Molded case circuit breaker structure

Abstract

The invention discloses a molded case circuit breaker structure, which belongs to the technical field of power equipment and comprises a circuit breaker shell and an arc extinguishing system which is positioned in the circuit breaker shell, is used for segmenting and cooling an electric arc and is connected with a main circuit system; and the main circuit system is arranged below the arc extinguishing system, is used for realizing the on-off of a circuit, and is connected with the arc extinguishing system and the mechanism action system. The arc extinguishing system has the advantages that the arc extinguishing system comprises the metal grid pieces and the specially-designed gas generating piece, the grid pieces are densely arranged, and due to the fact that the length of each section of arc is shortened, the arc voltage is increased, and the stability of the arc is damaged, the arc can be extinguished more easily, the arc can be segmented more effectively, and the arc extinguishing efficiency is remarkably improved; the problem of arc reignition of a traditional arc extinguish chamber is solved, the arc is effectively segmented, the insulation distance between the arc extinguish chamber and the contact is increased through the Laval tube structure additionally arranged below the gas generation piece, and the voltage endurance capability is improved.

Description

Technical Field

[0001] This application relates to the field of power equipment technology, and in particular to a molded case circuit breaker structure. Background Technology

[0002] With the development and increasing complexity of power systems, the performance requirements for power equipment are also becoming more stringent. Among these, high-voltage molded case circuit breakers (MCCBs) are a common type of DC switch. As a crucial protective component in power systems, the primary function of a high-voltage MCB is to promptly disconnect the circuit in case of overload or short circuit, thereby protecting the circuit and equipment. However, existing high-voltage MCBs have some shortcomings, such as large size, insufficient breaking capacity, and poor tripping stability. These problems are particularly prominent in high-voltage DC (e.g., DC 1500V) and high-current (20kA) scenarios.

[0003] Specifically, existing high-voltage molded case circuit breakers often fail to adequately combine compact size with high performance in their design. For example, the arc extinguishing system design often fails to effectively divide and cool the arc, leading to arc reignition and insufficient breaking capacity. Inadequate opening distance and overtravel design in the main circuit system affect breaking reliability. Insufficient electromagnetic force in the thermomagnetic tripping system leads to maloperation, affecting tripping stability and accuracy. Furthermore, the linkage design and tripping structure of the mechanism's action system are not sufficiently optimized, resulting in high tripping friction resistance and slow tripping speed, affecting the circuit breaker's response speed and reliability. To address this, the present invention provides a molded case circuit breaker structure that, through innovative structural design, combines a compact size with an optimized internal structure, including an arc-extinguishing system, a main circuit system, a thermal-magnetic tripping protection system, and a mechanism actuation system. The design of this invention aims to improve the circuit breaker's breaking capacity, tripping stability, and response speed, making it more suitable for breaking and protecting DC high-voltage circuits, especially in DC 1500V high-current scenarios. Summary of the Invention

[0004] One of the objectives of this application is to provide a molded case circuit breaker structure to address the problems of insufficient breaking capacity, low arc extinguishing efficiency, and difficulty in effectively cutting off circuits in DC high voltage and high current scenarios.

[0005] To achieve the above objectives, the technical solution adopted in this application is: a molded case circuit breaker structure, comprising: Circuit breaker housing Arc extinguishing system, located inside the circuit breaker housing, is used to interrupt and cool the electric arc; The main circuit system, located on one side of the arc extinguishing system, is used to realize the switching of the circuit and is connected to the arc extinguishing system and the mechanism action system; The thermal-magnetic tripping system, located on one side of the mechanism's actuation system, is used to detect short-circuit and overload currents and trigger tripping action, and is connected to the mechanism's actuation system. The mechanism action system, located on one side of the thermal-magnetic trip system, is used to perform opening and closing actions and is connected to the main circuit system and the thermal-magnetic trip system; The arc extinguishing system is installed on the arc path of the moving and stationary contacts in the main circuit system to ensure that the arc can enter the arc extinguishing chamber for segmentation and cooling when it is broken. The upper part of the moving contact is provided with a horn-shaped structure, which is used to ignite the arc and enable the arc to transfer quickly.

