Short-circuit current tolerance structure of direct-current contactor

Abstract

A short-circuit current tolerance structure of a direct current contactor comprises a push rod and a movable contact bridge structure, the movable contact bridge structure comprises a horizontal supporting piece, supporting frames, an upper magnetizer, a lower magnetizer, a movable contact bridge and a contact bridge spring, the supporting frames are arranged on the two opposite sides of the horizontal supporting piece, a limiting structure is arranged at one end of each supporting frame, and the upper magnetizer is clamped in the limiting structure; in the displacement direction of the push rod, the upper magnetizer can move relative to the limiting structure in the limiting structure; a contact bridge spring, a lower magnetizer and a movable contact bridge are sequentially arranged among the horizontal supporting piece, the upper magnetizer and the supporting frame, the movable contact bridge is fixedly arranged on the lower magnetizer, the movable contact bridge abuts against the upper magnetizer in the switching-off position, the upper magnetizer moves towards the movable contact bridge in the limiting structure in the switching-on position, and under the action of magnetic force, the upper magnetizer moves towards the movable contact bridge in the limiting structure. And a gap between the upper magnetizer and the lower magnetizer after closing is reduced. The supporting frame is connected through the displaceable upper magnetizer, the number of parts is reduced, the structure is simplified, and assembling is convenient.

Description

Technical Field

[0001] This invention relates to the field of high voltage DC technology, and in particular to a DC contactor that can improve short-circuit current withstand capability. Background Technology

[0002] A high-voltage DC contactor is a switching device that needs to frequently switch DC circuits on and off. In new energy applications, such as pure electric vehicles, high-voltage DC contactors are typically used to connect and disconnect the power battery system. When the contact bridge is connected to the stationary contact, the current flowing through it generates an electro-repulsive force (including Lorentz force and Holm force), which tends to separate the contact bridge from the stationary contact. When a short-circuit fault occurs in the power battery system, a short-circuit current exceeding tens of times the rated current will be generated. The contact bridge will be subjected to an extremely large electro-repulsive force, causing it to spring away from the stationary contact, generating an electric arc, leading to contactor failure, or even an explosion.

[0003] Existing technology uses two magnetic conductors made of soft magnetic material mounted above and below the contact bridge. When current flows through, the soft magnetic materials are magnetized and attract each other. Because the upper magnetic conductor is fixed, the lower magnetic conductor is attracted upwards, providing a compensating force to prevent the contact bridge from springing open. The larger the current, the greater the compensating force. However, this solution typically has two implementation schemes. The first scheme has a very small initial air gap between the upper and lower magnetic conductors when the contact bridge and stationary contact are not connected. When the contact bridge and stationary contact are connected, the final air gap between the upper and lower magnetic conductors equals the initial air gap plus overtravel. According to electromagnetic principles, the mutual attraction between the upper and lower magnetic conductors decreases as the air gap increases. This scheme does not fully utilize the magnetic force of the upper and lower magnetic conductors. The second scheme has the upper magnetic conductor completely fixed. When the contact bridge and stationary contact are connected, the final air gap between the upper and lower magnetic conductors is a fixed value, which can solve the problem of insufficient magnetic force utilization. However, this requires additional parts and assembly steps. Furthermore, when the contact bridge and stationary contact are ablated and material is lost, this fixed value will be reduced, affecting product performance. Summary of the Invention

[0004] The purpose of this invention is to provide a DC contactor that, by changing the frame structure of the moving contact bridge, makes the end of the support frame facing the stationary contact open, and by having the upper magnetic conductor engaged in a limiting structure at the open end of the support frame, changes the air gap distance between the upper and lower magnetic conductors during closing and opening. When closing, the air gap distance is reduced, thereby improving the electromagnetic compensation force and thus enhancing the short-term withstand capability of the contactor. Furthermore, this invention does not add any extra parts and is easy to assemble.

