Fuse for power system protection in motion state and manufacturing process thereof

Abstract

The application relates to the technical field of fuses, in particular to a fuse suitable for power system protection under a motion state and a manufacturing process thereof, which comprises a ceramic shell, end covers, a wiring board, a limiting seat, a fuse body, a three-prism, a connecting rod and a reinforced arc-extinguishing assembly, two end covers are respectively arranged at two ends of the ceramic shell, the wiring board is arranged on the end covers in a penetrating mode, and the limiting seat is arranged on the wiring board on one side in the ceramic shell. The spiral fuse body with Greek frets is arranged on the outer side of the three-prism in a tensioning and winding mode, the connecting rod is filled with the resin column to solidify the fuse body structure, the reinforced arc-extinguishing assembly and the sealing film which are linked with the connecting rod are arranged on the inner wall of the ceramic shell, the problems that the fuse is mis-tripped due to vibration fatigue under the motion state, the structure is failed due to impact, the arc-extinguishing medium is displaced, and the sealing is failed due to dynamic pressure are solved, and the fuse has the effects of anti-vibration fatigue, anti-impact stable arc-extinguishing and dynamic sealing reliability.

Description

Technical Field

[0001] This invention relates to the field of fuse technology, specifically to fuses and their manufacturing processes suitable for power system protection in motion. Background Technology

[0002] As a widely used overload and short-circuit protection device in power systems, fuses automatically disconnect circuits by melting the fusible element under fault current, thereby protecting downstream equipment and lines. With the rapid development of rail transit, new energy vehicles, aerospace, and various mobile equipment, the application scenarios of power systems have gradually expanded from traditional fixed power distribution environments to dynamic application scenarios in motion.

[0003] In a power system in motion, the electrical performance exhibits significant dynamic characteristics due to the constant speed variation of the equipment. On the one hand, as the speed of movement accelerates, decelerates, and switches to constant speed, the load power fluctuates, causing the current and voltage in the system to undergo unsteady changes, rather than the relatively constant electrical parameters found in traditional fixed scenarios. On the other hand, the equipment in motion is also subjected to continuous changes in environmental stresses such as acceleration impacts, random vibrations, and temperature and air pressure. The combined effect of electrical impact loads and mechanical environmental stresses places far higher demands on the reliability of fuses than in traditional fixed applications. Existing fuse structures reveal several shortcomings under these conditions, specifically in the following aspects: Firstly, mechanical fatigue and false tripping caused by high-frequency vibration. In dynamic environments, power systems are constantly under random vibration. Traditional fuses have a relatively simple fuse element structure and lack stress redundancy design. Under the continuous action of cyclic alternating stress, the fuse element is prone to microcracks that gradually propagate, causing fatigue fracture before reaching the rated fusing current, resulting in false breaking and seriously affecting the continuity and reliability of power system operation. Secondly, there are structural failures and arc-extinguishing medium displacement problems under extreme impacts. Equipment in motion is often accompanied by transient impact loads. Such impacts can easily cause the ceramic body of the fuse tube to shatter or cause shearing at the terminal connection, damaging the overall structural integrity of the fuse. At the same time, strong impacts can also disturb the dense distribution of the arc-extinguishing filler (such as quartz sand) inside the fuse, creating local voids. This causes the arc path of the fuse element to lose effective constraint during the arcing stage and expand uncontrollably, leading to fuse tube rupture and posing a serious safety hazard.

[0004] Therefore, a fuse suitable for power system protection under dynamic conditions and its manufacturing process are proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a fuse suitable for power system protection in motion and its manufacturing process. By tensioning and winding a spiral fusible element with a Greek key pattern on the outside of a triangular prism, solidifying the fusible element structure by injecting a connecting rod with a resin column, and setting a reinforced arc-extinguishing component and a sealing membrane linked to the connecting rod on the inner wall of the ceramic shell, this invention solves the problems of accidental breakage due to vibration fatigue, structural failure due to impact, displacement of the arc-extinguishing medium, and sealing failure due to dynamic pressure in fuses in motion. It has the effects of vibration fatigue resistance, impact resistance, stable arc extinguishing, and reliable dynamic sealing.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A fuse suitable for power system protection in motion includes a ceramic housing, end caps, terminal blocks, limit seats, a fusible element, triangular prisms, connecting rods, and a reinforced arc-extinguishing assembly. Two end caps are respectively installed at both ends of the ceramic housing. The terminal block is installed through the end caps. The limit seats are fitted onto the side of the terminal block located inside the ceramic housing. Multiple triangular prisms are installed between the two terminal blocks. The fusible element is spirally distributed on the outside of the triangular prisms, and both ends of the fusible element are connected to the corresponding limit seats. A resin column is cast around the outer periphery of the fusible element. The connecting rod is connected to the outside of the fusible element and penetrates through the resin column. The reinforced arc-extinguishing assembly is installed on the inner wall of the ceramic housing, and the end of the connecting rod abuts against the side wall of the reinforced arc-extinguishing assembly.

