Electromagnetic circuit breaker

Abstract

This invention discloses an electromagnetic circuit breaker, comprising a housing assembly, an operating element, a contact support, a moving contact, an operating linkage, a contact linkage, a locking mechanism, a N-pole tripping mechanism, an L-pole tripping mechanism, and an overtravel compensation mechanism. The inner cavity of the housing assembly is divided into an N-pole region and an L-pole region by an isolating seat, with both poles sharing the same operating element. The locking mechanism includes a main locking element and an auxiliary locking element, which are locked together by a limiting groove and an abutment portion. The N-pole tripping mechanism and the L-pole tripping mechanism are independent of each other, but both drive the same auxiliary locking element. In case of a fault, the auxiliary locking element rotates to release the main locking element's limiting position, and the main locking element and the contact support rotate synchronously in the opening direction. The contact support, through the contact linkage, drives the moving contact away from the stationary contact, and through the operating linkage, drives the operating element to rotate to the disconnect position. The overtravel compensation mechanism achieves overtravel compensation through a slotted hole cooperating with a plug shaft and compression of the contact elastic element. This invention has a simplified structure and high integration.

Description

Technical Field

[0001] This invention belongs to the field of low-voltage electrical appliance technology, specifically relating to an electromagnetic circuit breaker. Background Technology

[0002] Currently, conventional electromagnetic residual current circuit breakers on the market generally suffer from bulky overall structure, loose component arrangement, and low integration. To meet multiple functions such as short-circuit protection, overload protection, residual current protection, and stable contact, traditional products require multiple sets of non-interchangeable brackets, latches, transmission components, and contact components. The large number of parts and stacking space result in a large overall size of the circuit breaker, making it difficult to achieve miniaturization at present. This fails to meet the development trends of modern power distribution equipment, which demand small size, multiple functions, high sensitivity, high stability, long life, and easy assembly, as well as the terminal power distribution installation requirements of miniaturization, modularization, and dense wiring.

[0003] In addition, traditional electromagnetic circuit breakers have the following drawbacks: First, the N-pole tripping mechanism and the L-pole tripping mechanism often drive different locking components, resulting in a complex transmission chain, numerous parts, poor synchronization of actions, and a tendency for mutual interference or jamming, affecting the reliability of leakage protection, short-circuit protection, and overload protection. Second, the limiting of the contact support in the locking mechanism is usually not reliable enough, the opening transmission chain is unclear, and locking failure or unreliable disconnection is prone to occur. Third, there is a lack of reliable overtravel compensation structure when the moving contact and the stationary contact are in contact, resulting in unstable contact pressure. This can easily lead to increased contact resistance, excessive temperature rise, or even contact erosion due to contact bounce, wear, or assembly errors. Fourth, the linkage structure between the operating element and the contact support is relatively complex, and the operating linkage is prone to disengagement during opening, resulting in insufficient transmission reliability. Fifth, the components in the N-pole and L-pole areas are scattered, resulting in low space utilization and making it difficult to achieve high integration and miniaturization.

[0004] Therefore, there is a need to design a highly integrated, simplified, miniaturized electromagnetic circuit breaker with a coordinated and independent circuit breaker mechanism to address the aforementioned deficiencies in the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide an electromagnetic circuit breaker to solve the technical problems in the prior art, such as bulky overall structure, loose arrangement of parts, low integration, mutual interference between the N-pole tripping mechanism and the L-pole tripping mechanism, complex transmission chain, unreliable locking, insufficient overtravel compensation of contacts, and unreliable linkage between the operating element and the contact support.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An electromagnetic circuit breaker includes: a housing assembly, the inner cavity of which is divided into an N-pole region and an L-pole region; an operating member rotatably mounted on the housing assembly, the N-pole region and the L-pole region sharing the same operating member; a contact support rotatably mounted inside the housing assembly; a moving contact disposed on one side of the contact support and correspondingly cooperating with a stationary contact; an operating linkage, one end connected to the operating member and the other end cooperating with the contact support; a contact linkage, one end connected to the contact support and the other end connected to the moving contact; a locking mechanism including a main locking member and an auxiliary locking member, the auxiliary locking member being rotatably mounted on the contact support, the main locking member being rotatably mounted on the contact support, the auxiliary locking member and the main locking member being locked together by a limiting groove and a contact portion to restrict the main locking member from rotating in the opening direction; and an N-pole tripping mechanism disposed in the N-pole region. The auxiliary locking mechanism is used to activate the auxiliary locking element in case of a leakage fault, releasing its limit on the main locking element. The L-pole tripping mechanism, located in the L-pole area, is used to activate the auxiliary locking element in case of a short circuit or overload fault, releasing its limit on the main locking element. The auxiliary locking element is driven by both the N-pole and L-pole tripping mechanisms, which are independent and do not interfere with each other. When the circuit breaker switches from a closed to an open state due to a fault, either the N-pole or L-pole tripping mechanism drives the auxiliary locking element to rotate, releasing its limit on the main locking element. After the main locking element is released from its limit, it rotates in the opening direction, and the contact support rotates synchronously in the opening direction. The contact support, through the contact linkage, moves the moving contact away from the stationary contact. Simultaneously, the contact support, through the operating linkage, moves the operating element to the open position.

[0007] By adopting the above technical solution, the inner cavity of the outer casing assembly is divided into an N-pole region and an L-pole region. The N-pole tripping mechanism is located in the N-pole region, and the L-pole tripping mechanism is located in the L-pole region, achieving a zoned arrangement. The N-pole and L-pole regions share the same operating element. The operating element is connected to the contact support via an operating linkage, and the contact support is connected to the moving contact via a contact linkage, forming a complete operating transmission chain. In the locking mechanism, the auxiliary locking element and the main locking element are locked through the limiting cooperation of the limiting groove and the abutment part, restricting the main locking element from rotating in the opening direction, thereby keeping the contact support in the closed position. The N-pole tripping mechanism and the L-pole tripping mechanism are independent of each other and do not interfere with each other, but both can drive the same auxiliary locking element to operate, thereby releasing the limiting effect of the auxiliary locking element on the main locking element. In case of a fault, the auxiliary locking component rotates, and the main locking component, after being released from its limit, rotates in the opening direction. Simultaneously, the contact support rotates in the opening direction. The contact support, via the contact linkage, drives the moving contact away from the stationary contact, and at the same time, via the operating linkage, drives the operating component to rotate to the disconnect position, achieving rapid and reliable disconnection. This structure simplifies the transmission chain, reduces the number of parts, and improves the coordination and reliability of the N and L pole tripping actions, which is beneficial for achieving overall miniaturization and high integration.

