Circuit breaker

Abstract

The embodiment of the utility model provides a circuit breaker, and the circuit breaker comprises a housing which is internally provided with an arc extinguish chamber; the static contact is arranged on the shell and comprises a static contact point; the moving contact assembly is arranged in the shell and comprises a moving contact support and a moving contact; the arc extinguishing device is located in the arc extinguishing chamber and comprises an arc extinguishing grid piece set and two flash barriers, the peripheral wall of the arc extinguishing grid piece set comprises a first side face and a second side face which are opposite to each other and a third side face and a fourth side face which are opposite to each other, the first side face faces the static contact, and the second side face faces the second side face. The two flash barriers are arranged on the third side face and the fourth side face respectively, a backflow channel is formed between the peripheral wall of the arc extinguishing device and the peripheral wall of the arc extinguishing chamber, and the outlet end of the backflow channel is located between the first side face of the arc extinguishing grid piece set and the static contact. The outlet end comprises an open area and a closed area, and the closed area is close to the static contact.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to the field of electrical equipment, and more particularly to a circuit breaker. BACKGROUND

[0002] A circuit breaker is a switching device capable of making, carrying and breaking currents under normal circuit conditions and of breaking currents under abnormal circuit conditions to provide overload and short-circuit protection. When breaking the current, the circuit breaker generates an arc between the static contact and the moving contact, which can be introduced into the arc-extinguishing chamber under the action of magnetic blowing force and can be divided by the arc-extinguishing grid in the arc-extinguishing chamber to be extinguished.

[0003] A conventional circuit breaker is provided with a plate containing a gas generating material (also referred to as a gas generating sheet) in the housing. The wall of the arc-extinguishing chamber is provided with an exhaust port communicating with the outside. When the static contact and the moving contact are separated, an arc is generated between the static contact and the moving contact, and the gas generating sheet generates a large amount of gas due to temperature rise, which blows the arc to the arc-extinguishing grid while flowing to the exhaust port. However, when the gas is ejected from the exhaust port, there may be an arc that is not extinguished by the arc-extinguishing grid also ejected from the exhaust port, forming a flying arc, which is prone to cause equipment damage and even safety accidents. SUMMARY

[0004] The purpose of the present disclosure is to provide a circuit breaker to at least partially solve the above problems.

[0005] The present disclosure provides a circuit breaker, comprising: a housing, internally provided with an arc-extinguishing chamber; a static contact head, provided on the housing and comprising a static contact located in the housing; a moving contact assembly, provided in the housing and comprising a moving contact support and a moving contact provided on the moving contact support, the moving contact being capable of moving with the moving contact support to abut or separate from the static contact; and an arc-extinguishing device located in the arc-extinguishing chamber and comprising an arc-extinguishing grid set and two arc separation plates, an outer peripheral wall of the arc-extinguishing grid set comprising a first side and a second side opposite to each other, and a third side and a fourth side opposite to each other and located between the first side and the second side, the first side facing the static contact, the two arc separation plates being respectively provided on the third side and the fourth side, and a backflow channel being formed between the outer peripheral wall of the arc-extinguishing device and the peripheral wall of the arc-extinguishing chamber, an outlet end of the backflow channel being located between the first side of the arc-extinguishing grid set and the static contact, and the outlet end comprising an open area and a closed area, the closed area being close to the static contact.

[0006] In some embodiments, the interior of the housing is further formed with a communication cavity communicating with the arc-extinguishing chamber, and two partition plates containing a gas generating material are provided in the communication cavity, the two partition plates being located on both sides of the rotating path of the moving contact.

[0007] In some embodiments, each of the arc separation plates comprises a first bent portion bent towards the first side of the arc extinguishing fin set, and each of the arc separation plates has an extension portion extending into the arc extinguishing chamber, and the extension portion and the corresponding first bent portion form an outlet end of the backflow channel.

