Miniature circuit breaker and tripping mechanism thereof

Abstract

The invention provides a miniature circuit breaker and a tripping mechanism thereof, and belongs to the technical field of low-voltage power grid protection equipment.The tripping mechanism comprises a bimetallic assembly, the bimetallic assembly comprises a first bimetallic strip and a second bimetallic strip, and the first bimetallic strip and the second bimetallic strip are each provided with a supporting plate and a connecting base; one end of each of the first bimetallic strip and the second bimetallic strip is fixed on the supporting plate, and the other end of each of the first bimetallic strip and the second bimetallic strip is slidably connected to the supporting plate through a connecting seat; the first bimetallic strip and the second bimetallic strip have the same thermal deformation direction; the two can be deformed as follows: in a cold state, the two can be separated from each other, and in a hot state, the two can be deformed to be in contact with each other; wiring terminals or fourth cables are arranged at the two ends of the first bimetallic strip; the second bimetallic strip is connected with a third cable, the miniature circuit breaker comprises the tripping mechanism, and the structural design of the scheme is beneficial for reducing the performance drift of the miniature circuit breaker in the use process.

Description

Technical Field

[0001] The invention relates to the technical field of low-voltage power grid protection equipment, and in particular to a miniature circuit breaker and a tripping mechanism thereof. Background Art

[0002] Based on the traditional miniature circuit breaker (MCB), the intelligent miniature circuit breaker integrates electronic sensors, microprocessors and communication modules. It not only has overload and short-circuit protection functions, but also can realize remote monitoring, data analysis and intelligent control. With the further popularization and promotion of smart grid technology, the intelligent miniature circuit breaker is an important part of low-voltage grid protection equipment.

[0003] Different from traditional miniature circuit breakers, the functional modules of intelligent miniature circuit breakers include sensor units, control units, and communication units. The sensor unit is used to collect parameters such as current, voltage, power, and power factor of the circuit in real time, and transmit the detection results to the control unit. The control unit is used to determine whether to trigger a protection action (power off) based on the detection results. The communication unit transmits the detection results / action signals of the intelligent miniature circuit breaker, and receives action instructions or other control data from the control center. The use of intelligent miniature circuit breakers not only realizes the power protection function under faults such as overload, short circuit, and leakage, but also, with the assistance of built-in software or other systems (cloud computing systems, user-side mobile phone APPs, etc.), can also realize functions such as circuit remote control, remote monitoring, power consumption law statistics, and risk prediction.

[0004] In order to improve the reliability of intelligent miniature circuit breakers in realizing circuit protection functions, one of the implementation forms of intelligent miniature circuit breakers in the prior art includes an electronic protection system and a mechanical protection system. The above two systems work together to form a "mechanical + electronic" dual protection mechanism. Among them, the electronic protection system is the control unit that triggers the separation of the moving and static contacts through the electromagnetic driver when necessary according to the detection results of the sensor unit to achieve the purpose of power off; the mechanical protection system includes a handle operation module and a bimetallic strip module. The handle operation module drives the transmission module to operate through the operating handle to achieve the purpose of tripping. The bimetallic strip module triggers the tripping mechanism to perform the tripping action through thermal deformation to achieve the purpose of cutting off the circuit. Regarding the use of the bimetallic strip in the circuit breaker, in the prior art, for example, the patent application document with patent application number CN202421208832.8 provides a technical solution for realizing linkage with the tripping part by toggling a pull rod with a bimetallic strip. Others also include connecting the bimetallic strip in series in the main circuit of the circuit, and utilizing the thermal deformation of the bimetallic strip under the load current to trigger the tripping mechanism to cut off the circuit, such as the technical solution provided by patent application number CN202411422561.0.

[0005] In intelligent miniature circuit breakers, the bimetallic strip has a direct impact on the performance of the tripping mechanism. In order to improve the stability of the intelligent miniature circuit breaker, it is necessary to optimize the corresponding structure. Summary of the invention

[0006] In view of the above-mentioned problem of optimizing the stability of the intelligent miniature circuit breaker, the present invention provides a miniature circuit breaker and a tripping mechanism thereof. The structural design of the present solution is beneficial to reducing the performance drift of the miniature circuit breaker during use.

[0007] In view of the above problems, the miniature circuit breaker and the tripping mechanism thereof provided by the present invention solve the problems through the following technical points: the miniature circuit breaker tripping mechanism comprises a bimetallic component, the bimetallic component comprises a first bimetallic sheet and a second bimetallic sheet, the first bimetallic sheet and the second bimetallic sheet are both provided with a support plate and a connecting seat; The first bimetallic strip and the second bimetallic strip are: One end is fixed to the support plate, and the other end is slidably connected to the support plate through a connecting seat; The first bimetallic strip and the second bimetallic strip have the same thermal deformation direction; The two can be deformed such that: in a cold state, the two are separated from each other, and in a hot state, the two can be deformed such that the middle part of the first bimetallic strip contacts the middle part of the second bimetallic strip; Both ends of the first bimetallic strip are provided with a connection terminal or a fourth cable for connecting the first bimetallic strip in series in the main circuit of the miniature circuit breaker circuit; The second bimetallic strip is connected to a third cable for connecting the second bimetallic strip in series with the electromagnetic coil.

[0008] When the present solution is used, the first bimetallic strip is connected in series in the main circuit of the miniature circuit breaker, specifically: the incoming line end of the miniature circuit breaker is connected to the static contact through the first cable, the moving contact is connected to the terminal at one end of the first bimetallic strip through the second cable, the terminal is connected to the first bimetallic strip through a spiral cable with an elastic spiral structure, and the other end of the first bimetallic strip is connected to the outgoing line end of the miniature circuit breaker through a fourth cable. The second bimetallic strip is used to establish a passage for the series electromagnetic coil, specifically: when the first bimetallic strip is deformed to contact with the second bimetallic strip under the action of the load current, the first bimetallic strip is connected to the second bimetallic strip, and part of the current is transmitted to the electromagnetic coil through the second bimetallic strip. The magnetic force generated by the electromagnetic coil under the current forces the moving iron core on the tripping drive unit to drive the moving contact to move in a direction away from the static contact, and the moving contact moves to separate from the static contact, so as to achieve the tripping of the miniature circuit breaker.

