A temperature regulating assembly for a molded case circuit breaker and a method of regulating temperature

Abstract

The application provides a temperature rise adjusting assembly of a universal circuit breaker without affecting the protection level, and the base of the universal circuit breaker has a containing cavity, and the bottom end of the containing cavity is provided with a through hole; the temperature rise adjusting assembly comprises: a heat dissipation assembly, which comprises: a heat dissipation seat having a cavity with an opening facing upwards, a plurality of air vents are formed in the bottom of the cavity, and the air vents are communicated with the through hole to form a flow channel for the outside air to flow into the containing cavity; a cover plate arranged in the cavity and capable of covering the opening; and an elastic unit arranged between the cover plate and the heat dissipation seat and maintaining an opening and closing angle between the cover plate and the heat dissipation seat through the tension of the elastic unit; and the heat bimetallic element is fixedly connected to the movable contact support at one end and downwardly extended to form a bent portion at the other end. Through the disclosure of the application, the heat bimetallic element is matched with the heat dissipation assembly to adapt to three states of the circuit breaker, the protection level of the circuit breaker is not affected, the temperature rise inside the circuit breaker is adjusted, the structure is simple, and the installation is convenient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of universal circuit breaker, more particularly to a universal circuit breaker temperature rise adjusting assembly without affecting the protection level and an adjusting method. BACKGROUND

[0002] The universal circuit breaker is an important control element in the power system, mainly playing a protection role of overload and short circuit. In order to reliably play the above protection role, the universal circuit breaker has many parameter indexes, and the temperature rise is an important index. However, since the circuit breaker has N poles, and each pole is an independent chamber composed of a base and a bottom plate, only the inlet end has an air flow hole, the outlet end is closed, and the volume and other factors of the universal circuit breaker affect the temperature rise of the universal circuit breaker to remain in the standard range, which has always been a design difficulty.

[0003] The temperature rise refers to the phenomenon that the surface temperature and internal temperature of the product gradually rise due to the heat generated by the conductive part itself, and the heat dissipation and environmental temperature rise. If the temperature rise is high, the product will work in a high temperature for a long time, accelerate the aging of the internal control board and the line connector, accelerate the wear of the mechanical part and increase the failure rate, and reduce the service life of the whole machine. Therefore, it is necessary to control the temperature rise of the universal circuit breaker in the possible range, and to accelerate the exhaust of hot air in the circuit breaker chamber under the condition of constant volume, that is, to need air convection, and to need to increase some air flow holes on the end bottom wall of the circuit breaker. However, this will damage the protection level of the circuit breaker, affect the safe use of the circuit breaker, and affect the performance, service life and other performances of the circuit breaker. Therefore, a component is needed to control the temperature rise of the circuit breaker without affecting the protection level of the circuit breaker, so as to ensure the normal work of the product and improve the performance and mechanical service life of the product. SUMMARY

[0004] The present application discloses a universal circuit breaker temperature rise adjusting assembly without affecting the protection level and an adjusting method, which solves the problem that the temperature rise adjusting structure in the prior art reduces the protection level of the circuit breaker, and has a complex structure and is difficult to install. The temperature rise adjusting assembly in the present application can adapt to three states of the circuit breaker, adjust the temperature rise in the circuit breaker without affecting the protection level of the circuit breaker, has a simple structure, and is convenient to install and disassemble.

[0005] To achieve the above object, the present application provides a universal circuit breaker temperature rise adjusting assembly without affecting the protection level, wherein the base of the universal circuit breaker has a receiving cavity, and a through hole is formed in the bottom end of the receiving cavity and leads to the outside of the base.

[0006] The temperature rise adjusting assembly comprises:

[0007] A heat dissipation assembly arranged at the bottom of the accommodating cavity comprises:

[0008] A heat dissipation seat has a cavity with an opening upward, the bottom of the cavity is provided with a plurality of air holes, and the cavity is connected with the through hole through the air holes to form a flow channel for the outside air to flow into the accommodating cavity;

[0009] A cover plate is arranged in the cavity and can cover the opening, the cover plate and the heat dissipation seat are rotationally connected, and the cover plate and the heat dissipation seat form an opening and closing angle through rotation to change the opening and closing state of the flow channel;

[0010] An elastic unit is arranged between the cover plate and the heat dissipation seat and maintains the opening and closing angle between the cover plate and the heat dissipation seat through its own tension;

[0011] An abutting portion is fixedly arranged at the top end of the cover plate;

[0012] Further comprising a thermal bimetallic element horizontally arranged at the bottom of the movable contact support and fixedly connected with one end of the movable contact support and extended downward to form a bent portion, the bent portion can abut against the abutting portion during installation and overcome the self-tension of the elastic unit to make the cover plate and the heat dissipation seat in a closed state;

[0013] The thermal bimetallic element is bent and deformed in a heated state to make the bent portion disengage from the abutting portion.

