A fuse capable of withstanding lightning current pulse current

Abstract

The present invention discloses a fuse capable of withstanding lightning current pulse current, which is used to connect an SPD in series as an external overcurrent protection device, and includes an insulating tube and a fuse arranged on the insulating tube to form an integrated structure, wherein the fuse is connected to electrodes arranged at both ends of the insulating tube to form a passage; the insulating tube forms a closed space filled with inert gas inside through the electrodes at both ends, and the two electrodes form a discharge gap in the closed space. The present invention forms an integrated external protection device by combining the discharge gap filled with inert gas with the fuse structure, which can be combined with the SPD to form a comprehensive surge protection system, which has a small size and a high degree of integration, and has a good breaking effect, and has a strong protection against the influence of lightning pulse current, and can prevent false disconnection easily when the lightning current passes through.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic components, and in particular relates to a fuse capable of withstanding lightning current pulse current. Background Art

[0002] Lightning disasters are one of the most serious natural disasters. Every year, countless casualties and property losses are caused by lightning disasters around the world. With the extensive application of electronic and microelectronic integrated equipment, the damage to systems and equipment caused by lightning overvoltage and lightning electromagnetic pulses is increasing. Therefore, it is very important to solve the problem of lightning disaster protection for buildings and electronic information systems as soon as possible.

[0003] As the requirements for lightning protection of related equipment become increasingly stringent, installing surge protectors to suppress surges and transient overvoltages on the lines and discharge overcurrents on the lines has become one of the important links in modern lightning protection technology. SPD surge protectors, also called lightning arresters, are electronic devices that provide safety protection for various electronic equipment, instruments, and communication lines. When a spike current or voltage suddenly occurs in an electrical circuit or communication line due to external interference, the surge protector can conduct and shunt in a very short time, thereby preventing the surge from damaging other equipment in the circuit.

[0004] SPD is often set in the circuit to form a comprehensive protection system with other functional components, especially in many low-voltage power systems. In order to prevent a series of impact currents such as pulse current and lightning current from damaging the load equipment, many functional components are set in the protection system, including fuses, sub-resistors, inductors, gas discharge tubes, etc. connected externally. In order to improve stability, most of the existing technologies use a variety of protection devices in parallel to achieve a comprehensive protection effect. For example, SPD is connected in series with a fuse and a gas discharge tube at the same time. When the main current exceeds the specified value, the fuse will melt itself to protect the circuit, or when a lightning current occurs, the fuse is prone to mis-breaking. The lightning current can be conducted through the provided gas discharge tube to achieve the effect of current discharge. However, most of the existing structures use the method of independent component setting, which results in a large volume of the external part structure, which is not convenient to set. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a fuse capable of withstanding lightning current pulse current.

[0006] The technical solution adopted by the present invention is:

[0007] A fuse capable of withstanding lightning current pulse current, used for connecting in series with an SPD as an external overcurrent protection device, comprising an insulating tube and a fuse arranged on the insulating tube to form an integrated structure, wherein the fuse is connected to electrodes arranged at both ends of the insulating tube to form a path;

[0008] The insulating tube forms a closed space filled with an inert gas inside through electrodes at both ends, and the two electrodes form a discharge gap in the closed space.

[0009] The present invention is an integrated circuit protection device, including two functional components, wherein a discharge gap structure with an inert gas enclosed space is used as the main structure, and a fuse is provided on the structure. The discharge gap is formed by an electrode structure with a certain distance between the two ends and an inert gas system in the middle. The electrodes at the two ends are used to connect an external circuit. When the voltage applied between the two electrodes is insufficient to break through the inert gas to generate an arc, the discharge gap is open. The fuse simultaneously connects the two electrodes to form a path, which is equivalent to an equivalent circuit formed by connecting the discharge gap and the fuse in parallel.

[0010] That is to say, the electrodes at both ends are connected to the external circuit. When the current flows in the normal state, the voltage is too small to break down and discharge, so the current flows through the fuse. Once the current fluctuates and the current exceeds the threshold, although the voltage value still cannot reach the breakdown voltage, when the current passes through the fuse, the fuse heats up and melts due to the excessive current, thus protecting the circuit.

