Arc extinguishing structure and circuit breaker

Abstract

The arc extinguishing structure comprises a housing and an arc extinguishing chamber installed in the housing, one side, close to the contact mechanism, of the arc extinguishing chamber is an arc inlet side, the other side of the arc extinguishing chamber is an exhaust side, an exhaust channel is arranged between an exhaust port of the housing and the exhaust side of the arc extinguishing chamber, at least one backflow prevention channel is arranged in the exhaust channel, and an opening of the backflow prevention channel faces the exhaust port. And the flow of the forward gas flowing to the exhaust port is unobstructed, and the flow of the reverse gas flowing to the arc extinguish chamber is obstructed. The circuit breaker comprises an operating mechanism, a contact mechanism and an arc extinguishing structure. According to the arc extinguishing structure and the circuit breaker, the flow direction of gas flowing out of the anti-backflow channel is the same as that of gas in the exhaust channel during exhaust, the flow speed of the gas in the exhaust channel is accelerated, the gas is rapidly exhausted, and the flow direction of the gas flowing out of the anti-backflow channel is opposite to that of the gas in the exhaust channel during gas recharge, so that the gas is rapidly exhausted. The flow rate of the gas in the exhaust channel is slowed down, gas recharge is reduced, and the breaking capacity of the circuit breaker is improved.

Description

Technical Field

[0001] The utility model relates to the field of low-voltage electrical appliances, in particular to an arc extinguishing structure and a circuit breaker. Background Art

[0002] When a circuit breaker trips, an arc forms between the moving and stationary contacts. After the arc is extinguished by the arc-extinguishing chamber, a large amount of high-temperature gas is generated. Smooth exhaust of this high-temperature gas is crucial. Due to the sealed casing of existing circuit breakers, the gas pressure at the gas outlet is higher than that at the contact side during the tripping process. This results in gas backflow and back-spray, hindering the circuit breaker's tripping performance. Summary of the Invention

[0003] The purpose of the utility model is to overcome at least one defect of the prior art and provide an arc extinguishing structure and a circuit breaker.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] The arc extinguishing structure includes a cover shell and an arc extinguishing chamber installed in the cover shell. The side of the arc extinguishing chamber close to the contact mechanism is the arc input side, and the other side is the exhaust side. The contact mechanism includes matching moving contacts and static contacts. An exhaust channel is provided between the exhaust port of the cover shell and the exhaust side of the arc extinguishing chamber. At least one anti-backflow channel is provided in the exhaust channel. The opening of the anti-backflow channel is arranged toward the exhaust port, so as to ensure unobstructed forward gas flow to the exhaust port and obstructed reverse gas flow to the arc extinguishing chamber.

[0006] Optionally, the exhaust channel is formed between the two opposite first side walls of the cover shell, and the anti-backflow channel is arranged in a row along the length direction of the exhaust channel. The exhaust channel is provided with partitions and blocking plates that are alternately arranged along the length direction of the exhaust channel, one end of the partition is connected to the first side wall, and the other end is biased toward the exhaust port and deviates from the arc extinguishing chamber. One end of the blocking plate is spaced apart from the first side wall, and the other end is biased toward the exhaust port and deviates from the arc extinguishing chamber. The anti-backflow channel is formed between the blocking plate, the first side wall and the partition.

[0007] Optionally, the partition and the blocking plate are arranged in parallel.

[0008] Optionally, the partition and the blocking plate are parallelogram plates, the end faces of the partition and the end faces of the blocking plate are respectively arranged parallel to the first side wall, and the side faces of the partition and the side faces of the blocking plate are parallel to each other.

[0009] Optionally, the anti-reflux channels are arranged in two rows, the two rows of anti-reflux channels are respectively arranged along the two first side walls, and the two rows of anti-reflux channels are symmetrically arranged; or, the blocking plates and partitions of the two rows of anti-reflux channels are staggered.

[0010] Optionally, a V-shaped bending plate is provided in the exhaust channel, and the bending plate encloses the anti-backflow channel.