[0008] In some embodiments, a first portion of the first bent portion close to the stationary contact is connected with the corresponding extension portion to form the closed area, and a second portion of the first bent portion adjacent to the first portion is connected with the corresponding extension portion to form the open area.

[0009] In some embodiments, the second portion of the first bent portion and the surface of the corresponding extension portion opposite to each other have arc-shaped structures respectively, so that the open area faces the first side of the arc extinguishing fin set.

[0010] In some embodiments, the first portion of the first bent portion is provided with a second bent portion, and the second bent portion is lapped on the corresponding extension portion.

[0011] In some embodiments, the extension portion is provided with a recess for receiving the second bent portion.

[0012] In some embodiments, the first end of the arc extinguishing fin set is close to the stationary contact, and the second end of the arc extinguishing fin set extends obliquely towards a direction away from the stationary contact.

[0013] In some embodiments, the second end of the arc extinguishing fin set is provided with an arc striking fin extending into the communication cavity and clamped between the two arc separation plates.

[0014] In some embodiments, the arc extinguishing fin set comprises a plurality of arc extinguishing fins stacked together, the plurality of arc extinguishing fins comprises a first arc extinguishing fin adjacent to the stationary contact and a plurality of second arc extinguishing fins stacked on the first arc extinguishing fin in sequence, and the middle portion of the first arc extinguishing fin has a protruding portion extending towards the stationary contact, and each of the second arc extinguishing fins is provided with an arc extinguishing groove.

[0015] According to the circuit breaker of the embodiment of the present disclosure, the large amount of gas generated at the moment when the moving contact and the stationary contact are separated is circulated through the arc extinguishing grids of the arc extinguishing grid set in the arc extinguishing chamber by means of the reflux channel, so that the arc can be repeatedly divided by the arc extinguishing grids until it is completely extinguished. During the arc extinguishing process, the gas does not have to be sprayed out of the arc extinguishing chamber, realizing zero flying arc. The area adjacent to the stationary contact at the outlet end of the reflux channel is closed, so that the refluxing gas can flow to the upstream side of the arc extinguishing grid set away from the stationary contact. The gas flowing out of the open area of the outlet end enters the arc extinguishing grids away from the stationary contact in the vicinity under the push of the high-pressure gas on the upstream side of the arc extinguishing grid set. In this way, the overall utilization rate of the arc extinguishing grid set is improved, thereby shortening the arc time and effectively improving the arc back.

[0016] It should be understood that the content described in this part is not intended to limit the key features or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other features, advantages, and aspects of embodiments of the present disclosure will become more apparent by describing in detail the following embodiments with reference to the attached drawings. In the drawings, the same or similar reference numerals refer to the same or similar elements, in which:

[0018] Figure 1 An internal structure schematic diagram of a circuit breaker according to an embodiment of the present disclosure is shown;

[0019] Figure 2 A sectional view of the circuit breaker according to an embodiment of the present disclosure taken along the section line A-A shown in Figure 1 is shown;

[0020] Figure 3 A partial enlarged schematic view of the sectional view shown in Figure 2 is shown;

[0021] Figure 4 A sectional view of the circuit breaker according to an embodiment of the present disclosure taken along the section line B-B shown in Figure 1 is shown; and

[0022] Figure 5 A partial enlarged schematic view of the sectional view shown in Figure 4 is shown. DETAILED DESCRIPTION

[0023] Preferred embodiments of the present disclosure will be described in greater detail below, with reference to the accompanying drawings. While preferred embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0024] The term "comprising" and variations thereof as used herein are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Unless otherwise specified, the term "or" as used herein is intended to mean "and / or". The term "based on" means "based, at least in part, on". The terms "one example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "a first", "a second", etc. can refer to different or the same objects.

