Self-excitation fuse capable of improving heat-conducting property

Abstract

A self-excitation fuse capable of improving heat conduction performance comprises a high-heat-conduction, high-strength and insulating shell, a first conductor, a signal melt, a conducting bar, a second conductor, an arc extinguishing melt, an ignition device and a cutting piece, a displacement channel with one open end and the other closed end is arranged in the shell, the open end is located at the shell wall of the shell, a heat-conducting arc extinguishing medium is filled between the displacement channel and the shell, the signal melt, the arc extinguishing melt and the conducting bar are located in the arc extinguishing medium, and the conducting bar penetrates through the displacement channel; the ignition device is in threaded connection with the opening end of the displacement channel, and the cut-off piece is located in the displacement channel; the arc extinguishing melt is connected in parallel to the conducting bar; the signal melt and the ignition device are connected in series in the self-excitation trigger loop, the signal melt is conducted, the self-excitation trigger loop is not conducted, and when the signal melt is fused, the self-excitation trigger loop is conducted to send a trigger signal to the ignition device. Heat is dissipated through the shell and the arc extinguishing medium, and the ignition device is convenient to replace.

Description

Technical Field

[0001] This invention relates to the field of fuses, and more particularly to a self-excited fuse with improved thermal conductivity. Background Technology

[0002] A self-excited fuse is a fast-cutting fuse containing an excitation device. Typically, a signal fuse element is connected in series in a conductor bar, and an ignition device is connected in parallel across the signal fuse element via a self-excited circuit. When a fault current is generated and the signal fuse element melts, an arc is formed at the melt point, causing a momentary voltage increase that activates the self-excited circuit, providing a trigger signal to the ignition device. The ignition device then activates, releasing high-pressure gas to drive a piston displacement, which in turn cuts off the conductor bar and the circuit.

[0003] In energized or self-energized fuses, to avoid affecting piston movement and the displacement of the disconnected portion of the conductor bus after it is broken, no arc-extinguishing medium is placed around the outer periphery of the conductor bus. The arc-extinguishing medium is only placed around the outer periphery of the arc-extinguishing molten metal connected in parallel to the conductor bus to participate in arc extinguishing after the molten metal breaks.

[0004] Currently, these self-excited fuses typically have low resistance and low power consumption. However, since the fuse housing is usually made of plastic, and plastic has poor heat dissipation, the heat generated by the conductor busbar must be relatively small. Therefore, the conductor busbar needs to meet the requirements of large current carrying capacity, thick copper busbar, and small neck for easy cutting. This undoubtedly increases the material cost and manufacturing difficulty of the conductor busbar. At the same time, since the ignition device is designed inside the product, after a long time, the internal gunpowder may become damp or undergo decomposition reaction due to various reasons, causing the gunpowder to fail. In this case, the entire product needs to be replaced before it can be used normally, resulting in material waste. Summary of the Invention

[0005] The purpose of this invention is to improve the heat dissipation performance of the product by detachably mounting the ignition device of the self-excited fuse on the outside of the product housing, and by combining it with a heat-conducting shell and an arc-extinguishing medium, while also facilitating the replacement of the ignition device.

[0006] To achieve the above objectives, the present invention provides a self-excited fuse with improved thermal conductivity, comprising a highly thermally conductive, high-strength, and insulating outer shell, a first conductor, a signal fuse, a conductive busbar, and a second conductor connected in series, an arc-extinguishing fuse, an ignition device, and a cutting element; the first and second conductors are respectively disposed within the outer shell as the connection ends of the self-excited fuse; a displacement channel with one open end and the other closed is provided within the outer shell, the open end of the displacement channel being located at the shell wall and communicating with the outside, and the closed end of the displacement channel being located within the outer shell; an arc-extinguishing chamber filled with a thermally conductive arc-extinguishing medium is provided between the displacement channel and the outer shell, and the arc-extinguishing medium is in direct contact with the outer shell; the signal fuse, the arc-extinguishing fuse, and the conductive busbar are located within the outer shell. In the arc-extinguishing medium, the conductive busbar passes through the displacement channel; the ignition device is located outside the housing and is fixed at the opening end of the displacement channel by a threaded connection; the cutting element is located in the displacement channel between the conductive busbar and the ignition device; the arc-extinguishing melt is connected in parallel to the conductive busbar on both sides of the displacement channel; the conductive circuit where the signal melt is located is conductively connected to the trigger signal receiving end of the ignition device to form a self-excited triggering circuit. When the signal melt is on, the self-excited triggering circuit is not on; when the signal melt melts, the self-excited triggering circuit is on, sending a trigger signal to the ignition device. The ignition device actuates, driving the cutting element to move along the displacement channel to cut the conductive busbar, after which the arc-extinguishing melt melts.

