A circuit breaker short circuit protection mechanism and adjustment method thereof

Abstract

The present application relates to the technical field of circuit breakers, specifically to a circuit breaker short-circuit protection mechanism and an adjustment method thereof, including a circuit breaker mechanism installed inside an insulating housing, the circuit breaker mechanism including an armature located inside a coil, a conductive plate provided at the lower end of the coil, a contact provided at the lower end of the conductive plate, and a safety mechanism provided inside the insulating housing and close to the coil. The present application sets a safety mechanism, sets a drive assembly and a connecting rod assembly on the outside of the coil, sets a circuit current threshold and a temperature threshold through a processor, and uses a connecting rod assembly to disconnect the contact from the conductive plate. When the circuit current of the electrical appliance is overloaded and the magnetic field force of the coil is difficult to push the armature, the internal circuit of the circuit breaker can be disconnected in time, and the circuit breaker can be set according to the needs of the electrical appliance, so as to expand the scope of use of the circuit breaker, effectively protect the safety of the electrical appliances connected to the circuit breaker, and at the same time improve the service life of the internal components of the circuit breaker.

Description

Technical Field

[0001] The present application relates to the technical field of circuit breakers, and in particular to a circuit breaker short-circuit protection mechanism and an adjustment method thereof. Background Art

[0002] A circuit breaker is a switching device that can close, carry and interrupt current under normal circuit conditions and can close, carry and interrupt current under abnormal circuit conditions within a specified time. It is generally composed of a contact system, arc extinguishing system, operating mechanism, release, casing, etc.

[0003] Circuit breakers can be used to distribute electric energy, start asynchronous motors infrequently, and protect power lines and motors. When they are seriously overloaded or have short circuits or undervoltage faults, they can automatically cut off the circuit. Their function is equivalent to the combination of fuse switches and over- and under-heat relays. And generally, there is no need to change parts after breaking the fault current.

[0004] When a short circuit occurs, the magnetic field generated by the large current (generally 10 to 12 times) overcomes the reaction spring, the release pulls the operating mechanism to operate, and the switch trips instantaneously.

[0005] With respect to the above-mentioned related technologies, when the circuit breaker is produced and assembled, the specifications of the assembled coil are determined, and the magnetic field that can be generated in the coil is a fixed value. However, in different working environments, due to the different specifications of electrical appliances, the current that the internal circuit can withstand is different. When the current inside the electrical appliance is too large and is not enough to generate a magnetic field to push the armature, the circuit breaker cannot be disconnected in time, thereby damaging the internal components of the electrical appliance. In addition, when the current is too large, the temperature of the coil rises. When the coil temperature rises but is not enough to cause the overloaded metal sheet to deform, the continuous high temperature is likely to cause the internal components of the circuit breaker to age faster. When the specifications of the circuit breaker are determined, it is difficult to adjust according to the actual needs of the electrical appliance and it is difficult to meet the needs of on-site work. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present application provides a circuit breaker short-circuit protection mechanism, comprising a circuit breaker mechanism installed inside an insulating housing, the circuit breaker mechanism comprising an armature located inside a coil, a conductive plate is provided at the lower end of the coil, a contact is provided at the lower end of the conductive plate, and a safety mechanism is provided inside the insulating housing and near the coil;

[0007] The safety mechanism comprises a top plate located at the upper end of the armature, a top pin is provided at the lower end of the top plate and close to the armature, a connecting rod assembly is provided at the lower end of the top plate and close to the edge of the coil, a driving assembly is sleeved on the outer side of the connecting rod assembly, and a swinging part is provided at the lower end of the connecting rod assembly, and the swinging part is connected to the contact;

[0008] The connecting rod assembly includes a linkage gear, an upper connecting rod meshing with the linkage gear is provided on one side of the linkage gear, the upper connecting rod is fixedly connected to the top plate, and a lower connecting rod meshing with the linkage gear is provided on the other side of the linkage gear, the lower connecting rod is connected to the swinging part;

[0009] The driving assembly includes a U-shaped frame located outside the linkage gear, a circular groove for the linkage gear shaft to be inserted is opened on the inner wall of the U-shaped frame, an electric push rod is arranged inside the U-shaped frame, a processor is arranged at the upper end of the electric push rod, the processor has a built-in monitoring module, a current controller and a temperature controller, and the current controller and the temperature controller are overlapped with the coil circuit.

