Excitation fuse with cylindrical structure

Abstract

The invention relates to the field of circuit protection, in particular to an excitation fuse with a cylindrical structure, which comprises an insulating shell, a conductive cylinder, a conductive end cover, an excitation source, a main piston made of an insulating material, an arc extinguishing melt and a melt disconnecting assembly, the conductive cylinder is attached in the insulating shell, and the conductive end cover is fixedly connected to the end part of the insulating shell and is in conductive contact with the conductive cylinder; the driving force releasing end of the excitation source and the main piston are located in the conductive cylinder, the main piston is provided with a hollow part, and the arc extinguishing melt penetrates through the hollow part of the main piston and is connected to the two ends of the conductive cylinder in parallel. The melt disconnecting assembly is arranged in the hollow part of the main piston, and after the driving force released by the excitation source drives the main piston to displace and cuts off the conductive cylinder, the melt disconnecting assembly is driven to disconnect the arc extinguishing melt. The excitation fuse is high in impact resistance, low in requirement for the strength of the insulating shell, small in size and small in use requirement.

Description

Technical Field

[0001] The present invention relates to the field of circuit protection, and particularly to an excitation fuse with a cylindrical structure that mechanically disconnects the main circuit. Background Art

[0002] At present, most circuit protection devices excited by excitation 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 for the conductive plate after disconnection is arranged on the other side of the conductive plate. In order to improve the breaking capacity, an arc extinguishing melt is connected in parallel on the conductive plate. When overload, short circuit or abnormal conditions occur, 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 melt connected in parallel, cuts off the arc extinguishing melt 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 a 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 are safety risks such as shell cracking or even shell peeling. Therefore, very high requirements are imposed on 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 relatively low, and there will still be potential safety hazards. In addition, the volume of this type of product is large, and its 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 object of the present invention is to provide an excitation fuse with a cylindrical structure, which uses a conductive member as the cylindrical structure, so that one end where the excitation source releases the driving force and the main piston are located in the conductive cylinder; at the same time, a hollow part is arranged in the main piston, and the melt disconnection assembly is arranged in the hollow part of the main piston. Through the cylindrical structure of the conductive cylinder, the huge impact brought by the release of the driving force of the excitation source is borne, the impact resistance of the product is improved, and at the same time, the internal space of the main piston is utilized to avoid the melt disconnection assembly occupying extra space, while reducing the strength requirements for the insulating housing, and minimizing the volume of the excitation fuse to make it more adaptable to the miniaturization installation requirements.

[0005] To achieve the above object, the technical solution provided by the present invention is an excitation fuse in a cylindrical structure, including an insulating housing, a conductive cylinder, a conductive end cap, an excitation source, a main piston made of insulating material, an arc extinguishing melt, and a melt disconnection assembly; the conductive end cap serves as a wiring terminal for connecting the excitation fuse in the cylindrical structure to the main circuit, wherein:

[0006] The conductive cylinder is fitted in the insulating housing, the conductive end cap is fixedly connected to the end of the insulating housing and closes the end of the insulating housing, and the conductive end cap is in conductive contact with the conductive cylinder;

[0007] One end of the driving force release of the excitation source and the main piston are respectively located in the conductive cylinder, the main piston is in close contact with the conductive cylinder, and a sealed cavity is formed among the conductive end cap, the excitation source, the main piston and the conductive cylinder;

[0008] Both ends of the arc extinguishing melt are conductively connected to both ends of the conductive cylinder in parallel, or both ends of the arc extinguishing melt are conductively connected to the conductive end caps at both ends of the insulating housing;

[0009] The main piston is provided with a hollow part, and the arc extinguishing melt passes through the hollow part of the main piston; a melt disconnection assembly is arranged in the hollow part, and the arc extinguishing melt is located on the displacement path of the melt disconnection assembly; in the initial state, the cavity where the melt disconnection assembly is located is not communicated with the cavity where one end of the driving force release of the excitation source is located, and the opening between the cavity where the melt disconnection assembly is located and the cavity where one end of the driving force release of the excitation source is located is on the displacement path of the main piston;

[0010] When the excitation source acts according to the received trigger signal, releases the driving force, and drives the main piston to displace along the conductive cylinder and disconnect the conductive cylinder; during the displacement of the main piston, the cavity where the melt disconnection assembly is located is communicated with the cavity where one end of the driving force release of the excitation source is located, and after the main piston disconnects the conductive cylinder, the driving force released by the excitation source drives the melt disconnection assembly to disconnect the arc extinguishing melt.