[0006] The arc-extinguishing system, main circuit system, and thermomagnetic tripping system are arranged along a first direction, while the main circuit system and mechanism action system are arranged along a second direction. The length direction of the circuit breaker is the first direction, i.e., the x-direction, and the height direction of the circuit breaker is the second direction, i.e., the y-direction. The moving contact of the main circuit system is mechanically connected to the mechanism's actuation system to ensure the reliability of the tripping action. By mechanically connecting the moving contact of the main circuit system to the tripping latch of the mechanism's actuation system, long-delay protection is provided under overload conditions. This ensures that when tripping is required, the bimetallic strip can transmit a signal to the tripping latch, thereby triggering the tripping action. The moving contact can accurately separate from the stationary contact, avoiding tripping failure due to loose or unstable connections. This improves the circuit breaker's protection capability in emergency situations, enhances the overall reliability of the circuit breaker, avoids equipment damage and safety accidents caused by short circuits or overload currents, and improves the safety and reliability of the power system.

[0007] The bimetallic strip of the thermomagnetic tripping system is mechanically connected to the mechanism's action system to ensure that the tripping action can be triggered when a short circuit or overload current is detected. When the mechanism's action system receives a tripping command, it can act on the moving contact to ensure the timeliness and accuracy of the tripping action.

[0008] Preferably, the arc extinguishing system includes: The arc-extinguishing chamber contains at least 20 metal grids arranged densely. A gas-generating component is located inside the arc-extinguishing chamber. Below the gas-generating component is a Laval tube structure, which is fixedly connected to the inner wall of the arc-extinguishing chamber. Densely arranged metal grids are installed inside the arc-extinguishing chamber, arranged along a second direction. This allows the arc to be divided into multiple shorter arc segments. Because the length of each arc segment is shortened, the arc voltage increases, and the arc's stability is disrupted, making it easier to extinguish. This dense grid design, compared to the traditional arc-extinguishing chamber structure with fewer grids, can more effectively divide the arc, significantly improving arc-extinguishing efficiency. The gas-generating component, located inside the arc-extinguishing chamber, releases gas during the interruption process. This gas accelerates arc cooling, further reducing the arc's temperature and energy, allowing the arc to extinguish faster. This gas-generating component design, combined with the grids, makes the arc-extinguishing process more efficient, ensuring that the circuit breaker can safely and reliably disconnect the circuit in high-voltage, high-current DC scenarios. A Laval tube structure is installed below the gas-generating component, and this structure is fixedly connected to the inner wall of the arc-extinguishing chamber. This Laval tube structure increases the insulation distance between the arc-extinguishing chamber and the contacts. In high-voltage DC circuits, this increased insulation distance effectively improves the withstand voltage of the circuit breaker and prevents insulation breakdown caused by arc return or excessive electric field strength during breaking. Through this structural design, the circuit breaker's withstand voltage is increased to DC 1500V, meeting the requirements of DC high-voltage circuits and improving the system's safety and reliability.