[0010] Furthermore, a limit block symmetrically distributed about the upper connecting rod is provided on the outer side of the upper connecting rod, and a limit block symmetrically distributed about the lower connecting rod is provided on the outer side of the lower connecting rod. A rectangular groove for use with the limit block is opened on the inner side wall of the U-shaped frame, and the limit block slides in the rectangular groove.

[0011] Furthermore, the swing part includes a first pin inserted into the lower end of the lower connecting rod, a rocker arm is provided at one end of the first pin, a second pin is provided at the end of the rocker arm away from the first pin, a fixing ring is provided at the center position of the rocker arm, the fixing ring is fixedly connected to the insulating shell, a socket is provided on the lower end surface of the contact and close to the second pin, and the second pin is inserted into the socket.

[0012] Furthermore, the monitoring module is electrically connected to the electric push rod to control the start and stop of the electric push rod. The traveling end of the electric push rod is fixedly connected to the upper connecting rod, and the electric push rod is used to push the upper connecting rod to move.

[0013] Furthermore, the current controller is arranged inside the U-shaped frame, one end of the current controller is electrically connected to the built-in monitoring module of the U-shaped frame, and the ammeter of the current controller is connected in series with the circuit inside the coil.

[0014] Furthermore, the temperature controller is arranged inside the U-shaped frame, one end of the temperature controller is electrically connected to the built-in monitoring module of the U-shaped frame, and the probe of the temperature controller is overlapped with the outer wall of the coil.

[0015] Furthermore, a notch for inserting the lower connecting rod is provided on the outer side of the upper connecting rod and close to the lower connecting rod, and a notch for inserting the upper connecting rod is also provided on the outer side of the lower connecting rod and close to the upper connecting rod.

[0016] A method for adjusting a short-circuit protection mechanism of a circuit breaker based on the above-mentioned method comprises the following steps:

[0017] S1. Setting monitoring threshold: according to power demand, the current threshold of the internal circuit is set through the current controller, and the temperature threshold of the coil is set through the thermostat;

[0018] S2. Circuit closing: When the circuit breaker mechanism is closed, the travel end of the electric push rod is located in the sleeve of the electric push rod, ensuring that the contact and the conductive plate are in contact smoothly, completing the circuit breaker closing work and ensuring that the current path is normal;

[0019] S3. Disconnection protection: When the monitoring module detects that the current of the internal circuit reaches the threshold set by the current controller or the surface temperature of the coil reaches the threshold set by the thermostat, an electrical signal is transmitted to the monitoring module, and the monitoring module energizes the electric push rod;

[0020] S4. Contact disconnection: The monitoring module controls the displacement of the travel end of the electric push rod through an electrical signal, thereby pushing the upper connecting rod downward. The ejector pin hits the armature, causing the armature to move downward. At the same time, the linkage effect of the linkage gear is used to control the lower connecting rod to move upward, causing the rocker arm to swing, causing the end of the contact that contacts the conductive plate to swing downward, thereby disconnecting the contact between the contact and the conductive plate.

[0021] Compared with the known prior art, the technical solution provided by this application has the following beneficial effects:

[0022] 1. The present application sets a safety mechanism, sets a driving assembly and a connecting rod assembly on the outside of the coil, sets the circuit current threshold and temperature threshold through a processor, and uses the connecting rod assembly to disconnect the contact from the conductive plate. When the circuit current of the electrical appliance is overloaded and the magnetic field force of the coil is difficult to push the armature, the internal circuit of the circuit breaker can be disconnected in time. The circuit breaker can be set according to the needs of the electrical appliance, the use range of the circuit breaker can be expanded, the safety of the electrical appliances connected to the circuit breaker can be effectively protected, and the service life of the internal components of the circuit breaker can be increased;

[0023] 2. The present application sets up a connecting rod assembly and utilizes linkage gears to realize synchronous reverse displacement of the upper connecting rod and the lower connecting rod. The upper connecting rod is used to press down to push the armature to move, and the lower connecting rod is used to move up to pull the rocker arm to swing. At the same time, the swing of the rocker arm is used to pull the part of the contact that contacts the conductive plate downward. The swing amplitude of the rocker arm is large and the response speed of the lower connecting rod is fast, which can reduce the space occupied by the safety mechanism and effectively save space inside the insulating casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure in an embodiment of the present application;