[0007] Preferably, the wiring board includes an inner retaining plate, positioning holes, an outer connecting plate, and a through groove. The inner retaining plate is fitted onto the end cover, and multiple positioning holes are equally spaced on the inner retaining plate. The outer connecting plate is integrally connected to the inner retaining plate and penetrates through the end cover. The through groove is formed on the side wall of the outer connecting plate.

[0008] Preferably, the melt has slots at both ends, multiple narrow sections on the melt, through holes on the narrow sections, and Greek key patterns on the narrow sections.

[0009] Preferably, both ends of the triangular prism are fitted with insulating seats, and the insulating seats are adapted to the positioning holes. The sidewalls of the triangular prism are fitted with support columns, and the support columns extend into the resin column and abut against the inner side of the Greek meander pattern of the melt. The outer periphery of the triangular prism is machined into a friction surface.

[0010] Preferably, the enhanced arc extinguishing assembly includes a placement box, a box door, an extension rod, a bonding rod, and a sealing membrane. The placement box is fitted and installed on the inner circumference of the ceramic shell, and the placement box is filled with fire extinguishing filler. The box door is rotatably connected to the side wall of the placement box, and the side wall of the box door is abutted against the end of the connecting rod that is not connected to the melt. The ends of the extension rod are rotatably connected to the two box doors respectively. The sealing membrane is sealed and bonded to the circular hole in the side wall of the ceramic shell. The bonding rod is connected to the end of the extension rod, and the end of the bonding rod is bonded and connected to the inner side of the sealing membrane.

[0011] Preferably, the number of connecting rods is set to two, and the two connecting rods are located in the same vertical direction and are symmetrically arranged about the middle part of the melt.

[0012] Preferably, in the initial state, the Greek key pattern portion of the melt is under tension under the action of the support column, and the Greek key pattern portion is located between adjacent narrow portions.

[0013] Preferably, both the positioning hole and the insulating seat are bowl-shaped, and the length of the resin column is less than the length of the triangular prism.

[0014] A manufacturing process includes the following steps: S1. Machining and forming a ceramic shell, end cap, terminal block, limit seat, melt, triangular prism, connecting rod, reinforced arc extinguishing component and resin column; wherein the terminal block is machined with an inner clamping plate, positioning hole, outer connecting plate and through groove; the outer periphery of the triangular prism is machined with a friction surface; the two ends are fitted with insulating seats; the side wall is fitted with support columns; the melt has clamping grooves at both ends; multiple narrow sections are machined along the length direction; through holes and Greek fretwork are opened on the narrow sections; S2. Fit the inner clamping plate of the terminal block to the end cover, extend the outer plate through the end cover, and fit the limiting seat to the side of the terminal block inside the ceramic shell; make the insulating seats at both ends of the triangular prism match the positioning holes of the terminal block, and limit the installation of multiple triangular prisms between the two terminal blocks with the end cover already assembled. S3. The melt is spirally wound around the outside of the triangular prism and extended to the inside of the Greek key pattern with the help of the support column, so that the melt is in a tensile state. The slots at both ends of the melt are connected and fixed to the corresponding limit seats respectively. S4. Resin is poured into the outer periphery of the melt and cured to form a resin column with a length less than that of a triangular prism. During the pouring, two connecting rods are symmetrically placed on both sides of the same vertical direction in the middle part of the melt, so that the connecting rods are connected to the outside of the melt and penetrate the resin column. The placement box is fitted and installed on the inner periphery of the ceramic shell and filled with fire extinguishing filler. The box door is rotatably connected to the side wall of the placement box. The ends of the extension rods are rotatably connected to the two box doors respectively. The sealing film is sealed and fitted into the round hole on the side wall of the ceramic shell. The fitting rod is connected to the end of the extension rod and is fitted and connected to the inside of the sealing film, thus completing the pre-assembly of the reinforced arc extinguishing component in the ceramic shell. S5. Place the resin column into the ceramic shell, so that the end of the connecting rod not connected to the melt abuts against the side wall of the box door and the end of the connecting rod abuts against the side wall of the reinforced arc extinguishing component, forming a pre-tightened state before melting. Then, install the two end caps of the assembled wiring board at both ends of the ceramic shell, so that the limiting seat, triangular prism and melt assembly are fixed as a whole. Seal the connection between the end cap and the ceramic shell and the connection between the sealing film and the round hole.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the initial state, the Greek key pattern section is under tension under the action of the support column and is located between adjacent narrow sections. On the one hand, this structure increases the contact constraint between the melt and the skeleton through the cooperation of the spiral distribution and the outer peripheral friction surface of the triangular prism, suppressing the free swing of the melt under vibration. On the other hand, the Greek key pattern section forms an elastic stress redundancy range under the tension and pre-tightening state. When the equipment is in a random vibration environment, the alternating stress can be buffered and released through the elastic deformation of the Greek key pattern, avoiding stress concentration at a single point in the narrow section and premature initiation and expansion of microcracks. This effectively solves the technical problem that traditional melts lack stress redundancy, cause fatigue fracture under cyclic alternating stress, and cause false disconnection due to failure to reach the rated current, significantly improving the vibration fatigue reliability of the fuse under motion.