[0007] Preferably, the arc-extinguishing melt is a curved structure that bends away from the conductive busbar.

[0008] Preferably, the arc-extinguishing melt is disposed across the closed end of the displacement channel.

[0009] Preferably, the conductive busbar is provided with a weak break point, the weak break point is located in the displacement channel, and the cutting element is provided corresponding to the weak break point.

[0010] Preferably, the outer shell comprises a first shell, a second shell, and a third shell assembled sequentially, the displacement channel is located in the first shell and the second shell, the open end of the displacement channel is located at the shell wall of the first shell, and the closed end of the displacement channel is located in the second shell; the first conductor, the second conductor, and the conductive busbar are respectively located between the first shell and the second shell; the arc extinguishing chamber is formed inside the first shell, the second shell, and the third shell.

[0011] Preferably, the second housing on opposite sides of the conductive busbar is provided with a plurality of legs extending toward the conductive busbar, and the legs abut against the opposite sides of the conductive busbar.

[0012] Preferably, the narrow neck of the arc-extinguishing melt is provided with a mounting hole, which is inserted through the support leg.

[0013] Preferably, the inner wall of the displacement channel is provided with a limiting groove, and the outer periphery of the cutting member is provided with a limiting protrusion corresponding to the limiting groove, and the limiting protrusion of the cutting member is engaged in the limiting groove in the displacement channel.

[0014] Preferably, a gap is provided between the limiting groove and the limiting protrusion.

[0015] Preferably, the second conductor and the conductive busbar are electrically connected by bolts, or the second conductor and the conductive busbar are integrally formed.

[0016] Preferably, the first housing, the second housing, and the third housing are fixed together by bolts, the first conductor is fixed together with the second housing and the third housing by threads, and one end of the second conductor connected to the conductive busbar is fixed together with the second housing by bolts.

[0017] The self-excited fuse of the present invention facilitates replacement when the ignition device fails by placing the ignition device outside the housing and fixing it to the housing by a threaded connection.

[0018] At the same time, the use of a highly thermally conductive and insulated shell that is in direct contact with a highly thermally conductive arc-extinguishing medium is beneficial for heat conduction and dissipation, thereby reducing the overall temperature of the product.

[0019] The shell material of the present invention is a highly thermally conductive and high-strength insulating material, such as ceramic or other materials with high thermal conductivity, high strength and insulation; the arc-extinguishing medium is an arc-extinguishing medium made of highly thermally conductive and insulating materials such as quartz sand and alumina powder.

[0020] Moreover, since the arc-extinguishing medium is in direct contact with the inner wall of the shell, that is, the cavity area inside the shell except for the displacement channel is filled with the arc-extinguishing medium. The arc-extinguishing melt and the conductive busbar are both set in the arc-extinguishing medium in the same arc-extinguishing chamber, which saves the need for a separate arc-extinguishing chamber for the arc-extinguishing melt, reduces the product volume, and simplifies the internal structure of the shell. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 This is a structural diagram showing the relationship between the displacement channel of the first housing and the ignition device and the cutting component.

[0023] Figure 3 This is a schematic diagram of the structure between the second shell, the conductive busbar, and the arc-extinguishing melt.