[0009] Preferably, the main circuit system includes: Moving contact and stationary contact; The distance between the moving contact and the stationary contact is >30mm; the overtravel between the moving contact and the stationary contact is >2mm; the distance between the silver point of the moving contact and the arc-extinguishing chamber grid is >5mm when the moving contact is closed, and >10mm when the moving contact is open; the distance between the moving contact and the stationary contact is ≥36mm. This larger distance design can quickly lengthen the arc at the moment of disconnection, increase the arc cooling and extinguishing time, and thus significantly improve the reliability of disconnection. In high-voltage, high-current DC scenarios, the larger distance can effectively prevent arc reignition and ensure safe circuit disconnection. The distance between the silver point of the moving contact and the arc-extinguishing chamber grid is >5mm when the moving contact is closed, and >10mm when the moving contact is open. This precise distance design optimizes the arc movement path, allowing the arc to enter the arc-extinguishing chamber more smoothly during the disconnection process, further improving the arc extinguishing efficiency and disconnection capacity. The overtravel between the moving and stationary contacts is greater than 2mm. This design ensures sufficient contact pressure when the contacts are closed, guaranteeing good contact between them. Stable contact reduces contact resistance and heat generation during high current flow, improving contact lifespan and reliability. The contact spring 230 provides a final pressure of >10N, further enhancing contact stability during closure. This design not only ensures good contact when closed but also provides sufficient reaction force at the moment of breaking, helping to quickly pull the contacts apart, shortening breaking time, and increasing breaking speed.

[0010] Preferably, the thermomagnetic tripping system includes: The iron core is made of a stepped, highly permeable magnetic material; The bimetallic strip is mechanically connected to the iron core. The iron core is designed with a stepped high-permeability material, which significantly increases the magnetic flux density compared to traditional iron core structures. This design enables the thermomagnetic tripping system to generate a stronger electromagnetic force when it detects a short-circuit current, thereby triggering the tripping action more quickly and improving the tripping response speed and stability. The stepped iron core design also optimizes the magnetic field distribution, reduces magnetic circuit losses, further improves the electromagnetic performance of the system, and ensures stable operation under complex working conditions.

[0011] Preferably, the mechanism's actuation system includes: an upper connecting rod, a lower connecting rod, and a trip latch. The upper and lower connecting rods have an asymmetrical arc-shaped structure and are mechanically connected. The trip latch's contact surface is coated with a wear-resistant coating, and the trip latch is mechanically connected to the upper and lower connecting rods. During frequent opening and closing operations, the wear-resistant coating reduces wear on the contact surface, lowering the risk of failure due to poor contact or excessive wear. The mechanical connection between the trip latch and the upper connecting rod ensures the integrity and reliability of the mechanism's actuation system. During long-term operation, this connection method reduces loosening caused by vibration or impact. To prevent movement or damage and improve system stability, the upper and lower connecting rods adopt an asymmetrical arc structure. This design optimizes the motion path of the mechanism's action system and reduces frictional resistance during the opening process. By reducing friction, the connecting rods can move faster during the opening action, thus significantly improving the opening speed. This optimized design can increase the opening speed by 15%-20%, ensuring that the circuit breaker can quickly respond and disconnect the circuit when it detects a short circuit or overload current. The asymmetrical arc structure of the connecting rods also optimizes the lever ratio, further improving the efficiency of the mechanism's action system, enabling it to complete the opening action in a short time and enhancing the protection performance of the circuit breaker.

[0012] Preferably, the contact spring of the main circuit system provides a final pressure of >10N to ensure the contact stability when the moving contact and the stationary contact are closed. The contact spring providing a final pressure of >10N can ensure that the moving contact and the stationary contact have sufficient contact pressure when closed. This design makes the contact between the contacts tighter, thereby reducing contact resistance, reducing the heating phenomenon of the contacts when high current passes through, improving the service life and reliability of the contacts, and the stable contact pressure can also prevent the generation of arc due to poor contact, further improving the safety of the circuit breaker in the closed state.

