Fuse capable of low-power action

Abstract

The utility model relates to the field of circuit protection, in particular to a fuse capable of performing low-power action, which comprises an electric conductor, a magnetic trigger device, an energy storage element, a cutting device and a limiting piece, and is characterized in that the electric conductor is connected with a melt in parallel, and the magnetic trigger device is mechanically linked with the limiting piece; the cutting device is arranged corresponding to the conductor; the limiting piece limits the initial position of the cutting device; when the current flowing through the conductive part exceeds a set threshold value, the magnetic triggering device is triggered, the limiting part is driven to act, limiting on the cutting-off device is relieved, the energy storage element releases stored energy to drive the cutting-off device to cut off the conductive body, and then the melt is fused. The magnetic trigger device is designed to be triggered under low current, a circuit can be cut off under low-power current for circuit protection, an energy storage element is adopted as driving force, directional impact is achieved, and the strength requirement of the shell is lowered.

Description

Technical Field

[0001] The invention relates to the field of circuit protection, in particular to a fuse capable of low-multiple operation for circuit protection. Background Art

[0002] With the development of new energy technology and the continuous advancement of energy storage battery technology, the charging current and charging voltage are constantly increasing, which puts forward the need for fuses to disconnect higher voltages and carry larger currents. According to the design principle of traditional fuses, carrying large currents requires more fuses in parallel, and the overload time of small multiples of current will be too long, which is not conducive to the protection of the circuit system. Moreover, at present, fuses that are disconnected by mechanical means generally use gas generating devices, which release a large amount of high-pressure gas as a driving force to disconnect the conductor of the fuse through ignition. For example, the small excitation fuse disclosed in Chinese patent 2021201256472, the shell and various components located around the gas generating device indiscriminately bear very large impact energy, resulting in the shell of the fuse and the various components that directly bear the impact energy. The strength requirements for bearing the impact energy are very high, otherwise, it is easy to cause the risk of shell explosion, which brings safety hazards to the use environment. Summary of the invention

[0003] The purpose of the present invention is to provide a fuse capable of low-multiple action, which can be operated at low times of rated current through a magnetic trigger device, so that the energy storage element can provide driving force in a directional manner, thereby realizing low-multiple action to cut off the fuse and perform circuit protection.

[0004] To achieve the above-mentioned purpose, the technical solution provided by the present invention is a low-power action fuse, comprising: a conductor, a magnetic trigger device, an energy storage element, a cutting device, and a limiter, wherein a fuse is connected in parallel to the conductor, and the magnetic trigger device is arranged in a magnetic field loop generated after the conductor is energized; the magnetic trigger device is mechanically linked with the limiter; and the cutting device is arranged corresponding to the conductor;

[0005] The limiting member can movably abut against the cutting device to limit the initial position of the cutting device; when the cutting device is in the initial position, the energy storage element is in an energy storage state, and the cutting device is located on the energy release path of the energy storage element in the initial state;

[0006] When the current flowing through the conductive part exceeds a set threshold, the magnetic trigger device is triggered, driving the limit member to move, causing the limit member to break away from the abutment against the cutting device, releasing the limit on the cutting device, and the energy storage element releases the stored energy to drive the cutting device to cut off the conductor, and then the fuse melts.

[0007] Preferably, the limit member can be movably located on at least one side of the cutting device, one end of the limit member abuts against the cutting device to form a limitation on the initial position of the cutting device, and the other end is located on the displacement path of the magnetic trigger device to form a linkage with the magnetic trigger device; or, the limit member is sleeved on the cutting device, abuts against the contact surface between the limit member and the cutting device to form a limitation on the initial position of the cutting device, at least one side of the outer periphery of the limit member is located on the displacement path of the magnetic trigger device to form a linkage with the magnetic trigger device; when the magnetic trigger device is actuated, the limit member can be driven to move horizontally or rotate, so that the limit member is separated from the abutment with the cutting device, thereby releasing the limitation on the initial position of the cutting device.

[0008] Preferably, the magnetic trigger device includes a dynamic magnet and a static magnet, the static magnet is arranged around the conductor, an air gap is arranged between the dynamic magnet and the static magnet, and the dynamic magnet is mechanically linked to the limit member; when the current flowing through the conductor exceeds a set threshold, the dynamic magnet moves toward the static magnet, drives the limit member to move, and releases the limit on the cutting device.