[0025] As described above, the arc-extinguishing chamber of a conventional circuit breaker is provided with an exhaust port through which a large amount of high-pressure gas generated when the stationary contact and the movable contact separate can be ejected. The flow of the large amount of high-pressure gas to the exhaust port can guide the arc generated at the moment of separation of the stationary contact and the movable contact to move toward the arc-extinguishing chamber, so that the arc is divided by the arc-extinguishing vanes. The arc that fails to be extinguished by the arc-extinguishing vanes can cause a flashover as the gas is ejected from the exhaust port, which can cause equipment damage or even a safety accident.

[0026] To avoid the arc from being ejected from the arc-extinguishing chamber, a backflow channel is formed in the arc-extinguishing chamber in the related art, the backflow channel is formed between the outer peripheral wall of the arc-extinguishing vane group and the peripheral wall of the arc-extinguishing chamber, and the arc-extinguishing chamber is not configured with an exhaust port. The outlet end of the backflow channel corresponds to the upstream side of the arc-extinguishing vane group. In the stacking direction of the arc-extinguishing vane group, the open length of the outlet end substantially coincides with the length of the arc-extinguishing vane group. When the stationary contact and the movable contact separate, a large amount of gas is generated, which can flow from the upstream side of the arc-extinguishing vane group to the downstream side of the arc-extinguishing vane group in the arc-extinguishing chamber, then return to the upstream side of the arc-extinguishing vane group along the backflow channel, and then continue to flow through the arc-extinguishing vane group under the push of the high-pressure gas accumulated at the upstream side of the arc-extinguishing vane group. The arc is repeatedly divided by the arc-extinguishing vanes as the gas circulates, until it is completely extinguished. Since the gas does not have to be ejected from the arc-extinguishing chamber but circulates in the arc-extinguishing chamber during the arc-extinguishing process, zero flashover can be achieved. However, the design of the backflow channel that guides the flow of the gas in the related art still needs to be optimized to be able to fully utilize each arc-extinguishing vane of the arc-extinguishing vane group.

[0027] Figure 1 An internal structure schematic diagram of the circuit breaker 100 according to an embodiment of the present disclosure is shown. Figure 2 A cross-sectional view of the circuit breaker 100 according to an embodiment of the present disclosure is shown. Figure 1 A cross-sectional view of the circuit breaker 100 according to an embodiment of the present disclosure is shown.Figure 3 A sectional view is shown. Figure 2 A partial enlarged schematic view of the left structure of the sectional view is shown. Figure 4 A sectional view is shown. Figure 1 A sectional view is shown. Figure 5 A sectional view is shown. Figure 4 A partial enlarged schematic view of the left structure of the sectional view is shown.

[0028] Referring to Figure 1 , the circuit breaker 100 comprises a housing 10, two static contacts 20, a moving contact assembly 30, two arc extinguishing devices 40, etc.

[0029] The two static contacts 20 are respectively arranged on the housing 10 and extend into the interior of the housing 10. In some embodiments, the two static contacts 20 are arranged in a diagonal line. A first end 201 of each static contact 20 extending into the interior of the housing 10 is provided with a static contact point 21, and a second end 202 of each static contact 20 outside the housing 10 is used to connect with a power source or a load.

[0030] The moving contact assembly 30 comprises a moving contact support 31 and two moving contact points 32 arranged on the moving contact support 31. In the present embodiment, the middle part of the moving contact support 31 is rotationally connected with the housing 10, forming the rotation center of the moving contact support 31. The two moving contact points 32 are arranged at the two ends of the moving contact support 31. With the rotation of the moving contact support 31, the two moving contact points 32 can abut against or separate from the two static contact points 21, thereby corresponding to the closing state and the opening state of the circuit breaker 100. In some alternative embodiments, the moving contact support 31 can drive the two moving contact points 32 to move in a translational manner to abut against or separate from the two static contact points 21.