[0014] As a further improvement of the application, the heat dissipation seat has a double-layer structure, and the lower layer can be inserted into the through hole, the cavity comprises a cylindrical upper cavity and a lower cavity, the cross-sectional dimension of the upper cavity is larger than that of the lower cavity, an outer step surface is formed between the outer wall of the upper cavity and the outer wall of the lower cavity, and an inner step surface is formed between the inner wall of the upper cavity and the inner wall of the lower cavity;

[0015] The outer step surface supports the heat dissipation seat on the bottom wall of the accommodating cavity, and the inner step surface supports the cover plate.

[0016] As a further improvement of the application, a rotating shaft perpendicular to the rotating direction of the cover plate is arranged on the side of the cover plate close to the thermal bimetallic element, and the two ends of the rotating shaft are rotationally connected with the inner wall of the heat dissipation seat.

[0017] As a further improvement of the application, the abutting portion is arranged on the side of the cover plate close to the bent portion and has a triangular structure, and the top end of the triangle has a round pie-shaped abutting end.

[0018] As a further improvement of the application, the elastic unit comprises a tension spring, a compression spring and a torsion spring.

[0019] As a further improvement of the application, the thermal bimetallic element is in L-shaped structure and is rigidly connected to the movable contact support by welding or riveting.

[0020] As a further improvement of the application, the heat dissipation base is provided with a limiting structure for limiting the rotation angle of the cover plate on the side close to the rotation center, and the cover plate can abut against the limiting structure to limit the opening angle.

[0021] As a further improvement of the application, the cover plate is in disc-shaped structure, and the side close to the rotation center is formed with an arc surface gradually shrinking inward from the top end to the bottom end of the cover plate, and the limiting structure is a limiting surface which is a slope surface and cooperates with the arc surface.

[0022] As a further improvement of the application, the elastic unit is a tension spring, one end of which is installed in the air hole and the other end is installed on the cover plate.

[0023] The application further discloses a regulating method of the temperature rise regulating assembly of the universal circuit breaker without affecting the protection level, which comprises the following steps:

[0024] S1, when the circuit breaker is not powered, the bending part abuts against the rear end of the abutting part and overcomes the tension of the elastic unit, so that the cover plate and the heat dissipation base are in a closed state;

[0025] S2, when the circuit breaker is powered, the horizontal section of the thermal bimetallic element is bent and deformed, the bending part is separated from the abutting part and a gap exists, the cover plate is rotated clockwise under the action of the tension of the elastic unit, so that the opening of the heat dissipation base is opened, the cold air outside the circuit breaker is continuously supplemented into the circuit breaker through the flow channel, and air convection is formed;

[0026] S3, when the circuit breaker occurs short-circuit fault, the cover plate is rotated counterclockwise under the impact of the high-temperature and high-pressure gas generated when the circuit breaker is broken, so as to overcome the tension of the elastic unit, so that the opening angle between the cover plate and the heat dissipation base is 0°, and the gas in the circuit breaker is hindered from flowing out to the outside through the flow channel;

[0027] S4, after the circuit breaker is broken, the air pressure in the circuit breaker returns to the normal atmospheric pressure value, the circuit breaker is cooled, the thermal bimetallic element returns to the initial state, and the cover plate and the heat dissipation base return to the state of step S1.