[0024] Figure label:

[0025] First housing 10, second housing 11, third housing 12, displacement channel 13, limiting groove 14, cutting component 15, limiting protrusion 16, ignition device 17, arc extinguishing medium 18, first conductor 19, signal melt 20, conductive busbar 21, second conductor 22, support leg 23, arc extinguishing melt 24. Detailed Implementation

[0026] The present invention provides a self-excited fuse with improved thermal conductivity, comprising a highly thermally conductive and insulating outer shell, a first conductor, a signal fuse, a conductive busbar, and a second conductor connected in series, an arc-extinguishing fuse, an ignition device, and a cut-off element; the first conductor and the second trigger are respectively disposed within the outer shell as the connection terminals of the self-excited fuse; a displacement channel with one open end and the other closed is provided within the outer shell, the open end of the displacement channel being located at the outer shell wall and communicating with the outside, and the closed end of the displacement channel being located within the outer shell; an arc-extinguishing chamber filled with a thermally conductive arc-extinguishing medium is provided between the displacement channel and the outer shell, and the arc-extinguishing medium is directly in contact with the outer shell. The system consists of a signal melt, an arc-extinguishing melt, and a conductive busbar located within the arc-extinguishing medium, with the conductive busbar passing through a displacement channel. An ignition device is located outside the housing and is fixed to the open end of the displacement channel via a threaded connection. A cutting element is located within the displacement channel between the conductive busbar and the ignition device. The arc-extinguishing melt is connected in parallel to the conductive busbars on both sides of the displacement channel. The signal melt and the ignition device are connected in series in a self-excited triggering circuit. When the signal melt melts, the self-excited triggering circuit is activated, sending a trigger signal to the ignition device. The ignition device then activates, driving the cutting element to move along the displacement channel and cut off the conductive busbar, after which the arc-extinguishing melt melts.

[0027] The following describes preferred embodiments in detail with reference to the accompanying drawings. The directional terms used are for reference only and do not constitute a limitation on the technical solutions of this invention.

[0028] See Figures 1 to 3 The present invention provides a self-excited fuse with improved thermal conductivity, comprising a housing, a first conductor, a signal fuse element, a conductive busbar, and a second conductor connected in series, an arc-extinguishing fuse element, an ignition device, and a cutting element. Wherein:

[0029] The outer shell is made of a highly thermally conductive and high-strength insulating material, such as ceramic or other highly thermally conductive and high-strength insulating materials. In this embodiment, the outer shell includes a first shell 10, a second shell 11, and a third shell 12 that are sequentially assembled. The first shell 10, the second shell 11, and the third shell 12 are fixedly connected by bolts, wherein the second shell 11 has a plate-like structure.

[0030] A displacement channel 13 is provided in the first housing 10 and the second housing 11. The displacement channel 13 is formed by the connection of an elongated hole in the first housing 10 and a groove in the second housing 11. One end of the displacement channel 13 is an open end, and the other end is a closed end. The closed end of the displacement channel 13 is located in the second housing 11, and the open end is located at the shell wall of the first housing 10. The open end of the displacement channel 13 communicates with the outside of the housing. A limiting groove 14 is provided on the inner wall of the displacement channel 13 in the first housing 10. The limiting groove 14 is symmetrically arranged in the displacement channel 13. A cutting element 15 is provided in the displacement channel 13 in the first housing 10, and the cutting element 15 is in close contact with the displacement channel 13. A limiting protrusion 16 is provided on the outer periphery of the cutting element 15 at the position corresponding to the limiting groove 14 of the displacement channel. The limiting protrusion 16 of the cutting element 15 is disposed in the limiting groove 14, thereby defining the initial position of the cutting element 15. To prevent the detached limiting protrusion 16 from obstructing the movement of the cutting member 15 along the displacement channel, the size of the limiting groove 14 is larger than the size of the limiting protrusion 16. When the cutting member 15 and the limiting protrusion 16 are disconnected at the connection point, the limiting protrusion 16 will completely enter the limiting groove 14 under the pressure of the cutting member 15, thereby avoiding obstruction to the movement of the cutting member 15. To facilitate the disconnection of the limiting protrusion 16 from the cutting member 15, the size of the connection between the limiting protrusion 16 and the outer peripheral surface of the cutting member 15 is smaller than the size of the limiting protrusion 16, for example, the thickness and width of the connection are smaller than the size of the limiting protrusion 16.

[0031] An ignition device 17 is disposed outside the first housing 10. The ignition device 17 is fixedly connected to the opening end of the displacement channel 13 within the first housing 10 via a threaded connection. One end of the ignition device 17, which releases high-pressure gas, is located within the displacement channel 13 and corresponds to the cutting element 15. The high-pressure gas released by the ignition device 17 drives the cutting element 15 to overcome the limiting protrusion 16 and move along the displacement channel 13. The threaded connection of the ignition device 17 to the first housing allows for direct removal and replacement after the ignition device reaches its service life, without damaging other parts of the product structure.

