Separate arc extinguishing chamber of circuit breaker

Abstract

The present invention relates to the technical field of circuit breakers, and discloses a separate arc extinguishing chamber of a circuit breaker, wherein the arc extinguishing chamber is arranged inside a plastic shell, a static contact and a moving contact are arranged inside the plastic shell, a swinging partition is rotatably installed inside the arc extinguishing chamber, the moving contact is fixedly connected to the swinging partition, the static contact is fixedly installed inside the plastic shell, a separate arc extinguishing grid assembly is installed inside the arc extinguishing chamber, and the separate arc extinguishing grid assembly is arranged in the area between the static contact and the swinging partition. The arc extinguishing chamber is provided with a separate arc extinguishing grid assembly, and each arc extinguishing grid piece in the separate arc extinguishing grid assembly is arranged in a separate manner. When the moving contact and the static contact are disconnected to generate an arc, the spacing between each arc extinguishing grid piece increases rapidly from a small one, and while cutting a long arc into a short arc, the short arc is arced, and the thick arc is divided into a thin one. The air resistance in the gap between adjacent arc extinguishing grid pieces increases with the increase of the gap spacing, so that the arc voltage on each gap is reduced, thereby prompting the arc to be extinguished quickly.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and in particular to a separate arc extinguishing chamber of a circuit breaker. Background Art

[0002] The arc extinguishing performance of a circuit breaker directly affects the breaking capacity and service life of the circuit breaker. There are various arc extinguishing methods for circuit breakers, each of which has its advantages, disadvantages and applicable scope. The arc extinguishing method of the arc extinguishing grid is widely used in low-voltage circuit breakers (air switches). For example, in the prior art, the patent document with announcement number CN108269709B discloses an arc extinguishing chamber of a circuit breaker, which is arranged on one side of the contact mechanism of the circuit breaker, including a mounting bracket, a first grid group and a second grid group. The first grid group and the second grid group are installed on the mounting bracket one above and one below along the closing direction of the contact mechanism. The first grid group includes a plurality of longitudinal grids arranged at intervals, and the second grid group includes a plurality of transverse grids arranged at intervals; and the first longitudinal grid farthest from the contact mechanism in the first grid group is connected and conductive with the first transverse grid closest to the first grid group in the second grid group. The invention provides an arc extinguishing chamber of a circuit breaker, which is provided with two grid groups arranged horizontally and vertically, and the longitudinal grid farthest from the moving contact in the grid group arranged opposite to the moving contact and the transverse grid farthest from the static contact in the grid group arranged opposite to the static contact are connected and conducted, so as to reasonably guide the direction of the arc, maximize the lengthening of the arc, and achieve the effect of rapid and complete arc extinguishing.

[0003] By increasing the number of arc-extinguishing grids, although a long arc can be divided into more short arcs, in a limited space, the number of arc-extinguishing grids increases and the gaps between them decrease, resulting in an increase in air resistance. Under the action of hot air flow, the arc in the air cannot quickly enter the arc-extinguishing grid, and the delayed arc causes greater damage. If the gaps between the arc-extinguishing grids are increased, the number of arc-extinguishing grids will be reduced, which is not conducive to cutting multiple short arcs and has a poor arc extinguishing effect. Based on this, the arc-extinguishing chamber structure of the existing circuit breaker has the problem of being not conducive to rapid arc extinguishing, generating high temperature to damage its internal mechanism, and seriously affecting the safe use of the circuit breaker. Summary of the invention

[0004] The purpose of the present invention is to solve the defect that the arc extinguishing chamber structure of the existing circuit breaker is not conducive to rapid arc extinguishing, and to propose a separate arc extinguishing chamber of the circuit breaker.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a separate arc extinguishing chamber of a circuit breaker, the arc extinguishing chamber is arranged inside a plastic shell, a static contact and a moving contact are arranged inside the plastic shell, a swinging partition is rotatably installed inside the arc extinguishing chamber, the moving contact is fixedly connected to the swinging partition, the static contact is fixedly installed in the plastic shell, a separate arc extinguishing grid assembly is installed in the arc extinguishing chamber, and the separate arc extinguishing grid assembly is arranged in the area between the static contact and the swinging partition.

