Circuit breaker

Abstract

A circuit breaker comprises a shell, an operating mechanism, a contact mechanism and an arc extinguishing system, the contact mechanism comprises a moving contact and a static contact which are opposite to each other in a spaced mode in the first direction, the arc extinguishing system comprises an arc extinguishing chamber, an arcing space and a magnetic conductive plate, the arc extinguishing chamber, the arcing space and the operating mechanism are arranged in the second direction, and the arcing space is communicated with the arc extinguishing chamber. The inlet of the arcing space faces the operating mechanism, the two magnetic conductive plates are opposite in a spaced mode in the third direction, at least one magnetic conductive plate is provided with an extending part extending in the third direction, in the first direction, the length of the inlet is smaller than that of the arcing space, and the extending part and the inlet are arranged side by side to connect the two magnetic conductive plates together; and the moving contact extends into the arcing space from the inlet and is matched with the static contact. According to the utility model, the moving contact and the static contact are matched in the arc extinguish chamber, more arc extinguish grid sheets can be configured, and the extension part of the magnetic conductive plate is connected at the inlet, so that the internal space can be saved, the magnetic field at the inlet can be enhanced conveniently, and the arc can enter the arc extinguish chamber quickly.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of low-voltage electrical apparatus, and particularly relates to a circuit breaker. BACKGROUND

[0002] The circuit breaker is a switching device capable of making, carrying and breaking the current under normal circuit conditions, and making, carrying and breaking the current under abnormal circuit conditions within a specified time. In the circuit breaker, the contact mechanism generates an electric arc when closing and opening, and the arc is extinguished by the arc extinguishing system. In the existing product, the arc extinguishing system is limited by the internal space, so that the assembly position of the arc extinguishing chamber, the number of grid plates, the speed of the arc entering the arc extinguishing chamber and the exhaust way of the tail gas are all affected, thereby affecting the arc extinguishing capacity of the arc extinguishing system and causing the breaking capacity of the circuit breaker to be unable to be further improved. SUMMARY

[0003] The utility model discloses a circuit breaker which overcomes at least one defect of the prior art.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0005] The utility model provides a circuit breaker, including the shell, be provided with operating mechanism, contact mechanism and arc extinguishing system in the shell, the contact mechanism includes the dynamic contact and static contact who are opposite in the first direction interval, the arc extinguishing system includes arc extinguishing chamber and burning space, the arc extinguishing chamber, burning space and operating mechanism are sequentially arranged along the second direction, the burning space is connected with the arc extinguishing chamber, and the entrance of the burning space faces the operating mechanism, the arc extinguishing system still includes two magnetic conductive plates who are opposite in the third direction interval, the first direction, the second direction and the third direction are perpendicular to each other, at least one magnetic conductive plate is equipped with the extension along the third direction extension, in the first direction, the length of the entrance is less than the length of the burning space, the extension is set up for connecting two magnetic conductive plates together with the entrance side by side, the dynamic contact extends from the entrance to the static contact in the burning space and is matched with the static contact arranged in the burning space.

[0006] Preferably, one of the magnetic conductive plates is provided with a first extension, and the other magnetic conductive plate is provided with a second extension, in the second direction, the second extension is located between the first extension and the static contact, and the second extension is adjacent to the side of the static contact facing away from the dynamic contact.

[0007] Preferably, the entrance cover is provided with an arc separation plate, the arc separation plate is provided with a central groove, and the dynamic contact extends to the burning space through the central groove.

[0008] Preferably, the arc extinguishing chamber is provided with a grid group, the grid group comprises a plurality of arc extinguishing grids arranged in a first direction, and in a second direction, the width of each magnetic conductive plate is less than or equal to the sum of the width of the arc space and the width of the arc extinguishing chamber.

[0009] Preferably, in the second direction, the width of the magnetic conductive plate is equal to the width of the arc space, so that each magnetic conductive plate corresponds to the arc space outside the grid group and the inlet.

[0010] Preferably, in the second direction, the plurality of arc extinguishing grids are arranged to form a fan-shaped grid group.

[0011] Preferably, the arc extinguishing chamber is provided with an exhaust end away from the inlet, and an arc running channel is connected between the exhaust end and an exhaust hole opened on the shell, and the arc running channel is arranged between the exhaust end and the exhaust hole in the first direction.