[0016] 2. A resin column is formed by pouring resin into the outer periphery of the melt, and a connecting rod passes through the resin column and connects to the outside of the melt. This solidifies the originally suspended and wound spiral melt into a one-piece structure, avoiding shearing misalignment between the melt and the end cap due to free oscillation under transient impact. At the same time, the placement box in the arc extinguishing assembly is filled with fire extinguishing filler and fitted to the inner periphery of the ceramic shell. Under normal conditions, the box door is in a pre-tight closed state with the connecting rod, preventing local voids in the internal arc extinguishing filler due to disturbance when the ceramic body is subjected to impact and vibration. When the melt melts due to fault current and the connecting rod loses support, the box door rotates and opens, releasing the fire extinguishing filler through the linkage of the extension rod and the fitting rod. This achieves on-demand and directional replenishment of the arc extinguishing medium, avoiding the problem of premature displacement and damage to the compactness of the arc extinguishing medium caused by transient impact, and ensuring that the arc path is effectively constrained during the arcing stage. This solves the technical problems of ceramic body breakage, terminal detachment, and tube explosion caused by uncontrolled arc path under extreme impact conditions in traditional fuses.

[0017] 3. A sealing membrane is sealed and bonded inside the circular hole on the side wall of the ceramic shell, and is bonded and connected to the inner side of the bonding rod in the reinforced arc extinguishing assembly. This forms a flexible sealing barrier under normal operating conditions of the fuse. Compared with the traditional completely rigid sealing structure, this sealing membrane can undergo adaptive micro-deformation when the internal and external pressure differences are generated during the movement of the equipment due to temperature fluctuations and air pressure changes (such as when a new energy vehicle is driving at high speed). This alleviates the repeated impact of the internal and external pressure differences on the sealing structure, reduces the risk of external water vapor entering the fuse through the pressure difference, and solves the technical problem of oxidation of the internal melt and deterioration of insulation performance caused by the breathing effect in the traditional completely sealed structure. This improves the long-term sealing reliability and service life of the fuse under continuous temperature and air pressure changes. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the end cap, melt, and triangular prism of the present invention; Figure 3 This is a schematic diagram of the triangular prism and resin column of the present invention; Figure 4 This is a schematic diagram of the terminal block of the present invention; Figure 5 This is a schematic diagram of the melt and connecting column of the present invention; Figure 6 For the present invention Figure 5 Enlarged schematic diagram of the structure at point A; Figure 7 This is a schematic diagram of the structure of the enhanced arc extinguishing component of the present invention.

