A high voltage fast acting fuse

Abstract

This application discloses a high-voltage fast-acting fuse, belonging to the field of circuit protection components. The high-voltage fast-acting fuse includes an insulating ceramic tube, a first conductive cover plate and a second conductive cover plate respectively fixed to both ends of the insulating ceramic tube, a fusible element disposed inside the insulating ceramic tube and energized by the first and second conductive cover plates, and an elastic isolation mechanism disposed inside the insulating ceramic tube near both ends and energized by the two ends of the fusible element and the first and second conductive cover plates. This mechanism applies an axial force to the first and second conductive cover plates after the fusible element melts, increasing the isolation distance between the melted ends of the fusible element. This high-voltage fast-acting fuse, by incorporating the elastic isolation mechanism, actively releases elastic potential energy at the moment of melt fracture, applying an axial force to both ends to forcibly pull the melted ends apart, forming a reliable physical isolation gap, significantly improving the reliability of the breakage.

Description

Technical Field

[0001] This application relates to the field of circuit protection components, specifically a high-voltage fast-acting fuse. Background Technology

[0002] In high-voltage DC systems such as new energy, rail transit, and industrial frequency conversion, circuit protection components face extremely stringent challenges. Existing high-voltage fast-acting fuses primarily rely on silica sand to extinguish the arc. However, in DC circuits, due to the lack of a natural zero-crossing point for the current, high-voltage arcs are difficult to suppress effectively in a short time, easily leading to incomplete arc extinguishing or even arc reignition, resulting in equipment damage. Furthermore, after the fusible element melts, the limited gap between the fuse contacts in traditional fuses makes it easy for metal vapor to re-break down the gap under high voltage, hindering reliable physical isolation. To meet high-voltage requirements, existing technologies often require multiple fuses to be used in series, which not only results in a bulky structure and large space occupation but also increases contact resistance and potential failure points. Therefore, how to achieve rapid arc extinguishing while ensuring reliable isolation of the contacts is a pressing technical problem to be solved in this field.

[0003] Therefore, this application provides a high-voltage fast-acting fuse to solve the above-mentioned problems. Summary of the Invention

[0004] This application provides a high-voltage fast-acting fuse, which aims to solve the problems mentioned in the background art, such as the difficulty in extinguishing the arc and the incomplete isolation of the break point in existing fuses under high voltage conditions.

[0005] To achieve the above objectives, this application provides the following technical solution: a high-voltage fast-acting fuse, comprising an insulating ceramic tube, a first conductive cover plate and a second conductive cover plate respectively fixed to both ends of the insulating ceramic tube, a fusible element disposed inside the insulating ceramic tube and electrically connected to the first conductive cover plate and the second conductive cover plate, and further comprising: An insulating support frame is provided and snapped onto the inner wall of the insulating ceramic tube along the axial extension direction of the insulating ceramic tube, and the molten material is disposed on the insulating support frame; A powdered filling medium that is filled inside the insulating ceramic tube to encapsulate the melt and is used to extinguish electric arcs; An elastic isolation mechanism is disposed inside the insulating ceramic tube near both ends and electrically connected to both ends of the molten material, as well as the first and second conductive cover plates. It is used to apply an axial force to the first and second conductive cover plates after the molten material melts and breaks, thereby increasing the isolation distance between the melted ends of the molten material.

[0006] As a preferred embodiment of the present invention, the melt is a strip of silver or silver-copper alloy material, and the melt has a plurality of narrow segments arranged in a linear array. The narrow segments are localized contraction regions formed on the melt by stamping or etching processes.

[0007] As a preferred technical solution of the present invention, the material of the insulating support frame is selected from one or more combinations of melamine-formaldehyde resin, polytetrafluoroethylene, polyamide or polyoxymethylene. When the insulating support frame is subjected to high temperature burning by electric arc, its surface material undergoes thermal decomposition or vaporization, producing arc-extinguishing gases such as hydrogen, nitrogen or carbon dioxide, forming a gas blowing arc extinguishing effect inside the insulating ceramic tube.

[0008] As a preferred embodiment of the present invention, the insulating support frame includes two mounting plates that are fully adapted to the inner wall of the insulating ceramic tube. The mounting plates are snapped onto the inner wall of the insulating ceramic tube. A support frame is fixedly installed between the two mounting plates. A plurality of staggered guide columns are fixedly installed on the support frame. The melt is continuously wound around the outer wall of the guide columns in an S-shape.