[0009] This solution aims at the bimetallic strip during use. Due to extreme temperature (related to the material of the bimetallic strip, usually above 1500°C, this condition is not easy to occur under normal overload and normal tripping conditions of the miniature circuit breaker) and cyclic stress (alternating stress caused by frequent deformation caused by frequent current changes), the bimetallic strip will produce permanent creep deformation after being used for a period of time. In the prior art, the bimetallic strip on the miniature circuit breaker is mostly installed in a way that one end is fixed and the other end is a cantilever end. Under this installation method, the above creep deformation will amplify the position offset of the cantilever end of the bimetallic strip. For the structure that uses a bimetallic strip to realize the conduction of the electromagnetic coil circuit, the above creep deformation will cause the current / deformation that triggers the electromagnetic coil to change (usually become smaller), causing the performance of the miniature circuit breaker to drift during use.

[0010] This solution is different from the prior art in that: First, it is set that the first bimetallic strip and the second bimetallic strip are both fixed on the support plate configured for each at one end, and the other end is slidably connected to the support plate configured for each through a connecting seat. In this way, when the first bimetallic strip and the second bimetallic strip are deformed, one end of each slidably connected to the support plate is subject to the pulling constraint of the support plate, and each of the ends slides relative to the support plate, causing the first bimetallic strip and the second bimetallic strip to deform concavely / convexly in the middle. For the creep deformation that inevitably occurs on the first bimetallic strip and the second bimetallic strip, since the support plate has pulling constraints on both ends of each, compared with the constraint method in which the active end of the bimetallic strip is in a free deformation state used in the prior art, for realizing the current conduction of the electromagnetic coil by contacting the middle part of the first bimetallic strip with the middle part of the second bimetallic strip, this method can effectively reduce the accumulated creep deformation occurring in the first bimetallic strip and the second bimetallic strip, thereby achieving the purpose of reducing the performance drift of the miniature circuit breaker during use from the perspective of creep deformation.

[0011] Secondly, when the first bimetallic strip works at different ambient temperatures, the current on the first bimetallic strip determines the heat it generates, and the ambient temperature determines the surface heat dissipation capacity of the first bimetallic strip. Therefore, the actual temperature rise rate on the first bimetallic strip is determined by the heat generated by the load current and the heat dissipation capacity determined by the ambient temperature. This solution is configured to establish an electrical connection between the first bimetallic strip and the electromagnetic coil through the second bimetallic strip, and to configure the first bimetallic strip and the second bimetallic strip to have the same thermal deformation direction. In this way, when the ambient temperature is high, the first bimetallic strip is prone to obtain a larger deformation at a smaller current / time due to its reduced heat dissipation capacity. Before the first bimetallic strip contacts the second bimetallic strip, the deformation of the second bimetallic strip is affected by the ambient temperature. When the second bimetallic strip is used When the second bimetallic strip establishes conduction between the first bimetallic strip and the electromagnetic coil, the ambient temperature will cause the second bimetallic strip to deform in the same direction as the first bimetallic strip. Compared with the fixed-position contacts used to establish conduction between the electromagnetic coil and the first bimetallic strip, when the ambient temperature is low, the deformation of the first bimetallic strip required for the first bimetallic strip to contact the second bimetallic strip is smaller. When the ambient temperature is high, the deformation of the first bimetallic strip required for the first bimetallic strip to contact the second bimetallic strip is larger. Therefore, from the perspective of ambient temperature, this scheme uses the thermal deformation occurring on the second bimetallic strip to change the actual deformation of the first bimetallic strip when the first bimetallic strip contacts the second bimetallic strip. From the perspective of ambient temperature, this scheme is beneficial to reducing the performance drift of the miniature circuit breaker during use.

[0012] In specific application, the first bimetallic strip and the second bimetallic strip can be set to be suspended and supported on their respective support plates. When both the first bimetallic strip and the second bimetallic strip are in a cold state (at room temperature), the two are parallel to each other, and the deformation capacity of the layer structure of the first bimetallic strip on the side close to the second bimetallic strip is greater than the deformation capacity of the other side, and the deformation capacity of the layer structure of the second bimetallic strip on the side close to the first bimetallic strip is less than the deformation capacity of the other side. The first bimetallic strip and the second bimetallic strip are set in a closed component box so that the inside of the component box has stable heat dissipation conditions to avoid the influence of external airflow on the operation of the bimetallic component. When in use, the component box is fixed in the housing of the miniature circuit breaker.

[0013] As a further technical solution of the miniature circuit breaker tripping mechanism: It also includes a component box, in which two supporting plates parallel to each other are arranged; The first bimetallic strip and the second bimetallic strip are respectively mounted on different support plates and are located in the gap between the two support plates; Each support plate has: a strip hole extending along the length direction of the support plate is set at one end of the support plate, and a circular hole is set at the other end of the support plate, the circular hole is used to realize the fixed connection between the first bimetallic strip, the second bimetallic strip and the support plate, and the strip hole is used to realize the sliding connection between the first bimetallic strip, the second bimetallic strip and the support plate.

[0014] The above provides a complete set of tripping mechanism technical solutions, the component box is used to encapsulate the corresponding bimetallic strip, the support plate is used as a fixing seat for the corresponding bimetallic strip in the component box, the circular hole is used to fix the corresponding bimetallic strip on the support plate, and the strip hole is used to achieve sliding connection between the corresponding bimetallic strip and the support plate. In the specific implementation method, the circular hole is used as a fixing screw hole, and the connecting seat is slidably connected to the strip hole and pulled on the support plate.

[0015] The connecting seat comprises a connecting screw, one end of which is provided with two layers of clamping blocks, each layer of clamping blocks having a clamping block on each side of a pair of opposite sides of the connecting screw; In the axial direction of the connecting screw, the two layers of the card blocks are in a stacked relationship facing each other, and a card slot is formed between the two layers of the card blocks. The width of the card slot satisfies: one end of the connecting screw with the card block is embedded in the strip hole, and the end of the connecting screw is connected to the support plate through the card slot; The width of the card block satisfies: the width of the card block is smaller than the width of the strip hole; The other end of the connecting screw is provided with an external thread, and the connecting seat locks the first bimetallic strip and the second bimetallic strip between the nut and the clamping block through a nut threadedly connected to the external thread.

