Cylinder type excitation fuse

Abstract

The invention relates to the field of circuit protection, in particular to a barrel type excitation fuse which comprises an insulating shell, a conductive barrel, a conductive end cover, an excitation source and a main piston made of insulating materials, the conductive barrel is arranged in the insulating shell in an attached mode, the conductive end cover is fixedly connected to the end of the insulating shell and seals the end of the insulating shell, and the excitation source is arranged in the main piston. The conductive end cover is in conductive contact with the conductive cylinder; the piston is located in the electric conduction barrel, the excitation source penetrates through the insulating shell and the electric conduction barrel, the driving force releasing end of the excitation source is located in the electric conduction barrel, a sealed cavity is formed between the driving force releasing end of the excitation source and the main piston, and when the excitation source acts according to a received trigger signal, driving force is released. And the main piston is driven to move along the conductive cylinder, and the conductive cylinder is disconnected. The cylindrical excitation fuse is compact in structure, small in size and high in impact resistance.

Description

Technical Field

[0001] The present invention relates to the field of circuit protection, and specifically refers to a fuse that mechanically disconnects the main circuit. Background Art

[0002] At present, most circuit protection devices that activate fuses or pyrotechnic devices adopt a multi-layer stacked manner. The most common structural form includes a housing, a conductive plate is passed through the housing, an excitation source and a piston are sequentially arranged on one side of the conductive plate, and a displacement space is provided on the other side of the conductive plate for the conductive plate to move after disconnection. In order to improve the breaking capacity, an arc extinguishing fuse is connected in parallel on the conductive plate. When an overload, short circuit or abnormal situation occurs, the excitation source can receive a trigger signal, the excitation source acts according to the received trigger signal, releases a driving force, the driving force drives the piston to displace, cuts off the conductive plate, and if there is an arc extinguishing fuse connected in parallel, the arc extinguishing fuse is cut off again.

[0003] The above structural manner mainly stacks various components in the length direction of the product, occupying a large space, so the size is relatively large. Moreover, the excitation source is generally arranged on a housing formed by processing insulating materials. Since the excitation source is a gas generating device, after receiving the trigger signal, it ignites, the gas generating agent explodes, and high-pressure gas is released as the driving force. The huge impact force generated when the excitation source releases high-pressure gas will cause a great impact on the housing, and there is a safety risk of shell cracking or even shell peeling. Therefore, very high requirements are put forward for the strength of the housing. By changing the housing material, increasing the housing thickness, or setting a protective sleeve outside the piston, etc., the impact resistance of the fuse is improved. However, no matter how it is designed, the housing, protective sleeve, etc. must be made of insulating materials, and their strength is still relatively low, and there will still be potential safety hazards. In addition, the volume of such products is large, and their installation method is different from that of traditional fuses. Due to the large volume, the miniaturization requirements for specific occasions cannot be met. Summary of the Invention

[0004] The purpose of the present invention is to provide a cylindrical excitation fuse, which uses a conductive member as a cylindrical structure, so that one end of the excitation source for releasing the driving force and the piston are located in the conductive cylinder. Through the cylindrical structure of the conductive cylinder, the huge impact brought by the excitation source for releasing the driving force is borne, avoiding the insulating housing from bearing the impact, and only the general specification requirements of the fuse need to be met for the strength of the insulating housing; at the same time, through the conductive cylinder structure, the volume of the fuse is reduced, making it adaptable to the miniaturized installation requirements.

[0005] To achieve the above purpose, the technical solution provided by the present invention is a cylindrical excitation fuse, including: an insulating housing, a conductive cylinder, a conductive end cover, an excitation source, and a main piston; the conductive end cover serves as a wiring terminal for the cylindrical excitation fuse to access the main circuit; wherein:

[0006] The conductive end caps are respectively arranged at both ends of the insulating shell, the conductive tube is inserted into the insulating shell, the conductive end caps are fixedly connected to the insulating shell or to the conductive tube, the conductive end caps seal the insulating shell, and when the conductive end caps are fixedly connected to the insulating shell, the two ends of the conductive tube are in conductive contact with the conductive end caps;

[0007] The main piston and the driving force release end of the excitation source are respectively located in the conductive cylinder, the cylinder wall of the conductive cylinder in front of the displacement path of the main piston shrinks in the radial center direction to form a force-bearing surface, and the impact end of the main piston is arranged corresponding to the force-bearing surface;

[0008] When the excitation source releases the driving force according to the received trigger signal, the main piston can be driven to move, disconnecting the conductive cylinder from the force-bearing surface, forming an insulating break between the two ends of the conductive cylinder, thereby disconnecting the main circuit.

[0009] Preferably, a disconnection weak point is provided on the force-bearing surface, and the impact end of the main piston is provided corresponding to the disconnection weak point.

[0010] Preferably, the disconnected weak point is a groove structure, and the impact end of the main piston is nested in the groove structure of the disconnected weak point.