[0005] To achieve the above objectives, the present invention provides a short-circuit current withstand structure for a DC contactor, comprising a push rod and a moving contact bridge structure. The moving contact bridge structure is fixedly disposed at the end of the push rod. The moving contact bridge structure includes a horizontal support member, a support frame, an upper magnetic conductor, a lower magnetic conductor, a moving contact bridge, and a contact bridge spring. The horizontal support member is fixedly disposed at one end of the push rod. Support frames protruding from the horizontal support member are respectively disposed on opposite sides of the horizontal support member, and a limiting structure is provided at one end of the support frame away from the horizontal support member. The upper magnetic conductor is respectively engaged in the limiting structure on opposite sides. The upper magnetic conductor can be displaced relative to the limiting structure within the limiting structure. A contact bridge spring, a lower magnetic conductor, and a movable contact bridge are sequentially arranged between the horizontal support member, the upper magnetic conductor, and the support frame, starting from the direction of the horizontal support member. The movable contact bridge is fixedly mounted on the lower magnetic conductor. The contact bridge spring supports the lower magnetic conductor and the movable contact bridge. In the open position, the movable contact bridge abuts against the upper magnetic conductor. In the closed position, the movable contact bridge disengages from the upper magnetic conductor, and the upper magnetic conductor displaces within the limiting structure towards the movable contact bridge. Under magnetic force, the gap between the upper and lower magnetic conductors is reduced after the circuit is closed.

[0006] Preferably, in the direction of push rod displacement, the displacement distance of the upper conductor magnet in the limiting structure is less than the distance between the open and closed positions of the moving contact bridge.

[0007] Preferably, the limiting structure is a limiting notch, a limiting hole, or a limiting groove, and a protrusion structure is provided at corresponding positions on opposite sides of the upper magnetic conductor corresponding to the limiting structure. The protrusion structure is engaged in the limiting structure. In the direction of push rod displacement, the thickness of the protrusion structure is less than the height of the limiting structure, so that the protrusion structure of the upper magnetic conductor can be displaced in the limiting structure.

[0008] Preferably, the support frame is a plate-like structure, and one end of the support frame with the limiting structure is elastic.

[0009] Preferably, the support frame portion between the limiting structure and the horizontal support member is bent outwards towards the push rod to form a bent structure, which absorbs the deformation of the support frame during the interference fit of the upper conductor magnet.

[0010] Preferably, the limiting structure is a limiting notch provided on opposite sides of the support frame, and the upper magnetic conductor is provided with a positioning groove at the position of the support frame between the two limiting notches, and the protrusion structure is formed on opposite sides of the positioning groove; the support frame portion between the two limiting notches is located in the positioning groove of the upper magnetic conductor, and the protrusion structure on opposite sides of the positioning groove is engaged in the limiting notch of the support frame.

[0011] Preferably, the support frame portion between the two limiting notches is bent toward the inside of the push rod and abuts against the side of the upper magnetic conductor, so that the upper magnetic conductor is clamped between the two support frames.

[0012] Preferably, the end of the support frame away from the horizontal support member is bent at an angle of less than 90 degrees from the connection point with the limiting structure toward the outside of the push rod.

[0013] Preferably, the sides of the support frame between the bending structure and the limiting structure respectively abut against the lower magnetic conductor to define the position of the lower magnetic conductor.

[0014] Preferably, the support frame includes two branch frames arranged at relative intervals, and the limiting notches are respectively provided at corresponding positions on opposite sides of the two branch frames to form the limiting structure. The upper conductor magnet is provided with a protrusion structure on the side corresponding to the limiting structure, and the protrusion structure is engaged in the limiting notches of the two branch frames.

[0015] Preferably, the two branch frames between the limiting notch and the horizontal support are bent in opposite directions to form a bending structure, which can absorb the deformation of the support frame caused by the interference fit of the upper conductor magnet.

[0016] Preferably, the support frame has limiting notches at corresponding positions on both sides to form the limiting structure, and a deep groove is formed at the center of the support frame portion between the two limiting notches, the deep groove penetrating the thickness of the support frame and the end away from the horizontal support member; the upper magnetic conductor is provided with a positioning groove at the support frame position between the two limiting notches, and protrusion structures are formed on the opposite sides of the positioning groove; the support frame portion between the two limiting notches is located in the positioning groove of the upper magnetic conductor, and the protrusion structures on the opposite sides of the positioning groove are engaged in the limiting notches of the support frame.