[0011] Optionally, the arc extinguishing chamber is arranged between two opposite first side walls of the cover shell, and a first arc striking angle is provided between the arc extinguishing chamber and the first side wall above. The first arc striking angle extends from the exhaust side of the arc extinguishing chamber to above the disconnecting position of the moving contact and exceeds the moving contact point of the moving contact. The moving contact contacts the first arc striking angle when it is disconnected from the static contact.

[0012] Optionally, the moving contact has an abutment surface opposite to the side where the moving contact is located, and the end of the first arcing angle has a contact surface on the side facing the moving contact, and the abutment surface fits with the contact surface of the first arcing angle when the moving contact is disconnected from the static contact.

[0013] Optionally, it also includes two magnetic conductive plates and two gas production plates arranged on the arc entry side of the arc extinguishing chamber, the two gas production plates are located on both sides of the moving contact, and the two magnetic conductive plates are respectively located between the two gas production plates and the two side walls opposite to the cover.

[0014] The circuit breaker comprises an operating mechanism and a contact mechanism, wherein the operating mechanism is connected to the movable contact of the contact mechanism and can drive the movable contact to swing and disconnect or close with the static contact, and also comprises any arc extinguishing structure described in any one of the items.

[0015] Optionally, it also includes a magnetic system, which includes a bracket, an armature rotatably set on the bracket, an iron core fixed on the bracket and arranged opposite to the armature, and a reset spring that provides elastic reset force for the armature, a through cavity for the static contact to pass through between the iron core and the armature, and a trip arm for driving the operating mechanism to trip.

[0016] Optionally, the bracket and the armature are two U-shaped structures with openings arranged opposite to each other, the two side edges of the armature are rotatably arranged on the inner sides of the two side edges of the bracket, the iron core is fixed on the inner side of the bottom edge of the bracket, and is arranged opposite to the two side edges of the armature at intervals, and a connecting hole for connecting a reset spring is provided on the bottom edge of the armature, one end of the reset spring is hung in the connecting hole, and the other end is hung on the connecting column of the cover shell.

[0017] Optionally, the operating mechanism includes a movably arranged handle, a contact support rotatably arranged in the cover housing, a contact spring connected between the contact support and the moving contact and providing contact pressure for the moving contact, a lock and a jump lock respectively rotatably arranged on the contact support and snap-connected, the handle is drive-connected to the lock, the contact support is coaxially arranged with the moving contact, and is provided with an accommodating cavity for accommodating the moving contact, one end of the moving contact is located in the accommodating cavity, and the other end extends out of the accommodating cavity and is provided with a moving contact that cooperates with the static contact of the static contact.

[0018] The arc extinguishing structure and circuit breaker of the present invention have the following characteristics: when exhausting, the gas flowing out of the anti-backflow channel has the same flow direction as the gas in the exhaust channel, which accelerates the gas flow rate of the exhaust channel and makes the gas discharged quickly; when the gas is re-injected, the gas flowing out of the anti-backflow channel flows in the opposite direction to the gas in the exhaust channel, which hinders the gas in the exhaust channel and slows down its flow rate, reduces gas re-injection, and is beneficial to improving the breaking capacity of the circuit breaker.

[0019] In addition, the anti-backflow channel is designed in a fin shape with a simple structure, which further accelerates exhaust and reduces gas backflow. Moreover, the anti-backflow channel is set along the side wall of the exhaust channel, so that a large flow of positive gas can be discharged along the exhaust channel, facilitating rapid gas discharge.

[0020] In addition, when the moving contact is disconnected, it contacts the first arcing angle, so that the first arcing angle and the moving contact are in an equipotential state, making it easier for the arc to transfer toward the first arcing angle, and thus guided into the arc extinguishing chamber through the first arcing angle, thereby improving the arc extinguishing effect.

