Built-in backup protection tripping device of circuit breaker

Abstract

The invention discloses a built-in backup protection tripping device of a circuit breaker, and belongs to the technical field of circuit breakers. Comprising a magnetic steel unit group and an actuating mechanism, the magnetic steel unit group is composed of a fixed first magnetic steel group and a slidable second magnetic steel group, and an induced current is generated when the magnetic steel unit group is electrified to drive the second magnetic steel group to move transversely; the action mechanism comprises a push plate, a push plate spring, an inclined plane guide block and a push rod, when short circuit occurs, the electromagnetic driving force overcomes the spring force and drives the push plate to move transversely, the transverse movement of the push plate is converted into the vertical movement of the push rod through the inclined plane guide block, and a tripping rod of the circuit breaker is pushed to rotate to realize tripping. According to the device, a non-excitation type and passive response type backup tripping mechanism is constructed by innovatively adopting an induction magnetic steel group and an inclined plane motion conversion mechanism, the technical defect of protection failure caused by electromagnetic interference of a traditional electromagnetic tripping device is fundamentally overcome, and the device is particularly suitable for the application field with extremely high requirements on safety and stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of circuit breakers, and particularly relates to a built-in backup protection tripping device of a circuit breaker. BACKGROUND

[0002] The tripping unit is a moving execution component of the operating mechanism of the circuit breaker. When a short-circuit fault occurs in the circuit, the current transformer built in the circuit breaker first senses a transient large current signal and transmits the same to the controller for analysis and judgment. The controller then sends an execution instruction to the split excitation tripping device in the form of an electric signal. After receiving the signal, the split excitation tripping device converts electric energy into mechanical energy, pushes the tripping half shaft, and finally prompts the operating mechanism to complete the opening operation, thereby realizing the disconnection of the circuit. This protection mode has a mature structure and has been widely used.

[0003] However, the action of the split excitation tripping device depends on the instruction sent by the controller, and the controller signal is derived from the sensing of the current transformer. Since the controller is internally composed of electronic elements, it is easily affected by electromagnetic interference. Once a misjudgment occurs, the entire protection chain will fail, causing the circuit breaker to lose the key disconnection capability and further causing serious safety hazards.

[0004] In view of this, it is necessary to improve the existing short-circuit protection mode which only relies on the single path of “current transformer-controller-split excitation tripping device”, and to provide a backup protection tripping mechanism independent of the electronic control circuit. When the main protection system fails due to electromagnetic interference or other reasons, the backup protection tripping mechanism can directly respond to the short-circuit current and reliably trigger tripping, thereby enhancing the safety redundancy of the circuit breaker. SUMMARY

[0005] The application is proposed to solve the above problems in the prior art, and provides a built-in backup protection tripping device of a circuit breaker which can directly transmit a short-circuit signal to an operating mechanism to cut off the power supply of the circuit without a controller.

[0006] The application can be implemented by the following technical scheme: A built-in backup protection tripping device of a circuit breaker, comprising: at least one magnetic steel unit group, which is installed in an insulating base of the circuit breaker, wherein the insulating base has a receiving groove which is sunkenly arranged, an insulating plate is arranged on the receiving groove, the insulating plate and the receiving groove jointly form a receiving space, the magnetic steel unit group is arranged in the receiving space, and a top surface of the insulating plate is used to install a static contact of the circuit breaker; the magnetic steel unit group is composed of a first magnetic steel group which is fixedly arranged and a second magnetic steel group which is laterally slidable, and an induced current is generated between the two groups when the circuit breaker is powered on and an electromagnetic driving force for lateral movement of the second magnetic steel group is provided; an operating mechanism, which is arranged in the insulating base and comprises: a push plate assembly connected with the second magnet group and moving synchronously with the second magnet group; a slope guide block arranged on the push plate assembly and having a slope guide surface; a push rod having one end abutting against the slope guide block and the other end used for linkage with a trip lever of a circuit breaker; when the circuit breaker is short-circuited, the second magnet group is driven by an electromagnetic driving force generated by an induced current to move laterally synchronously with the push plate assembly and the slope guide block, the lateral movement of the push plate is converted into vertical displacement of the push rod through the slope guide surface, and the push rod pushes the trip lever to rotate to trigger a tripping action.