[0019] In the diagram: 1. Ceramic shell; 2. End cap; 3. Terminal block; 31. Inner retaining plate; 32. Positioning hole; 33. Outer plate; 34. Through groove; 4. Limiting seat; 5. Melt; 51. Slot; 52. Narrow section; 53. Through hole; 54. Greek key pattern; 6. Triangular prism; 61. Insulating seat; 62. Support column; 63. Friction surface; 7. Connecting rod; 8. Reinforced arc extinguishing assembly; 81. Placement box; 82. Box door; 83. Extension rod; 84. Adhesive rod; 85. Sealing membrane; 9. Resin column. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figures 1 to 7 This invention provides a fuse suitable for power system protection under dynamic conditions and its manufacturing process. The technical solution is as follows: Reference Figure 1 , Figure 2 and Figure 3This fuse, suitable for power system protection during operation, includes a ceramic housing 1, end caps 2, a terminal block 3, a limiting seat 4, a fusible element 5, a triangular prism 6, a connecting rod 7, and a reinforced arc-extinguishing assembly 8. Two end caps 2 are respectively installed at both ends of the ceramic housing 1. The ceramic housing 1 is a hollow cylindrical structure made of high-strength, high-temperature resistant ceramic material, possessing excellent insulation performance and arc erosion resistance, capable of withstanding vibration, impact loads, and arc burning during operation. The two end caps 2 are respectively installed at both ends of the ceramic housing 1, threaded or snap-fitted to the ends of the ceramic housing 1, forming a relatively closed internal mounting cavity. This cavity provides insulation protection and structural limiting space for internal components such as the fusible element 5, triangular prism 6, and reinforced arc-extinguishing assembly 8. The terminal block 3 is installed through the end caps 2, with one end extending outside the end cap 2 as the electrical terminal for external wiring of the fuse, connecting to external conductors of the power system during operation; the other end is located inside the ceramic housing 1. The limiting seat 4 is fitted against the side of the terminal block 3 located inside the ceramic housing 1, serving as a fixed connection base for the end of the fusible element 5. Multiple triangular prisms 6 are installed between two terminal blocks 3 and are evenly arranged around the ceramic shell 1 to form a skeleton structure for winding the melt 5. The melt 5 is spirally distributed on the outside of the triangular prism 6. Both ends of the melt 5 are connected to the corresponding limiting seats 4, realizing a complete current conduction circuit from the terminal block 3 through the limiting seats 4 into the melt 5, and then through the other end of the limiting seats 4 and the terminal block 3 out. The limiting seats 4 are fitted and installed on the side of the terminal block 3 inside the ceramic shell 1. Multiple triangular prisms 6 are limited and installed between two terminal blocks 3. The melt 5 is spirally distributed on the outside of the triangular prism 6, and both ends of the melt 5 are connected to the corresponding limiting seats 4. Resin columns 9 are poured and molded on the outer periphery of the melt 5, solidifying and wrapping the spirally tensioned melt 5 into an integrated structure. The end of the connecting rod 7 away from the melt 5 abuts and fits against the side wall of the reinforced arc extinguishing component 8, forming a pre-tight assembly state before melting. The connecting rod 7 is connected to the outside of the melt 5 and passes through the resin column 9. The reinforced arc extinguishing component 8 is installed on the inner wall of the ceramic shell 1, and the end of the connecting rod 7 abuts against the side wall of the reinforced arc extinguishing component 8, forming a pre-tight assembly state before melting.

[0022] Reference Figure 4In one embodiment of the present invention, the terminal block 3 specifically includes an inner retaining plate 31, positioning holes 32, an outer connecting plate 33, and a through groove 34. The inner retaining plate 31 is fitted onto the end cover 2. Multiple positioning holes 32 are equally spaced on the inner retaining plate 31 to adapt to the insulating seats 61 at both ends of the triangular prism 6, thereby achieving circumferential positioning of the triangular prism 6 on the terminal block 3. The outer connecting plate 33 is integrally connected to the inner retaining plate 31 and penetrates the end cover 2. The through groove 34 is formed on the side wall of the outer connecting plate 33. The inner retaining plate 31 is fitted onto the end face of the end cover 2 located inside the ceramic shell 1. The outer connecting plate 33 is integrally connected to the inner retaining plate 31. The inner plate 31 extends beyond the end cover 2 and serves as an external wiring terminal. The side wall of the outer plate 33 has a through groove 34 for securing or routing external wires, facilitating a quick and reliable connection between the external wires of the power system and the fuse during operation. By adopting a structural design that integrates the inner plate 31 and the outer plate 33, the addition of conductive transition parts is avoided, simplifying the number of parts and conductive paths of the terminal block 3. Furthermore, the installation method of the inner plate 31 fitting against the inner end face of the end cover 2, combined with the limiting position of the outer plate 33 penetrating the end cover 2, enables the terminal block 3 to have strong resistance to pull-out and movement under vibration conditions.

[0023] Reference Figure 5 and Figure 6 In one embodiment of the present invention, specifically, slots 51 are provided at both ends of the fusible element 5, and multiple narrow sections 52 are provided on the fusible element 5. Through holes 53 are provided on the narrow sections 52, and Greek key patterns 54 are also provided on the narrow sections 52. The narrow sections 52 are sections with relatively small cross-sectional areas on the fusible element 5. Under the rated current, the current density in the narrow sections 52 is relatively large and the heat generation is relatively concentrated. The opening of the through holes 53 further reduces the local cross-sectional area of ​​the narrow sections 52, which is used to accurately control the rated fusing current threshold of the narrow sections 52, so that the breaking characteristics of the fuse meet the selection requirements of different application scenarios. When an overload or short-circuit fault occurs in the power system and the current flowing through the fusible element 5 exceeds the rated value, the narrow sections 52 generate local high temperature first due to the concentrated current density and melt first, cutting off the fault current path. This is the main fusing section of the fuse that realizes current protection.

