding side plates, as well as the second arc isolation cover and the corresponding side plates are connected by rivets passing through the rivet holes and riveted to the rivet grooves.

[0021] Compared with the prior art, the utility model has the following beneficial effects:

[0022] 1) The utility model arranges a group of isolation covers relatively at the air inlet of the arc extinguishing chamber, and designs the side walls of the isolation covers to be inclined side walls extending inwardly, thereby forming a venturi duct that is narrow at the top and wide at the bottom at the air inlet of the arc extinguishing chamber, so that the air flow can circulate quickly, driving the arc to enter the arc extinguishing chamber faster.

[0023] 2) The utility model shields the lower end of the arc extinguishing grid by an isolation cover, and arranges a plurality of air holes connected with the inside of the circuit breaker near the air outlet of the arc extinguishing chamber, on the top cover and the side plate, so that the rising airflow is not hindered, thereby playing a role in maintaining pressure, stabilizing the internal pressure of the circuit breaker, reducing damage to the circuit breaker, and extending the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the interior of the arc extinguishing chamber of the utility model;

[0025] Figure 2 It is a partial schematic diagram of the arc extinguishing chamber of the utility model;

[0026] Figure 3 This is a schematic diagram of the arc extinguishing chamber of the utility model in a low voltage circuit breaker;

[0027] Figure 4 A schematic diagram of the connection of the arc extinguishing chamber grids of the utility model;

[0028] Description of the markings in the figure:

[0029] 1-top cover, 1-1-air hole, 1-2-screw hole, 1-3-side hole of top cover, 1-4-first porous isolation plate, 1-5-second porous isolation plate, 2-side plate, 2-1-riveting hole, 3-bent plate, 4-arc isolation cover, 4-1-first arc isolation cover, 4-2-second arc isolation cover, 5-arc extinguishing grid, 5-1-first straight plate type arc extinguishing grid group, 5-2-inverted U-shaped arc extinguishing grid group, 5-3-second straight plate type arc extinguishing grid group, 6-vertical plate. DETAILED DESCRIPTION

[0030] The following embodiments are implemented based on the above technical solution of the utility model, and provide detailed implementation methods and specific operation processes, but the protection scope of the utility model is not limited to the following embodiments.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0032] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0033] Example:

[0034] An arc extinguishing chamber is used to quickly extinguish an arc so as to reduce the damage of the arc to the circuit breaker structure. The structure includes a shell, an air inlet arranged at the bottom of the shell, an air outlet arranged at the top of the shell, and a plurality of arc extinguishing grids 5 arranged in parallel between the air inlet and the air outlet; a first arc isolation cover 4-1 and a second arc isolation cover 4-2 are arranged on the inner walls on both sides of the air inlet. The first arc isolation cover 4-1 and the second arc isolation cover 4-2 have inclined side walls from bottom to top and from inside to outside, so that the air inlet forms a Venturi pipe structure that is wide at the bottom and narrow at the top. The Venturi pipe structure is used as a clearance slot for the moving contact to open and close the switch. The Venturi tube effect is formed to increase the flow rate so that the arc quickly enters the arc extinguishing chamber and is extinguished.

[0035] In some specific embodiments, the shell includes a group of oppositely disposed side panels 2 and a group of oppositely disposed bent panels 3 and vertical panels 6; the side panels 2, the bent panels 3, and the vertical panels 6 together form a shell that is through-connected from top to bottom.

[0036] In some specific embodiments, the arc extinguishing grid 5 is perpendicular to the side plate 2, the bent plate 3 includes a straight plate section and a bent plate section, the straight plate section and the vertical plate 6 are parallel to the arc extinguishing grid 5, the bent plate section is bent toward the upper end of the Venturi pipe structure, and is spaced apart from the moving contact.

[0037] In some specific embodiments, a bending groove is provided on one side of the first arc isolation cover 4-1 and the second arc isolation cover 4-2, and the bent plate section of the bent plate 3 is embedded in the bending groove. A straight groove is provided on the side plate 2, and the straight plate section is embedded in the straight groove to fix the bent plate 3 between the side plates 2.

[0038] In some specific embodiments, the arc extinguishing grid 5 includes a straight arc extinguishing grid group and an inverted U-shaped arc extinguishing grid group 5-2, the straight arc extinguishing grid group is distributed on both sides of the inverted U-shaped arc extinguishing grid group, including a first straight arc extinguishing grid group 5-1 and a second straight arc extinguishing grid group 5-3, and both ends of the inverted U-shaped arc extinguishing grid group 5-3 extend into the first arc isolation cover 4-1 and the second arc isolation cover 4-2 respectively. The first arc isolation cover 4-1 and the second arc isolation cover 4-2 shield the arc extinguishing grid 5 to maintain pressure.

[0039] In some specific embodiments, both ends of the inverted U-shaped arc extinguishing grid group are lower than the moving contact, that is, to ensure that the silver point of the moving contact is always inside the first arc extinguishing cover 4-1 and the second arc extinguishing cover 4-2 during the opening and closing process, and is higher than the lowest point of the pin of the inverted U-shaped arc extinguishing plate 5-2.