[0017] Preferably, the side of the limiting notch away from the horizontal support is configured as an inclined structure to facilitate the assembly of the upper magnet.

[0018] The short-circuit current withstand structure of the DC contactor of the present invention is achieved by setting the ends of the two support frames away from the push rod as spaced-apart open structures, with the upper magnetic conductor positioned between the two support frames. The upper magnetic conductor connects the two support frames, and the position of the upper magnetic conductor is limited by the limiting structure of the support frames. Simultaneously, the displacement gap between the limiting structure and the upper magnetic conductor ensures that the upper magnetic conductor can move relative to the limiting structure when the contactor is opened and closed. When closing, the air gap between the upper and lower magnetic conductors is reduced, increasing the electromagnetic compensation force after closing, thereby improving the short-circuit current withstand capability of the DC contactor. By cooperating with the limiting structure on the two support frames of the open structure, the upper magnetic conductor can be displaced, simplifying the number of components and structure, and making assembly easier.

[0019] Meanwhile, by changing the structural form of the support frame, such as by using a bending structure to absorb the deformation of the support frame during the interference fit of the upper magnet, the support frame is ensured to maintain elastic deformation after interference fit; the inclined structure on one side of the limiting notch facilitates assembly; and the bending design of the support frame between the two limiting notches abuts against the upper magnet, forming a clamping and positioning of the upper magnet. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the contactor structure with the outer casing removed.

[0021] Figure 2 This is a schematic diagram of the moving contact bridge structure in the open state.

[0022] Figure 3 yes Figure 2 A schematic diagram of the explosion structure.

[0023] Figure 4 This is a schematic diagram of the moving contact bridge structure after the circuit is closed.

[0024] Figure 5 yes Figure 2 A cross-sectional structural diagram.

[0025] Figure 6 This is a schematic diagram of a structure with a flat, plate-like supporting frame.

[0026] Figure 7 This is a structural diagram of the supporting frame, which includes two branch frames.

[0027] Figure label:

[0028] Electromagnetic drive mechanism 10, push rod 11, stationary contact 12, horizontal support 13, support frame 14, upper magnetic conductor 15, lower magnetic conductor 16, moving contact bridge 17, contact bridge spring 18, limiting notch 20, bending structure 21, first limiting feature 22, positioning groove 23, deep groove 24, branch frame 25, protrusion structure 26. Detailed Implementation

[0029] The short-circuit current withstand structure of the DC contactor of the present invention includes a push rod and a moving contact bridge structure, the moving contact bridge structure being fixedly disposed at the end of the push rod; the moving contact bridge structure includes a horizontal support member, a support frame, an upper magnetic conductor, a lower magnetic conductor, a moving contact bridge, and a contact bridge spring. The horizontal support member is fixedly disposed at one end of the push rod, and support frames protruding from the horizontal support member are respectively provided on opposite sides of the horizontal support member, and a limit structure is provided at the end of the support frame away from the horizontal support member. The upper magnetic conductor is respectively engaged in the limit structure on opposite sides, and the movement of the push rod... In the direction of the limit structure, the upper magnetic conductor can be displaced relative to the limit structure. Between the horizontal support, the upper magnetic conductor, and the support frame, a contact bridge spring, a lower magnetic conductor, and a moving contact bridge are arranged sequentially from the direction of the horizontal support. The moving contact bridge is fixedly mounted on the lower magnetic conductor. The contact bridge spring supports the lower magnetic conductor and the moving contact bridge. When the circuit is open, the moving contact bridge abuts against the upper magnetic conductor. When the circuit is closed, the moving contact bridge disengages from the upper magnetic conductor, and the upper magnetic conductor displaces towards the moving contact bridge within the limit structure. Under the action of magnetic force, the gap between the upper and lower magnetic conductors is reduced after the circuit is closed.

[0030] The following describes preferred embodiments in detail with reference to the accompanying drawings. The directional terms used are for reference only and do not constitute a limitation on the technical solutions of this invention.