[0021] In addition, the return spring is arranged on the outside of the armature, which simplifies the structure of the magnetic system and makes the layout between the bracket, the armature, the iron core and the static contact more compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the gas flow direction during exhaust of the structure inside the housing of the first embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the gas flow direction during gas re-injection in the housing structure of the first embodiment of the present invention;

[0024] Figure 3 It is a structural diagram of the shell of the utility model;

[0025] Figure 4 This is an assembly drawing of the half shell and the cover shell of the utility model;

[0026] Figure 5 It is a structural diagram of the cover of the utility model;

[0027] Figure 6 This is a structural diagram of a cover base according to a first embodiment of the present invention;

[0028] Figure 7 This is a structural diagram of the cover base of the second embodiment of the present utility model;

[0029] Figure 8 This is a structural diagram of the cover base of the third embodiment of the present utility model;

[0030] Figure 9 It is a cross-sectional view of the circuit breaker of the utility model;

[0031] Figure 10It is a structural diagram of the lock buckle of the utility model;

[0032] Figure 11 It is a structural diagram of the jump buckle of the utility model;

[0033] Figure 12 This is a structural diagram of the driving wheel of the utility model from one perspective;

[0034] Figure 13 This is a structural diagram of the driving wheel of the utility model from another perspective;

[0035] Figure 14 It is a structural diagram of the transmission gear of the utility model.

[0036] Housing 1; exhaust hole 101; cover 2; exhaust port 201; first side wall 202; exhaust channel 203; anti-backflow channel 204; partition 205; blocking plate 206; connecting column 207; limiting cavity 208; stopper 209; first stopper surface 209a; second stopper surface 209b; first slot 209c; bending plate 210; arc extinguishing chamber 3; first arcing angle 4; contact surface 401; moving contact 5; moving contact point 501; abutting surface 502; static contact 6; U-shaped portion 601; contact end 602; static contact 603; fixed end 6 04; magnetic system 7; bracket 71; armature 72; trip arm 721; iron core 73; reset spring 74; operating mechanism 8; contact support 81; limiting protrusion 811; contact spring 82; lock 83; first lap surface 831; jump buckle 84; second lap surface 841; hook 842; release surface 843; driving wheel 85; first mating surface 851; second mating surface 852; second slot 853; driving slot 854; second connecting rod 86; magnetic conductive plate 9; gas production plate 10; second arc striking angle 11; transmission gear 12; driving part 121. DETAILED DESCRIPTION

[0037] The following embodiments are given in conjunction with the accompanying drawings to further illustrate the specific implementation of the arc extinguishing structure and circuit breaker of the present invention. The arc extinguishing structure and circuit breaker of the present invention are not limited to the description of the following embodiments.

[0038] like Figure 1 and Figure 2 As shown, the circuit breaker of this embodiment includes a cover 2, an operating mechanism 8 installed in the cover 2, a contact mechanism and an arc extinguishing structure. The contact mechanism includes a matching moving contact 5 and a static contact 6. The operating mechanism 8 is connected to the moving contact 5 of the contact mechanism. The operating mechanism 8 can drive the moving contact 5 to swing and disconnect from the static contact 6 to achieve circuit breaker opening; the operating mechanism 8 can drive the moving contact 5 to swing and close with the static contact 6 to achieve circuit breaker closing.

[0039] like Figure 1 and Figure 2As shown, the arc extinguishing structure of this embodiment includes an arc extinguishing chamber 3, which is arranged between the two opposite first side walls 202 of the housing 2 and is used to extinguish the arc generated during the opening and closing of the moving contact 5 and the static contact 6. The side of the arc extinguishing chamber 3 close to the contact mechanism is the arc entry side, and the other side is the exhaust side. Figure 4 and Figure 5 As shown, the cover 2 includes a base and a cover plate that cover each other. The cover plate of the cover 2 is provided with an exhaust port 201 on a side close to the exhaust side of the arc extinguishing chamber 3 and away from the arc inlet side of the arc extinguishing chamber 3. The cover 2 is installed in the housing 1. Figure 3 As shown, the housing 1 comprises two half shells that cover each other, and exhaust holes 101 are provided on the side walls of the two half shells of the housing 1 near the exhaust port 201. Figure 1 and Figure 2 As shown, an exhaust channel 203 is provided between the exhaust port 201 of the housing 2 and the exhaust side of the arc extinguishing chamber 3. Figure 1 As shown, the arc will generate high temperature gas after entering the arc extinguishing chamber 3 from the arc entry side. The gas will be discharged from the arc extinguishing chamber 3 from the exhaust side of the arc extinguishing chamber, and then pass through the exhaust channel 203 and then from the exhaust port 201 ( Figure 4 ) is discharged from the housing 2 and finally from the exhaust hole 101 ( Figure 3 )discharge.

