Circuit breaker

Abstract

A circuit breaker comprises a shell, an arc extinguish chamber and an arc striking chamber, the arc extinguish chamber and the arc striking chamber are arranged in the shell, the arc striking chamber comprises two arc isolating pieces which are oppositely arranged, an arc striking channel is formed between the two arc isolating pieces, the shell comprises two side plates, the two side plates are arranged on the side faces, away from the arc striking channel, of the two arc isolating pieces respectively, and the two side plates are arranged on the side faces, away from the arc striking channel, of the two arc isolating pieces respectively. At least one side plate is provided with a supporting wall, a flow guide cavity is defined by the supporting wall, the side plates and the arc isolating piece, the flow guide cavity and the arc striking channel are oppositely arranged on the two sides of the arc isolating piece, and the flow guide cavity is provided with an air inlet communicated with the arc striking channel and an air outlet communicated with an arc extinguish chamber. When the air pressure of the gas generated by breaking of the circuit breaker is high, the gas can enter the flow guide cavity under the driving of the air pressure difference, the high-temperature and high-pressure gas generated at the breaking moment is prevented from being all concentrated in the arc striking channel, and the gas enters the arc extinguish chamber to be extinguished after being cooled and subjected to auxiliary pressure relief through the flow guide cavity.

Description

Technical Field

[0001] The invention relates to the field of low-voltage electrical appliances, and in particular to a circuit breaker. Background Art

[0002] Circuit breakers are often used to control the on and off of lines, and the arcs generated when the lines are on and off need to be extinguished quickly. However, the existing circuit breakers have a single airflow channel, and the high-temperature, high-pressure gas and arcs generated during disconnection are difficult to be quickly cooled and discharged through the arc-strike channel and arc-extinguishing chamber, and the medium recovery is relatively slow, which is not conducive to fast and efficient arc extinguishing. Summary of the invention

[0003] The purpose of the present invention is to overcome at least one defect of the prior art and provide a circuit breaker.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A circuit breaker comprises a shell and an arc extinguishing chamber and an arc striking chamber respectively arranged in the shell, the arc striking chamber comprising two arc-isolating members arranged opposite to each other, an arc striking channel being formed between the two arc-isolating members, the shell comprising two side plates, the two side plates being respectively arranged on the sides of the two arc-isolating members away from the arc striking channel, at least one of the side plates being provided with a supporting wall, a flow guiding cavity being formed between the supporting wall, the side plates and the arc-isolating members, the flow guiding cavity and the arc striking channel being arranged opposite to each other on two sides of the arc-isolating member, the flow guiding cavity being provided with an air inlet connected to the arc striking channel, and an air outlet connected to the arc extinguishing chamber.

[0006] Preferably, a magnetic conductive plate is provided in the flow guiding cavity, and the magnetic conductive plate is used to generate a magnetic field that attracts the arc to move toward the arc extinguishing chamber.

[0007] Preferably, a guide plate is provided in the guide cavity for dividing the guide cavity to form a plurality of guide channels, and the guide channels are connected between the air inlet and the air outlet of the guide cavity.

[0008] Preferably, a supporting structure is provided between the side plate and the arc-isolating member, so that the side plate and the arc-isolating member are spaced apart.

[0009] Preferably, the supporting structure is located at an end corner of the arc-isolating member adjacent to the static contact and the arc-extinguishing chamber, and the middle portion of the guide plate protrudes toward the side away from the supporting structure to form a transition section with a curved surface shape; a plurality of the guide plates are arranged in the guide cavity, and the plurality of guide plates respectively include an air inlet section, an air outlet section and a transition section, and the transition section is connected between the air inlet section and the air outlet section.

[0010] Preferably, a second arc isolation plate is provided on the side of the support wall away from the arc extinguishing chamber, and a gap is provided between the second arc isolation plate and the arc isolation member, and the gap constitutes an air inlet connected between the arc striking channel and the guide cavity.

[0011] Preferably, the two side plates are respectively provided with supporting walls, each side plate, its supporting wall and the adjacent arc-isolating member form a flow-guiding cavity, and the two flow-guiding cavities are relatively arranged on both sides of the arc-strike channel.