[0011] When a lightning current is connected, a certain voltage is applied between the two poles of the gas gap, and an uneven electric field is generated between the poles: under the action of this electric field, the gas in the tube begins to be freed. When the applied voltage increases to make the field strength between the poles exceed the insulation strength of the gas, the gap between the two poles will be discharged and broken down, and the original insulating state will be converted into a conductive state. After conduction, the voltage between the two poles of the discharge gap is maintained at the residual voltage level determined by the discharge arc. This residual voltage is generally very low, so that the electronic equipment connected in parallel with the discharge tube is protected from damage by overvoltage. In other words, when the lightning pulse current reaches, a path is formed between the discharge gap, and the lightning current passes through the discharge gap, which will not cause the fuse to break by mistake. Compared with the prior art, the integrated structure of the present invention not only occupies less space, but also facilitates flexible arrangement, and the fuse will not be broken by mistake due to the passage of lightning current.

[0012] Furthermore, the fuse is wound around the axis of the insulating tube for multiple turns to form an electromagnetic induction coil.

[0013] The present invention uses a single fuse to connect the two electrodes at both ends, but in order to improve the breaking performance, it is wound into a spiral structure to form an electromagnetic induction coil. Specifically, the induction coil is composed of a wire wound around an insulating tube in a circle, the wires are insulated from each other, and the insulating tube can be hollow or contain an iron core or a magnetic powder core.

[0014] An inductor is a device that works on the principle of electromagnetic induction. When current flows through a wire, a certain electromagnetic field will be generated around the wire, and the wire of the electromagnetic field will induce the wires within the electromagnetic field. The electrical characteristics of an inductor are opposite to those of a capacitor, "passing low frequencies and blocking high frequencies".

[0015] Generally speaking, resistors, capacitors and inductors all present a certain resistance to the flow of electrical signals in the circuit, and this resistance is called "impedance". The impedance presented by the inductor coil to the current signal utilizes the self-inductance of the coil. In the present invention, the fuse wire is wound to form an inductor coil structure, which can not only fuse the protection circuit when the current exceeding the carrying limit passes through, but also generate a larger impedance when the high-frequency current passes through, cooperating with the discharge gap to discharge the current.

[0016] Furthermore, the fuse is wound around the inner and outer wall surfaces of the insulating tube.

[0017] The hollow-core inductor structure formed by the fuse is fixed by attaching the surface to the surface of the insulating tube, but it can be wound around the inner and outer wall surfaces of the insulating tube according to actual needs. If it is set inside the inner wall, the integrity is further improved, and it is suitable for systems that need to hide the energized coil in the insulating tube under some special environments. Wrapping it outside the insulating tube is not only easy to assemble and has a lower manufacturing cost, but also makes it easy to adjust the number of coil turns and the coil radius.

[0018] Furthermore, the fuse is arranged in the insulating tube layer.

[0019] Compared with the method of setting it on the inner and outer surfaces, it is also possible to wrap the fuse around the coil and embed it in the insulating tube during manufacturing. The electromagnetic induction coil set in this way is more stable and will not be affected by the internal and external environment. It also provides support for subsequent functions. This method is suitable for casting insulating tubes made of high-temperature resistant plastic materials. The prepared fuse coil is fixed in the mold by using a mold for casting.

[0020] Furthermore, at least one resistance wire attached to the surface of the insulating tube is connected in series between the fuse wires. The resistance wire is energized to generate heat and the heat is transferred to the insulating tube. When the temperature of the insulating tube reaches a threshold, an opening connecting to the outside appears in the enclosed space inside the insulating tube, causing the internal inert gas to leak and fail, and the fuse wire melts.

[0021] In the existing comprehensive surge protection system, most of them adopt an air discharge tube structure, which is the same as the discharge gap used in the present invention, and is used to prevent the lightning current from affecting other protection components and load circuits.

[0022] The discharge principle is that the inert gas filled between the two electrodes can begin to be ionized and become conductive under a high-voltage electric field, thereby changing from high resistance to low resistance to conduct lightning current. In other words, the insulation strength of the entire internal inert gas system determines the discharge effect because it has a lower breakdown voltage. However, because the present invention is an integrated surge protection device, the fuse structure needs to be changed after the device is blown to completely form a short circuit, so the original advantage of the low breakdown voltage of the inert gas is transformed into a disadvantage. Although the fuse is completely short-circuited after it is blown, it does not affect the discharge gap. Once the voltage applied to both ends is higher than the breakdown voltage, a path will still be formed. This phenomenon causes the components that were originally determined by the system to be short-circuited to cause the electrical equipment or protection system to catch fire after the current passes through them. This phenomenon is a common technical problem in existing integrated surge protectors.