[0008] Preferably, the housing assembly includes a bottom shell, a top cover, and an isolation seat; the isolation seat is disposed on the bottom shell, and the isolation seat divides the inner cavity of the housing assembly into an N-pole region and an L-pole region; the N-pole region is located between the bottom shell and the isolation seat, and a current transformer, a circuit board, and an N-pole trip unit are disposed in the N-pole region; the L-pole region is located between the isolation seat and the top cover, and an arc-extinguishing chamber, a thermistor, and an L-pole trip unit are disposed in the L-pole region; the isolation seat has a cutout groove at the position corresponding to the contact bracket.

[0009] By adopting the above technical solution, the isolating base clearly divides the inner cavity of the housing assembly into N-pole and L-pole regions, allowing the N-pole and L-pole trip units to be arranged separately without interference. The N-pole region houses the current transformer, circuit board, and N-pole trip unit, facilitating leakage current detection and tripping; the L-pole region houses the arc-extinguishing chamber, thermistor, and L-pole trip unit, facilitating short-circuit arc extinguishing, overload delay protection, and instantaneous short-circuit protection. The isolating base has perforated slots corresponding to the contact support positions, providing space for the contact support to rotate, ensuring smooth movement, and improving space utilization, resulting in a more compact overall structure.

[0010] Preferably, the contact support includes a contact support cover, a contact support body, and a contact support base; the contact support cover is fastened to the contact support body, and the contact support base is fastened to the contact support body; the contact support body is provided with a central sleeve portion, and a rotating shaft passes through the central sleeve portion, and the contact support body is rotatably connected to the bottom shell through the rotating shaft.

[0011] By adopting the above technical solution, the contact support is composed of a contact support cover, a contact support body, and a contact support base, which are fastened together. This design facilitates assembly, creates a compact structure, and allows for easy installation and replacement of components. The contact support body is rotatably connected to the bottom shell via a central sleeve and a rotating shaft, ensuring stable and reliable rotation. This guarantees that the contact support rotates smoothly around the shaft during closing and opening processes, thereby improving the stability and service life of the circuit breaker.

[0012] Preferably, the auxiliary locking member is rotatably sleeved on the connecting shaft, and the connecting shaft is connected between the first insertion hole on the contact frame body and the second insertion hole on the contact frame cover; the auxiliary locking member includes an abutting part located at the lower position, a limiting part located at the upper position, and a mounting part located at the right side position; the mounting part is provided with a mounting protrusion, and the limiting part is provided with a limiting groove.

[0013] By adopting the above technical solution, the auxiliary locking component is stably installed between the contact frame body and the contact frame cover via a connecting shaft. The two ends of the connecting shaft are positioned by the first and second insertion holes respectively, ensuring reliable installation. The abutment portion below the auxiliary locking component is used to receive the drive of the N-pole tripping mechanism or the L-pole tripping mechanism. The limiting groove on the upper limiting portion is used to cooperate with the main locking component to achieve locking. The mounting protrusion on the right-side mounting portion is used to install the reset elastic component. The rational layout of each functional part helps to reduce the overall size and improve transmission efficiency.

[0014] Preferably, the main locking member is rotatably sleeved on the central sleeve portion of the contact frame body; the main locking member has an abutting portion that abuts against the limiting groove at the position corresponding to the limiting portion; the main locking member has a positioning groove at the position corresponding to the mounting protrusion, and a reset elastic member is provided between the mounting protrusion and the positioning groove, the reset elastic member being used to rotate and reset the auxiliary locking member.

[0015] By adopting the above technical solution, the main locking component and the auxiliary locking component are arranged adjacent to each other. The abutting part of the main locking component abuts against the limiting groove of the auxiliary locking component, achieving a locking engagement and restricting the rotation of the main locking component in the opening direction. The reset elastic component is located between the mounting protrusion and the positioning groove. After the auxiliary locking component rotates to release the lock, it can rotate and reset the auxiliary locking component, ensuring the reliability of the next locking action and improving the stability of the circuit breaker's repeated operation.

[0016] Preferably, a recessed groove is provided above the main body of the contact holder, the recessed groove having a downwardly extending vertical section and a horizontal section located on the right side above the vertical section; one end of the operating linkage is inserted into the operating component, and the other end is inserted into the recessed groove; an abutting protrusion adapted to the recessed groove is provided on one side of the contact holder main body located in the recessed groove; an arc-shaped section adapted to the shape of the recessed groove is provided on the main locking component at the position corresponding to the abutting protrusion, and the other end of the operating linkage is located between the abutting protrusion and the arc-shaped section; a blocking protrusion is provided on the top of the arc-shaped section of the main locking component, the blocking protrusion being used to prevent the operating linkage from disengaging from the recessed groove.

[0017] By adopting the above technical solution, one end of the operating linkage is inserted into the operating component, and the other end is inserted into the recessed groove of the contact holder body, located between the abutment protrusion and the arc-shaped section of the main locking component, thus achieving reliable linkage between the operating component and the contact holder. The vertical and horizontal sections of the recessed groove provide movement space for the operating linkage, while the abutment protrusion and the arc-shaped section limit and guide the operating linkage. The blocking protrusion at the top of the arc-shaped section of the main locking component prevents the operating linkage from disengaging from the recessed groove, preventing transmission failure and improving the reliability of the linkage between the operating component and the contact holder.

[0018] Preferably, the N-pole tripping mechanism includes an N-pole trip unit and an actuating member; the N-pole trip unit includes an extension rod; the actuating member is rotatably mounted on the bottom shell, and the actuating member includes a rotating sleeve portion, a pressure receiving portion located on one side of the rotating sleeve portion, and a pressing portion located on the other side of the rotating sleeve portion; the pressure receiving portion is correspondingly arranged with the extension rod, and the pressing portion is correspondingly arranged with the abutting portion of the auxiliary locking member; the extension rod can extend to abut against the pressure receiving portion and drive the actuating member to rotate, so that the pressing portion abuts against the abutting portion and drives the limiting portion of the auxiliary locking member to rotate away from the main locking member, so that the abutting portion disengages from the limiting groove.