[0031] Two communication cavities 120 are further formed in the interior of the housing 10, and the two communication cavities 120 are located on the two sides of the rotation center of the moving contact support 31 and are arranged substantially centrally symmetrically about the rotation center of the moving contact support 31. The two moving contact points 32 at the two ends of the moving contact support 31 rotate in the two communication cavities 120 respectively. Two partitions (also can be referred to as gas generating sheets) 60 containing gas generating materials can be further arranged in each communication cavity 120, and the two partitions 60 are located on the two sides of the rotation path of the moving contact point 32. The static contact point 21 is located between the two partitions 60. Two arc extinguishing chambers 110 are located on the two sides of the rotation center of the moving contact support 31, more specifically, on the two sides of the two communication cavities 120. The two arc extinguishing chambers 110 are arranged substantially centrally symmetrically about the rotation center of the moving contact support 31, and each communication cavity 120 communicates with the corresponding arc extinguishing chamber 110. The two arc extinguishing devices 40 are respectively arranged in the two arc extinguishing chambers 110.

[0032] It should be noted that although the two communication cavities 120, the two arc extinguishing chambers 110 and the two arc extinguishing devices 40 in the embodiments of the present disclosure are arranged in a substantially central symmetry, in some alternative embodiments, the two communication cavities 120, the two arc extinguishing chambers 110 and the two arc extinguishing devices 40 can also have other arrangements. For example, in some embodiments, the size of the communication cavity 120, the arc extinguishing chamber 110 and the arc extinguishing device 40 located on one side of the rotation center of the movable contact support 31 is larger than the size of the communication cavity 120, the arc extinguishing chamber 110 and the arc extinguishing device 40 located on the other side of the rotation center of the movable contact support 31.

[0033] For the convenience of description, the following mainly describes the structure of the arc extinguishing device 40 on the left side, and the structure of the arc extinguishing device 40 on the right side can be referred to the structure of the arc extinguishing device 40 on the left side. Figures 1 to 3 For the convenience of description, the following mainly describes the structure of the arc extinguishing device 40 on the left side, and the structure of the arc extinguishing device 40 on the right side can be referred to the structure of the arc extinguishing device 40 on the left side.

[0034] The arc extinguishing device 40 includes an arc extinguishing fin group 41 and two arc separation plates 42. The arc extinguishing fin group 41 can include a plurality of arc extinguishing fins stacked together. The plurality of arc extinguishing fins includes a first arc extinguishing fin 41a located at the bottom and a plurality of second arc extinguishing fins 41b stacked on the first arc extinguishing fin 41a in sequence. Among them, the first arc extinguishing fin 41a corresponds to the first end of the arc extinguishing fin group 41, and the second arc extinguishing fin 41b at the top corresponds to the second end of the arc extinguishing fin group 41. The outer peripheral wall of the plurality of arc extinguishing fins corresponds to the outer peripheral wall of the arc extinguishing fin group 41.

[0035] Referring to Figure 2 and Figure 3 , the outer peripheral wall of the arc extinguishing fin group 41 includes a first side face 411 and a second side face 412 opposite to each other, and a third side face 413 and a fourth side face 414 opposite to each other between the first side face 411 and the second side face 412. Among them, the first side face 411 faces the stationary contact 21, and the middle position of the first side face 411 can be formed with an arc extinguishing groove 410. The second side face 412 faces away from the stationary contact 21. The two arc separation plates 42 are respectively arranged on the third side face 413 and the fourth side face 414. In some embodiments, in the stacking direction (which can also be referred to as the extension direction) L of the arc extinguishing fin group 41, the length of each arc separation plate 42 is substantially consistent with the length of the arc extinguishing fin group 41. In some embodiments, one of the two arc separation plates 42 substantially covers the third side face 413 of the arc extinguishing fin group 41, and the other arc separation plate 42 substantially covers the fourth side face 414 of the arc extinguishing fin group 41. In some embodiments, the third side face 413 and the fourth side face 414 of the arc extinguishing fin group 41 and the corresponding arc separation plate 42 can also be respectively provided with a positioning frame 43, which can be used to position the position of each arc extinguishing fin.