[0025] Figure 2 This is a schematic diagram of the structure of the circuit breaker mechanism in the embodiment of the present application;

[0026] Figure 3 This is a schematic diagram of the structure of the insurance institution in the embodiment of the present application;

[0027] Figure 4This is a schematic diagram of the structure of the connecting rod assembly in the embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of the structure of the driving component in the embodiment of the present application;

[0029] Figure 6 This is a schematic diagram of the structure of the swing part in the embodiment of the present application;

[0030] Figure 7 This is a schematic diagram of the structure of the contact in the embodiment of the present application;

[0031] Figure 8 Schematic diagram of the workflow of the processor in the embodiment of the present application.

[0032] In the figure: 1. insulating shell; 2. circuit breaker mechanism; 21. coil; 22. armature; 23. contact; 24. conductive plate; 25. arc extinguishing grid; 3. insurance mechanism; 31. top plate; 32. ejector pin; 33. connecting rod assembly; 331. upper connecting rod; 332. lower connecting rod; 333. linkage gear; 4. driving assembly; 41. U-shaped frame; 42. circular groove; 43. rectangular groove; 44. limit block; 45. electric push rod; 46. processor; 5. swing part; 51. first latch; 52. swing rod; 53. second latch; 54. socket; 55. fixing ring. DETAILED DESCRIPTION

[0033] In order to better understand the above technical solution, Figure 1-8 And specific implementation methods are used to describe the above technical solutions in detail.

[0034] refer to Figure 1 and Figure 2The present application discloses a short-circuit protection mechanism for a circuit breaker, comprising an insulating housing 1, a circuit breaker mechanism 2 and a safety mechanism 3. The circuit breaker mechanism 2 is installed inside the insulating housing 1 and is used to control the closing and opening of the circuit breaker. The circuit breaker mechanism 2 comprises a coil 21, an armature 22, a contact 23, a conductive plate 24 and an arc extinguishing grid 25. The coil 21 is fixedly installed inside the insulating housing 1. The armature 22 is plugged into the inside of the coil 21, and the armature 22 is displaced along the axial direction of the coil 21 inside the coil 21. The contact 23 with a tripping mechanism is installed inside the insulating housing 1 and close to the coil 21. The swing of the contact 23 is controlled by the tripping mechanism. The conductive plate 24 is fixedly installed inside the insulating housing 1 and close to the coil 21, and part of the structure of the conductive plate 24 is located below the coil 21, and the contact 23 is in contact with the conductive plate 24, and the contact between the contact 23 and the conductive plate 24 is used to realize the opening and closing of the circuit. The arc extinguishing grid 25 is installed inside the insulating housing 1 and close to the conductive plate 24. The arc extinguishing grid 25 is used to eliminate the high-voltage arc generated when the circuit is disconnected. The insurance mechanism 3 is installed inside the insulating housing 1 and close to the coil 21. The insurance mechanism 3 is used to assist the circuit breaker mechanism 2 in disconnecting the contact 23 from the conductive plate 24.

[0035] When working, the tripping mechanism is tightened, the wrench of the tripping mechanism is lifted, the armature 22 inside the coil 21 is moved upward, the contact 23 is contacted with the conductive plate 24, and the internal circuit of the circuit breaker is connected. The current enters from the upper end of the coil 21, and then passes out from the lower end of the coil 21. The current passes through the conductive plate 24, and then is connected to the circuit at the lower end of the circuit breaker through the contact 23 overlapped with the conductive plate 24, so as to realize the series connection between the circuit breaker and the electrical circuit, realize the connection of the electrical circuit, and at the same time give the circuit breaker the function of controlling the opening and closing of the electrical circuit. When the internal circuit of the electrical appliance is short-circuited, the current of the internal circuit doubles, the current inside the coil 21 increases, resulting in the enhancement of the magnetic field force inside the coil 21, causing the armature 22 to move, and the armature 22 strikes the contact 23 and the tripping mechanism downward, so that the tripping mechanism drives the contact 23 to swing, and then the wrench of the tripping mechanism swings downward, the internal circuit of the circuit breaker is disconnected, and the internal circuit of the electrical appliance is protected. At the same time, the insurance mechanism 3 is used to assist the circuit breaking structure. By setting the insurance mechanism 3, when necessary, the insurance mechanism 3 is used to trigger the circuit breaking mechanism 2 in advance, so that the tripping mechanism of the circuit breaker works and the contact 23 is disconnected from the conductive plate 24 in advance.