[0009] Preferably, the moving magnet is rotatably arranged relative to the static magnet, wherein one end of the moving magnet close to the static magnet is rotatably arranged on one side of the static magnet, and the other end of the moving magnet away from the static magnet is supported by a support spring and arranged at an angle on the other side of the static magnet.

[0010] Preferably, the limiting member is a circular plate-shaped structure, the cutting device is inserted into the limiting member, and the limiting member is rotatably arranged relative to the cutting device; a limiting protrusion is arranged on the outer side surface of the cutting device adjacent to the limiting member, and the limiting protrusion is located on the surface of the limiting member facing the energy storage element; a notch for the limiting protrusion to pass through is opened on the limiting member corresponding to the limiting protrusion; when the cutting device is in the initial position, the notch and the limiting protrusion are staggered, and the limiting protrusion of the cutting device abuts against the end surface of the limiting member facing the energy storage element; when the dynamic conductive magnet is displaced, the limiting member can be driven to rotate around the cutting device, so that the limiting protrusion and the notch are in a directly opposite state, thereby releasing the limitation on the cutting device.

[0011] Preferably, a movable guide rod is arranged between the moving magnet and the limit member; an abutment portion protruding from the outer periphery of the limit member is arranged on the outer periphery of the limit member, one end of the guide rod abuts against the abutment portion of the limit member, and the other end is located on the displacement path of the moving magnet, and the moving magnet is mechanically linked with the guide rod; when the current flowing through the conductive member exceeds a set threshold value, the moving magnet displaces toward the direction of the static magnet, driving the guide rod to displace, and the guide rod drives the limit member to rotate.

[0012] Preferably, the limiting member is a rod-shaped structure, one end of which abuts against an end face of the cutting device facing the conductor, and the other end is hinged to the moving magnet. The moving magnet moves toward the static magnet, driving the limiting member to move and releasing the limit on the cutting device.

[0013] Preferably, the energy storage element is a spring, one end of the spring abuts against or is connected to the cutting device, and one end away from the cutting device is fixedly arranged, and when it is in the energy storage state, the spring is in a compressed state.

[0014] Preferably, the spring is guided by means of a guide.

[0015] Preferably, the guide member is a guide ring; one end of the guide ring is fixedly arranged on the periphery of one fixed end of the spring, and the other end is located on the end face of the cutting device facing the energy storage element, and a limiting ring of the end face of the cutting device protrudes from the end face of the cutting device on the outer periphery of the guide ring. The spring is located in the guide ring and can be retracted and extended along the guide ring to drive the cutting device to move.

[0016] Preferably, a disconnection weak point is provided on the conductor, the cutting device is provided corresponding to the disconnection weak point, and the cutting device cuts off the conductor from the disconnection weak point.

[0017] Preferably, the conductor is arranged in a U-shaped structure, and the disconnection weak point is located at the bottom of the U-shaped groove of the U-shaped structure; the energy storage element, the cutting device and the limit member are respectively located in the U-shaped groove of the U-shaped structure of the conductor; the magnetic trigger device is arranged on the side walls of the U-shaped structure of the conductor; when the limit member is a rod-shaped structure, the limit member is respectively arranged between the magnetic trigger device and the cutting device; when the limit member is a circular plate-shaped structure and is rotatably mounted on the outer periphery of the cutting device, a guide rod is respectively arranged between the magnetic trigger device and the limit member.

[0018] The low-time action fuse of the present invention is designed with a magnetic trigger device that can be triggered at a low-time rated current. When a low-time overload current occurs on the conductor, the magnetic trigger device can also be triggered to cause the energy storage element to cut off the conductor, thereby reducing the safety risk that may be brought to the circuit system under a long-term low-time overload current.

[0019] The use of a magnetically triggered structure can further reduce the lower limit of the protection current, and can operate at 1.5 times the rated current or even lower, allowing the fuse to disconnect smaller currents.

[0020] By providing a directional driving force through an energy storage element, such as a spring, indiscriminate impact will not be caused to the shell and other components, the strength requirements of the shell and other components will be reduced, and the material applicability will be wider. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the principle structure when each component is in the initial position.