[0040] The improvement of this application is that Figure 1 and Figure 2 As shown, at least one anti-backflow channel 204 is provided in the exhaust channel 203. The anti-backflow channel 204 is a one-way valve structure. The opening of the anti-backflow channel 204 is set toward the exhaust port 201, so as to allow the forward gas flow to the exhaust port 201 to be unobstructed and the reverse gas flow to the arc extinguishing chamber 3 to be blocked. Figure 1 As shown, when the gas flowing out of the arc extinguishing chamber 3 is discharged from the exhaust port 201 along the exhaust channel 203, the gas flowing out of the anti-backflow channel 204 has the same flow direction as the gas in the exhaust channel 203, accelerating the gas flow rate of the exhaust channel 203 and allowing the gas to be discharged quickly; Figure 2 As shown, when the gas flows back into the arc extinguishing chamber 3 along the exhaust channel 203 in the reverse direction, the returned gas passes through the anti-backflow channel 204 and then flows back to the exhaust port 201, so that the gas flowing out of the anti-backflow channel 204 is opposite to the gas flow of the exhaust channel 203, hindering the gas in the exhaust channel 203 to slow down its flow rate, reducing gas backflow, and helping to improve the breaking capacity of the circuit breaker.

[0041] like Figure 1 、 Figure 2 and Figure 6 The embodiment 1 shown and Figure 7The specific structure of the backflow prevention channel 204 of the second embodiment is shown. The exhaust channel 203 is formed between the two opposing first side walls 202 of the housing 2. The backflow prevention channels 204 are arranged in a row along the length of the exhaust channel 203. The exhaust channel 203 is provided with partitions 205 and baffles 206 that are alternately spaced along the length of the exhaust channel 203. Preferably, the partitions 205 and baffles 206 are arranged in parallel. One end of the partition 205 is connected to the first side wall 202, and the other end is offset toward the exhaust port 201 and away from the arc extinguishing chamber 3. One end of the baffle 206 is spaced from the first side wall 202, and the other end is offset toward the exhaust port 201 and away from the arc extinguishing chamber 3. That is, the partitions 205 and baffles 206 are both inclined toward the exhaust port 201 and away from the arc extinguishing chamber 3. The baffles 206, the first side wall 202, and the partition 205 form an inclined U-shaped, fin-like, backflow prevention channel 204. The anti-backflow channel 204 is designed in a fin shape with a simple structure, which further accelerates exhaust and reduces gas backflow. Moreover, the anti-backflow channel 204 is arranged along the side wall of the exhaust channel 203, so that a large flow of positive gas can be discharged along the exhaust channel 203, facilitating rapid gas discharge.

[0042] like Figure 1 、 Figure 2 and Figure 6 The embodiment 1 shown and Figure 7 The anti-reflux channels 204 of the second embodiment are arranged in two rows, and the two rows of anti-reflux channels 204 are respectively arranged along the two first side walls 202. Each row of anti-reflux channels 204 can be provided with one or more anti-reflux channels 204. Figure 6 As shown, in the first embodiment, the two rows of anti-backflow channels 204 are symmetrically arranged, that is, the blocking plates 206 and the partitions 205 of the two rows of anti-backflow channels 204 are symmetrically arranged; preferably, the other end of the partition 205 and the other end of the blocking plate 206 are arranged flush along the length direction of the exhaust channel 203. Alternatively, as Figure 7 As shown, in the second embodiment, the blocking plates 206 and the partitions 205 of the two rows of anti-reflux channels 204 are staggered; preferably, the other end of the partition 205 in the same row protrudes from the other end of the blocking plate 206. Of course, the anti-reflux channels 204 can also be arranged in a row, with the row of anti-reflux channels 204 being arranged along one of the first side walls 202.