[0023] Therefore, in order to solve the technical problem, the present invention connects one or more heat-generating structures in series on the fuse. The structure has a certain resistance value. When current passes through, the material continuously generates heat. The heat is transferred to the insulating tube, causing cracks to appear at specific positions of the insulating tube, causing the internal inert gas to leak and mix with the air. The breakdown voltage of air is relatively high, causing the insulating tube to fail, thereby completely forming a short circuit and avoiding the occurrence of continuous current.

[0024] Among them, the fuse is also a resistance wire structure, but the melting point and material of the separately set resistance wire are different from those of the fuse. For example, a single resistance wire structure is set, which uses a material with a high melting point and high heat generation. When current passes through the fuse and the resistance wire, both the fuse and the resistance wire will generate heat. However, since the heat generated by the resistance wire and the fuse when the normal working current passes through is not enough to make the fuse melt, and no cracks will appear in specific parts of the insulating tube. Only when the heat generation reaches the melting temperature of the fuse, the insulating tube will also crack in its specific parts due to the increase in temperature, so that the fuse melts and the cracks in the insulating tube appear simultaneously.

[0025] In the above case, because a resistance wire structure with higher heat generation is used, when an abnormal current passes through, the heat generated by the fuse itself does not reach the melting temperature, but the temperature transmitted by the resistance wire causes the temperature of the fuse to rise and melt. Generally, the melting position is at the connection between the resistance wire and the fuse. Because the melting of the fuse and the cracking of the insulation tube need to be carried out simultaneously, the heat is transmitted by the resistance wire, which is convenient for adjustment and setting to occur simultaneously.

[0026] Furthermore, the surface of the insulating tube is provided with at least one thin-wall structure corresponding to the resistance wire.

[0027] Furthermore, the thin-wall structure is a groove.

[0028] Furthermore, an insulating hot melt colloid is provided on the connection surface between the insulating tube and the electrode for sealing, and when the temperature of the insulating tube reaches a threshold, the insulating hot melt colloid melts to form a gap.

[0029] Furthermore, the insulating tube is provided with at least one opening and an insulating hot melt adhesive is provided on the opening for sealing. When the temperature of the insulating tube reaches a threshold, the insulating hot melt adhesive melts and a gap is formed.

[0030] Furthermore, a magnetic conductor is also provided in the insulating tube. By providing a magnetic conductor structure in the insulating tube and an external fuse structure to form a magnetic core inductance, magnetic saturation can be more easily generated. The magnetic conductor is directly placed in the insulating tube, but its material is an insulating material, and its length is less than the distance between the electrodes at both ends, so as to avoid affecting the discharge gap structure.

[0031] The beneficial effects of the present invention are:

[0032] (1) The present invention forms an integrated external protection device by combining a discharge gap filled with an inert gas with a fuse structure, which can be combined with an SPD to form a comprehensive surge protection system. The system has a small size and a high degree of integration, and has a good breaking effect and a strong protection against the influence of lightning pulse current, and can prevent false breaking easily when lightning current passes through.

[0033] (2) The present invention winds the fuse into a coil shape, so that it has a lower resistance when a low-voltage DC working current passes through it, but when a high-frequency pulse current passes through it, a larger combined and induced voltage is generated, thereby cooperating with the breakdown discharge between the two electrodes in the insulating tube, further increasing the breaking effect;

[0034] (3) The present invention is provided with a resistance wire structure that generates heat when powered on. When the heating temperature reaches the melting temperature of the fuse, the temperature rise of the insulating tube reaches a threshold value and surface cracks are generated. When the fuse melts, the inert gas system inside the insulating tube is simultaneously destroyed. The air enters through the gap and increases the breakdown voltage, causing complete failure and short circuit, thereby avoiding the situation where the device still has a continuous current after the fuse melts. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is an axonometric diagram of a fuse in Embodiment 2 of the present invention;

[0036] Figure 2 is a front view of the fuse in Embodiment 2 of the present invention;

[0037] Figure 3 It is a schematic diagram of the disassembled structure of the entire fuse of the present invention.

[0038] In the figure: 1-electrode, 2-fuse wire, 3-insulating tube, 4-resistance wire, 5-groove. DETAILED DESCRIPTION

[0039] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments.