[0019] By adopting the above technical solution, the N-pole trip unit drives the extension rod to extend in the event of a leakage fault. The extension rod pushes the pressure part of the actuating element, causing the actuating element to rotate around the rotating sleeve part. The pressure part pushes the contact part of the auxiliary locking element, causing the auxiliary locking element to rotate. The limiting part moves away from the main locking element, and the contact part disengages from the limiting groove, completing the leakage trip. This structure converts the linear extension motion of the N-pole trip unit into the rotation of the actuating element, which then drives the rotation of the auxiliary locking element. The transmission is reliable, the structure is compact, and it can effectively achieve rapid disconnection in the event of a leakage fault.

[0020] Preferably, the pressure-bearing part is provided with an abutting protrusion; a torsional elastic element is provided between the contact frame body and the contact frame base, one end of the torsional elastic element abuts against the contact frame body or the contact frame base, and the other end extends out of the contact support and abuts against the abutting protrusion. After the contact support is disconnected and reset, the torsional elastic element drives the abutting protrusion and the actuating element to rotate, thereby realizing the reset of the actuating element and the extension rod.

[0021] By adopting the above technical solution, a torsional elastic element is disposed between the contact frame body and the contact frame base, with its other end extending out of the contact support and abutting abutting abutment protrusion on the pressure-bearing part. After the contact support disconnects and resets, the torsional elastic element can drive the abutment protrusion and the actuating element to rotate, thereby resetting the actuating element and the extending rod, ensuring that the N-pole tripping mechanism can repeat its operation. This reset structure makes full use of the internal space of the contact support, has a compact structure, reliable reset, and improves the stability and service life of the circuit breaker after multiple trips.

[0022] Preferably, the L-pole tripping mechanism includes an L-pole trip unit, a sliding member, a thermal element, and a connecting rod; a guide groove is provided on the isolating seat corresponding to the position of the L-pole trip unit, the sliding member is disposed in the guide groove of the isolating seat, and the sliding member includes a pushing part on the side near the L-pole trip unit and a protruding part on the side away from the L-pole trip unit; a sliding elastic member is provided between the protruding part and the isolating seat; the connecting rod is disposed in a cavity groove inside the sliding member, and the connecting rod abuts against the thermal element; a plug is provided on the sliding member corresponding to the position of the cavity groove, the plug is inserted into the cavity groove, and the connecting rod is positioned and installed in the cavity. In the groove; a pressing block is provided on the sliding member at the position of the contact part corresponding to the auxiliary locking member; when short circuit, the L-pole trip unit pushes the pushing part, causing the sliding member to move away from the L-pole trip unit in the guide groove, and the pressing block presses against the contact part and causes the auxiliary locking member to rotate; when overload, the thermal element expands due to heat, causing the connecting rod and the sliding member to slide towards the auxiliary locking member, causing the pressing block to press against the contact part and drive the auxiliary locking member to rotate; a partition is provided on the isolating seat above the sliding member, and the sliding member is positioned between the isolating seat and the partition, and the sliding member can slide in the guide groove.

[0023] By adopting the above technical solution, the L-pole tripping mechanism simultaneously possesses both instantaneous short-circuit protection and overload time-delay protection functions. During a short circuit, the L-pole trip unit directly pushes the sliding member's pushing part, causing the sliding member to move away from the L-pole trip unit within the guide groove. The pressing block on the sliding member presses against the abutting part of the auxiliary locking member, driving the auxiliary locking member to rotate, thus achieving instantaneous short-circuit tripping. During an overload, the thermal element expands due to heat, driving the sliding member to move via the connecting rod. The pressing block similarly drives the auxiliary locking member to rotate, achieving overload time-delay tripping. The connecting rod is positioned and installed in the sliding member's cavity groove via a plug, facilitating assembly and ensuring reliable positioning. The sliding member is positioned by an isolating seat and a partition plate, ensuring stable movement. The sliding elastic element provides a restoring force, guaranteeing reliable repeated action. This structure integrates short-circuit tripping and overload tripping into the same L-pole tripping mechanism, simplifying the structure and improving the integration and reliability of the protection functions.

[0024] Preferably, it further includes an overtravel compensation mechanism, which includes a contact link, a shaft, and a contact elastic element; one end of the contact link is connected to the contact support, and the other end is connected to the contact insertion hole of the moving contact; a transverse strip hole is provided on the moving contact at the position corresponding to the shaft, and the strip hole slides with the shaft; a protrusion is provided on the moving contact between the contact insertion hole and the strip hole; a receiving groove is provided on the isolating seat and / or the bottom shell at the position corresponding to the moving contact; the contact elastic element is provided in the receiving groove and the protrusion. Between the parts; when the moving contact contacts the stationary contact, the contact elastic element is compressed, and a relative displacement occurs between the strip hole and the insertion shaft, realizing overtravel compensation; there are two moving contacts, namely an L-pole moving contact and an N-pole moving contact. The contact connecting rod of the L-pole moving contact is connected to the insertion hole of the contact frame body, and the contact connecting rod of the N-pole moving contact is connected to the insertion hole of the contact frame base; there are receiving grooves on the isolating seat corresponding to the position of the L-pole moving contact and on the bottom shell corresponding to the position of the N-pole moving contact.

[0025] By adopting the above technical solution, the moving contact is connected to the contact support via a contact connecting rod. The strip hole on the moving contact slides with the insertion shaft, and the contact elastic element is located between the receiving groove and the protrusion. During closing, the moving contact continues to move after contacting the stationary contact, compressing the contact elastic element and generating relative displacement between the strip hole and the insertion shaft, achieving overtravel compensation. This ensures reliable contact pressure between the moving and stationary contacts, reducing contact resistance and temperature rise, and improving electrical connection stability and service life. The L-pole moving contact and N-pole moving contact are connected via insertion holes on the contact frame body and contact frame base, respectively, resulting in a compact structure suitable for double-pole circuit breakers. Receiving grooves are provided on the isolating seat and bottom shell corresponding to the L-pole and N-pole moving contacts, respectively, making the installation and stress of the contact elastic element more reasonable and ensuring good overtravel compensation effect for both double-pole contacts.

[0026] Compared with the prior art, the present invention has, but is not limited to, the following beneficial effects: 1. The N-pole tripping mechanism and the L-pole tripping mechanism are independent of each other and do not interfere with each other, but they both drive the same auxiliary locking component, which simplifies the transmission chain, reduces the number of parts, improves space utilization and operational reliability, and solves the problems of mutual interference, complex transmission chain and large number of parts in traditional circuit breaker N-pole tripping mechanisms and L-pole tripping mechanisms.