[0022] Figure 2 It is a schematic diagram of the principle structure after the magnetic trigger device drives the limiter to release the position limit of the cutting device.

[0023] Figure 3 It is a schematic diagram of the principle structure that after the magnetic trigger device drives the limiter to release the position limit of the cutting device, the cutting device cuts off the conductor under the drive of the energy storage element.

[0024] Figure 4 yes Figures 1 to 3 A schematic diagram of a specific structure.

[0025] Figure 5 yes Figure 4 Schematic diagram of the AA section structure.

[0026] Reference numerals:

[0027] Conductor 1, disconnect weak point 11, cutting device 2, limiting protrusion 21, energy storage element 3, limiting member 4, notch 41, melt 5, arc extinguishing chamber 51, magnetic trigger device 6, static magnet 61, dynamic magnet 62, support spring 63, guide rod 64, shell 100. DETAILED DESCRIPTION

[0028] The low-power action fuse of the present invention comprises: a conductor, a magnetic trigger device, an energy storage element, a cut-off device, and a limiter. The conductor is connected in parallel with a fuse. The magnetic trigger device is arranged in a magnetic field loop generated after the conductor is energized. The magnetic trigger device is mechanically linked with the limiter. The cut-off device is arranged corresponding to the conductor.

[0029] The limiting member can movably abut against the cutting device to limit the initial position of the cutting device; when the cutting device is in the initial position, the energy storage element is in an energy storage state, and the cutting device is located on the energy release path of the energy storage element in the initial state;

[0030] When the current flowing through the conductive part exceeds the set threshold, the magnetic trigger device is triggered, driving the limit member to move, so that the limit member is separated from the abutment against the cutting device, the limit on the cutting device is released, and the energy storage element releases the stored energy to drive the cutting device to cut off the conductor, and then the fuse melts.

[0031] With respect to the above technical solution, preferred embodiments are now cited and specifically described in conjunction with drawings.

[0032] See also Figures 1 to 3 , the conductor 1 is the main circuit of the fuse. When the fuse is connected to the circuit, under normal working conditions, the current flows through the conductor 1. A disconnection weak point 11 is provided on the conductor 1. The purpose of providing the disconnection weak point 11 is to reduce the mechanical strength of the conductor 1, so that the cutting device can cut off the conductor 1 from the disconnection weak point 11. The cutting device 2 and the energy storage element 3 are arranged on one side of the conductor 1 in sequence, and the cutting device 2 is located between the energy storage element 3 and the conductor 1. The energy storage element 3 is an elastic element, such as a spring, one end of which is fixedly arranged, and the other end is fixedly arranged on the end of the cutting device 2 away from the part of the conductor 1 to be disconnected. A limit member 4 is provided at the position of the cutting device 2, and the limit member 4 abuts against the cutting device 2 to limit the initial position of the cutting device 2. Through the initial position of the cutting device 2, a certain amount of extrusion is formed on the energy storage element 3, so that the energy storage element 3 is in an energy storage state, that is, a compressed state.

[0033] A fuse 5 is connected in parallel to the conductor 1, and the resistance of the fuse 5 is much greater than that of the conductor 1. Under normal working conditions, current flows through the conductor. Only after the conductor is disconnected, the fuse 5 forms a series circuit with the disconnected ends of the conductor, and the current flows through the fuse 5. In order to improve the breaking capacity, an arc extinguishing medium is filled at the fuse 5, so that the fuse 5 is melted in the arc extinguishing medium, thereby improving the breaking capacity.

[0034] Magnetic trigger devices 6 are symmetrically arranged on the conductor 1 on the opposite sides of the cutting device 2 and the limiter 4. The magnetic trigger device 6 includes a static magnet 61 and a dynamic magnet 62. The static magnet 61 is a semi-enclosed structure and is fixedly arranged around the conductor 1 so that the static magnet is located in the magnetic field loop generated when the conductor is energized. The dynamic magnet 62 is arranged at one end of the opening of the static magnet 61, and an air gap is reserved between the dynamic magnet and the static magnet. The purpose of the air gap is that the dynamic magnet can move toward the static magnet when it is subjected to a sufficiently large suction force from the static magnet, and is finally adsorbed by the static magnet. The dynamic magnets 62 located on the opposite sides of the limiter 4 are mechanically linked with the limiter 4 respectively.