[0036] Referring back to Figure 1In the present embodiment, the first arc-extinguishing vane 41a is adjacent to the stationary contact 21, and can also function as an arc striking piece. More specifically, the middle portion of the first arc-extinguishing vane 41a has a protrusion 411a (see FIG. 6) extending towards the stationary contact 21. Figure 3 The topmost second arc-extinguishing vane 41b is distanced from the stationary contact 21, and can be provided with an arc striking piece 70. The arc striking piece 70 extends into the communication cavity 120 to the maximum opening position of the movable contact 511. The arc striking piece 70 is clamped between two baffles 60, and can also function as a fixing piece for the baffles 60.

[0037] The second arc-extinguishing vanes 41b can have the same structure, and each of the second arc-extinguishing vanes 41b is provided with an arc-extinguishing groove on the side facing the stationary contact 21. In the present embodiment, the arc-extinguishing groove of each of the second arc-extinguishing vanes 41b is generally V-shaped, and is generally centrally provided on the side of the second arc-extinguishing vane 41b facing the stationary contact 21. The arc-extinguishing grooves of the second arc-extinguishing vanes 41b together form the arc-extinguishing groove 410 of the arc-extinguishing vane group 41. In some alternative embodiments, the arc-extinguishing groove of each of the second arc-extinguishing vanes 41b can also have other shapes, and is not limited to the V-shaped groove shown in the figures. In some alternative embodiments, the arc-extinguishing grooves of the second arc-extinguishing vanes 41b can also not be completely identical in shape.

[0038] It should be noted that in some alternative embodiments, the relative positions of the arc-extinguishing vane group 41 and the stationary contact 21 can also have other implementations. For example, in the stacking direction L of the arc-extinguishing vane group 41, the stationary contact 21 is closer to the middle position of the arc-extinguishing vane group 41. At this time, the plurality of arc-extinguishing vanes of the arc-extinguishing vane group 41 can have the same structure, and arc striking pieces 70 are provided at both ends of the arc-extinguishing vane group 41, one of which extends towards the position of the stationary contact 21, and the other of which extends towards the maximum opening position of the movable contact 511.

[0039] Referring to Figures 2 to 5 A backflow passage 50 is formed between the outer peripheral wall of the arc-extinguishing device 40 and the peripheral wall of the arc-extinguishing chamber 110, and the outlet end 51 of the backflow passage 50 is between the first side surface 411 of the arc-extinguishing vane group 41 and the stationary contact 21, i.e., the outlet end 51 is located on the upstream side of the arc-extinguishing vane group 41. In some embodiments, the distance between the outlet end 51 and the first side surface 411 of the arc-extinguishing vane group 41 is much smaller than the distance between the outlet end 51 and the stationary contact 21. In combination with reference to Figure 1 The outlet end 51 includes an open region 511 and a closed region 512, wherein the closed region 512 is closer to the stationary contact 21 than the open region 511.

[0040] In the present embodiment, taking the left arc-extinguishing chamber 110, the communication cavity 120 and the arc-extinguishing device 40 as an example, the bottom of the outlet end 51 close to the stationary contact 21 is closed to form a closed area 512. The area of the outlet end 51 above the closed area 512 is in an open state to form an open area 511. Of course, in some alternative embodiments, according to the relative position of the arc-extinguishing grid group 41 and the stationary contact 21, the positional relationship of the open area 511 and the closed area 512 also changes accordingly. For example, when the stationary contact 21 is closer to the middle position of the arc-extinguishing grid group 41, the closed area 512 can be located at the middle position of the outlet end 51, and the open area 511 is located on both sides of the closed area 512.

[0041] The arc-extinguishing process of the circuit breaker 100 of the present embodiment will be described below with reference to Figures 1 to 5 the left arc-extinguishing chamber 110.