[0013] Preferably, the circuit breaker housing is provided with a guide groove inside. The guide groove is used to guide the movement of the upper and lower connecting rods of the mechanism action system, ensuring the accuracy and stability of the opening and closing actions. During the breaking process, sufficient final pressure can help the contacts separate quickly and lengthen the arc in a short time, thereby improving the breaking efficiency. This design not only ensures the stability of the contacts when closed, but also provides strong support for the breaking process, enabling the circuit breaker to safely and reliably cut off the circuit under complex operating conditions of high voltage and high current.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: (1) Improved breaking and arc extinguishing performance: The arc extinguishing system includes metal grids and specially designed gas generating components. These grids are densely arranged. Due to the shortened length of each arc segment, the arc voltage increases, and the stability of the arc is destroyed, making it easier to extinguish. Compared with the traditional arc extinguishing chamber structure with fewer grids, this dense grid design can more effectively divide the arc, significantly improve the arc extinguishing efficiency, and solve the problem of arc reignition caused by insufficient grids in the traditional arc extinguishing chamber. It effectively divides the arc and improves the arc extinguishing efficiency. The Laval tube structure added below the gas generating component increases the insulation distance between the arc extinguishing chamber and the contacts, and improves the withstand voltage to DC1500V. This solves the problem of arc reignition caused by insufficient grids and simple gas generating component structure in the traditional arc extinguishing chamber, effectively improving arc division and cooling efficiency, thereby significantly improving the breaking capacity of the circuit breaker. This improvement solves the problems of insufficient breaking capacity and arc reignition in the existing technology, ensuring that the circuit breaker can safely and effectively cut off the circuit in DC high voltage and high current scenarios, and improving the reliability and safety of the system.

[0015] (2) Enhance the stability and response speed of the tripping system: This solution uses a stepped iron core made of high magnetic permeability material and a bimetallic strip with an adjustable bending coefficient, which improves the electromagnetic force and tripping stability of the thermomagnetic tripping system, increases the magnetic flux density, and enhances the electromagnetic force by 20%-30%, ensuring rapid tripping of short-circuit current and enhancing the stability of the action. By adjusting the bending coefficient of the bimetallic strip, the overload current and tripping time are accurately matched, effectively solving the problem of false tripping caused by insufficient electromagnetic force of the thermomagnetic tripping system.

[0016] (3) Improved efficiency of the mechanism action system: The mechanism action system in this solution reduces the tripping friction resistance and improves the tripping speed by optimizing the linkage structure and tripping design of the mechanism action system. The upper and lower linkages with asymmetrical arc structure are used to reduce the tripping friction resistance, and the tripping speed is increased by 15%-20% through lever ratio optimization. The tripping contact surface is coated with a wear-resistant coating to extend its service life. These improvements directly solve the problems of high tripping friction resistance and slow tripping speed, improve the response speed and reliability of the circuit breaker, and enable the circuit breaker to respond quickly when it detects short circuit or overload current, thereby improving the protection performance of the circuit breaker and the stability of the system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the arc extinguishing system and main circuit system of the present invention.

[0019] Figure 3 This is a schematic diagram of the opening distance and silver point position of the main circuit system of the present invention.

[0020] Figure 4 This is a schematic diagram of the overtravel of the main circuit system of the present invention.

[0021] Figure 5 This is a schematic diagram of the magnet core structure of the present invention.

[0022] Figure 6 This is a schematic diagram of the snap fastener structure of the present invention.

[0023] Figure 7 This is a schematic diagram of the lower connecting rod structure of the present invention.

[0024] Figure 8 This is a schematic diagram of the upper connecting rod structure of the present invention.

[0025] Figure 9 This is an exploded view of the internal structure of the present invention.

[0026] Figure 10 This is a schematic diagram of the gas-generating component structure of the present invention; Figure 11 This is an assembly diagram of the connecting rod of the present invention; Figure 12 This is a schematic diagram of the thermomagnetic tripping structure of the present invention; Figure 13 This is an exploded view of the arc-extinguishing chamber structure of the present invention.

[0027] In the diagram: 1. Circuit breaker housing; 160. Guide groove; 100. Arc extinguishing system; 110. Arc extinguishing chamber; 111. Metal grid; 120. Gas generating element; 121. Laval tube structure; 200. Main circuit system; 210. Moving contact; 220. Stationary contact; 230. Contact spring; 300. Thermomagnetic tripping system; 310. Magnetic core; 320. Bimetallic strip; 400. Mechanism action system; 410. Upper connecting rod; 420. Lower connecting rod; 430. Trip trip. Detailed Implementation

[0028] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0029] In the description of this application, it should be noted that the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., which indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of this application.

