Excitation fuse structure

Abstract

The utility model relates to the field of circuit protection, in particular to an excitation fuse structure which comprises a first shell, a conductor assembly and a second shell which are spliced in sequence, an excitation source and a piston are located in the first shell, and the piston is arranged corresponding to a conductor of the conductor assembly; the second shell is of an integrally-formed structure with one end open and the other end closed, and the open end of the second shell is arranged in the direction of the conductor assembly. A fuse structure is integrated in the second shell, the fuse body is arranged in the fuse structure in a penetrating manner and is conductively connected in parallel with the conductor in the conductive assembly, and the fuse body disconnecting assembly is arranged in the fuse structure; when the excitation source acts to release the driving force, the piston is driven to move, and after the piston disconnects the conductor of the conductor assembly, the melt disconnecting assembly is pushed to disconnect the melt. According to the invention, except the conductive part, other parts are all integrally injection-molded, so that the insulating property of the fuse is improved, and the influence of the fuse on the insulation and voltage resistance of the peripheral environment is reduced to zero.

Description

Technical Field

[0001] The present invention relates to the field of circuit protection, especially to the circuit protection in new energy vehicles, power fields, etc., and specifically to an excitation fuse structure for circuit protection. Background Art

[0002] As a protection device in a circuit system, various electronic components are arranged around the fuse. Considering safety and usage, the insulation withstand voltage requirements between components are relatively high. At the beginning of the development of excitation fuses, it was difficult to overcome the strength problems of the explosion chamber and the arc extinguishing chamber. Therefore, some metals were added around the plastic housing as protection to increase the strength. For example, a single-break excitation fuse disclosed in Chinese Patent 2021226828004 has a gland installed on the outer periphery of the housing where the excitation source is installed, and moreover, it is composed of multiple housings, with a large number of parts. Although such products also meet the requirements according to the designed insulation withstand voltage distance, considering the complexity of some electronic components during operation, it is necessary to streamline the peripheral structure of the excitation fuse to further improve the insulation performance. Summary of the Invention

[0003] The purpose of the present invention is to provide an excitation fuse structure. Through the first housing, conductor assembly, second housing, fuse cover, guide member, and piston integrally injection-molded, all parts except the conductive parts achieve a fully plasticized integral structure, improving the insulation performance of the excitation fuse and reducing the influence of the excitation fuse on the insulation withstand voltage of the peripheral environment to zero. At the same time, through the integral structure parts, the number of parts is reduced, and the assembly efficiency is improved.

[0004] To achieve the above purpose, the technical solution provided by the present invention is an excitation fuse structure, including a first housing, a conductor assembly, a second housing, an excitation source, a piston, a melt disconnection assembly, and a melt; the first housing, the conductor assembly, and the second housing are spliced, the conductor assembly is located between the first housing and the second housing, the excitation source and the piston are located in the first housing, and the piston corresponds to the conductor of the conductor assembly;

[0005] The second housing is an integrally formed structure with one end open and one end closed, and the open end of the second housing is arranged towards the direction of the conductor assembly; a fuse structure is integrated in the second housing, the melt is threaded through the fuse structure and electrically connected in parallel with the conductor in the conductive assembly, and the melt disconnection assembly is arranged in the fuse structure;

[0006] When the excitation source acts to release driving force, driving the piston to displace, after the piston disconnects the conductor of the conductor assembly, it pushes the melt disconnection assembly to disconnect the melt.

[0007] Preferably, the fuse structure includes a spliced fuse cover and a guide member. The fuse cover is disposed at the open end of the second housing, and the guide member is located at the bottom of the second housing. Displacement channels penetrating the fuse structure are respectively formed in the fuse cover and the guide member along the piston displacement path, and the fuse element passes through the displacement channels. The fuse element disconnection assembly is disposed in the displacement channels, and the initial position of the fuse element disconnection assembly is defined by the fuse cover and the guide member. A sealed arc extinguishing chamber is formed among the fuse element disconnection assembly, the second housing, the fuse cover and the guide member, and an arc extinguishing medium is filled in the arc extinguishing chamber.

[0008] Preferably, the fuse cover and the guide member are respectively integrally formed structures.