[0032] An arc-extinguishing cavity is formed between the first housing 10, the second housing 11, the third housing 12, and the displacement channel 13, and is filled with an arc-extinguishing medium 18. The arc-extinguishing medium 18 is in direct contact with the shell walls of the first housing, the second housing, the third housing, and the displacement channel. The arc-extinguishing medium 18 is made of a highly thermally conductive insulating material, such as quartz sand or alumina powder. By having the highly thermally conductive arc-extinguishing medium directly contact the outer shell, which has good thermal conductivity, the heat dissipation performance of the excitation fuse is improved.

[0033] The first conductor 19, signal fuse 20, conductive bus 21, and second conductor 22 are connected in series, and are located between the mating surfaces of the first housing 10 and the second housing 11. The first conductor 19 and the second conductor 22 are respectively inserted between the mating walls of the first housing 10 and the second housing 11 on opposite sides. One end of each conductor is located outside the housing, serving as the connection end of a self-excited fuse, while the other end is located within the arc-extinguishing medium 18 filled in the first and second housings 10 and 11. The first conductor is fixed to the second and third housings by bolts, and the end of the second conductor connected to the conductive bus is fixed to the second housing by bolts. In this embodiment, the second conductor and the conductive bus are independent parts, fixed together by bolts, or electrically connected by welding. In some embodiments, the second conductor and the conductive bus can also be an integrally formed structure.

[0034] Limiting grooves are provided on opposite sides of the first conductor 19 and the second conductor 22 that contact the shell walls of the first housing 10 and the second housing 11. Correspondingly, limiting protrusions are provided between the contact surfaces of the first housing and the second housing, which are engaged in the limiting grooves of the first conductor and the second conductor to position them and prevent the first conductor 19 and the second conductor 22 from shifting relative to the first housing and the second housing. The limiting grooves on opposite sides of the first conductor and the second conductor have different structural shapes to form a foolproof structure to prevent the first conductor and the second conductor from being installed incorrectly.

[0035] The signal fuse 20 and the conductive bus 21 are located in the arc-extinguishing medium 18 inside the first housing 10 and the second housing 11, respectively. The conductive bus 21 passes through the displacement channel 13, and both ends of the conductive bus 21 are located in the arc-extinguishing medium outside the displacement channel 13. The conductive bus 21 located in the displacement channel 13 is located on the same side as the ignition device 17 and the cut-off member 15, that is, the cut-off member 15 is located between the conductive bus 21 and the ignition device 17. A weak point for reducing mechanical strength is provided on the conductive bus 21 located in the displacement channel 13. In this embodiment, the weak point for breaking is a groove structure, and the cut-off member 15 is provided corresponding to the weak point for breaking. Except for the part of the conductive bus 21 located in the displacement channel 13, the rest of the conductive bus 21 and the signal fuse are embedded in the arc-extinguishing medium 18. Through the heat-conducting arc-extinguishing medium and the housing, the heat conduction and heat dissipation performance of the excitation fuse is improved.

[0036] Several pairs of support legs 23 are respectively provided on the second housing 11 on both sides of the conductive busbar 21. The support legs 23 abut against the two sides of the conductive busbar 21 to position the conductive busbar 21. This prevents the conductive busbar 21 from being damaged by external forces, thus affecting the product's function.

[0037] Arc-extinguishing melts 24 are connected in parallel on opposite sides of the conductive busbar 21. The arc-extinguishing melts 24 are completely contained within the arc-extinguishing medium 18. Both ends of the arc-extinguishing melts 24 are electrically connected to the conductive busbars on opposite outer sides of the displacement channel 13, forming a parallel connection between the arc-extinguishing melts 24 and the portion of the conductive busbar 21 located in the displacement channel 13. Since the conductive busbars are fixed to the housing by bolts, to avoid contact between the arc-extinguishing melts and the bolts, the arc-extinguishing melts 24 are designed as a curved, three-dimensional structure away from the conductive busbars, creating clearance space. Several narrow necks are provided on the arc-extinguishing melts 24, and mounting holes are provided at these necks. These mounting holes fit onto the support legs 23, positioning the arc-extinguishing melts 24. The arc-extinguishing melts 24 are positioned across the closed end of the displacement channel 13.