[0031] See Figures 1 to 5 The present invention provides a high-voltage DC contactor with improved short-circuit current withstand capability, comprising an electromagnetic drive mechanism 10, a push rod 11, a stationary contact 12, and a moving contact bridge structure.

[0032] The electromagnetic drive mechanism 10 includes an electromagnetic coil and a moving iron core. A push rod 11 is fixedly connected to the moving iron core, and the push rod 11 is driven to make linear displacement by the electromagnetic drive mechanism 10. A moving contact bridge structure is fixedly provided at the end of the push rod 11 facing the stationary contact 12.

[0033] The moving contact bridge structure includes a horizontal support 13, a support frame 14, an upper magnetic conductor 15, a lower magnetic conductor 16, a moving contact bridge 17, and a contact bridge spring 18. The horizontal support 13 is fixedly mounted on the end of the push rod 11. The support frame 14 is fixedly connected to opposite sides of the horizontal support 13. The support frame 14 is a bent plate-like structure. The support frame 14 can be made of metal or insulating material. The support frame 14 and the horizontal support 13 can be independent components or integrally molded. When it is made of metal, it is integrally injection molded with the horizontal support 13.

[0034] A horizontal support member 13 protrudes from the support frame 14 toward the stationary contact 12. Limiting notches 20 are provided on opposite sides of the support frame 14 to form a limiting structure. The portion of the support frame 14 between the two limiting notches 20 bends toward the other side of the support frame 14, i.e., bends toward the inside of the push rod. The portion of the support frame fixedly connected between the limiting notch 20 and the horizontal support member 13 forms an outward bending structure 21, i.e., the bending structure 21 bends toward the outside of the push rod. The bending structure 21 is U-shaped or a V-shaped structure with a flat bottom. The side of the bending structure 21 facing the stationary contact 12 is a vertical flat plate structure. The end of the support frame 14 on the side of the limiting notch 20 facing the stationary contact 12 bends outward at an angle of less than 90 degrees to form a first limiting feature 22. The bent end of the support frame 14 toward the stationary contact 12 has a certain degree of elasticity.

[0035] The upper magnetic conductor 15 has positioning grooves 23 on both sides, and protrusion structures are formed on one side of the upper magnetic conductor 15 on both sides of the positioning grooves 23. During assembly, the upper magnetic conductor 15 is assembled from the end where the stationary contact is located between the support frames 14 on both sides of the horizontal support member 13. The limiting notches 20 on both sides of the support frame 14 are located in the positioning grooves of the upper magnetic conductor 15. The protrusion structures on both sides of the positioning grooves 23 of the upper magnetic conductor 15 are respectively engaged in the limiting notches 20 of the support frame 14. In the direction of push rod displacement, the thickness of the protrusion structure of the upper magnetic conductor 15 is less than the height of the limiting notch 20 to ensure that the upper magnetic conductor can be displaced in the height direction of the limiting notch 20 in the direction of push rod displacement. The displacement distance of the upper magnetic conductor in the limiting structure (i.e., the limiting notch 20) is less than the distance between the open and closed positions of the moving contact bridge. The bent support frame portion between the two limiting notches of the support frame 14 abuts against the side of the upper magnetic conductor 15 at the positioning groove 23. When the upper magnetic conductor 15 is assembled onto the support frame 14 through the openings at both ends of the two support frames 14, the bending structure 21 of the support frame 14 can absorb the interference deformation during assembly. The upper magnetic conductor 15 is positioned by the locking structure at the end of the support frame 14 engaging with the positioning groove of the upper magnetic conductor 15, and further secured by the first limiting feature 22 of the bending at the end of the support frame 14, thus preventing left, right, front, and back positioning. The first limiting feature 22 of the bending at the ends of the two support frames 14 forms a trumpet-shaped opening at the ends of the two support frames, facilitating the pressing and installation of the upper magnetic conductor 15 through the openings of the two support frames 14. To further facilitate the installation of the upper magnetic conductor 15, the outer periphery of the end of the upper magnetic conductor 15 facing the moving contact bridge is rounded or chamfered.