[0035] Working principle:

[0036] Under normal working conditions, the conductor 1 is connected in series to the main circuit, and current flows through the conductor 1. Under normal working conditions, although the static magnet generates attraction on the dynamic magnet, the attraction is not enough to drive the dynamic magnet to move.

[0037] When the current is overloaded, the current flowing through the conductor 1 exceeds the set threshold value, and the suction force generated by the static magnet drives the dynamic magnet to move toward the static magnet. The displacement of the dynamic magnet on both sides of the limiter drives the limiter to move, releasing the position limit of the cutting device by the limiter. The energy storage element drives the cutting device that has lost its position limit to move toward the conductor. Under the driving force, the cutting device cuts off the conductor. The limiter can move in rotational and translational ways. After the conductor is disconnected, the current flowing through the conductor flows through the melt. Due to its high resistance, the melt limits the current. When the temperature of the melt rises to a certain value, the melt blows and completely disconnects the circuit.

[0038] With respect to the structural principle of the present invention, a preferred specific structural example is given below for illustration.

[0039] See also Figures 4 to 5 , including a shell 100 , a conductor 1 passing through the shell 100 , and a cutting device 2 , an energy storage element 3 , a stopper 4 , a melt 5 , and a magnetic trigger device 6 are all located in the shell 100 .

[0040] The conductor 1 is in a U-shaped structure, with its two ends located at the open ends of the U-shaped structure and folded to the two sides of the U-shaped structure respectively. Both ends of the conductor 1 are located at the top of the shell 100, serving as connection ends connected to the external circuit. In the U-shaped groove of the U-shaped structure of the conductor 1, a cutting device 2 and an energy storage element 3 are arranged in sequence from the bottom of the U-shaped structure of the conductor 1 toward the open end of the U-shaped structure. The limiter 4 is rotatably located in the U-shaped groove of the U-shaped structure of the conductor 1, and the limiter 4 is sleeved on the cutting device 2. A supporting structure is provided at the shell at the bottom of the U-shaped structure of the conductor 1, and the supporting structure is used to fix the conductor 1 and, at the same time, to support the limiter 4 placed thereon. A guide cavity is provided at the position of the support structure corresponding to the cutting device 2, and the cutting device 2 can pass through the limiter 4 and move along the guide cavity to the conductor 1 to cut off the conductor 1.

[0041] A disconnection weak spot is provided at the bottom of the U-shaped groove of the U-shaped structure on the conductor 1 corresponding to the impact end of the cutting device 2, so as to facilitate the cutting device 2 to disconnect the conductor 1 from the disconnection weak spot. The purpose of setting the disconnection weak spot is to reduce the mechanical strength of the conductor. Therefore, the chicken leg structure of the disconnection weak spot is a structure that can reduce the mechanical strength of the conductor, such as a U-shaped groove, a V-shaped groove, etc.

[0042] Magnetic trigger devices 6 are respectively arranged on opposite sides of the U-shaped structure of the conductor 1. The magnetic trigger device 6 includes a static magnet 61 and a dynamic magnet 62, both of which are made of magnetic conductive materials. The static magnet 61 is a semi-enclosed structure, such as a U-shaped structure, a C-shaped structure, etc. The static magnet 61 is arranged around the conductor 1, and its open end faces the outside of the U-shaped structure of the conductor 1. The static magnet 61 is supported by the inside of the shell 10. When the conductor 1 is energized, the static magnet 61 is in the magnetic field loop generated by the conductor 1. A moving magnet 62 is arranged on one side of the open end of the static magnet 61. The moving magnet 62 is arranged at an angle with the static magnet 61 or is arranged at a certain distance in parallel, so that an air gap is retained between the static magnet 61 and the moving magnet 62 components. When the static magnet 61 generates suction under the action of the magnetic field loop, and the suction can cause the moving magnet to move toward the static magnet, when it is arranged at an angle, the moving magnet moves toward the static magnet in a rotating manner, and when it is arranged in parallel, it moves toward the static magnet in a translational manner. In this embodiment, the moving magnet 62 is arranged at an angle with the static magnet 61, and the end of the moving magnet 62 closest to the static magnet 61 can be arranged in a rotatable manner, and the end with the largest distance from the static magnet 61 is supported by a support spring 63, which is used to limit the initial position of the moving magnet 62. One end of the support spring 63 is connected to the shell part on one side of the static magnet 61, and the other end is connected to the moving magnet 62. The static magnet is a yoke, and the dynamic magnet is an armature. When the static magnet 61 generates suction, and the suction is greater than the elastic force of the support spring 63, the dynamic magnet 62 will move toward the static magnet 61. A guide rod 64 is provided between the dynamic magnet 62 and the limiter 4. The guide rod 64 can be horizontally displaced through the static magnet 61, and the static magnet 61 supports and guides the guide rod. When the dynamic magnet 62 moves, it can drive the guide rod to move, and then drive the limiter to rotate through the guide rod.