[0030] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0031] Example 1: One preferred embodiment of this application, such as Figures 1 to 2 As shown, a molded case circuit breaker structure includes: The circuit breaker housing 1 has a guide groove 160 inside, which guides the movement of the upper connecting rod 410 and the lower connecting rod 420 of the mechanism action system 400, ensuring the accuracy and stability of the opening and closing actions. An arc extinguishing system 100, located inside the circuit breaker housing 1, is used to divide and cool the electric arc and is connected to the main circuit system 200. The main circuit system 200 is used to realize the switching of the circuit. A thermal-magnetic tripping system 300, located on one side of the mechanism action system 400, is used to detect short-circuit and overload currents and trigger tripping actions, and is connected to the mechanism action system 400. The mechanism action system 400, located on one side of the thermal-magnetic tripping system 300, is used to perform opening and closing actions and is connected to both the main circuit system 200 and the thermal-magnetic tripping system 300. In this embodiment, the high-voltage molded case circuit breaker achieves efficient and reliable circuit breaking and protection by optimizing its internal structure and layout. The circuit breaker housing 1 is internally separated by a partition, which separates the arc extinguishing system 100, the main circuit system 200, the thermal-magnetic tripping system 300, and the mechanism action system 400 to ensure that each system operates independently without interference. Simultaneously, the handle moves within the guide groove 160 inside the housing, thereby guiding the upper connecting rod 410 and the lower connecting rod 420 of the mechanism action system to ensure the accuracy and stability of the opening and closing actions.

[0032] Under normal operating conditions, the moving contact 210 and stationary contact 220 of the main circuit system 200 are closed, and the circuit is conductive. When a short circuit or overload current occurs in the circuit, the bimetallic strip 320 of the thermomagnetic tripping system 300 is heated and bent, triggering the trip lever 430 of the trigger mechanism action system 400 to actuate, driving the upper connecting rod 410 and the lower connecting rod 420 to move along the guide groove 160, quickly pulling the moving contact 210 and stationary contact 220 apart, thus achieving circuit breaking.

[0033] During the tripping process, an electric arc is generated when the moving contact 210 separates from the stationary contact 220 and enters the arc-extinguishing chamber 110 of the arc-extinguishing system 100. The metal grid 111 inside the arc-extinguishing chamber divides the arc into multiple short arcs, while the gas-generating element 120 releases gas to cool the arc, ensuring rapid extinguishing and completing the tripping process. Through this design, the circuit breaker achieves efficient tripping, rapid tripping, and reliable arc extinguishing within a compact size, making it suitable for DC high-voltage, high-current scenarios.

[0034] Example 2: One preferred embodiment of this application, such as Figures 1 to 11As shown, a molded case circuit breaker structure is described. The moving contact 210 of the main circuit system 200 is mechanically connected to the mechanism actuation system 400 to ensure reliable tripping operation. The bimetallic strip 320 of the thermomagnetic tripping system 300 is mechanically connected to the mechanism actuation system 400 to ensure tripping operation is triggered when a short circuit or overload current is detected. The mechanical connection of the moving contact 210 to the mechanism actuation system 400 ensures that when a tripping command is triggered, the moving contact 210 can respond quickly, separating from the stationary contact 220, thereby cutting off the circuit. The stability of the connection makes the tripping action more reliable and reduces the risk of tripping failure due to connection failure. The bimetallic strip 320 of the thermomagnetic tripping system 300 is connected to the mechanism action system 400 through a mechanical connection. When a short circuit or overload current occurs in the circuit, the bimetallic strip 320 bends and deforms due to the heat generated by the current, thereby triggering the trip 430 to act. The action of the trip 430 further drives the mechanism action system 400 to perform the tripping operation and quickly cut off the circuit. This design ensures that when a short circuit or overload current is detected, the circuit breaker can respond quickly and perform the tripping action, effectively protecting the circuit and equipment from damage.