[0009] Preferably, the fuse cover and the guide member respectively include platforms. At corresponding positions on the end faces of the platforms of the fuse cover and the guide member that face each other and along the piston displacement path, bosses protruding from the end faces are respectively provided, and the bosses are in contact with each other. The displacement channels are located on the bosses of the fuse cover and the guide member.

[0010] Preferably, the boss of the fuse cover has a variable cross-section structure with a gradually shrinking cross-section in the direction towards the guide member. On the end faces of the bosses of the fuse cover and the guide member that face each other and on opposite sides of the displacement channel, support columns are respectively provided and extend towards each other in an abutting manner. The support column of the fuse cover and the support column of the guide member are in contact with each other.

[0011] Preferably, the fuse element disconnection assembly includes a butted pusher block and a guide block. The butting surfaces of the pusher block and the guide block are connected by an uneven structure or a hole and pin structure. The fuse element is clamped between the butting surfaces of the pusher block and the guide block.

[0012] Preferably, a limiting structure is provided between the two ends of the guide block in the displacement direction. The limiting structure is a limiting boss provided on opposite sides of the guide block, or a circumferential arc separating ring provided around the outer periphery of the guide block. A weak disconnection point is provided at the connection between the limiting structure and the guide block. The limiting structure is arranged between the bosses of the fuse cover and the guide member. In the displacement channel at the fuse cover, a limiting step is provided in the direction towards the guide member, and the limiting step presses against one end of the pusher block towards the piston direction. The initial position of the fuse element disconnection assembly is defined by the limiting step and the limiting structure.

[0013] Preferably, limiting steps are respectively arranged on the open end and the inner wall near the closed end of the second housing, and a plurality of protruding structures are arranged at intervals on the bottom inside the closed end; the fuse cover is arranged at the limiting step at the open end to close the open end of the second housing, the guiding member is arranged on the limiting step near the closed end and is in sealing contact with the inner wall of the second housing near the closed end, and a sealed arc extinguishing chamber is formed among the melt breaking assembly, the second housing, the fuse cover and the guiding member.

[0014] Preferably, a groove is formed in the outer end face of the bottom of the guiding member, and a plurality of positioning posts are arranged in the groove; a backing plate is arranged between the bottom of the guiding member and the bottom of the closed end of the second housing, the backing plate is located in the groove outside the guiding member and is supported by the protruding structure, and the positioning posts pass through the backing plate to position it; a part of the backing plate facing the displacement channel is arranged in a suspended manner.

[0015] Preferably, the conductor assembly includes an integrally formed conductive part and an insulating support part, and the support part is located between the contact surfaces of the conductor assembly with the first housing and the second housing respectively; the contact surface of the conductor assembly with the first housing is sealed and positioned through a sealing structure, and the contact surface of the conductor assembly with the second housing is positioned through a positioning structure.

[0016] Preferably, a nested sealing ring protruding from the end face is arranged on the end face of the support part facing the first housing, and the nested sealing ring is nested in the end face in contact with the first housing to form the sealing structure; the nested sealing ring is arranged around the outer periphery of the area where the conductive part of the conductor assembly needs to be disconnected.

[0017] Preferably, the piston is integrally formed and sequentially includes a sleeve part, a sealing part and a cutter head part which are integrally formed and connected; the sleeve part is located on the outer periphery of one end of the driving force release of the excitation source to support the excitation source, one end of the sealing part facing the excitation source extends obliquely outward toward the excitation source to form an elastic lip structure, the sealing part is in interference fit with the first housing through the lip structure to form a sealing contact, and the cutter head part is arranged corresponding to the conductive part of the conductor assembly.

[0018] Preferably, a reinforcing member for enhancing the mechanical strength of the first housing is embedded in the inner wall of the first housing.

[0019] For the excitation fuse of the present invention, except for the excitation source and the melt disconnection component, the first housing, the second housing, the fuse cover, the guide and the piston are integrally formed, and the conductor component is also integrally formed by insert molding. All components except the conductive part are made into a fully plasticized integral structure, which improves the insulation performance of the excitation fuse and reduces the influence of the excitation fuse on the insulation withstand voltage of the surrounding environment to zero. In addition, high-pressure explosion gas and arc extinguishing gas are generated during the operation of the excitation fuse. Further improving the sealing level of this gas will also reduce its influence on the surrounding environment during operation to zero. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic cross-sectional structure diagram of the excitation fuse of the present invention.

