Conductive gasket applied to lightning impulse resistance of maintenance cover plate of aircraft fuel tank covering cap

Abstract

The utility model relates to the technical field of composite materials, in particular to a conductive gasket applied to lightning impulse resistance of a maintenance cover plate of a fuel tank opening cover of an airplane, which comprises aluminum alloy braid layers and connecting pieces fixedly arranged on the aluminum alloy braid layers, and the aluminum alloy braid layers are connected end to end through the connecting pieces and are in an annular shape. The aluminum alloy braided layer is provided with a plurality of vertically-through mounting through holes, and meshes of the aluminum alloy braided layer are filled with aviation lubricating grease. According to the conductive gasket, the aluminum alloy braided layer with light weight and good conductivity is adopted, and aviation lubricating grease is used for filling and emptying the meshes of the aluminum alloy braided layer, so that strong current generated when an airplane is hit by lightning can be efficiently conducted, and heat can be effectively dissipated; and electromagnetic interference and radiation generated in a complex electromagnetic wave environment are blocked, static electricity removal of static electricity accumulation is prevented, electric spark and thermal damage phenomena in a maintenance cover plate area are avoided, and the risk of an aircraft fuel system is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of lightning protection and electromagnetic compatibility, in particular to a conductive gasket used for a maintenance cover plate of an aircraft fuel tank cap to resist lightning impact. Background Art

[0002] As we all know, the aircraft's fuel system is a vital component of the aircraft. It is responsible for storing and transporting fuel to power the aircraft's engines. To ensure the safety and efficiency of the fuel system, the fuel tanks need to be inspected and maintained regularly.

[0003] Aircraft fuel tank access panels are located on the wings and fuselage of aircraft, providing maintenance personnel with access to the interior of the fuel tanks for necessary inspections and maintenance, ensuring the safe and efficient operation of the aircraft's fuel system. However, aircraft often fly through thunderstorm clouds. Lightning, as a high-energy natural phenomenon, poses a potential threat to aircraft structures, especially the fuel system. In particular, when struck by lightning, the current density in the access panel area is high, potentially generating sparks and becoming a potential ignition source. Furthermore, aircraft must adapt to various harsh environmental conditions during flight, such as electromagnetic environments and electrostatic protection. These complex environmental conditions pose new challenges to various aircraft components. For aircraft fuel tank access panels, it is essential to simultaneously perform these multiple functions. However, currently available fuel tank access panels still have certain limitations, such as poor electrical continuity, which can pose safety risks when the aircraft is exposed to lightning or electromagnetic interference. Utility Model Content

[0004] In view of this, the utility model proposes a conductive gasket for use in an aircraft fuel tank access cover to resist lightning impact, aiming to solve the problem that the existing aircraft fuel tank access cover has poor ability to cope with lightning environment and resist electromagnetic interference, and has certain safety hazards.

[0005] The utility model proposes a conductive gasket for resisting lightning strikes on a maintenance cover of an aircraft fuel tank cap, comprising an aluminum alloy braided layer and a connector fixedly arranged on the aluminum alloy braided layer. The aluminum alloy braided layers are connected end to end through the connector and are annular. The aluminum alloy braided layer is provided with a plurality of mounting through holes extending vertically therethrough, and the mesh holes of the aluminum alloy braided layer are filled with aviation lubricating grease.

[0006] Furthermore, the connecting member is a cotton thread sewing part, which is arranged at the connecting position of the head end and the tail end of the aluminum alloy braided layer, and the head end and the tail end of the aluminum alloy braided layer are fixedly connected by the cotton thread sewing part.

[0007] Furthermore, the aluminum alloy braided layer includes several layers of aluminum alloy braided meshes that are tightly fitted in sequence. The thickness of the aluminum alloy braided layer is 0.8±0.4 mm, and the radial width of the aluminum alloy braided layer is 26.0±0.5 mm.

[0008] Furthermore, the aluminum alloy braided layer includes 6 layers of aluminum alloy braided mesh, the mesh of the aluminum alloy braided mesh is square and the side length is 0.5~2.1mm, and the aluminum alloy braided layer is connected end to end to form a circular ring, an elliptical ring or a runway ring as a whole.

[0009] Furthermore, the connecting part is a fluorosilicone rubber elastomer, which includes an inner edge elastomer and an outer edge elastomer that are independently arranged and in a ring shape. The inner edge of the aluminum alloy braided layer is closed by the inner edge elastomer, and the outer edge of the aluminum alloy braided layer is closed by the outer edge elastomer. The aluminum alloy braided layer is connected end to end and in a ring shape through the limitation of the inner edge elastomer and the outer edge elastomer.