[0043] The limiting member 4, in this embodiment, is a circular plate-shaped structure, which is arranged on the supporting structure. The limiting member 4 is sleeved on the outer periphery of the cutting device 2, and the limiting member 4 can be rotatably arranged horizontally between two oppositely arranged static conductive magnets 61. An arc-shaped groove is provided on the opposite side of the two static conductive magnets 61, and the opposite sides of the limiting member 4 are respectively arranged in the arc-shaped groove of the static conductive magnet 61 on the adjacent side. On the opposite sides of the limiting member 4 outside the arc-shaped groove, corresponding to the position of the guide rod 64, an abutment portion is extended outward. One end of the guide rod 64 abuts against the abutment portion of the limiting member 4, and the other end abuts against the moving conductive magnet 62. Through the action of the moving conductive magnets on the opposite sides of the limiting member, the guide rod 64 is driven to move, and then the limiting member 4 is driven to rotate around the cutting device 2. In order to improve the working reliability and the initial position limit, one end of the guide rod 64 can be hinged with the moving conductive magnet 62.

[0044] At the edge where the limiting member 4 contacts the cutting device 2, a plurality of notches 41 are arranged at intervals around the circumferential direction, and a limiting protrusion 21 is arranged correspondingly on the outer peripheral surface of the cutting device 2 corresponding to the notch 41. When the limiting protrusion 21 of the cutting device 2 is directly opposite to the notch 41 of the limiting member 4, the limiting protrusion 21 of the cutting device 2 can pass through the notch 41 under the energy storage drive of the energy storage element. In order to achieve position limitation, in the initial position, the limiting protrusion 21 of the cutting device 2 is located on the surface of the limiting member 4 facing the energy storage element 3, and is staggered with the notch 41. The limiting member 4 forms a position limitation on the cutting device 2, so that the cutting device 2 presses against the energy storage element 3 to put it in an energy storage state.

[0045] The cutting device 2 is a piston structure, and is supported by a stopper 4 to limit the initial position. A guide cavity is provided in the support structure below the stopper 4, and the impact end of the piston structure 2 is located in the guide cavity. A guide groove is provided in the guide cavity, and one end of the stopper protrusion of the piston structure 2 is located in the guide groove. The impact end of the piston structure 2 is provided opposite to the disconnection weak point of the conductor 1.

[0046] The energy storage element 3, in this embodiment, is an elastic element, such as a spring, one end of which is fixed to the top of the shell 100, and the other end is against the end face of the cutting device 2, forming an energy storage state, that is, the spring is in a compressed state. A circle of guide rings is arranged on the periphery of the energy storage element 3, which is used to limit the energy storage element to perform linear expansion and contraction. One end of the guide ring is fixedly arranged on the top of the shell 100, and the other end is located at the end face of the cutting device facing the energy storage element 3. A limiting ring with a protruding end face is arranged at the end face of the cutting device facing the energy storage element 3, and the limiting ring is located at the periphery of the guide ring. When the spring drives the cutting device to move, the spring performs a linear expansion and contraction motion along the inner wall of the guide ring, and the limiting ring of the cutting device performs a linear displacement motion along the outer periphery of the guide ring.

[0047] A melt 5 is connected in parallel to the conductor 1. The melt 5 is passed through an arc extinguishing chamber 51 provided in the housing 100, and the arc extinguishing chamber housing of the arc extinguishing chamber supports the conductor 1. A displacement channel (not shown) is provided on the arc extinguishing chamber housing for the cutting device to disconnect the conductor 1. The arc extinguishing chamber is filled with an arc extinguishing medium. The arc extinguishing medium may be solid, liquid or gas. In this embodiment, the arc extinguishing medium is quartz sand.