[0011] Preferably, the wall of the conductive tube forming the force-bearing surface shrinks inwardly, and on the outer peripheral wall of the conductive tube, a groove-like structure is formed along the circumference direction of the force-bearing surface and is recessed toward the inside of the conductive tube, and the force-bearing surface is a part of the groove-like structure; an insulating ring is provided on the outer periphery of the groove-like structure, and the insulating ring is tightly matched with the insulating shell to form support for the conductive tube on both sides of the groove-like structure.

[0012] Preferably, an arc-extinguishing fuse is connected in parallel to the main circuit formed by the conductive cylinder and the conductive end cover, and the arc-extinguishing fuse is at least partially located on the displacement path of the main piston. When the main piston disconnects the conductive cylinder, the arc-extinguishing fuse is disconnected in turn.

[0013] Preferably, a first arc extinguishing chamber is provided in the conductive cylinder, the first arc extinguishing chamber is located in the portion of the conductive cylinder which is away from the direction of the main piston displacement path, the arc extinguishing fuse passes through the first arc extinguishing chamber, and the fracture formed after the arc extinguishing fuse is disconnected is located in the first arc extinguishing chamber.

[0014] Preferably, a clamping structure is provided on the main piston, and the arc-extinguishing melt is clamped in the clamping structure.

[0015] Preferably, the clamping structure is arranged on the end surface of the end of the main piston facing the stress surface of the conductive cylinder, within the area enclosed by the impact end of the main piston; a through hole for the arc extinguishing melt to pass through is formed in the clamping structure, the arc extinguishing melt is arranged in the through hole of the clamping structure, and a limiting protrusion is arranged on the arc extinguishing melt outside the clamping structure; in the initial state and normal current-carrying condition of the cartridge-type excitation fuse, the limiting protrusion restricts the relative displacement between the clamping structure and the arc extinguishing melt.

[0016] Preferably, a second arc extinguishing chamber is further arranged in the conductive cylinder, and the second arc extinguishing chamber is located in the part of the conductive cylinder in the displacement direction of the main piston, and the arc extinguishing melt passes through the second arc extinguishing chamber.

[0017] Preferably, a cover plate is arranged in the conductive cylinder, the open end of the cover plate is inserted into the conductive end cover, and the second arc extinguishing chamber is formed between the cover plate and the conductive end cover. One end of the arc extinguishing melt passes through the cover plate and the second arc extinguishing chamber and is electrically connected to the conductive end cover or the end of the conductive cylinder at the end where the second arc extinguishing chamber is located.

[0018] Preferably, a through hole is formed in the conductive end cover adjacent to the excitation source, and an indicating piston is arranged in the through hole. The through hole is communicated with the cavity where the driving force of the excitation source is released; when the excitation source releases the driving force, while driving the main piston to displace and disconnect the conductive cylinder, it also drives one end of the indicating piston to extend outside the conductive end cover.

[0019] Preferably, the excitation source is arranged through the shell wall of the insulating shell and the cylinder wall of the conductive cylinder. The signal input end of the excitation source is located on the insulating shell and can be connected to an external signal, and the driving force release end of the excitation source is located inside the conductive cylinder.

[0020] Preferably, a piston sleeve made of insulating material is sleeved on the outer periphery of the main piston. The piston sleeve is tightly fitted with the inner wall of the conductive cylinder, and the main piston can displace relative to the piston sleeve; the driving force release end of the excitation source is located in the piston sleeve, and the sealed cavity between the driving force release end of the excitation source and the main piston is located in the piston sleeve; when a through hole is formed in the conductive end cover adjacent to the excitation source and an indicating piston is arranged in the through hole, a through hole communicating with the sealed cavity where the release end of the excitation source is located is formed at the position of the piston sleeve corresponding to the indicating piston, and the through hole on the piston sleeve is communicated with the indicating piston.

[0021] Preferably, through holes are respectively formed at corresponding positions of the piston sleeve, the conductive cylinder and the insulating housing; a guide sleeve is arranged on the outer periphery of the through hole on the outer peripheral surface of the piston sleeve; the excitation source is arranged at the through hole of the piston sleeve, and a fixing member is fixedly arranged at the through holes of the guide sleeve, the conductive cylinder and the insulating housing, the fixing member fixes the excitation source, and the signal receiving end of the excitation source passes through the fixing member and is located outside the fixing member.

[0022] Preferably, two opposite and parallel planes are provided on the outer peripheral surface of the piston sleeve, and both ends of the two planes are respectively connected by arc surfaces. The guide sleeve is arranged on one of the planes, and a convex rib is arranged at one end of the other plane away from the conductive end cover. The outer periphery of the convex rib and the arc surface are in close fit with the inner wall of the conductive cylinder. The first arc extinguishing chamber is formed between the conductive cylinder, the arc surface and the convex rib, and a through hole for the arc extinguishing melt to pass through is formed on the convex rib.

[0023] Preferably, mounting screw holes are formed on the end surface of the conductive end cover.