[0021] Figure 2 is a schematic three-dimensional structure diagram of the piston.

[0022] Figure 3 is a schematic cross-sectional structure diagram of the piston.

[0023] Figure 4 is a schematic structure diagram of the conductor component.

[0024] Figure 5 is a schematic structure diagram of the second housing, the fuse cover and the guide.

[0025] Figure 6 is a schematic structure diagram of the second housing.

[0026] Figure 7 is a schematic front structure diagram of the fuse cover.

[0027] Figure 8 is a schematic back structure diagram of the fuse cover.

[0028] Figure 9 is a schematic front structure diagram of the guide.

[0029] Figure 10 is a schematic back structure diagram of the guide.

[0030] MARKING DESCRIPTION:

[0031] The first shell 1, the reinforcement part 10, the conductor assembly 2, the conductive part 21, the support part 22, the nested sealing ring 23, the positioning column 24, the disconnection weak point 25, the second shell 3, the limiting step 31, the protruding structure 32, the positioning groove 33, the positioning column 34, the limiting step 35, the pad 36, the fuse cover 4, the boss 41, the slide 42, the accommodating groove 43, the limiting boss 44, the support column 45, the arc extinguishing medium filling hole 46, the through hole 47, the guide part 5, the platform 51, the boss 52, the displacement channel 53, the support column 54, the support wall 55, the reinforcement column 56, the excitation source 6, the piston 7, the sleeve part 70, the sealing part 71, the lip and tongue structure 711, the cutter head part 72, the limiting protrusion 73, the melt 8, the conductive sheet 81, the arc extinguishing chamber 82, the push block 91, the guide block 92, the limiting protrusion 93. DETAILED DESCRIPTION

[0032] The excitation fuse structure of the present invention comprises a first shell, a conductor assembly, a second shell, an excitation source, a piston, a fuse disconnection assembly and a fuse; the first shell, the conductor assembly and the second shell are spliced, the conductor assembly is located between the first shell and the second shell, the excitation source and the piston are located in the first shell, and the piston is arranged corresponding to the conductor of the conductor assembly;

[0033] The second shell is an integrally formed structure with one end open and the other end closed, and the open end of the second shell is arranged toward the conductor assembly; a fuse structure is integrated in the second shell, the fuse is arranged in the fuse structure and is conductively connected in parallel with the conductor in the conductive assembly, and the fuse disconnection assembly is arranged in the fuse structure;

[0034] When the excitation source is activated to release the driving force, the piston is driven to move, and after the piston disconnects the conductor of the conductor assembly, the melt disconnection assembly is pushed to disconnect the melt.

[0035] With respect to the above technical solution, a preferred embodiment is now given and specifically described in conjunction with the drawings. Figures 1 to 10 ,in:

[0036] The excitation fuse comprises a first shell 1, a conductor assembly 2, a second shell 3, a fuse cover 4, a guide 5, an excitation source 6, a piston 7, a melt 8, and a melt disconnect assembly.

[0037] See also Figure 1, the first housing 1, which is integrally formed by injection molding, has a cavity that penetrates both ends. An enhancing member 10 for enhancing the mechanical strength of the first housing 1 is embedded in the first housing 1. The material of the enhancing member 10 can be a metal material or other materials with mechanical strength. A nested ring groove and a limiting groove are formed on one end face of the first housing 1 facing the conductor assembly 2. A limiting structure is formed at one end of the cavity of the first housing 1 away from the conductor assembly 2. The excitation source 6 is installed at one end of the cavity of the first housing 1 with the limiting structure, and the excitation source 6 is limited and sealed through the limiting structure of the cavity, preventing the excitation source 6 from flying out of the first housing 1 when releasing explosive gas, and at the same time preventing the explosive gas from leaking out of the first housing.

[0038] The excitation source 6 is a gas generating device, which can act according to the received trigger signal and release explosive gas as a driving force.

[0039] The piston 7, see Figure 2 and Figure 3 , is made of insulating material and is integrally formed by injection molding. The piston 7 includes a sleeve portion 70, a sealing portion 71, and a cutter head portion 72 that are integrally formed and connected in sequence. The sleeve portion 70 is located in the central area of the sealing portion 72. The inner wall of the opening end face of the sleeve portion 70 is set as an inner inclined surface. The sleeve portion 70 completely wraps one end of the excitation source 6 where the driving force is released and contacts the excitation source 6 to form a support for the excitation source 6.