[0010] Furthermore, the inner edge elastic body includes an integrally formed and annular first inner edge elastic body and a second inner edge elastic body, the first inner edge elastic body being embedded in the mesh at the inner edge position and covering the inner edge, and the second inner edge elastic body being connected to the first inner edge elastic body and being located outside the aluminum alloy braided layer;

[0011] The outer edge elastic body includes a first outer edge elastic body and a second outer edge elastic body that are integrally formed and annular, wherein the first outer edge elastic body is embedded in the mesh at the outer edge position and covers the outer edge, and the second outer edge elastic body is connected to the first outer edge elastic body and is located outside the aluminum alloy braided layer;

[0012] The first inner elastic body and the first outer elastic body do not protrude from the surface of the aluminum alloy braided layer.

[0013] Furthermore, the radial width and thickness of the first inner edge elastomer and the first outer edge elastomer are the same, the radial width and thickness of the second inner edge elastomer and the second outer edge elastomer are the same, and the thickness of the first inner edge elastomer is greater than the thickness of the second inner edge elastomer.

[0014] Furthermore, the radial width of the first inner edge elastic body is 1.0±1.6 mm, the radial width of the second inner edge elastic body is 2.0±0.5 mm, and the thickness of the second inner edge elastic body is 0.5±0.4 mm.

[0015] Furthermore, the conductive gasket also includes a circular aluminum alloy braided mesh protection ring, and the aluminum alloy braided mesh protection ring tightly covers the edge of the mounting through hole.

[0016] Furthermore, the conductive pad also includes a circular ring-shaped fluorosilicone rubber third elastomer, which is embedded in the mesh of the aluminum alloy woven mesh protection ring and covers the aluminum alloy woven mesh protection ring. The fluorosilicone rubber third elastomer does not protrude from the surface of the aluminum alloy woven layer.

[0017] Compared to the prior art, the present invention provides a lightning-resistant conductive gasket for aircraft fuel tank access cover panels. The gasket comprises an aluminum alloy braided layer and a connector fixed to the aluminum alloy braided layer. The aluminum alloy braided layer is connected end to end by the connector and forms a ring. The aluminum alloy braided layer is provided with a plurality of mounting holes extending vertically therethrough, and the mesh of the aluminum alloy braided layer is filled with aviation grease. The conductive gasket is positioned below the aircraft fuel tank access cover panel and fastened to the access opening of the fuel tank access cover panel using fasteners through the mounting holes. The conductive gasket utilizes a lightweight and highly conductive aluminum alloy braided layer, combined with aviation grease filled and drained within the mesh of the aluminum alloy braided layer. The gasket effectively conducts the high current and heat generated by lightning strikes on aircraft, blocks electromagnetic interference and radiation generated in complex electromagnetic environments, and prevents static electricity accumulation by dissipating static electricity. This prevents sparks and thermal damage in the access cover panel area, thereby reducing risks to the aircraft's fuel system. It can be seen that the application of this conductive gasket on the aircraft fuel tank cap maintenance cover can significantly improve the safety performance of the aircraft fuel tank cap maintenance cover in lightning environments and electromagnetic interference environments, and further enhance the flight safety level of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0019] Figure 1 A schematic structural diagram of an embodiment of a conductive gasket for protecting a maintenance cover of an aircraft fuel tank cap provided by the present invention from lightning strikes;

[0020] Figure 2 for Figure 1 Schematic diagram of the structure of the local A;

[0021] Figure 3 for Figure 1 Cross-sectional view of the middle BB plane;

[0022] Figure 4A schematic structural diagram of another embodiment of the conductive gasket for resisting lightning strikes applied to a maintenance cover of an aircraft fuel tank cap provided by the present invention;

[0023] Figure 5 for Figure 4 Schematic diagram of the structure of the local A;

[0024] Figure 6 for Figure 4 Cross-sectional view of the middle BB plane;

[0025] Figure 7 A schematic structural diagram of another embodiment of the conductive gasket for protecting against lightning strikes applied to a maintenance cover of an aircraft fuel tank cap provided by the present invention;

[0026] Figure 8 for Figure 7 Schematic diagram of the structure of the local A;

[0027] Figure 9 for Figure 7 Cross-sectional view of the middle BB plane;

[0028] Description of Figure Numbers:

[0029] 10-conductive pad, 11-aluminum alloy braided layer, 12-cotton thread suture part, 13-mounting through hole, 14-fluorosilicone rubber elastomer, 141-inner edge elastomer, 142-outer edge elastomer, 1411-first inner edge elastomer, 1412-second inner edge elastomer, 1421-first outer edge elastomer, 1422-second outer edge elastomer, 15-aluminum alloy braided mesh protection ring, 143-fluorosilicone rubber third elastomer. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the schemes in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0032] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0033] The present invention proposes a conductive gasket 10 for use in an aircraft fuel tank access cover maintenance panel to protect against lightning strikes, comprising an aluminum alloy braided layer 11 and a connector fixedly disposed on the aluminum alloy braided layer 11. The aluminum alloy braided layer 11 is connected end to end through the connector and is annular. The aluminum alloy braided layer 11 is provided with a plurality of mounting through holes 13 extending vertically therethrough. The mesh of the aluminum alloy braided layer 11 is filled with aviation lubricating grease.

[0034] Specifically, the aircraft fuel tank access cover maintenance cover is designed to ensure the safety and efficiency of the aircraft fuel system while facilitating maintenance personnel to perform necessary maintenance and inspections and providing access to the interior of the fuel tank.

[0035] Specifically, the aluminum alloy braided layer 11 is a mesh braided structure woven from 5056 aluminum alloy wire. 5056 aluminum alloy wire is an aluminum alloy material, mainly composed of aluminum and magnesium, wherein the magnesium content is about 4% to 5%, and also contains a small amount of nickel and chromium. Lightweighting has always been one of the standards for aircraft design. The overall mass of an aircraft affects aspects such as flight energy consumption and maneuverability. Therefore, the selected material needs to have a lighter weight while ensuring performance. The specific gravity of 5056 aluminum alloy wire is 1 / 2 of ferrite and 1 / 3 of materials such as Monel 405 and copper. It has a light unit mass and strong plasticity. In addition, 5056 aluminum alloy wire has good corrosion resistance and strength, and is suitable for various application fields, such as aerospace, shipbuilding, and the automotive industry.

[0036] In terms of mechanical properties, 5056 aluminum alloy wire does not have the excessive tensile strength of stainless steel, nor the low tensile strength of copper, and its yield strength is also moderate. These appropriate tensile and yield strengths ensure that the aluminum alloy braid 11 does not break directly due to excessive brittleness when subjected to complex alternating forces, nor does it fail to meet performance requirements due to excessive toughness. Installing the conductive gasket 10 made of 5056 aluminum alloy wire between the fuel tank access cover and the aircraft fuselage effectively withstands the various vibrations and compressions experienced during flight.

[0037] In terms of thermal properties, the thermal expansion coefficient of 5056 aluminum alloy wire is greater than that of other metal materials, and its thermal conductivity is also better than that of most metal materials. This enables the aluminum alloy braided layer 11 to quickly and evenly transfer heat when subjected to strong electric shock heating, preventing the aluminum alloy braided layer 11 from melting due to excessive heat.

[0038] In terms of electrical performance, when an aircraft encounters severe thunderstorms during flight, strong lightning strikes may directly cause the fuel tank to rupture or be damaged, affecting the normal flight of the aircraft. In more serious cases, it may even ignite the fuel and affect personal safety. The principle of lightning resistance of the conductive pad 10 provided by the utility model is that when lightning strikes the aircraft, the strong current brought by the lightning forms a closed loop through the aluminum alloy braided layer 11, causing it to attenuate and dissipate, thereby protecting the fuel tank from being damaged or igniting the fuel. Therefore, it is very necessary for the aluminum alloy braided layer 11 to have a low resistivity. The lower the resistivity, the higher its conductivity, the better the conductive continuity, and the better the lightning resistance effect. The resistivity of 5056 aluminum alloy wire is significantly lower than that of other metal materials. Therefore, using 5056 aluminum alloy wire as the braiding material of the aluminum alloy braided layer 11 can largely avoid the fault of electric sparks generated in the maintenance cover area when a lightning strike occurs.