[0006] The separate arc extinguishing grid assembly includes multiple arc extinguishing grids. When the moving contact contacts the stationary contact, the swing partition provides a force for the arc extinguishing grids to reduce the gap between the arc extinguishing grids. When the moving contact is separated from the stationary contact, the gap between the arc extinguishing grids gradually increases. When extinguishing the arc, the spacing between the arc extinguishing grids increases rapidly from a small distance, cutting the long arc into short arcs while stretching the short arc, dividing the coarse arc into fine arcs, reducing the arc voltage on each gap, and thus prompting the arc to be extinguished quickly.

[0007] Preferably, the separate arc-extinguishing grid assembly includes a mounting base and a transmission plate, the top ends of a plurality of arc-extinguishing grids are rotatably connected to the mounting base, and the plurality of arc-extinguishing grids are arranged in parallel, and connecting shafts are fixedly installed on both sides of each arc-extinguishing grid, and each arc-extinguishing grid is rotatably connected to the transmission plate through the connecting shaft, so that the plurality of parallel arc-extinguishing grids are flipped synchronously, and the spacing between the arc-extinguishing grids is increased, thereby reducing their conductivity.

[0008] Preferably, a first magnetic block is fixedly installed on the surface of the swinging partition, and a second magnetic block is fixedly installed on the surface of the arc extinguishing grid close to the swinging partition. The acting force is the magnetic repulsion of the first magnetic block and the second magnetic block. A third magnetic block is fixedly installed on the inner wall of the arc extinguishing chamber, and a fourth magnetic block is fixedly installed on the surface of the arc extinguishing grid away from the swinging partition. The third magnetic block and the fourth magnetic block repel each other. Under the action of the magnetic repulsion of the first magnetic block and the second magnetic block, when the moving contact contacts the static contact, the arc extinguishing grid is tilted to reduce the gap of the arc extinguishing grid. Under the action of the third magnetic block and the fourth magnetic block, when the moving contact is separated from the static contact, the arc extinguishing grid can be flipped to a vertical state. The non-contact design reduces its impact damage.

[0009] Preferably, a connecting block is fixedly installed inside the arc extinguishing chamber, the upper side of the swinging partition is rotatably connected to the connecting block, the lower side of the swinging partition is in sliding contact with the inner wall of the arc extinguishing chamber, the swinging partition divides the inner cavity of the arc extinguishing chamber into an air pressure chamber and an arc extinguishing chamber, an arc striking window is opened on the inner wall of the arc extinguishing chamber, the static contact is fixed on the outside of the arc striking window, the static contact is connected with the arc extinguishing chamber through the arc striking window, a separate arc extinguishing grid assembly is arranged in the arc extinguishing chamber, the swinging partition is flipped synchronously with the moving contact, the swinging partition compresses the air in the air pressure chamber, or creates negative pressure for the air pressure chamber, so that the air pressure chamber has the function of blowing and sucking.

[0010] Preferably, a first exhaust channel is provided on the surface of the swing partition, and the air pressure chamber is connected to the arc extinguishing chamber through the first exhaust channel. The air in the air pressure chamber is compressed, and the compressed air is injected into the arc extinguishing chamber through the first exhaust channel, accelerating the arc and hot air flow into the gap of the arc extinguishing grid, and forming a negative pressure in the air pressure chamber to suck the air in the arc extinguishing chamber into the air pressure chamber, so that the outside air can enter the arc extinguishing chamber to achieve cooling and heat dissipation.

[0011] Preferably, one end of the mounting substrate is in contact with the connecting block, and the other end of the mounting substrate is in contact with the inner wall of the arc extinguishing chamber. A plurality of air holes are provided on the surface of the mounting substrate. The mounting substrate divides the arc extinguishing chamber into two upper and lower chambers, which are connected through the air holes. A second exhaust channel is provided inside the plastic shell, and the second exhaust channel connects the chamber on the upper side of the mounting substrate with the outside of the plastic shell. Heat is generated in the arc extinguishing chamber and discharged to the outside through the second exhaust channel.