[0024] In the tubular excitation fuse of the present invention, the conductive member is designed as a tubular structure to form a conductive cylinder. The driving force release end of the excitation source and the piston are both arranged in the conductive cylinder. The conductive cylinder bears the huge impact force generated when the excitation source releases the driving force. Since the conductive cylinder is a high-strength metal part with a certain thickness and has strong impact resistance, through the design of the conductive cylinder, while improving the impact resistance of the fuse, the requirement for the strength of the insulating housing is reduced, and the material adaptability of the insulating housing is wider. At the same time, the tubular conductive member has a large current-carrying area and strong current-carrying capacity, so that the tubular excitation fuse can be applied to working occasions with large currents. Moreover, the tubular excitation fuse can be installed by the installation method of a conventional thermal fuse, which is more convenient.

[0025] By arranging the excitation source and the piston in different positions of the fuse, and using the inner contraction of the conductive cylinder to form an annular groove structure to design the displacement space, the structure of the fuse is more compact, the structure is simpler, the volume is smaller, and it is suitable for installation and use in narrow occasions. By designing an indicating piston on the conductive end cover, after the fuse works, it can remind the operator that the circuit has a fault and needs to be repaired. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the external structure of the present invention.

[0027] Figure 2 is a schematic cross-sectional structure diagram of the present invention.

[0028] Figure 3 is a schematic diagram of the clamping structure of the main piston and the structure of the arc extinguishing melt.

[0029] Figure 4 It is a schematic structural diagram of a conductive cylinder.

[0030] Figure 5 It is Figure 4 a schematic structural diagram viewed from the front end close to the excitation source.

[0031] Figure 6 It is a schematic structural diagram of a main piston.

[0032] Figure 7 It is a schematic structural diagram of a piston sleeve.

[0033] Reference numerals:

[0034] Insulating housing 1, conductive cylinder 2, groove-like structure 21, break-weakening point 22, insulating ring 23, arc extinguishing chamber 24, cover plate 25, arc extinguishing chamber 26, through hole 27, notch 28, through hole 29, force-receiving surface 30, conductive end cap 3, mounting screw hole 31, sand filling hole 32, main piston 4, guiding portion 41, impact portion 42, impact end 43, clamping structure 44, piston sleeve 5, guiding sleeve 51, limiting convex rib 52, through hole 521, hollow portion 53, indicating piston 6, excitation source 7, fixing member 71, arc extinguishing fuse element 8, limiting projection 81. Specific embodiments

[0035] A barrel-type excitation fuse of the present invention includes: an insulating housing, a conductive cylinder, a conductive end cap, an excitation source, and a main piston; the conductive end cap serves as a wiring terminal for connecting the barrel-type excitation fuse to the main circuit; wherein:

[0036] Conductive end caps are respectively arranged at both ends of the insulating housing, the conductive cylinder is inserted into the insulating housing, the conductive end cap is fixedly connected to the insulating housing or fixedly connected to the conductive cylinder, the conductive end cap closes the insulating housing, and when the conductive end cap is fixedly connected to the insulating housing, both ends of the conductive cylinder are in conductive contact with the conductive end cap;

[0037] The main piston and the driving-force-releasing end of the excitation source are respectively located in the conductive cylinder, the barrel wall of the conductive cylinder in front of the displacement path of the main piston contracts towards the radial center to form a force-receiving surface, and the impact end of the main piston is arranged corresponding to the force-receiving surface;

[0038] When the excitation source acts according to the received trigger signal to release the driving force, it can drive the main piston to displace, break the conductive cylinder at the force-receiving surface, and form an insulating break between both ends of the conductive cylinder, thereby disconnecting the main circuit.

[0039] For the above technical solutions, preferred embodiments are now given and specifically described in conjunction with the drawings. Refer to Figures 1 to 3 , wherein:

[0040] The insulating housing 1 is made of insulating material and is formed by braiding, injection molding, sintering, etc. The material is preferably PA66 + 30% glass fiber or high-temperature resistant nylon and is formed by braiding. The insulating housing 1 is mainly used for the insulation protection and support fixation of the entire fuse and does not need to bear impact force. The insulating housing 1 is a cylindrical structure with both ends penetrating, and through holes are provided on the housing wall near one end of the insulating housing 1.

[0041] Conductive end caps 3 are fixedly connected to both ends of the insulating housing 1 respectively, and the conductive end caps 3 seal both ends of the insulating housing 1. The conductive end caps 3 are connected and fixed to the insulating housing 1 by riveting or other means. The conductive end caps 3 serve as the wiring terminals for energizing the fuse and can be connected to the protected electrical circuit.

[0042] Mounting screw holes 31 and sand filling holes 32 are provided on the conductive end cap 3. The mounting screw holes 31 are used for the conductive connection of the protected electrical circuit, and the sand filling holes 32 are used for filling the arc extinguishing medium. An indicating through hole for indication that penetrates the thickness of the conductive end cap 3 is also provided on the conductive end cap 3, and the indicating through hole communicates the hollow part of the conductive cylinder 2 and the outside of the insulating housing 1. The indicating through hole has a limiting step, and an indicating piston 6 is arranged in the indicating through hole inside the conductive end cap 3, and the indicating piston 6 is in interference fit with the indicating through hole. When the indicating piston 6 is impacted, the end facing the outside of the insulating housing 1 extends out of the insulating housing 1 for reminder. When the indicating piston displaces, the limiting step in the indicating through hole limits the displacement position of the indicating piston 6 to prevent it from flying out of the insulating housing.