[0028] Compared with the prior art, the application has the following beneficial effects:

[0029] (1) A universal circuit breaker temperature rise adjusting assembly that does not affect the protection level, the modularly arranged temperature rise adjusting assembly cooperates with the heat dissipation assembly through the thermal bimetallic element and is adapted to three states of the circuit breaker, while not affecting the protection level of the circuit breaker, the temperature rise inside the circuit breaker is adjusted; the heat dissipation assembly is composed of a heat dissipation seat, a cover plate, an elastic unit and an abutting portion, arranged in a containing cavity, the heat dissipation seat is partially inserted into a through hole opened at the bottom of the containing cavity, cooperation installation is realized, simple operation, high installation and disassembly efficiency;

[0030] (2) A plurality of air holes are opened at the bottom of the heat dissipation seat, during installation, the thermal bimetallic element abuts against the rear end of the abutting portion, overcoming the tension of the elastic unit, to form protection for the first state of the circuit breaker, that is, when the circuit breaker is not powered, the cover plate closes the opening of the heat dissipation seat, effectively solving the problem of reducing the protection level of the circuit breaker by punching holes in the base of the existing technology; by using the thermal deformation characteristics of the thermal bimetallic element, when the circuit breaker is in the second state, that is, when the circuit breaker is powered on, the thermal bimetallic element gradually separates from the rear end of the abutting portion due to thermal deformation, the cover plate rotates under the tension of the elastic unit, forming an opening and closing angle between the heat dissipation seat, using hot air to pass through the inlet end to the outside of the chamber of the circuit breaker, while the cold air outside the circuit breaker forms an air flow channel through the heat dissipation seat to continuously supplement the chamber of the circuit breaker, realizing air convection, effectively improving the temperature rise inside the circuit breaker;

[0031] (3) The bottom of the heat dissipation seat is inserted into the through hole opened at the bottom of the containing cavity, realizing installation and fixation, by opening a plurality of air holes at the bottom of the heat dissipation seat and setting an opening at the top of the heat dissipation seat, a heat dissipation channel is formed in the base, the opening of the heat dissipation seat is closed by the cover plate, on the one hand, the position of the air inlet and the structure of the heat dissipation channel are changed, so that the air inlet efficiency can be improved under the influence of the air pressure and temperature inside and outside the circuit breaker, and the pressure can be accumulated, at the same time, the chamber formed inside the heat dissipation seat is still connected with the outside through the air holes, and it still has certain cooling property, which can conduct additional heat conduction cooling to the inside of the circuit breaker when the circuit breaker breaks down, that is, the cover plate is closed under the pressure of the high-temperature and high-pressure gas generated by the segmentation of the circuit breaker, on the other hand, the height of the cover plate can improve the closing speed of the cover plate under the pressure of the high-temperature and high-pressure gas, avoiding the high-temperature and high-pressure gas from being discharged from the air holes of the heat dissipation seat to the outside of the chamber of the circuit breaker, thereby not affecting the breaking performance of the circuit breaker and improving the protection level. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The position relationship between the thermal bimetallic element and the heat dissipation assembly of the universal circuit breaker temperature rise adjusting assembly of the present application when the circuit breaker is not powered;

[0033] Figure 2 The universal circuit breaker temperature rise adjusting assembly of the present application does not affect the protection level, when the circuit breaker is powered, the internal temperature rises, the state of the heat dissipation assembly and the thermal bimetallic element changes;

[0034] Figure 3 The universal circuit breaker temperature rise adjusting assembly of the present application does not affect the protection level, when the circuit breaker is powered, the internal temperature rises, the state of the heat dissipation assembly and the thermal bimetallic element changes;

[0035] Figure 4 The universal circuit breaker temperature rise adjusting assembly of the present application does not affect the protection level, when the circuit breaker is powered, the internal temperature rises, the state of the heat dissipation assembly and the thermal bimetallic element changes;

[0036] Figure 5 The front view of Figure 4 ;

[0037] Figure 6 The cross-sectional view along the horizontal transverse direction, wherein S represents the direction of the external air flowing into the flow channel; Figure 5

[0038] The universal circuit breaker temperature rise adjusting assembly of the present application does not affect the protection level, when the circuit breaker is powered, the internal temperature rises, the state of the heat dissipation assembly and the thermal bimetallic element changes; Figure 7

[0039] The universal circuit breaker temperature rise adjusting assembly of the present application does not affect the protection level, when the circuit breaker is powered, the internal temperature rises, the state of the heat dissipation assembly and the thermal bimetallic element changes. Figure 8 In the figure: 10, base; 11, heat dissipation assembly; 12, thermal bimetallic element; 13, moving contact support; 100, accommodating cavity; 111, heat dissipation seat; 112, cover plate; 113, elastic unit; 114, abutting portion; 115, rotating shaft; 121, bent portion; 101, rectangular groove; 1110, cavity; 1111, outer step surface; 1112, inner step surface.