[0009] As a preferred embodiment of the present invention, the support frame is provided with a plurality of holes arranged in a linear array, and the powdered filling medium is high-purity quartz sand, which is densely filled in the insulating ceramic tube at the position between the two mounting plates.

[0010] As a preferred embodiment of the present invention, the elastic isolation mechanism includes a mounting hole that penetrates the center of the mounting plate. A conductive post is movably mounted in the mounting hole along the axial extension direction of the insulating ceramic tube. A stop block is fixedly mounted on one end of the conductive post facing the first conductive cover plate and the second conductive cover plate. A spring is sleeved on the outer wall of the conductive post between the stop block and the outer wall of the mounting plate. The two ends of the conductive post are electrically connected to the first conductive cover plate, the second conductive cover plate, and the end of the molten material, respectively.

[0011] As a preferred embodiment of the present invention, a first connecting ring and a second connecting ring are fixedly installed at both ends of the conductive post, and the second connecting ring is fixedly connected to the melt by bolts.

[0012] As a preferred embodiment of the present invention, the first wiring ring is connected to the first conductive cover plate or the second conductive cover plate by a flexible connection, which is achieved by a wire. One end of the wire is welded to the first conductive cover plate and the second conductive cover plate, and the other end is fixedly connected to the first wiring ring by a bolt.

[0013] Compared with the prior art, the present invention provides a high-voltage fast-acting fuse, which has the following advantages: 1. This high-voltage fast-acting fuse, by setting an elastic isolation mechanism, actively releases elastic potential energy at the moment the fusible element melts, applies axial force to both ends, and forcibly pulls the fused break apart to form a reliable physical isolation gap. This mechanical action fundamentally solves the problem of high-voltage DC arc reignition caused by traditional fuses relying solely on passive arc extinguishing with quartz sand, and significantly improves the reliability of the break.

[0014] 2. This high-voltage fast-acting fuse uses an insulating support frame made of gas-generating material and a high-purity quartz sand powder filling medium to form a synergistic arc-extinguishing mechanism. The quartz sand provides cooling and adsorption, while the insulating support frame generates high-pressure arc-extinguishing gas when burned by an electric arc, forming a gas blowing effect in the sealed ceramic tube. The two complement each other and significantly enhance the suppression effect on high-voltage DC arcs, making it suitable for higher voltage levels.

[0015] 3. This high-voltage fast-acting fuse has an S-shaped fuse element wound around the staggered guide posts of the insulating support frame. This significantly increases the effective path length of the fuse element within a limited axial space, thereby improving the overall withstand voltage. At the same time, the guide posts ensure uniform electrical clearance between fuse segments, preventing mutual discharge. The structure is compact and saves installation space. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a high-voltage fast-acting fuse. Figure 2 This is a schematic diagram of the internal structure of a high-voltage fast-acting fuse. Figure 3 A schematic diagram of the conductive column structure of a high-voltage fast-acting fuse; Figure 4 A schematic diagram of the conductive column structure of a high-voltage fast-acting fuse; Figure 5 This is a schematic cross-sectional view of a high-voltage fast-acting fuse. Figure 6 This is a schematic diagram of the fusible element structure of a high-voltage fast-acting fuse.

[0017] In the picture: 1. Insulating ceramic tube; 2. First conductive cover plate; 3. Second conductive cover plate; 4. Molten material; 41. Narrow section; 5. Insulating support frame; 51. Mounting plate; 52. Support frame; 53. Guide post; 54. Leakage hole; 6. Powdered filling medium; 7. Elastic isolation mechanism; 71. Mounting hole; 72. Conductive post; 73. Abutment; 74. Spring; 75. First connecting ring; 76. Second connecting ring; 77. Wire. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Example 1 This embodiment provides a high-voltage fast-acting fuse, such as Figures 1-6 As shown, the high-voltage fast-acting fuse includes an insulating ceramic tube 1, a first conductive cover plate 2 and a second conductive cover plate 3 respectively fixed to both ends of the insulating ceramic tube 1, and a fusible element 4 disposed inside the insulating ceramic tube 1 and electrically connected to the first conductive cover plate 2 and the second conductive cover plate 3, and further includes: An insulating support frame 5 is provided along the axial extension direction of the insulating ceramic tube 1 and is snapped onto the inner wall of the insulating ceramic tube 1, and the molten material 4 is provided on the insulating support frame 5. A powdered filling medium 6, which is filled inside an insulating ceramic tube 1 and encapsulates the melt 4, is used to extinguish electric arcs. The elastic isolation mechanism 7 is disposed inside the insulating ceramic tube 1 near both ends and is electrically connected to both ends of the melt 4, as well as the first conductive cover plate 2 and the second conductive cover plate 3. It is used to apply an axial force to the first conductive cover plate 2 and the second conductive cover plate 3 after the melt 4 melts and breaks, thereby increasing the isolation distance between the melted ends of the melt 4.