[0012] Preferably, the arc running channel is provided with a partition in the first direction, and the arc running channel is divided into two parts by the partition, and each part of the arc running channel is communicated with one of the exhaust holes.

[0013] Preferably, the inner diameter of the arc running channel near the exhaust hole is greater than the inner diameter near the partition.

[0014] Preferably, the shell further comprises an operating mechanism and a short-circuit protection mechanism arranged side by side in the first direction, and in the second direction, the operating mechanism is opposite to the inlet, and the short-circuit protection mechanism is opposite to the partial extension.

[0015] Preferably, the arc extinguishing system further comprises a dynamic arc striking angle and a static arc striking angle, the dynamic arc striking angle and the static arc striking angle are arranged at the inlet and are opposite to each other in the first direction, one end of the static arc striking angle near the inlet is connected with a static contact, the middle part of the static arc striking angle is bent and extends along the inside of the arc space in the first direction, and in the second direction, the middle part of the static arc striking angle is distributed on the inside and the outside of the arc space, and the other end of the static arc striking angle extends to one end of the grid group in the arc extinguishing chamber in the second direction.

[0016] The circuit breaker of the utility model, the dynamic contact and the static contact cooperate in the arc space, and the length of the inlet is less than the length of the arc space, so that the arc extinguishing chamber has a larger internal space in the limited space, which is beneficial to arranging more arc extinguishing grids, and the extension of the magnetic conductive plate is connected at the inlet, which can save internal space and facilitate the enhancement of the magnetic field at the inlet, so as to promote the arc striking and arc extinguishing capacity of the arc extinguishing system.

[0017] In addition, the two magnetic conductive plates are connected through two extensions, the second extension is adjacent to the static contact for enhancing the magnetic field at the static contact, facilitating the arc being introduced from the static contact into the arc-extinguishing chamber, in particular, the first extension corresponds to the short-circuit protection mechanism, and is distributed corresponding to the static arc striking angle, fully utilizing the internal space and improving the arc striking efficiency.

[0018] In addition, the inlet cover is provided with an arc separation plate, which can block the arc from overflowing from the inlet, so that the arc is limited in the arc-extinguishing chamber for cutting, thereby improving the breaking capacity of the circuit breaker.

[0019] In addition, the magnetic conductive plate is located between the grid group and the inlet, has small volume, and has the advantages of saving space and reducing cost.

[0020] In addition, a separation part is arranged in the arc running channel, the arc running channel is divided into two parts, and the tail gas is discharged from the two exhaust holes, facilitating the rapid discharge of the tail gas. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the structure schematic diagram of the circuit breaker in the closing of the utility model;

[0022] Figure 2 is the structure schematic diagram of the circuit breaker in the opening of the utility model;

[0023] Figure 3 is the cooperation schematic diagram of the first extension, the second extension and the static contact in the utility model;

[0024] Figure 4 is the structure schematic diagram of the magnetic conductive plate in the utility model Figure 1 ;

[0025] Figure 5 is the structure schematic diagram of the magnetic conductive plate in the utility model Figure 2 ;

[0026] Figure 6 is the structure schematic diagram of the arc separation plate in the utility model;

[0027] REFERENCE SIGNS:

[0028] 1-outer shell, 10-exhaust hole, 11-separation part, 2-operation mechanism, 21-lever, 22-jump buckle, 23-lock buckle, 31-moving contact, 32-static contact, 40-arc-extinguishing chamber, 41-arc space, 42-inlet, 431-moving arc striking angle, 432-static arc striking angle, 44-arc running channel, 45-magnetic conductive plate, 451-first extension, 452-second extension, 453-strip-shaped convex edge, 46-gas generating part, 47-arc separation plate, 471-central groove, 474-avoidance groove, 5-overload protection mechanism, 6-short-circuit protection mechanism, 8-handle mechanism, 9-wiring terminal. DETAILED DESCRIPTION

[0029] The specific embodiments of the circuit breaker of this utility model are further described below with reference to the accompanying drawings. The circuit breaker of this utility model is not limited to the descriptions in the following embodiments.