[0012] Preferably, the arc extinguishing chamber includes a plurality of arc extinguishing grids arranged in parallel, the plurality of arc extinguishing grids are respectively provided with notches in the middle of the end surface close to one end of the arc striking chamber, and the arc extinguishing grids are respectively provided with straight portions on both sides of the notches, the notches of the plurality of arc extinguishing grids are respectively arranged corresponding to the arc striking channels, and the two straight portions of the plurality of arc extinguishing grids are respectively arranged corresponding to the two guide cavities.

[0013] Preferably, the width of the notch is equal to the width of the arc striking channel, and the width of the straight portion is equal to the width of the flow guiding cavity.

[0014] Preferably, the shell includes a bottom plate connected between two side plates, and a baffle plate arranged opposite to the bottom plate, the arc extinguishing chamber is arranged between the baffle plate and the bottom plate, the supporting wall includes a first arc isolation plate arranged opposite to the bottom plate, a third arc isolation plate connected to the bottom plate, and a second arc isolation plate connected between the first arc isolation plate and the third arc isolation plate, a gap is provided between the second arc isolation plate and the arc isolation member, and the gap constitutes an air inlet connected between the arc striking channel and the guide cavity.

[0015] Preferably, the third arc isolation plate is arranged at an oblique angle to the bottom plate and the second arc isolation plate respectively, and a magnetic conductive plate is provided on the arc isolation member, and the magnetic conductive plate is provided with a supporting portion extending out of the side surface of the arc isolation member, and the supporting portion is limitedly cooperated with the third arc isolation plate so that the arc isolation member is spaced apart from the side plate.

[0016] Preferably, the second arc isolation plate is provided with an escape portion recessed toward the inner side of the flow guide cavity, the escape portion is used to escape the flexible connection, and the flexible connection is used to connect the moving contact and the wiring terminal.

[0017] Preferably, an arc striking angle is provided in the arc striking chamber, and the arc striking angle includes a connecting part and a mounting part and an arc striking part respectively connected to the connecting part, and the connecting part is provided with a static contact cooperating with the moving contact away from the arc extinguishing chamber, and the mounting part and the arc striking part are respectively arranged on the side of the connecting part close to the arc extinguishing chamber, and a magnetic conductive space is enclosed between the arc striking part, the connecting part and the mounting part, and a magnet is provided in the magnetic conductive space, and the magnet is used to generate a magnetic field in the arc striking chamber to attract the arc.

[0018] Preferably, the air inlet sections of the multiple guide plates are arranged in parallel, and the air inlet sections of the multiple guide plates are the same length, and the air outlet sections of the multiple guide plates are arranged in parallel, and the length of the air outlet sections of the multiple guide plates gradually increases in the direction away from the supporting structure.

[0019] The circuit breaker created by the present invention, by arranging a supporting wall on the side plate of the shell, enclosing a guide cavity arranged in parallel with the arc striking channel between the side plate, the supporting wall and the outer side of the arc isolation member, and connecting the guide cavity with the arc striking channel, not only can the arc and gas generated by the circuit breaker breaking be attracted to the arc extinguishing chamber through the arc striking channel, but also when the gas pressure generated by the circuit breaker breaking is high, the gas will enter the guide cavity driven by the pressure difference, avoiding that all the high-temperature and high-pressure gases generated at the moment of breaking are concentrated in the arc striking channel. After the gas is cooled and assisted in pressure relief by the guide cavity, it enters the arc extinguishing chamber and is extinguished, effectively improving the circuit breaker's ability to withstand the moment of breaking.

