An excitation fuse without a pre-break

Abstract

The application discloses a pre-breakage-free excitation fuse, which comprises a shell, an excitation source, a piston, a fuse assembly, a first conductive body structure and a second conductive body structure; the first conductive body structure and the second conductive body structure are arranged in an insulating and spaced mode on the inner wall of the shell in the displacement direction of the piston; the fuse assembly is provided with an electrically-conductive outer cap at two ends; in an initial position, the outer cap of one end of the fuse assembly is in electrically-conductive contact with the first conductive body structure and the second conductive body structure to form a series circuit; when the excitation source drives the fuse assembly to displace from the initial position to a terminal position, the series circuit is disconnected, and the fuse is melted and broken after being connected in series with the first conductive body structure and the second conductive body structure. The excitation fuse has no pre-breakage and is connected with the fuse assembly before being disconnected, so that the breaking capacity and arc extinguishing capacity are improved.

Description

Technical Field

[0001] This invention relates to the field of circuit protection, particularly to circuit protection in the fields of power control and new energy vehicles, specifically to excitation fuses used for circuit protection. Background Technology

[0002] Fuses are generally used for circuit protection. When an overload current or short-circuit current occurs, the fuse breaks, thus disconnecting the circuit and providing protection. Driven fuses are currently the fastest-responding circuit protection devices. Driven fuses typically consist of a drive source, a piston, and a conductor bus. In use, the conductor bus is connected in series in the protection circuit. When an overload current, short-circuit current, or certain pre-set abnormal conditions occur in the circuit (such as a collision involving a new energy vehicle or a fire, requiring immediate circuit disconnection for protection), the drive source activates based on the received trigger signal, releasing high-pressure gas as the driving force to displace the piston. This displacement of the piston cuts off the conductor bus. To facilitate the disconnection of the conductor bus, a pre-break is usually provided. The piston impacts the pre-break, disconnecting the conductor bus at the pre-break point. While excitation fuses offer fast response times, they also have several drawbacks: The kinetic energy required for the piston to break the conductor busbar is extremely high, necessitating a sufficiently powerful propellant explosion (high-pressure gas) from the excitation source. Otherwise, the piston cannot provide enough kinetic energy to break the busbar. Furthermore, a sufficiently powerful explosion of the excitation source causes significant impact on the fuse's casing, requiring high mechanical strength. In certain situations, protective sleeves are needed around the excitation source and piston to enhance impact resistance. Simultaneously, because breaking the busbar requires substantial kinetic energy, and the propellant power (high-pressure gas) released by the excitation source diminishes over time, failure to break the busbar will cause the entire excitation fuse to malfunction. Finally, the pre-break size of the busbar is critical. A large pre-break size drastically increases the energy required to break the busbar, potentially preventing it from breaking. Conversely, a small pre-break size makes the busbar fragile and prone to spontaneous disconnection under vibration or other conditions. Summary of the Invention

[0003] The purpose of this invention is to provide an excitation fuse without pre-break, which does not require breaking the conductor busbar. It only requires the displacement of the fuse assembly set in the fuse housing to achieve the connection and disconnection between the two terminals of the excitation fuse. At the same time, the fuse assembly is connected to the disconnected circuit to extinguish the arc.

[0004] To achieve the above objectives, the present invention provides a pre-break excitation fuse, comprising a shell with a hollow portion, an excitation source, a fuse assembly, a first conductor structure, and a second conductor structure;

[0005] The first conductive structure and the second conductive structure are disposed in the housing with an insulating gap between them. One end of the first conductive structure and the second conductive structure located in the housing is a conductive contact end, and the other end of the first conductive structure and the second conductive structure serves as the connection end of the excitation fuse for connecting to an external circuit.

[0006] The fuse assembly is disposed in the hollow part of the housing and includes an insulating fuse housing, a conductive outer cap, a fusible element, and an arc-extinguishing medium. The outer caps are respectively fitted and fixed on the outer periphery of both ends of the fuse housing. The arc-extinguishing medium is filled in the fuse housing. The fusible element is disposed in the arc-extinguishing medium. The two ends of the fusible element are respectively electrically connected to the outer caps at both ends of the fuse housing.

[0007] The outer cap at one end of the fuse assembly makes conductive contact with the conductive contact ends of the first conductor structure and the second conductor structure to form a series circuit.

[0008] The excitation source is fixedly disposed relative to or disposed on the housing, and the chamber where the end of the excitation source that releases the driving force is located is connected to the chamber where the end of the fuse assembly that is acted upon by the driving force is located.

[0009] When an abnormal situation occurs, the excitation source acts according to the received trigger signal, releases the driving force, and drives the fuse assembly to move from the initial position to the termination position. As the fuse assembly moves, the relative positional relationship between the fusible element and the first and second conductive structures changes. At the same time, the series circuit is broken, and the fusible element is connected in series between the first and second conductive structures, establishing insulation between the conductive contact ends of the first and second conductive structures on the outer periphery of the fuse assembly, and the fusible element melts.

[0010] Preferably, in the initial state, when the outer cap at the other end of the fuse assembly is not in conductive contact with the first conductor structure and the second conductor structure, the fusible element is not conductive with the series circuit; when the fuse assembly is displaced, the fusible element is first connected in parallel with the series circuit, and the series circuit is disconnected so that the fusible element is connected in series between the first conductor structure and the second conductor structure.