[0036] Between the upper magnetic conductor 15, the horizontal support member 13, and the two support frames 14, starting from the direction of the horizontal support member 13, a contact bridge spring 18, a lower magnetic conductor 16, and a movable contact bridge 17 are arranged sequentially. The lower magnetic conductor 16 has a U-shaped structure and is located between the two support frames 14. The position of the lower magnetic conductor 16 is limited by the vertical flat plate structure between the bending structure 21 of the support frame and the limiting notch 20. The movable contact bridge 17 is placed in the U-shaped groove of the lower magnetic conductor 16. One end of the contact bridge spring 18 is nested on the horizontal support member 13, and the other end of the contact bridge spring 18 abuts against the bottom of the lower magnetic conductor 16. The movable contact bridge 17 is located on the lower magnetic conductor 15. The contact bridge spring 18 causes the movable contact bridge 17 to contact the upper magnetic conductor 15. In the open position, under the action of the contact bridge spring 18, the moving contact bridge 17 abuts against the upper magnetic conductor 15, causing the upper magnetic conductor 15 to abut against the side of the limiting notch 20 facing the stationary contact 12, with a displacement gap maintained between the upper magnetic conductor 15 and the side of the limiting notch 20 away from the stationary contact; when the moving contact bridge and the stationary contact are closed, the push rod moves towards the stationary contact, the stationary contact 12 abuts against the moving contact bridge 17, and the moving contact bridge 17 and the lower magnetic conductor 16 compress the contact bridge spring 18 under the contact of the stationary contact 12, causing the moving contact bridge 17 to disengage from the contact of the upper magnetic conductor 15 and move away from the upper magnetic conductor 15; since an electric repulsive force is generated when the moving contact bridge and the stationary contact are closed, under the action of the electric repulsive force, the moving contact bridge 17 moves away from the stationary contact 12, making the contact unreliable; at the same time, when closing, the upper magnetic conductor 15 and the lower magnetic conductor 16... 6. Magnetic forces attract each other. Under the combined effect of the attraction force of the lower magnetic conductor 16 and the gravity of the upper magnetic conductor 15, the upper magnetic conductor 15, which is in contact with the moving contact bridge, moves towards the moving contact bridge in the limiting notch 20. Due to the position limitation of the limiting notch 20, the upper magnetic conductor 15 stops moving when it reaches the side of the limiting notch 20 facing the moving contact bridge. Under the magnetic attraction force of the upper magnetic conductor 15, the lower magnetic conductor 16, which is moving away from the stationary contact under the electric repulsion force, moves the moving contact bridge 17 towards the upper magnetic conductor 15, reducing the gap between the upper magnetic conductor 15 and the lower magnetic conductor 16. Through the magnetic attraction force of the upper magnetic conductor 15 on the lower magnetic conductor 16, a holding force is formed on the contact system after closing, overcoming the electric repulsion force during closing, so that the moving contact bridge 17 and the stationary contact 12 maintain reliable contact. The limiting notch 20 not only facilitates the assembly and positioning of the upper conductor magnet 15, but also limits the initial position and the position of the upper conductor magnet 15 after closing through the two sides of the limiting notch 20.

[0037] Moreover, when the moving contact bridge structure comes into contact with the stationary contact, the first limiting feature at the end of the support frame 14 comes into contact with the top of the contactor housing. Due to the elasticity of the first limiting feature, the moving contact bridge structure is buffered when the circuit is closed.

[0038] In this embodiment, the upper magnetic conductor has a certain displacement distance in the limiting structure. In the initial stage of closing, under the action of the stationary contact and the electric repulsion, the moving contact bridge and the lower magnetic conductor move away from the upper magnetic conductor, making the gap between the upper and lower magnetic conductors the largest. During the closing process until the closing is stable, under the action of magnetic attraction, the upper magnetic conductor attracts the lower magnetic conductor to move towards the upper magnetic conductor, reducing the distance between the upper and lower magnetic conductors. Until the closing position is stable, the upper and lower magnetic conductors maintain the minimum distance after closing, ensuring that the moving contact bridge structure has sufficient electromagnetic compensation force to counteract the electric repulsion after closing, and improving the ability to withstand short-circuit current.