[0042] When the moving contact 32 is separated from the stationary contact 21, an arc is generated between the moving contact 32 and the stationary contact 21. The arc heats the surrounding air, and the baffle 60 also generates a large amount of gas under the heating action of the arc, so that a large amount of high-pressure gas is gathered on the upstream side of the arc-extinguishing grid group 41. These high-pressure gases flow from the first side 411 of the arc-extinguishing grid group 41 to the downstream side of the arc-extinguishing grid group 41, and then flow along the return flow channel 50 to the outlet end 51 of the arc-extinguishing grid group 41 in the direction indicated by the dashed arrows in Figures 2 to 4 .

[0043] Referring to Figure 1 , in the process of the flow of the high-pressure gas, the arc first enters the lower half of the arc-extinguishing chamber 110 close to the stationary contact 21, so that the arc-extinguishing grids in the lower half are first filled. In combination with referring to Figure 1 , Figure 3 and Figure 5 , under the blockage of the closed area 512 of the outlet end 51, the gas returning to the outlet end 51 will be sprayed out to the upper half of the arc-extinguishing chamber 110 through the open area 511 to return to the upstream side of the arc-extinguishing grid group 41. In turn, the returning gas sprayed out of the open area 511 is continuously circulated through the arc-extinguishing grid group 41 under the pushing of the high-pressure gas on the upstream side of the arc-extinguishing grid group 41, and pushes the arc into the arc-extinguishing grids in the upper half of the arc-extinguishing chamber 110. In this way, on the one hand, it is beneficial to improve the utilization rate of the arc-extinguishing grids far away from the stationary contact 21, thereby shortening the arc time, and on the other hand, it can effectively reduce the arc back. In turn, the breaking capacity of the circuit breaker 100 provided by the present embodiment is improved, and zero arc-over can be achieved.

[0044] As mentioned above, in the related art, the length of the open area of the outlet end of the backflow channel is substantially the same as the length of the arc extinguishing grid set in the stacking direction of the arc extinguishing grid set. At the moment of separation of the moving contact 32 and the stationary contact 21, a large amount of high-pressure gas generated near the stationary contact 21 easily returns to the vicinity of the stationary contact 21 again after passing through the arc extinguishing grid set 41 along the shortest path, so that only the arc extinguishing grid set 41 adjacent to the stationary contact 21 can play an arc extinguishing role, and the arc extinguishing grid set 41 far away from the stationary contact 21 hardly plays an arc extinguishing role. In this way, on the one hand, the arc extinguishing performance of the arc extinguishing grid set 41 is not fully utilized, which may result in a long arc burning time, and on the other hand, arc backflow may occur.

[0045] The circuit breaker 100 provided by the embodiments of the present disclosure seals the area adjacent to the stationary contact 21 of the outlet end 51 of the backflow channel 50, so that the backflow gas can flow to the upstream side of the arc extinguishing grid set 41 far away from the stationary contact 51. The gas flowing out of the open area 511 of the outlet end 51 enters the arc extinguishing grid set 41 far away from the stationary contact 21 under the push of the high-pressure gas on the upstream side of the arc extinguishing grid set 41. In this way, the overall utilization rate of the arc extinguishing grid set 41 is improved, the arc burning time is shortened, and the arc backflow can be effectively improved.

[0046] In the stacking direction L of the arc extinguishing grid set 41, the closed area 512 can have a predetermined length, which can be set as needed. In some embodiments, the ratio of the predetermined length of the closed area 512 to the length of the arc extinguishing grid set 41 can be, for example, between 1 / 8 and 1 / 5.

[0047] Referring to Figure 1 , Figure 3 and Figure 5 , in some embodiments, each arc separation plate 42 includes a first bent portion 421 bent towards the first side surface 411 of the arc extinguishing grid set 41. The length of the first bent portion 421 in the stacking direction L is substantially the same as the length of the arc extinguishing grid set 41. Each spacer plate 60 has an extension portion 61 extending into the corresponding arc extinguishing chamber. The length of the extension portion 61 in the stacking direction L is substantially the same as the length of the first bent portion 421. The extension portion 61 and the corresponding first bent portion 421 form the outlet end 51 of the backflow channel 50. In this way, the outlet end 51 can be easily close to the first side surface 411 of the arc extinguishing grid set 41.