[0035] Example 3: One preferred embodiment of this application, such as Figures 1 to 11 As shown, a molded case circuit breaker structure is provided. The arc extinguishing system 100 is electrically connected to the moving contact 210 and stationary contact 220 of the main circuit system 200 to ensure that the arc can enter the arc extinguishing chamber 110 for segmentation and cooling when the circuit is broken. The arc extinguishing system 100 includes: an arc extinguishing chamber 110, which is provided with at least 20 metal grid plates 111 arranged densely; a gas generating element 120 located inside the arc extinguishing chamber 110, and a Laval tube structure 121 below the gas generating element 120, which is fixedly connected to the inner wall of the arc extinguishing chamber 110. When the moving contact 210 and stationary contact 220 of the main circuit system 200 are separated during the opening operation, the current in the circuit is cut off, and an arc is generated at the moment of contact separation. At this time, the arc extinguishing system 100 introduces the arc into the arc extinguishing chamber 110 through electrical connection, and the Laval tube structure 121 can accelerate the introduction of the arc into the arc extinguishing chamber 110.

[0036] The arc-extinguishing chamber 110 is equipped with densely arranged metal grids 111. These grids can divide the electric arc into multiple shorter arc segments. As the length of each arc segment is shortened, the arc voltage increases, and the stability of the arc is disrupted, making it easier to extinguish. This dense grid design significantly improves the arc segmentation efficiency and reduces the possibility of arc reignition. Simultaneously, the gas-generating element 120 located inside the arc-extinguishing chamber 110 releases gas during the breaking process. This gas accelerates the cooling of the arc, further reducing its temperature and energy, allowing it to extinguish more quickly. The Laval tube structure 121 below the gas-generating element 120 is fixedly connected to the inner wall of the arc-extinguishing chamber 110, increasing the insulation distance between the arc-extinguishing chamber and the contacts, improving the circuit breaker's withstand voltage capability, and ensuring safe and reliable circuit interruption in high-voltage scenarios such as DC 1500V. Through this optimized design, the arc-extinguishing system 100 can quickly and effectively divide and cool the arc at the moment of breaking, significantly improving arc-extinguishing efficiency and the circuit breaker's breaking capacity. Furthermore, the Laval tube structure 121 enhances insulation performance, improving the safety and reliability of the circuit breaker in high-voltage, high-current scenarios. This design is particularly suitable for complex operating conditions such as DC high voltage (e.g., DC 1500V) and high current (e.g., 20kA), ensuring the circuit breaker can safely and reliably interrupt the circuit and protect the safe operation of the power system.