[0030] like Figure 1 , 2 As shown, the circuit breaker includes a housing 1. The opposite ends of the housing 1 serve as terminals and are equipped with terminals 9. The terminals 9 are typically arranged in pairs. The terminals 9 mate with the wiring ports of the housing 1 for external wiring. An operating mechanism 2, a contact mechanism, and an arc-extinguishing system are rotatably mounted inside the housing 1. The operating mechanism 2 is linked to a handle mechanism 8. The operating element of the handle mechanism 8 extends from a handle hole in the housing 1 to the outside of the housing 1 for manual operation of the circuit breaker's opening and closing. The contact mechanism is electrically connected between a pair of terminals 9 and is used to control the connection and disconnection of the connected lines. The contact mechanism includes a stationary contact 32 and a moving contact 31 that cooperate with each other. The stationary contact 32 is fixedly installed inside the housing 1, and the moving contact 31 is connected to the operating mechanism 2 and spaced apart from the stationary contact 32. The operating mechanism 2 drives the moving contact 31 to move closer to or away from the stationary contact 32. The arc-extinguishing system includes an arc-extinguishing chamber 40 and an arc-ignition space 41. Figures 1-3 (The area surrounded by the dotted line) The arc-ignition space 41 is connected to the interior of the arc-extinguishing chamber 40. The inlet 42 of the arc-ignition space 41 is connected to the contact mechanism to introduce the electric arc generated by the contact mechanism into the arc-extinguishing chamber 40. The end of the arc-extinguishing chamber 40 away from the inlet 42 serves as the exhaust end. After the electric arc is cut off and extinguished in the arc-extinguishing chamber 40, the exhaust gas generated is discharged from the exhaust end of the arc-extinguishing chamber 40 and the exhaust port opened on the outer shell 1 in sequence. The arc-extinguishing system also includes a pair of spaced magnetic plates 45, which enhance the electric arc in the arc-ignition space 41 and the arc-extinguishing chamber 40 to improve the arc-ignition and arc-extinguishing effects.

[0031] For ease of description, the length, height, and width of the circuit breaker are respectively referred to as the first direction, the second direction, and the third direction. The first direction, the second direction, and the third direction are perpendicular to each other. That is, the direction of the connection between the two terminals is taken as the first direction. Each pair of terminals 9 is spaced apart and opposite to each other in the first direction. The moving contact 31 and the stationary contact 32 of the contact mechanism are spaced apart and opposite to each other in the first direction. The operating mechanism 2, the arcing space 41, and the arc extinguishing chamber 40 are arranged sequentially along the second direction. A pair of magnetic plates 45 are spaced apart in the third direction. Figures 1-2 In the diagram, the first direction is the left-right direction, which is the direction of the X-axis; the second direction is the up-down direction, which is the direction of the Y-axis; and the third direction is the direction perpendicular to the paper.

[0032] The improvement of the present application is that at least one magnetic conducting plate 45 is provided with an extension part extending along the third direction, the length of the inlet 42 is less than the length of the arc burning space 41 in the first direction, the extension part is arranged side by side with the inlet 42 for connecting the two magnetic conducting plates 45 together, and the movable contact 31 extends from the inlet 42 into the arc burning space 41 to cooperate with the static contact 32 arranged in the arc burning space 41.

[0033] In this way, the movable contact 31 cooperates with the static contact 32 in the arc burning space 41, and the length of the inlet 42 is less than the length of the arc burning space 41, so that the arc chamber 40 has a larger internal space in a limited space, which is beneficial to arranging more arc extinguishing vanes, and the extension part of the magnetic conducting plate 45 is connected at the inlet 42, which can not only save internal space, but also facilitate the enhancement of the magnetic field at the inlet 42 to promote the arc to quickly enter the arc chamber 40, thereby improving the arc striking and extinguishing capacity of the arc extinguishing system.

[0034] Specifically, as shown in Figure 4 , 5 , one of the magnetic conducting plates 45 is provided with a first extension part 451, and the other magnetic conducting plate 45 is provided with a second extension part 452, and in the second direction, the second extension part 452 is located between the first extension part 451 and the static contact 32, and the second extension part 452 is adjacent to the side of the static contact 32 facing away from the movable contact 31, and the first extension part 451 and the second extension part 452 make the two magnetic conducting plates 45 have two connection positions, and the second extension part 452 is adjacent to the static contact 32 for enhancing the magnetic field at the static contact 32, which is beneficial to the arc being introduced into the arc chamber 40 from the static contact 32.