[0043] Specifically, the partition plate 205 and the blocking plate 206 are parallelogram-shaped plates integrally formed on the housing 2. The end faces of the partition plate 205 and the adjacent side faces form non-perpendicular angles, either obtuse or acute. The end faces of the blocking plate 206 and the adjacent side faces form non-perpendicular angles, either obtuse or acute. The end faces of the partition plate 205 and the blocking plate 206 are respectively parallel to the first sidewall 202, and the side faces of the partition plate 205 and the blocking plate 206 are mutually parallel. The partition plate 205 and the blocking plate 206 have a simple structure, facilitating integral molding with the housing 2.

[0044] like Figure 8 The specific structure of the backflow prevention channel 204 of the third embodiment is shown. A V-shaped bent plate 210 is provided within the exhaust channel 203. The bent plate 210 forms the backflow prevention channel 204. The V-shaped opening of the bent plate 210 faces the exhaust port 201 and faces away from the arc extinguishing chamber 3. One or more bent plates 210 may be provided, and the bent plates 210 are arranged in one or more rows within the exhaust channel 203. The bent plates 210 are arranged at an oblique angle to the longitudinal direction of the exhaust channel 203. Of course, the bent plates 210 may also have other shapes, such as a U-shape or a W-shape.

[0045] like Figure 1 and Figure 2 As shown, a first arcing angle 4 is provided between the arc extinguishing chamber 3 and the upper first sidewall 202. The first arcing angle 4 extends from the exhaust side of the arc extinguishing chamber 3 to above the disconnection position of the movable contact 5 and exceeds the movable contact point 501 of the movable contact 5. When the movable contact 5 is disconnected from the static contact 6, it contacts the first arcing angle 4. Specifically, the movable contact 5 has an abutment surface 502 opposite the side where the movable contact point 501 is located. The end of the first arcing angle 4 facing the movable contact 5 has a contact surface 401. When the movable contact 5 is disconnected from the static contact 6, the abutment surface 502 abuts the contact surface 401 of the first arcing angle 4. When the movable contact 5 is disconnected, it contacts the first arcing angle 4, placing the first arcing angle 4 and the movable contact 5 at the same potential. This makes it easier for the arc to transfer toward the first arcing angle 4, and thus, it is guided into the arc extinguishing chamber 3 by the first arcing angle 4, thereby improving the arc extinguishing effect.

[0046] like Figure 1 and Figure 2As shown, a second arcing angle 11 is provided between the arc extinguishing chamber 3 and the first side wall 202 below. The second arcing angle 11 extends from the exhaust side of the arc extinguishing chamber 3 to the static contact 603 of the static contact 6. The static contact 6 includes a U-shaped portion 601 having two opposing sides and a bottom edge connected between the two sides and opposite to the opening. One side of the U-shaped portion 601 extends to form a fixed end 604 fixed to the housing 2, and the other side of the U-shaped portion 601 is bent inward to form an inclined contact end 602. The outer side of the contact end 602 is provided with a static contact 603 that cooperates with the movable contact 501 of the movable contact 5.

[0047] like Figure 1 、 Figure 2 and Figure 9 As shown, the arc extinguishing structure of this embodiment further includes two magnetic conductive plates 9 and two gas-generating plates 10 disposed on the arc-entry side of the arc extinguishing chamber 3. The two gas-generating plates 10 are located on either side of the moving contact 5, and the two magnetic conductive plates 9 are respectively located between the two gas-generating plates 10 and the two opposing side walls of the housing 2. The gas-generating plates 10 and magnetic conductive plates 9 on the same side are stacked and mounted on the side walls of the housing 2. The magnetic conductive plates 9 facilitate arc transfer, and the gas-generating plates 10 are made of a gas-generating material that generates gas to cool and blow the arc, thereby improving arc extinguishing effectiveness.