[0040] One end of the outer periphery of the sealing portion 71 provided with the sleeve portion 70 extends towards the excitation source side and inclines outward to form a lip structure 711. Limiting protrusions 73 are provided on both outer sides of the cutter head portion 71 of the piston 7 facing the conductor assembly 2, and limiting grooves are formed at positions of the first housing 1 corresponding to the limiting protrusions 73.

[0041] When the piston 1 is installed in the cavity of the first housing 1, the lip structure 711 forms an extrusion with the inner wall of the cavity of the first housing 1, causing the lip structure 711 to undergo elastic deformation, so that the lip structure 711 forms an interference fit with the inner wall of the cavity of the first housing, realizing the seal between the contact surfaces of the piston 7 and the inner wall of the cavity of the first housing 1. The limiting protrusions 73 are located at the limiting grooves of the first housing 1 to form a limitation on the initial position of the piston 7.

[0042] The conductor assembly 2, see Figure 4, including a conductive member 21 and a support member 22 integrally formed with the conductive member 21. The conductive member 21 and the support member 22 are integrally formed by insert molding. Both ends of the conductive member 21 are located outside both ends of the support member 22 and serve as connection ends for exciting the fuse. At the position of the support member 22 corresponding to the nested annular groove of the first housing, an annular nested sealing ring 23 with a hollow portion is integrally formed. The nested sealing ring 23 protrudes from the end face of the support member 22 toward the first housing 1, and both the displacement path of the piston and the portion of the conductive member 21 to be disconnected by the piston are located within the hollow portion of the nested sealing ring 23. The conductive member 21 passes through the hollow portion of the support member 22, and gaps are reserved between both sides in the width direction of the conductive member 21 and the inner wall of the hollow portion of the support member 22 to facilitate the piston 7 to disconnect the conductive member 21 at the hollow portion of the support member 22. A breakage-weakening portion 25 is provided at the conductive member 21 located in the hollow portion.

[0043] Along the length direction of the conductive member 21, through holes for the conductive sheet 81 to pass through are respectively provided on the conductive member 21 and the support member 22 on the opposite outer sides of the nested sealing ring 23. On the end face of the support member 22 facing the second housing 3, three positioning posts 24 and one positioning groove protruding from the end face are provided.

[0044] When the conductor assembly 2 is docked with the first housing 1, the nested sealing ring 23 of the conductor assembly 2 is inserted into the nested annular groove of the first housing 1 to form a sealing structure between the conductor assembly 2 and the first housing 1, realizing sealing and positioning between the contact surfaces of the conductor assembly and the first housing.

[0045] The second housing 3, see Figure 5 and Figure 6 , is made of an insulating material and is an integrally formed structure. The second housing 3 is a box-shaped closed structure with one end open. A limiting step 31 is formed at the open end of the second housing 3 for placing the fuse cover 4. The inner wall of the second housing 3 below the limiting step 31 is in an inclined surface structure with a gradually decreasing inner diameter. Several protruding structures 32 arranged at intervals are formed at the bottom of the second housing 3. On the end face of the second housing 3 where it is docked with the conductor assembly 2, corresponding to the position of the positioning post 24, a positioning groove 33 is formed, and a positioning post 34 is provided at the position corresponding to the positioning groove of the conductor assembly. After the conductor assembly 2 and the second housing 3 are docked, the positioning post 24 of the conductor assembly 2 is inserted into the positioning groove 33 at the end face of the second housing 3, and the positioning post 34 of the second housing 3 is inserted into the positioning groove of the conductor assembly 2 to form a positioning structure between the conductor assembly and the second housing, preventing horizontal displacement and being anti-fooling. A limiting step 35 is provided on the inner wall of the second housing above the protruding structure 32 for placing the guide member 5.