[0027] 2. In the locking mechanism, the auxiliary locking component and the main locking component are locked together through the limiting cooperation of the limiting groove and the abutment part, restricting the main locking component from rotating in the opening direction, thereby reliably holding the contact support in the closed position. In case of a fault, the rotation of the auxiliary locking component can release the limiting of the main locking component. The main locking component and the contact support rotate synchronously in the opening direction. The contact support drives the moving contact away from the stationary contact through the contact connecting rod, and at the same time drives the operating component to rotate to the disconnect position through the operating connecting rod, realizing fast and reliable disconnection. This solves the problems of unreliable locking and complex disconnection transmission chain of traditional circuit breakers.

[0028] 3. The N-pole tripping mechanism drives the actuating element via the extension rod of the N-pole trip unit, which in turn drives the auxiliary locking element to achieve leakage current tripping. The L-pole tripping mechanism drives the sliding element via the L-pole trip unit or a thermal element, which in turn drives the auxiliary locking element to achieve short circuit and overload tripping. Both tripping mechanisms act on the same auxiliary locking element, but they are independent of each other and do not interfere with each other, achieving multiple protections against leakage current, short circuit, and overload, thus improving the integration and reliability of the circuit breaker's protection functions.

[0029] 4. The overtravel compensation mechanism achieves overtravel compensation when the moving contact and the stationary contact are in contact through the sliding fit between the strip hole on the moving contact and the insert shaft, as well as the compression of the contact elastic element between the receiving groove and the protrusion. This ensures a stable contact pressure between the moving contact and the stationary contact, effectively reduces contact resistance and temperature rise, improves electrical connection stability and service life, and solves the problems of insufficient overtravel compensation and unstable contact pressure in traditional circuit breaker contacts. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention in the open state according to a specific embodiment; Figure 3 This is a schematic diagram of the structure of a specific embodiment of the present invention in the closed state; Figure 4 This is a schematic diagram illustrating the structure of the moving contact and stationary contact when they are in overtravel contact according to a specific embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the structure of the bottom shell in a specific embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the structure of the isolation seat according to a specific embodiment of the present invention; Figure 7 This is a schematic diagram illustrating the structure of the contact support according to a specific embodiment of the present invention; Figure 8 This is a schematic diagram illustrating the connection structure of the contactor frame cover, the contactor frame body, and the contactor frame base in a specific embodiment of the present invention. Figure 1 ; Figure 9 This is a schematic diagram illustrating the connection structure of the contactor frame cover, the contactor frame body, and the contactor frame base in a specific embodiment of the present invention. Figure 2 ; Figure 10 This is a schematic diagram illustrating the structure of the contact frame cover according to a specific embodiment of the present invention; Figure 11 This is a schematic diagram illustrating the structure of the contactor frame body according to a specific embodiment of the present invention; Figure 12This is a schematic diagram illustrating the structure of the contactor frame base according to a specific embodiment of the present invention; Figure 13 This is a schematic diagram illustrating the structure of a torsional elastic element according to a specific embodiment of the present invention; Figure 14 This is a schematic diagram illustrating the structure of the auxiliary locking component according to a specific embodiment of the present invention; Figure 15 This is a schematic diagram illustrating the structure of the main locking component in a specific embodiment of the present invention; Figure 16 This is a schematic diagram illustrating the structure of the moving contact in a specific embodiment of the present invention; Figure 17 This is a schematic diagram illustrating the structure of the operating element, contact support, and moving contact in the open position according to a specific embodiment of the present invention; Figure 18 This is a schematic diagram illustrating the structure of the operating element, contact support, and moving contact in the closed position according to a specific embodiment of the present invention; Figure 19 This is a schematic diagram illustrating the structure of the auxiliary locking member after rotation and the cancellation of the limiting effect on the main locking member in a specific embodiment of the present invention; Figure 20 This is a schematic diagram illustrating the structure of the N-pole moving contact connected to the contact frame base via a contact connecting rod, according to a specific embodiment of the present invention. Figure 21 This is a schematic diagram illustrating the structure of the N-pole tripping mechanism according to a specific embodiment of the present invention; Figure 22 This is a schematic diagram illustrating the structure of the actuating component according to a specific embodiment of the present invention; Figure 23 This is a schematic diagram illustrating the structure of the L-pole tripping mechanism according to a specific embodiment of the present invention; Figure 24 This is a schematic diagram illustrating the structure of the sliding member located between the isolation seat and the partition plate in a specific embodiment of the present invention; Figure 25 This is a schematic diagram illustrating the structure of the partition in a specific embodiment of the present invention; Figure 26 This is a schematic diagram illustrating the structure of the slider and connecting rod according to a specific embodiment of the present invention; Figure 27 This is a schematic diagram illustrating the structure of the sliding component according to a specific embodiment of the present invention; Figure 28 This is a schematic diagram illustrating the structure of the plug positioning the connecting rod in the cavity groove, as shown in a specific embodiment of the present invention.

[0031] In the diagram: 100, outer casing assembly; 101, bottom shell; 102, top cover; 103, current transformer; 104, circuit board; 105, arc-extinguishing chamber; 106, isolating seat; 107, perforated groove; 108, guide slide; 109, partition plate; 110, operating component; 111, operating linkage; 112, receiving slot; 200, contact bracket; 201, contact bracket cover; 202, contact bracket body; 203, contact bracket. 204. Base; 205. Central sleeve; 206. Rotating shaft; 207. Insertion hole; 208. Recessed groove; 209. Vertical section; 200. Horizontal section; 210. Abutting protrusion; 211. First insertion hole; 212. Second insertion hole; 213. Torsional elastic element; 300. Moving contact; 301. Contact connecting rod; 302. Insertion shaft; 303. Contact elastic element; 304. Contact insertion hole; 305. Strip hole; 306. Protrusion; 3 07. Stationary contact; 400. Locking mechanism; 401. Main locking element; 402. Auxiliary locking element; 403. Arc-shaped section; 404. Blocking protrusion; 405. Connecting shaft; 406. Abutting part; 407. Limiting part; 408. Mounting part; 409. Mounting protrusion; 410. Limiting groove; 411. Abutting part; 412. Positioning groove; 413. Reset elastic element; 500. N-pole tripping mechanism; 501. N-pole trip unit 502. Actuating element; 503. Extending rod; 504. Rotating sleeve part; 505. Pressing part; 506. Pressing part; 507. Abutting protrusion; 600. L-pole tripping mechanism; 601. L-pole tripping device; 602. Sliding element; 603. Thermistor element; 604. Connecting rod; 605. Pushing part; 606. Protruding column part; 607. Sliding elastic element; 608. Cavity groove; 609. Plug; 610. Pressing block. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0033] The following is combined with Figures 1-28 The technical solution of the present invention will be described in further detail below.