[0011] In the initial state, when the outer cap at the other end of the fuse assembly makes conductive contact with one of the first conductor structure and the second conductor structure, the fusible element is connected in parallel with the series circuit; when the fuse assembly is displaced, the series circuit is broken, so that the fusible element is connected in series between the first conductor structure and the second conductor structure.

[0012] Preferably, the conductive contact ends of the first conductor structure and the second conductor structure located in the housing are respectively configured as cylindrical structures. The conductive contact end of the first conductor structure is a cylindrical structure with both ends through, and the conductive contact end of the second conductor structure is a cylindrical structure. The end of the conductive contact end of the second conductor structure facing the first conductor structure is an open end so that one end of the fuse assembly can pass through.

[0013] Preferably, the end of the conductive contact terminal of the second conductor structure that is away from the first conductor structure is a closed end, and the closed end is disposed against one end of the outer shell.

[0014] Preferably, conductive spring fingers are nested on the inner wall of the cylindrical structure of the conductive contact end of the first conductor structure and the second conductor structure or on the outer peripheral surface of the outer cap of the fuse assembly. When the outer caps at both ends of the fuse assembly contact the conductive contact end, the spring fingers abut against the outer cap and the conductive contact end respectively.

[0015] Preferably, the connecting end of the first conductor structure passes through the outer shell in the radial direction and is located outside the outer shell, and the end of the connecting end of the second conductor structure that passes through the outer shell in the axial direction is located outside the outer shell.

[0016] Preferably, an insulating ring structure protruding from the outer peripheral surface of the fuse housing is provided on the outer peripheral surface between the two ends of the fuse housing. The outer caps at both ends of the fuse assembly are located on both sides of the insulating ring structure. The outer caps and the outer peripheral surface of the insulating ring structure form a complete and smooth outer peripheral surface of the fuse assembly.

[0017] Preferably, at least one sealing ring is provided on the inner wall of the housing between the conductive contact ends of the first conductor structure and the second conductor structure; or, when the fuse assembly is displaced to the termination position, at least one sealing ring is provided on the outer peripheral surface of the fuse assembly corresponding to the inner wall of the housing between the conductive contact ends of the first conductor structure and the second conductor structure.

[0018] Preferably, in the initial position, an insulating distance is maintained between the outer cap of the fuse assembly, in which the first conductor structure and the second conductor structure are insulated from each other, and the conductive contact end.

[0019] Preferably, the fuse assembly further includes a conductive inner cap, which is fixedly disposed at both ends of the fuse housing. The inner cap is located between the end of the fuse housing and the outer cap, and the inner cap is in conductive contact with the outer cap. Both ends of the fusible element are conductively connected to the inner cap.

[0020] Preferably, one end of the excitation source that releases the driving force is directly corresponding to or corresponds through the air passage to the end of the fuse assembly that is acted upon by the driving force. In the initial position, the end of the fuse assembly that is acted upon by the driving force is the other end opposite to the end that is in contact with both the first conductor structure and the second conductor structure.

[0021] Preferably, it further includes a piston, with one end of the excitation source that releases the driving force directly corresponding to or corresponding to the piston through the air passage, and the piston corresponding to the fuse assembly; when the excitation source releases the driving force, it drives the piston to move, and the piston displacement drives the fuse assembly to move from the initial position to the final position.

[0022] Preferably, a sealing ring is provided at the contact surface between the piston and the inner wall of the outer casing.

[0023] Preferably, the outer shell is assembled from segmented shell structures, and the segmented shell structures are connected and fixed by one or both of screws or threads.

[0024] Preferably, in the piston displacement direction, the outer casing includes an excitation source housing, a first housing, a second housing, and a third housing sequentially assembled; the excitation source is disposed in the excitation source housing and closes the end of the excitation source housing away from the first housing; the piston is disposed in the first housing; the first conductor structure is nested in the second housing from the end of the second housing toward the first housing, and the connecting end of the first conductor structure passes through the contact surface between the first housing and the second housing; the end of the third housing away from the second housing is a closed end, the second conductor structure is nested into the third housing from the open end of the third housing, and the connecting end of the second conductor structure passes through the closed end of the third housing.

[0025] Preferably, threaded holes for connection are provided on the outer peripheral surfaces of the excitation source housing, the first housing, the second housing, and the third housing, and the excitation source housing is connected to the first housing by screws passing through the corresponding threaded holes; the first housing, the second housing, and the third housing are connected and fixed by screws passing through the corresponding threaded holes; the second housing and the third housing are connected and fixed by screws passing through the corresponding threaded holes.

[0026] The excitation fuse of this invention uses high-pressure gas released from an excitation source to drive a piston displacement. The kinetic energy of the piston displacement drives the fuse assembly to slide within the excitation fuse housing. The fuse assembly is initially connected to the main circuit in parallel. Then, as the fuse assembly displaces, the main circuit is disconnected, forming a series connection between the fuse assembly and the main circuit. Current is limited by the fuse assembly, and the main circuit is completely disconnected by the melting of the fuse element. Arc extinguishing is achieved by the arc-extinguishing medium inside the fuse assembly. The structural design of this invention eliminates the need for a pre-break in the excitation fuse and positions the generated arc inside the fuse assembly, thus improving both breaking capacity and arc-extinguishing capability.