[0011] Preferably, the hollow part penetrates through both ends in the displacement direction of the main piston; an arc extinguishing cavity is provided in the hollow part, the arc extinguishing melt passes through the arc extinguishing cavity, the melt disconnection assembly is arranged in the arc extinguishing cavity and is communicated with the hollow part, and an arc extinguishing medium is filled in the arc extinguishing cavity outside the melt disconnection assembly;

[0012] Under the driving force released by the excitation source, the main piston displaces along the conductive cylinder and the arc extinguishing chamber and disconnects the conductive cylinder; during the displacement of the main piston, the melt disconnection assembly communicates with the cavity where one end of the driving force release of the excitation source is located. After the main piston disconnects the conductive cylinder, the driving force released by the excitation source drives the melt disconnection assembly to disconnect the arc extinguishing melt.

[0013] Preferably, the arc extinguishing chamber includes a first arc extinguishing chamber and a second arc extinguishing chamber. One end where the first arc extinguishing chamber and the second arc extinguishing chamber are adjacent abuts against each other, and the non-adjacent ends are respectively in contact with the conductive end caps located at both ends of the insulating housing; the first arc extinguishing chamber is disposed through the hollow portion; the arc extinguishing melt passes through the first arc extinguishing chamber and the second arc extinguishing chamber; the melt disconnection assembly is disposed in the first arc extinguishing chamber.

[0014] Preferably, the first arc extinguishing chamber and the second arc extinguishing chamber respectively include a first arc extinguishing housing and a second arc extinguishing housing with one end open. The open end of the second arc extinguishing housing is inserted into the conductive end cap, and the open end of the first arc extinguishing housing is in contact with the conductive end cap; the non-open ends of the first arc extinguishing housing and the second arc extinguishing housing abut against each other; a sand filling hole is formed in the conductive end cap, and the sand filling hole communicates with the first arc extinguishing chamber and the second arc extinguishing chamber, and the sand filling hole is sealed by a plug.

[0015] Preferably, the barrel wall of the conductive cylinder in front of the displacement path of the main piston contracts radially inward to form an annular groove, and a breakage weak point is provided on the barrel wall of the conductive cylinder corresponding to the impact end side of the main piston.

[0016] Preferably, the breakage weak point is a groove structure, and the impact end of the main piston is nested in the groove structure of the breakage weak point.

[0017] Preferably, an insulating ring is sleeved on the outer periphery of the annular groove formed at the place where the barrel wall of the conductive cylinder contracts inward, and the insulating ring is in interference fit with the insulating housing to form support for the conductive cylinder on both sides of the annular groove.

[0018] Preferably, the excitation source is disposed on the wall of the insulating housing and the barrel wall of the conductive cylinder; the excitation source is located between the conductive end cap and the other end opposite to the impact end of the main piston.

[0019] Preferably, fixing members are fixedly provided on the wall of the insulating housing and the barrel wall of the conductive cylinder, and the excitation source is disposed on the fixing members.

[0020] Preferably, a through hole is provided in the conductive end cover adjacent to the driving force release end of the excitation source. An indicating piston is arranged in the through hole. When the excitation source releases the driving force, one end of the indicating piston can be driven to extend outside the conductive end cover for fault warning.

[0021] Preferably, the main piston includes a protruding portion, a sealing portion and an impact portion which are integrally connected. The protruding portion and the impact portion are respectively located at both ends of the sealing portion. The outer peripheral surface of the sealing portion is attached to the inner wall of the conductive cylinder. There is a gap between the protruding portion and the impact portion and the inner wall of the conductive cylinder. The hollow portion penetrates through the protruding portion, the sealing portion and the impact portion. An impact end extends from the free end surface of the impact portion on the outer periphery of the hollow portion.

[0022] Preferably, mounting screw holes are provided on the end surface of the conductive end cover.

[0023] Preferably, the melt-disconnecting assembly includes a guiding cylinder and a melt-disconnecting piston. The melt-disconnecting piston is arranged in the guiding cylinder. The arc-extinguishing melt passes through the guiding cylinder. When the main piston is displaced, one end of the guiding cylinder where the melt-disconnecting piston is located can be communicated with the chamber where the driving force release end of the excitation source is located. After the main piston disconnects the conductive cylinder, the driving force released by the excitation source can drive the melt-disconnecting piston to displace along the guiding cylinder to disconnect the arc-extinguishing melt.

[0024] For the tubular structure excitation fuse of the present invention, the conductive member is designed as a conductive cylinder with a tubular structure. The driving force release end of the excitation source and the piston are both arranged inside 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 member with a certain thickness and has a 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 conductive member with a tubular structure has a large current-carrying area and a strong current-carrying capacity, so that the tubular excitation fuse can be applied to working occasions with large currents. Moreover, the tubular structure excitation fuse can be installed by the installation method of a conventional thermal fuse, which is more convenient.