[0016] The above scheme provides a specific implementation form of the connecting seat, specifically: two layers of card blocks form a baffle for being set on different sides of the support plate, the width of the card slot is greater than or equal to the thickness of the support plate, and when the connecting seat is installed, the angle of the connecting screw can be first adjusted to the direction of the pair of opposite sides being parallel to the direction of the strip hole, and then the connecting screw can be rotated 90°. For example, the two layers of card blocks are defined as the bottom layer close to the end of the connecting screw and the top layer away from the end. After rotating the connecting screw, the bottom layer fits with the back side of the support plate, and the top layer fits with the front side of the support plate. Then, the corresponding bimetallic strip is locked on the connecting screw by a nut threadedly connected to the external thread. At this time, the corresponding bimetallic strip provides an anti-rotation constraint for the connecting screw, thereby constraining the angle of the connecting screw relative to the strip hole, and utilizing the matching relationship between the support plate and the card slot to achieve a sliding state along the support plate while pulling the corresponding bimetallic strip. In the specific implementation process, since the bimetallic component may experience frequent temperature fluctuations depending on the load current, in order to avoid the loss of the matching relationship between the connecting seat and the support plate after the nut and the connecting screw are loosened and to ensure the performance stability of the bimetallic component, it is advisable to set an elastic pad between the top layer and the bimetallic strip or between the bimetallic strip and the nut to prevent the connecting screw from rotating through continuous elastic force. The connecting seat provided above has a simple structure and can use the stable width of the card slot to constrain the corresponding bimetallic strip to slide on the support plate and provide a pulling constraint for the corresponding bimetallic strip.

[0017] One end of the first bimetallic strip that is slidably connected to the support plate is provided with a spiral cable, the terminal block is fixed on the component box, one end of the spiral cable is connected to the first bimetallic strip, and the other end of the spiral cable is connected to the terminal block. In the above scheme, in view of the fact that the first bimetallic strip has a large deformation under load current, the elastic expansion and contraction generated by the spiral cable is used to adapt to the deformation of the first bimetallic strip, so as to avoid irregular deformation of the cable between the first bimetallic strip and the terminal block under the pulling of the first bimetallic strip, resulting in cable damage, etc.

[0018] It also includes a conductive sheet arranged in the middle of the first bimetallic sheet. The conductive sheet is located on a side of the first bimetallic sheet close to the second bimetallic sheet, and the conductive sheet protrudes relative to the surface of the first bimetallic sheet.

[0019] The above scheme is intended to address the following problems: when the first bimetallic strip undergoes thermal deformation due to temperature increase, an arched structure is formed in its middle relative to the support plate connected thereto and moves toward the second bimetallic strip. At this time, the second bimetallic strip undergoes deformation in the middle relative to the support plate connected thereto due to the increase in ambient temperature. The deformation characteristics of the above two bimetallic strips make both of them have the characteristic of deforming into an arc structure. In order to make the two bimetallic strips have a stable contact position and accurately control the deformation amount of the two bimetallic strips when contact occurs, it is configured to also include the conductive sheet, which is a conductive structure at the top of the arch when the first bimetallic strip is deformed and is a protruding structure. The passive layer for contacting the second bimetallic strip is used to power the electromagnetic coil. Compared with direct contact between the two bimetallic strips, the conductive sheet protruding relative to the surface of the first bimetallic strip can not only stabilize the contact position of the circuit conduction at the conductive sheet position, but also, for the first bimetallic strip and the second bimetallic strip that have been selected and installed, by controlling the thickness of the conductive sheet, the deformation amount of the two bimetallic strips when contact occurs can be accurately controlled.

[0020] Preferably, the bimetallic strip used in the miniature circuit breaker usually has the characteristic that the conductivity of the active layer is weaker than that of the passive layer. For the first bimetallic strip and the second bimetallic strip arranged side by side, in order to ensure that the first bimetallic strip can contact the second bimetallic strip after being deformed under the thermal effect of the load current, the layer structure of the first bimetallic strip close to the second bimetallic strip is the active layer, and the layer structure of the second bimetallic strip close to the first bimetallic strip is the passive layer. In order to optimize the electrical connection quality between the conductive strip and the first bimetallic strip and to improve the performance stability of the electromagnetic coil, the conductive strip is configured as a protruding structure integrally formed on the passive layer of the first bimetallic strip, and the protruding structure passes through the active layer through the hole on the active layer of the first bimetallic strip. When the thickness of the conductive strip needs to be controlled, a protruding structure of suitable thickness is selected or grinding is performed on the basis of the original thickness.

[0021] A more complete configuration is to further include an electromagnetic coil connected to a third cable. In this solution, the third cable is a cable that establishes a conductive relationship between the electromagnetic coil and the second bimetallic strip. The third cable is connected to one of the terminals of the electromagnetic coil, and the other terminal of the electromagnetic coil is connected to the neutral wire or the ground wire in the distribution box. The moving contact and the static contact are connected in series to the live wire to control the conductive state of the live wire.

[0022] It also includes a linkage device, which is used to realize the linkage between the bimetal component and the handle operation module of the miniature circuit breaker; The linkage is as follows: the bimetal component pushes one end of the linkage device to swing through the thermally deformed first bimetallic sheet or the second bimetallic sheet, and the other end of the linkage device swings synchronously and drives the handle operating module to swing in the direction of achieving the tripping of the miniature circuit breaker.

[0023] The above scheme aims to provide a purely mechanical tripping scheme, which is used to realize that when the electromagnetic driver including the electromagnetic coil cannot work normally, the linkage device is used to drive the handle operation module to operate, so as to realize the tripping of the miniature circuit breaker. Specifically, when the first bimetallic strip is overloaded and causes a large amount of deformation, it pushes one end of the linkage device to swing, and the synchronous swing occurring at the other end of the linkage device provides a driving force for the handle operation module to operate, so that the handle operation module swings in the direction of realizing the tripping of the miniature circuit breaker to cut off the circuit, thereby achieving the purpose of providing a guarantee for the miniature circuit breaker to perform the tripping action.

[0024] It also includes a component box, in which the first bimetallic strip and the second bimetallic strip are both installed; The linkage device comprises a swing rod rotatably connected to the component box, one end of the swing rod is embedded in the component box, and the end of the swing rod is located on the thermal deformation track of the first bimetallic strip or the second bimetallic strip; the other end of the swing rod is used to connect with the handle operation module; Wherein, when the linkage device realizes the phase linkage, the rocker rod serves as a laborious lever.

[0025] The above provides a specific bimetal component, linkage device structure and matching form. In the above scheme, the component box serves as the external shell of the bimetal component, and the swing rod is rotatably connected to the component box. When the first bimetallic strip or the second bimetallic strip (the first bimetallic strip is preferably used because the deformation of the second bimetallic strip under fault conditions has hysteresis) deforms to push the swing rod to swing, the other end of the swing rod acts on the handle operating module to drive the handle operating module to perform the action of tripping the miniature circuit breaker. Setting the swing rod as a laborious lever means that: relative to the connection point of the swing rod on the component box, the force arm on the action side of the first bimetallic strip or the second bimetallic strip is shorter than the force arm on the action side of the handle operating module, relative to the deformation of the corresponding bimetallic strip, it is used to amplify the action stroke of the swing rod on the handle operating module.