[0036] refer to Figures 2 to 7The safety mechanism 3 includes a top plate 31, an ejector pin 32, a connecting rod assembly 33, a driving assembly 4 and a swinging part 5. The top plate 31 is fixedly mounted inside the insulating housing 1 and close to the armature 22, and the ejector pin 32 is fixedly mounted on the lower end surface of the top plate 31 and close to the armature 22. The connecting rod assembly 33 is mounted on the lower end surface of the top plate 31 and close to the ejector pin 32. The connecting rod assembly 33 includes an upper connecting rod 331, a lower connecting rod 332 and a linkage gear 333. The upper connecting rod 331 is fixedly mounted on the lower end surface of the top plate 31 and close to the ejector pin 32, and the upper end surface of the upper connecting rod 331 is fixedly connected to the top plate 31, and the upper connecting rod 331 is located next to the coil 21. The lower connecting rod 332 is mounted on the outer side of the upper connecting rod 331 and close to the lower end. The linkage gear 333 is installed between the upper connecting rod 331 and the lower connecting rod 332, and the linkage gear 333 is meshed and connected with the upper connecting rod 331, and at the same time, the linkage gear 333 is meshed and connected with the lower connecting rod 332. A notch is provided at the lower end of the upper connecting rod 331 and close to the lower connecting rod 332, and a notch is provided at the upper end of the lower connecting rod 332 and close to the upper connecting rod 331. The lower end of the upper connecting rod 331 can be spliced ​​with the upper end of the lower connecting rod 332 to reduce the space occupied by the connecting rod assembly 33. The driving assembly 4 is installed on the outside of the linkage gear 333. The swinging part 5 is installed inside the insulating housing 1 and close to the contact 23.

[0037] The driving assembly 4 includes a U-shaped frame 41, a stopper 44, an electric push rod 45 and a processor 46. The U-shaped frame 41 is fixedly installed inside the insulating housing 1 and close to the linkage gear 333, and the linkage gear 333 is installed inside the U-shaped frame 41 and close to the center. A circular groove 42 for plugging the rotating shaft of the linkage gear 333 is provided on the inner side wall of the U-shaped frame 41, and the linkage gear 333 rotates in the circular groove 42 inside the U-shaped frame 41. The stopper 44 is fixedly installed on the outer side of the upper connecting rod 331 and close to the linkage gear 333. Similarly, the stopper 44 is also installed on the outer side of the lower connecting rod 332 and close to the linkage gear 333. The lower end of the upper connecting rod 331 is plugged into the inside of the U-shaped frame 41, and the upper end of the lower connecting rod 332 is plugged into the inside of the U-shaped frame 41. A rectangular groove 43 is provided on the inner side wall of the U-shaped frame 41 and close to the stopper 44, and the stopper 44 slides in the rectangular groove 43. The upper connecting rod 331 and the lower connecting rod 332 are slidably connected to the rectangular groove 43 through the stop block 44 to achieve displacement. When the upper connecting rod 331 is displaced, since the linkage gear 333 is meshed and connected with the upper connecting rod 331 and the lower connecting rod 332 on both sides at the same time, the lower connecting rod 332 will move in the opposite direction of the movement of the upper connecting rod 331 along with the displacement of the upper connecting rod 331. The electric push rod 45 is fixedly installed inside the U-shaped frame 41, and the travel end of the electric push rod 45 is fixedly connected to the lower end of the upper connecting rod 331. The displacement of the upper connecting rod 331 is controlled by the displacement of the travel end of the electric push rod 45.