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0042] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0043] In the description of this application, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, if the terms "first", "second", etc. appear in the description of this application, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0044] In addition, if the terms "horizontal" or "vertical" appear in the description of this application, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0045] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] Embodiment 1:

[0047] This embodiment is a fuse that can withstand lightning current impact, such as Figure 1-3 As shown, it mainly includes a cylindrical insulating tube 3 structure, and an electrode 1 structure for sealing is provided at two openings of the insulating tube 3. The electrode 1 is provided with a convex part that is recessed inward, and the convex part penetrates into the opening of the insulating tube 3, and is bonded to the annular flange surface of the insulating tube 3 and the electrode 1, and an insulating glue for bonding is provided at the bonding gap.

[0048] As can be seen in the figure, when two symmetrically arranged electrodes 1 are fixed on the opening of the insulating tube 3 , there is still a certain distance between the two protruding parts inside thereof, thereby forming a discharge gap with the inert gas filled inside the insulating tube 3 .

[0049] In this embodiment, a fuse 2 is provided on the outer wall of the insulating tube 3, and the fuse 2 is connected in series with the electrodes 1 on both sides, so as to form a separate power-on circuit. When the two ends of the fuse are connected to the protection circuit, when the normal working current passes through, the current directly passes through the fuse 2. At this time, the temperature of the fuse 2 is much lower than the fusing temperature, and the circuit operates normally.

[0050] Once the lightning current is applied to both ends of the electrode 1, the voltage value is higher than the breakdown voltage of the inert gas in the insulating tube 3, so that the discharge gap between the electrodes 1 forms a path with extremely low resistance, and the lightning current passes directly through the discharge gap, which will not cause the fuse 2 to break incorrectly, and at the same time facilitate the subsequent equipment to operate and discharge current.

[0051] Once the current voltage applied to both ends of electrode 1 is lower than the breakdown voltage of the inert gas, but it passes through fuse 2 and causes it to heat up, and when the temperature continues to rise and exceeds the melting temperature, fuse 2 melts to form an open circuit, thereby achieving the effect of protecting the load circuit.

[0052] Embodiment 2:

[0053] This embodiment is a fuse capable of withstanding lightning current impact, comprising a cylindrical insulating tube 3 structure, and an electrode 1 structure for sealing is provided at two openings of the insulating tube 3. The electrode 1 is provided with an inwardly recessed convex portion, which penetrates into the opening of the insulating tube 3 and fits the insulating tube 3 with the annular flange surface of the electrode 1, and an insulating glue for bonding is provided at the fitting gap.

[0054] When two symmetrically arranged electrodes 1 are fixed on the opening of the insulating tube 3 , there is still a certain distance between the two protruding parts inside thereof, thereby forming a discharge gap with the inert gas filled in the insulating tube 3 .

[0055] Among them, Figure 3 As shown, a conductive wire structure is provided on the outer wall of the insulating tube 3, and the conductive wire is connected in series with the electrodes 1 on both sides, so as to form a separate power-on circuit. When the two ends of the conductive wire are connected to the protection circuit, when the normal working current passes through, the current directly passes through the fuse 2. At this time, the temperature of the conductive wire is much lower than the fusing temperature, and the circuit operates normally.

[0056] The conductive wire includes two parts connected in series to form a whole conductive wire, which are divided into a fuse wire 2 and a resistance wire 4 according to their functions. Both the fuse wire 2 and the resistance wire 4 are wire structures, but they are welded with different materials and thickness specifications to form a single conductive wire material. The melting point of the fuse wire 2 is relatively low, while the melting point of the resistance wire 4 is relatively high, and the temperature of the resistance wire 4 rises rapidly when the current passes through it.

[0057] The conductive wire structure is spirally wound on the outer surface of the insulating tube 3 to form an inductor coil structure.

[0058] A spiral groove 5 is provided on the outer wall of the insulating tube 3, and the resistance wire 4 is arranged in the groove 5 and fits with the inner wall of the groove 5, thereby increasing the contact area between the resistance wire 4 and the wall of the insulating tube 3 and improving the heat transfer efficiency.