[0025] The main piston is designed as a hollow structure, and a melt-disconnecting assembly is arranged in the main piston, effectively utilizing the internal space of the main piston without additionally occupying the internal volume of the product, making the product volume smaller.

[0026] By adopting the misaligned arrangement of the excitation source and the piston, 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, and the volume is smaller.

[0027] By designing an indicating piston on the conductive end cover, after the fuse operates, it can remind the operator that there is a circuit fault and maintenance is required.

[0028] In summary, the cartridge-type actuating fuse of the present invention has strong impact resistance, low strength requirements for the insulating shell, small volume, and is more suitable for installation in narrow spaces. Brief Description of the Drawings

[0029] Figure 1 It is a schematic diagram of the external structure of the present invention.

[0030] Figure 2 It is a schematic cross-sectional structure diagram of the present invention.

[0031] Figure 3 It is a schematic diagram of the conductive cylinder structure.

[0032] Figure 4 It is a schematic diagram of the conductive cylinder structure from another perspective of the conductive cylinder.

[0033] Figure 5 It is a schematic diagram of the main piston structure.

[0034] Reference Signs:

[0035] Insulating shell 1, conductive end cover 10, mounting screw hole 101, sand filling hole 102, indicating piston 103, conductive cylinder 2, annular groove 21, breakage weak point 22, insulating ring 23, through hole 24, notch 25, through hole 29, actuating source 3, fixing member 31, main piston 4, sealing portion 41, protruding portion 42, impact portion 43, impact end 44, hollow portion 45, first arc extinguishing chamber 5, first arc extinguishing housing 51, guiding cylinder 52, second arc extinguishing chamber 6, second arc extinguishing housing 61, melt breaking piston 7, arc extinguishing melt 8. Detailed Description of the Invention

[0036] An actuating fuse with a cartridge-type structure of the present invention includes an insulating shell, a conductive cylinder, a conductive end cover, an actuating source, a main piston made of insulating material, an arc extinguishing melt, and a melt breaking assembly; the conductive end cover serves as a wiring terminal for connecting the actuating fuse with a cartridge-type structure to the main circuit, wherein:

[0037] The conductive cylinder is disposed in the insulating shell in a fitting manner, the conductive end cover is fixedly connected to the end of the insulating shell and closes the end of the insulating shell, and the conductive end cover is in conductive contact with the conductive cylinder;

[0038] One end where the driving force of the actuating source is released and the main piston are respectively located in the conductive cylinder, the main piston is in close contact with the conductive cylinder, and a sealed cavity is formed among the conductive end cover, the actuating source, the main piston and the conductive cylinder;

[0039] Both ends of the arc extinguishing melt are conductively connected to both ends of the conductive cylinder in parallel, or both ends of the arc extinguishing melt are conductively connected to the conductive end caps at both ends of the insulating housing;

[0040] The main piston is provided with a hollow part, and the arc extinguishing melt passes through the hollow part of the main piston; a melt breaking component is arranged in the hollow part, and the arc extinguishing melt is located on the displacement path of the melt breaking component; in the initial state, the cavity where the melt breaking component is located is not communicated with the cavity where one end of the driving force of the excitation source is released, and the opening between the cavity where the melt breaking component is located and the cavity where one end of the driving force of the excitation source is released is located on the displacement path of the main piston;

[0041] When the excitation source acts according to the received trigger signal, releases the driving force, and drives the main piston to displace along the conductive cylinder and disconnect the conductive cylinder; during the displacement of the main piston, the cavity where the melt breaking component is located is communicated with the cavity where one end of the driving force of the excitation source is released, and after the main piston disconnects the conductive cylinder, the driving force released by the excitation source drives the melt breaking component to disconnect the arc extinguishing melt.

[0042] For the above technical solutions, preferred embodiments are now given and specifically described in conjunction with the drawings. Refer to Figures 1 to 4 , where:

[0043] The insulating housing 1 is made of insulating material, and is formed by braiding, injection molding or 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 overall fuse, and does not need to bear impact force. The insulating housing 1 is of a cylindrical structure with both ends penetrating, and a through hole is opened on the shell wall near one end of the insulating housing 1.