[0007] As a further improvement of the present application, the insulating base is provided with a plurality of accommodating grooves for mounting the magnet unit groups, and adjacent accommodating grooves are separated by partitions, each partition is provided with an opening located on the same straight line, the push plate assembly penetrates through each opening and simultaneously connects the magnet unit groups in each accommodating groove.

[0008] As a further improvement of the present application, the push plate assembly includes a push plate and a push plate spring, the push plate is connected with the second magnet group, the push plate spring is used to apply a reset pre-tightening force to the push plate, and the slope guide block is arranged on the push plate.

[0009] As a further improvement of the present application, the first magnet group is arranged in a semi-enclosed structure and has an accommodating gap, and the second magnet group is movably arranged at the accommodating gap.

[0010] As a further improvement of the present application, the second magnet group has a separation position and a closed position, wherein, when the second magnet group is in the separation position, a gap is left between one end of the second magnet group and the first magnet group, and the magnetic circuit is in an open state; when the second magnet group is in the closed position, the second magnet group is moved to abut against the end surface of the first magnet group under the electromagnetic driving force, forming a closed magnetic circuit.

[0011] As a further improvement of the present application, the second magnet group is provided with a connecting plate, the side of the connecting plate has a connecting protrusion, the connecting protrusion penetrates through the push plate and is used to hang the push plate spring.

[0012] As a further improvement of the present application, the push plate spring is coaxially arranged with the push plate, when the second magnet group moves laterally, the pulling force provided by the push plate spring is coaxial with the electromagnetic driving force and has an opposite direction.

[0013] As a further improvement of the present application, the second magnetic steel group is coaxially arranged with the push plate, and the push rod is perpendicular to the push plate.

[0014] As a further improvement of the present application, the push rod is provided with a push rod spring for providing a downward pressure, and the end of the push rod is always close to the inclined guide surface of the inclined guide block as the push plate moves.

[0015] As a further improvement of the present application, the top surface of the insulating plate is also used for mounting a starting point and an arc starting piece.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] 1. Strong anti-electromagnetic interference capability to ensure reliable tripping in extreme environments The device adopts an inductive magnetic steel group structure, and the short-circuit current generates eddy current in the magnetic steel to drive tripping, instead of relying on an external excitation coil, thereby fundamentally avoiding the misoperation or refusal of the traditional electromagnetic tripper caused by external strong electromagnetic field interference, and the device is especially suitable for complex electromagnetic environments such as military industry, ships, and radar systems, and can ensure stable triggering of backup protection when the main protection fails.

[0018] 2. Double insurance protection mechanism to improve overall system safety As a backup protection device independent of the main tripping system, the device can automatically start and complete the tripping action when the traditional electromagnetic tripper fails due to aging, interference, or failure, forming a double-redundancy mechanism of “main protection + backup protection”, and significantly enhancing the safety and reliability of the circuit breaker in critical application scenarios.

[0019] 3. Magnetic circuit dynamic control design to achieve efficient and rapid response The first magnetic steel group and the second magnetic steel group form a “separation → closing” variable magnetic circuit structure. When normal, the magnetic circuit is open to inhibit misoperation; when short-circuited, the magnetic circuit is closed, the magnetic resistance is reduced, the magnetic energy is concentrated, and positive feedback is formed to accelerate response. This design improves the electromagnetic drive efficiency and action speed, and ensures rapid tripping in the initial stage of fault current rise.

[0020] 4. Precise mechanical transmission structure to ensure action consistency and stability The inclined guide block accurately converts horizontal motion into vertical thrust, the push rod spring ensures no gap in contact, the push plate spring is coaxially reset, and the components cooperate to form a direct-acting, low-loss transmission path. The entire mechanism has no looseness or jamming, has high action repeatability, and is suitable for high-reliability systems with strict requirements for protection consistency.

[0021] 5. Highly integrated and modular design to optimize space utilization and assembly efficiency The magnet unit is embedded in the recessed cavity of the insulating base and covered with an insulating plate to form a closed cavity. This achieves both electrical isolation and structural protection, and integrates functional components such as terminals, stationary contacts, and arc striking plates on its top surface. This greatly saves space, improves the overall compactness and manufacturability of the circuit breaker, and facilitates mass production and maintenance. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the backup protection tripping device of the circuit breaker of the present invention; Figure 2 This is a schematic diagram showing the positional relationship between the first magnet group and the second magnet group of the present invention; Figure 3 This is a schematic diagram of the structure of the circuit breaker insulation base after the wiring terminals, arc-starting plates, and stationary contacts are installed; Figure 4 This is a schematic diagram showing the installation position of the backup protection tripping device of the present invention within the insulating base; Figure 5 This is a schematic diagram showing the positional relationship between the push rod, push block, and circuit breaker tripping rod of the present invention.