[0026] The present solution also relates to a miniature circuit breaker, comprising a tripping drive unit, a moving contact connected to the tripping drive unit, a stationary contact fixed in the miniature circuit breaker, and a circuit main circuit cable, and also comprises a miniature circuit breaker tripping mechanism as described in any one of the above items, wherein the circuit main circuit cable comprises a first cable and a second cable, wherein the first cable is used as a cable between the stationary contact and the miniature circuit breaker inlet terminal, and the miniature circuit breaker tripping mechanism is installed as follows: The second cable serves as a cable between the moving contact and one end of the first bimetallic strip, and also includes a fourth cable, which serves as a cable between the other end of the first bimetallic strip and the output terminal of the miniature circuit breaker. The third cable is used to realize the series connection of the second bimetallic strip and the electromagnetic coil of the tripping drive unit.

[0027] The above scheme is: the first bimetallic strip is connected in series to the main circuit of the miniature circuit breaker through the first cable, the static contact, the moving contact, and the second cable, and the second bimetallic strip is electrically connected to the electromagnetic coil of the tripping drive unit through the third cable. When the first bimetallic strip and the second bimetallic strip are connected to provide a driving current for the electromagnetic coil, the moving iron core of the tripping drive unit drives the moving contact to separate from the static contact, thereby achieving the purpose of circuit cutting protection. This scheme is a technical scheme including the tripping mechanism.

[0028] As a further technical solution of the miniature circuit breaker: It also includes a sensor unit, a control unit and a communication unit, wherein the sensor unit is used to collect one or more of the current, voltage, power, power factor and frequency parameters on the main circuit of the circuit, and transmit the detection result to the control unit; The control unit is used to determine whether to trigger the power-off protection action according to the detection result, and when it is determined that the power-off protection action is triggered, control the tripping drive unit to act so as to drive the moving contact to move to a state separated from the static contact; The communication unit is used to perform one or more of the following actions: Transmitting the detection results of the sensor unit to the remote monitoring terminal; Transmitting the action signal of the tripping drive unit to the remote monitoring terminal; Receive control instructions from the remote monitoring end to the miniature circuit breaker, and transmit the control instructions to the control unit; The control instruction includes an action instruction and a built-in parameter of the miniature circuit breaker, wherein the action instruction is an instruction for controlling the miniature circuit breaker to trip, and the built-in parameter is a threshold parameter built into the miniature circuit breaker for determining whether to trigger a power-off protection action.

[0029] The above scheme aims to provide an intelligent miniature circuit breaker, specifically: the control unit determines whether to trigger the power-off protection action according to the detection signal of the sensor unit, and the communication unit is used to realize one or more of the line detection function, the line working state feedback function, the line remote control function, and the miniature circuit breaker working parameter remote adjustment function. Therefore, this scheme is an intelligent miniature circuit breaker including an electronic protection system.

[0030] The present invention has the following beneficial effects: First of all, compared with the constraint method used in the prior art in which the active end of the bimetallic strip is in a free deformation state, this solution adopts the contact between the middle part of the first bimetallic strip and the middle part of the second bimetallic strip to realize the current conduction of the electromagnetic coil. This method can effectively reduce the cumulative creep deformation occurring in the first bimetallic strip and the second bimetallic strip, thereby achieving the purpose of reducing the performance drift of the miniature circuit breaker during use from the perspective of creep deformation.

[0031] Secondly, from the perspective of ambient temperature, this solution utilizes the thermal deformation occurring on the second bimetallic strip to change the actual deformation of the first bimetallic strip when the first bimetallic strip contacts the second bimetallic strip. From the perspective of ambient temperature, this solution is beneficial for reducing the performance drift of the miniature circuit breaker during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the internal structure of a specific miniature circuit breaker embodiment in this scheme; Figure 2 for Figure 1 A partial enlarged view of the middle A part; Figure 3 A cross-sectional view of a specific bimetallic component embodiment in the present scheme; Figure 4 This is a front view of a specific support plate embodiment in this solution; Figure 5 This is a front view of a specific embodiment of a connecting seat in this scheme; Figure 6 A top view of a specific embodiment of a connecting seat in this solution; exist Figure 5 and Figure 6 In the figures, the nuts are not shown.

[0033] The reference numerals in the figure are: 1, electromagnetic coil, 2, moving contact, 3, linkage device, 4, static contact, 5, first cable, 6, bimetallic assembly, 7, second cable, 8, terminal block, 9, spiral cable, 10, connecting seat, 11, support plate, 12, first bimetallic sheet, 13, second bimetallic sheet, 14, conductive sheet, 15, third cable, 16, fourth cable, 17, strip hole, 18, circular hole, 19, connecting screw, 20, block, 21, slot, 22, handle operation module, 23, component box. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with embodiments, but the present invention is not limited to the following embodiments: Embodiment 1: like Figures 1 to 6 As shown, the miniature circuit breaker tripping mechanism includes a bimetal component 6, wherein the bimetal component 6 includes a first bimetal strip 12 and a second bimetal strip 13, wherein the first bimetal strip 12 and the second bimetal strip 13 are both provided with a support plate 11 and a connecting seat 10; The first bimetallic strip 12 and the second bimetallic strip 13 are: One end is fixed on the support plate 11, and the other end is slidably connected to the support plate 11 through the connecting seat 10; The first bimetallic strip 12 and the second bimetallic strip 13 both have the same thermal deformation direction; The two can be deformed such that: in a cold state, the two are separated from each other, and in a hot state, the two can be deformed such that the middle part of the first bimetallic strip 12 is in contact with the middle part of the second bimetallic strip 13; Both ends of the first bimetallic strip 12 are provided with a connection terminal 8 or a fourth cable 16 for connecting the first bimetallic strip 12 in series in the main circuit of the miniature circuit breaker circuit; The second bimetallic strip 13 is connected to a third cable 15 for connecting the second bimetallic strip 13 and the electromagnetic coil 1 in series.

[0035] When the present solution is used, the first bimetallic strip 12 is connected in series in the main circuit of the miniature circuit breaker, specifically: the incoming end of the miniature circuit breaker is connected to the static contact 4 through the first cable 5, the moving contact 2 is connected to the wiring terminal 8 at one end of the first bimetallic strip 12 through the second cable 7, the wiring terminal 8 is connected to the first bimetallic strip 12 through the spiral cable 9 with an elastic spiral structure, and the other end of the first bimetallic strip 12 is connected to the outgoing end of the miniature circuit breaker through the fourth cable 16. The second bimetallic strip 13 is used to establish a passage for the series electromagnetic coil 1, specifically: when the first bimetallic strip 12 is deformed to contact with the second bimetallic strip 13 under the action of the load current, the first bimetallic strip 12 and the second bimetallic strip 13 are connected, and part of the current is transmitted to the electromagnetic coil 1 through the second bimetallic strip 13. The magnetic force generated by the electromagnetic coil 1 under the current forces the moving iron core on the tripping drive unit to drive the moving contact 2 to move in a direction away from the static contact 4, and the moving contact 2 moves to separate from the static contact 4, so as to realize the tripping of the miniature circuit breaker.