[0038] The self-excited trigger circuit (not shown) is electrically connected to the first conductor 19 and the busbar 21 at both ends of the signal fuse 21 via wires, so that the signal fuse 21 is connected in series in the self-excited trigger circuit. The signal receiver of the ignition device is also connected in series in the self-excited trigger circuit. In the initial state and normal current-carrying state, the self-excited trigger circuit is not conductive. For example, a control element that controls whether the circuit is conductive by voltage can be connected in series in the self-excited trigger circuit to control whether the self-excited trigger circuit is conductive. Of course, whether the self-excited trigger circuit is conductive can also be achieved in other ways.

[0039] The self-excited trigger circuit is mounted on a circuit board, which is located outside the housing and recessed into the casing. When a fault current occurs, the signal fuse 21 melts. The melting of the signal fuse 21 generates an arc, causing a momentary voltage increase at the break point of the signal fuse 21. This momentary voltage increase causes the control element connected in series in the self-excited trigger circuit to conduct, thus activating the self-excited trigger circuit. The increased voltage at the melt point of the signal fuse 21 then acts as a trigger signal for the ignition device 17 through the activated self-excited trigger circuit, causing the temperature of the ignition device 17 to rise, igniting the propellant and releasing high-pressure gas as the driving force.

[0040] Working principle:

[0041] During normal current flow, the current flows through the circuit formed by the first conductor, the signal fuse, the busbar, and the second conductor connected in series. Since the resistance of the arc-extinguishing fuse connected in parallel to the busbar is much greater than the resistance of the busbar, the current flowing through the arc-extinguishing fuse is very small and can be ignored. During normal current flow, the self-excited triggering circuit is not conductive.

[0042] When a fault current is generated and flows through the circuit, such as a short-circuit current, the signal fuse 19 melts, triggering the self-excitation trigger circuit to conduct, thereby triggering the ignition device 17 to act, releasing high-pressure gas in the displacement channel 13, driving the cut-off element 15 to overcome the limitation of the limiting protrusion 16 and move along the displacement channel, cutting off the conductive busbar 21 from the weak point of disconnection, and the arc-extinguishing fuse 24 melts.

[0043] Arc extinguishing principle:

[0044] At the instant the conductive busbar 21 is disconnected, its resistance is much greater than that of the arc-extinguishing melt 24. Most of the current on it is transferred to the arc-extinguishing melt 24. Therefore, the current flowing through the conductive busbar 21 when it is disconnected is very small. As a result, the arc generated at the break point after the conductive busbar is disconnected is very small and can be easily extinguished by air. The arc-extinguishing melt 24 has a relatively large resistance, which limits the current flowing through it. Moreover, multiple arc-extinguishing melts 24 can achieve current diversion, further reducing the current. Therefore, when the arc-extinguishing melt 24 melts, the arc generated at the break point is also correspondingly smaller and can be quickly extinguished by the arc-extinguishing medium.

[0045] Thermal conductivity and heat dissipation function: Since the signal fuse, conductive busbar, and arc-extinguishing fuse are placed in the arc-extinguishing medium, and one end of the first conductor and the second conductor are placed in the arc-extinguishing medium and the other end is placed in the air outside the housing, while the rest are in contact with the first housing and the second housing, the thermally conductive arc-extinguishing medium is in direct contact with the thermally conductive housing. The heat generated by the signal fuse, conductive busbar, and arc-extinguishing fuse is conducted to the housing through the highly thermally conductive arc-extinguishing medium, and then dissipated to the air outside the housing through the highly thermally conductive housing. This improves the thermal conductivity and heat dissipation function of the self-excited fuse, reduces the overall temperature of the product, and thus reduces the power consumption of the product.