[0023] In the diagram, 100 is the first magnet group; 110 is the second magnet group; 111 is the connecting plate; 1111 is the connecting protrusion; 120 is the push plate; 121 is the push plate spring; 130 is the inclined guide block; 131 is the inclined guide surface; 140 is the push rod; 141 is the push block; and 142 is the push rod spring. 200 Circuit breaker; 210 Tripping rod; 220 Insulating base; 221 Receiving groove; 222 Opening; 230 Insulating plate; 240 Terminal block; 250 Arc ignition piece; 251 Stationary contact. Detailed Implementation

[0024] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0025] like Figures 1-5 As shown, the present invention provides a built-in backup protection tripping device for a circuit breaker, comprising: At least one magnet unit group is installed in the insulating base 220 of the circuit breaker 200. The insulating base 220 has a recessed receiving groove 221. An insulating plate 230 is covered on the receiving groove 221. The insulating plate 230 and the receiving groove 221 enclose a closed space. The magnet unit group is disposed in the closed space. The top surface of the insulating plate 230 is used to install the stationary contact 251 of the circuit breaker. The magnetic steel unit group is composed of the fixed first magnetic steel group 100 and the second magnetic steel group 110 which can slide laterally, both of which are stacked by multiple magnetic steel sheets, and the induced current is generated between the two when the circuit breaker 200 is powered on, and the electromagnetic driving force for the lateral movement of the second magnetic steel group 110 is provided; The action mechanism comprises: The push plate 120 is connected with the push plate spring 121, and the push plate spring 121 is used to apply a reset pre-tightening force to the push plate 120; The inclined surface guide block 130 is arranged on the push plate 120 and has an inclined guide surface 131; The push rod 140 is abutted with the inclined surface guide block 130 at one end and is provided with the push block 141 for pushing the trip lever 210 of the circuit breaker 200 to rotate, and when the push rod 140 is lifted upward, the push block 141 can push the trip lever 210 of the circuit breaker 200 to rotate, thereby achieving the tripping purpose of the circuit breaker 200.

[0026] Specifically, the action principle of the backup protection tripping device is described as follows: Firstly, when the circuit breaker 200 is powered on, the induced current is generated between the first magnetic steel group 100 and the second magnetic steel group 110, and the electromagnetic driving force for the lateral movement of the second magnetic steel group 110 is provided; Under the normal load current, the induced current between the first magnetic steel group 100 and the second magnetic steel group 110 is small, and the electromagnetic driving force generated is insufficient to overcome the reset pre-tightening force applied by the push plate spring 121, so the second magnetic steel group 110 remains in the initial position (separation position), and the entire tripping mechanism is in the standby state; When the line has a short-circuit fault, the main circuit current rises sharply, which causes the magnetic field intensity between the first magnetic steel group 100 and the second magnetic steel group 110 to rapidly increase, and the electromagnetic driving force generated rapidly increases, and when the electromagnetic driving force exceeds the pre-tightening force of the push plate spring 121, the second magnetic steel group 110 starts to slide along the lateral direction to the first magnetic steel group 100, and the push plate 120 connected therewith moves synchronously; With the lateral movement of the push plate 120, the inclined surface guide block 130 pushes the push rod 140 to rise in the vertical direction (i.e. the "lateral→vertical" motion conversion is realized), the push block 141 is lifted, and the trip lever 210 is pushed to rotate, thereby releasing the operating mechanism of the circuit breaker 200 to separate the moving and static contacts 251, and the fault current is cut off (it should be noted that the structure related to the rotation of the trip lever 210 of the circuit breaker 200 to release the operating mechanism to separate the moving and static contacts 251 is the prior art, and therefore the structure is not described in detail); After troubleshooting, the short-circuit current disappears, the electromagnetic driving force returns to zero, the push plate spring 121 pulls the push plate 120 and the second magnetic steel group 110 back to the original position, the device automatically resets, and returns to the waiting trigger state, preparing for the next protection action.