[0059] The specific product needs to be selected according to the use environment and technical indicators. The materials of the fuse 2, the resistance wire 4 and the insulating tube 3 are selected so that when the abnormal current passes through the entire fuse, the temperature of the resistance wire 4 rises rapidly and is transmitted to the insulating tube 3 and the fuse 2 at the same time. The adhesive provided on the gap between the insulating tube 3 and the electrode 1 will produce a gap after being heated, causing the inert gas inside to overflow. At the same time, when the temperature of the fuse 2 rises to the melting temperature, the contact position between the fuse 2 and the resistance wire 4 is melted.

[0060] That is to say, once the abnormal current passes through and causes the fuse 2 to melt, cracks will be generated in the sealing structure formed by the insulating tube 3 and the electrode 1 at the same time, so that the internal inert gas system will be broken. Then, when the fuse 2 melts, the discharge gap will also fail to form a short circuit, thereby avoiding the existence of a continuous current.

[0061] Embodiment 3:

[0062] This embodiment is a fuse capable of withstanding lightning current impact, including a cylindrical insulating tube 3 structure, and electrodes 1 structures for sealing are provided on two openings of the insulating tube 3 .

[0063] The electrode 1 is provided with an inwardly recessed convex portion, which penetrates into the opening of the insulating tube 3 and fits with the annular flange surface of the insulating tube 3 and the electrode 1, and an insulating glue for bonding is provided at the fitting gap.

[0064] When two symmetrically arranged electrodes 1 are fixed on the opening of the insulating tube 3 , there is still a certain distance between the two protruding parts inside thereof, thereby forming a discharge gap with the inert gas filled in the insulating tube 3 .

[0065] A conductive wire structure is provided on the inner wall of the insulating tube 3 , and the conductive wire is connected in series with the electrodes 1 on both sides, thereby forming a separate current-carrying circuit.

[0066] The conductive wire structure is spirally wound inside the insulating tube 3 to form an inductor coil structure.

[0067] The two ends of the conductive wire are connected to the protection circuit. When the normal working current passes through, the current passes directly from the fuse wire 2. At this time, the temperature of the conductive wire is much lower than the melting temperature, and the circuit operates normally. The conductive wire includes two parts connected in series to form a whole conductive wire, which are divided into a fuse wire 2 and a resistance wire 4 according to their functions. Both the fuse wire 2 and the resistance wire 4 are wire structures, but they are welded with different materials and thickness specifications to form a single conductive wire material. Among them, the melting point of the fuse wire 2 is low, while the melting point of the resistance wire 4 is high, and the temperature of the resistance wire 4 rises faster when the current passes through.

[0068] A spiral groove 5 is provided on the inner wall of the insulating tube 3, and the resistance wire 4 is arranged in the groove 5 and fits with the inner wall of the groove 5, thereby increasing the contact area between the resistance wire 4 and the wall of the insulating tube 3 and improving the heat transfer efficiency.

[0069] Similar to the above-mentioned embodiment 2, the heat is transferred to the insulating tube 3 and the fuse 2 at the same time through the heat-generating resistance wire 4 structure, so that the discharge gap in the insulating tube 3 is simultaneously invalidated when the fuse 2 is blown. Compared with the above-mentioned embodiment 2, this embodiment adopts a more integrated structural design, where the conductive wire is arranged inside the insulating tube 3, and the outside is a homogeneous insulating tube 3 structure.

[0070] Embodiment 4:

[0071] This embodiment is a fuse that can withstand lightning current impact, and also includes a cylindrical insulating tube 3 structure, and an electrode 1 structure for sealing is provided on the two openings of the insulating tube 3. The electrode 1 is provided with a convex part that is recessed inward, and the convex part penetrates into the opening of the insulating tube 3, and is fitted on the annular flange surface of the insulating tube 3 and the electrode 1, and an adhesive insulating glue is provided at the fitting gap. When the two symmetrically arranged electrodes 1 are fixed on the opening of the insulating tube 3, there is still a certain distance between the two convex parts inside, so as to form a discharge gap with the inert gas filled in the insulating tube 3. A conductive wire structure is provided on the insulating tube 3, and the conductive wire is connected in series with the electrodes 1 on both sides, so as to form a separate power-on circuit. The two ends of the conductive wire are connected to the protection circuit. When the normal working current passes, the current passes directly from the fuse 2. At this time, the temperature of the conductive wire is much lower than the fusing temperature, and the circuit operates normally.