[0048] like Figure 1 and Figure 2As shown, the circuit breaker of this embodiment also includes a magnetic system 7, which includes a bracket 71, an armature 72 rotatably mounted on the bracket 71, an iron core 73 fixed to the bracket 71 and disposed opposite the armature 72, and a return spring 74 that provides elastic return force to the armature 72. A through cavity for the static contact 6 to pass through is defined between the iron core 73 and the armature 72. The armature 72 is provided with a tripping arm 721 for driving the operating mechanism 8 to trip. The iron core 73 can increase the repulsive force to quickly repel the movable contact 5, and can also serve as the core 73 of the magnetic system 7 to attract the armature 72, causing the circuit breaker to trip. Specifically, the bracket 71 and armature 72 are two U-shaped structures arranged with openings facing each other, each having opposing sides and a bottom edge connected between the sides and opposite the opening. The sides of the armature 72 are pivotally mounted on the inner sides of the bracket 71. The iron core 73 is fixed to the inner side of the bottom edge of the bracket 71 and spaced apart from the edges of the armature 72 to achieve an engaged engagement. The bottom edge of the U-shaped portion 601 of the static contact 6 passes through the cavity between the iron core 73 and the armature 72, and the iron core 73 is located within the opening of the U-shaped portion 601. The bottom edge of the armature 72 is provided with a connection hole for connecting a return spring 74. One end of the return spring 74 is mounted in the connection hole, and the other end is mounted on the connection post 207 of the housing 2. The return spring 74 is arranged outside the armature 72, simplifying the structure of the magnetic system 7 and making the layout of the bracket 71, armature 72, iron core 73, and static contact 6 more compact.

[0049] like Figure 1 、 Figure 2 、 Figure 10 and Figure 11 As shown, the operating mechanism 8 of this embodiment includes a movable handle, a contact support 81 rotatably set in the cover shell 2, a contact spring 82 connected between the contact support 81 and the moving contact 5 and providing contact pressure for the moving contact 5, a lock 83 and a jump lock 84 rotatably set on the contact support 81 and snap-connected, the handle is drivingly connected to the lock 83, the contact support 81 is coaxially set with the moving contact 5, and is provided with an accommodating cavity for accommodating the moving contact 5, one end of the moving contact 5 is located in the accommodating cavity, and the other end extends out of the accommodating cavity and is provided with a moving contact 501 that cooperates with the static contact 603 of the static contact 6. The lock buckle 83 is provided with a first overlapping surface 831; the jump buckle 84 is provided with a second overlapping surface 841 for being connected with the first overlapping surface 831 of the lock buckle 83, a hook 842 and a release surface 843 for driving and cooperating with the release arm 721 of the armature 72, and a first torsion spring is provided between the jump buckle 84 and the contact support 81 to provide an elastic reset force for the jump buckle 84, one end of the first torsion spring is connected to the hook 842 of the jump buckle 84, and the other end is connected to the limiting protrusion 811 of the contact support 81.

[0050] like Figure 1 、 Figure 6 and Figure 12 As shown, the circuit breaker of this embodiment also includes an automatic reclosing mechanism and a driving wheel 85 that is rotatably arranged in the limiting cavity 208 of the cover 2 and is linked to the handle. The automatic reclosing mechanism is driven and connected to the driving wheel 85 through a transmission assembly, and the handle is driven and connected to the lock 83 through the driving wheel 85. The driving wheel 85 is linked to the handle through a first connecting rod, and the two ends of the first connecting rod are respectively hinged to the driving wheel 85 and the handle. The driving wheel 85 is linked to the lock 83 through a second connecting rod 86, and the two ends of the second connecting rod 86 are respectively hinged to the driving wheel 85 and the lock 83. It should be noted that the circuit breaker of this embodiment has a manual opening and closing mode achieved by a manual operating handle and an automatic opening and closing mode achieved by the automatic reclosing mechanism. In the automatic opening and closing mode, the stopping of the opening and closing process depends on the micro switch. The structure and principle of the automatic reclosing mechanism are prior art and will not be repeated here. Obviously, the circuit breaker of this embodiment can be provided with no automatic reclosing mechanism and only has a manual opening and closing mode.

[0051] like Figure 6 and Figure 12 As shown, a protruding stopper 209 for limiting the rotational travel of the driving wheel 85 is provided on the inner wall of the limiting cavity 208 of the housing 2. The stopper 209 has a first stopper surface 209a and a second stopper surface 209b located on both sides. The driving wheel 85 has a first mating surface 851 mating with the first stopper surface 209a and a second mating surface 852 mating with the second stopper surface 209b. A second torsion spring is provided between the driving wheel 85 and the housing 2 to provide an elastic restoring force for the driving wheel 85. One end of the second torsion spring is inserted into the first slot 209c of the housing 2, and the other end is inserted into the second slot 853 of the driving wheel 85. Figure 13 and Figure 14 As shown, the transmission assembly includes a transmission gear 12 coaxially arranged with the driving wheel 85, and the transmission gear 12 is drivingly connected to the driving wheel 85. The transmission gear 12 is provided with a driving portion 121, and the driving portion 121 extends into the limiting cavity 208 and is clamped into the driving groove 854 of the driving wheel 85.