[0027] Because the sliding friction between the fuse assembly and the inner wall of the housing is very small when the fuse assembly slides along the housing, the small amount of propellant (high-pressure gas) released by the excitation source can drive the fuse assembly to slide. Therefore, the impact force on the housing and internal components when the excitation source is activated is much smaller than the impact force when the existing conductor is disconnected, which reduces the mechanical strength requirements of the housing and eliminates the need for additional components to improve impact resistance.

[0028] The structure of the conductor bus has been changed. By altering the structural relationship between the fuse assembly and the two terminal structures, the action process of conduction-connection of the fusible element-fusible element melting and arc extinguishing is realized. There is no need to reserve space for the piston to disconnect the conductor bus, the displacement space after the conductor bus is disconnected, or the accommodating space for the arc extinguishing fusible element, making the structure more compact and smaller in size.

[0029] Under normal operating conditions, the fuse assembly is not connected to the main circuit. It is only connected to the main circuit when the protection is disconnected, thus reducing power consumption. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure that activates the fuse when the fuse assembly is in its initial position.

[0031] Figure 2 This is a schematic diagram of the structure when the fuse assembly is connected between the first conductive structure and the second conductive structure.

[0032] Figure 3 This is a schematic diagram of the fuse assembly in the terminated position.

[0033] Figure 4 This is a schematic diagram of the structure that triggers the explosion of a fuse.

[0034] Figure 5 This is a schematic diagram of the exploded structure of a fuse assembly.

[0035] Figure 6 This is a schematic diagram of the external structure of the screw connection of the fuse housing.

[0036] Figure 7This is a schematic diagram of the screw connection for activating the fuse housing.

[0037] Figure Labels

[0038] 2. Excitation source, 3. Piston, 4. First conductor structure, 5. Second conductor structure, 6. Fuse assembly, 7. Fuse housing, 8. Inner cap, 9. First outer cap, 10. Second outer cap, 11. Fusible element, 12. Arc extinguishing medium, 13. Spring contact finger, 14. Sealing ring, 15. Excitation source housing, 16. First housing, 17. Second housing, 18. Screw, 19. Conductive contact end (41, 51), connection end (42, 52), insulating ring structure 71. Detailed Implementation

[0039] The pre-break-free excitation fuse of the present invention includes a housing with a hollow portion, an excitation source, a fuse assembly, a first conductor structure, and a second conductor structure;

[0040] The first conductor structure and the second conductor structure are disposed in the outer shell with an insulating gap between them. One end of the first conductor structure and the second conductor structure located in the outer shell is a conductive contact end, and the other end of the first conductor structure and the second conductor structure serves as a connection end for activating the fuse to connect to the external circuit.

[0041] The fuse assembly is installed in the hollow part of the housing. It includes an insulating fuse housing, a conductive outer cap, a fusible element, and an arc-extinguishing medium. The outer caps are respectively fitted and fixed on the outer periphery of both ends of the fuse housing. The arc-extinguishing medium is filled in the fuse housing. The fusible element is installed in the arc-extinguishing medium. The two ends of the fusible element are electrically connected to the outer caps at both ends of the fuse housing.

[0042] The outer cap at one end of the fuse assembly makes conductive contact with the conductive contact ends of the first conductor structure and the second conductor structure to form a series circuit.

[0043] The excitation source is fixed relative to the housing or mounted on the housing, and the chamber where the excitation source releases the driving force is located is connected to the chamber where the fuse assembly is acted upon by the driving force.

[0044] When an abnormal situation occurs, the excitation source acts according to the received trigger signal, releases the driving force, and drives the fuse assembly to move from the initial position to the termination position. As the fuse assembly moves, the relative positional relationship between the fusible element and the first and second conductive structures changes. At the same time, the series circuit is broken, and the fusible element is connected in series between the first and second conductive structures. Insulation is established between the conductive contact ends of the first and second conductive structures on the outer periphery of the fuse assembly, and the fusible element melts.

[0045] 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.

[0046] The pre-break induced fuse of the present invention, see [link / reference]. Figures 1 to 4 It includes a housing, an excitation source 2, a piston 3, a first conductor structure 4, a second conductor structure 5, and a fuse assembly 6. Wherein:

[0047] The outer casing is a tubular structure made of insulating material, with a hollow section within it serving as a linear displacement channel. The casing is closed at both ends, with an excitation source 2 and a piston 3 located at one end. The excitation source 2 is a gas generating device that reacts to a received trigger signal, igniting and exploding to generate a large amount of high-pressure gas as the driving force. The piston 3 is located within the hollow section of the casing. The cavity at the end of the excitation source 2 that releases the high-pressure gas is connected to the cavity at the end of the piston facing the excitation source 2. The signal receiving end of the excitation source 2 is located outside the casing and can receive trigger signals from outside the excitation fuse. Figures 1 to 3 In the process, one end of the high-pressure gas from the excitation source 2 is positioned directly opposite the piston 3. The piston 3 is in sealed contact with the inner wall of the hollow part. To achieve this sealed contact, a sealing ring 14 is provided on the outer circumferential surface of the piston 3. The sealing ring is located between the piston 3 and the inner wall of the hollow part of the outer shell, thus achieving a contact seal between the piston 3 and the inner wall of the hollow part of the outer shell. At the same time, the initial position of the piston 3 is limited by the elastic compression of the sealing ring between the piston 3 and the inner wall of the hollow part of the outer shell.