[0044] The conductive cylinder 2, refer to Figures 2 to 4 , is made of conductive material, preferably aluminum alloy or pure aluminum with high conductivity. The conductive cylinder 2 is of an integrally formed structure in this embodiment, is inserted into the insulating housing 1, and is arranged in an interference fit with the insulating housing 1. Conductive end caps 10 are respectively arranged at both ends of the conductive cylinder 2 in a conductive contact manner, and the conductive end caps 10 are connected and fixed to the ends of the insulating housing 1 by means of crimping, riveting or welding, etc. The conductive end caps 10 seal both ends of the insulating housing 10. The conductive end caps 10 serve as the connection ends for exciting the fuse, and mounting screw holes 101 for external connection and installation are opened on the conductive end caps 10 for the installation of the exciting fuse and the conductive connection with the external circuit.

[0045] The conductive cylinder 2 has a cylindrical structure, which may include a circular cylinder, a square cylinder, or a cylindrical structure with other cross-sectional shapes. Its radial cross-section 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 shape avoids 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. The inner wall shape of the conductive cylinder can ensure the smooth displacement of the main piston. In this embodiment, its radial cross-section is circular.

[0046] The central part of the conductive cylinder 2 in the length direction contracts towards the radial center, forming a concave annular groove 21. The cylinder wall of the conductive cylinder 2 on one side of the annular groove 21 is a planar structure, and this planar structure is perpendicular to the axis of the conductive cylinder. Refer to Figure 4 , at this planar structure, discontinuous weak points 22 are arranged at intervals in the circumferential direction, and through holes 29 penetrating this planar structure are provided between adjacent discontinuous weak points 22. The purpose of setting the discontinuous weak points 22 is to break the conductive cylinder at the discontinuous weak points 22 under the impact of the main piston, so that the two ends of the conductive cylinder are disconnected and in an insulated state. Therefore, no matter where the discontinuous weak points are set and what their structural forms are, their purpose is to facilitate the piston to break the conductive cylinder at the discontinuous weak points 22, so that its two ends are in an insulated and non-conductive state. The structure of the discontinuous weak points 22 aims to reduce the mechanical strength of the cylinder wall of the conductive cylinder at this place to facilitate disconnection when impacted. The structure of the discontinuous weak points 22 can be a groove structure, a thinning structure, a lapping structure, etc. 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 discontinuous weak points 22 are set as a groove structure.

[0047] An insulating ring 23 is sleeved on the outer periphery of the annular groove 21, and the insulating ring 23 is provided with an interference fit with the inner wall of the insulating housing 1 to support and fix the conductive cylinder parts on both sides of the annular groove 21. Through holes 24 are opened on the cylinder wall of the conductive cylinder 2 corresponding to the through holes of the insulating housing for installing the excitation source. Notches 25 for fixing both ends of the fixed arc extinguishing melt 8 are respectively opened on the end faces of both ends of the conductive cylinder 2.

[0048] In this embodiment, the conductive cylinder is of an integrally formed structure. In other embodiments, the conductive cylinder can be formed by welding or splicing two parts. For example, along the length direction of the conductive cylinder at the annular groove 21, the conductive cylinder is divided into two parts: the first conductive cylinder part and the second conductive cylinder part. The main piston, the excitation source, the melt-disconnecting piston, and the guide cylinder are all arranged in the first conductive cylinder part. One end of the first conductive cylinder part away from the conductive end cover is bent inward to form an annular bending part, and the bending part is perpendicular to the axis of the conductive cylinder. Disconnection weak points are arranged at intervals on the bending part, through holes are formed between adjacent disconnection weak points, and the impact end of the main piston corresponds to the disconnection weak point on the bending part. One end of the second conductive cylinder part is in conductive contact with the conductive end cover, and the other end shrinks inward to form a shrinking end. The shrinking end of the second conductive cylinder part is welded to the bending part of the first conductive cylinder part to form an annular groove 21 on the outer periphery of the conductive cylinder.

[0049] Alternatively, the shrinking end of the second conductive cylinder part is turned outwards to form a flange. The first conductive cylinder part and the second conductive cylinder part are butted, and the edge of the bending part of the first conductive cylinder part overlaps at the flange turned outwards at the shrinking end of the second conductive cylinder part. By fixing the two conductive end covers at both ends, the butted conductive cylinder is formed. An insulating ring 23 is sleeved at the annular groove 21 formed by the first conductive cylinder part and the second conductive cylinder part, and the insulating ring 23 and the conductive end cover form the support and fixation for the first conductive cylinder part and the second conductive cylinder part.

[0050] There are also many other structural forms of the conductive cylinder, as long as it can insulate the outer shell and fix the conductive end cover, can be disconnected by the main piston, will not displace relative to the main piston, and can be in conductive contact with the conductive end cover.