[0052] During the manual closing process of the circuit breaker of this embodiment, the operating handle is moved to the closing position. The handle rotates the driving wheel 85 through the first connecting rod, and the driving wheel 85 drives the lock catch 83 through the second connecting rod. The lock catch 83 and the trip catch 84 are in a snap-fitting engagement, causing the moving contact 5 to rotate and close the static contact 6. The second mating surface 852 of the driving wheel 85 and the second stop surface 209b of the cover 2 are limited and engaged to stop.

[0053] During the manual opening process of the circuit breaker of this embodiment, the handle is operated to the opening position. The handle rotates the driving wheel 85 in the opposite direction via the first connecting rod. The driving wheel 85 drives the lock catch 83 via the second connecting rod. The lock catch 83 and the trip catch 84 engage with each other, causing the moving contact 5 to rotate and disconnect from the static contact 6. The first mating surface 851 of the driving wheel 85 engages with the first stop surface 209a of the cover 2 to stop the moving contact 5. Because the driving wheel 85 is drivingly connected to the transmission gear, the automatic reclosing mechanism can realize the automatic reclosing function.

[0054] During the tripping process of the circuit breaker of this embodiment, when a short-circuit current appears in the main circuit of the circuit breaker, the armature 72 rotates and engages with the iron core 73, causing the tripping arm 721 of the armature 72 to strike the tripping surface 843 of the tripping latch 84. The tripping latch 84 rotates and releases the lock latch 83, disconnecting the moving contact 5 from the static contact 6, thereby tripping the circuit breaker.

[0055] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, or are conventionally placed directions or positional relationships during use. They are intended solely for ease of description and do not imply that the devices or components referred to must have a specific direction. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used solely for distinction and description and should not be construed as indicating relative importance.

[0056] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. An arc extinguishing structure, comprising a housing (2) and an arc extinguishing chamber (3) installed in the housing (2), wherein the side of the arc extinguishing chamber (3) close to the contact mechanism is an arc-entry side, and the other side is an exhaust side, the contact mechanism includes a matching moving contact (5) and a static contact (6), an exhaust channel (203) is provided between the exhaust port (201) of the housing (2) and the exhaust side of the arc extinguishing chamber (3), and is characterized in that: At least one backflow prevention channel (204) is provided in the exhaust channel (203), and the opening of the backflow prevention channel (204) is arranged toward the exhaust port (201), so as to allow the forward gas flow toward the exhaust port (201) to be unobstructed and the reverse gas flow toward the arc extinguishing chamber (3) to be obstructed.

2. The arc extinguishing structure according to claim 1, characterized in that: The exhaust channel (203) is formed between two opposite first side walls (202) of the housing (2); the anti-backflow channel (204) is arranged in a row along the length direction of the exhaust channel (203); a partition (205) and a blocking plate (206) are provided in the exhaust channel (203) and are alternately arranged along the length direction of the exhaust channel (203); one end of the partition (205) is connected to the first side wall (202), and the other end is biased toward the exhaust port (201) and is arranged away from the arc extinguishing chamber (3); one end of the blocking plate (206) is spaced from the first side wall (202), and the other end is biased toward the exhaust port (201) and is arranged away from the arc extinguishing chamber (3); the anti-backflow channel (204) is formed between the blocking plate (206), the first side wall (202) and the partition (205).

3. The arc extinguishing structure according to claim 2, characterized in that: The partition plate (205) and the blocking plate (206) are arranged in parallel.

4. The arc extinguishing structure according to claim 2, characterized in that: The partition (205) and the blocking plate (206) are parallelogram plates, the end faces of the partition (205) and the end faces of the blocking plate (206) are respectively arranged parallel to the first side wall (202), and the side faces of the partition (205) and the side faces of the blocking plate (206) are parallel to each other.