[0072] The conductive wire includes two parts connected in series to form a whole conductive wire, which are divided into a fuse wire 2 and a resistor wire 4 according to their functions. Both the fuse wire 2 and the resistor wire 4 are wire structures, but they are welded with different materials and thickness specifications to form a single conductive wire material. The melting point of the fuse wire 2 is lower, while the melting point of the resistor wire 4 is higher, and the temperature of the resistor wire 4 rises faster when the current passes through it.

[0073] Different from the above two embodiments, the conductive wire structure in this embodiment is a spirally wound inductor coil structure, but the inductor coil structure is arranged inside the insulating tube 3, that is, it is not connected to the internal inert gas and the external space at the same time, that is, it is wrapped with the insulating tube 3 material to form an integrated structure.

[0074] This structural design does not require the groove 5 structure, because the entire resistance wire 4 is wrapped by the insulating tube 3, and its contact area is large, so the heat conduction effect is better. At this time, the resistance wire 4 also transfers heat to the insulating tube 3 and the fuse 2 at the same time, and the length ratio of the resistance wire 4 to the fuse 2 can be adjusted to meet different usage requirements.

[0075] The materials of the fuse 2, the resistance wire 4 and the insulating tube 3 can be selected according to the actual technical requirements, so that when the abnormal current passes through the entire fuse, the temperature of the resistance wire 4 rises rapidly and is transmitted to the insulating tube 3 and the fuse 2 at the same time, and the adhesive provided on the gap between the insulating tube 3 and the electrode 1 will produce a gap after being heated, causing the inert gas inside to overflow. At the same time, after the temperature of the fuse 2 rises to the melting temperature, the contact position between the fuse 2 and the resistance wire 4 is melted. Once the abnormal current passes and causes the fuse 2 to melt, the sealing structure formed by the insulating tube 3 and the electrode 1 will also produce cracks, so that the internal inert gas system is broken. When the fuse 2 melts, the discharge gap also fails to form a circuit break, thereby avoiding the situation of continuous current.

[0076] Embodiment 5:

[0077] This embodiment is a fuse capable of withstanding lightning current impact, and also includes a cylindrical insulating tube 3 structure, and an electrode 1 structure for sealing is provided at two openings of the insulating tube 3. The electrode 1 is provided with an inwardly recessed convex portion, which penetrates into the opening of the insulating tube 3 and fits the insulating tube 3 with the annular flange surface of the electrode 1, and an insulating glue for bonding is provided at the fitting gap.

[0078] When two symmetrically arranged electrodes 1 are fixed on the opening of the insulating tube 3, there is still a certain distance between the two protruding parts inside, thereby forming a discharge gap with the inert gas filled inside the insulating tube 3. A conductive wire structure is provided on the insulating tube 3, and the conductive wire is connected in series with the electrodes 1 on both sides, thereby forming a separate power-on circuit. When the two ends of the conductive wire are connected to the protection circuit, when the normal working current passes through, the current passes directly from the fuse 2. At this time, the temperature of the conductive wire is much lower than the fusing temperature, and the circuit operates normally.

[0079] The conductive wire includes two parts connected in series to form a whole conductive wire, which are divided into a fuse wire 2 and a resistor wire 4 according to their functions. Both the fuse wire 2 and the resistor wire 4 are wire structures, but they are welded with different materials and thickness specifications to form a single conductive wire material. The melting point of the fuse wire 2 is lower, while the melting point of the resistor wire 4 is higher, and the temperature of the resistor wire 4 rises faster when the current passes through it.

[0080] Among them, the fuse wire 2 and the resistance wire 4 are both arranged on the outer wall of the insulating tube 3, and the conductive wire includes at least two resistance wires 4 arranged at intervals, and the resistance wire 4 is arranged at a position close to the electrodes 1 at both ends, and a groove 5 with a spiral structure for accommodating the resistance wire 4 is provided in the region. The resistance wire 4 is arranged at a position close to the electrode 1 to facilitate the heat of the resistance wire 4 to be quickly transferred to the insulating glue between the insulating tube 3 and the electrode 1, so that when the resistance wire 4 heats up, it can ensure that cracks are generated in the insulating glue while the fuse wire 2 is melted.