[0035] As shown in Figure 1 , 2 , a vane group is arranged in the arc chamber 40, the vane group includes a plurality of arc extinguishing vanes arranged at intervals in the first direction, preferably, the plurality of arc extinguishing vanes are arranged to form a fan-shaped vane group, the interval between the adjacent two arc extinguishing vanes at the end close to the inlet 42 is less than the interval between the adjacent two arc extinguishing vanes at the end close to the exhaust end, and in the second direction, the width of each magnetic conducting plate 45 is less than or equal to the sum of the width of the arc chamber 40 and the width of the arc burning space 41, and preferably, the width of each magnetic conducting plate 45 is equal to the width of the arc burning space 41, so that each magnetic conducting plate 45 is located between the vane group and the inlet 42, in this way, the magnetic conducting plate 45 only covers the area outside the arc burning space 41 between the inlet 42 and the vane group, which has a smaller volume and has the advantages of saving space and reducing cost.

[0036] Preferably, as shown in Figures 1-2As shown in Figure 6, the inlet 42 is covered with an arc-blocking plate 47. The center of the arc-blocking plate 47 is provided with a central groove 471, which is connected to the arc-extinguishing space 41. The moving contact 31 extends through the central groove 471 into the arc-extinguishing space 41, which can prevent the arc from overflowing from the inlet 42 and prevent the arc from flowing in the circuit breaker. This confines the arc to the arc-extinguishing chamber 40 for cutting, thereby improving the breaking capacity of the circuit breaker.

[0037] In addition, such as Figure 1 , 2 As shown, an arc-running channel 44 is connected between the exhaust end and the exhaust port 10 of the outer casing 1. The arc-running channel 44 is arranged between the exhaust end and the exhaust port 10 along the first direction. Preferably, a partition 11 is provided in the exhaust channel. The partition 11 is preferably formed by the inner sidewall of the outer casing 1, so that the partition 11 divides the arc-running channel 44 into two parts in the first direction. Each part of the arc-running channel 44 is connected to one exhaust port 10, so that the exhaust gas discharged from the exhaust end can be discharged from the two exhaust ports 10 respectively, which is conducive to the rapid discharge of exhaust gas.

[0038] Combination Figures 1-6 An embodiment of a circuit breaker is provided.

[0039] like Figure 1 , 2 As shown, the circuit breaker includes a housing 1. Inside the housing 1 are a pair of terminals 9 spaced apart and opposite each other in a first direction. Between the terminals 9 are a handle mechanism 8, an operating mechanism 2, and an arc-extinguishing system. In a second direction, the handle mechanism 8, operating mechanism 2, and arc-extinguishing system are arranged sequentially. The handle mechanism 8 and operating mechanism 2 are rotatably assembled. The operating element of the handle mechanism 8 extends from the handle hole of the housing 1 to the outside of the housing 1. The contact mechanism includes a moving contact 31 and a stationary contact 32 spaced apart and opposite each other in the first direction. The moving contact 31 is connected to the operating mechanism 2. The arc-extinguishing system includes an arc-extinguishing chamber 40 and an arc-ignition space 41. In the second direction, the operating mechanism 2, arc-ignition space 41, and arc-extinguishing chamber 40 are arranged sequentially. The arc-ignition space 41 communicates with the interior of the arc-extinguishing chamber 40. The inlet 42 faces the operating mechanism 2. The end of the arc-extinguishing chamber 40 away from the inlet 42 serves as the exhaust end. The arc-extinguishing chamber 40 is provided with a grid plate assembly for cutting the electric arc. The moving contact 31 extends from the inlet 42 into the arc-burning space 41 along the second direction and cooperates with the stationary contact 32 provided in the arc-burning space 41. The inlet 42 is provided with a moving arc-starting angle 431 and a stationary arc-starting angle 432 spaced apart in the first direction. The end of the stationary arc-starting angle 432 near the inlet 42 is connected to the stationary contact 32. The middle part of the stationary arc-starting angle 432 is bent and extends along the inner side of the arc-burning space 41 in the first direction, so that the other end of the stationary arc-starting angle 432 extends along the second direction to one end of the grid plate assembly of the arc-extinguishing chamber 40. The moving arc-starting angle 431 is correspondingly provided at the other end of the grid plate assembly and corresponds to the moving contact 31 in the open position.