[0036] This solution aims at the bimetallic strip during use. Due to extreme temperature (related to the material of the bimetallic strip, usually above 1500°C, this condition is not easy to occur under normal overload and normal tripping conditions of the miniature circuit breaker) and cyclic stress (alternating stress caused by frequent deformation caused by frequent current changes), the bimetallic strip will produce permanent creep deformation after being used for a period of time. In addition, since the bimetallic strip on the miniature circuit breaker in the prior art is mostly installed in a way that one end is fixed and the other end is a cantilever end, under this installation method, the above creep deformation will amplify the position offset of the cantilever end of the bimetallic strip. For the structure that uses a bimetallic strip to realize the circuit conduction of the electromagnetic coil 1, the above creep deformation will cause the current / deformation that triggers the operation of the electromagnetic coil 1 to change (usually become smaller), causing the performance of the miniature circuit breaker to drift during use.

[0037] This solution is different from the prior art in that: First, the first bimetallic strip 12 and the second bimetallic strip 13 are both fixed at one end on the support plate 11 configured for each, and the other end is slidably connected to the support plate 11 configured for each through the connecting seat 10. In this way, when the first bimetallic strip 12 and the second bimetallic strip 13 are deformed, one end of each slidably connected to the support plate 11 is pulled and constrained by the support plate 11, and each end slides relative to the support plate 11, so that the first bimetallic strip 12 and the second bimetallic strip 13 are both deformed by a concave / convex middle portion, which is inevitable in the first bimetallic strip 12. The creep deformation on the metal sheet 12 and the second bimetallic sheet 13, since the support plate 11 has a pulling constraint on both ends of each, compared with the constraint method in which the active end of the bimetallic sheet is in a free deformation state used in the prior art, for realizing the current conduction of the electromagnetic coil 1 through the contact between the middle part of the first bimetallic sheet 12 and the middle part of the second bimetallic sheet 13, this method can effectively reduce the cumulative creep deformation occurring in the first bimetallic sheet 12 and the second bimetallic sheet 13, thereby achieving the purpose of reducing the performance drift of the miniature circuit breaker during use from the perspective of creep deformation.

[0038] Secondly, when the first bimetallic strip 12 works at different ambient temperatures, the current on the first bimetallic strip 12 determines the heat generated by it, and the ambient temperature determines the surface heat dissipation capacity of the first bimetallic strip 12. Therefore, the actual temperature rise rate on the first bimetallic strip 12 is determined by the heat generated by the load current and the heat dissipation capacity determined by the ambient temperature. This solution is configured to establish an electrical connection between the first bimetallic strip 12 and the electromagnetic coil 1 through the second bimetallic strip 13, and to configure the first bimetallic strip 12 and the second bimetallic strip 13 to have the same thermal deformation direction. In this way, when the ambient temperature is high, the first bimetallic strip 12 is easy to obtain a larger deformation at a smaller current / time due to its reduced heat dissipation capacity. Before the first bimetallic strip 12 contacts the second bimetallic strip 13, the deformation of the second bimetallic strip 13 is affected by the ambient temperature. When the second bimetallic strip 13 is used When the metal sheet 13 establishes conduction between the first bimetallic strip 12 and the electromagnetic coil 1, the ambient temperature will cause the second bimetallic strip 13 to deform in the same direction as the first bimetallic strip 12. Compared with the fixed-position contacts used to establish conduction between the electromagnetic coil 1 and the first bimetallic strip 12, when the ambient temperature is low, the deformation of the first bimetallic strip 12 required for the first bimetallic strip 12 to contact the second bimetallic strip 13 is smaller. When the ambient temperature is high, the deformation of the first bimetallic strip 12 required for the first bimetallic strip 12 to contact the second bimetallic strip 13 is larger. Therefore, from the perspective of ambient temperature, this scheme uses the thermal deformation occurring on the second bimetallic strip 13 to change the actual deformation of the first bimetallic strip 12 when the first bimetallic strip 12 contacts the second bimetallic strip 13. From the perspective of ambient temperature, this scheme is beneficial to reducing the performance drift of the miniature circuit breaker during use.

[0039] In specific use, the first bimetallic strip 12 and the second bimetallic strip 13 can be set to be suspended and supported on their respective support plates 11. When both the first bimetallic strip 12 and the second bimetallic strip 13 are in a cold state (at room temperature), the two are parallel to each other, and the deformation capacity of the layer structure of the first bimetallic strip 12 on the side close to the second bimetallic strip 13 is greater than the deformation capacity of the other side, and the deformation capacity of the layer structure of the second bimetallic strip 13 on the side close to the first bimetallic strip 12 is less than the deformation capacity of the other side. The first bimetallic strip 12 and the second bimetallic strip 13 are set in a closed component box 23 so that the inside of the component box 23 has stable heat dissipation conditions to avoid the influence of external airflow on the operation of the bimetallic component 6. When in use, the component box 23 is fixed in the housing of the miniature circuit breaker.

[0040] Embodiment 2: This embodiment is further refined on the basis of embodiment 1: It also includes a component box 23, in which two supporting plates 11 parallel to each other are arranged; The first bimetallic strip 12 and the second bimetallic strip 13 are respectively mounted on different support plates 11 and are located in the gap between the two support plates 11; Each support plate 11 has a strip hole 17 extending along the length direction of the support plate 11 at one end of the support plate 11, and a circular hole 18 is provided at the other end of the support plate 11. The circular hole 18 is used to realize the fixed connection between the first bimetallic strip 12 and the second bimetallic strip 13 and the support plate 11, and the strip hole 17 is used to realize the sliding connection between the first bimetallic strip 12 and the second bimetallic strip 13 and the support plate 11.

[0041] The above provides a complete set of tripping mechanism technical solutions, the component box 23 is used to encapsulate the corresponding bimetallic strip, the support plate 11 is used as a fixing seat for the corresponding bimetallic strip in the component box 23, the circular hole 18 is used to fix the corresponding bimetallic strip on the support plate 11, and the strip hole 17 is used to achieve the sliding connection between the corresponding bimetallic strip and the support plate 11. In the specific implementation, the circular hole 18 is used as a fixing screw hole, and the connecting seat 10 is slidably connected in the strip hole 17 and pulled on the support plate 11.