[0048] Along the displacement path of piston 3 and in the hollow portion of the outer casing in front of the displacement path, a first conductive structure 4 and a second conductive structure 5 are provided at intervals and insulatedly. One end of the first conductive structure 4 and the second conductive structure 5 located in the outer casing are conductive contact ends (41, 51), and the other end of one end of the first conductive structure 4 and the second conductive structure 5 passes through the outer casing and is located outside the outer casing, serving as connection ends (42, 52) for activating the fuse.

[0049] The conductive contact ends (41, 51) of the first conductor structure 4 and the second conductor structure 5 are spaced apart and insulatedly nested on the inner wall of the hollow part of the shell, and are flush with the surface of the inner wall of the hollow part. The surface shape of the conductive contact ends (41, 51) flush with the surface of the inner wall of the hollow part of the shell is exactly the same as the surface shape of the inner wall of the hollow part of the shell. The surface shape of the conductive contact ends (41, 51) flush with the surface of the inner wall of the hollow part of the shell forms a complete and smooth displacement channel for the fuse assembly to slide. In this embodiment, the conductive contact ends (41, 51) are cylindrical structures, and the shape of their inner wall is the same as the shape of the inner wall surface of the hollow part of the outer shell. The conductive contact end 41 is a cylindrical structure with both ends through it. The connecting end 42 is located in the radial direction of the excitation fuse and is integrally connected to one end face of the conductive contact end 41, passing through the outer shell and located in the outer shell of the excitation fuse. The conductive contact end 51 is a cylindrical structure with one end open and one end closed. The end facing the conductive contact end 41 is the open end, and the closed end away from the conductive contact end 41 is set against the end face of the outer shell of the excitation fuse away from the piston 3. The connecting end 52 is located at the end face of the closed end of the conductive contact end 51, and the end that passes through the outer shell of the excitation fuse is located outside the outer shell. When one end of the conductive contact 51 is set as a closed end, it can buffer the impact energy caused by the displacement of the fuse assembly. At the same time, it improves the overall resistance of the excitation fuse to the impact caused by the displacement of the fuse assembly and improves the safety performance of the excitation fuse housing. Of course, when the excitation fuse housing has sufficient strength, the conductive contact 51 may not be set as a closed end, and the excitation fuse housing can bear the impact energy of the fuse assembly. The conductive contact (41, 51) does not have to be a cylindrical structure, but only a part of a cylindrical structure.

[0050] A fuse assembly 6 is disposed along the displacement path of the piston 3 in the hollow portion of the outer casing. Driven by the piston 3, the fuse assembly 6 can slide along the hollow portion of the outer casing. (See also...) Figure 5The fuse assembly 6 includes a fuse housing 7, an inner cap 8, a first outer cap 9, a second outer cap 10, and a fusible element 11. The fuse housing 7 is the outer shell of the fuse assembly, a tubular structure extending through both ends, made of insulating material. A ring-shaped insulating ring structure 71 protruding from the outer circumference of the fuse housing 7 is provided. Inner caps 8 are provided at both ends of the fuse housing 7. First outer caps 9 and second outer caps 10 are provided at the ends of the fuse housing 7 where the inner caps are located, respectively, to seal the ends of the fuse housing 7. The inner cap 8 is in conductive contact with the first outer cap 9 and the second outer cap 10. The opposite ends of the first outer cap 9 and the second outer cap 10 abut against the two sides of the insulating ring structure 71. The outer circumferential surfaces of the first outer cap 9, the second outer cap 10, and the insulating ring structure 71 form a complete, smooth outer circumferential surface of the fuse assembly that can linearly displace along the hollow portion of the fuse housing. The inner cap 8 is made of conductive material. The first outer cap 9 and the second outer cap 10 are both made entirely or partially of conductive material. Regardless of whether the fuse assembly 6 is displaced, the conductive portion of the outer cap of the fuse assembly 6 can make conductive contact with the first conductive structure 4 and the second conductive structure 5. The length of the second outer cap 10 is much greater than the length of the first outer cap 9. Both ends of the fusible element 11 are fixedly connected to the inner cap 8, so that both ends of the fusible element 11 are conductively connected to the inner cap 8, the first outer cap 9, and the second outer cap 10, respectively. The fuse housing 7 is filled with an arc-extinguishing medium 12, and the fusible element 11 passes through the arc-extinguishing medium 12. A narrow neck can be provided on the fusible element 11, located within the arc-extinguishing medium 12. The resistance value of the fusible element 11 is much greater than the resistance values ​​of the first outer cap 9, the inner cap 8, the second outer cap 10, the first conductive structure 4, and the second conductive structure 5. The above-mentioned fuse assembly includes an inner cap 8. In some embodiments, the inner cap 8 may not be provided, and both ends of the fusible element are directly conductively connected to the outer cap.