[0027] It is worth mentioning that the backup protection tripping device provided by the embodiment is of an embedded structure. This embedded installation method has at least the following advantages: 1. High integration and reliable protection are achieved. By embedding the entire device (the magnetic steel unit group and the action mechanism) in the closed space of the insulating base of the circuit breaker, the backup protection function is integrated with the body of the circuit breaker, which greatly saves the installation space, maintains the compactness of the product, and provides a physical barrier for the precise mechanism against dust, moisture, and arc influence, thereby significantly improving the long-term environmental tolerance and insulation safety of the device.

[0028] 2. A fast, direct, and anti-interference pure mechanical protection is provided. The design enables the magnetic steel unit to be in close contact with the main conducting loop, directly sensing the magnetic field generated by the short-circuit current, and triggering tripping through a pure electromagnetic-mechanical transmission mechanism (without any electronic controller and signal conversion). This principle fundamentally eliminates the risk of false judgment or failure of the electronic control system caused by electromagnetic interference, forming an independent, fast, and extremely reliable hard-wire backup protection path, which greatly enhances the safety redundancy of the circuit breaker.

[0029] Further, since the magnetic steel unit group is embedded in the accommodating groove 221, and the depth of the accommodating groove 221 matches the height of the magnetic steel unit group, the outer surface of the magnetic steel unit group is basically flush with or slightly lower than the peripheral surface of the insulating base 220 after installation, thereby achieving a highly integrated and compact design, effectively utilizing the internal space of the circuit breaker 200, avoiding the problem of occupying additional volume by traditional external electromagnetic mechanisms, and being conducive to the miniaturization and modularization of the overall circuit breaker 200.

[0030] This embedded structure also limits and supports the magnetic steel unit group by the side wall of the installation cavity, significantly improving its mechanical stability and anti-vibration ability during the action process, preventing displacement, loosening, or deflection caused by impact or repeated action, and ensuring the reliability of each tripping action.

[0031] In addition, the closed space formed by the insulating plate 230 and the installation cavity not only provides physical protection for the magnetic steel unit group, but also effectively constructs a shielded working space that is resistant to electromagnetic interference, blocking the path of external strong electromagnetic fields (such as lightning pulses, radio frequency interference, frequency converter harmonics, etc.) directly coupling to the inside of the magnetic steel, avoiding the induction of additional eddy currents or interference magnetic fields in the magnetic steel by external electromagnetic noise, thereby preventing false actions or action delays caused by electromagnetic crosstalk, and significantly enhancing the anti-interference ability of the device to external electromagnetic fields.

[0032] Preferably, the top surface of the insulation plate 230 is used to carry the wiring terminal 240, the arc striking piece 250 and the static contact 251, when the circuit breaker 200 is tripped, the moving contact of the circuit breaker 200 is quickly separated from the static contact 251 by the operating mechanism, and the reliable breaking of the main circuit is realized.

[0033] The design has the advantages of significant integration and functional synergy: the insulation plate 230 not only realizes the closed protection of the magnetic unit, but also serves as a mounting base for the upper functional components, integrating the wiring terminal 240 (for external cable connection), the arc striking piece 250 (for guiding the electric arc into the arc extinguishing chamber), and the static contact 251 (forming a main contact pair with the moving contact) on its surface to form a multifunctional integrated structure platform. This layout not only saves internal space and optimizes the electrical path, but also improves the assembly efficiency and structural compactness of the circuit breaker 200.

[0034] In addition, it should be noted that in existing circuit breakers 200, electromagnetic trippers are often used for tripping, but electromagnetic trippers are prone to electromagnetic interference, which can cause abnormal tripping. To solve this problem, the present embodiment additionally provides a backup protection tripping device as a secondary tripping protection mechanism to ensure that the entire circuit breaker 200 can effectively trip in various use scenarios. This design has at least the following advantages: 1. Strong anti-electromagnetic interference capability: The driving mechanism does not rely on external magnetic field control, avoiding external electromagnetic signal interference with the tripping action, ensuring reliable operation in complex electromagnetic environments (such as military fields) and eliminating misoperation and refusal to operate; 2. High reliability backup protection: The main protection can still trigger tripping independently when it fails, forming a "double insurance" mechanism and significantly improving the overall safety of the circuit breaker 200; In addition, the present embodiment uses the design of the inclined guide block 130 to efficiently convert the lateral movement of the push plate 120 into vertical movement of the push rod 140, thereby driving the tripping action. This structure forms a straight driving mode for the entire action mechanism, with a clear and precise mechanical transmission path; And the components are tightly matched with no transmission gap, effectively avoiding the risk of action delay or failure, ensuring that the tripping can be triggered quickly, reliably and consistently every time a short-circuit fault occurs, significantly improving the stability and response accuracy of the protection action.