[0042] Embodiment 3: This embodiment is further refined on the basis of Embodiment 2: The connecting seat 10 includes a connecting screw 19, one end of which is provided with two layers of blocks 20, and each layer of blocks 20 has a block 20 on each side of a pair of opposite sides of the connecting screw 19; In the axial direction of the connecting screw 19, the two layers of the blocks 20 are stacked in a mutually opposite relationship, and a slot 21 is formed between the two layers of the blocks 20. The width of the slot 21 satisfies that: one end of the connecting screw 19 having the block 20 is embedded in the strip-shaped hole 17, and the end of the connecting screw 19 is connected to the support plate 11 by the slot 21; The width of the block 20 satisfies: the width of the block 20 is smaller than the width of the strip hole 17; The other end of the connecting screw 19 is provided with an external thread, and the connecting seat 10 locks the first bimetallic strip 12 and the second bimetallic strip 13 between the nut and the clamping block 20 through a nut threadedly connected to the external thread.

[0043] The above scheme provides a specific implementation form of the connection seat 10, specifically: two layers of card blocks 20 form baffles for being set on different sides of the support plate 11, the width of the card slot 21 is greater than or equal to the thickness of the support plate 11, when the connection seat 10 is installed, the angle of the connecting screw 19 can be adjusted to the direction of the pair of opposite sides being parallel to the direction of the strip hole 17, the width of the card block 20 is less than the width of the strip hole 17 so that the card block 20 can smoothly pass through the strip hole 17, and then the connecting screw 19 is rotated 90 degrees, as defined by the two layers of card blocks 20 are close to the connecting screw 19 The bottom layer at the end and the top layer away from the end, after rotating the connecting screw 19, the bottom layer fits with the back of the support plate 11, and the top layer fits with the front of the support plate 11, and then the corresponding bimetallic strip is locked on the connecting screw 19 by a nut threadedly connected to the external thread. At this time, the corresponding bimetallic strip provides an anti-rotation constraint for the connecting screw 19, so as to constrain the angle of the connecting screw 19 relative to the strip hole 17, and utilize the matching relationship between the support plate 11 and the slot 21 to achieve the state of sliding along the support plate 11 while pulling the corresponding bimetallic strip. In the specific implementation process, since the bimetallic component 6 may have frequent temperature fluctuations according to the load current, in order to avoid the loss of the matching relationship between the connecting seat 10 and the support plate 11 after the nut and the connecting screw 19 are loosened, and to ensure the performance stability of the bimetallic component 6, it is preferably set to set an elastic pad between the top layer and the bimetallic strip or between the bimetallic strip and the nut, so as to prevent the connecting screw 19 from rotating through continuous elastic force. The connecting seat 10 provided above has a simple structure, and can utilize the stable width of the slot 21 to constrain the corresponding bimetallic strip to be slidably fitted on the support plate 11, and provide pulling constraints for the corresponding bimetallic strip.

[0044] Embodiment 4: This embodiment is further refined on the basis of Embodiment 2: One end of the first bimetal 12 that is slidably connected to the support plate 11 is provided with a spiral cable 9, the terminal 8 is fixed on the component box 23, one end of the spiral cable 9 is connected to the first bimetal 12, and the other end of the spiral cable 9 is connected to the terminal 8. In the above scheme, in view of the fact that the first bimetal 12 has a large deformation under load current, the elastic expansion and contraction generated by the spiral cable 9 is used to adapt to the deformation of the first bimetal 12, so as to avoid irregular deformation of the cable between the first bimetal 12 and the terminal 8 under the pulling of the first bimetal 12, resulting in cable damage, etc.

[0045] Embodiment 5: This embodiment is further refined on the basis of embodiment 1: It also includes a conductive sheet 14 disposed in the middle of the first bimetallic sheet 12 . The conductive sheet 14 is located on a side of the first bimetallic sheet 12 close to the second bimetallic sheet 13 . The conductive sheet 14 protrudes relative to the surface of the first bimetallic sheet 12 .

[0046] The above scheme is intended to address the following problem: when the first bimetallic strip 12 is thermally deformed due to temperature increase, an arched structure is formed in the middle relative to the support plate 11 connected thereto and faces the second bimetallic strip 13. At this time, the second bimetallic strip 13 is deformed in the middle relative to the support plate 11 connected thereto due to the increase in ambient temperature, and the middle part thereof is deformed toward the support plate 11 connected thereto. The deformation characteristics of the above two bimetallic strips make both of them deform into an arc-shaped structure. In order to make the two bimetallic strips have a stable contact position and accurately control the deformation amount of the two bimetallic strips when contact occurs, it is set to also include The conductive sheet 14 is a protruding structure that serves as an arched top conductive structure when the first bimetallic strip 12 is deformed, and is used to contact the passive layer of the second bimetallic strip 13 to realize power supply for the electromagnetic coil 1. Compared with the direct contact between the two bimetallic strips, the conductive sheet 14 protruding relative to the surface of the first bimetallic strip 12 can not only stabilize the contact position of the circuit conduction at the position of the conductive sheet 14, but also, for the first bimetallic strip 12 and the second bimetallic strip 13 that have been selected and installed, by controlling the thickness of the conductive sheet 14, the deformation of the two bimetallic strips when contact occurs can be accurately controlled.

[0047] Preferably, the bimetallic strip used in the miniature circuit breaker usually has the characteristic that the conductivity of the active layer is weaker than that of the passive layer. For the first bimetallic strip 12 and the second bimetallic strip 13 arranged side by side, in order to achieve that the first bimetallic strip 12 can contact the second bimetallic strip 13 after being deformed under the thermal effect of the load current, the layer structure of the first bimetallic strip 12 close to the second bimetallic strip 13 is the active layer, and the layer structure of the second bimetallic strip 13 close to the first bimetallic strip 12 is the passive layer. In order to optimize the electrical connection quality between the conductive strip 14 and the first bimetallic strip 12, so as to improve the performance stability of the electromagnetic coil 1, the conductive strip 14 is configured as a protruding structure integrally formed on the passive layer of the first bimetallic strip 12, and the protruding structure passes through the active layer through the hole on the active layer of the first bimetallic strip 12. When the thickness of the conductive strip 14 needs to be controlled, a protruding structure of suitable thickness is selected or grinding is performed on the basis of the original thickness.