[0020] In addition, the side panel is provided with a guide plate for inserting into the guide cavity, and guide channels are formed on both sides of the guide plate. The guide channels are connected between the air inlet and the air outlet of the guide cavity. The guide channels can guide the direction of the airflow, avoid the airflow from concentrating in the guide cavity, and increase the flow speed of the gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the circuit breaker;

[0022] Figure 2 It is a schematic diagram of the structure of the diversion cavity;

[0023] Figure 3 yes Figure 2 A partial enlarged view of

[0024] Figure 4 It is a structural schematic diagram of the arc striking channel;

[0025] Figure 5 It is a schematic diagram of the structure of the air inlet;

[0026] Figure 6 It is a schematic diagram of the cooperation between two arc-isolating parts and magnets;

[0027] In the figure, 2, arc-isolating member; 3, arc-striking channel; 4, side plate; 5, supporting wall; 6, flow-guiding cavity; 7, magnetic plate; 8, supporting structure; 11, shell; 12, arc-extinguishing chamber; 13, arc-striking chamber; 17, terminal; 41, flow-guiding plate; 42, air inlet section; 43, transition section; 44, air outlet section; 51, first arc-isolating plate; 52, second arc-isolating plate; 53, third arc-isolating plate; 54, avoidance part; 60, flow-guiding channel; 61, air inlet; 62, air outlet; 71, supporting part; 81, High platform; 82, high ribs; 83, mounting groove; 84, mounting hole; 111, bottom plate; 112, baffle; 121, arc extinguishing grid; 122, notch; 123, straight portion; 141, operating mechanism; 142, handle; 151, moving contact; 152, arc striking angle; 153, static contact; 154, connecting portion; 155, mounting portion; 156, arc striking portion; 157, magnet; 158, limiting boss; 159, limiting hole; 161, thermal tripping mechanism; 162, magnetic tripping mechanism. DETAILED DESCRIPTION

[0028] The following embodiments are given in conjunction with the accompanying drawings to further illustrate the specific implementation of the circuit breaker created by the present invention. The circuit breaker created by the present invention is not limited to the description of the following embodiments.

[0029] like Figure 1-4 As shown, the circuit breaker of this embodiment includes a shell 11 and an arc extinguishing chamber 12 and an arc striking chamber 13 respectively arranged in the shell 11, the arc striking chamber 13 includes two arc-isolating members 2 arranged opposite to each other, and an arc striking channel 3 is formed between the two arc-isolating members 2, the shell 11 includes two side plates 4, the two side plates 4 are respectively arranged on the sides of the two arc-isolating members 2 away from the arc striking channel 3, at least one of the side plates 4 is provided with a supporting wall 5, and a flow guide cavity 6 is formed between the supporting wall 5, the side plate 4 and the arc-isolating member 2, the flow guide cavity 6 and the arc striking channel 3 are relatively arranged on both sides of the arc-isolating member 2, and the flow guide cavity 6 is provided with an air inlet 61 connected to the arc striking channel 3, and an air outlet 62 connected to the arc extinguishing chamber 12.

[0030] The circuit breaker of this embodiment is provided with a support wall 5 on the side plate 4 of the shell 11, and a guide cavity 6 is formed between the side plate 4, the support wall 5 and the outer side of the arc-isolating member 2 and is arranged in parallel with the arc-striking channel 3, and the guide cavity 6 is connected with the arc-striking channel 3. Not only can the arc and gas generated by the circuit breaker breaking be attracted to the arc extinguishing chamber 12 through the arc-striking channel 3, but also when the gas pressure generated by the circuit breaker breaking is high, the gas will enter the guide cavity 6 driven by the pressure difference, so as to avoid that the high-temperature and high-pressure gas generated at the moment of breaking is all concentrated in the arc-striking channel 3. After the gas is cooled and assisted in pressure relief by the guide cavity 6, it enters the arc extinguishing chamber 12 and is extinguished, thereby effectively improving the circuit breaker's ability to withstand the moment of breaking. It can be understood that the arc is generated at the two poles between the arc isolation member 2, and the arc root will move along the electrode surface. The arc will not enter the guide cavity 6. At the same time, when the air pressure in the arc striking channel 3 is not high, the air will be exhausted normally along the arc striking channel 3. Since the arc striking chamber is provided with a magnet 157, a magnetic conductive plate 7 and other structures, the arc movement is accelerated by the magnetic blowing technology, and the arc is accelerated to enter the arc extinguishing chamber through the driving effect of the electromagnetic field force. Therefore, it will not affect the normal exhaust of the arc striking channel 3. On this basis, the guide cavity 6 can effectively improve the ultimate bearing capacity of the lower circuit breaker.