[0034] This embodiment provides an electromagnetic circuit breaker, which adopts a partitioned arrangement of N-pole and L-pole regions. The N-pole tripping mechanism 500 and the L-pole tripping mechanism 600 are independent and do not interfere with each other, but both drive the same auxiliary locking element 402, thereby achieving a high degree of integration of leakage protection, short-circuit protection and overload protection. The electromagnetic circuit breaker includes a housing assembly 100, an operating element 110, a contact support 200, a moving contact 300, an operating linkage 111, a contact linkage 301, a locking mechanism 400, an N-pole tripping mechanism 500, an L-pole tripping mechanism 600, and an overtravel compensation mechanism.

[0035] Housing assembly 100 and operating element 110 The housing assembly 100 includes a bottom shell 101, a top cover 102, and an isolation seat 106. The isolation seat 106 is disposed on the bottom shell 101 and divides the inner cavity of the housing assembly 100 into an N-pole region and an L-pole region. The N-pole region is located between the bottom shell 101 and the isolation seat 106, and contains a current transformer 103, a circuit board 104, and an N-pole trip unit 501. The L-pole region is located between the isolation seat 106 and the top cover 102, and contains an arc-extinguishing chamber 105, a thermistor 603, and an L-pole trip unit 601. The isolation seat 106 has a slot 107 corresponding to the position of the contact support 200, allowing the contact support 200 to rotate between the N-pole and L-pole regions. The isolation seat 106 has a guide groove 108 corresponding to the position of the L-pole trip unit 601, and a sliding element 602 is disposed within the guide groove 108. A partition 109 is provided on the isolation seat 106 above the slider 602. The slider 602 is positioned between the isolation seat 106 and the partition 109 and can slide in the guide groove 108.

[0036] The operating element 110 is rotatably mounted on the housing assembly 100, and the N-pole region and the L-pole region share the same operating element 110. The operating element 110 is connected to the contact support 200 through the operating linkage 111, thereby driving the contact 300 support 200 to rotate.

[0037] Contact support 200 and moving contact 300 The contact support 200 is rotatably mounted within the housing assembly 100. The contact support 200 includes a contact support cover 201, a contact support body 202, and a contact support base 203. The contact support cover 201 is snap-fitted to the contact support body 202, and the contact support base 203 is snap-fitted to the contact support body 202. The contact support body 202 has a central sleeve portion 204, through which a rotating shaft 205 passes. The contact support body 202 is rotatably connected to the bottom shell 101 via the rotating shaft 205.

[0038] The moving contact 300 is located on one side of the contact support 200 and corresponds to the stationary contact 307. There are two moving contacts 300, namely an L-pole moving contact 300 and an N-pole moving contact 300. The contact connecting rod 301 of the L-pole moving contact 300 is connected to the insertion hole 206 of the contact support body 202, and the contact connecting rod 301 of the N-pole moving contact 300 is connected to the insertion hole 206 of the contact support base 203.

[0039] One end of the operating linkage 111 is inserted into the operating member 110, and the other end is inserted into the recess 207 of the contact holder body 202. The recess 207 is located at the top of the contact holder body 202 and has a downwardly extending vertical section 208 and a horizontal section 209 located on the right side above the vertical section 208. A mating protrusion 210 is provided on one side of the contact holder body 202 corresponding to the recess 207. An arc-shaped section 403 corresponding to the shape of the recess 207 is provided on the main locking member 401 at the position corresponding to the mating protrusion 210. The other end of the operating linkage 111 is located between the mating protrusion 210 and the arc-shaped section 403. A blocking protrusion 404 is provided on the top of the arc-shaped section 403 of the main locking member 401. The blocking protrusion 404 is used to prevent the operating linkage 111 from disengaging from the recess 207.

[0040] Locking mechanism 400 The locking mechanism 400 includes a main locking member 401 and an auxiliary locking member 402. The auxiliary locking member 402 is rotatably mounted on the contact support 200, and the main locking member 401 is rotatably mounted on the contact support 200. The auxiliary locking member 402 is rotatably sleeved on a connecting shaft 405, which connects to a first insertion hole 211 on the contact frame body 202 and a second insertion hole 212 on the contact frame cover 201. The auxiliary locking member 402 includes an abutment portion 406 located at the lower position, a limiting portion 407 located at the upper position, and a mounting portion 408 located at the right side position. The mounting portion 408 is provided with a mounting protrusion 409, and the limiting portion 407 is provided with a limiting groove 410.

[0041] The main locking member 401 is rotatably sleeved on the central sleeve portion 204 of the contact bracket body 202. The main locking member 401 has an abutment portion 411 corresponding to the position of the limiting portion 407, which abuts against the limiting groove 410. The main locking member 401 has a positioning groove 412 corresponding to the position of the mounting protrusion 409, and a reset elastic member 413 is provided between the mounting protrusion 409 and the positioning groove 412. The reset elastic member 413 is used to rotate and reset the auxiliary locking member 402. The auxiliary locking member 402 and the main locking member 401 are locked together by the limiting cooperation between the limiting groove 410 and the abutment portion 411, thereby restricting the main locking member 401 from rotating in the opening direction and thus keeping the contact bracket 200 in the closed position.

[0042] N-pole tripping mechanism 500 The N-pole tripping mechanism 500 is located in the N-pole region and is used to drive the auxiliary locking member 402 to actuate and release the limiting effect of the auxiliary locking member 402 on the main locking member 401 in the event of a leakage fault. The N-pole tripping mechanism 500 includes an N-pole trip unit 501 and an actuating member 502. The N-pole trip unit 501 includes an extension rod 503. The actuating member 502 is rotatably mounted on the bottom shell 101 and includes a rotating sleeve portion 504, a pressure receiving portion 505 located on one side of the rotating sleeve portion 504, and a pressing portion 506 located on the other side of the rotating sleeve portion 504. The pressure receiving portion 505 is correspondingly arranged with the extension rod 503, and the pressing portion 506 is correspondingly arranged with the abutting portion 406 of the auxiliary locking member 402.