[0038] The swinging part 5 includes a first latch 51, a swing rod 52, a second latch 53 and a fixing ring 55. A through hole is provided at the lower end of the lower connecting rod 332, and the first latch 51 is inserted into the through hole at the lower end of the lower connecting rod 332. The swing rod 52 is fixedly mounted at one end of the first latch 51, and the swing rod 52 and the lower connecting rod 332 do not interfere with each other. The second latch 53 is fixedly mounted at one end of the swing rod 52 away from the first latch 51. A socket 54 is provided at one end of the contact 23 close to the conductive plate 24, and the second latch 53 is inserted into the socket 54 at one end of the contact 23, and the second latch 53 can rotate in the socket 54. The fixing ring 55 is fixedly mounted inside the insulating housing 1 and close to the center of the swing rod 52, and the fixing ring 55 is rotatably connected to the swing rod 52. The swing rod 52 is configured as a Z-shaped rod, and the length of the central connecting rod of the swing rod 52 can be adjusted according to installation requirements, so that the swing rod 52 is located close to the contact 23 but does not touch the contact 23, thereby reducing the space required for the installation of the swing rod 52 as much as possible.

[0039] After the circuit breaker is closed, the armature 22 is located inside the coil 21 and near the upper end, the contact 23 contacts the conductive plate 24, and the travel end of the electric push rod 45 is retracted into the sleeve of the electric push rod 45. When the contact 23 needs to be disconnected from the conductive plate 24, the electric push rod 45 is energized to extend the travel end of the electric push rod 45, driving the upper connecting rod 331 to move in the direction of the lower connecting rod 332. Since the linkage gear 333 is meshed and connected with the upper connecting rod 331 and the lower connecting rod 332 at the same time, and the upper connecting rod 331 is located on one side of the linkage gear 333, and the lower connecting rod 332 is located on the other side of the linkage gear 333, when the upper connecting rod 331 moves in the direction of the lower connecting rod 332, the lower connecting rod 332 moves synchronously in the direction of the upper connecting rod 331 under the action of the linkage gear 333. Thus, the upper connecting rod 331 moves downward under the action of the electric push rod 45, and at the same time, the top plate 31 and the ejector pin 32 move toward the direction of the armature 22, and the ejector pin 32 pushes the armature 22 to move downward, so that the armature 22 pushes the contact 23. When the upper connecting rod 331 moves downward, the lower connecting rod 332 is lifted upward by the linkage gear 333, and the first latch 51 at one end of the swing rod 52 is inserted into the through hole at the lower end of the lower connecting rod 332. When the lower connecting rod 332 moves upward, the end of the swing rod 52 connected to the lower connecting rod 332 swings upward, and the other end of the swing rod 52 swings downward. Since the end of the swing rod 52 swinging downward is connected to the contact 23 through the second latch 53, when the swing rod 52 swings, the contact 23 is driven to bend downward, so that the contact 23 is out of contact with the conductive plate 24. After the contact 23 is disconnected from the conductive plate 24, the internal circuit of the circuit breaker will be in a disconnected state. After the armature 22 moves down and hits the contact 23, the tripping mechanism connected to the contact 23 moves in tandem, causing the tripping mechanism wrench to rotate downward, and the tripping mechanism wrench rebounds to the position before closing. When the circuit breaker needs to connect the circuit, the tripping mechanism wrench needs to be moved to the closing position again, thereby moving the armature 22 above the coil 21.

[0040] refer to Figure 5 and Figure 8 The processor 46 is fixedly mounted on the upper end of the electric push rod 45, and the processor 46 is located inside the U-shaped frame 41. The processor 46 has a built-in monitoring module, a current controller and a temperature controller. The current controller is used to set the current threshold of the internal circuit of the coil 21, and the current controller is connected in series with the internal circuit of the coil 21. The temperature controller is used to set the temperature threshold of the surface of the coil 21, and the temperature controller overlaps the outer wall of the coil 21.

[0041] It is worth mentioning that the current controller has a built-in ammeter, while the temperature controller has a built-in thermometer. The ammeter is used to detect the current size of the coil 21 circuit, and the thermometer is used to detect the temperature size of the outer wall of the coil 21. When the ammeter detects that the current size reaches the current threshold value set by the current controller, the monitoring module sends an electrical signal to the electric push rod 45 to control the extension of the travel end of the electric push rod 45. When the thermometer detects that the surface temperature of the coil 21 reaches the threshold value of the thermostat, the monitoring module sends an electrical signal to the electric push rod 45 to control the extension of the travel end of the electric push rod 45.