[0048] Embodiment 6: This embodiment is further refined on the basis of embodiment 1: A more complete configuration is provided to further include an electromagnetic coil 1 connected to a third cable 15. In this solution, the third cable 15 is a cable for establishing a conductive relationship between the electromagnetic coil 1 and the second bimetallic strip 13. The third cable 15 is connected to one of the terminals of the electromagnetic coil 1, and the other terminal of the electromagnetic coil 1 is connected to a neutral line or a ground line in the distribution box. The moving contact 2 and the static contact 4 are connected in series to the live line to control the conductive state of the live line.

[0049] Embodiment 7: This embodiment is further refined on the basis of embodiment 1: It also includes a linkage device 3, which is used to realize the linkage between the bimetal component 6 and the handle operation module 22 of the miniature circuit breaker; The linkage is as follows: the bimetal component 6 pushes one end of the linkage device 3 to swing through the thermally deformed first bimetallic strip 12 or the second bimetallic strip 13, and the other end of the linkage device 3 swings synchronously and drives the handle operating module 22 to swing in the direction of achieving the tripping of the miniature circuit breaker.

[0050] The above scheme aims to provide a purely mechanical tripping scheme, which is used to realize that when the electromagnetic driver including the electromagnetic coil 1 cannot work normally, the linkage device 3 is used to drive the handle operating module 22 to operate, so as to realize the tripping of the miniature circuit breaker. Specifically, when the first bimetallic strip 12 produces a large deformation due to overload, it pushes one end of the linkage device 3 to swing, and the synchronous swing occurring at the other end of the linkage device 3 provides a driving force for the operation of the handle operating module 22, so that the handle operating module 22 swings in the direction of realizing the tripping of the miniature circuit breaker to cut off the circuit, so as to provide a guarantee for the miniature circuit breaker to perform the tripping action.

[0051] Embodiment 8: This embodiment is further refined on the basis of Embodiment 7: It also includes a component box 23, in which the first bimetallic strip 12 and the second bimetallic strip 13 are both installed; The linkage device 3 includes a swing rod rotatably connected to the component box 23, one end of the swing rod is embedded in the component box 23, and the end of the swing rod is located on the thermal deformation track of the first bimetallic strip 12 or the second bimetallic strip 13; the other end of the swing rod is used to connect with the handle operation module 22; When the linkage device 3 realizes the phase linkage, the rocker rod serves as a force-consuming lever.

[0052] The above provides a specific bimetal assembly 6, linkage device 3 structural form and matching form. In the above scheme, the assembly box 23 serves as the outer shell of the bimetal assembly 6, and the swing rod is rotatably connected to the assembly box 23. When the first bimetal 12 or the second bimetal 13 (due to the hysteresis of the deformation of the second bimetal 13 under fault conditions, the first bimetal 12 is preferably used) is deformed to push the swing rod to swing, the other end of the swing rod acts on the handle operating module 22 to drive the handle operating module 22 to perform the action of realizing the miniature circuit breaker tripping. The swing rod is set as a laborious lever, that is, relative to the connection point of the swing rod on the assembly box 23, the force arm on the action side of the first bimetal 12 or the second bimetal 13 is shorter than the force arm on the action side of the handle operating module 22, relative to the deformation of the corresponding bimetal, it is used to amplify the action stroke of the swing rod on the handle operating module 22.

[0053] Embodiment 9: This embodiment provides a miniature circuit breaker on the basis of Embodiment 1, including a tripping drive unit, a moving contact 2 connected to the tripping drive unit, a stationary contact 4 fixed in the miniature circuit breaker, and a circuit main circuit cable, and also includes the miniature circuit breaker tripping mechanism described in Embodiment 1, the circuit main circuit cable includes a first cable 5 and a second cable 7, the first cable 5 is used as a cable between the stationary contact 4 and the miniature circuit breaker inlet terminal, and the miniature circuit breaker tripping mechanism is installed as follows: The second cable 7 serves as a cable between the moving contact 2 and one end of the first bimetallic strip 12, and also includes a fourth cable 16, which serves as a cable between the other end of the first bimetallic strip 12 and the output terminal of the miniature circuit breaker. The third cable 15 is used to realize the second bimetallic strip 13 and the electromagnetic coil 1 of the tripping drive unit in series.

[0054] The above scheme is: the first bimetallic strip 12 is connected in series to the main circuit of the miniature circuit breaker through the first cable 5, the static contact 4, the moving contact 2, and the second cable 7, and the second bimetallic strip 13 is electrically connected to the electromagnetic coil 1 of the tripping drive unit through the third cable 15. When the first bimetallic strip 12 and the second bimetallic strip 13 are connected to provide a driving current for the electromagnetic coil 1, the moving iron core of the tripping drive unit drives the moving contact 2 to separate from the static contact 4, so as to achieve the purpose of circuit cutting protection. This scheme is a technical scheme including the tripping mechanism.

[0055] Embodiment 10: This embodiment is further refined on the basis of Embodiment 9: It also includes a sensor unit, a control unit and a communication unit, wherein the sensor unit is used to collect one or more of the current, voltage, power, power factor and frequency parameters on the main circuit of the circuit, and transmit the detection result to the control unit; The control unit is used to determine whether to trigger the power-off protection action according to the detection result, and when it is determined that the power-off protection action is triggered, control the tripping drive unit to act so as to drive the moving contact 2 to move to a state separated from the static contact 4; The communication unit is used to perform one or more of the following actions: Transmitting the detection results of the sensor unit to the remote monitoring terminal; Transmitting the action signal of the tripping drive unit to the remote monitoring terminal; Receive control instructions from the remote monitoring end to the miniature circuit breaker, and transmit the control instructions to the control unit; The control instruction includes an action instruction and a built-in parameter of the miniature circuit breaker, wherein the action instruction is an instruction for controlling the miniature circuit breaker to trip, and the built-in parameter is a threshold parameter built into the miniature circuit breaker for determining whether to trigger a power-off protection action.

[0056] The above scheme aims to provide an intelligent miniature circuit breaker, specifically: the control unit determines whether to trigger the power-off protection action according to the detection signal of the sensor unit, and the communication unit is used to realize one or more of the line detection function, the line working state feedback function, the line remote control function, and the miniature circuit breaker working parameter remote adjustment function. Therefore, this scheme is an intelligent miniature circuit breaker including an electronic protection system.