[0012] The present invention has the following beneficial effects:

[0013] 1. The separate arc extinguishing chamber of the circuit breaker is provided with a separate arc extinguishing grid assembly in the arc extinguishing chamber. The arc extinguishing grids in the separate arc extinguishing grid assembly are arranged separately. When the moving contact and the static contact are disconnected to generate an arc, the spacing between the arc extinguishing grids increases rapidly from a small distance. While cutting a long arc into a short arc, the short arc is stretched and the thick arc is divided into a thin arc. The air resistance in the gap between adjacent arc extinguishing grids increases with the increase of the gap spacing, so that the arc voltage on each gap is reduced, thereby prompting the arc to be extinguished quickly. This design solves the problem of increasing the number of arc extinguishing grids required to cut a short arc.

[0014] 2. The separate arc-extinguishing grid assembly proposed in the present invention has good synchronization when releasing the force on the arc-extinguishing grid by flipping the swing partition, and the spacing between the arc-extinguishing grids is rapidly increased. Compared with the narrow gap, the air resistance is reduced, and the arc in the air is more likely to enter the gap between the arc-extinguishing grids under the action of the hot air flow. In this process, since the gap between the arc-extinguishing grids increases from small to large, negative pressure is generated, which accelerates the entry of the arc and the hot air flow and shortens the arc burning time. In addition, the magnetic field generated by the second magnetic block and the fourth magnetic block pulls the arc into the gap between the arc-extinguishing grids to prevent the arc burning time from being long and the arc overflowing from the grid to burn other objects.

[0015] 3. By arranging a swinging partition in the arc extinguishing chamber, and the moving contact is fixedly connected to the swinging partition, when the moving contact is disconnected, the swinging partition is driven to flip synchronously, and the swinging partition compresses the air in the air pressure chamber. The compressed air is injected into the arc extinguishing chamber through the first exhaust channel, further accelerating the arc and hot air flow into the gap of the arc extinguishing grid, and the hot air in the arc extinguishing chamber is discharged from the second exhaust channel to achieve arc blowing and cooling. When the moving contact is closed, the swinging partition is driven to flip synchronously, and a negative pressure is formed in the air pressure chamber, and the air in the arc extinguishing chamber is sucked into the air pressure chamber. At the same time, the outside air enters the arc extinguishing chamber from the second exhaust channel, which has the effect of cooling the arc extinguishing chamber. This design can prevent the problem of heat accumulation in the arc extinguishing chamber caused by frequent opening and closing, and is safer to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a three-dimensional schematic diagram of the internal structure of the plastic shell proposed by the present invention;

[0017] Figure 2 A schematic diagram of the three-dimensional structure of the separated arc-extinguishing grid assembly proposed by the present invention (I);

[0018] Figure 3 A schematic diagram of the three-dimensional structure of the separated arc-extinguishing grid assembly proposed by the present invention (II);

[0019] Figure 4 for Figure 1 The enlarged structural diagram at H in the middle;

[0020] Figure 5 This is a schematic diagram of the front section structure of the plastic housing (a schematic diagram of the arc-extinguishing grid force);

[0021] Figure 6 It is a schematic diagram of the front section structure of the plastic shell (schematic diagram of the swing partition action);

[0022] Figure 7 Schematic diagram of the arc extinguishing grid (tilted-vertical) flipping.

[0023] In the figure: 1 plastic housing, 2 static contact, 3 moving contact, 4 swing partition, 5 arc extinguishing grid, 6 mounting base plate, 7 transmission plate, 8 connecting shaft, 9 first magnetic block, 10 second magnetic block, 11 third magnetic block, 12 fourth magnetic block, 13 connecting block, 14 air pressure chamber, 15 arc extinguishing chamber, 16 arc striking window, 17 air hole, 18 first exhaust channel, 19 second exhaust channel, 20 arc column. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] Reference Figure 1-7 A separate arc extinguishing chamber of a circuit breaker, the arc extinguishing chamber is arranged inside a plastic shell 1, a static contact 2, a moving contact 3 and a trigger transmission mechanism for triggering the moving contact 3 are arranged inside the plastic shell 1, a swing partition 4 is rotatably installed inside the arc extinguishing chamber, the moving contact 3 is fixedly connected to the swing partition 4, the static contact 2 is fixedly installed in the plastic shell 1, and the trigger transmission mechanism of the circuit breaker belongs to the conventional setting of the prior art and will not be described here.