[0040] DETAILED DESCRIPTION

[0041] The present application will be described in detail below in conjunction with the embodiments shown in the drawings, but it should be noted that these embodiments are not a limitation on the present application, and equivalent transformations or substitutions of the function, method, or structure made by those skilled in the art based on these embodiments are within the scope of protection of the present application.

[0042] ​For the purpose of facilitating the understanding of the present application, a more complete description of the present application will be provided with reference to the accompanying drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0043] Please refer to Figures 1 to 8 A specific embodiment of the temperature rise adjusting assembly of the universal circuit breaker without affecting the protection level is shown.

[0044] A temperature rise adjusting assembly of the universal circuit breaker without affecting the protection level, the universal circuit breaker comprising: a base 10, the bottom of which is formed with a receiving cavity 100, the bottom end of which is provided with a through hole; a movable contact support 13 installed in the base 10; the base 10 and the movable contact support 13 are industry known structures, which are not described here.

[0045] Please refer to Figures 1-4 As shown, the temperature rise adjusting assembly further comprises: a heat dissipation assembly 11 and a thermal bimetallic element 12, the thermal bimetallic element 12 having a deformation characteristic and being arranged in an L-shaped structure, horizontally attached to the bottom of the movable contact support 13, and fixedly connected to the movable contact support 13 at one end and extended downward to form a bent portion 121 at the other end; the end of the horizontal section is rigidly connected to the movable contact support 13 by welding, riveting or the like; in the initial state, the horizontal section of the thermal bimetallic element 12 is tightly attached to the wall of the movable contact support 13; when the circuit breaker is powered on, the horizontal section of the thermal bimetallic element 12 is heated and deformed in the direction of the outlet end.

[0046] Please refer to Figures 4-6 As shown, the heat dissipation assembly 11 is arranged in the receiving cavity 100 and partially inserted into the through hole, and the bottom end of the heat dissipation assembly 11 is located in the through hole or flush with the bottom end of the base 10; the heat dissipation assembly 11 specifically comprises: a heat dissipation seat 111, a cover plate 112, an elastic unit 113 and an abutting portion 114, the heat dissipation seat 111 having a cavity 1110 with an opening facing upward, the bottom of the cavity 1110 being provided with a plurality of air holes; the cover plate 112 is arranged in the cavity 1110 and covers the opening, and a rotating connection is formed between the side of the cover plate 112 close to the bent portion 121 and the heat dissipation seat 111; the elastic unit 113 is arranged between the heat dissipation seat 111 and the cover plate 112 and has a tension, and in the initial state, the cover plate 112 and the heat dissipation seat 111 have an opening and closing angle; the abutting portion 114 is fixedly arranged at the top end of the cover plate 112 and close to the side of the cover plate 112 close to the bent portion 121; the bent portion 121 can abut against the abutting portion 114 during installation and overcome the tension of the elastic unit 113, so that the cover plate 112 and the heat dissipation seat 111 are in a closed state; the thermal bimetallic element 12 is deformed under the condition of being heated by power, so that the bent portion 121 can be separated from the abutting portion 114.

[0047] As shown Figure 7 in Figure 1, the heat dissipation base 111 has a double-layer structure, and the chamber 1110 includes a cylindrical upper chamber and a lower chamber. The cross-sectional dimension of the upper chamber is larger than that of the lower chamber. An outer step surface 1111 is formed between the outer walls of the upper chamber and the lower chamber, and an inner step surface 1112 is formed between the inner walls of the upper chamber and the lower chamber. The lower chamber of the heat dissipation base 111 is movably inserted into the through hole and supported on the bottom wall of the accommodating chamber 100 through the outer step surface 1111, and the inner step surface 1112 is used for the cover plate 112 to be limited and supported.

[0048] As shown Figure 8 in Figure 2, a rotating mechanism is arranged between the cover plate 112 and the heat dissipation base 111, so that the cover plate 112 can rotate clockwise relative to the heat dissipation base 111. A rectangular groove 101 is formed in the upper chamber of the heat dissipation base 111 for placing the rotating mechanism. The depth of the rotating groove extends to the inner step surface 1112. The rotating mechanism is a rotating shaft 115. The rotating shaft 115 is arranged above the cover plate 112 and deviates from the center of the cover plate 112, and penetrates along the thickness direction of the abutting portion 114, and both ends are rotatably connected to the inner wall of the heat dissipation base 111 respectively. The abutting portion 114 is arranged on the cover plate 112 and on the side close to the bending portion 121, and has a triangular structure, and the top of the triangle forms a disc-shaped abutting end.