[0024] The Greek key pattern 54 is located on the narrow section 52, and has a zigzag shape. After the molten body 5 is installed on the outside of the triangular prism 6, the Greek key pattern 54 abuts against the inner side of the adjacent support column 62. The Greek key pattern 54 is not a main melt-breaking section, but rather a stress buffer part in the overall structure of the molten body 5: in the initial assembly state, the Greek key pattern 54 is under tension due to the extended abutment of the support column 62, and the Greek key pattern 54 is located between adjacent narrow sections 52. When the equipment is in motion and accompanied by high-frequency vibration, the alternating stress caused by the vibration is transmitted through the melt 5. It is first absorbed and buffered by the bending structure of the Greek key 54 part in the form of elastic tension deformation, thereby avoiding stress concentration transmission and superposition to the narrow part 52 position. This prevents the narrow part 52 from developing microcracks due to vibration fatigue under normal operating current, or even prematurely melting and breaking. This effectively solves the technical problem of the traditional melt 5 being prone to fatigue fracture under cyclic alternating stress due to lack of stress redundancy, which leads to false breakage. After the narrow part 52 melts and breaks, the Greek key 54 part, which was originally tensioned and constrained by the support column 62, loses its tension balance due to the breakage of the continuous melt 5 and undergoes contraction and rebound, further accelerating the complete separation of the melt 5 at the melting point and shortening the continuous arcing time of the fault current.

[0025] Reference Figure 3 and Figure 5 In one embodiment of the present invention, specifically, insulating seats 61 are attached to both ends of the triangular prism 6, and the insulating seats 61 are adapted to the positioning holes 32. Supporting columns 62 are attached to the side walls of the triangular prism 6, and the supporting columns 62 extend into the resin column 9 and abut against the inner side of the Greek meander pattern 54 of the melt 5. The outer periphery of the triangular prism 6 is processed into a friction surface 63. After the melt 5 is wound and installed, the supporting columns 62 apply continuous supporting tension to the inner side of the Greek meander pattern 54, so that the Greek meander pattern 54 is always kept in a tensile state. The friction surface 63 can be processed by knurling, sandblasting and other processes to form a rough surface structure. The friction surface 63 increases the frictional contact force between the triangular prism 6 and the melt 5 and the outer periphery injected resin column 9, suppresses the radial movement or axial slippage of the melt 5 along the surface of the triangular prism 6 under vibration conditions, and further improves the overall stability of the spiral melt 5 skeleton structure under vibration and impact conditions.

[0026] Reference Figure 7As one embodiment of the present invention, specifically, the enhanced arc extinguishing assembly 8 includes a placement box 81, a box door 82, an extension rod 83, a bonding rod 84, and a sealing membrane 85. The placement box 81 is fitted and installed on the inner circumference of the ceramic shell 1, and the placement box 81 is filled with fire extinguishing filler. The box door 82 is rotatably connected to the side wall of the placement box 81, and the side wall of the box door 82 is abutted and fitted with the end of the connecting rod 7 that is not connected to the melt 5. The ends of the extension rod 83 are rotatably connected to the two boxes 82 respectively. The sealing membrane 85 is sealed and fitted into the round hole in the side wall of the ceramic shell 1. The bonding rod 84 is connected to the end of the extension rod 83, and the end of the bonding rod 84 is fitted and connected to the inner side of the sealing membrane 85. Under normal working conditions, the end of the connecting rod 7 that is not connected to the melt 5 is abutted and fitted with the side wall of the box door 82, forming a pre-tightening support for the box door 82, so that the box door 82 is kept closed, and the fire extinguishing filler in the placement box 81 is stably sealed in the placement box 81. Within 1, there will be no premature leakage or disturbance of the tightness due to equipment vibration or impact; when the narrow part 52 melts and the temperature of the melt 5 rises sharply, the resin around the part where the connecting rod 7 penetrates the resin column 9 will locally melt and soften due to the high temperature, and the constraint of the resin column 9 that was originally solidified and wrapped around the connecting rod 7 will be released; at the same time, the displacement tension generated by the melting and contraction of the melt 5 will act on the connecting rod 7 that is fixedly connected to it. After the resin constraint is released, the connecting rod 7 can be smoothly and passively pulled and moved away from the box door 82. After the connecting rod 7 moves away, the box door 82 loses the abutment and support constraint of the connecting rod 7, and the bottom of the box door 82 will immediately flip outward and open. The fire extinguishing filler placed in the box 81 will be quickly released into the area inside the ceramic shell 1 where the melt 5 melts and generates an electric arc through the opening formed by the outward flip of the bottom of the box door 82. The fire extinguishing filler wraps around and cools the electric arc channel, accelerates the extinguishing of the electric arc, and avoids the uncontrolled expansion of the electric arc path, which may cause the ceramic shell 1 to crack.