[0027] A separate arc extinguishing grid assembly is installed in the arc extinguishing chamber, and the separate arc extinguishing grid assembly is arranged in the area between the stationary contact 2 and the swing partition 4.

[0028] Specifically, a connecting block 13 is fixedly installed inside the arc extinguishing chamber, the upper side of the swinging partition 4 is rotatably connected to the connecting block 13, the lower side of the swinging partition 4 is in sliding contact with the inner wall of the arc extinguishing chamber, and the swinging partition 4 divides the inner cavity of the arc extinguishing chamber into an air pressure chamber 14 and an arc extinguishing chamber 15. A first exhaust channel 18 is opened on the surface of the swinging partition 4, and the air pressure chamber 14 is connected to the arc extinguishing chamber 15 through the first exhaust channel 18.

[0029] An arc striking window 16 is provided on the inner wall of the arc extinguishing chamber, the static contact 2 is fixed on the outside of the arc striking window 16 , the static contact 2 is connected with the arc extinguishing chamber 15 through the arc striking window 16 , and the separate arc extinguishing grid assembly is arranged in the arc extinguishing chamber 15 .

[0030] In this embodiment, Figure 3 As shown, the separated arc-extinguishing grid assembly includes a plurality of arc-extinguishing grids 5, a mounting base plate 6 and a transmission plate 7. The top ends of the plurality of arc-extinguishing grids 5 are rotatably connected to the mounting base plate 6, and the plurality of arc-extinguishing grids 5 are arranged in parallel. A connecting shaft 8 is fixedly installed on both sides of each arc-extinguishing grid 5. Each arc-extinguishing grid 5 is rotatably connected to the transmission plate 7 through the connecting shaft 8, so that the plurality of parallel arc-extinguishing grids 5 are turned synchronously. When the moving contact 3 contacts the stationary contact 2, the swing partition plate 4 provides a force for the arc-extinguishing grid 5, so that the gap between the arc-extinguishing grids 5 is reduced. When the moving contact 3 is separated from the stationary contact 2, the gap between the arc-extinguishing grids 5 gradually increases.

[0031] One end of the mounting substrate 6 contacts the connecting block 13, and the other end of the mounting substrate 6 contacts the inner wall of the arc extinguishing chamber 15. A plurality of air holes 17 are provided on the surface of the mounting substrate 6. The mounting substrate 6 divides the arc extinguishing chamber 15 into two upper and lower chambers, which are connected through the air holes 17. A second exhaust channel 19 is provided inside the plastic shell 1, and the second exhaust channel 19 connects the chamber on the upper side of the mounting substrate 6 with the outside of the plastic shell 1.

[0032] A first magnetic block 9 is fixedly mounted on the surface of the swing partition 4, and a second magnetic block 10 is fixedly mounted on the surface of the arc extinguishing grid 5 close to the swing partition 4. The force provided by the swing partition 4 to the arc extinguishing grid 5 is the magnetic repulsion force of the first magnetic block 9 and the second magnetic block 10. Figure 5 As shown in F1.

[0033] The inner wall of the arc extinguishing chamber is fixedly mounted with a third magnetic block 11, and the surface of the arc extinguishing grid 5 away from the swing partition 4 is fixedly mounted with a fourth magnetic block 12. The third magnetic block 11 and the fourth magnetic block 12 repel each other. Figure 5 As shown in F2,

[0034] Working principle: When the moving contact 3 is in contact with the stationary contact 2, F1 = F2, and the arc extinguishing grids 5 maintain an inclined equilibrium state. When the moving contact 3 is separated from the stationary contact 2, Figure 6 As shown by the arrow A in the middle, during the flipping process of the swing partition 4, F1 < F2, each arc extinguishing grid 5 flips in the direction of the arrow B, and finally F1 = F2, and the multiple arc extinguishing grids 5 maintain a vertical equilibrium state, refer to Figure 7 The shortest distance between two arc-extinguishing grids 5 in an inclined state is L1, and the shortest distance between two arc-extinguishing grids 5 in a vertical state is L2. Since the hypotenuse of the right triangle is the longest, L2 is greater than L1, that is, when the moving contact 3 is separated from the static contact 2, the gaps between the multiple arc-extinguishing grids 5 gradually increase, and the air conductivity in the gaps between adjacent arc-extinguishing grids 5 decreases as the gap spacing increases.