[0035] Overall, the embodiment innovatively uses the inductive magnetic steel group + inclined surface motion conversion mechanism to construct a non-excitation type, passive response type backup trip mechanism, which fundamentally overcomes the technical defects of the traditional electromagnetic trip due to electromagnetic interference leading to protection failure. It not only has the advantages of rapid response, reliable structure, strong anti-interference ability, etc., but also can be used as a redundant backup for the main protection, and can still ensure the effective tripping of the circuit breaker 200 under extreme working conditions. It is particularly suitable for application fields with extremely high safety and stability requirements, such as the military field, and has significant technical progress significance and application value.

[0036] Preferably, the insulating base 220 is provided with a plurality of accommodating grooves 221 for mounting the magnetic steel unit groups, and the adjacent accommodating grooves 221 are separated by partitions. Each partition is processed with an opening 222, and these openings 222 are accurately arranged on the same straight line to form a continuous guide channel. The push plate assembly penetrates all these openings 222 in sequence, thereby connecting the second magnetic steel groups (i.e. movable parts) of the magnetic steel unit groups distributed in each accommodating groove 221.

[0037] By arranging multiple magnetic steel unit groups in parallel and rigidly connecting their movable parts through a penetrating push plate 120, the electromagnetic driving force generated by multiple units can be converged when a short circuit occurs, and act on a push plate 120, thereby significantly increasing the total driving force and ensuring sufficient power and high reliability of the tripping action. Secondly, the mechanical rigid linkage ensures that the second magnetic steel groups 110 of all magnetic steel unit groups must move synchronously, completely avoiding the possibility of jamming or action failure caused by asynchronous action of individual units, greatly improving the consistency and stability of the action. Finally, the partitions physically isolate each unit, effectively preventing magnetic and mechanical interference between them. The openings 222 on the partitions also serve as guides and supports for the push plate 120, ensuring that the push plate 120 always moves along the predetermined straight line trajectory, making the entire device more compact, stable and precise in action.

[0038] Preferably, the first magnetic steel group 100 is arranged in a half-enclosed structure with an accommodating gap, and the second magnetic steel group 110 is movably arranged in the accommodating gap. This structure not only realizes precise guidance and positioning of the second magnetic steel group 110, but more importantly, enables the second magnetic steel group 110 to have two distinct working positions - the separated position and the closed position. When the second magnetic steel group 110 is in the separated position, a gap is left between one end of the second magnetic steel group 110 and the first magnetic steel group 100, and the magnetic circuit is in an open state. When the second magnetic steel group 110 is in the closed position, it is moved to the end face of the first magnetic steel group 100 under the electromagnetic driving force, forming a closed magnetic circuit.

[0039] The fundamental purpose of this design is to achieve dynamic control of the magnetic circuit state, so that the device has the intelligent characteristics of "stable standby in normal state and rapid response in fault state".

[0040] 1. Separation position: guarantee the stability of normal operation When the circuit breaker 200 is normally powered and there is no short circuit fault, the main circuit current is small. At this time, only a weak induced current and electromagnetic force is generated between the first magnetic steel group 100 and the second magnetic steel group 110, the second magnetic steel group 110 stays in the separation position (i.e. the initial position), leaving an air gap between the end face of the first magnetic steel group 100, and the magnetic circuit is in an open state; In the open state, the magnetic resistance is maximum, and the magnetic flux is difficult to form a closed loop, so there will be no significant magnetic attraction or misoperation tendency, thus preventing misoperation caused by normal load fluctuations, slight current changes or external electromagnetic interference, and ensuring stable system operation.