[0051] An excitation source 3 and a main piston 4 are arranged inside the conductive cylinder 2 on the side where the disconnection weak point 22 is provided. A fixing member 31 is fixedly arranged in the through hole of the insulating outer shell and the through hole 24 of the conductive cylinder. The excitation source 3 is arranged on the fixing member 31. The signal receiving end of the excitation source 3 can be connected to the outside of the insulating outer shell 1, and the driving force release end of the excitation source 3 is located inside the conductive cylinder 2. The main piston 4 is arranged in the conductive cylinder 2. The driving force release end of the excitation source 3 is located between the main piston 4 and the conductive end cover 10, and the impact end of the main piston 4 corresponds to the disconnection weak point 22 of the conductive cylinder 2.

[0052] The main piston 4, see Figure 2 and Figure 5, it is an integrally formed structure, including a sealing portion 41, and protruding portions 42 and impact portions 43 located on both sides of the sealing portion. The sealing portion 41 of the main piston 4 is in contact with the inner wall of the conductive cylinder 2. The contact method can be that the outer peripheral surface shape of the sealing portion 41 is the same as the inner wall shape of the conductive cylinder, so that the sealing portion 41 is fitted on the inner wall of the conductive cylinder. Or, a sealing ring is provided on the outer peripheral surface of the sealing portion 41 to achieve close contact between the main piston and the conductive cylinder. Or, the sealing portion 41 and the inner wall of the conductive cylinder are in interference fit. The maximum outer diameters of the protruding portion 42 and the impact portion 43 are both smaller than the maximum outer diameter of the sealing portion 41.

[0053] The protruding portion 42 faces the conductive end cover 10 side, and the impact portion 43 faces the breakage-weak part 22 side of the conductive cylinder. A hollow portion 45 is provided in the main piston 4, and the hollow portion 45 penetrates both ends in the displacement direction of the main piston 4, that is, the hollow portion 45 penetrates the protruding portion 42, the sealing portion 41 and the impact portion 43. The impact portion 43 is an annular structure and is provided on one end face of the sealing portion 41. The hollow portion 45 is located in the annular impact portion 43. The impact portion 43 includes impact ends 44 arranged at intervals along the circumferential direction, and the impact ends 44 are arranged corresponding to the breakage-weak part 22 of the conductive cylinder 2. When the breakage-weak part 2 is a groove structure, the impact ends 44 are nested at the opening of the groove structure, and a certain gap is left between the impact ends 44 and the groove bottom of the breakage-weak part 22 of the conductive cylinder to increase the impact kinetic energy. One end face of the sealing portion 41 of the main piston 4 abuts against the fixing member 31 at the excitation source 3. By the impact ends 44 being nested at the breakage-weak part of the conductive cylinder 2 and the abutment between the fixing member 31 and the end face of the sealing portion 41 of the main piston 4, the initial position of the main piston 4 is defined. An approximately sealed cavity is formed among the driving force release end of the excitation source 3, the conductive end cover, the conductive cylinder, and the main piston 4.

[0054] A first arc extinguishing chamber 5 is disposed through the hollow portion of the main piston 4. The hollow portion of the main piston 4 is in contact with the first arc extinguishing chamber 5, and the main piston 4 can displace along the conductive cylinder and the first arc extinguishing chamber 5. The first arc extinguishing chamber 5 includes a first arc extinguishing housing 51 with one end open. The open end of the first arc extinguishing housing 51 is in contact with the conductive end cover 10 close to it to form the first arc extinguishing chamber 5. The material of the first arc extinguishing housing 51 is a self-lubricating flame-retardant insulating material, which can ensure good lubrication of the main piston 4 while meeting the structural strength and electrical performance, and avoid jamming.

[0055] A second arc extinguishing chamber 6 is provided between the first arc extinguishing chamber 5 and the other conductive end cover. One end of the second arc extinguishing chamber 6 is in contact with the first arc extinguishing chamber 6, and the other end is in contact with the conductive end cover.

[0056] The second arc extinguishing chamber 6 includes a second arc extinguishing housing 61 with an open end. The second arc extinguishing housing 61 is arranged in fit with the inner wall of the conductive cylinder. Its open end is inserted into the conductive end cap 10 at the other end, and the other end opposite to the open end abuts against the bending part of the conductive cylinder on the other side of the arc-shaped groove 21. The position of the second arc extinguishing housing 61 is defined by the conductive cylinder, its bending part, and the conductive end cap. The second arc extinguishing chamber is formed by the conductive end cap and the second arc extinguishing housing. Sand filling holes 102 are respectively opened on the conductive end caps where the first arc extinguishing chamber 5 and the second arc extinguishing chamber 6 are located. Arc extinguishing media are filled into the first arc extinguishing chamber 5 and the second arc extinguishing chamber 6 respectively through the sand filling holes 102. The arc extinguishing media are preferably quartz sand. After the sand filling is completed, the sand filling holes are blocked with plugs.