[0043] The extension rod 503 can extend to abut against the pressure-bearing part 505 and drive the actuating member 502 to rotate, causing the pressure-bearing part 506 to abut against the contact part 406 and driving the limiting part 407 of the auxiliary locking member 402 to rotate away from the main locking member 401, causing the contact part 411 to disengage from the limiting groove 410. The pressure-bearing part 505 is provided with an abutting protrusion 507. A torsional elastic member 213 is provided between the contact holder body 202 and the contact holder base 203. One end of the torsional elastic member 213 abuts against the contact holder body 202 or the contact holder base 203, and the other end extends out of the contact support 200 and abuts against the abutting protrusion 507. After the contact support 200 is disconnected and reset, the torsional elastic member 213 drives the abutting protrusion 507 and the actuating member 502 to rotate, thereby resetting the actuating member 502 and the extension rod 503.

[0044] L-stage tripping mechanism 600 The L-pole tripping mechanism 600 is located in the L-pole region and is used to drive the auxiliary locking member 402 to actuate and release the auxiliary locking member 402 from the main locking member 401 in the event of a short circuit or overload fault. The L-pole tripping mechanism 600 includes an L-pole trip unit 601, a sliding member 602, a thermal element 603, and a connecting rod 604. The sliding member 602 is located in the guide groove 108 of the isolation seat 106 and includes a pushing part 605 on the side near the L-pole trip unit 601 and a protruding part 606 on the side away from the L-pole trip unit 601. A sliding elastic member 607 is provided between the protruding part 606 and the isolation seat 106. The connecting rod 604 is located in the cavity groove 608 inside the sliding member 602 and is in contact with the thermal element 603. A plug 609 is provided on the sliding member 602 at the position corresponding to the cavity groove 608. The plug 609 is inserted into the cavity groove 608 and the connecting rod 604 is positioned and installed in the cavity groove 608. A pressing block 610 is provided on the sliding member 602 at the position corresponding to the abutment part 406 of the auxiliary locking member 402.

[0045] When a short circuit occurs, the L-pole trip unit 601 pushes the pusher part 605, causing the slider 602 to move away from the L-pole trip unit 601 in the guide groove 108. The pressing block 610 presses against the abutment part 406, causing the auxiliary locking member 402 to rotate. When an overload occurs, the thermal element 603 expands due to heat, causing the connecting rod 604 and the slider 602 to slide towards the auxiliary locking member 402, causing the pressing block 610 to press against the abutment part 406, thereby causing the auxiliary locking member 402 to rotate.

[0046] Overdistance compensation agency The overtravel compensation mechanism includes a contact link 301, a insertion shaft 302, and a contact elastic element 303. One end of the contact link 301 is connected to the contact support 200, and the other end is connected to the contact insertion hole 304 of the moving contact 300. A transverse strip hole 305 is provided on the moving contact 300 corresponding to the insertion shaft 302, and the strip hole 305 is slidably engaged with the insertion shaft 302. A protrusion 306 is provided on the moving contact 300 between the contact insertion hole 304 and the strip hole 305. A receiving groove 112 is provided on the isolating seat 106 and / or the bottom shell 101 corresponding to the moving contact 300. The contact elastic element 303 is located between the receiving groove 112 and the protrusion 306. When the moving contact 300 contacts the stationary contact 307, the contact elastic element 303 is compressed, and a relative displacement occurs between the strip hole 305 and the insertion shaft 302, achieving overtravel compensation. The isolating seat 106 is provided with a receiving groove 112 at the position corresponding to the L pole moving contact 300 and the bottom shell 101 is provided with a receiving groove 112 at the position corresponding to the N pole moving contact 300.

[0047] Closed state When the circuit breaker is in the closed state, the operating member 110 is in the closed position. One end of the operating linkage 111 is inserted into the operating member 110, and the other end is located between the arc-shaped section 403 of the main locking member 401 and the abutment protrusion 210 of the contact frame body 202. The limiting groove 410 of the auxiliary locking member 402 is matched with the abutment part 411 of the main locking member 401 to limit the rotation of the main locking member 401 in the opening direction, thereby keeping the contact frame 200 in the closed position. At this time, the moving contact 300 abuts against the stationary contact 307, the strip hole 305 cooperates with the insert shaft 302, and the contact elastic member 303 is compressed, realizing overtravel. Because the counter-pushing force of the contact elastic element 303 is transmitted to the contact frame body 202 and the contact frame base 203 through the contact connecting rod 301, the abutting protrusion 210 on the contact frame body 202 applies a force to the other end of the operating connecting rod 111, and the other end of the operating connecting rod 111 applies a force to the arc-shaped section 403 of the main locking element 401, causing the main locking element 401 to have a tendency to rotate in the opening direction. However, because the abutting part 411 of the main locking element 401 is limited by the limiting groove 410 of the auxiliary locking element 402, the main locking element 401 cannot rotate in the opening direction, and the contact support 200 remains in the closed position.

[0048] Leakage tripping disconnection process When a leakage fault occurs in the circuit, the extension rod 503 of the N-pole trip unit 501 extends, pushing the pressure part 505 of the actuating member 502, causing the actuating member 502 to rotate around the rotating sleeve part 504. The pressing part 506 of the actuating member 502 pushes the contact part 406 of the auxiliary locking member 402, causing the auxiliary locking member 402 to rotate. The limiting part 407 of the auxiliary locking member 402 moves away from the main locking member 401, and the contact part 411 of the main locking member 401 disengages from the limiting groove 410. After the main locking member 401 is released from its limit, it rotates in the opening direction, and the contact bracket 200 rotates synchronously in the opening direction. The contact bracket 200 drives the moving contact 300 away from the stationary contact 307 via the contact connecting rod 301, and at the same time, the contact bracket 200 drives the operating member 110 to rotate to the disconnect position via the operating connecting rod 111, realizing the leakage trip disconnection.

[0049] Short circuit tripping process When a short circuit fault occurs, the L-pole trip unit 601 actuates, pushing the pushing part 605 of the sliding member 602. The sliding member 602 moves away from the L-pole trip unit 601 in the guide groove 108, and the pressing block 610 on the sliding member 602 presses against the abutting part 406 of the auxiliary locking member 402, causing the auxiliary locking member 402 to rotate. The limiting part 407 of the auxiliary locking member 402 moves away from the main locking member 401, and the abutting part 411 of the main locking member 401 disengages from the limiting groove 410. After the main locking member 401 is released from its limiting position, it rotates in the opening direction, and the contact bracket 200 rotates synchronously in the opening direction. The contact bracket 200 drives the moving contact 300 away from the stationary contact 307 through the contact connecting rod 301, and at the same time, the contact bracket 200 drives the operating member 110 to rotate to the disconnect position through the operating connecting rod 111, realizing the short circuit tripping disconnection.