[0041] 2. Closed position: achieve efficient response in fault state When a short circuit fault occurs, the current rises sharply, and the strong current generates a high-strength alternating magnetic field around the first magnetic steel group 100, which induces strong eddy currents in the second magnetic steel group 110. The eddy currents and the magnetic field interact to generate a large enough electromagnetic driving force, which pushes the second magnetic steel group 110 to overcome the spring pre-tightening force and slide towards the first magnetic steel group 100 until the end face is attached, entering the closed position; At this time, the two magnetic steel groups form a complete magnetic circuit, the magnetic resistance is significantly reduced, the magnetic flux density is rapidly concentrated and enhanced, forming a closed magnetic circuit. After the magnetic circuit is closed, the electromagnetic energy utilization rate is greatly improved, further strengthening the driving effect and forming a "positive feedback mechanism" to accelerate the tripping response.

[0042] Overall, by designing the conversion of the second magnetic steel group 110 between the separation position and the closed position, dynamic control of the magnetic circuit state is achieved, significantly improving the reliability and response performance of the tripping device. This "from open to closed" conversion mechanism not only realizes efficient energy utilization and positive feedback acceleration response under fault current, but also endows the device with excellent anti-interference ability, especially suitable for key power distribution systems in strong electromagnetic environments such as military and ships, ensuring that the backup protection function can still be independently and reliably executed when the main protection fails. It has the comprehensive advantages of simple structure, accurate action and high safety redundancy.

[0043] Preferably, the second magnetic steel group 110 is provided with a connecting plate 111, the side of the connecting plate 111 is provided with a connecting lug 1111, the connecting lug 1111 penetrates through the push plate 120 and is used to hang the push plate spring 121, thereby realizing the connection between the second magnetic steel group 110 and the push plate 120, so that the push plate 120 can move synchronously with the second magnetic steel group 110; Wherein, since the connecting plate 111 is embedded in the second magnetic steel group 110, the structure is compact, does not occupy additional space, and enhances the overall integration. The scheme simplifies the assembly process, improves the reliability of the spring connection, ensures that the device can maintain consistent protection characteristics after long-term operation or after experiencing multiple tripping, and significantly enhances the durability and safety of the backup protection mechanism of the circuit breaker 200.

[0044] Further, the push plate spring 121 is coaxially arranged with the push plate 120. When the second magnetic steel group 110 moves laterally, the push plate spring 121 provides a pulling force coaxial and opposite in direction to the electromagnetic driving force. This design makes the reset spring force and the electromagnetic driving force always maintain a good mechanical relationship in terms of force line consistency and centration during movement. In addition, by adjusting the pre-tightening force of the push plate spring 121, the resistance that needs to be overcome by the second magnetic steel group 110 when moving from the separation position to the closed position can be directly changed, thereby accurately setting the short-circuit current threshold value for triggering the tripping action. When the short-circuit current is greater than the spring pre-tightening force, the electromagnetic driving force generated between the magnetic steel groups, the mechanism is started and the tripping is completed.

[0045] Therefore, the size of the spring pre-tightening force realizes the adjustability and configurability of the tripping current value, without the need to change the magnetic circuit structure or core components. By adjusting the spring pre-tightening force, different rated current levels or protection requirements of the circuit breaker 200 application scenarios can be adapted.

[0046] For example, in situations requiring higher short-circuit protection sensitivity, the pre-tightening force can be reduced to lower the action threshold; while in environments requiring higher resistance to transient surges or misoperation, the pre-tightening force can be appropriately increased to improve the anti-interference ability.

[0047] This mechanical adjustment method is simple in structure, stable and reliable, and does not require an electronic control unit. It is particularly suitable for passive, high-safety-level backup protection systems, enhancing the versatility and engineering applicability of the device.

[0048] Preferably, the second magnetic steel group 110 is coaxially arranged with the push plate 120, ensuring that the two remain synchronized and stable in lateral movement during operation. Meanwhile, the push rod 140 is arranged perpendicular to the push plate 120, with its axis orthogonal to the movement direction of the push plate 120, forming a clear force transmission path.

[0049] Wherein, the push rod 140 is provided with a push rod spring 142 for applying a downward pressing force to the push rod 140, so that the end of the push rod 140 is always tightly attached to the inclined guide surface 131 of the inclined guide block 130, achieving dynamic following.