[0046] The fuse cover 4, see Figure 7 and Figure 8, the material is an insulating material and it is an integrally formed structure. The end face of the fuse cover 4 facing the conductor assembly 2 is a planar structure, and one end face of the fuse cover 4 facing the bottom of the second housing 3 is provided with a boss 41 with a shrinking structure protruding from the end face. A slideway 42 for the cutter head part of the piston 7 to enter is opened at the position of the fuse cover 4 corresponding to the piston 7, and the slideway 42 penetrates through the fuse cover 4 and the boss 41. A receiving groove 43 is opened at the end face of the fuse cover 4 facing the conductor assembly 2, and the slideway 42 is located in the receiving groove 43. The end face of the boss 41 of the fuse cover 4 facing the second housing 3 expands outward by a certain depth on the relative two sides of the slideway 42 to form a displacement channel for receiving the melt breaking assembly and allowing the melt breaking assembly to displace. Since the maximum outer diameter of the displacement channel is larger than the maximum outer diameter of the slideway 42, a limiting boss 44 is formed at the displacement channel and the slideway 42. When the melt breaking assembly is received in the displacement channel, the limiting boss 44 forms a certain pressing on the melt breaking assembly to position it. Support columns 45 protruding towards the bottom of the second housing 3 are respectively arranged on the relative two sides of the displacement channel at the end face of the boss 41 facing the second housing 3. A filling hole 46 for filling the arc extinguishing medium and a through hole 47 for the two ends of the melt 8 to be respectively connected are opened on the fuse cover 4 outside the slideway 42. A conductive sheet 81 is arranged in the through hole 47, the conductive sheet 81 seals the through hole 47, one end of the conductive sheet 81 facing the conductor assembly protrudes from the end face of the fuse cover, and the other end of the conductive sheet 81 is electrically connected to the end of the melt 8; a through hole for the conductive sheet 81 to pass through is opened on the conductor assembly corresponding to the conductive sheet 81, and one end of the conductive sheet 81 facing the conductor assembly passes through the through hole of the conductor assembly and is electrically connected to the conductive part, so that the melt is connected in parallel at both ends of the area where the conductive part needs to be disconnected; after filling the arc extinguishing medium, the filling hole 46 on the fuse cover is sealed by a plug.

[0047] The guide member 5, see Figure 9 and Figure 10, the material is an insulating material and the structure is an integrally formed structure. The guide member 5 includes a platform 51. A boss 52 facing the fuse cover 4 is provided at the position of the platform 51 corresponding to the displacement channel of the fuse cover. A displacement channel 53 for placing the melt breaking assembly and penetrating the guide member 5 is provided on the boss 52 corresponding to the displacement channel. On the bosses 52 on the opposite sides of the displacement channel 53, support columns 54 corresponding to the support columns 45 of the fuse cover 4 are respectively provided. The outer periphery of the platform 51 facing the bottom direction of the second housing 3 extends with a support wall 55 that can be attached to the inner wall of the second housing 3. A flat structure that can be placed on the limit step 35 of the second housing 3 is left on the platform 51 outside the support wall 55, and sealing can be carried out by means of gluing, or a ring of soft material is provided on the outer periphery of the platform 51 for sealing between the guide member and the inner wall of the second housing. A groove is provided on the end face of the platform 51 facing the bottom of the second housing within the support wall 55, and a number of positioning columns 56 are provided in the groove. A backing plate 36 is placed on the protruding structure 32 at the bottom of the second housing, and the protruding structure 32 forms a support for the backing plate 36. The material of the backing plate 36 is a metal material, and it is located between the displacement channel and the bottom of the second housing. The backing plate 36 is located in the groove of the guide member 5 facing the bottom of the second housing, and the positioning column 56 passes through the backing plate 36 to position it. The material of the backing plate 36 is a metal material, and the backing plate 36 is suspended between the bottom of the second housing through the protruding structure 32, leaving a buffer gap.

[0048] In the above embodiments, the fuse cover 4 and the guide member 5 can be integrally formed structural components respectively, which is convenient for processing and installation; when the fuse cover 4 and the guide member are integrally formed as a whole, parts can be saved and the assembly process can be reduced.