[0057] A melt breaking component is arranged in the first arc extinguishing chamber 5 located in the hollow part of the main piston 4. The melt breaking component includes a displacement guiding cylinder 52 and a melt breaking piston 7. The length direction of the displacement guiding cylinder 52 is perpendicular to the displacement direction of the main piston 4. A guiding channel penetrating through both ends is opened in the displacement guiding cylinder 52, and a limiting step is arranged in the guiding channel. A melt breaking piston 7 is arranged in the guiding channel at a certain distance from the limiting step. The melt breaking piston 7 is in interference fit with the guiding channel of the displacement guiding cylinder. A through hole is opened on the first arc extinguishing housing 51 corresponding to the melt breaking piston 7, and the through hole is communicated with the guiding channel. This through hole is the opening for the communication between the chamber where the melt breaking component is located and the chamber at the driving force release end of the excitation source. In the initial position, the main piston 4 seals the through hole opened on the first arc extinguishing housing 51 corresponding to the melt breaking piston 7, so the chamber where the melt breaking piston is located is not communicated with the chamber at the driving force release end of the excitation source; when the main piston 4 displaces and disconnects the displacement of the conductive cylinder 2, the through hole opened on the first arc extinguishing housing 51 corresponding to the melt breaking piston 7 is gradually exposed to the cavity at the driving force release end of the excitation source, and the chamber where the melt breaking piston is located is gradually communicated with the chamber at the driving force release end of the excitation source until it is completely communicated. During this process, the driving force acting on the melt breaking piston 7 gradually increases. When the main piston 4 disconnects the conductive cylinder 2, the driving force acting on the melt breaking piston 7 can drive the melt breaking piston 7 to displace, so as to break the arc extinguishing melt 8.

[0058] The arc extinguishing melt 8 passes through the first arc extinguishing chamber 5, the guiding cylinder 52, and the second arc extinguishing chamber 6, and its two ends are electrically connected to both ends of the conductive cylinder. The arc extinguishing melt 8 is located on the displacement path of the melt breaking piston 7. At least one breaking weak point and several fusing necks are arranged on the arc extinguishing melt 8. The breaking weak point is located in the first arc extinguishing chamber 5, and the fusing necks are located in the first arc extinguishing chamber 5 and the second arc extinguishing chamber 6. The resistance of the arc extinguishing melt 8 is much greater than that of the conductive cylinder. In the normal working state, almost all the current flows through the conductive cylinder, and only a very small part flows through the arc extinguishing melt.

[0059] In the initial position, i.e., in the normal working state, the main piston 4 closes the through hole on the first arc extinguishing housing 51 corresponding to the melt-breaking piston 7. When the main piston 4 is driven to displace by the driving force released by the excitation source, the main piston 4 displaces along the conductive cylinder and the first arc extinguishing housing 51. As the main piston 4 displaces, the through hole on the first arc extinguishing housing 51 corresponding to the melt-breaking piston 7 gradually changes from being non-communicating to being completely communicating with the cavity where one end of the driving force released by the excitation source is located. When the main piston 4 displaces to disconnect the conductive cylinder, the through hole on the first arc extinguishing housing 51 corresponding to the melt-breaking piston 7 is completely communicating with the cavity where one end of the driving force released by the excitation source is located. At this time, the driving force received by the melt-breaking piston 7 is the largest. Under the action of the driving force released by the excitation source, the melt-breaking piston 7 displaces after overcoming the limitation of the interference fit, disconnecting the arc extinguishing melt 8. After disconnecting the arc extinguishing melt 8, the limiting step in the guiding channel limits the displacement distance of the melt-breaking piston 7. The mechanical fracture of the arc extinguishing melt 8 is located in the arc extinguishing medium of the first arc extinguishing chamber 5.

[0060] A through hole is provided on the conductive end cap 10 on the side close to the excitation source 3. An indicating piston 103 is arranged in the through hole. The through hole where the indicating piston 103 is located is communicating with the cavity where one end of the driving force released by the excitation source is located. The material of the indicating piston is an insulating material. The driving force released by the excitation source 3 can drive one end of the indicating piston 103 to extend out of the outside of the insulating housing 1 for warning reminder, indicating that the circuit has a fault and needs to be repaired.

[0061] Working principle:

[0062] Under normal working conditions, the current mainly flows through the conductive cylinder, and only a very small part flows through the arc extinguishing melt.