[0031] like Figure 1 As shown, the arc striking chamber 13 of this embodiment is arranged on the right side of the arc extinguishing chamber 12, an operating mechanism 141 and a handle 142 connected to the operating mechanism 141 are arranged above the arc striking chamber 13, a contact system is arranged above the arc striking chamber 13, the operating mechanism 141 is connected to a moving contact 150 of the contact system, a moving contact 151 is welded on the moving contact 150, a thermal tripping mechanism 161 is arranged on the right side of the operating mechanism 141, the moving contact 151 is connected to the right side terminal 17 through the bimetallic strip of the thermal tripping mechanism 161, and a contact connected to the arc striking angle 152 is arranged above the arc extinguishing chamber 12. A magnetic tripping mechanism 162, the arc striking angle 152 is inserted into the arc striking channel 3, a static contact 153 connected to the arc striking angle 152 is provided in the arc striking channel 3, the static contact 153 is connected to the left terminal 17 through the coil of the magnetic tripping mechanism 162, the operating mechanism 141 is used to drive the moving contact 151 to contact and separate from the static contact 153, and the thermal tripping mechanism 161 and the magnetic tripping mechanism 162 respectively drive the operating mechanism 141 to trip when the overload current and the short-circuit current reach the threshold value, so that the operating mechanism 141 drives the moving contact 151 to separate from the static contact 153.

[0032] like Figure 2-4As shown, the arc striking chamber 13 is correspondingly arranged between the disconnecting position of the moving contact 151 and the arc extinguishing chamber 12, and the two arc isolating members 2 are relatively arranged to form an arc striking channel 3, which is used to lead the arc generated when the moving contact 151 and the static contact 153 are disconnected into the arc extinguishing chamber 12. The static contact 153 is located in the arc striking chamber 13, and the moving contact 151 can swing into the arc striking chamber 13 and contact the static contact 153.

[0033] like Figure 2-4 As shown, the housing 11 includes two side panels 4, only one side panel 4 is shown in the figure, and the other side panel 4 is hidden. The two side panels 4 are relatively arranged on the outside of the two arc-isolating members 2 of the arc-striking chamber 13, and the two side panels 4 are respectively provided with support walls 5. The two arc-isolating members 2 and the corresponding outer side panels 4 and the support walls 5 on the side panels 4 respectively form a guide cavity 6, and the two guide cavities 6 respectively surrounded by the two arc-isolating members 2 are relatively arranged on both sides of the arc-striking channel 3. By respectively arranging the guide cavities 6 on both sides of the arc-striking channel 3, the layout is more reasonable and the gas flow is also convenient. Of course, the guide cavity 6 can also be arranged only on one side and not on the other side, which all belong to the protection scope of the invention. In addition, the housing 11 of the circuit breaker usually includes an upper cover and a base arranged relatively, and the two side panels 4 are respectively a part of the upper cover and a part of the base.

[0034] like Figure 2-3 As shown, a magnetic conductive plate 7 is provided in the flow guide cavity 6, and the magnetic conductive plate 7 is used to generate a magnetic field that attracts the arc to move toward the arc extinguishing chamber 12. Moreover, the magnetic conductive plate 7 is a metal with strong thermal conductivity. The magnetic conductive plate 7 can reduce the temperature of the airflow. After the high-temperature and high-pressure gas at the moment of breaking enters the flow guide cavity 6, it can be quickly cooled by the magnetic conductive plate 7, thereby improving the ability of the flow guide cavity 6 to cool the high-temperature gas and further improving the breaking capacity of the circuit breaker.

[0035] like Figure 2-3 As shown, a support structure 8 is provided between the side plate 4 and the arc isolation member 2, and the support structure 8 is respectively limitedly cooperated with the side plate 4 and the arc isolation member 2, so that the side plate 4 and the arc isolation member 2 are arranged at intervals, and the magnetic conductive plate 7 is provided with an avoidance groove for avoiding the support structure 8, thereby ensuring sufficient space to enclose the guide cavity 6.