[0057] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific embodiments of the present invention are limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, other embodiments obtained without departing from the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A miniature circuit breaker tripping mechanism, characterized in that: The bimetallic component (6) comprises a first bimetallic strip (12) and a second bimetallic strip (13), wherein the first bimetallic strip (12) and the second bimetallic strip (13) are both provided with a support plate (11) and a connecting seat (10); The first bimetallic strip (12) and the second bimetallic strip (13) are both: One end is fixed on the support plate (11), and the other end is slidably connected to the support plate (11) via a connecting seat (10); The first bimetallic strip (12) and the second bimetallic strip (13) both have the same thermal deformation direction; The two can be deformed such that: in a cold state, the two are separated from each other, and in a hot state, the two can be deformed such that the middle part of the first bimetallic strip (12) contacts the middle part of the second bimetallic strip (13); Both ends of the first bimetallic strip (12) are provided with connection terminals (8) or fourth cables (16) for connecting the first bimetallic strip (12) in series in the main circuit of the miniature circuit breaker circuit; The second bimetallic strip (13) is connected to a third cable (15) for connecting the second bimetallic strip (13) and the electromagnetic coil (1) in series.

2. The miniature circuit breaker tripping mechanism according to claim 1, characterized in that: It also comprises a component box (23), wherein two supporting plates (11) parallel to each other are arranged in the component box (23); The first bimetallic strip (12) and the second bimetallic strip (13) are respectively mounted on different support plates (11) and are located in a gap between the two support plates (11); Each support plate (11) has a strip hole (17) extending along the length direction of the support plate (11) at one end of the support plate (11), and a circular hole (18) at the other end of the support plate (11); the circular hole (18) is used to achieve fixed connection between the first bimetallic strip (12), the second bimetallic strip (13) and the support plate (11); and the strip hole (17) is used to achieve sliding connection between the first bimetallic strip (12), the second bimetallic strip (13) and the support plate (11).

3. The miniature circuit breaker tripping mechanism according to claim 2, characterized in that: The connecting seat (10) comprises a connecting screw (19), one end of which is provided with two layers of clamping blocks (20), and each layer of clamping blocks (20) has a clamping block (20) on each side of a pair of opposite sides of the connecting screw (19); In the axial direction of the connecting screw rod (19), the two layers of clamping blocks (20) are in a mutually facing stacked relationship, and a clamping groove (21) is formed between the two layers of clamping blocks (20), and the width of the clamping groove (21) satisfies: one end of the connecting screw rod (19) having the clamping block (20) is embedded in the strip-shaped hole (17), and the end of the connecting screw rod (19) is clamped and connected to the support plate (11) through the clamping groove (21); The width of the card block (20) satisfies the following conditions: the width of the card block (20) is smaller than the width of the strip-shaped hole (17); The other end of the connecting screw rod (19) is provided with an external thread, and the connecting seat (10) is threadedly connected to a nut on the external thread to lock the first bimetallic strip (12) and the second bimetallic strip (13) between the nut and the clamping block (20).

4. The miniature circuit breaker tripping mechanism according to claim 2, characterized in that: One end of the first bimetallic strip (12) that is slidably connected to the support plate (11) is provided with a spiral cable (9); the wiring terminal (8) is fixed to the component box (23); one end of the spiral cable (9) is connected to the first bimetallic strip (12); and the other end of the spiral cable (9) is connected to the wiring terminal (8).

5. The miniature circuit breaker tripping mechanism according to claim 1, characterized in that: It also includes a conductive sheet (14) arranged in the middle of the first bimetallic sheet (12), the conductive sheet (14) being located on a side of the first bimetallic sheet (12) close to the second bimetallic sheet (13), and the conductive sheet (14) protruding relative to the surface of the first bimetallic sheet (12).

6. The miniature circuit breaker tripping mechanism according to any one of claims 1 to 5, characterized in that: It also includes an electromagnetic coil (1) connected to a third cable (15).

7. The miniature circuit breaker tripping mechanism according to any one of claims 1 to 5, characterized in that: It also includes a linkage device (3), wherein the linkage device (3) is used to realize linkage between the bimetal component (6) and the handle operating module (22) of the miniature circuit breaker; The linkage is as follows: the bimetal component (6) drives one end of the linkage device (3) to swing through the thermally deformed first bimetallic sheet (12) or the second bimetallic sheet (13), and the other end of the linkage device (3) swings synchronously and drives the handle operating module (22) to swing in a direction to achieve the tripping of the miniature circuit breaker.

8. The miniature circuit breaker tripping mechanism according to claim 7, characterized in that: It also includes a component box (23), wherein the first bimetallic strip (12) and the second bimetallic strip (13) are both installed in the component box (23); The linkage device (3) comprises a swing rod rotatably connected to the component box (23), one end of the swing rod being embedded in the component box (23), and the end of the swing rod being located on a thermal deformation track of the first bimetallic strip (12) or the second bimetallic strip (13); the other end of the swing rod being used to be connected to the handle operation module (22); When the linkage device (3) realizes the phase linkage, the rocker rod serves as a force-consuming lever.

9. A miniature circuit breaker, comprising a tripping drive unit, a moving contact (2) connected to the tripping drive unit, a stationary contact (4) fixed in the miniature circuit breaker, and a main circuit cable, characterized in that: It also comprises the miniature circuit breaker tripping mechanism according to any one of claims 1 to 8, the main circuit cable comprises a first cable (5) and a second cable (7), the first cable (5) serves as a cable between the static contact (4) and the miniature circuit breaker inlet terminal, and the miniature circuit breaker tripping mechanism is installed as follows: The second cable (7) serves as a cable between the moving contact (2) and one end of the first bimetallic strip (12), and further comprises a fourth cable (16). The fourth cable (16) serves as a cable between the other end of the first bimetallic strip (12) and an outlet terminal of the miniature circuit breaker. The third cable (15) is used to connect the second bimetallic strip (13) in series with the electromagnetic coil (1) of the tripping drive unit.

10. The miniature circuit breaker according to claim 9, characterized in that: It also includes a sensor unit, a control unit and a communication unit, wherein the sensor unit is used to collect one or more of the current, voltage, power, power factor and frequency parameters on the main circuit of the circuit, and transmit the detection result to the control unit; The control unit is used to determine whether to trigger a power-off protection action based on the detection result, and when it is determined that the power-off protection action is triggered, control the trip drive unit to act so as to drive the moving contact (2) to move to a state where it is separated from the stationary contact (4); The communication unit is used to perform one or more of the following actions: Transmitting the detection results of the sensor unit to the remote monitoring terminal; Transmitting the action signal of the tripping drive unit to the remote monitoring terminal; Receive control instructions from the remote monitoring end to the miniature circuit breaker, and transmit the control instructions to the control unit; The control instruction includes an action instruction and a built-in parameter of the miniature circuit breaker, wherein the action instruction is an instruction for controlling the miniature circuit breaker to trip, and the built-in parameter is a threshold parameter built into the miniature circuit breaker for determining whether to trigger a power-off protection action.

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