[0049] Specifically, a limiting structure for limiting the rotation angle of the cover plate 112 is provided on one side of the heat dissipation base 111 facing the rotation direction of the cover plate 112. The upper surface of the cover plate 112 can abut against the limiting structure, so as to limit the size of the opening and closing angle.

[0050] It should be understood that the limiting structure can be a limiting portion or a limiting surface formed in this solution. The cover plate 112 has a disc-shaped structure, and one side close to the rotation center has an arc surface that is movably matched with the heat dissipation base 111. The limiting surface is an inclined surface with a certain slope designed on the inner side of the heat dissipation base 111 relative to the arc surface of the cover plate 112. Through the arrangement of the limiting structure, the opening and closing angle can be within 45°.

[0051] In this solution, the return spring is a tension spring, but the present invention is not limited to the tension spring, and other elastic structures can also be used, including compression springs and torsion springs. The abutting portion 114 has a triangular convex block structure, and the upper end of the triangular convex block structure is provided in a disc shape.

[0052] 参 Figure 4 与 Figure 7As shown in the figure, during installation, the rotating shaft 115 on the cover plate 112 is installed into the rectangular groove 101 of the heat dissipation base 111, and one end of the tension spring is installed at the installation point of the cover plate 112, while the other end is installed in the ventilation hole at the bottom end of the heat dissipation base 111. At this time, the cover plate 112 rotates clockwise along the rotation center of the rotating shaft 115 under the action of the tension spring until it stops at the limiting surface. After installation, in the initial state, a certain angle is formed between the cover plate 112 and the heat dissipation base 111, and it is in an open state. The moving contact of the existing structure is installed on the moving contact support 13 welded with the thermal bimetallic element 12, and the overall structure is installed in the base 10.

[0053] The present invention also discloses an adjustment method for the temperature rise adjustment component of the universal circuit breaker that does not affect the protection level.

[0054] Refer Figure 1 As shown in the figure, when the circuit breaker is not powered on, the horizontal section of the thermal bimetallic element 12 closely adheres to the outer wall of the moving contact support 13, while the bent portion away from the outer wall 121 presses against the rear end of the disc-shaped part of the triangular structure, overcoming the spring tension of the elastic unit 113, so that the cover plate​​​​​​​​​As shown, when the short-circuit fault occurs in the circuit breaker, high-temperature and high-pressure gas is generated in the circuit breaker along with the breaking of the contact, the cover plate 112 on the heat dissipation assembly 11 is rotated counterclockwise against the spring force under the impact of the internal high-temperature and high-pressure gas, and the cover plate 112 is rotated until the stepped surface of the inner wall of the heat dissipation seat 111, so as to close the air vent hole at the bottom of the heat dissipation seat 111, so that the high-temperature and high-pressure gas generated during breaking will not leak from the outlet end of the circuit breaker, thereby not affecting the breaking performance of the circuit breaker. After the breaking is completed, the high-temperature and high-pressure gas is discharged through the inlet end, and the internal pressure value of the circuit breaker returns to normal. After the breaking is completed, when the circuit breaker cools down, the thermal bimetallic element 12 also returns to the initial state, at this time the cover plate 112 is also pushed by the thermal bimetallic element 12 to overcome the spring force to reach the closed position.

[0057] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.

Claims

1. A universal circuit breaker temperature rise regulating component that does not affect the protection level, wherein the base of the universal circuit breaker has a receiving cavity, and the bottom end of the receiving cavity has a through hole leading to the outside of the base; Its features are, The temperature rise regulation component includes: A heat dissipation assembly, disposed at the bottom of the receiving cavity, includes: The heat sink has an upward-facing chamber, and the bottom of the chamber has several vent holes, which are connected to the through holes to form a flow channel for outside air to flow into the cavity. A cover plate is arranged in the cavity and can cover the opening. The cover plate is rotatably connected to the heat sink. The cover plate and the heat sink form an opening angle by rotating to change the opening and closing state of the flow channel. An elastic unit is arranged between the cover plate and the heat sink, and maintains the opening and closing angle between the cover plate and the heat sink through its own tension; The abutting part is fixed to the top of the cover plate; It also includes a thermal bimetallic element, which is horizontally attached to the bottom of the moving contact bracket, with one end fixedly connected to the moving contact bracket and the other end extending downward to form a bent portion. The bent portion can abut against the abutment portion during installation and overcome the tension of the elastic unit itself, so that the cover plate and the heat sink are in a closed state. The thermal bimetallic element bends and deforms when heated by electricity, allowing the bent portion to detach from the abutting portion.