[0040] In some specific embodiments, a plurality of ventilation holes are provided on the side plate 2 , and the ventilation holes are arranged opposite to the arc-extinguishing grid 5 at intervals.

[0041] In some specific embodiments, a rivet groove is provided on the first arc-isolating cover 4-1 and the second arc-isolating cover 4-2, and a rivet hole 2-1 is provided on the side plate 2. The first arc-isolating cover 4-1 and the corresponding side plate 2, and the second arc-isolating cover 4-2 and the corresponding side plate 2 are connected by rivets passing through the rivet holes 2-1 and riveted to the rivet grooves.

[0042] In some specific embodiments, a top cover 1 is provided at the gas outlet on the top of the housing, and a plurality of gap holes 1-1 are provided on the top cover 1 in addition to conventional gas outlet holes. A gap is provided between the outer side of the curved plate 3 of the arc extinguishing chamber and the circuit breaker housing, which can be set to 1-3 mm. The gap serves as an exhaust channel, extending from the gap holes 1-1 to the working space of the moving contact. The exhaust channel is used to maintain pressure and guide gas movement.

[0043] In some specific embodiments, a porous isolation sheet is laid inside the top cover 1. Preferably, the porous isolation sheet includes a first porous isolation sheet 1-4 and a second porous isolation sheet 1-5 which are arranged at intervals.

[0044] In some specific embodiments, the top cover 1 and the side panels 2 are connected by counter-screws at the side holes 1-3 of the top cover.

[0045] In some specific embodiments, the arc extinguishing chamber is installed in the circuit breaker as a whole through four screws at the screw holes 1 - 2 on the top cover 1 .

[0046] The above description of the embodiments is to facilitate the understanding and use of the utility model by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the utility model is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the utility model without departing from the scope of the utility model should be within the scope of protection of the utility model.

Claims

1. An arc extinguishing chamber, characterized in that: It comprises a shell, an air inlet arranged at the bottom of the shell, an air outlet arranged at the top of the shell, and a plurality of arc extinguishing grids (5) arranged in parallel between the air inlet and the air outlet; A first arc shield (4-1) and a second arc shield (4-2) are arranged on the inner walls on both sides of the air inlet, and the first arc shield (4-1) and the second arc shield (4-2) have inclined side walls from bottom to top and from inside to outside, so that the air inlet forms a venturi pipe structure that is wide at the bottom and narrow at the top; The Venturi pipe structure is used as a clearance slot for the moving contact opening and closing.

2. The arc extinguishing chamber according to claim 1, characterized in that: A top cover (1) is also provided at the air outlet on the top of the shell, and a plurality of air holes are provided on the top cover (1).

3. The arc extinguishing chamber according to claim 2, characterized in that: A porous isolation sheet is laid inside the top cover (1).

4. The arc extinguishing chamber according to claim 2, characterized in that: The housing comprises a group of side plates (2) arranged opposite to each other, a group of bent plates (3) and a vertical plate (6) arranged opposite to each other; The side plates (2), the bent plates (3) and the vertical plates (6) are combined to form a shell that penetrates from top to bottom.

5. The arc extinguishing chamber according to claim 4, characterized in that: The top cover (1) is provided with a gap air hole (1-1), and a gap is provided between the outer side of the bent plate (3) and the circuit breaker housing, the gap serving as an exhaust passage extending from the gap air hole (1-1) to the working space of the moving contact.

6. The arc extinguishing chamber according to claim 4, characterized in that: The arc extinguishing grid (5) is perpendicular to the side plate (2), the bent plate (3) comprises a straight plate section and a bent plate section, the straight plate section and the vertical plate (6) are parallel to the arc extinguishing grid (5), and the bent plate section is bent toward the upper end of the Venturi pipe structure and is spaced apart from the moving contact.

7. The arc extinguishing chamber according to claim 6, characterized in that: A bent groove is provided on one side of the first arc isolation cover (4-1) and the second arc isolation cover (4-2), and a bent plate section of the bent plate (3) is embedded in the bent groove. A straight groove is provided on the side plate (2), and the straight plate section is embedded in the straight groove, so as to fix the bent plate (3) between the side plates (2).

8. The arc extinguishing chamber according to claim 4, characterized in that: The arc extinguishing grid (5) comprises a straight arc extinguishing grid group and an inverted U-shaped arc extinguishing grid group, the straight arc extinguishing grid group is distributed on both sides of the inverted U-shaped arc extinguishing grid group, and the two ends of the inverted U-shaped arc extinguishing grid group extend into the first arc isolation cover (4-1) and the second arc isolation cover (4-2) respectively.

9. The arc extinguishing chamber according to claim 8, characterized in that: Both ends of the inverted U-shaped arc-extinguishing grid group are lower than the moving contact.

10. The arc extinguishing chamber according to claim 4, characterized in that: The first arc isolation cover (4-1) and the second arc isolation cover (4-2) are provided with riveting grooves, the side plate (2) is provided with riveting holes (2-1), and the first arc isolation cover (4-1) and the corresponding side plate (2), and the second arc isolation cover (4-2) and the corresponding side plate (2) are connected by rivets passing through the riveting holes (2-1) and riveted to the riveting grooves.

Images