[0048] Referring to Figure 1 , Figure 4 and Figure 5 , in some embodiments, a first portion 4211 of the first bent portion 421 close to the stationary contact 21 is connected with the corresponding extension portion 61 and seals the outlet end 51, so as to easily form the closed area 512 at the outlet end 51.

[0049] In some embodiments, the first part 4211 of the first bending part 421 can be provided with a second bending part 422, which can be lapped on the corresponding extension part 61. In this way, not only the sealing effect of the sealing area 512 can be improved, but the baffle 60 can also be further fixed by the second bending part 422.

[0050] In some embodiments, the extension part 61 can also be provided with a recess 610 for receiving the second bending part 422. In this way, the relative positions of the second bending part 422 and the extension part 61 can be easily positioned, and the second bending part 422 can also be prevented from protruding relative to the surface of the baffle 60.

[0051] Referring to Figure 1 , Figure 2 and Figure 3 , in some embodiments, the second part 4212 of the first bending part 421 adjacent to the first part 4211 forms an open area 511 of the outlet end 51 with the corresponding extension part 61. The surfaces of the second part 4212 and the extension part 61 opposite to each other have arc-shaped structures, so that the return flow channel 50 is bent towards the first side 411 of the arc extinguishing vane group 41, and the open area 511 faces and is close to the first side 411 of the arc extinguishing vane group 41, so as to facilitate the gas flowing out of the open area 511 to enter the arc extinguishing vane group 41 as soon as possible.

[0052] Referring back to Figure 1 , in some embodiments, the second end of the arc extinguishing vane group 41 extends obliquely towards the direction away from the stationary contact 21, so as to increase the distance between the arc extinguishing vanes close to the second end of the arc extinguishing vane group 41 and the arc striking piece 70. In this way, the electric arc is facilitated to move along the arc striking piece 70 to the second end of the arc extinguishing vane group 41 without easily entering the arc extinguishing vane group 41 halfway, so as to facilitate to improve the utilization rate of the arc extinguishing vane group 41.

[0053] It should be noted that although the circuit breaker 100 includes two stationary contacts 21 and two movable contacts 32 in the above-mentioned embodiments of the present disclosure, in some alternative embodiments, the circuit breaker 100 can include one stationary contact and one movable contact, which is also within the protection scope of the present disclosure.

[0054] The circuit breaker 100 provided by the embodiments of the present disclosure can be, but is not limited to, a high-voltage direct-current circuit breaker. When breaking the current, a large amount of gas generated at the moment of separation of the moving contact 32 and the stationary contact 21 is circulated through the arc extinguishing vanes of the arc extinguishing vane group 41 in the arc extinguishing chamber 110 by means of the backflow channel 50. The gas flow pushes the arc generated when the moving contact 32 and the stationary contact 21 are separated to be repeatedly divided by the arc extinguishing vanes until the arc is completely extinguished. During the arc extinguishing process of the circuit breaker 100, the gas does not have to be sprayed out of the arc extinguishing chamber 110, achieving zero flying arc. In addition, the area adjacent to the stationary contact 21 of the outlet end 51 of the backflow channel 50 is closed, so that the backflow gas can flow to the upstream side of the arc extinguishing vane group 41 away from the stationary contact 51. The gas flowing out of the open area 511 of the outlet end 51 enters the arc extinguishing vanes away from the stationary contact 21 under the push of the high-pressure gas on the upstream side of the arc extinguishing vane group 41. In this way, the overall utilization rate of the arc extinguishing vane group 41 is improved, thereby shortening the arc time and effectively improving the arc back.