[0020] During normal operation, the current flows through the first conductive cover plate 2, the elastic isolation mechanism 7, the fusible element 4, the elastic isolation mechanism 7 at the other end, and the second conductive cover plate 3 to form a circuit. The fusible element 4 remains under tension, constraining the elastic isolation mechanism 7 in the energy storage position. When a short circuit occurs, the fusible element 4 melts rapidly, its tension disappears, and the elastic isolation mechanism 7 releases the stored elastic potential energy, applying a force along the axial direction to both ends, forcibly pulling the melted joint apart to form a physical isolation gap. At the same time, the powdered filling medium 6 cools and absorbs the electric arc, and the insulating support frame 5 provides support for the fusible element 4 and maintains its stable position within the insulating ceramic tube 1. By setting the elastic isolation mechanism 7, active mechanical isolation after melting is achieved, fundamentally solving the problem of reignition caused by the passive arc extinguishing of traditional fuses that rely solely on the arc extinguishing medium. The insulating support frame 5 ensures that the position of the fusible element 4 is fixed, avoiding displacement caused by transportation or impact. The powdered filling medium 6 and the elastic isolation mechanism 7 work together to form a dual protection of "electrical extinguishing + physical isolation", significantly improving the breaking reliability under high voltage DC environment.

[0021] Specifically, the melt 4 is a strip of silver or silver-copper alloy material, and several narrow segments 41 are formed on the melt 4 in a linear array. The narrow segments 41 are local shrinkage areas formed on the melt 4 by stamping or etching processes.

[0022] In use, the cross-sectional area of ​​the narrow segment 41 is smaller than that of the melt body 4, resulting in higher resistance and current density. When a fault current passes through, the narrow segment 41 heats up preferentially and reaches its melting point, achieving point-to-point melting. Multiple narrow segments 41 are connected in series along the length of the melt body 4, dividing the long arc into multiple short arcs during melting. The strip-shaped silver or silver-copper alloy material has good conductivity and ductility, facilitating processing and carrying rated current. The design of the narrow segment 41 ensures precise and controllable melting point, avoiding performance differences caused by uncertain melting position. The multi-segment series structure utilizes the near-cathode effect to increase the arc extinguishing voltage and enhance the high-voltage arc extinguishing capability. Stamping or etching processes allow for mass production with good consistency and controllable cost.

[0023] More specifically, the insulating support frame 5 is made of one or more combinations of melamine-formaldehyde resin, polytetrafluoroethylene, polyamide or polyoxymethylene. When the insulating support frame 5 is subjected to high-temperature burning by an electric arc, its surface material undergoes thermal decomposition or vaporization, producing arc-extinguishing gases such as hydrogen, nitrogen or carbon dioxide, which form an arc-extinguishing effect in the insulating ceramic tube 1.

[0024] When in use, when the melt 4 melts and generates an electric arc, the high temperature of the arc instantly burns the surface of the insulating support frame 5, causing the material to decompose rapidly and generate high-pressure gas. This gas forms an airflow in the sealed insulating ceramic tube 1, which compresses, stretches and cools the arc. The gas-generating material and the quartz sand form a dual arc-extinguishing mechanism. The quartz sand provides cooling and adsorption, while the gas-generating gas provides a blowing effect. The two complement each other and significantly improve the ability to suppress high-voltage DC arcs. Different materials can be selected and combined to adapt to different voltage levels and breaking requirements. The blowing effect can quickly dissipate metal vapor, reduce the dielectric recovery strength and recovery time, and prevent the arc from reigniting.

[0025] Furthermore, the insulating support frame 5 includes two mounting plates 51 that are fully adapted to the inner wall of the insulating ceramic tube 1. The mounting plates 51 are snapped onto the inner wall of the insulating ceramic tube 1. A support frame 52 is fixedly installed between the two mounting plates 51. Several staggered guide posts 53 are fixedly installed on the support frame 52. The melt 4 is continuously wound around the outer wall of the guide posts 53 in an S-shape.