[0063] In case of overload current, short circuit or abnormal situation, the excitation source acts according to the received trigger signal, releases high-pressure gas as the driving force, and drives the main piston 4 and the indicating piston 103 to displace respectively. The main piston 4 displaces along the conductive cylinder 2 and the first arc extinguishing chamber 5, cuts off the weak breaking part 22 of the conductive cylinder 2, disconnects the conductive cylinder, thus disconnecting the main circuit. Then, the current flows through the arc extinguishing melt 8. During the displacement process of the main piston 4 to disconnect the conductive cylinder 2, the through hole opened on the first arc extinguishing housing 51 corresponding to the melt-breaking piston 7 is gradually exposed to the cavity where one end of the driving force released by the excitation source is located and gradually communicates with the cavity until it is completely communicating. After the main piston 4 disconnects the conductive cylinder 2, the driving force drives the melt-breaking piston 7 to displace, disconnecting the arc extinguishing melt 8. The fracture of the arc extinguishing melt 8 is located in the first arc extinguishing chamber 5. The arc generated at the fracture of the arc extinguishing melt 8 is extinguished by the arc extinguishing medium, realizing zero-current cut-off of the main circuit.

[0064] 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. The principle of the internal trigger circuit for sending the trigger signal is to detect whether the current flowing through the conductive cylinder exceeds the set threshold. If it exceeds, the internal trigger circuit is turned on to send a trigger signal to the excitation source.

[0065] In addition to the hollow cylindrical structure, the insulating housing and the conductive cylinder can also be hollow square structures, elliptical structures, etc.

[0066] The above-mentioned 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. The indicating piston is made of insulating material.

[0067] Through the tubular structure design of the conductive cylinder, the main piston and the driving force release end of the excitation source are respectively designed inside the conductive cylinder. The conductive cylinder made of metal and with high mechanical strength improves the impact resistance of the product and reduces the strength requirements for the insulating housing.

[0068] At the same time, the main piston is designed as a hollow structure, and the melt-breaking component is designed in the hollow structure of the main piston. By making full use of the volume of the main piston and the displacement characteristics after receiving the driving force, while reducing the volume, the sequential actions of the main piston and the melt-breaking piston are realized. Through the structural design of the conductive cylinder and the main piston, the space is fully utilized, the volume is reduced, the structure is more compact, and it is more suitable for miniaturized places.

Claims

1. An excitation fuse with a barrel structure, characterized in that, It includes an insulating housing, a conductive cylinder, a conductive end cap, an excitation source, a main piston made of insulating material, an arc extinguishing melt, and a melt disconnection component; the conductive end cap serves as the terminal for connecting the barrel-type excitation fuse to the main circuit, where: The conductive cylinder is fitted in the insulating housing, the conductive end cap is fixedly connected to the end of the insulating housing and closes the end of the insulating housing, and the conductive end cap is in conductive contact with the conductive cylinder; One end for releasing the driving force of the excitation source and the main piston are respectively located in the conductive cylinder, the main piston is in close contact with the conductive cylinder, and a sealed cavity is formed among the conductive end cap, the excitation source, the main piston and the conductive cylinder; Both ends of the arc extinguishing melt are conductively connected to both ends of the conductive cylinder in parallel, or both ends of the arc extinguishing melt are conductively connected to the conductive end caps at both ends of the insulating housing; The main piston is provided with a hollow part, and the arc extinguishing melt passes through the hollow part of the main piston; a melt disconnection component is arranged in the hollow part, and the arc extinguishing melt is located on the displacement path of the melt disconnection component; in the initial state, the chamber where the melt disconnection component is located is not communicated with the cavity where one end for releasing the driving force of the excitation source is located, and the opening between the chamber where the melt disconnection component is located and the chamber where one end for releasing the driving force of the excitation source is located is on the displacement path of the main piston; When the excitation source acts according to the received trigger signal, releases the driving force, and drives the main piston to displace along the conductive cylinder and disconnect the conductive cylinder; during the displacement of the main piston, the chamber where the melt disconnection component is located is communicated with the cavity where one end for releasing the driving force of the excitation source is located, and after the main piston disconnects the conductive cylinder, the driving force released by the excitation source drives the melt disconnection component to disconnect the arc extinguishing melt.