[0051] The first outer cap 9 of the fuse assembly 6 is positioned towards the piston 3, while the second outer cap 10 is positioned away from the piston 3. In the initial position, the first outer cap 9 is located between the conductive contact end 41 of the first conductive structure 4 and the piston 3, maintaining an insulating distance between the first outer cap 9 and the conductive contact end 41 of the first conductive structure 4 and the conductive contact end 51 of the second conductive structure 5. The two ends of the second outer cap 10 are located at the conductive contact ends (41, 51) of the first conductive structure 4 and the second conductive structure 5, respectively, forming a series circuit with the conductive contact ends (41, 51). In the initial position, the first outer cap 9 is not in contact with the series circuit. To enhance conductive contact performance, at least one conductive spring finger 13 is nested at intervals on the inner surfaces of the conductive contact ends (41, 51) of the first conductive structure 4 and the second conductive structure 5. The spring finger 13 is a conductive spring coil with a certain elasticity in the radial direction. In the initial position, the spring finger 13 is in a compressed state between the second outer cap 10 and the conductive contact end face (41, 51), respectively abutting against the second outer cap 10 and the conductive contact end (41, 51), ensuring reliable contact between the second outer cap 10 and the conductive contact end (41, 51). In the final position, the first outer cap 9 and the second outer cap 10 abut against the spring finger at the conductive contact end (41, 51). In some embodiments, the spring finger may also be nested on the outer peripheral surface of the outer cap at both ends of the fuse assembly. Whether the spring contact is located on the inner surface of the conductive structure or on the outer circumference of the outer cap, using a spring contact helps to make the contact between the conductive structure and the outer cap more stable and the conductivity more reliable. When the conductive structure is cylindrical, using a spring contact results in more uniform force distribution and better conductivity.

[0052] The purpose of setting the spring contact finger 13 is to improve the reliable contact between the outer cap and the conductive structure. Alternatively, the spring contact finger 13 can be omitted, as long as the outer cap and the conductive structure can achieve reliable conductive contact.

[0053] In the initial position, the circuit for activating the fuse itself is a series circuit consisting of the first conductive structure 4, the second outer cap 10, and the second conductive structure 5 connected in series. That is, under normal operating conditions, current flows through the series circuit of the first conductive structure 4, the second outer cap 10, and the second conductive structure 5, and the fuse element 11 in the fuse assembly 6 is not connected to the main circuit. At least one sealing ring 14 is provided on the inner wall of the outer casing between the conductive contact end 41 and the conductive contact end 51 along the piston displacement direction. During the displacement of the fuse assembly 6 to the termination position, after the second outer cap 10 disengages from the conductive contact end 51 of the second conductive structure 5, the inner wall of the insulating outer casing between the fuse assembly's outer casing and the outer casing is contacted by the insulating ring structure 71 of the fuse assembly and the conductive contact end 41 of the first conductive structure 4 and the conductive contact end 51 of the second conductive structure 5. Insulation is established between the first outer cap 9 and the first conductive structure 4, and between the second outer cap 10 and the second conductive structure 5. To improve insulation performance, a sealing ring 14 at the inner wall of the outer casing between the first conductive structure 4 and the second conductive structure 5 creates a sealed contact between the insulating ring structure 71 and the inner wall of the outer casing, achieving complete insulation. In some embodiments, the sealing ring 14 may also be disposed on the outer circumferential surface of the insulating ring structure 71 of the fuse assembly. When the sealing ring 14 is disposed on the outer circumferential surface of the insulating ring structure 71, preferably, the spring contact finger is disposed on the outer circumference of the outer cap of the fuse assembly. The purpose of this arrangement is to prevent interference between the spring contact finger and the sealing ring 14 when the fuse assembly is displaced. In design, it is preferable that the spring contact finger and the sealing ring do not interfere with each other.

[0054] The casing of the trigger fuse can be assembled from multiple casing sections, see [link / reference] Figures 1 to 7The outer shell is assembled from an excitation source shell 5, a first shell 16, a second shell 17, and a second shell 18, and is fixedly connected by screws. Limiting structures, such as concave-convex structures, are provided at the mating surfaces of the excitation source shell 5, the first shell 16, the second shell 17, and the second shell 18. A groove is provided on one end face of the shell, and a protrusion is provided on the other mating end face. During mating, the protrusion engages with the groove to form a limiting structure, preventing relative sliding between the two shells. The excitation source 2 is located within the excitation source shell 5, and the end of the excitation source shell 5 away from the first shell 16 is closed. The first shell 16 is a tubular structure with both ends open; initially, the piston 3 is located within the first shell 16. The second housing 17 is a tubular structure extending through both ends. A receiving groove is provided in the end of the second housing 17 facing the first housing 16 to accommodate the conductive contact end 41 of the first conductive structure 4. An insulating distance is maintained between the bottom of the receiving groove and the end of the second housing 17 facing the third housing 18. At least one sealing ring 14 is provided on the inner wall of the second housing 17 between the bottom of the receiving groove and the end of the second housing 17 facing the third housing 18. A notch is provided at the end face of the second housing 17 facing the first housing 16 for the connection end 42 of the first conductive structure 4 to pass through. The conductive contact end 41 of the first conductive structure 4, with a spring-loaded finger 13, is nested into the receiving groove of the second housing 17 from the end facing the first housing 16. The third housing 18 is a tubular structure open at one end and closed at the other. The open end faces the second housing 17, and the closed end has a through hole for the connection end 52 of the second conductive structure 5 to pass through. The conductive contact end 51 of the second conductor structure 5 is nested into the hollow part of the third housing 18. The connecting end 52 of the third conductive bus structure 5 passes through the through hole on the closed end of the third housing 18 and is located outside the outer shell, thus sealing the through hole on the closed end of the third housing 18. The segmented shell structure of the outer shell facilitates the assembly of the excitation source 2, piston 3, first conductor structure 4, second conductor structure 5 and fuse assembly 6, reducing assembly difficulty.