[0043] The conductive cylinder 2, see Figure 4 , is made of conductive material, preferably aluminum alloy or pure aluminum with high conductivity. The conductive cylinder 2 is a cylindrical structure and is arranged in the insulating housing 1, closely attached to the inner wall of the insulating housing 1. The cylindrical structure can include a circular cylinder, a square cylinder or a cylindrical structure with other cross-sectional shapes. The radial cross-section of the conductive cylinder 2 is preferably a non-angular shape such as a circle or an ellipse, or the radial cross-section of the conductive cylinder is a cylindrical structure with rounded corners. The non-angular conductive cylinder 2 can avoid the occurrence of stress concentration points, and combined with the material of the conductive cylinder, the conductive cylinder has the highest strength and can withstand the impact force when the excitation source ignites and releases high-pressure gas. In this embodiment, the conductive cylinder 2 is an integrally formed structure and its radial cross-section is circular.

[0044] The conductive cylinder 2 is located between the conductive end caps 3 at both ends of the insulating housing 1, and the conductive cylinder 2 is electrically connected to the conductive end caps 3. The conductive cylinder 2 and the conductive end caps 3 are electrically connected by crimping, riveting, welding or other means.

[0045] The barrel wall between the two ends of the conductive barrel 2 contracts towards the radial center of the conductive barrel at appropriate positions, forming a concave groove-like structure 21 along the circumferential direction on the outer periphery of the conductive barrel 2. The appropriate positions refer to that the space size inside the conductive barrel on one side of the groove-like structure 21 must be sufficient to accommodate the excitation source, the main piston, and the piston sleeve. One side of the groove-like structure 21 forms a stress surface 30, which is perpendicular to the axis of the conductive barrel 2. See Figure 5 At the stress surface 30, disconnection weak points 22 are arranged at intervals along the circumferential direction of the conductive barrel 2, and through holes 29 penetrating the stress surface 30 are provided between adjacent disconnection weak points 22. The purpose of setting the disconnection weak points 22 is to disconnect the conductive barrel from the disconnection weak points 22 under the impact of the main piston, so that the two ends of the conductive barrel are disconnected and in an insulated state. Therefore, no matter where the disconnection weak points are set and what their structural forms are, their purpose is to facilitate the main piston to disconnect the conductive barrel from the disconnection weak points 22, forming an insulated fracture at both ends of the conductive barrel, and making both ends of the conductive barrel in an insulated and non-conductive state. The structure of the disconnection weak points 22 aims to reduce the mechanical strength of the stress surface to facilitate disconnection when being impacted. The structure of the disconnection weak points 22 can be a groove structure, a thinning structure, a lap joint structure, etc. structures that reduce mechanical strength. The groove structure can be a flat-bottom groove, a U-shaped groove, a V-shaped groove, etc. In this embodiment, the disconnection weak points 22 are set as a groove structure.

[0046] An insulating ring 23 is sleeved on the outer periphery of the groove-like structure 21. The insulating ring 23 is closely fitted with the inner wall of the insulating housing 1. The insulating ring 23 supports and fixes the conductive barrel parts on both sides of the groove-like structure 21 to improve the mechanical strength at the groove-like structure. At the same time, the width of the groove-like structure serves as a displacement space for the piston impact end to displace after disconnecting the conductive barrel from the disconnection weak point at the stress surface.

[0047] A through hole 27 is provided on the conductive barrel 2 for one end of the driving force release of the excitation source 7 to pass through, and notches 28 are respectively provided on the end walls at both ends of the conductive barrel 2 for both ends of the arc extinguishing melt 8 to be erected and fixed.

[0048] In this embodiment, the conductive barrel is an integrally formed structure. In other embodiments, the conductive barrel can be formed by welding two parts. For example, the conductive barrel is divided into two parts at the groove-like structure 21. One end inner wall of the conductive barrel part where the main piston is arranged extends towards the radial center direction to form a stress surface, and disconnection weak points are designed at the stress surface. The other end of the conductive barrel part contracts inward along the radial direction, and then the two parts are welded, welding the contracted end with the end provided with the stress surface to form an integral conductive barrel.

[0049] An excitation source 7, a main piston 4, and a piston sleeve 5 are arranged inside the conductive barrel 21 on the side where the stress surface 30 is provided.