[0040] In the embodiment, the handle mechanism 8, the operating mechanism 2 and the contact mechanism adopt the prior art, that is, the operating mechanism 2 comprises a rotatingly assembled lever 21, the lever 21 is rotatingly assembled with a snap-fitted trip 22 and a lock 23, the handle mechanism 8 is connected with the lever 21 through a linkage rod, the moving contact 31 is coaxially assembled with the lever 21, and a contact spring is arranged between the moving contact 31 and the lever 21, when the moving contact 31 and the lever 21 move relatively, the contact spring is energized to drive the moving contact 31 to quickly close.

[0041] As shown in Figure 1 , 2 In the embodiment, the housing 1 further comprises a protection mechanism cooperating with the operating mechanism 2, the protection mechanism comprises a short-circuit protection mechanism 6 and an overload protection mechanism 5, wherein the short-circuit protection mechanism 6 is arranged side by side with the operating mechanism 2 in the first direction, in the second direction, the short-circuit protection mechanism 6 is located between the handle mechanism 8 and the arc extinguishing system, the short-circuit protection mechanism 6 corresponds to the partial extension part, the short-circuit protection mechanism 6 can adopt an electromagnetic release, after a short-circuit fault occurs, the operating mechanism 2 is tripped by the short-circuit protection mechanism 6; in the first direction, the overload protection mechanism 5 is arranged between the arc extinguishing system and one terminal 9, and the overload protection mechanism 5 is distributed on the opposite side of the operating mechanism 2 from the short-circuit protection mechanism 6, the overload protection mechanism 5 is made of bimetallic material.

[0042] In the embodiment, as shown in Figure 1 , 2 and 6, the cover at the inlet 42 is provided with an arc separation plate 47, the middle part of the arc separation plate 47 is provided with a central groove 471, the central groove 471 communicates with the inside of the arc space 41, the moving contact 31 passes through the central groove 471 and cooperates with the static contact 32 in the arc space 41, the electric arc is limited in the arc space 41 and the arc extinguishing chamber 40, and the electric arc flying out of the arc extinguishing system does not interfere with other parts in the circuit breaker, Figure 6 In the embodiment, the arc separation plate 47 is a rectangular plate body, a strip-shaped central groove 471 is formed in the middle part of the arc separation plate 47, one end of the arc separation plate 47 is provided with an avoiding groove 474, the static contact 32 or the static arc striking horn 432 is correspondingly located in the avoiding groove 474, which facilitates the connection with the adjacent short-circuit protection mechanism 6, and the avoiding groove 474 communicates with the central groove 471.

[0043] In the embodiment, the arc extinguishing system further comprises two magnetic conductive plates 45, which are spaced apart and opposite in the third direction and arranged outside the arc space 41. At least one of the magnetic conductive plates 45 is provided with an extension extending in the third direction. In the first direction, the length of the arc space 41 is approximately equal to the length of the arc extinguishing chamber 40, and the length of the inlet 42 of the arc space 41 is less than the length of the arc extinguishing chamber 40. The extension is arranged side by side with the inlet 42 to connect the two magnetic conductive plates 45 together. The magnetic conductive plates 45 can correspondingly enhance the magnetic field in the arc space 41, thereby accelerating the introduction of the arc generated by the contact mechanism into the grid group in the arc extinguishing chamber 40.

[0044] As shown in Figures 1-5 , one of the magnetic conductive plates 45 is provided with a first extension 451, and the other magnetic conductive plate 45 is provided with a second extension 452. Thus, the two magnetic conductive plates 45 are connected together by the two extensions respectively. In the second direction, the second extension 452 is located between the first extension 451 and the static contact 32, Figure 4 , 5 , the length of the second extension 452 is much less than the length of the first extension 451. The first extension 451 is opposite to the short-circuit protection mechanism 6, and the first extension 451 and the static arc striking angle 432 correspond to the inner and outer sides of the arc space 41 respectively, so that the static arc striking angle 432 is located in the magnetic field range enhanced by the first extension 451. The second extension 452 is adjacent to the side of the static contact 32 facing away from the moving contact 31, and the magnetic field at the static contact 32 is enhanced by the second extension 452, thereby facilitating the introduction of the arc into the arc extinguishing chamber 40.