[0055] The outer shell, formed by assembling segmented shell structures, is connected by screws 19 and nuts. (See attached image.) Figure 6 Each housing has threaded holes for connection on its outer periphery. Excitation source housing 15 and first housing 16 are connected and fixed by screws 19 and nuts. First housing 16, second housing 17 and third housing 18 are connected and fixed by screws. Since the termination position of fuse assembly 6 is located at the end of the conductive contact end 51 of the second conductor structure 5 in the third housing away from the piston 3, it will bring a certain impact force to the third housing. Therefore, in order to improve the impact resistance of the third housing 18, the second housing 17 and the third housing 18 are connected and fixed by screws.

[0056] The segmented housing structure can be connected by screws, threads, or a combination of screws and threads. Threaded connections can reduce the size of the activated fuse.

[0057] In some embodiments, in order to improve the impact resistance of the fuse assembly 6, the thickness of the end face of the closed end of the second outer cap 10 is increased.

[0058] Working principle:

[0059] In the initial position, the first outer cap 9 of the fuse assembly 6 is located between the conductive contact end 41 of the first conductive structure 4 and the piston 3, and an insulating distance is maintained between it and the conductive contact end 41 of the first conductive structure 4. The formed circuit is a series circuit in which the first conductive structure 4, the second outer cap 10, and the third conductive bus structure 5 are connected in series. The fuse assembly 6 is not connected to the main circuit being protected.

[0060] Under normal operating conditions, the current in the main circuit flows through the series circuit formed by the first conductor structure 4, the second outer cap 10, and the third conductor bus structure 5 connected in series. (See attached diagram.) Figure 1 As shown.

[0061] When an abnormal situation occurs (such as overload current, short circuit current, or collision requiring immediate disconnection of the main circuit), the excitation source 2 activates according to the trigger signal, releasing high-pressure gas as a driving force to drive the piston 3 to move. The piston 3 then drives the fuse assembly 6 to move, causing the first outer cap 9 and the second outer cap 10 to simultaneously make conductive contact with the first conductive structure 4. At this time, the series circuit formed by the first conductive structure 4, the second outer cap 10, and the third conductive bus structure 5 remains conductive. Simultaneously, the fuse assembly 6 is connected to the main circuit in parallel, forming an arc-extinguishing circuit that is connected in parallel with the main circuit and in series with the first conductive structure 4, the first outer cap 9, the inner cap 8, the fuse 11, the inner cap 8, the second outer cap 10, and the second conductive structure 5. (See [link]). Figure 2 As shown, the first conductor structure 4, the fuse assembly 6, and the second conductor structure 5 are connected in series to form an arc-extinguishing circuit in parallel with the main circuit, and the fuse assembly 6 is introduced into the main circuit in parallel.

[0062] As the fuse assembly 6 continues to move, the second outer cap 10 disengages from the conductive contact end 41 of the first conductive structure 4, breaking the series circuit formed by the first conductive structure 4, the second outer cap 10, and the second conductive structure 5. The main circuit current flows through the arc-extinguishing circuit formed by the first conductive structure 4, the fuse assembly 6, and the second conductive structure 5 connected in series. Since the resistance of the fuse element 11 of the fuse assembly 6 is much greater than the resistance of the second outer cap 10, the current flowing through the arc-extinguishing circuit is reduced by a factor of two, thus limiting the current through the fuse assembly 6. At the same time, after the second outer cap 10 disengages from the first conductive busbar 4, an insulating barrier is established between the first outer cap 9 and the first conductive structure 4, and between the second outer cap 10 and the second conductive structure 5. As the fuse assembly 6 continues to move to the termination position, the fuse element 11 of the fuse assembly 6 melts, and the generated arc is enclosed within the housing of the fuse assembly 6 and extinguished by the arc-extinguishing medium.

[0063] After the second outer cap 10 loses its conductive contact with the conductive contact end 41 of the first conductive bar 4, the insulating ring structure 71 on the outer peripheral surface of the fuse assembly 6 begins to contact the inner wall of the fuse housing between the first conductive structure 4 and the second conductive structure 5, and seals the contact surface between the insulating ring structure 71 and the inner wall of the housing through the sealing ring 14, thereby establishing an insulating isolation between the first conductive structure 4 and the second conductive structure 5, and between the first outer cap and the second outer cap on the outer periphery of the fuse assembly 6.

[0064] During the initial position, displacement process and termination position of the fuse assembly 6, under the elastic force of the spring contact finger 13, reliable conductive contact is ensured between the spring contact finger 13 at the first conductive structure 4 and the second conductive structure and the first outer cap 9 and the second outer cap 10, thereby ensuring reliable contact between the first outer cap 9 and the second outer cap 10 and the first conductive structure 4 and the second conductive structure.