[0026] In use, the melt 4 is wound in an S-shaped path around the staggered guide posts 53. The mounting plate 51 fixes the entire skeleton assembly inside the insulating ceramic tube 1. The staggered layout between the guide posts 53 ensures that each segment of the melt 4 maintains a uniform electrical clearance. The S-shaped winding structure significantly increases the effective length of the melt 4 within a limited axial space, thereby improving the overall withstand voltage capability and making it suitable for higher voltage levels. The staggered distribution of the guide posts 53 ensures that the insulation distance between the segments of the melt 4 is uniform, avoiding mutual discharge. The snap-fit ​​mounting plate 51 facilitates assembly and improves production efficiency. The melt 4 is wound around the guide posts 53, which disperses the force and provides good resistance to mechanical impact.

[0027] Furthermore, the support frame 52 has several holes 54 arranged in a linear array. The powdered filling medium 6 is high-purity quartz sand, which is densely filled in the insulating ceramic tube 1 between the two mounting plates 51.

[0028] During use, when filling with quartz sand powder filling medium 6, the medium flows evenly into the interior of the support frame 52 and into the gaps of the melt 4 through the drain holes 54 on the support frame 52. After filling, a dense arc-extinguishing layer without voids is formed. The design of the drain holes 54 ensures that the quartz sand is filled evenly and densely, avoiding the decrease in local arc-extinguishing ability caused by dead corners in the filling. High-purity quartz sand has good thermal conductivity and insulation properties, which can quickly absorb arc energy and condense metal vapor. The dense filling enhances the restraint effect on the arc and improves the reliability of the break.

[0029] Example 2 Unlike Embodiment 1, in order to further optimize the specific implementation of the elastic isolation mechanism 7 and ensure that the break can be reliably pulled open and a stable electrical connection can be maintained after the melt 4 melts, this embodiment has a detailed design for the elastic isolation mechanism 7.

[0030] The elastic isolation mechanism 7 includes a mounting hole 71 that penetrates the center of the mounting plate 51. A conductive post 72 is movably installed in the mounting hole 71 along the axial extension direction of the insulating ceramic tube 1. A stop block 73 is fixedly installed on one end of the conductive post 72 facing the first conductive cover plate 2 and the second conductive cover plate 3. A spring 74 is sleeved on the outer wall of the conductive post 72 between the stop block 73 and the outer wall of the mounting plate 51. The two ends of the conductive post 72 are electrically connected to the first conductive cover plate 2, the second conductive cover plate 3, and the end of the melt 4, respectively.

[0031] During normal operation, the molten metal 4 is under tension and is stretched inward by the conductive post 72, causing the spring 74 to compress and store energy. After the molten metal 4 melts and breaks, the tension disappears, the spring 74 releases energy, and pushes the stop block 73 to move the conductive post 72 outward, thereby pulling the fracture surface apart to both ends. The elastic energy storage element is integrated in the center of the mounting plate 51, which is compact and does not occupy extra space. The conductive post 72 slides in the mounting hole 71, and the movement guidance is precise, ensuring that the fracture surface is pulled apart evenly along the axial direction. The energy storage method of the spring 74 is reliable and responds quickly, triggering instantly at the moment of melting and breaking.

[0032] Specifically, a first connecting ring 75 and a second connecting ring 76 are fixedly installed at both ends of the conductive post 72, and the second connecting ring 76 is fixedly connected to the melt 4 by bolts.

[0033] In use, the first connecting ring 75 is used to connect to the external circuit, and the second connecting ring 76 is used to connect to the end of the molten element 4. The electrical and mechanical connection is achieved by tightening with bolts. The connection method of connecting rings and bolts not only ensures good conductivity, but also facilitates assembly and later maintenance. The detachable connection makes it more convenient to replace the molten element 4 or repair the product. The connection is reliable and can withstand large currents and mechanical shocks.

[0034] More specifically, the first connecting ring 75 is connected to the first conductive cover plate 2 or the second conductive cover plate 3 by a flexible connection, which is achieved by a wire 77. One end of the wire 77 is welded to the first conductive cover plate 2 and the second conductive cover plate 3, and the other end is fixedly connected to the first connecting ring 75 by a bolt.