[0055] The above has described the embodiments of the present disclosure, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles, practical application, or technical improvement in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A circuit breaker (100), characterized by, The circuit breaker (100) comprises: a housing (10) internally provided with an arc extinguishing chamber (110); a stationary contact (20) provided on the housing (10) and comprising a stationary contact point (21) located inside the housing (10); a movable contact assembly (30) provided in the housing (10) and comprising a movable contact support (31) and a movable contact point (32) provided on the movable contact support (31), the movable contact point (32) being capable of moving with the movable contact support (31) to abut against or separate from the stationary contact point (21); and an arc extinguishing device (40) located inside the arc extinguishing chamber (110) and comprising an arc extinguishing fin set (41) and two arc separation plates (42), an outer peripheral wall of the arc extinguishing fin set (41) comprising a first side (411) and a second side (412) opposite to each other, and a third side (413) and a fourth side (414) located between the first side (411) and the second side (412) and opposite to each other, the first side (411) facing the stationary contact point (21), the two arc separation plates (42) being respectively provided on the third side (413) and the fourth side (414), and an outer peripheral wall of the arc extinguishing device (40) and a peripheral wall of the arc extinguishing chamber (110) forming a backflow channel (50), an outlet end (51) of the backflow channel (50) being located between the first side (411) of the arc extinguishing fin set (41) and the stationary contact point (21), and the outlet end (51) comprising an open area (511) and a closed area (512), the closed area (512) being close to the stationary contact point (21).

2. The circuit breaker (100) of claim 1, wherein, The housing (10) is further internally formed with a communication cavity (120) in communication with the arc extinguishing chamber (110), two separation plates (60) containing gas generating materials being provided in the communication cavity (120), the two separation plates (60) being located on both sides of a rotating path of the movable contact point (32).

3. The circuit breaker (100) according to claim 2, wherein each of the arc separation plates (42) comprises a first bending portion (421) bent towards the first side (411) of the arc extinguishing fin set (41), and each of the separation plates (60) has an extension portion (61) extending into the arc extinguishing chamber (110), the extension portion (61) and the corresponding first bending portion (421) forming the outlet end (51) of the backflow channel (50).

4. The circuit breaker (100) according to claim 3, wherein a first portion (4211) of the first bending portion (421) close to the stationary contact point (21) is connected with the corresponding extension portion (61) to form the closed area (512), and a second portion (4212) of the first bending portion (421) adjacent to the first portion (4211) forms the open area (511) with the corresponding extension portion (61).

5. The circuit breaker (100) of claim 4, wherein, The second part (4212) of the first bent part (421) and the surface opposite to each other of the corresponding extension part (61) have arc-shaped structures respectively, so that the open area (511) faces the first side (411) of the arc-extinguishing fin group (41).

6. The circuit breaker (100) of claim 4, wherein, The first part (4211) of the first bent part (421) is provided with a second bent part (422) which overlaps on the corresponding extension part (61).

7. The circuit breaker (100) of claim 6, wherein, The extension part (61) is provided with a recess (610) for receiving the second bent part (422).

8. The circuit breaker (100) of claim 2, wherein, The first end of the arc-extinguishing fin group (41) is close to the static contact (21), and the second end of the arc-extinguishing fin group (41) extends obliquely towards the direction away from the static contact (21).

9. The circuit breaker (100) of claim 8, wherein, The second end of the arc-extinguishing fin group (41) is provided with an arc striking piece (70) which extends into the communication cavity (120) and is clamped between the two partitions (60).

10. The circuit breaker (100) according to claim 8, characterized in that, The arc-extinguishing fin group (41) comprises a plurality of arc-extinguishing fins which are stacked together, the plurality of arc-extinguishing fins comprising a first arc-extinguishing fin (41a) adjacent to the static contact (21) and a plurality of second arc-extinguishing fins (41b) which are sequentially stacked on the first arc-extinguishing fin (41a), and The middle part of the first arc-extinguishing fin (41a) has a protruding part (411a) which extends towards the static contact (21), and each of the second arc-extinguishing fins (41b) is provided with an arc-extinguishing groove.

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