[0065] Since the conductive contact end 51 of the second conductor structure is a closed structure at one end, when the fuse assembly 6 reaches the termination position, that is, when the fuse assembly 6 contacts the conductive contact end 51, the fuse assembly 6 stops displacing. The closed end of the conductive contact end 51 directly bears the impact caused by the displacement of the fuse assembly 6. Since the second conductor structure 5 is made of metal, its impact resistance is higher, further improving the safety performance of the fuse housing.

[0066] In the above embodiments, a piston is provided. In some embodiments, a piston may not be provided. In the initial position, the excitation source directly corresponds to, or through the air passage corresponds to, the end of the fuse assembly that is not in contact with both the first and second conductor structures. The driving force released by the excitation source acts on the end of the fuse assembly that is not in contact with both the first and second conductor structures, driving the fuse assembly to move. With a piston, the displacement of the fuse assembly can be better controlled, resulting in higher operational reliability. Moreover, by setting a piston, the driving force released by the excitation source is prevented from directly acting on the fuse assembly, avoiding direct impact on the fuse assembly, the first conductor structure, etc., thus improving the operational safety of the fuse assembly.

[0067] Regardless of whether a piston is provided or not, the cavity containing the end of the excitation source that releases the driving force is connected to the fuse assembly or the cavity containing the piston that is acted upon by the driving force. This connection can be direct or through an air passage. In the case of direct connection, the end of the excitation source that releases the driving force can be directly positioned corresponding to the piston or fuse assembly, or it can be positioned corresponding to the piston or fuse assembly through an air passage provided on the housing. The driving force released by the excitation source directly drives the piston or fuse assembly to displacement, or it drives the piston or fuse assembly to displacement through the air passage.

[0068] exist Figure 1 In the initial state, the first outer cap 9 of the fuse assembly is not in contact with either the first or second conductive structure. The second outer cap 10 is in contact with the first conductive structure 4 and the second conductive structure 5, forming a series circuit in which the first conductive structure 4, the second outer cap 10, and the second conductive structure 5 are connected in series. The fuse assembly is neither connected in parallel nor in series with this series circuit. In some embodiments, in the initial state, the fuse assembly can be connected in parallel with the series circuit in which the first conductive structure, the second outer cap, and the second conductive structure are connected in series. See also Figure 7 The first outer cap 9 of the fuse assembly is in conductive contact with the first conductive structure 4, and the second outer cap 10 is in conductive contact with the first conductive structure 4 and the second conductive structure 5 respectively. The second outer cap 10 forms a series circuit with the first conductive structure 4 and the second conductive structure 5. The fuse assembly is also connected in parallel with the series circuit formed between the second outer cap 10 and the first conductive structure 4 and the second conductive structure 5.

[0069] When an abnormal situation occurs (such as overload current, short circuit current, or collision requiring immediate disconnection of the main circuit), the excitation source 2 operates according to the trigger signal, releasing high-pressure gas as a driving force to drive the piston 3 to move. The piston 3 then drives the fuse assembly 6 to move. During the process of the fuse assembly 6 moving from the initial position to the final position, the first outer cap 9 of the fuse assembly 6 is always in conductive contact with the first conductive structure 5, while the second outer cap 10 changes from being in conductive contact with both the first conductive structure 4 and the second conductive structure 5 to being in conductive contact only with the second conductive structure 5. This breaks the series circuit formed by the second outer cap 10, the first conductive structure 4, and the second conductive structure 5, and connects the fuse assembly in series with the first conductive structure 4 and the second conductive structure 5, causing the fuse element of the fuse assembly to melt.

Claims

1. An excitation fuse without pre-break, characterized in that, It includes a hollow shell, an excitation source, a fuse assembly, a first conductor structure, and a second conductor structure; The first conductive structure and the second conductive structure are disposed in the housing with an insulating gap between them. One end of the first conductive structure and the second conductive structure located in the housing is a conductive contact end, and the other end of the first conductive structure and the second conductive structure serves as the connection end of the excitation fuse for connecting to an external circuit. The fuse assembly is disposed in the hollow part of the housing and includes an insulating fuse housing, a conductive outer cap, a fusible element, and an arc-extinguishing medium. The outer caps are respectively fitted and fixed on the outer periphery of both ends of the fuse housing. The arc-extinguishing medium is filled in the fuse housing. The fusible element is disposed in the arc-extinguishing medium. The two ends of the fusible element are respectively electrically connected to the outer caps at both ends of the fuse housing. The outer cap at one end of the fuse assembly makes conductive contact with the conductive contact ends of the first conductor structure and the second conductor structure to form a series circuit. The excitation source is fixedly disposed relative to or disposed on the housing, and the chamber where the end of the excitation source that releases the driving force is located is connected to the chamber where the end of the fuse assembly that is acted upon by the driving force is located. When an abnormal situation occurs, the excitation source acts according to the received trigger signal, releases the driving force, and drives the fuse assembly to move from the initial position to the termination position. As the fuse assembly moves, the relative positional relationship between the fusible element and the first and second conductive structures changes. At the same time, the series circuit is broken, and the fusible element is connected in series between the first and second conductive structures, establishing insulation between the conductive contact ends of the first and second conductive structures on the outer periphery of the fuse assembly, and the fusible element melts.