[0050] The main piston 4, see Figure 6, it is integrally in a convex structure, including a guiding part 41 with a small outer diameter and an impact part 42 with a large outer diameter. A piston sleeve 5 is sleeved on the outer periphery of the guiding part 41. At the end face of the impact part 42 facing the force-receiving surface 30, there is a corresponding break-weakened part 22, which extends towards the break-weakened part 22, forming an impact end 43 protruding from the end face of the impact part 42. The impact ends 43 are arranged in one-to-one correspondence with the break-weakened parts 22. The purpose is that when the piston is impacted and displaced, the impact end 43 can break the conductive cylinder from the break-weakened part 22, making both ends of the conductive cylinder in an insulated and non-conductive state. The impact end 43 of the main piston 4 is nested in the open end of the groove structure of the break-weakened part 22, and the initial position of the piston is supported by the break-weakened part 22. A certain gap is reserved between the impact end 43 of the main piston and the bottom of the groove structure of the break-weakened part 22.

[0051] On the end face of the main piston 4 where the impact end 43 is provided, there is also a clamping structure 44. In this embodiment, the clamping structure 44 is located within the end face area enclosed by the impact end 43, that is, the impact end 43 is located on the outer peripheral side of the clamping structure 44. In other embodiments, as long as the structural shape permits, the clamping structure 44 can also be located outside the end face area enclosed by the impact end 43. The existence, position, and structure of the clamping structure 44 are designed on the principle of not affecting the movement of the impact end 43. The structure of the clamping structure 44 is: a convex block is provided on the impact end face of the main piston, and a through hole for the arc-extinguishing melt 8 to pass through is provided on the convex block, and the through hole penetrates both sides of the convex block. A through hole 45 penetrating the thickness of the impact part 42 is opened on the impact part 42 on one side of the clamping structure 44 of the main piston 4. After the arc-extinguishing melt 8 passes through the main piston 4 through the through hole 45, it then passes through the through hole on the clamping structure 44.

[0052] The piston sleeve 5, see Figure 7 , its interior is a hollow part 53 that matches the outer periphery of the guiding part 41 of the main piston. One end of the hollow part 53 penetrates one end face of the piston sleeve 5 to form an open end, and the other end of the piston sleeve 5 is closed. The open end of the piston sleeve 5 is sleeved on the outer periphery of the guiding part 41 of the main piston, and the closed end abuts against the conductive end cover 3. The size of the gap at the contact surface between the main piston 4 and the piston sleeve 5 satisfies that the driving force released by the excitation source can drive the main piston to break the conductive cylinder and break the arc-extinguishing melt. It is also possible to seal the contact surface between the main piston 4 and the piston sleeve 5, specifically by setting a sealing ring on the outer periphery of the main piston 4. A through hole is opened at one end of the piston sleeve 5 in contact with the conductive end cover 3, and this through hole is communicated with the through hole of the indicating piston 6 provided at the conductive end cover.

[0053] Piston sleeve 5, in which the two opposite outer sides are parallel plane structures, and the other two opposite outer sides are arc-shaped surface structures, that is, the two ends of the two parallel plane structures are respectively connected by arc-shaped surfaces, and the arc-shaped surfaces match the shape of the inner wall of the conductive cylinder. When the piston sleeve is arranged in the conductive cylinder, the arc-shaped surfaces can be closely attached to the inner wall of the conductive cylinder. After the piston sleeve 5 is sleeved on the main piston 4, the outer side of its arc-shaped surface structure is closely matched with the inner wall of the conductive cylinder, and a gap is reserved between the outer side of the plane structure and the inner wall of the conductive cylinder. A guide sleeve 51 is arranged on one of the plane structures, and the guide sleeve 51 is correspondingly arranged with the through hole on the insulating housing 1. An excitation source 7 is arranged in the guide sleeve 51, and the excitation source 7 is pressed by a fixing member 71 arranged in the guide sleeve 51. One end of the fixing member 71 is located in the guide sleeve 51, and the other end sequentially passes through the through holes of the conductive cylinder and the insulating housing and is located at the through hole of the insulating housing 1. The driving force release end of the excitation source 7 is located in the cavity between the main piston 4 and the end of the piston sleeve 5, and the signal receiving end of the excitation source 7 passes through the fixing member 7 and is located outside the fixing member 7, and can be communicated with the outside of the insulating housing 1.

[0054] The excitation source 7 is a gas generating device, which can ignite according to the trigger signal received by the signal receiving end and release high-pressure gas as the driving force. When the excitation source 7 receives the trigger signal and acts to release the driving force, both the main piston 4 and the indicating piston 6 will be impacted and displaced by the driving force. The main piston 4 displaces to cut off the weak part 22, thereby disconnecting the conductive cylinder 2. The indicating piston 6 is impacted, and one end extends out of the insulating housing to give an action reminder. The excitation source 7 is arranged on the shell wall in the radial direction of the fuse, and the main piston is arranged in the axial direction of the fuse, avoiding the superimposed arrangement of the excitation source and the main piston, making reasonable use of space and reducing space occupation.

[0055] On the plane structure on the other side of the piston sleeve 5 where the guide sleeve 51 is not arranged, at one end close to the impact end of the main piston, a limiting convex rib 52 extends towards the inner wall side of the conductive cylinder 2. The outer periphery of the limiting convex rib 52 is an arc-shaped surface, which is closely attached to the inner wall of the conductive cylinder. A first arc extinguishing chamber 24 is formed by the limiting convex rib 52, the plane structure on one side of the piston sleeve, the conductive end cover, and the inner wall of the conductive cylinder. The first arc extinguishing chamber 24 is filled with arc extinguishing medium. A through hole 521 for the arc extinguishing melt to pass through is opened on the limiting convex rib 52, and the notch 28 at the end of the conductive cylinder 2 is located at the first arc extinguishing chamber 24.