2. The universal circuit breaker temperature rise regulating component that does not affect the protection level according to claim 1, characterized in that, The heat sink has a double-layer structure, and the lower layer can be inserted into the through hole. The chamber includes a cylindrical upper chamber and a lower chamber. The cross-sectional dimension of the upper chamber is larger than that of the lower chamber. An outer stepped surface is formed between the outer wall of the upper chamber and the outer wall of the lower chamber, and an inner stepped surface is formed between the inner wall of the upper chamber and the inner wall of the lower chamber. The outer stepped surface is used to support the heat sink on the bottom wall of the receiving cavity, and the inner stepped surface is used to limit and support the cover plate.

3. The universal circuit breaker temperature rise regulating component that does not affect the protection level according to claim 1, characterized in that, A rotating shaft perpendicular to the rotation direction of the cover plate is arranged on the side of the cover plate near the thermal bimetallic element, and the two ends of the rotating shaft are respectively rotatably connected to the inner wall of the heat sink.

4. The universal circuit breaker temperature rise regulating component that does not affect the protection level according to claim 1, characterized in that, The abutting part is arranged on the cover plate and on one side near the bending part, and has a triangular structure, with a disc-shaped abutting end formed at the apex of the triangle.

5. The universal circuit breaker temperature rise regulating component that does not affect the protection level according to claim 1, wherein the elastic unit is: a tension spring, a compression spring, or a torsion spring.

6. The universal circuit breaker temperature rise regulating component that does not affect the protection level according to claim 1, characterized in that, The bimetallic thermal element has an L-shaped structure and is rigidly connected to the moving contact bracket by welding or riveting.

7. A universal circuit breaker temperature rise regulating component that does not affect the protection level according to claim 1, characterized in that, The heat sink has a limiting structure on the side near the rotation center to limit the rotation angle of the cover plate. The cover plate can abut against the limiting structure, thereby limiting the size of the opening and closing angle.

8. A universal circuit breaker temperature rise regulating component that does not affect the protection level according to claim 7, characterized in that, The cover plate has a disc-shaped structure, and an arc-shaped surface that gradually tapers inward from the top to the bottom of the cover plate on the side near the rotation center. The limiting structure is a limiting surface, which is an inclined surface that cooperates with the arc-shaped surface.

9. A universal circuit breaker temperature rise regulating component that does not affect the protection level according to claim 5, characterized in that, The elastic unit is a tension spring, with one end of the tension spring installed inside the vent and the other end installed on the cover plate.

10. A method for adjusting the temperature rise regulating component of a universal circuit breaker without affecting the protection level, based on claim 1, characterized in that, Includes the following steps: S1, When the circuit breaker is not energized, the bent part abuts against the rear end of the abutting part and overcomes the tension of the elastic unit, so that the cover plate and the heat sink are in a closed state; S2, When the circuit breaker is energized, the horizontal section of the thermal bimetallic element bends and deforms, the bent part separates from the abutting part and there is a certain gap, the cover plate rotates clockwise under the tension of the elastic unit, so that the opening of the heat sink is opened, and the cold air outside the circuit breaker is continuously replenished into the circuit breaker through the circulation channel, forming air convection. S3, when a short circuit fault occurs in the circuit breaker, the cover plate, under the impact of the high temperature and high pressure gas generated when the circuit breaker is disconnected, overcomes the tension of the elastic unit and rotates counterclockwise, so that the opening angle between the cover plate and the heat sink is 0°, which prevents the gas inside the circuit breaker from flowing out to the outside through the flow channel. S4. After the circuit breaker disconnects, the air pressure inside the circuit breaker returns to the normal atmospheric pressure value, the circuit breaker cools down, the hot bimetallic element returns to its initial state, and the cover plate and the heat sink return to the state of step S1.

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