2. The excitation fuse according to claim 1, characterized in that, In the initial state, when the outer cap at the other end of the fuse assembly is not in conductive contact with the first conductor structure and the second conductor structure, the fusible element is not conductive with the series circuit; when the fuse assembly is displaced, the fusible element is first connected in parallel with the series circuit, and the series circuit is disconnected so that the fusible element is connected in series between the first conductor structure and the second conductor structure. In the initial state, when the outer cap at the other end of the fuse assembly makes conductive contact with one of the first conductor structure and the second conductor structure, the fusible element is connected in parallel with the series circuit; when the fuse assembly is displaced, the series circuit is broken, so that the fusible element is connected in series between the first conductor structure and the second conductor structure.

3. The excitation fuse according to claim 2, characterized in that, The conductive contact ends of the first conductor structure and the second conductor structure located in the housing are respectively configured as cylindrical structures. The conductive contact end of the first conductor structure is a cylindrical structure with both ends open, and the conductive contact end of the second conductor structure is a cylindrical structure. The end of the conductive contact end of the second conductor structure facing the first conductor structure is an open end, so that one end of the fuse assembly can pass through.

4. The excitation fuse according to claim 3, characterized in that, The end of the conductive contact terminal of the second conductor structure that is away from the first conductor structure is a closed end, and the closed end is disposed against one end of the outer shell.

5. The excitation fuse according to claim 3, characterized in that, Conductive spring fingers are nested on the inner wall of the cylindrical structure of the conductive contact end of the first conductor structure and the second conductor structure or on the outer peripheral surface of the outer cap of the fuse assembly. When the outer caps at both ends of the fuse assembly come into contact with the conductive contact end, the spring fingers abut against the outer cap and the conductive contact end respectively.

6. The excitation fuse according to claim 3, characterized in that, The connecting end of the first conductor structure passes through the outer shell in the radial direction and is located outside the outer shell, while the connecting end of the second conductor structure passes through the outer shell in the axial direction and is located outside the outer shell.

7. The excitation fuse according to claim 1, characterized in that, An insulating ring structure, protruding from the outer peripheral surface of the fuse housing, is provided on the outer peripheral surface between the two ends of the fuse housing. The outer caps at both ends of the fuse assembly are located on both sides of the insulating ring structure. The outer caps and the outer peripheral surface of the insulating ring structure form a complete and smooth outer peripheral surface of the fuse assembly.

8. The excitation fuse according to claim 1, characterized in that, At least one sealing ring is provided on the inner wall of the housing between the conductive contact ends of the first conductor structure and the second conductor structure; or, when the fuse assembly is displaced to the termination position, at least one sealing ring is provided on the outer peripheral surface of the fuse assembly corresponding to the inner wall of the housing between the conductive contact ends of the first conductor structure and the second conductor structure.

9. The excitation fuse according to claim 1, characterized in that, In the initial position, an insulating distance is maintained between the outer cap of the fuse assembly and the conductive contact end, where the first and second conductor structures are insulated from each other.

10. The excitation fuse according to claim 1, characterized in that, The fuse assembly also includes a conductive inner cap, which is fixedly disposed at both ends of the fuse housing. The inner cap is located between the end of the fuse housing and the outer cap, and the inner cap is in conductive contact with the outer cap. Both ends of the fusible element are conductively connected to the inner cap.

11. The excitation fuse according to claim 1, characterized in that, The end of the excitation source that releases the driving force is directly corresponding to or corresponds through the air passage to the end of the fuse assembly that is acted upon by the driving force. In the initial position, the end of the fuse assembly that is acted upon by the driving force is the other end opposite to the end that is in contact with both the first conductor structure and the second conductor structure.

12. The excitation fuse according to claim 11, characterized in that, It also includes a piston, with one end of the excitation source that releases driving force directly corresponding to or corresponding to the piston through an air passage, and the piston corresponding to the fuse assembly; when the excitation source releases driving force, it drives the piston to move, and the piston displacement drives the fuse assembly to move from the initial position to the final position.

13. The excitation fuse according to claim 12, characterized in that, A sealing ring is provided at the contact surface between the piston and the inner wall of the outer casing.

14. The excitation fuse according to claim 1, characterized in that, The outer shell is assembled from segmented shell structures, which are connected and fixed by one or both of screws or threads.

15. The excitation fuse according to claim 14, characterized in that, In the piston displacement direction, the outer shell includes an excitation source shell, a first shell, a second shell, and a third shell sequentially assembled; the excitation source is disposed in the excitation source shell and closes the end of the excitation source shell away from the first shell; the piston is disposed in the first shell; the first conductor structure is nested in the second shell from the end of the second shell toward the first shell, and the connecting end of the first conductor structure passes through the contact surface between the first shell and the second shell; the end of the third shell away from the second shell is a closed end, the second conductor structure is nested into the third shell from the open end of the third shell, and the connecting end of the second conductor structure passes through the closed end of the third shell.

16. The excitation fuse according to claim 15, characterized in that, The outer peripheral surfaces of the excitation source housing, the first housing, the second housing, and the third housing are respectively provided with threaded holes for connection. The excitation source housing is connected to the first housing by screws passing through the corresponding threaded holes. The first housing, the second housing, and the third housing are connected and fixed by screws passing through the corresponding threaded holes. The second housing and the third housing are connected and fixed by screws passing through the corresponding threaded holes.

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