[0049] The melt-disconnecting component includes a butt-jointed pusher block 91 and a guiding block 92. The pusher block 91 and the guiding block 92 are connected by a pin-hole structure. The melt 8 passes through and is clamped between the contact surfaces of the pusher block 91 and the guiding block 92. The butt-jointed surfaces of the pusher block 91 and the guiding block 92 can also be a matching concave-convex structure, and the melt is clamped between the concave-convex structures at the butt-joint of the pusher block and the guiding block. A limiting structure is provided between the two ends in the displacement direction of the guiding block. The limiting structure is that limiting bumps 93 are provided on the opposite sides of the guiding block 92, and the connection between the limiting bumps 93 and the guiding block 92 is set as a breakage-weak part with reduced mechanical strength. For example, a groove structure is provided at the connection between the limiting bumps 93 and the guiding block 92, which is convenient for the guiding block 92 to break away from the limiting bumps 93 at the breakage-weak part when being driven. The pusher block 91 of the melt-disconnecting component can be arranged in the displacement channel of the fuse cover 4, and the guiding block 92 is arranged in the displacement channel 53 of the guiding member. The limiting bumps 93 of the guiding block 92 are placed on the boss 52 of the guiding member to limit the initial position of the melt-disconnecting component. The limiting structure on the guiding block 92 can be an arc-separating ring arranged around the outer periphery of the guiding block. The connection between the arc-separating ring and the guiding block 92 is set as a breakage-weak part with reduced mechanical strength. While replacing the function of the limiting bumps 93 with the arc-separating ring, when the guiding block displaces, the arc after the melt is disconnected can be squeezed at the gap between the guiding block and the arc-separating ring to extinguish the arc.

[0050] The space between the displacement channel of the fuse cover 4 and the displacement channel of the guiding member 5 is closed by the melt-disconnecting component, and a sealed arc-extinguishing chamber is formed between the fuse cover, the guiding member, the melt-disconnecting component and the inner wall of the second housing, so as to prevent the arc-extinguishing medium filled between the fuse cover 4 and the guiding member 5 from entering the displacement channel. An arc-extinguishing medium is filled in the arc-extinguishing chamber, and the arc-extinguishing medium can be a gas arc-extinguishing medium, a solid arc-extinguishing medium or a colloidal arc-extinguishing medium.

[0051] During assembly, the above-mentioned various components are assembled according to Figure 1 the structure and in the assembly sequence. When the fuse is excited to work, the excitation source acts according to the received trigger signal, releases explosive gas as the driving force, and drives the piston to displace. After the piston disconnects the conductive part from the part to be disconnected of the conductive part, that is, the breakage-weak part, the piston continues to displace, and the cutter head part of the piston enters the displacement channel of the fuse cover, driving the melt-disconnecting component to displace. When the melt-disconnecting component is stressed for the first time, under the driving force of the piston, the limiting bumps on the guiding member break away from the guiding member, causing the guiding member to lose its limit. The piston pushes the melt-disconnecting component to displace, and the melt clamped on the melt-disconnecting component is disconnected. After the melt is disconnected, the backing plate absorbs and buffers the kinetic energy generated by the displacement of the melt-disconnecting component, reduces the impact force received at the closed end of the second housing, and provides a certain protection for the second housing.

Claims

1. An excitation fuse structure, characterized in that: It includes a first shell, a conductor assembly, a second shell, an excitation source, a piston, a melt disconnection assembly and a melt; the first shell, the conductor assembly and the second shell are spliced, the conductor assembly is located between the first shell and the second shell, the excitation source and the piston are located in the first shell, and the piston is arranged corresponding to the conductor of the conductor assembly; The second shell is an integrally formed structure with one end open and the other end closed, and the open end of the second shell is arranged toward the conductor assembly; a fuse structure is integrated in the second shell, the fuse is arranged in the fuse structure and is conductively connected in parallel with the conductor in the conductor assembly, and the fuse disconnection assembly is arranged in the fuse structure; When the excitation source is activated to release the driving force, the piston is driven to move, and after the piston disconnects the conductor of the conductor assembly, the melt disconnection assembly is pushed to disconnect the melt.

2. The excitation fuse structure according to claim 1, characterized in that: The fuse structure comprises a spliced ​​fuse cover and a guide member, wherein the fuse cover is arranged at the open end of the second shell, and the guide member is located at the bottom of the second shell; the fuse cover and the guide member are respectively provided with displacement channels penetrating the fuse structure on the piston displacement path, the melt passes through the displacement channels, the fuse disconnection assembly is arranged in the displacement channels, and the fuse cover and the guide member are used to define the initial position of the fuse disconnection assembly; A sealed arc-extinguishing chamber is formed between the fuse disconnection assembly, the second housing, the fuse cover and the guide member, and the arc-extinguishing chamber is filled with an arc-extinguishing medium.