2. The cartridge-type structure excitation fuse according to claim 1, characterized in that, The hollow part penetrates through both ends in the displacement direction of the main piston; An arc extinguishing chamber is penetrated in the hollow part, the arc extinguishing melt passes through the arc extinguishing chamber, the melt disconnection component is arranged in the arc extinguishing chamber and is communicated with the hollow part, and an arc extinguishing medium is filled in the arc extinguishing chamber other than the melt disconnection component; Under the action of the driving force released by the excitation source, the main piston displaces along the conductive cylinder and the arc extinguishing chamber and disconnects the conductive cylinder; during the displacement of the main piston, the melt disconnection component is communicated with the cavity where one end for releasing the driving force of the excitation source is located, and after the main piston disconnects the conductive cylinder, the driving force released by the excitation source drives the melt disconnection component to disconnect the arc extinguishing melt.

3. The cartridge fuse with a cylindrical structure according to claim 2, characterized in that, The arc extinguishing chamber includes a first arc extinguishing chamber and a second arc extinguishing chamber, one end where the first arc extinguishing chamber and the second arc extinguishing chamber are adjacent to each other abuts against each other, and the non-adjacent ends are respectively in contact with the conductive end caps at both ends of the insulating housing; the first arc extinguishing chamber is penetrated in the hollow part; the arc extinguishing melt passes through the first arc extinguishing chamber and the second arc extinguishing chamber; the melt disconnection component is arranged in the first arc extinguishing chamber.

4. The cartridge fuse of the cartridge structure according to claim 3, characterized in that, The first arc extinguishing chamber and the second arc extinguishing chamber respectively include a first arc extinguishing housing and a second arc extinguishing housing with one end open. The open end of the second arc extinguishing housing is inserted into the conductive end cover, and the open end of the first arc extinguishing housing is in contact with the conductive end cover; the non-open ends of the first arc extinguishing housing and the second arc extinguishing housing are abutted against each other; a sand filling hole is formed in the conductive end cover, and the sand filling hole communicates with the first arc extinguishing chamber and the second arc extinguishing chamber, and the sand filling hole is sealed by a plug.

5. The cartridge fuse with a cylindrical structure according to claim 1, characterized in that, The wall of the conductive cylinder in front of the displacement path of the main piston contracts towards the radial center to form an annular groove, and a breaking weak point is arranged on the wall of the conductive cylinder on the side corresponding to the impact end of the main piston.

6. The cartridge fuse with a tubular structure according to claim 5, characterized in that, The breaking weak point is a groove structure, and the impact end of the main piston is nested in the groove structure of the breaking weak point.

7. The cartridge fuse with a cylindrical structure according to claim 5, characterized in that, An insulating ring is sleeved on the outer periphery of the annular groove formed at the place where the wall of the conductive cylinder contracts inwards, and the insulating ring is in interference fit with the insulating housing to form support for the conductive cylinder on both sides of the annular groove.

8. The cartridge-type structure excitation fuse according to claim 1, characterized in that, The excitation source is arranged on the wall of the insulating housing and the wall of the conductive cylinder; the excitation source is located between the conductive end cover and the other end opposite to the impact end of the main piston.

9. The cartridge fuse of the cartridge structure according to claim 8, characterized in that, Fixing members are fixedly arranged on the wall of the insulating housing and the wall of the conductive cylinder, and the excitation source is arranged on the fixing members.

10. The cartridge fuse with a cylindrical structure according to claim 1, characterized in that, A through hole is formed in the conductive end cover adjacent to the driving force release end of the excitation source, and an indicating piston is arranged in the through hole. When the excitation source releases the driving force, one end of the indicating piston can be driven to extend out of the conductive end cover for fault warning.

11. The fuse with excitation of the cartridge structure according to claim 1, characterized in that The main piston includes a protruding part, a sealing part and an impact part which are integrally connected. The protruding part and the impact part are respectively located at both ends of the sealing part. The outer peripheral surface of the sealing part is attached to the inner wall of the conductive cylinder, and there are gaps between the protruding part and the impact part and the inner wall of the conductive cylinder; the hollow part penetrates through the protruding part, the sealing part and the impact part; an impact end extends from the free end surface of the impact part on the outer periphery of the hollow part.

12. The cartridge-type structure excitation fuse according to claim 1, wherein Mounting screw holes are formed on the end surface of the conductive end cover.

13. The cartridge fuse with a cylindrical structure according to any one of claims 1 to 12, characterized in that, The melt breaking assembly includes a guiding cylinder and a melt breaking piston. The melt breaking piston is arranged in the guiding cylinder, and the arc extinguishing melt passes through the guiding cylinder. When the main piston is displaced, one end of the guiding cylinder where the melt breaking piston is located can communicate with the chamber where the driving force release end of the excitation source is located. After the main piston breaks the conductive cylinder, the driving force released by the excitation source can drive the melt breaking piston to displace along the guiding cylinder to break the arc extinguishing melt.

Images