[0027] Reference Figure 5 As one embodiment of the present invention, specifically, the number of connecting rods 7 is set to two, and the two connecting rods 7 are located in the same vertical direction and are symmetrically arranged about the middle part of the melt 5.

[0028] Reference Figure 5 and Figure 6 As one embodiment of the present invention, specifically, in the initial state, the Greek key pattern 54 portion of the melt 5 is under tension under the action of the support column 62, and the Greek key pattern 54 portion is located between adjacent narrow portions 52. Throughout the entire service life, the Greek key pattern 54 portion always has the elastic redundancy ability to absorb vibration stress and will not lose its stress buffering function due to potting and curing.

[0029] Reference Figure 3 and Figure 4In one embodiment of the present invention, the positioning hole 32 and the insulating seat 61 are both set in a bowl shape. The length of the resin column 9 is less than the length of the triangular prism 6. The resin column 9 only wraps the main melting section of the spiral winding of the melt 5, while the connection parts of the two ends of the triangular prism 6 near the limiting seat 4 and the insulating seat 61 are not wrapped and covered by the resin column 9. This leaves room for movement between the two end slots 51 of the melt 5 and the limiting seat 4 without being constrained by resin curing, which facilitates the tensioning operation and snap-fit ​​fixation of the melt 5 during installation. At the same time, it avoids the overflow of the resin column 9 during pouring and contamination of the limiting seat 4, the terminal block 3 and other electrical connection parts.

[0030] A manufacturing process includes the following steps: S1. Machining and forming a ceramic shell 1, end cap 2, terminal block 3, limiting seat 4, melt 5, triangular prism 6, connecting rod 7, reinforced arc extinguishing component 8, and resin column 9; wherein the terminal block 3 is machined with an inner clamping plate 31, positioning hole 32, outer connecting plate 33, and through groove 34; the outer periphery of the triangular prism 6 is machined with a friction surface 63; the two ends are fitted with insulating seats 61; the side wall is fitted with support columns 62; the melt 5 has clamping grooves 51 at both ends; multiple narrow sections 52 are machined along the length direction; through holes 53 and Greek key patterns 54 are opened on the narrow sections 52; S2. The inner clamping plate 31 of the terminal block 3 is attached to the end cover 2, the outer plate 33 extends through the end cover 2, and the limiting seat 4 is attached to the side of the terminal block 3 located inside the ceramic shell 1; the insulating seats 61 at both ends of the triangular prism 6 are adapted to the positioning holes 32 of the terminal block 3, and multiple triangular prisms 6 are limited and installed between the two terminal blocks 3 with the end cover 2 already assembled. S3. The melt 5 is spirally wound around the outside of the triangular prism 6, and extended to the inside of the Greek key pattern 54 with the help of the support column 62, so that the melt 5 is in a tensile state. The slots 51 at both ends of the melt 5 are respectively connected and fixed to the corresponding limiting seats 4. S4. Resin is poured into the outer periphery of the melt 5 and cured to form a resin column 9 with a length less than that of the triangular prism 6. At the same time as pouring, two connecting rods 7 are symmetrically arranged on both sides of the same vertical direction in the middle part of the melt 5, so that the connecting rods 7 are connected to the outside of the melt 5 and penetrate the resin column 9. The placement box 81 is attached to the inner periphery of the ceramic shell 1 and filled with fire extinguishing filler. The box door 82 is rotatably connected to the side wall of the placement box 81. The ends of the extension rods 83 are rotatably connected to the two box doors 82 respectively. The sealing film 85 is sealed and attached to the round hole in the side wall of the ceramic shell 1. The attaching rod 84 is connected to the end of the extension rod 83 and attached to the inner side of the sealing film 85, thus completing the pre-assembly of the reinforced arc extinguishing component 8 in the ceramic shell 1. S5. Place the resin column 9 into the ceramic shell 1, so that the end of the connecting rod 7 not connected to the melt 5 abuts against the side wall of the box door 82 and the end of the connecting rod 7 abuts against the side wall of the reinforced arc extinguishing component 8, forming a pre-tightened state before melting. Then, install the two end caps 2 of the assembled wiring board 3 at both ends of the ceramic shell 1 respectively, so that the limiting seat 4, the triangular prism 6, and the melt 5 assembly are fixed as a whole. Seal the connection between the end cap 2 and the ceramic shell 1, and the connection between the sealing film 85 and the round hole.