[0037] Example 4: One preferred embodiment of this application, such as Figures 1 to 11 As shown, a molded case circuit breaker structure includes a main circuit system 200 comprising: a moving contact 210 and a stationary contact 220; the opening distance between the moving contact 210 and the stationary contact 220 is >30mm; the overtravel between the moving contact 210 and the stationary contact 220 is >2mm; when the moving contact 210 is closed, the vertical distance between the silver point and the plane of the grid of the arc-extinguishing chamber 110 is >5mm, and when the moving contact 210 is open, the distance between the silver point and the arc-extinguishing chamber 110 is >10mm; the contact spring 230 of the main circuit system 200 provides a final pressure of >10N to ensure the contact stability when the moving contact 210 and the stationary contact 220 are closed; in the closed state, the moving contact 210 and the stationary contact 220 are connected, and the contact spring provides a final pressure of >10N to ensure sufficient contact pressure when the moving contact and the stationary contact are closed, thereby ensuring good electrical contact, reducing contact resistance, reducing heat generation, and improving the service life and reliability of the contacts; When the moving contact 210 is closed, the distance between its silver point and the grid of the arc-extinguishing chamber 110 is >5mm. This distance design optimizes the arc's movement path, allowing the arc to smoothly enter the arc-extinguishing chamber 110 for segmentation and cooling during the opening process. Simultaneously, the overtravel between the moving contact 210 and the stationary contact 220 is >2mm. This overtravel design ensures sufficient contact pressure when the contacts are closed, maintaining good contact even after contact wear, further improving the contact stability and reliability. During tripping, the distance between the silver point of the moving contact 210 and the arc-extinguishing chamber 110 is >10mm. This distance design further optimizes the arc's movement path, ensuring that the arc can be effectively divided and cooled during the breaking process, thus improving arc-extinguishing efficiency. By optimizing the opening distance, overtravel, silver point position, and final pressure of the contact spring between the moving and stationary contacts, the high-voltage molded case circuit breaker in this embodiment exhibits higher reliability and stability during breaking and closing. These designs not only improve breaking capacity and reduce the risk of arc reignition but also enhance contact stability, extend contact life, and reduce maintenance costs. Furthermore, the optimized arc movement path and arc-extinguishing efficiency further enhance the safety and reliability of the circuit breaker in high-voltage, high-current scenarios.

[0038] Example 5: One preferred embodiment of this application, such as Figures 1 to 11 As shown, a molded case circuit breaker structure, wherein the thermal-magnetic tripping system 300 includes: Iron core 310, wherein the iron core 310 is a stepped high magnetic permeability material; Bimetallic strip 320, wherein the bimetallic strip 320 is mechanically connected to the iron core 310; In this embodiment, the thermal-magnetic tripping system 300 of the high-voltage molded case circuit breaker achieves rapid and accurate response to short-circuit and overload currents by employing a stepped high-permeability iron core 310 and an adjustable bending coefficient bimetallic strip 320. The stepped design of the iron core 310 increases the magnetic flux density and enhances the electromagnetic force, ensuring that the mechanism action system 400 can be quickly driven to complete the tripping when a short-circuit current passes through. At the same time, it optimizes the magnetic field distribution, reduces magnetic circuit losses, and improves system stability. This design significantly improves the response speed and stability of the thermal-magnetic tripping system, reduces the false tripping rate, and enhances the overall performance and safety of the circuit breaker under complex operating conditions.

[0039] Example 6: One preferred embodiment of this application, such as Figures 1 to 11As shown, a molded case circuit breaker structure is disclosed. The mechanism action system 400 includes an upper connecting rod 410, a lower connecting rod 420, and a trip latch 430. The upper connecting rod 410 and the lower connecting rod 420 have an asymmetrical arc-shaped structure and are mechanically connected. The trip latch 430 has a wear-resistant coating on its contact surface and is mechanically connected to the upper connecting rod 410 and the lower connecting rod 420. In this embodiment, the mechanism action system 400 of the high-voltage molded case circuit breaker significantly improves the efficiency and reliability of opening and closing actions by optimizing the connecting rod structure and the trip latch design. Specifically, the mechanism action system 400 includes an upper connecting rod 410, a lower connecting rod 420, and a trip latch 430. The trip latch 430; the upper connecting rod 410 and the lower connecting rod 420 adopt an asymmetrical arc structure. This design reduces the frictional resistance during the tripping process, optimizes the lever ratio, and increases the tripping speed by 15%-20%, ensuring a rapid response and circuit interruption when a short circuit or overload current is detected. At the same time, the contact surface of the trip latch 430 is coated with a wear-resistant coating, which enhances its durability and extends its service life. It is fixed to the upper connecting rod 410 and the lower connecting rod 420 through mechanical connection, ensuring the stability and reliability of the entire mechanism's action system. This design not only improves the circuit breaker's response speed and breaking capacity but also reduces maintenance costs and enhances the circuit breaker's adaptability and stability under complex operating conditions.