[0081] Embodiment 6:

[0082] This embodiment is a fuse that can withstand lightning current impact, and also includes a cylindrical insulating tube 3 structure, and an electrode 1 structure for sealing is provided on the two openings of the insulating tube 3. The electrode 1 is provided with a convex part that is recessed inward, and the convex part penetrates into the opening of the insulating tube 3, and is fitted on the annular flange surface of the insulating tube 3 and the electrode 1, and an adhesive insulating glue is provided at the fitting gap. When the two symmetrically arranged electrodes 1 are fixed on the opening of the insulating tube 3, there is still a certain distance between the two convex parts inside, so as to form a discharge gap with the inert gas filled in the insulating tube 3. A conductive wire structure is provided on the insulating tube 3, and the conductive wire is connected in series with the electrodes 1 on both sides, so as to form a separate power-on circuit. The two ends of the conductive wire are connected to the protection circuit. When the normal working current passes, the current passes directly from the fuse 2. At this time, the temperature of the conductive wire is much lower than the fusing temperature, and the circuit operates normally.

[0083] The conductive wire includes two parts connected in series to form a whole conductive wire, which are divided into a fuse wire 2 and a resistance wire 4 according to their functions. Both the fuse wire 2 and the resistance wire 4 are wire structures, but they are welded with different materials and thickness specifications to form a single conductive wire material. Among them, the melting point of the fuse wire 2 is low, while the melting point of the resistance wire 4 is high, and the temperature rise of the resistance wire 4 is fast when the current passes through. Among them, the fuse wire 2 and the resistance wire 4 are both arranged on the outer wall of the insulating tube 3, and the conductive wire includes at least two resistance wires 4 arranged at intervals. A plurality of openings are provided on the outer side of the wall of the insulating tube 3, and insulating glue is provided on the openings for sealing. Under normal conditions, the entire insulating tube 3 is in a completely sealed state. Once the resistance wire 4 heats up, the temperature of the insulating tube 3 rises, causing the insulating glue on the plurality of openings to melt and produce cracks. Compared with the scheme in the above-mentioned embodiment, a plurality of openings are evenly arranged on the insulating tube 3, which can quickly generate heat after receiving a certain amount of heat, so as to facilitate the adjustment of the specifications and materials between the fuse wire 2 and the resistance wire 4, and a better synchronization effect has been achieved.

[0084] The present invention is not limited to the above optional implementations, and anyone can derive other various forms of products under the enlightenment of the present invention. The above specific implementations should not be understood as limiting the scope of protection of the present invention. The scope of protection of the present invention should be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. A fuse capable of withstanding lightning current pulse current, used in series with an SPD as an external overcurrent protection device, characterized in that: It comprises an insulating tube (3) and a fuse (2) arranged on the insulating tube (3) to form an integrated structure, wherein the fuse (2) is connected to electrodes (1) arranged at both ends of the insulating tube (3) to form a passage; The insulating tube (3) forms a closed space filled with an inert gas inside through the electrodes (1) at both ends, and the two electrodes (1) form a discharge gap in the closed space; The fuse (2) is wound around the axis of the insulating tube (3) for multiple turns to form an electromagnetic induction coil; The fuse (2) is wound around the inner and outer wall surfaces of the insulating tube (3); Alternatively, the fuse (2) is arranged in a tube layer of the insulating tube (3); At least one resistance wire (4) attached to the surface of the insulating tube (3) is connected in series between the fuse wires (2). The resistance wire (4) generates heat when energized and transmits the heat to the insulating tube (3). When the temperature of the insulating tube (3) reaches a threshold, an opening connecting the sealed space inside the insulating tube (3) appears, which causes the internal inert gas to leak out and become ineffective. At the same time, the fuse wire (2) melts. An insulating hot melt colloid is provided on the connection surface between the insulating tube (3) and the electrode (1) for sealing, and when the temperature of the insulating tube (3) reaches a threshold value, the insulating hot melt colloid melts to form a gap; Or the insulating tube (3) is provided with at least one opening and an insulating hot melt adhesive is provided on the opening for sealing, and when the temperature of the insulating tube (3) reaches a threshold value, the insulating hot melt adhesive melts to form a gap; A magnetic conductor is also provided in the insulating tube (3).

2. A fuse capable of withstanding lightning current pulse current according to claim 1, characterized in that: The surface of the insulating tube (3) is provided with at least one thin-wall structure corresponding to the resistance wire (4).

3. A fuse capable of withstanding lightning current pulse current according to claim 2, characterized in that: The thin-wall structure is a groove (5).

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