[0050] Overload tripping process When an overload fault occurs in the circuit, the thermal element 603 expands due to heat, causing the connecting rod 604 to move. Since the connecting rod 604 is positioned in the cavity groove 608 of the sliding member 602 by the plug 609, the connecting rod 604 causes the sliding member 602 to slide towards the auxiliary locking member 402. The pressing block 610 on the sliding member 602 presses against the contact portion 406 of the auxiliary locking member 402, causing the auxiliary locking member 402 to rotate. The limiting portion 407 of the auxiliary locking member 402 moves away from the main locking member 401, and the contact portion 411 of the main locking member 401 disengages from the limiting groove 410. After the main locking member 401 is released from its limiting position, it rotates in the opening direction, and the contact bracket 200 rotates synchronously in the opening direction. The contact bracket 200 drives the moving contact 300 away from the stationary contact 307 via the contact connecting rod 301. At the same time, the contact bracket 200 drives the operating member 110 to rotate to the disconnect position via the operating connecting rod 111, thereby realizing overload tripping and disconnection.

[0051] Reset process After the contact support 200 is disconnected and reset, the torsional elastic element 213 drives the abutment protrusion 507 and the actuating element 502 to rotate, thereby resetting the actuating element 502 and the extension rod 503. The reset elastic element 413 rotates and resets the auxiliary locking element 402, causing the limiting groove 410 of the auxiliary locking element 402 to re-engage with the abutment part 411 of the main locking element 401. The sliding elastic element 607 provides a moving reset for the sliding element 602, allowing the sliding element 602 to reset in the guide groove 108. The various reset mechanisms cooperate with each other to ensure that the circuit breaker can reliably reset and repeat operation after multiple trips and openings.

[0052] It should be understood that the above embodiments are merely illustrative examples and are not intended to limit the invention. Based on the above embodiments, those skilled in the art can make appropriate adjustments and modifications to the specific shape and size of the housing assembly 100, the specifications and elastic parameters of each elastic element, the specific shape of the contact support 200 and the locking element, the cooperation relationship between the N-pole tripping mechanism 500 and the L-pole tripping mechanism 600, and the specific arrangement of the overtravel compensation mechanism, according to actual application requirements. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of the claims of this invention should be included within the scope of protection of this invention.

Claims

1. An electromagnetic circuit breaker, characterized in that, include: The housing assembly (100) has its interior cavity divided into an N-pole region and an L-pole region; An operating element (110) is rotatably mounted on the housing assembly (100), and the N-pole region and the L-pole region share the same operating element (110); The contact support (200) is rotatably disposed within the housing assembly (100); The moving contact (300) is located on one side of the contact support (200) and corresponds to and cooperates with the stationary contact (307); The operating linkage (111) is connected at one end to the operating element (110) and at the other end to the contact bracket (200); The contact link (301) is connected at one end to the contact support (200) and at the other end to the moving contact (300); The locking mechanism (400) includes a main locking member (401) and an auxiliary locking member (402). The auxiliary locking member (402) is rotatably mounted on the contact support (200), and the main locking member (401) is rotatably mounted on the contact support (200). The auxiliary locking member (402) and the main locking member (401) are locked together by the limiting cooperation of the limiting groove (410) and the abutment part (411) to restrict the main locking member (401) from rotating in the opening direction. The N-pole tripping mechanism (500) is located in the N-pole area and is used to drive the auxiliary locking member (402) to act in the event of a leakage fault, thereby releasing the limit of the auxiliary locking member (402) on the main locking member (401). The L-pole tripping mechanism (600) is located in the L-pole region and is used to drive the auxiliary locking member (402) to act in the event of a short circuit or overload fault, thereby releasing the auxiliary locking member (402) from the main locking member (401). The auxiliary locking component (402) is driven by both the N-pole tripping mechanism (500) and the L-pole tripping mechanism (600). The N-pole tripping mechanism (500) and the L-pole tripping mechanism (600) are independent of each other and do not interfere with each other. When the circuit breaker switches from the closed state to the open state due to a fault, the N-pole tripping mechanism (500) or the L-pole tripping mechanism (600) drives the auxiliary locking member (402) to rotate, and the auxiliary locking member (402) releases the limit on the main locking member (401); after the main locking member (401) is released from the limit, it rotates in the opening direction, and the contact bracket (200) rotates in the opening direction simultaneously; the contact bracket (200) drives the moving contact (300) away from the stationary contact (307) through the contact connecting rod (301); at the same time, the contact bracket (200) drives the operating member (110) to rotate to the open position through the operating connecting rod (111).

2. The electromagnetic circuit breaker according to claim 1, characterized in that, The housing assembly (100) includes a bottom shell (101), a top cover (102), and an isolation seat (106). The isolation seat (106) is located on the bottom shell (101) and divides the inner cavity of the housing assembly (100) into an N-pole region and an L-pole region. The N-pole region is located between the bottom shell (101) and the isolation seat (106) and is equipped with a current transformer (103), a circuit board (104), and an N-pole trip unit (501). The L-pole region is located between the isolation seat (106) and the top cover (102) and is equipped with an arc-extinguishing chamber (105), a thermistor (603), and an L-pole trip unit (601). The isolation seat (106) has a cutout groove (107) corresponding to the position of the contact bracket (200).

3. The electromagnetic circuit breaker according to claim 2, characterized in that, The contact support (200) includes a contact support cover (201), a contact support body (202), and a contact support base (203); the contact support cover (201) is fastened to the contact support body (202), and the contact support base (203) is fastened to the contact support body (202); the contact support body (202) is provided with a central sleeve part (204), and a rotating shaft (205) passes through the central sleeve part (204), and the contact support body (202) is rotatably connected to the bottom shell (101) through the rotating shaft (205).

4. The electromagnetic circuit breaker according to claim 3, characterized in that, The auxiliary locking member (402) is rotatably sleeved on the connecting shaft (405), which is connected between the first insertion hole (211) on the contact holder body (202) and the second insertion hole (212) on the contact holder cover (201). The auxiliary locking member (402) includes an abutting part (406) located at the lower position, a limiting part (407) located at the upper position, and a mounting part (408) located at the right side position. The mounting part (408) is provided with a mounting protrusion (409), and the limiting part (407) is provided with a limiting groove (410).