[0031] Working principle: When an overload or short-circuit fault occurs in the power system and the current flowing through the fuse 5 exceeds the rated value, due to the small cross-sectional area of ​​the narrow section 52, the high current density, and the concentrated heat generation, the fuse 5 first generates local high temperature at the narrow section 52 and melts first, cutting off the fault current path. After the narrow section 52 melts, the Greek key pattern 54, which was originally tensioned by the support column 62, loses the constraint of the continuous fuse 5 and contracts and springs back, further accelerating the separation of the fuse 5 at the melted part and shortening the continuous arcing time of the fault current; As the melt 5 melts, the connecting rod 7, which is fixedly connected to the outside of the melt 5, is passively pulled away by the displacement caused by the contraction and fracture of the melt 5, and moves away from the box door 82. The end of the connecting rod 7 that is not connected to the melt 5 was originally in a pre-tight state against the side wall of the box door 82. At this time, due to the retraction of the connecting rod 7, it loses its resistance to the box door 82. The bottom of the box door 82 then flips outward and opens. The fire extinguishing filler pre-filled in the box 81 is released through the opening formed by the outward flip of the bottom of the box door 82 into the area inside the ceramic shell 1 where the melt 5 melts and generates an electric arc. The filler quickly wraps around and cools the electric arc channel, accelerates the extinguishing of the electric arc, and prevents the uncontrolled expansion of the electric arc path from causing the ceramic shell 1 to crack, thereby achieving a reliable and safe disconnection of the fault current. As the bottom of the box door 82 flips outward, the extension rod 83 connected to it causes the bonding rod 84 to shift, and the end of the bonding rod 84 then causes the sealing film 85 connected to it to bulge out.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fuse suitable for power system protection during operation, characterized in that: The assembly includes a ceramic shell (1), end caps (2), wiring plate (3), limiting seat (4), melt (5), triangular prism (6), connecting rod (7), and reinforced arc extinguishing component (8). The two end caps (2) are respectively installed at both ends of the ceramic shell (1). The wiring plate (3) is installed through the end caps (2). The limiting seat (4) is fitted to the wiring plate (3) on the side inside the ceramic shell (1). Multiple triangular prisms (6) are limited and installed between the two wiring plates (3). The melt (5) is spirally distributed on the outside of the triangular prisms (6), and both ends of the melt (5) are respectively connected to the corresponding limiting seat (4). The melt (5) is filled with resin columns (9) around its outer periphery. The connecting rod (7) is connected to the outside of the melt (5) and passes through the resin column (9). The reinforced arc extinguishing component (8) is installed on the inner wall of the ceramic shell (1), and the end of the connecting rod (7) abuts against the side wall of the reinforced arc extinguishing component (8). The melt (5) has slots (51) at both ends, and multiple narrow sections (52) are provided on the melt (5). The narrow sections (52) have through holes (53) and Greek fretwork (54) is also provided on the narrow sections (52).

2. The fuse for power system protection under dynamic conditions according to claim 1, characterized in that: The wiring board (3) includes an inner clamping plate (31), positioning holes (32), an outer connecting plate (33), and a through groove (34). The inner clamping plate (31) is fitted onto the end cover (2), and multiple positioning holes (32) are equally spaced on the inner clamping plate (31). The outer connecting plate (33) is integrally connected to the inner clamping plate (31) and penetrates the end cover (2). The through groove (34) is opened on the side wall of the outer connecting plate (33).

3. The fuse for power system protection under dynamic conditions according to claim 2, characterized in that: Both ends of the triangular prism (6) are fitted with insulating seats (61), and the insulating seats (61) are adapted to the positioning holes (32). The sidewalls of the triangular prism (6) are fitted with support columns (62), and the support columns (62) extend into the resin column (9) and abut against the inner side of the Greek meander (54) part of the melt (5). The outer periphery of the triangular prism (6) is machined into a friction surface (63).