[0056] At the other end of the conductive cylinder 2 where the main piston is not provided, a second arc extinguishing chamber 26 is formed by arranging a cover plate 25. The cover plate 25 has a cover-like structure. One end of the opening of the cover plate 25 is inserted into the adjacent conductive end cover 3 to form the second arc extinguishing chamber 26, and an arc extinguishing medium is filled in the second arc extinguishing chamber 26. The arc extinguishing media in the first arc extinguishing chamber 24 and the second arc extinguishing chamber 26 are solid arc extinguishing substances, preferably quartz sand, or can also be a liquid arc extinguishing medium, such as a liquid gel. The other end of the cover plate 25 abuts against the other side of the groove-like structure 21 of the conductive cylinder 2, that is, the inner wall of the conductive cylinder on the other side opposite to the weak disconnection point, to form the positioning of the cover plate 25.

[0057] The sand filling holes 32 on the conductive end cover 3 are located at the first arc extinguishing chamber 24 and the second arc extinguishing chamber 26. The arc extinguishing medium is filled into the first arc extinguishing chamber 24 and the second arc extinguishing chamber 26 through the sand filling holes, and the sand filling holes are sealed with plugs.

[0058] The arc extinguishing melt 8, the two ends of which are respectively electrically connected to the two ends of the conductive cylinder 2, is connected in parallel with the conductive cylinder 2. The arc extinguishing melt 8 passes through the first arc extinguishing chamber 24, the limiting rib 52 of the piston sleeve 5, the main piston 4, the through hole of the clamping structure 44, the cover plate 25 and the second arc extinguishing chamber 26. After passing through the main piston 4, the arc extinguishing melt 8 is arranged in the through hole on the clamping structure 44. A limiting protrusion 81 is arranged on the arc extinguishing melt 8 on one side of the through hole of the clamping structure 44, and the limiting protrusion 81 is clamped outside the through hole of the clamping structure 44. When the main piston 4 starts to displace, relative displacement between the main piston 4 and the arc extinguishing melt 8 can be prevented, ensuring that the main piston 4 can break the arc extinguishing melt 8.

[0059] When the main piston 4 displaces, the conductive cylinder 2 is disconnected first, and then the arc extinguishing melt 8 is disconnected. In order to make the fracture of the arc extinguishing melt 8 disconnected mechanically by the main piston 4 be located in the first arc extinguishing chamber 24, arc extinguishing is carried out through the arc extinguishing medium in the first arc extinguishing chamber 24. A weak disconnection point is arranged on the arc extinguishing melt 8 in the first arc extinguishing chamber 24, and the function of the weak disconnection point is the same as that of the weak disconnection point on the conductive cylinder.

[0060] A fusing neck is also arranged on the arc extinguishing melt 8 in the first arc extinguishing chamber 24 and the second arc extinguishing chamber 26. The fracture generated by the thermal melting and fusing of the arc extinguishing melt 8 can be located in the first arc extinguishing chamber 24 or in the second arc extinguishing chamber 26.

[0061] The resistance of the arc extinguishing melt 8 is much greater than the resistance of the conductive cylinder 2 to ensure that under normal working conditions, the current flows through the conductive cylinder 2.

[0062] Working principle:

[0063] Under normal working conditions, the current mainly flows through the conductive cylinder, and only a very small part flows through the arc extinguishing melt.

[0064] In case of overload current, short circuit or abnormal conditions, the excitation source operates according to the received trigger signal, releases high-pressure gas as the driving force, and drives the main piston 4 and the indicating piston 6 to displace respectively. The displacement of the main piston 4 cuts off the weak break 22 on the conductive cylinder 2, and disconnects the protected electrical circuit. At the moment when the weak break 22 is disconnected, the current flows through the arc extinguishing melt 8. During the process of the main piston 4 displacing to disconnect the conductive cylinder 2, the clamping structure on the main piston 4 displaces accordingly. Due to the existence of the limiting protrusion on the arc extinguishing melt 8, the clamping structure 44 pulls the arc extinguishing melt 8. After the conductive cylinder 2 is disconnected, as the displacement distance of the main piston 4 increases, the clamping structure 44 breaks the arc extinguishing melt 8 from the weak break of the arc extinguishing melt 8, so that the fracture of the arc extinguishing melt 8 is located in the first arc extinguishing chamber 24, and an arc is generated at the fracture of the arc extinguishing melt 8 to extinguish the arc through the arc extinguishing medium.

[0065] When the overload or short circuit is a large current, after the conductive cylinder is disconnected, the arc extinguishing melt 8 may first fuse from the narrow neck. Since the narrow neck of the arc extinguishing melt 8 is located in the first arc extinguishing chamber and the second arc extinguishing chamber, the fracture of the arc extinguishing melt 8 when it fuses is also located in the first arc extinguishing chamber and the second arc extinguishing chamber, and the arc generated by the fusing also extinguishes the arc through the arc extinguishing medium.