5. The electromagnetic circuit breaker according to claim 4, characterized in that, The main locking member (401) is rotatably sleeved on the central sleeve portion (204) of the contact frame body (202); the main locking member (401) is provided with an abutting portion (411) that abuts against the limiting portion (410) at the position corresponding to the limiting portion (407); the main locking member (401) is provided with a positioning groove (412) corresponding to the position of the mounting protrusion (409), and a reset elastic member (413) is provided between the mounting protrusion (409) and the positioning groove (412), and the reset elastic member (413) is used to rotate and reset the auxiliary locking member (402).

6. The electromagnetic circuit breaker according to claim 5, characterized in that, A recessed groove (207) is provided at the upper part of the contact holder body (202). The recessed groove (207) has a downwardly extending vertical section (208) and a horizontal section (209) located on the right side above the vertical section (208). One end of the operating linkage (111) is inserted into the operating member (110), and the other end is inserted into the recessed groove (207). An abutting protrusion (210) adapted to the recessed groove (207) is provided on one side of the contact holder body (202). The main locking member (401) has an arc-shaped segment (403) that matches the shape of the recessed groove (207) at the position corresponding to the abutting protrusion (210). The other end of the operating link (111) is located between the abutting protrusion (210) and the arc-shaped segment (403). The main locking member (401) has a blocking protrusion (404) at the top of the arc-shaped segment (403). The blocking protrusion (404) is used to restrict the operating link (111) from disengaging from the recessed groove (207).

7. The electromagnetic circuit breaker according to claim 1, characterized in that, The N-pole tripping mechanism (500) includes an N-pole trip unit (501) and an actuating member (502); the N-pole trip unit (501) includes an extension rod (503); the actuating member (502) is rotatably mounted on the base shell (101), and the actuating member (502) includes a rotating sleeve portion (504), a pressure receiving portion (505) located on one side of the rotating sleeve portion (504), and a pressing portion (506) located on the other side of the rotating sleeve portion (504); the pressure receiving portion (505) and the extension rod (503) Correspondingly, the pressing part (506) and the contact part (406) of the auxiliary locking member (402) are correspondingly provided; the extension rod (503) can extend to abut against the pressing part (505) and drive the actuating member (502) to rotate, so that the pressing part (506) abuts against the contact part (406) and drives the limiting part (407) of the auxiliary locking member (402) to rotate away from the main locking member (401), so that the contact part (411) disengages from the limiting groove (410).

8. The electromagnetic circuit breaker according to claim 7, characterized in that, The pressure-bearing part (505) is provided with an abutment protrusion (507); a torsional elastic element (213) is provided between the contact frame body (202) and the contact frame base (203). One end of the torsional elastic element (213) abuts against the contact frame body (202) or the contact frame base (203), and the other end extends out of the contact support (200) and abuts against the abutment protrusion (507). After the contact support (200) is disconnected and reset, the torsional elastic element (213) drives the abutment protrusion (507) and the actuating element (502) to rotate, and realizes the reset of the actuating element (502) and the extension rod (503).

9. The electromagnetic circuit breaker according to claim 2, characterized in that, The L-pole tripping mechanism (600) includes an L-pole trip unit (601), a sliding member (602), a thermal element (603), and a connecting rod (604); a guide groove (108) is provided on the isolating seat (106) at a position corresponding to the L-pole trip unit (601), and the sliding member (602) is disposed in the guide groove (108) of the isolating seat (106). The sliding member (602) includes a pushing part (605) on the side closer to the L-pole trip unit (601) and a pushing part away from the L-pole trip unit (601). A protruding post (606) on one side; a sliding elastic element (607) is provided between the protruding post (606) and the isolation seat (106); a connecting rod (604) is provided in the cavity groove (608) inside the sliding element (602), and the connecting rod (604) abuts against the thermal element (603); a plug (609) is provided on the sliding element (602) at the position corresponding to the cavity groove (608), and the plug (609) is inserted into the cavity groove (608) to position and install the connecting rod (604). In the cavity groove (608); a pressing block (610) is provided on the sliding member (602) at the position of the contact part (406) of the auxiliary locking member (402); when a short circuit occurs, the L-pole trip unit (601) pushes the pushing part (605), causing the sliding member (602) to move away from the L-pole trip unit (601) in the guide groove (108), and the pressing block (610) presses against the contact part (406) and causes the auxiliary locking member (402) to rotate; when overloaded, the thermal element (603) Thermal expansion causes the connecting rod (604) and the sliding member (602) to slide toward the auxiliary locking member (402), so that the pressing block (610) presses against the contact part (406) to drive the auxiliary locking member (402) to rotate; a partition (109) is provided on the isolation seat (106) above the sliding member (602), the sliding member (602) is positioned between the isolation seat (106) and the partition (109), and the sliding member (602) can slide in the guide groove (108).

10. The electromagnetic circuit breaker according to claim 2, characterized in that, It also includes an overtravel compensation mechanism, which includes a contact link (301), a shaft (302), and a contact elastic element (303); one end of the contact link (301) is connected to the contact support (200), and the other end is connected to the contact insertion hole (304) of the moving contact (300); a transverse strip hole (305) is provided on the moving contact (300) at the position corresponding to the shaft (302), and the strip hole (305) is slidably engaged with the shaft (302); a protrusion (306) is provided on the moving contact (300) between the contact insertion hole (304) and the strip hole (305); a receiving groove (112) is provided on the isolation seat (106) and / or the bottom shell (101) at the position corresponding to the moving contact (300); the contact elastic element (303) is provided in the receiving groove (112) and the protrusion (306). Between 306); when the moving contact (300) contacts the stationary contact (307), the contact elastic element (303) is compressed, and a relative displacement is generated between the strip hole (305) and the insertion shaft (302) to achieve overtravel compensation; there are two moving contacts (300), namely an L-pole moving contact (300) and an N-pole moving contact (300). The contact connecting rod (301) of the L-pole moving contact (300) is connected in the insertion hole (206) of the contact frame body (202), and the contact connecting rod (301) of the N-pole moving contact (300) is connected in the insertion hole (206) of the contact frame base (203); the isolation seat (106) and the bottom shell (101) are provided with receiving grooves (112) corresponding to the L-pole moving contact (300) and the N-pole moving contact (300).

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