[0035] In use, a flexible wire 77 is used to connect the first terminal ring 75 to the conductive cover plate, so that when the conductive post 72 moves outward under the action of the spring 74, the flexible wire 77 can deform accordingly without affecting the degree of freedom of movement. The flexible connection avoids the interference of the rigid connection on the action of the elastic mechanism, ensuring that the break can be pulled open smoothly. The wire 77 can absorb vibration and impact, avoiding fatigue fracture at the connection point due to stress concentration. The dual fixing method of welding and bolts improves the reliability of the connection.

[0036] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and concept of this application, should be included within the scope of protection of this application.

Claims

1. A high-voltage fast-acting fuse, comprising an insulating ceramic tube (1), a first conductive cover plate (2) and a second conductive cover plate (3) respectively fixed to both ends of the insulating ceramic tube (1), and a fusible element (4) disposed inside the insulating ceramic tube (1) and electrically connected to the first conductive cover plate (2) and the second conductive cover plate (3), characterized in that, Also includes: An insulating support frame (5) is provided along the axial extension direction of the insulating ceramic tube (1) and is snapped onto the inner wall of the insulating ceramic tube (1), and the melt (4) is provided on the insulating support frame (5); A powdered filling medium (6) that is filled inside the insulating ceramic tube (1) to encapsulate the melt (4) for extinguishing the electric arc. The elastic isolation mechanism (7) is located inside the insulating ceramic tube (1) near both ends and is electrically connected to both ends of the melt (4) and the first conductive cover plate (2) and the second conductive cover plate (3). It is used to apply an axial force to the first conductive cover plate (2) and the second conductive cover plate (3) after the melt (4) melts, thereby increasing the isolation distance between the melted ports of the melt (4).

2. The high-voltage fast-acting fuse according to claim 1, characterized in that: The melt (4) is a strip of silver or silver-copper alloy material. Several narrow segments (41) are arranged in a linear array on the melt (4). The narrow segments (41) are local shrinkage areas formed on the melt (4) by stamping or etching processes.

3. A high-voltage fast-acting fuse according to claim 2, characterized in that: The insulating support frame (5) is made of one or more of melamine formaldehyde resin, polytetrafluoroethylene, polyamide or polyoxymethylene. When the insulating support frame (5) is subjected to high-temperature burning by electric arc, its surface material undergoes thermal decomposition or vaporization, producing arc-extinguishing gases such as hydrogen, nitrogen or carbon dioxide, which form an arc-extinguishing effect in the insulating ceramic tube (1).

4. A high-voltage fast-acting fuse according to claim 3, characterized in that: The insulating support frame (5) includes two mounting plates (51) that are fully adapted to the inner wall of the insulating ceramic tube (1). The mounting plates (51) are snapped onto the inner wall of the insulating ceramic tube (1). A support frame (52) is fixedly installed between the two mounting plates (51). Several staggered guide columns (53) are fixedly installed on the support frame (52). The melt (4) is continuously wound around the outer wall of the guide columns (53) in an S-shape.

5. A high-voltage fast-acting fuse according to claim 4, characterized in that: The support frame (52) has a number of holes (54) arranged in a linear array. The powdered filling medium (6) is high-purity quartz sand. The powdered filling medium (6) is densely filled in the insulating ceramic tube (1) at the position between the two mounting plates (51).

6. A high-voltage fast-acting fuse according to claim 4, characterized in that: The elastic isolation mechanism (7) includes a mounting hole (71) that penetrates the center of the mounting plate (51). A conductive post (72) is movably installed in the mounting hole (71) along the axial extension direction of the insulating ceramic tube (1). A stop block (73) is fixedly installed on one end of the conductive post (72) facing the first conductive cover plate (2) and the second conductive cover plate (3). A spring (74) is sleeved on the outer wall of the conductive post (72) between the stop block (73) and the outer wall of the mounting plate (51). The two ends of the conductive post (72) are electrically connected to the first conductive cover plate (2), the second conductive cover plate (3), and the end of the melt (4), respectively.

7. A high-voltage fast-acting fuse according to claim 6, characterized in that: The conductive post (72) has a first connecting ring (75) and a second connecting ring (76) fixedly installed at both ends, and the second connecting ring (76) is fixedly connected to the melt (4) by bolts.

8. A high-voltage fast-acting fuse according to claim 7, characterized in that: The first wiring ring (75) is connected to the first conductive cover plate (2) or the second conductive cover plate (3) by a flexible connection, which is achieved by a wire (77). One end of the wire (77) is welded to the first conductive cover plate (2) and the second conductive cover plate (3), and the other end is fixedly connected to the first wiring ring (75) by a bolt.

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