[0066] The trigger signal received by the above excitation source can be sent by an external control system or by an internal trigger circuit integrated on the fuse. Principle of the internal trigger circuit sending the trigger signal: Detect whether the current flowing through the conductive cylinder exceeds the set threshold. If it exceeds, turn on the internal trigger circuit to send a trigger signal to the excitation source.

[0067] The inner wall shape of the above conductive cylinder only needs to ensure the smooth displacement of the main piston.

[0068] In the above embodiment, a piston sleeve is provided. In other embodiments, the piston sleeve may not be provided. The excitation source is provided on the insulating housing and the conductive cylinder, the main piston is directly provided on the inner wall of the conductive cylinder, and the main piston is in sealed contact with the inner wall of the conductive cylinder. The sealed contact method includes setting a sealing ring on the outer periphery of the main piston or the main piston being closely fitted with the inner wall of the conductive cylinder and other methods. When the main piston is driven by the driving force, the main piston can displace. The radial cross-sectional shape of the inner wall of the conductive cylinder is preferably helpful for the smooth displacement of the main piston, such as a circular structure.

[0069] The insulating housing and the conductive cylinder are tubular structures. In addition to the circular tubular structure in the above embodiment, it can also be a square tube structure, a tubular structure with a polygonal radial cross-section, a tubular structure with an elliptical radial cross-section, etc.

[0070] The above piston, piston sleeve, and fixing member for fixing the excitation are all made of insulating materials, preferably PA66 + 30% glass fiber or high-temperature resistant nylon materials, and the indicating piston is made of insulating material.

[0071] In the present invention, the conductive member of the actuating fuse is designed as a cylindrical structure, and at the same time, one end of the actuating source for releasing the driving force and the main piston are designed inside the conductive cylinder. By utilizing the high mechanical strength characteristics of the conductive cylinder made of metal, the impact resistance of the fuse is improved, the strength requirement for the insulating housing is reduced, and the range of materials applicable to the insulating housing is widened.

[0072] The actuating source and the main piston are misaligned and designed inside the conductive cylinder, making full use of the space and making the structure more compact.

[0073] By using the appearance structure design of the piston sleeve, an arc extinguishing chamber is formed with the conductive cylinder and the conductive end cover, making full use of the existing components to form the first arc extinguishing chamber and improving the utilization rate of the components.

[0074] By designing a clamping structure for the arc extinguishing melt on the main piston and using the small displacement space of the piston to cut off the conductive cylinder to break the melt, it is avoided to additionally design a melt breaking component and a displacement space for the arc extinguishing melt to break. While reducing the number of fuse components, the product volume is further reduced.

[0075] By the support of the groove at the weak breakage part of the conductive cylinder for the impact end of the main piston, it is avoided to design a limiting structure for limiting the initial position of the main piston, simplifying the product structure.

[0076] In summary, the actuating fuse of the present invention has few components, is simple to assemble, small in volume, strong in impact resistance, and has a low strength requirement for the insulating housing.

Claims

1. A cartridge-type excitation fuse, characterized in that, It includes: an insulating shell, a conductive cylinder, a conductive end cover, an excitation source, and a main piston; the conductive end cover serves as a terminal for connecting the cylinder excitation fuse to the main circuit; wherein: The conductive end caps are respectively arranged at both ends of the insulating shell, the conductive tube is inserted into the insulating shell, the conductive end caps are fixedly connected to the insulating shell or to the conductive tube, the conductive end caps seal the insulating shell, and when the conductive end caps are fixedly connected to the insulating shell, the two ends of the conductive tube are in conductive contact with the conductive end caps; The main piston and the driving force release end of the excitation source are respectively located in the conductive cylinder, the cylinder wall of the conductive cylinder in front of the displacement path of the main piston shrinks in the radial center direction to form a force-bearing surface, and the impact end of the main piston is arranged corresponding to the force-bearing surface; When the excitation source releases the driving force according to the received trigger signal, the main piston can be driven to move, disconnecting the conductive cylinder from the force-bearing surface, forming an insulating break between the two ends of the conductive cylinder, thereby disconnecting the main circuit.

2. The cartridge fuse according to claim 1, characterized in that, A disconnected weak point is arranged on the force-bearing surface, and the impact end of the main piston is arranged corresponding to the disconnected weak point.

3. The cartridge fuse according to claim 2, wherein, The disconnected weak point is a groove structure, and the impact end of the main piston is nested in the groove structure of the disconnected weak point.

4. The cartridge fuse according to claim 1, characterized in that, The wall of the conductive tube that forms the force-bearing surface shrinks inwardly, and on the outer peripheral wall of the conductive tube, a groove-like structure is formed along the circumference direction of the force-bearing surface and is recessed toward the inside of the conductive tube. The force-bearing surface is a part of the groove-like structure. An insulating ring is sleeved on the outer periphery of the groove-like structure, and the insulating ring is tightly matched with the insulating shell to form support for the conductive tube on both sides of the groove-like structure.