[0035] During the arc extinguishing process, Figure 5 As shown, the moving contact 3 and the stationary contact 2 are separated, and an arc column 20 is generated between the two. The arc column 20 generates high temperature and high light, which heats up the air inside. The arc column 20 and the high-temperature air enter the gap between the arc-extinguishing grids 5 upward. The arc-extinguishing grids 5 divide the arc into several short arcs, and use the cathode effect of the AC arc and the voltage drop of the DC arc to extinguish the arc. The high-temperature air expands and is discharged to the outside from the air hole 17 and the second exhaust channel 19, as shown in FIG. Figure 6 As shown by arrow C in the middle.

[0036] The separate arc extinguishing chamber of the circuit breaker is provided with a separate arc extinguishing grid assembly in the arc extinguishing chamber. The arc extinguishing grids 5 in the separate arc extinguishing grid assembly are arranged separately. When the moving contact 3 and the stationary contact 2 are disconnected to generate an arc, the spacing between the arc extinguishing grids 5 increases rapidly from a small distance, and the long arc is cut into a short arc. At the same time, the short arc is stretched, and the thick arc is divided into thin arcs. The air conductivity in the gaps between adjacent arc extinguishing grids 5 decreases as the gap spacing increases, so that the arc voltage on each gap is reduced, thereby prompting the arc to be extinguished quickly. This design solves the problem of increasing the number of arc extinguishing grids 5 required to cut a short arc.

[0037] As is known to all, electric arc is a form of gas discharge. Since electric arc is mainly generated when the contacts disconnect the circuit, the high temperature will burn the contacts and insulation. In severe cases, it may even cause phase short circuit and electrical explosion, thus causing fire and endangering the safety of personnel and equipment. The arc extinguishing grid 5 is used to divide the arc into several short arcs. Since the arc is affected by air resistance when entering the gap of the arc extinguishing grid 5, the arc extinguishing is delayed. The longer the arc burning time, the greater the destructive force generated, and the greater the probability of the arc reigniting.

[0038] The circuit breaker proposed in the present invention has good synchronization when releasing the force on the arc extinguishing grid 5 by flipping the swing partition 4, and the spacing between the arc extinguishing grids 5 is rapidly increased. Compared with the narrow gap, the air resistance is reduced, and the arc in the air is more likely to enter the gap of each arc extinguishing grid 5 under the action of the hot air flow. In this process, since the gap of each arc extinguishing grid 5 is increased from small to large, negative pressure is generated, which accelerates the entry of the arc and the hot air flow and shortens the arc burning time. In addition, the magnetic field generated by the second magnetic block 10 and the fourth magnetic block 12 pulls the arc into the gap of the arc extinguishing grid 5 to prevent the arc burning time from being long and the arc overflowing outside the grid to burn other objects.

[0039] By arranging a swing partition 4 in the arc extinguishing chamber, and the moving contact 3 is fixedly connected to the swing partition 4, when the moving contact 3 and the static contact 2 are disconnected, the swing partition 4 is driven to turn synchronously, and the swing partition 4 compresses the air in the air pressure chamber 14, and the compressed air is injected into the arc extinguishing chamber 15 through the first exhaust channel 18. Figure 6 As shown by the middle arrow D, the arc and hot air flow are further accelerated to enter the gap of the arc extinguishing grid 5, and the hot air of the arc extinguishing chamber 15 is discharged from the second exhaust channel 19 to achieve arc blowing and cooling. When the moving contact 3 and the static contact 2 are closed, the swing partition 4 is driven to flip synchronously, and a negative pressure is formed in the air pressure chamber 14, so that the air in the arc extinguishing chamber 15 is sucked into the air pressure chamber 14. At the same time, the outside air enters the arc extinguishing chamber 15 from the second exhaust channel 19, which has the effect of cooling the arc extinguishing chamber 15. This design can prevent the problem of heat accumulation in the arc extinguishing chamber 15 due to frequent opening and closing, and is safer to use.