[0042] Before the circuit breaker is closed, the circuit breaker is set by the current controller and the temperature controller. The current threshold and the temperature threshold are set according to the needs of the electrical appliances. After the internal circuit of the circuit breaker is closed, the built-in ammeter of the current controller detects the current of the coil 21. When the current of the coil 21 reaches the current threshold set by the current controller, the current controller sends an electrical signal to the monitoring module, and the monitoring module controls the electric push rod 45 to start. The moving end of the electric push rod 45 extends, causing the upper connecting rod 331 to move in the direction of the lower connecting rod 332. The upper connecting rod 331 drives the top plate 31 to move downward, so that the ejector pin 32 at the lower end of the top plate 31 pushes the armature 22 to move, and then the armature 22 pushes the contact 23. At the same time, the lower connecting rod 332 is displaced in the direction of the upper connecting rod 331 under the action of the linkage gear 333, so that the contact 23 is disconnected from the conductive plate 24, and the internal circuit of the circuit breaker is cut off.

[0043] Similarly, when the temperature of the outer wall of the coil 21 reaches the temperature threshold set by the thermostat, the thermostat sends an electrical signal to the monitoring module, which then controls the electric push rod 45 to push the upper connecting rod 331 to move, thereby disconnecting the contact 23 from the conductive plate 24 and cutting off the internal circuit of the circuit breaker.

[0044] A method for adjusting a short-circuit protection mechanism of a circuit breaker comprises the following steps:

[0045] S1. Setting the monitoring threshold: According to the power demand, the current threshold of the internal circuit is set by the current controller, and the temperature threshold of the coil 21 is set by the thermostat;

[0046] S2. Circuit closing: When the circuit breaker breaking mechanism 2 is closed, the travel end of the electric push rod 45 is located in the sleeve of the electric push rod 45, ensuring that the contact 23 and the conductive plate 24 are in contact with each other smoothly, completing the circuit breaker closing work and ensuring that the current path is normal;

[0047] S3 disconnect protection: when the monitoring module detects that the current of the internal circuit reaches the threshold value set by the current controller or the surface temperature of the coil 21 reaches the threshold value set by the thermostat, an electrical signal is transmitted to the monitoring module, and the monitoring module energizes the electric push rod 45;

[0048] S4. Contact disconnection: The monitoring module controls the displacement of the travel end of the electric push rod 45 through an electrical signal, thereby pushing the upper connecting rod 331 downward, and the ejector pin 32 hits the armature 22, causing the armature 22 to move downward. At the same time, the linkage effect of the linkage gear 333 is used to control the lower connecting rod 332 to move upward, causing the swing rod 52 to swing, causing the end of the contact 23 that contacts the conductive plate 24 to swing downward, thereby disconnecting the contact between the contact 23 and the conductive plate 24.

[0049] The working principle of the embodiment of this application:

[0050] Before the circuit breaker is closed, the current controller is used to set the current threshold of the internal circuit, and the temperature threshold of the outer wall of the coil 21 is set by the temperature controller. After the circuit breaker is closed, the circuit path of the electrical appliance is normal. When the ammeter inside the current controller detects that the current at the coil 21 reaches the set current threshold, the electric push rod 45 is controlled to move through the monitoring module, and the upper connecting rod 331 is pushed to move in the direction of the lower connecting rod 332 by the electric push rod 45. At the same time, the lower connecting rod 332 is driven to move in the direction of the upper connecting rod 331 through the linkage gear 333, and then the end of the swing rod 52 with the first pin 51 is lifted, so that the end of the swing rod 52 with the second pin 53 swings downward, and the part of the traction contact 23 in contact with the conductive plate 24 is bent downward, and the contact 23 is disconnected from the conductive plate 24, so that the internal circuit of the circuit breaker is disconnected.