3. The excitation fuse structure according to claim 2, characterized in that: The fuse cover and the guide piece are respectively integrally formed structures.

4. The excitation fuse structure according to claim 2, characterized in that: The fuse cover and the guide member respectively include platforms, and bosses protruding from the end surfaces are respectively arranged at corresponding positions of the end surfaces of the fuse cover and the guide member opposite to the platforms and on the displacement path of the piston, and the bosses are abutted; the displacement channel is located on the bosses of the fuse cover and the guide member.

5. The excitation fuse structure according to claim 4, characterized in that: The boss shape of the fuse cover is a variable cross-section structure whose cross-section gradually shrinks toward the guide member; support columns are respectively provided on the opposite end surfaces of the bosses on the fuse cover and the guide member and on the opposite sides of the displacement channel, extending toward each other, and the support columns of the fuse cover and the support columns of the guide member are abutted.

6. The excitation fuse structure according to claim 5, characterized in that: The melt disconnection assembly comprises a butt-jointed push block and a guide block, wherein the butt joint surfaces of the push block and the guide block are connected via a concave-convex structure or a hole-pin structure; the melt is clamped between the butt joint surfaces of the push block and the guide block.

7. The excitation fuse structure according to claim 6, characterized in that: A limiting structure is provided between the two ends of the guide block in the displacement direction; the limiting structure is a limiting protrusion provided on the opposite sides of the guide block, or is a circle of arc-isolating ring provided around the outer circumference of the guide block; a disconnection weak point is provided at the connection between the limiting structure and the guide block; the limiting structure is bridged between the fuse cover and the boss on the guide member; in the displacement channel at the fuse cover, a limiting step is provided toward the guide member, the limiting step is pressed against one end of the push block toward the piston, and the initial position of the fuse disconnection assembly is limited by the limiting step and the limiting structure.

8. The excitation fuse structure according to claim 4, characterized in that: Limiting steps are respectively arranged on the open end of the second shell and the inner wall near the closed end, and a plurality of protruding structures are arranged at intervals in the bottom of the closed end; the fuse cover is arranged at the limiting step at the open end to close the open end of the second shell, and the guide member is arranged on the limiting step near the closed end and is in sealing contact with the inner wall of the second shell near the closed end, so that the sealed arc extinguishing chamber is formed between the fuse disconnection assembly, the second shell, the fuse cover and the guide member.

9. The excitation fuse structure according to claim 8, characterized in that: A groove is provided at the outer end surface of the bottom of the guide member, and a plurality of positioning columns are arranged in the groove; a pad is provided between the bottom of the guide member and the bottom of the closed end of the second shell, the pad is located in the groove outside the guide member and is supported by the protruding structure, and the positioning columns pass through the pad to position it; the pad is suspended in the portion facing the displacement channel.

10. The excitation fuse structure according to claim 1, characterized in that: The conductor assembly includes an integrally formed conductive part and an insulating support part, wherein the support part is located between the contact surfaces of the conductor assembly and the first shell and the second shell respectively; the contact surface of the conductor assembly and the first shell is sealed and positioned by a sealing structure, and the contact surface of the conductor assembly and the second shell is positioned by a positioning structure.

11. The excitation fuse structure according to claim 10, characterized in that: A nested sealing ring with a protruding end face is arranged on the end face of the support member facing the first shell, and the nested sealing ring is nested in the end face in contact with the first shell to form the sealing structure; the nested sealing ring is arranged around the periphery of the area where the conductive member needs to be disconnected.

12. The excitation fuse structure according to claim 1, characterized in that: The piston is integrally formed and comprises a sleeve portion, a sealing portion and a cutter head portion which are integrally connected in sequence; the sleeve portion is located at the periphery of one end of the excitation source driving force release end to support the excitation source, the sealing portion extends obliquely outward toward the excitation source at one end portion of the excitation source to form an elastic lip and tongue structure, the sealing portion is in sealed contact with the first shell through an interference fit with the lip and tongue structure, and the cutter head portion is arranged corresponding to the conductive part of the conductor assembly.

13. The excitation fuse structure according to any one of claims 1 to 12, characterized in that: A reinforcing piece for enhancing the mechanical strength of the first shell is embedded in the inner wall of the first shell.

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