[0045] Further, in the second direction, the width of the magnetic conductive plate 45 is less than the sum of the widths of the arc extinguishing chamber 40 and the arc space 41. Preferably, the width of the magnetic conductive plate 45 is equal to the width of the arc space 41, so that each magnetic conductive plate 45 corresponds to the arc space 41 outside the grid group and the inlet 42. In the embodiment, the grid group in the arc extinguishing chamber 40 comprises a plurality of arc extinguishing grids arranged in the first direction, Figure 1 , 2 , the plurality of arc extinguishing grids are arranged to form a fan-shaped grid group, that is, the interval between adjacent two arc extinguishing grids is less at the end close to the inlet 42 than at the end close to the exhaust end, facilitating the cutting of the arc and the exhaust of the tail gas.

[0046] In combination Figure 4 , 5The specific structure of the magnetic conductive plate 45 is provided, the magnetic conductive plate 45 includes a strip-shaped plate body, and edges of opposite sides of the plate body are respectively a first edge and a second edge, wherein the first edge is linear, the first edge faces the operating mechanism 2, and the second edge is an outwardly convex arc shape and corresponds to one end of the grid group close to the arc space 41; a slanting gap is arranged in the middle of the first edge, a strip-shaped convex edge 453 is formed by extending the first edge adjacent to the gap in a direction parallel to the plate surface, one corner of the strip-shaped convex edge 453 protrudes from the first edge, an end of the strip-shaped convex edge 453 extends in a third direction to form a second extension part 452, and the first edge adjacent to the other side of the gap extends in the third direction to form a rectangular first extension part 451; in the embodiment, the first extension part 451 and the second extension part 452 are respectively arranged on the two magnetic conductive plates 45, when the two magnetic conductive plates 45 are arranged outside the arc chamber 40 in the third direction, the second extension part 452 is connected to the corresponding strip-shaped convex edge 453, and the first extension part 451 is connected to the first edge of the other magnetic conductive plate 45, so as to form two connecting parts; of course, the first extension part 451 and the second extension part 452 can be arranged on the same magnetic conductive plate 45 at the same time, or the first extension part 451 and the second extension part 452 are arranged on the two magnetic conductive plates 45 together.

[0047] In addition, two gas generating parts 46 are arranged in the third direction in the arc space 41, and the two gas generating parts 46 are located between the two magnetic conductive plates 45, preferably, the size of the gas generating part 46 matches the size of the magnetic conductive plate 45, that is, in the second direction, the gas generating part 46 is located in the arc space 41 between the inlet 42 and the grid group, of course, the width of the gas generating part 46 can be equal to the sum of the width of the arc chamber 40 and the width of the arc space 41.

[0048] As shown in Figure 1 , 2 , the arc extinguishing system further includes an arc running channel 44, the arc running channel 44 corresponds to the exhaust end of the arc chamber 40 in the first direction, in the embodiment, in the second direction, the operating mechanism 2, the arc chamber 40 and the arc running channel 44 are sequentially arranged in the shell 1, the shell 1 is provided with an exhaust hole 10, the shell 1 is provided with two exhaust holes 10 in the figure, each exhaust hole 10 corresponds to the shell 1 below each terminal 9, each exhaust hole 10 is communicated with one end of the arc running channel 44, preferably, a partition 11 is arranged in the middle of the arc running channel 44, the arc running channel 44 is divided into two parts by the partition 11, each part of the arc running channel 44 is communicated with one exhaust hole 10, so that the exhaust gas discharged from the exhaust end is divided into two parts and is discharged from the shell 1 respectively; in the embodiment, the exhaust end of the arc chamber 40 is fan-shaped, so that the inner diameter of the arc running channel 44 at the end close to the exhaust hole 10 is greater than the inner diameter close to the partition 11, which is beneficial to the exhaust of the exhaust gas.

[0049] It should be noted that in the description of the present application, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings or the orientation or positional relationship commonly used in use, and are only for the convenience of description, and do not indicate that the device or element referred to must have a particular orientation, so it cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used for differentiation in description, and cannot be understood as indicating relative importance.

[0050] The above is a further detailed description of the present application in combination with specific preferred embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered as falling within the scope of protection of the present application.