[0040] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A separate arc extinguishing chamber of a circuit breaker, the arc extinguishing chamber being arranged inside a plastic housing (1), a stationary contact (2) and a moving contact (3) being arranged inside the plastic housing (1), characterized in that: A swinging partition (4) is rotatably mounted inside the arc extinguishing chamber, the moving contact (3) is fixedly connected to the swinging partition (4), the stationary contact (2) is fixedly mounted in the plastic housing (1), a separate arc extinguishing grid assembly is mounted in the arc extinguishing chamber, and the separate arc extinguishing grid assembly is arranged in the area between the stationary contact (2) and the swinging partition (4); The separated arc extinguishing grid assembly comprises a plurality of arc extinguishing grids (5); when the moving contact (3) contacts the stationary contact (2), the swing partition (4) provides a force for the arc extinguishing grids (5) so that the gaps between the arc extinguishing grids (5) are reduced; when the moving contact (3) separates from the stationary contact (2), the gaps between the arc extinguishing grids (5) gradually increase; The separate arc extinguishing grid assembly comprises a mounting base (6) and a transmission plate (7), the top ends of a plurality of arc extinguishing grids (5) are rotatably connected to the mounting base (6), the plurality of arc extinguishing grids (5) are arranged in parallel, a connecting shaft (8) is fixedly mounted on both sides of each arc extinguishing grid (5), and each arc extinguishing grid (5) is rotatably connected to the transmission plate (7) via the connecting shaft (8).

2. The separate arc extinguishing chamber of a circuit breaker according to claim 1, characterized in that: A first magnetic block (9) is fixedly mounted on the surface of the swing baffle (4), and a second magnetic block (10) is fixedly mounted on the surface of the arc extinguishing grid (5) close to the swing baffle (4), and the acting force is the magnetic repulsion of the first magnetic block (9) and the second magnetic block (10).

3. The separate arc extinguishing chamber of a circuit breaker according to claim 2, characterized in that: A third magnetic block (11) is fixedly mounted on the inner wall of the arc extinguishing chamber, and a fourth magnetic block (12) is fixedly mounted on the surface of the arc extinguishing grid (5) away from the swing partition (4); the third magnetic block (11) and the fourth magnetic block (12) repel each other.

4. The separate arc extinguishing chamber of a circuit breaker according to claim 3, characterized in that: A connecting block (13) is fixedly installed inside the arc extinguishing chamber, the upper side of the swinging partition (4) is rotatably connected to the connecting block (13), the lower side of the swinging partition (4) is in sliding contact with the inner wall of the arc extinguishing chamber, and the swinging partition (4) divides the inner cavity of the arc extinguishing chamber into a gas pressure cavity (14) and an arc extinguishing cavity (15).

5. The separate arc extinguishing chamber of a circuit breaker according to claim 4, characterized in that: An arc striking window (16) is provided on the inner wall of the arc extinguishing chamber, a stationary contact (2) is fixed on the outside of the arc striking window (16), the stationary contact (2) is connected to the arc extinguishing chamber (15) through the arc striking window (16), and a separate arc extinguishing grid assembly is arranged in the arc extinguishing chamber (15).

6. The separate arc extinguishing chamber of a circuit breaker according to claim 5, characterized in that: A first exhaust passage (18) is provided on the surface of the swing partition plate (4), and the air pressure chamber (14) is connected to the arc extinguishing chamber (15) through the first exhaust passage (18).

7. The separate arc extinguishing chamber of a circuit breaker according to claim 6, characterized in that: One end of the mounting substrate (6) contacts the connection block (13), and the other end of the mounting substrate (6) contacts the inner wall of the arc extinguishing chamber (15). A plurality of air holes (17) are provided on the surface of the mounting substrate (6). The mounting substrate (6) divides the arc extinguishing chamber (15) into two upper and lower chambers, and the upper and lower chambers are connected via the air holes (17).

8. The separate arc extinguishing chamber of a circuit breaker according to claim 7, characterized in that: A second exhaust passage (19) is provided inside the plastic housing (1), and the second exhaust passage (19) connects the cavity on the upper side of the mounting substrate (6) with the outside of the plastic housing (1).

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