5. The arc extinguishing structure according to any one of claims 2 to 4, characterized in that: The anti-reflux channels (204) are arranged in two rows, the two rows of anti-reflux channels (204) are respectively arranged along the two first side walls (202), and the two rows of anti-reflux channels (204) are symmetrically arranged; or, the blocking plates (206) and the partitions (205) of the two rows of anti-reflux channels (204) are staggered.

6. The arc extinguishing structure according to claim 1, characterized in that: A V-shaped bending plate (210) is provided in the exhaust channel (203), and the bending plate (210) encloses the anti-backflow channel (204).

7. The arc extinguishing structure according to claim 1, characterized in that: The arc extinguishing chamber (3) is arranged between two opposite first side walls (202) of the housing (2); a first arc striking angle (4) is provided between the arc extinguishing chamber (3) and the upper first side wall (202); the first arc striking angle (4) extends from the exhaust side of the arc extinguishing chamber (3) to above the disconnection position of the moving contact (5) and exceeds the moving contact point (501) of the moving contact (5); the moving contact (5) contacts the first arc striking angle (4) when disconnected from the static contact (6).

8. The arc extinguishing structure according to claim 7, characterized in that: The moving contact (5) has an abutting surface (502) opposite to the side where the moving contact (501) is located, and the end of the first arc striking angle (4) has a contact surface (401) on the side facing the moving contact (5). When the moving contact (5) is disconnected from the static contact (6), the abutting surface (502) is in contact with the contact surface (401) of the first arc striking angle (4).

9. The arc extinguishing structure according to claim 1, characterized in that: It also includes two magnetic conductive plates (9) and two gas-generating plates (10) arranged on the arc-entry side of the arc-extinguishing chamber (3), the two gas-generating plates (10) being located on both sides of the moving contact (5), and the two magnetic conductive plates (9) being respectively located between the two gas-generating plates (10) and two side walls opposite to the cover (2).

10. A circuit breaker comprising an operating mechanism (8) and a contact mechanism, wherein the operating mechanism (8) is connected to a movable contact (5) of the contact mechanism and is capable of driving the movable contact (5) to swing and disconnect or close with a stationary contact (6), and is characterized in that: It also includes the arc extinguishing structure according to any one of claims 1 to 9.

11. The circuit breaker according to claim 10, wherein: The invention also includes a magnetic system (7), wherein the magnetic system (7) includes a bracket (71), an armature (72) rotatably arranged on the bracket (71), an iron core (73) fixed on the bracket (71) and arranged opposite to the armature (72), and a reset spring (74) providing elastic reset force for the armature (72); a through cavity for the static contact (6) to pass through is provided between the iron core (73) and the armature (72); and a tripping arm (721) for driving the operating mechanism (8) to trip is provided on the armature (72).

12. The circuit breaker according to claim 11, wherein: The bracket (71) and the armature (72) are two U-shaped structures with openings arranged opposite to each other. The two side edges of the armature (72) are rotatably arranged on the inner sides of the two side edges of the bracket (71). The iron core (73) is fixed on the inner side of the bottom edge of the bracket (71) and is arranged opposite to the two side edges of the armature (72) at intervals. A connecting hole for connecting a reset spring (74) is provided on the bottom edge of the armature (72). One end of the reset spring (74) is hung in the connecting hole, and the other end is hung on the connecting column (207) of the cover shell (2).

13. The circuit breaker according to claim 10, wherein: The operating mechanism (8) includes a movable handle, a contact support (81) rotatably arranged in the cover (2), a contact spring (82) connected between the contact support (81) and the moving contact (5) and providing contact pressure for the moving contact (5), a lock (83) and a jump lock (84) rotatably arranged on the contact support (81) and connected by snapping, the handle and the lock (83) are drivingly connected, the contact support (81) is coaxially arranged with the moving contact (5), and is provided with an accommodating cavity for accommodating the moving contact (5), one end of the moving contact (5) is located in the accommodating cavity, and the other end extends out of the accommodating cavity and is provided with a moving contact (501) that cooperates with the static contact (603) of the static contact (6).

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