Claims

1. A circuit breaker comprising a housing (1), an operating mechanism (2), a contact mechanism and an arc extinguishing system arranged in the housing (1), the contact mechanism comprising a moving contact (31) and a stationary contact (32) spaced apart in a first direction, the arc extinguishing system comprising an arc chamber (40) and an arc burning space (41), the arc chamber (40), the arc burning space (41) and the operating mechanism (2) being arranged in a second direction in sequence, the arc burning space (41) being in communication with the arc chamber (40), and an entrance (42) of the arc burning space (41) facing the operating mechanism (2), the arc extinguishing system further comprising two magnetic conductive plates (45) spaced apart in a third direction, the first direction, the second direction and the third direction being perpendicular to each other, characterized in that: At least one magnetic conductive plate (45) is provided with an extension part extending along the third direction, in the first direction, the length of the inlet (42) is less than the length of the arc burning space (41), the extension part is arranged side by side with the inlet (42) for connecting the two magnetic conductive plates (45) together, and the movable contact (31) extends from the inlet (42) into the arc burning space (41) to cooperate with the static contact (32) arranged in the arc burning space (41).

2. The circuit breaker of claim 1, wherein: One of the magnetic conductive plates (45) is provided with a first extension part (451), and the other magnetic conductive plate (45) is provided with a second extension part (452), in the second direction, the second extension part (452) is located between the first extension part (451) and the static contact (32), and the second extension part (452) is adjacent to the side of the static contact (32) facing away from the movable contact (31).

3. The circuit breaker of claim 2, wherein: The inlet (42) is provided with an arc separation plate (47), and the arc separation plate (47) is provided with a central groove (471), and the movable contact (31) extends into the arc burning space (41) through the central groove (471).

4. The circuit breaker of claim 1, wherein: A grid group is arranged in the arc extinguishing chamber (40), and the grid group includes a plurality of arc extinguishing grids arranged at intervals in the first direction, and in the second direction, the width of each magnetic conductive plate (45) is less than or equal to the sum of the width of the arc burning space (41) and the width of the arc extinguishing chamber (40).

5. The circuit breaker of claim 4, wherein: In the second direction, the width of the magnetic conductive plate (45) is equal to the width of the arc burning space (41), so that each magnetic conductive plate (45) corresponds to the arc burning space (41) outside the grid group and the inlet (42).

6. The circuit breaker of claim 4, wherein: In the second direction, the plurality of arc extinguishing grids are arranged to form a fan-shaped grid group.

7. The circuit breaker of claim 1, wherein: The side of the arc extinguishing chamber (40) away from the inlet (42) is an exhaust end, and an arc running channel (44) is connected between the exhaust end and the exhaust hole (10) arranged on the shell (1), and the arc running channel (44) is arranged between the exhaust end and the exhaust hole (10) along the first direction.

8. The circuit breaker of claim 7, wherein: The arc running channel (44) is provided with a partition (11), and the partition (11) divides the arc running channel (44) into two parts in the first direction, and each part of the arc running channel (44) communicates with one of the exhaust holes (10).

9. The circuit breaker of claim 8, wherein: The inner diameter of the end of the arc running channel (44) close to the exhaust hole (10) is greater than the inner diameter close to the partition (11).

10. The circuit breaker of claim 1, wherein: The shell (1) further includes an operating mechanism (2) and a short circuit protection mechanism (6) arranged side by side in the first direction, and in the second direction, the operating mechanism (2) is opposite to the inlet (42), and the short circuit protection mechanism (6) is opposite to the partial extension part.

11. The circuit breaker of claim 1, wherein: The arc extinguishing system further comprises a moving arc guiding horn (431) and a static arc guiding horn (432), the moving arc guiding horn (431) and the static arc guiding horn (432) are arranged at the entrance (42) and spaced apart in the first direction, one end of the static arc guiding horn (432) near the entrance (42) is connected with the static contact (32), the middle part of the static arc guiding horn (432) is bent and extends along the inside of the arc space (41) in the first direction, in the second direction, the middle part of the static arc guiding horn (432) and the extending part are arranged on the inside and the outside of the arc space (41), the other end of the static arc guiding horn (432) extends to one end of the grid group in the arc extinguishing chamber (40) in the second direction.

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