[0050] It is worth mentioning that the push rod 140 is perpendicular to the layout of the push plate 120, combined with the continuous downward pressure of the push rod spring 142, to ensure that the push rod 140 can always adhere to the inclined surface during the lateral movement of the push plate 120, realize the gapless and uninterrupted motion conversion, accurately convert the lateral displacement into the vertical direction of the tripping pushing force, and prevent the push rod 140 from being separated or jumping from the inclined surface, effectively avoiding action failure or response delay.

[0051] The design not only improves the stability and response speed of transmission, but also enhances the adaptability of the device in complex environments, and is particularly suitable for high safety level electrical systems with high consistency requirements for protection action.

[0052] The technical means disclosed in the technical scheme of the present application is not limited to the technical means disclosed in the above technical means, but also includes the technical scheme composed of any combination of the above technical features. The above is the specific embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, a number of improvements and refinements can be made, which are also considered as the protection scope of the present application.

[0053] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), if the certain posture changes, the directional indications also change accordingly.

[0054] In addition, the description such as "first", "second", "one" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited. The terms "connection", "fixation" and the like should be understood broadly, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0055] The technical solutions among various embodiments of the present application can be combined with each other, but must be based on that a person skilled in the art can realize, when the combination of the technical solutions appears contradictory or cannot be realized, it should be considered that the combination of the technical solutions does not exist, and is not within the protection scope required by the present application.

[0056] The specific embodiments described herein are merely illustrative of the principles of this application. Numerous modifications or adaptations will be readily apparent to those skilled in the art of the present application without departing from the spirit of the present application or the scope of the claims set forth below.

Claims

1. An internal backup protection trip device for a circuit breaker, comprising: The application relates to a circuit breaker with a magnetic steel unit group. The magnetic steel unit group is composed of a fixed first magnetic steel group and a laterally-slidable second magnetic steel group, and an induced current is generated between the two groups when the circuit breaker is powered, and the second magnetic steel group is provided with an electromagnetic driving force for lateral movement. The action mechanism is arranged on the insulating base and comprises: A push plate assembly is connected with the second magnetic steel group and is synchronously moved with the second magnetic steel group. An inclined guide block is arranged on the push plate assembly and has an inclined guide surface. A push rod is in abutment with one end of the inclined guide block and is used for linkage connection with a trip lever of the circuit breaker. When the circuit breaker is short-circuited, the second magnetic steel group is synchronously moved laterally by the electromagnetic driving force generated by the induced current, the lateral movement of the push plate is converted into vertical displacement of the push rod through the inclined guide surface of the inclined guide block, and the push rod pushes the trip lever to rotate to trigger a tripping action. The insulating base is provided with a plurality of accommodating grooves for mounting the magnetic steel unit group, and the accommodating grooves are separated by partitions.

2. A built-in backup protection tripping device for a circuit breaker according to claim 1, characterized in that, The push plate assembly comprises a push plate and a push plate spring.

3. A built-in backup protection tripping device for a circuit breaker according to claim 1, characterized in that, The first magnetic steel group is arranged in a half-enclosing structure and has an accommodating gap.

4. The built-in backup protection trip unit of claim 1, wherein, The second magnetic steel group has a separation position and a closed position.

5. The built-in backup protection trip unit of claim 1, wherein, When the second magnetic steel group is in the separation position, a gap is left between one end of the second magnetic steel group and the first magnetic steel group, and a magnetic circuit is in an open state. When the second magnetic steel group is in the closed position, the second magnetic steel group is moved to be in abutment with an end surface of the first magnetic steel group under the electromagnetic driving force, and a closed magnetic circuit is formed. The second magnetic steel group is provided with a connecting plate.

6. A built-in backup protection tripping device for a circuit breaker according to claim 3, characterized in that, The push plate spring is coaxial with the push plate.

7. A built-in backup protection tripping device for a circuit breaker according to claim 3, wherein The push rod is perpendicular to the push plate.

8. A built-in backup protection tripping device for a circuit breaker according to claim 3, characterized in that, The push rod is provided with a push rod spring for providing a downward pressure.

9. A built-in backup protection tripping device for a circuit breaker according to claim 3, characterized in that, The top surface of the insulating plate is also used for mounting a contact point and an arc striking piece.

10. The built-in backup protection trip unit of claim 1, wherein, ​

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