[0051] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A circuit breaker short circuit protection mechanism, comprising a circuit breaker mechanism (2) installed inside an insulating housing (1), the circuit breaker mechanism (2) comprising an armature (22) located inside a coil (21), a conductive plate (24) being provided at the lower end of the coil (21), a contact (23) being provided at the lower end of the conductive plate, characterized in that: A safety mechanism (3) is provided inside the insulating housing and close to the coil (21); The safety mechanism (3) comprises a top plate (31) located at the upper end of the armature (22), a top pin (32) is provided at the lower end of the top plate (31) and close to the armature (22), a connecting rod assembly (33) is provided at the lower end of the top plate (31) and close to the edge of the coil (21), a driving assembly (4) is sleeved on the outer side of the connecting rod assembly (33), and a swinging portion (5) is provided at the lower end of the connecting rod assembly (33), and the swinging portion (5) is connected to the contact (23); The connecting rod assembly (33) comprises a linkage gear (333), an upper connecting rod (331) meshingly connected to the linkage gear (333) is provided on one side of the linkage gear (333), the upper connecting rod (331) is fixedly connected to the top plate (31), and a lower connecting rod (332) meshingly connected to the linkage gear (333) is provided on the other side of the linkage gear (333), the lower connecting rod (332) is connected to the swinging portion (5); The driving assembly (4) comprises a U-shaped frame (41) located outside the linkage gear (333); a circular groove (42) for inserting the shaft of the linkage gear (333) is provided on the inner side wall of the U-shaped frame (41); an electric push rod (45) is provided inside the U-shaped frame (41); a processor (46) is provided at the upper end of the electric push rod (45); the processor (46) has a built-in monitoring module, a current controller and a temperature controller; the monitoring module is electrically connected to the electric push rod (45); one end of the current controller is electrically connected to the built-in monitoring module of the U-shaped frame (41); the ammeter of the current controller is connected in series with the internal circuit of the coil (21); one end of the temperature controller is electrically connected to the built-in monitoring module of the U-shaped frame (41); and the probe of the temperature controller overlaps the outer side wall of the coil (21); Based on the above circuit breaker short-circuit protection mechanism, the following use steps are included: S1. Setting the monitoring threshold: According to the power demand, the current threshold of the internal circuit is set by the current controller, and the temperature threshold of the coil (21) is set by the thermostat; S2. Circuit closing: When the circuit breaker breaking mechanism (2) is closed, the travel end of the electric push rod (45) is located in the sleeve of the electric push rod (45), ensuring that the contact (23) and the conductive plate (24) are in contact with each other smoothly, completing the circuit breaker closing operation and ensuring that the current path is normal; S3. Disconnection protection: When the monitoring module detects that the current of the internal circuit reaches the threshold set by the current controller or the surface temperature of the coil (21) reaches the threshold set by the thermostat, an electrical signal is transmitted to the monitoring module, and the monitoring module energizes the electric push rod (45); S4. Contact disconnection: The monitoring module controls the displacement of the travel end of the electric push rod (45) through an electrical signal, thereby pushing the upper connecting rod (331) downward, causing the ejector pin (32) to hit the armature (22), causing the armature (22) to move downward, and at the same time, utilizing the linkage effect of the linkage gear (333) to control the lower connecting rod (332) to move upward, causing the swing rod (52) to swing, causing the end of the contact (23) in contact with the conductive plate (24) to swing downward, thereby disconnecting the contact between the contact (23) and the conductive plate (24).

2. A circuit breaker short circuit protection mechanism according to claim 1, characterized in that: The outer side of the upper connecting rod (331) is provided with a limit block (44) symmetrically distributed with respect to the upper connecting rod (331); the outer side of the lower connecting rod (332) is provided with a limit block (44) symmetrically distributed with respect to the lower connecting rod (332); the inner side wall of the U-shaped frame (41) is provided with a rectangular groove (43) for use with the limit block (44); the limit block (44) slides in the rectangular groove (43).

3. A circuit breaker short circuit protection mechanism according to claim 2, characterized in that: The swing portion (5) comprises a first latch (51) plugged into the lower end of the lower connecting rod (332); a swing rod (52) is provided at one end of the first latch (51); a second latch (53) is provided at one end of the swing rod (52) away from the first latch (51); a fixing ring (55) is provided at the center of the swing rod (52); the fixing ring (55) is fixedly connected to the insulating housing (1); a plug hole (54) is provided at a position close to the second plug pin (53) on the lower end surface of the contact (23); and the second plug pin (53) is plugged into the plug hole (54).

4. A circuit breaker short circuit protection mechanism according to claim 3, characterized in that: A notch for inserting the lower connecting rod (332) is provided on the outer side of the upper connecting rod (331) and close to the lower connecting rod (332), and a notch for inserting the upper connecting rod (331) is also provided on the outer side of the lower connecting rod (332) and close to the upper connecting rod (331).

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