4. The fuse for power system protection under dynamic conditions according to claim 1, characterized in that: The enhanced arc extinguishing assembly (8) includes a placement box (81), a box door (82), an extension rod (83), a bonding rod (84), and a sealing film (85). The placement box (81) is fitted and installed on the inner circumference of the ceramic shell (1), and the placement box (81) is filled with fire extinguishing filler. The box door (82) is rotatably connected to the side wall of the placement box (81), and the side wall of the box door (82) and the end of the connecting rod (7) that is not connected to the melt (5) are abutted and fitted. The ends of the extension rod (83) are rotatably connected to the two boxes (82) respectively. The sealing film (85) is sealed and fitted in the round hole of the side wall of the ceramic shell (1). The bonding rod (84) is connected to the end of the extension rod (83), and the end of the bonding rod (84) is fitted and connected to the inner side of the sealing film (85).

5. The fuse for power system protection under dynamic conditions according to claim 1, characterized in that: The number of connecting rods (7) is set to two, and the two connecting rods (7) are located in the same vertical direction and are symmetrically arranged about the middle part of the melt (5).

6. The fuse for power system protection under dynamic conditions according to claim 1, characterized in that: In the initial state, the Greek key pattern (54) of the melt (5) is under tension under the action of the support column (62), and the Greek key pattern (54) is located between adjacent narrow sections (52).

7. The fuse for power system protection under dynamic conditions according to claim 3, characterized in that: The positioning hole (32) and the insulating seat (61) are both set in a bowl shape, and the length of the resin column (9) is less than the length of the triangular prism (6).

8. A manufacturing process applicable to the fuse according to any one of claims 1 to 7, characterized in that: Includes the following steps: S1. Process and form a ceramic shell (1), end cap (2), terminal block (3), limit seat (4), melt (5), triangular prism (6), connecting rod (7), reinforced arc extinguishing component (8) and resin column (9); wherein the terminal block (3) is processed with an inner card plate (31), positioning hole (32), outer plate (33) and through groove (34), the triangular prism (6) is processed with a friction surface (63) on the outer periphery, the two ends are fitted with an insulating seat (61), the side wall is fitted with a support column (62), the melt (5) has card slots (51) at both ends, and multiple narrow parts (52) are processed along the length direction, and through holes (53) and Greek key patterns (54) are opened on the narrow parts (52); S2. The inner clamping plate (31) of the terminal block (3) is attached to the end cover (2), the outer plate (33) extends through the end cover (2), and the limiting seat (4) is attached to the side of the terminal block (3) inside the ceramic shell (1); the insulating seats (61) at both ends of the triangular prism (6) are matched with the positioning holes (32) of the terminal block (3), and multiple triangular prisms (6) are limited and installed between the two terminal blocks (3) with the end cover (2) already assembled; S3. The melt (5) is spirally wound around the outside of the triangular prism (6), and extended to the inside of the Greek meander (54) part by means of the support column (62), so that the melt (5) is in a tensile state, and the slots (51) at both ends of the melt (5) are connected and fixed to the corresponding limiting seats (4); S4. Resin is poured into the outer periphery of the melt (5) and cured to form a resin column (9) with a length less than that of the triangular prism (6). At the same time as pouring, two connecting rods (7) are symmetrically placed on both sides of the same vertical direction in the middle part of the melt (5), so that the connecting rods (7) are connected to the outside of the melt (5) and penetrate the resin column (9). The placement box (81) is fitted and installed on the inner periphery of the ceramic shell (1) and filled with fire extinguishing filler. The box door (82) is rotatably connected to the side wall of the placement box (81). The ends of the extension rod (83) are rotatably connected to the two box doors (82) respectively. The sealing film (85) is sealed and fitted into the round hole on the side wall of the ceramic shell (1). The fitting rod (84) is connected to the end of the extension rod (83) and fitted and connected to the inside of the sealing film (85). The pre-assembly of the reinforced arc extinguishing component (8) in the ceramic shell (1) is completed. S5. Place the resin column (9) into the ceramic shell (1), so that the end of the connecting rod (7) not connected to the melt (5) abuts against the side wall of the box door (82) and the end of the connecting rod (7) abuts against the side wall of the reinforced arc extinguishing component (8), forming a pre-tightened state before melting. Then, install the two end caps (2) of the assembled wiring board (3) at both ends of the ceramic shell (1) respectively, so that the limiting seat (4), the triangular prism (6), and the melt (5) assembly are fixed as a whole. Seal the connection between the end cap (2) and the ceramic shell (1) and the connection between the sealing film (85) and the round hole.

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