[0036] like Figure 2-3 6, the support structure 8 of this embodiment includes a high platform 81 arranged on the side plate 4, and a high rib 82 arranged on the arc isolation member 2, a mounting groove 83 is arranged in the middle of the high rib 82, and a mounting hole 84 is arranged at the bottom of the mounting groove 83. The high platform 81 and the high rib 82 arranged separately form the support structure 8, which is not only convenient for assembly, but also the high rib 82 is arranged on the arc isolation member 2, which can also increase the creepage distance and improve safety. Of course, the support structure 8 can also be provided with only one of the high platform 81 or the high rib 82, and the height is increased accordingly, which belongs to the protection scope of the invention.

[0037] like Figure 2-3 As shown, a guide plate 41 is provided in the guide cavity 6, which is used to divide the guide cavity 6 to form a plurality of guide channels 60, and the guide channels 60 are connected between the air inlet 61 and the air outlet 62 of the guide cavity 6. The guide channels 60 can guide the direction of the airflow, avoid the airflow from being concentrated in the guide cavity 6, and increase the flow speed of the gas. In this embodiment, the guide plate 41 is arranged on the side plate 4, inserted into the guide cavity 6, and the guide channels 60 are formed on both sides of the guide plate 41.

[0038] Specifically, the guide cavity 6 is provided with a plurality of guide channels 60. In this embodiment, three guide plates 41 are provided, forming a total of four guide channels 60. Of course, at least one or other number of guide plates 41 may also be provided, and all of them belong to the protection scope of the invention. The middle portion of the guide plate 41 bulges toward the side away from the support structure 8 to form a transition section 43 in the shape of a curved surface. The three guide plates 41 respectively include an air inlet section 42, an air outlet section 44 and a transition section 43. The transition section 43 is connected between the air inlet section 42 and the air outlet section 44. The air inlet sections 42 of the plurality of guide plates 41 are arranged in parallel, and the air inlet sections 42 of the plurality of guide plates 41 are of the same length. The air outlet sections 44 of the plurality of guide plates 41 are arranged in parallel, and the length of the air outlet sections 44 of the plurality of guide plates 41 gradually increases in the direction away from the support structure 8.

[0039] By providing a transition section 43 in a curved shape on the guide plate 41, the airflow can flow more smoothly and achieve a better guiding effect. Of course, even if only one guide plate 41 is provided, the transition section 43 can also be provided on the guide plate 41, which all belongs to the protection scope of the invention.

[0040] like Figure 2-3 As shown, the shell 11 includes a bottom plate 111 connected between two side plates 4, and a baffle 112 arranged opposite to the bottom plate 111, the arc extinguishing chamber 12 is arranged between the baffle 112 and the bottom plate 111, the support wall 5 is roughly U-shaped, and the support wall 5 includes a first arc isolation plate 51 arranged opposite to the bottom plate 111, and a third arc isolation plate 53 connected to the bottom plate 111, and a second arc isolation plate 52 is provided on the side of the support wall 5 away from the arc extinguishing chamber 12, the second arc isolation plate 52 is connected between the first arc isolation plate 51 and the third arc isolation plate 53, and a gap is provided between the second arc isolation plate 52 and the arc isolation member 2, and the gap constitutes an air inlet 61 connected between the arc striking channel 3 and the guide cavity 6.

[0041] like Figure 2-36, the third arc isolation plate 53 is tilted, and the third arc isolation plate 53 is respectively arranged at an oblique angle with the bottom plate 111 and the second arc isolation plate 52, and the magnetic conductive plate 7 is provided with a support portion 71 extending outside the side of the arc isolation member 2, and the support portion 71 is limitedly matched with the third arc isolation plate 53, so that the arc isolation member 2 is spaced from the side plate 4. The tilted third arc isolation plate 53 can not only play a role in directly or indirectly limiting the arc isolation member 2, but also play a role in guiding the flow direction of the airflow.