[0048] In some embodiments thereof, a side of the arc extinguishing chamber shell facing the conductor 1 can be deformed to form a groove-shaped structure, and the groove structure forms a displacement channel for displacement of the impact end of the cutting device 2 and the disconnected part of the conductor 1 after the conductor 1 is disconnected.

[0049] How this example works:

[0050] Under normal working conditions, current flows through the conductor 1, and the suction force generated by the static magnet of the magnetic trigger device is smaller than the elastic force of the supporting spring, so the dynamic magnet remains stationary.

[0051] When the current flowing through the conductor is overloaded and exceeds the set threshold, the suction force generated by the static magnet of the magnetic trigger device is greater than the elastic force of the supporting spring, and the dynamic magnets located on the opposite sides of the limiter are displaced toward the static magnet under the action of the suction force of the static magnet, and then the guide rod is driven to displace, and the guide rod is respectively against the abutment parts on the opposite sides of the limiter, driving the limiter to rotate relative to the cutting device. When the notch on the limiter rotates to face the limiter protrusion on the cutting device, the position limit of the cutting device by the limiter is released, and the cutting device is driven to pass through the limiter under the energy storage state of the energy storage element, that is, under the action of the spring elastic force, and the conductor is cut off along the guide cavity. After the conductor is cut off, the current flowing through the conductor flows through the melt 5. When the temperature of the melt 5 rises to a certain value, the melt 5 is melted, and the current generated by the melting of the melt 5 is extinguished by the arc extinguishing medium in the arc extinguishing chamber.

[0052] In the above embodiment, the symmetrically arranged magnetic triggering device is used to drive the guide rod, drive the limiter to rotate, and release the limit of the cutting device. The limit is released by rotating the limiter, and the impacts generated by the symmetrically arranged magnetic triggering devices can offset each other, the vibration generated is small, and the limiter rotates smoothly.

[0053] Of course, in other embodiments, the limiter can be translated or flipped to release the limit. For example, when translated, the limiter is a rod-shaped structure, which is movably arranged on the support structure in the shell. The limiter can be hinged on the moving magnet at one end, and the other end is against the end surface of the cutting device facing the conductor, forming a limit on the initial position of the cutting device. When the moving magnet is displaced, it drives the limiter to translate, break away from the conflict with the cutting device, and release the limit of the cutting device. When the limit is released, the impact caused by the magnetic trigger device may be greater than the impact caused by the rotation of the limiter in the above embodiment.

[0054] In other embodiments, the magnetic triggering device may also be arranged as a group. When arranged as a group, the vibration impact generated by the magnetic triggering device cannot be reduced, so the vibration impact is relatively large.

[0055] In the above embodiment, in order to save space, the conductor is designed to be a U-shaped structure. In other embodiments, the conductor 1 can be set to a straight-line structure.

Claims

1. A low-power fuse, characterized in that: include: An electrical conductor, a magnetic trigger device, an energy storage element, a cutting device, and a limiting member. The electrical conductor is connected in parallel with a fuse. The magnetic trigger device is arranged in a magnetic field loop generated after the electrical conductor is energized. The magnetic trigger device is mechanically linked with the limiting member. The cutting device is arranged corresponding to the electrical conductor. The limiting member can movably abut against the cutting device to limit the initial position of the cutting device; when the cutting device is in the initial position, the energy storage element is in an energy storage state, and the cutting device is located on the energy release path of the energy storage element in the initial state; When the current flowing through the conductor exceeds a set threshold, the magnetic trigger device is triggered, driving the limit member to move, causing the limit member to break away from the abutment against the cutting device, releasing the limit on the cutting device, and the energy storage element releases the stored energy to drive the cutting device to cut off the conductor, and then the fuse melts.

2. The fuse according to claim 1, characterized in that: The limiting member may be movably located at at least one side of the cutting device, one end of the limiting member abuts against the cutting device to limit the initial position of the cutting device, and the other end is located on the displacement path of the magnetic trigger device to form a linkage with the magnetic trigger device; or, the limiting member is sleeved on the cutting device, abuts against the contact surface between the limiting member and the cutting device to limit the initial position of the cutting device, at least one side of the outer periphery of the limiting member is located on the displacement path of the magnetic trigger device to form a linkage with the magnetic trigger device; when the magnetic trigger device is actuated, the limiting member may be driven to translate or rotate, so that the limiting member is separated from the abutment with the cutting device, thereby releasing the limitation on the initial position of the cutting device.