[0039] In other embodiments, see Figure 6 The support frame 14 is a flat plate structure. Limiting notches 20 are provided at corresponding positions on opposite sides of the support frame 14. A deep groove 24 is formed between the two limiting notches 20, penetrating the thickness of the support frame 14 and the end of the support frame facing the stationary contact, so that the two limiting notches 20 on both sides of the support frame 14 are located on opposite sides of the deep groove 24. The end of the support frame 14 facing the stationary contact 12 on the side of the limiting notch 20 is designed with a beveled structure for easy assembly. During assembly, the end of the support frame 14 facing the stationary contact 12 is inserted into the positioning groove 23 of the upper magnetic conductor 15. Because the portions of the deep groove 24 with limiting notches on opposite sides have a certain degree of elasticity, irreversible deformation will not occur when it is interference-fitted into the positioning groove. After insertion, the protrusions on opposite sides of the positioning groove 23 of the upper magnetic conductor 15 are respectively engaged in the limiting notches 20. In the direction of push rod displacement, the thickness of the upper magnetic conductor 15 is less than the height of the limiting notch 20.

[0040] In other embodiments, see Figure 7 The horizontal support member 13 has two branch frames 25 arranged at intervals on opposite sides. Limiting notches 20 are provided on opposite sides of the two branch frames 25 near the stationary contact to form a limiting structure. The support frame portion facing the stationary contact from the limiting notch 20 has a beveled structure for easy assembly. The two branch frames 25 between the limiting notch 20 and the horizontal support member 13 are bent in opposite directions to form an arc-shaped bending structure. Protrusion structures 26 are provided on opposite sides of the upper magnetic conductor 15 at the positions corresponding to the limiting notches 20. The protrusion structures on opposite sides of the upper magnetic conductor 15 are engaged in the two limiting notches 20 of the two branch frames 25, providing assembly positioning for the upper magnetic conductor 15. The thickness of the upper magnetic conductor 15 is less than the height of the limiting notch 20. When the upper magnetic conductor 15 is assembled to the limiting notch 20 of the branch frame, the arc-shaped bending structure can absorb the interference deformation of the branch frame during assembly.

[0041] In the moving contact bridge structure of this invention, the ends of two support frames on opposite sides of the horizontal support member facing the stationary contact are open. The upper magnetic conductor is inserted between the two support frames through the open ends using an interference fit, and then engages with the limiting structure in a locking manner to achieve assembly. During assembly, the deformation generated during the interference fit is absorbed by the elasticity of the support frames themselves or by the bending structure of the support frames. The limiting structure, such as a limiting notch, limiting hole, or limiting groove, is provided at the end of the support frame facing the stationary contact. The upper magnetic conductor is equipped with protrusions that can engage with the limiting notch, limiting hole, or limiting groove corresponding to the limiting structure of the support frame. For example, a groove is provided on one side of the upper magnetic conductor, and protrusions are formed on the opposite sides of the groove. Figure 1 , Figure 7 The upper conductor magnet structure in the middle.

Claims

1. A short-circuit current resistance structure of a DC contactor, characterized by, The device includes a push rod and a movable contact bridge structure, the movable contact bridge structure being fixedly mounted on the end of the push rod. The movable contact bridge structure includes a horizontal support member, a support frame, an upper magnetic conductor, a lower magnetic conductor, a movable contact bridge, and a contact bridge spring. The horizontal support member is fixedly mounted on one end of the push rod. Support frames protruding from the horizontal support member are respectively provided on opposite sides of the horizontal support member, and a limiting structure is provided at one end of the support frame away from the horizontal support member. The upper magnetic conductor is respectively engaged in the limiting structure on opposite sides. In the direction of push rod displacement, the upper magnetic conductor can be positioned within the limiting structure. The relative displacement of the limiting structure; between the horizontal support, the upper magnetic conductor, and the support frame, a contact bridge spring, a lower magnetic conductor, and a movable contact bridge are sequentially arranged from the direction of the horizontal support. The movable contact bridge is fixedly arranged on the lower magnetic conductor. The contact bridge spring supports the lower magnetic conductor and the movable contact bridge. When the circuit is open, the movable contact bridge abuts against the upper magnetic conductor. When the circuit is closed, the movable contact bridge disengages from the upper magnetic conductor, and the upper magnetic conductor displaces within the limiting structure toward the movable contact bridge. Under the action of magnetic force, the gap between the upper magnetic conductor and the lower magnetic conductor is reduced after the circuit is closed.