5. The cartridge fuse according to claim 1, wherein An arc-extinguishing fuse is connected in parallel to the main circuit formed by the conductive cylinder and the conductive end cover. The arc-extinguishing fuse is at least partially located on the displacement path of the main piston. When the main piston disconnects the conductive cylinder, the arc-extinguishing fuse is disconnected in turn.

6. The cartridge fuse according to claim 5, wherein, A first arc extinguishing chamber is provided in the conductive cylinder. The first arc extinguishing chamber is located in a portion of the conductive cylinder that is away from the displacement path of the main piston. The arc extinguishing fuse passes through the first arc extinguishing chamber. A fracture formed after the arc extinguishing fuse is disconnected is located in the first arc extinguishing chamber.

7. The cartridge fuse according to claim 5, wherein, A clamping structure is arranged on the main piston, and the arc-extinguishing melt is clamped in the clamping structure.

8. The cartridge fuse according to claim 7, characterized in that, The clamping structure is arranged on the end surface of one end of the main piston facing the force-bearing surface of the conductive cylinder, and is located in the area surrounded by the impact end of the main piston; a through hole for the arc-extinguishing fuse to pass through is opened on the clamping structure, and the arc-extinguishing fuse is inserted into the through hole of the clamping structure, and a limiting protrusion is arranged on the arc-extinguishing fuse outside the clamping structure; when the cylinder-type excitation fuse is in the initial state and normal current flow, the limiting protrusion limits the relative displacement between the clamping structure and the arc-extinguishing fuse.

9. The cartridge fuse according to claim 6, wherein A second arc extinguishing chamber is also provided in the conductive cylinder. The second arc extinguishing chamber is located in the conductive cylinder portion in the displacement direction of the main piston, and the arc extinguishing melt passes through the second arc extinguishing chamber.

10. The cartridge fuse according to claim 9, characterized in that, A cover plate is arranged in the conductive cylinder. The open end of the cover plate is inserted into the conductive end cover, and the second arc extinguishing chamber is formed between the cover plate and the conductive end cover. One end of the arc extinguishing melt passes through the cover plate and the second arc extinguishing chamber and is electrically connected to the conductive end cover or the end of the conductive cylinder at the end where the second arc extinguishing chamber is located.

11. The cartridge fuse according to claim 1, characterized in that, A through hole is provided on the conductive end cover adjacent to the excitation source. An indicating piston is arranged in the through hole, and the through hole is communicated with the cavity where one end of the excitation source releases driving force. When the excitation source releases driving force, while driving the main piston to displace and disconnect the conductive cylinder, it also drives one end of the indicating piston to extend outside the conductive end cover.

12. The cartridge fuse according to claim 1, characterized in that, The excitation source is arranged through the wall of the insulating housing and the wall of the conductive cylinder. The signal input end of the excitation source is located on the insulating housing and can be connected to an external signal. The driving force release end of the excitation source is located inside the conductive cylinder.

13. The cartridge fuse according to any one of claims 1 to 12, characterized in that, An insulating piston sleeve is sleeved on the outer periphery of the main piston. The piston sleeve is tightly fitted with the inner wall of the conductive cylinder, and the main piston can displace relative to the piston sleeve. The driving force release end of the excitation source is located in the piston sleeve, and the sealed cavity between the driving force release end of the excitation source and the main piston is located in the piston sleeve. When a through hole is provided on the conductive end cover adjacent to the excitation source and an indicating piston is arranged in the through hole, a through hole communicating with the sealed cavity where the release end of the excitation source is located is provided at the position of the piston sleeve corresponding to the indicating piston, and the through hole on the piston sleeve is communicated with the indicating piston.

14. The cartridge fuse according to claim 13, wherein Through holes are respectively provided at corresponding positions of the piston sleeve, the conductive cylinder and the insulating housing. A guide sleeve is arranged at the outer periphery of the through hole on the outer peripheral surface of the piston sleeve. The excitation source is arranged at the through hole of the piston sleeve, and a fixing member is fixedly arranged at the through holes of the guide sleeve, the conductive cylinder and the insulating housing. The fixing member fixes the excitation source, and the signal receiving end of the excitation source passes through the fixing member and is located outside the fixing member.

15. The cartridge fuse according to claim 14, characterized in that, Two opposite and parallel planes are provided on the outer peripheral surface of the piston sleeve. The two ends of the two planes are respectively connected by arc surfaces. A guide sleeve is arranged on one plane, and a convex rib is arranged at one end of the other plane away from the conductive end cover. The outer periphery of the convex rib and the arc surfaces are tightly attached to the inner wall of the conductive cylinder. The first arc extinguishing chamber is formed between the conductive cylinder, the arc surfaces and the convex rib. A through hole for the arc extinguishing melt to pass through is provided on the convex rib.

16. The cartridge fuse according to claim 1, characterized in that, Mounting screw holes are provided on the end face of the conductive end cover.

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