[0046] The structure of the above embodiments is not intended to limit the structure of the present invention. As long as the housing is made of a high thermal conductivity, high strength and insulating material, the arc extinguishing medium is made of a high thermal conductivity insulating material, the arc extinguishing medium is in direct contact with the housing, the signal melt, the conductive bus and the arc extinguishing melt are disposed in the arc extinguishing medium, a displacement channel is provided in the housing, the conductive bus is partially disposed in the displacement channel, a cutting element capable of cutting off the conductive bus is provided in the displacement channel, and the ignition device is provided with a threaded connection between the outside of the housing and the open end of the displacement channel, the specific structure of the product can be designed according to actual needs.

Claims

1. A self-energizing fuse with improved heat conduction performance, characterized by The self-energizing fuse comprises a high-thermal-conductivity, high-strength and insulating shell, a first conductor, a signal fuse, a conductive row and a second conductor connected in series, an arc-extinguishing fuse, an ignition device and a cutting member; the first conductor and the second conductor are arranged in the shell as connection ends of the self-energizing fuse; An open-end displacement channel is arranged in the shell, and the open end of the displacement channel is in communication with the outside at the shell wall of the shell, and the closed end of the displacement channel is in the shell; An arc-extinguishing chamber filled with arc-extinguishing medium is arranged between the displacement channel and the shell, the arc-extinguishing medium is in direct contact with the shell, the signal fuse, the arc-extinguishing fuse and the conductive row are arranged in the arc-extinguishing medium, and the conductive row passes through the displacement channel; The ignition device is arranged outside the shell and is fixed at the open end of the displacement channel by screw connection, the cutting member is arranged in the displacement channel between the conductive row and the ignition device, the arc-extinguishing fuse is connected in parallel on the conductive row on both sides of the displacement channel, the conductive loop in which the signal fuse is arranged is in conductive connection with the trigger signal receiving end of the ignition device to form a self-energizing trigger loop, when the signal fuse is conductive, the self-energizing trigger loop is not conductive, when the signal fuse is fused, the self-energizing trigger loop is conductive, a trigger signal is sent to the ignition device, the ignition device is actuated to drive the cutting member to displace along the displacement channel to cut off the conductive row, and then the arc-extinguishing fuse is fused.

2. The self-energizing fuse of claim 1, wherein, The arc-extinguishing fuse is in a curved structure curved away from the conductive row.

3. The self-energizing fuse of claim 2, wherein, The arc-extinguishing fuse is arranged across the closed end of the displacement channel.

4. The self-energizing fuse of claim 1, wherein, The conductive row is provided with a breaking weak part, the breaking weak part is arranged in the displacement channel, and the cutting member is arranged correspondingly to the breaking weak part.

5. Self-energizing fuse according to any of claims 1 to 4, characterized in that The shell comprises a first shell, a second shell and a third shell connected in sequence, the displacement channel is arranged in the first shell and the second shell, the open end of the displacement channel is arranged at the shell wall of the first shell, and the closed end of the displacement channel is arranged in the second shell; The first conductor, the second conductor and the conductive row are arranged between the first shell and the second shell, and the first shell, the second shell and the third shell form the arc-extinguishing chamber.

6. The self-energizing fuse of claim 5, wherein, A plurality of supporting legs are arranged in the second shell on opposite sides of the conductive row and extend towards the conductive row correspondingly, and the supporting legs abut against the opposite sides of the conductive row.

7. The self-energizing fuse of claim 6, wherein, An installation hole is arranged at the narrow neck of the arc-extinguishing fuse, and the installation hole is arranged on the supporting leg.

8. The self-energizing fuse of claim 1, wherein, A limiting groove is arranged on the inner wall of the displacement channel, a limiting protrusion is arranged on the outer periphery of the cutting member correspondingly to the limiting groove, and the limiting protrusion of the cutting member is clamped in the limiting groove in the displacement channel.

9. The self-energizing fuse of claim 8, wherein, A gap is arranged between the limiting groove and the limiting protrusion.

10. The self-energizing fuse of claim 5, wherein, The second conductor and the conductive row are conductively connected by a bolt, or the second conductor and the conductive row are integrally formed.

11. The self-energizing fuse of claim 5, wherein, The first shell, the second shell and the third shell are fixed by bolt connection, the first conductor is fixed with the second shell and the third shell by thread connection, and one end of the second conductor connected with the conductive row is fixed with the second shell by bolt connection.

Images