[0042] like Figure 2-3 As shown, the second arc isolation plate 52 is provided with an escape portion 54 recessed toward the inner side of the flow guide cavity 6 , and the escape portion 54 is used to escape a flexible connection (not shown in the figure), and the flexible connection is used to connect the moving contact 150 and the terminal 17 .

[0043] like Figure 2-4 As shown, the arc extinguishing chamber 12 includes a plurality of arc extinguishing grids 121 arranged in parallel, each of the plurality of arc extinguishing grids 121 is provided with a notch 122 in the middle of the end surface close to one end of the arc striking chamber 13, and each of the arc extinguishing grids 121 is provided with a straight portion 123 on both sides of the notch 122, the notches 122 of the plurality of arc extinguishing grids 121 are respectively arranged corresponding to the arc striking channels 3, and the two straight portions 123 of the plurality of arc extinguishing grids 121 are respectively arranged corresponding to the two flow guiding cavities 6. Preferably, the width of the notch 122 is equal to the width of the arc striking channel 3, and the width of the straight portion 123 is equal to the width of the flow guiding cavity 6, Figure 2-3 It shows that the straight portion 123 on one side corresponds to the flow guiding cavity 6 and has the same width. Figure 4 is a cross-sectional view, Figure 4 Cut off Figure 2-3 The straight portion 123 and the flow guiding cavity 6 are shown in the figure, while the straight portion 123 on the other side is blocked by the arc isolation member 2, and only the notch 122 and the arc striking channel 3 are shown to be arranged correspondingly.

[0044] like Figure 6As shown, the arc striking chamber 13 is provided with an arc striking angle 152, and the arc striking angle 152 includes a connecting portion 154 and a mounting portion 155 and an arc striking portion 156 respectively connected to the connecting portion 154, and the connecting portion 154 is provided with a static contact 153 cooperating with the moving contact 151 away from the arc extinguishing chamber 12, and the mounting portion 155 and the arc striking portion 156 are respectively arranged on the side of the connecting portion 154 close to the arc extinguishing chamber 12, and the arc striking portion 156, the connecting portion 154 and the mounting portion 155 are respectively arranged on the side of the connecting portion 154 close to the arc extinguishing chamber 12. A magnetic conductive space is enclosed between the parts 155, in which a magnet 157 is provided. The magnet 157 is used to generate a magnetic field for attracting the arc in the arc striking chamber 13, and the two arc-isolating members 2 are respectively provided with limiting bosses 158 for being inserted into the magnetic conductive space, and the limiting bosses 158 are respectively provided with limiting holes 159 for being sleeved on the magnet 157, and the limiting holes 159 of the two limiting bosses 158 constitute a limiting cavity for accommodating the magnet 157.

[0045] The magnet 157 is a permanent magnet or a magnetic conductor. The permanent magnet can be used for direct current. The magnetic field generated by direct current is fixed. The arc is pushed toward the arc extinguishing chamber through the directional magnetic field enhancement of the permanent magnet. The magnetic conductor can be used for alternating current. The magnetic conductor passively generates a magnetic field under the action of the electric field, and the magnetic field is independent of the direction of the current, and the arc is always pushed toward the arc extinguishing chamber.

[0046] It should be noted that in the description of the invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship usually placed when in use, which is only for the convenience of description, and does not indicate that the device or element referred to must have a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating relative importance.

[0047] The above content is a further detailed description of the invention in combination with specific preferred implementation methods, and it cannot be determined that the specific implementation of the invention is limited to these descriptions. For ordinary technicians in the technical field to which the invention belongs, several simple deductions or substitutions can be made without departing from the concept of the invention, which should be regarded as falling within the scope of protection of the invention.