3. The fuse according to claim 2, characterized in that: The magnetic trigger device includes a dynamic magnet and a static magnet, the static magnet is arranged around the conductor, an air gap is arranged between the dynamic magnet and the static magnet, and the dynamic magnet is mechanically linked with the limiter; when the current flowing through the conductor exceeds a set threshold, the dynamic magnet moves toward the static magnet, drives the limiter to move, and releases the limit on the cutting device.

4. The fuse according to claim 3, characterized in that: The moving magnet is rotatably arranged relative to the static magnet, wherein one end of the moving magnet close to the static magnet is rotatably arranged on one side of the static magnet, and the other end of the moving magnet away from the static magnet is supported by a supporting spring and arranged at an angle on the other side of the static magnet.

5. The fuse according to claim 3, characterized in that: The limiting member is a circular plate-shaped structure, the cutting device is inserted into the limiting member, and the limiting member is rotatably arranged relative to the cutting device; a limiting protrusion is arranged on the outer side surface of the cutting device adjacent to the limiting member, and the limiting protrusion is located on the surface of the limiting member facing the energy storage element; a notch for the limiting protrusion to pass through is opened on the limiting member corresponding to the limiting protrusion; when the cutting device is in the initial position, the notch and the limiting protrusion are staggered, and the limiting protrusion of the cutting device abuts against the end surface of the limiting member facing the energy storage element; when the dynamic conductive magnet is displaced, the limiting member can be driven to rotate around the cutting device, so that the limiting protrusion and the notch are in a directly opposite state, thereby releasing the limit on the cutting device.

6. The fuse according to claim 5, characterized in that: A displaceable guide rod is arranged between the moving magnet and the limit member; an abutment portion protruding from the outer periphery of the limit member is arranged on the outer periphery of the limit member, one end of the guide rod abuts against the abutment portion of the limit member, and the other end is located on the displacement path of the moving magnet, and the moving magnet is mechanically linked with the guide rod; when the current flowing through the conductor exceeds a set threshold value, the moving magnet displaces toward the direction of the static magnet, driving the guide rod to displace, and the guide rod drives the limit member to rotate.

7. The fuse according to claim 3, characterized in that: The limiting member is a rod-shaped structure, one end of which is against an end surface of the cutting device facing the conductor, and the other end is hinged to the moving magnet.

8. The fuse according to any one of claims 1 to 7, characterized in that: The energy storage element is a spring, one end of which is against or connected to the cutting device, and one end away from the cutting device is fixedly arranged. When it is in the energy storage state, the spring is in a compressed state.

9. The fuse according to claim 8, characterized in that: The spring is guided by means of a guide.

10. The fuse according to claim 9, characterized in that: The guide member is a guide ring; one end of the guide ring is fixedly arranged on the outer periphery of the fixed end of the spring, and the other end is located on the end face of the cutting device facing the energy storage element. A limiting ring of the end face of the cutting device protrudes from the end face of the cutting device on the outer periphery side of the guide ring. The spring is located in the guide ring and can be retracted and retracted along the guide ring to drive the cutting device to move.

11. The fuse according to claim 8, characterized in that: A disconnection weak point is arranged on the conductor, the cutting device is arranged corresponding to the disconnection weak point, and the cutting device cuts off the conductor from the disconnection weak point.

12. The fuse according to claim 11, characterized in that The conductor is arranged in a U-shaped structure, and the disconnection weak point is located at the bottom of the U-shaped groove of the U-shaped structure; the energy storage element, the cutting device and the limiter are respectively located in the U-shaped groove of the U-shaped structure of the conductor; the magnetic trigger device is arranged on the side walls of the U-shaped structure of the conductor; when the limiter is a rod-shaped structure, the limiter is respectively arranged between the magnetic trigger device and the cutting device; when the limiter is a circular plate-shaped structure and is rotatably mounted on the outer periphery of the cutting device, a guide rod is respectively arranged between the magnetic trigger device and the limiter.

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