2. The short circuit current resistant structure of claim 1, wherein, In the direction of the push rod displacement, the displacement distance of the upper conductor magnet in the limiting structure is less than the distance between the open and closed positions of the moving contact bridge.

3. The short circuit current tolerant structure of claim 2, wherein, The limiting structure is a limiting notch, limiting hole, or limiting groove. A protrusion structure is provided at corresponding positions on both sides of the upper magnetic conductor corresponding to the limiting structure. The protrusion structure is engaged in the limiting structure. In the direction of push rod displacement, the thickness of the protrusion structure is less than the height of the limiting structure, so that the protrusion structure of the upper magnetic conductor can be displaced in the limiting structure.

4. The short circuit current tolerant structure of claim 3, wherein, The support frame is a plate-like structure, and one end of the support frame with the limiting structure is elastic.

5. The short circuit current tolerant structure of claim 4, wherein, The support frame portion between the limiting structure and the horizontal support member is bent outwards towards the push rod to form a bending structure. The bending structure absorbs the deformation of the support frame when the upper conductor magnet is interference-fitted.

6. The short circuit current tolerant structure of claim 4, wherein, The limiting structure is a limiting notch provided on opposite sides of the support frame. The upper magnetic conductor is provided with a positioning groove at the position of the support frame between the two limiting notches, and the protrusion structure is formed on opposite sides of the positioning groove. The support frame portion between the two limiting notches is located in the positioning groove of the upper magnetic conductor, and the protrusion structure on opposite sides of the positioning groove is engaged in the limiting notch of the support frame.

7. The short-circuit current withstand structure according to claim 5, characterized in that, The support frame portion between the two limiting notches is bent toward the inside of the push rod and abuts against the side of the upper magnet, so that the upper magnet is clamped between the two support frames.

8. The short-circuit current withstand structure according to claim 5, characterized in that, The end of the support frame away from the horizontal support member is bent at an angle of less than 90 degrees from the connection point with the limiting structure toward the outside of the push rod.

9. The short-circuit current withstand structure according to claim 5, characterized in that, The sides of the support frame between the bending structure and the limiting structure respectively abut against the lower magnetic conductor, thereby defining the position of the lower magnetic conductor.

10. The short-circuit current withstand structure according to claim 4, characterized in that, The support frame includes two branch frames that are spaced apart from each other. The limiting notches are respectively provided at corresponding positions on the opposite sides of the two branch frames to form the limiting structure. The upper magnet is provided with a protrusion structure on the side corresponding to the limiting structure. The protrusion structure is engaged in the limiting notches of the two branch frames.

11. The short-circuit current withstand structure according to claim 10, characterized in that, The two branch frames between the limiting notch and the horizontal support are bent in opposite directions to form a bending structure. The bending structure can absorb the deformation of the support frame caused by the interference fit of the upper conductor magnet.

12. The short-circuit current withstand structure according to claim 4, characterized in that, The support frame has limiting notches at corresponding positions on both sides to form the limiting structure. A deep groove is formed at the center of the support frame portion between the two limiting notches, and the deep groove extends through the thickness of the support frame and to the end away from the horizontal support member. The upper magnetic conductor is provided with a positioning groove at the support frame position between the two limiting notches, and protrusion structures are formed on both sides of the positioning groove. The support frame portion between the two limiting notches is located in the positioning groove of the upper magnetic conductor, and the protrusion structures on both sides of the positioning groove are engaged in the limiting notches of the support frame.

13. The short-circuit current withstand structure according to claim 10 or 12, characterized in that, The side of the limiting notch away from the horizontal support is configured as an inclined structure to facilitate the assembly of the upper magnet.

Images