[0040] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A molded case circuit breaker structure, characterized in that, include: Circuit breaker housing (1) An arc-extinguishing system (100), located inside the circuit breaker housing (1), is used to interrupt and cool the electric arc; The main circuit system (200) is located on one side of the arc extinguishing system (100) and is used to realize the switching of the circuit. It is connected to the arc extinguishing system (100) and the mechanism action system (400). The thermal magnetic tripping system (300), located on one side of the mechanism action system (400), is used to detect short circuit and overload current and trigger tripping action, and is connected to the mechanism action system (400); The mechanism action system (400) is located on one side of the thermal magnetic trip system (300) and is used to perform opening and closing actions. It is connected to the main circuit system (200) and the thermal magnetic trip system (300). The arc extinguishing system (100) is set on the arc path of the moving contact (210) and stationary contact (220) of the main circuit system (200) to ensure that the arc can enter the arc extinguishing chamber (110) for segmentation and cooling when it is broken. The upper part of the moving contact (210) is provided with a horn-shaped structure, which is used to ignite the arc and make the arc transfer quickly. The arc extinguishing system (100), the main circuit system (200), and the thermomagnetic tripping system (300) are arranged along the first direction, and the main circuit system (200) and the mechanism action system (400) are arranged along the second direction.

2. The structure of a molded case circuit breaker as described in claim 1, characterized in that: The moving contact (210) of the main circuit system (200) is mechanically connected to the mechanism action system (400) to ensure the reliability of the tripping action; the bimetallic strip (320) of the thermomagnetic tripping system (300) is mechanically connected to the mechanism action system (400) to ensure that long-delay protection can be provided under overload conditions when a short circuit or overload current is detected.

3. The structure of a molded case circuit breaker as described in claim 2, characterized in that: The arc extinguishing system (100) includes: The arc-extinguishing chamber (110) is provided with at least 20 metal grid plates (111), which are densely arranged along the second direction; The gas generating component (120) is located inside the arc-extinguishing chamber (110). A Laval tube structure (121) is provided below the gas generating component (120), and the Laval tube structure (121) is fixedly connected to the inner wall of the arc-extinguishing chamber (110).

4. The structure of a molded case circuit breaker as described in claim 3, characterized in that: The main circuit system (200) includes: Moving contact (210) and stationary contact (220); The opening distance between the moving contact (210) and the stationary contact (220) is >30mm; the overtravel between the moving contact (210) and the stationary contact (220) is >2mm; when the moving contact (210) is closed, the distance between the silver point and the grid plate of the arc-extinguishing chamber (110) is >5mm, and when the moving contact (210) is open, the distance between the silver point and the arc-extinguishing chamber (110) is >10mm.

5. The structure of a molded case circuit breaker as described in claim 4, characterized in that: The thermomagnetic tripping system (300) includes: The iron core (310) is a stepped high-permeability material; A bimetallic strip (320) is mechanically connected to the iron core (310).

6. The structure of a molded case circuit breaker as described in claim 5, characterized in that: The mechanism action system (400) includes: an upper connecting rod (410), a lower connecting rod (420), and a jump buckle (430). The upper connecting rod (410) and the lower connecting rod (420) are asymmetrical arc structures. The upper connecting rod (410) and the lower connecting rod (420) are mechanically connected. The contact surface of the jump buckle (430) is provided with a wear-resistant coating, and the jump buckle (430) is mechanically connected to the upper connecting rod (410).

7. The structure of a molded case circuit breaker as described in claim 6, characterized in that: The contact spring (230) of the main circuit system (200) provides a final pressure of >10N to ensure contact stability when the moving contact (210) and the stationary contact (220) are closed.

8. The structure of a molded case circuit breaker as described in claim 7, characterized in that: The circuit breaker housing (1) is provided with a guide groove (160) inside. The guide groove (160) is used to guide the movement of the upper connecting rod (410) and the lower connecting rod (420) of the mechanism action system (400) to ensure the accuracy and stability of the opening and closing actions.

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