Claims

1. A circuit breaker, comprising a housing (11) and an arc extinguishing chamber (12) and an arc striking chamber (13) respectively arranged in the housing (11), wherein the arc striking chamber (13) comprises two arc isolating members (2) arranged opposite to each other, and an arc striking channel (3) is formed between the two arc isolating members (2), characterized in that: The shell (11) comprises two side plates (4), the two side plates (4) are respectively arranged on the sides of the two arc-isolating members (2) away from the arc-striking channel (3), at least one of the side plates (4) is provided with a support wall (5), a flow guide cavity (6) is formed between the support wall (5), the side plate (4) and the arc-isolating member (2), the flow guide cavity (6) and the arc-striking channel (3) are arranged on two sides of the arc-isolating member (2) opposite to each other, and the flow guide cavity (6) is provided with an air inlet (61) connected to the arc-striking channel (3), and an air outlet (62) connected to the arc-extinguishing chamber (12).

2. The circuit breaker according to claim 1, characterized in that: A magnetic conductive plate (7) is provided in the flow guiding cavity (6), and the magnetic conductive plate (7) is used to generate a magnetic field that attracts the electric arc to move toward the arc extinguishing chamber (12).

3. The circuit breaker according to claim 1, characterized in that: A guide plate (41) is provided in the guide cavity (6) for dividing the guide cavity (6) to form a plurality of guide channels (60), wherein the guide channels (60) are connected between the air inlet (61) and the air outlet (62) of the guide cavity (6).

4. The circuit breaker according to claim 3, characterized in that: A supporting structure (8) is provided between the side plate (4) and the arc-isolating member (2), so that the side plate (4) and the arc-isolating member (2) are arranged at intervals.

5. The circuit breaker according to claim 4, characterized in that: The support structure (8) is located at an end corner of the arc-isolating member (2) adjacent to the static contact (153) and the arc-extinguishing chamber (12); the middle portion of the guide plate (41) protrudes toward the side away from the support structure (8) to form a transition section (43) with a curved surface shape; a plurality of guide plates (41) are arranged in the guide cavity (6); the plurality of guide plates (41) respectively include an air inlet section (42), an air outlet section (44) and a transition section (43); the transition section (43) is connected between the air inlet section (42) and the air outlet section (44).

6. The circuit breaker according to claim 1, characterized in that: A second arc isolation plate (52) is provided on the side of the support wall (5) away from the arc extinguishing chamber (12), and a gap is provided between the second arc isolation plate (52) and the arc isolation member (2), the gap forming an air inlet (61) connected between the arc striking channel (3) and the flow guiding cavity (6).

7. The circuit breaker according to claim 1, characterized in that: The two side plates (4) are respectively provided with supporting walls (5), and each side plate (4) and its supporting wall (5) and the adjacent arc-isolating member (2) form a flow-guiding cavity (6), and the two flow-guiding cavities (6) are arranged opposite to each other on both sides of the arc-strike channel (3).

8. The circuit breaker according to claim 7, characterized in that: The arc extinguishing chamber (12) comprises a plurality of arc extinguishing grids (121) arranged in parallel, each of the plurality of arc extinguishing grids (121) being provided with a notch (122) at the middle of an end surface close to an arc striking chamber (13), and each of the arc extinguishing grids (121) being provided with a straight portion (123) on both sides of the notch (122), the notches (122) of the plurality of arc extinguishing grids (121) being respectively arranged corresponding to the arc striking channels (3), and the two straight portions (123) of the plurality of arc extinguishing grids (121) being respectively arranged corresponding to the two flow guiding cavities (6).

9. The circuit breaker according to claim 8, characterized in that: The width of the notch (122) is equal to the width of the arc striking channel (3), and the width of the straight portion (123) is equal to the width of the flow guiding cavity (6).

10. The circuit breaker according to claim 7, characterized in that: The housing (11) comprises a bottom plate (111) connected between two side plates (4), and a baffle (112) arranged opposite to the bottom plate (111); the arc extinguishing chamber (12) is arranged between the baffle (112) and the bottom plate (111); the supporting wall (5) comprises a first arc isolation plate (51) arranged opposite to the bottom plate (111), a third arc isolation plate (53) connected to the bottom plate (111), and a second arc isolation plate (52) connected between the first arc isolation plate (51) and the third arc isolation plate (53); a gap is provided between the second arc isolation plate (52) and the arc isolation member (2), and the gap constitutes an air inlet (61) connected between the arc striking channel (3) and the flow guide cavity (6).

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