[0039] In addition to lightning strikes, various electromagnetic radiation interference and clutter in the air or on the ground during high-altitude flight can easily induce currents in the aircraft's fuel tanks due to energy fields, increasing the probability of sparks and posing a potential risk to the aircraft's safe operation. To prevent the generation of induced currents, an aluminum alloy braided layer 11 is provided at the fuel tank cap interface to provide effective protection and shielding against electromagnetic interference and external clutter, while also providing efficient static dissipation. The smaller the mesh size of the aluminum alloy braided layer 11, the greater its electromagnetic shielding advantage. The aluminum alloy braided layer 11 used in the conductive gasket 10 provided in the present invention is woven from small-mesh 5056 aluminum alloy wire (square mesh with a side length of 0.5-2.1 mm, and a diameter of 0.127 mm). The mesh count per inch (per 2.54 cm) is 12 ± 2. To ensure high shielding effectiveness across a wide frequency range, the aluminum alloy braided layer 11 also utilizes a multi-layer shielding approach. Specifically, the aluminum alloy braided layer 11 comprises six layers of aluminum alloy braided mesh, with each two layers being concentrically braided to ensure good elasticity and compression-deformation characteristics.

[0040] It should be noted that aviation grease is used to fill and drain the mesh of the aluminum alloy braided layer 11. By filling and draining the mesh of each layer of aluminum alloy braided layer 11 with aviation grease, efficient current conduction is achieved. The combination of aluminum alloy braided layer 11 and aviation grease ensures rapid conduction of lightning current within the conductive gasket 10 and effective heat dissipation, minimizing impact on the fuel tank cap and internal structures, and reducing electrical resistance and thermal damage. The aviation grease filling reduces contact resistance between materials, preventing overheating and material ablation caused by excessive resistance. It also effectively suppresses sparking between the 5056 aluminum alloy wires when dense current passes through them.

[0041] Furthermore, the aluminum alloy braid 11 is provided with several vertically extending mounting holes 13. These mounting holes 13 are designed to facilitate the insertion of fasteners and secure the conductive gasket 10 to the aircraft fuselage. Through these mounting holes 13, fasteners can easily pass through the aluminum alloy braid 11 without damaging the overall structure of the conductive gasket 10, securely securing the conductive gasket 10 to the aircraft fuel tank access panel and ensuring its stability. The provision of mounting holes 13 not only simplifies the installation process but also improves the overall structural stability and safety of the conductive gasket 10, providing enhanced protection and performance for high-altitude flight.

[0042] Compared to the prior art, the conductive gasket 10 is disposed below the aircraft fuel tank cap maintenance cover and fasteners are used to install it to the aircraft fuel tank cap maintenance cover channel through the mounting holes 13 of the conductive gasket 10. The conductive gasket 10 uses a lightweight and highly conductive aluminum alloy braided layer 11, combined with aviation lubricating grease filled and emptied in the mesh of the aluminum alloy braided layer 11. This can effectively conduct the strong current and heat generated when the aircraft is struck by lightning, effectively dissipate it, and block electromagnetic interference and radiation generated in complex electromagnetic wave environments, and prevent static electricity accumulation. This can avoid electric sparks and thermal damage in the maintenance cover area, thereby reducing the risk to the aircraft fuel system. It can be seen that the application of the conductive gasket 10 on the aircraft fuel tank cap maintenance cover can significantly improve the safety performance of the aircraft fuel tank cap maintenance cover in lightning environments and electromagnetic interference environments, further improving the flight safety level of the aircraft.

[0043] Please refer to Figure 1 , which is a structural schematic diagram of an embodiment of a conductive gasket 10 for protecting a maintenance cover of an aircraft fuel tank cap from lightning strikes provided by the present invention.

[0044] In some embodiments of the present application, the connecting member is a cotton thread suture portion 12, which is arranged at the junction of the head end and the tail end of the aluminum alloy braided layer 11, and the head end and the tail end of the aluminum alloy braided layer 11 are fixedly connected by the cotton thread suture portion 12.

[0045] Specifically, cotton thread is a soft yet durable material. Stitching the aluminum alloy braided layer 11 with cotton thread to form the cotton thread stitching portion 12 provides additional support for the front and rear ends of the aluminum alloy braided layer 11, making the end-to-end connection of the aluminum alloy braided layer 11 more secure and stable, and preventing deformation or cracking. Furthermore, stitching with cotton thread can smooth the end-to-end connection, reduce protrusions, and maintain the flatness of the conductive gasket 10. Furthermore, cotton thread has good wear resistance and durability, and can withstand certain tension and pressure, further extending the service life of the conductive gasket 10.

[0046] Please refer to Figure 2 and Figure 3 As shown, it is Figure 1 Structural diagram of part A and cross-sectional view of surface BB.

[0047] In some embodiments of the present application, the aluminum alloy braided layer 11 includes several layers of aluminum alloy braided meshes that are tightly fitted in sequence. The thickness of the aluminum alloy braided layer 11 is 0.8±0.4 mm, and the radial width of the aluminum alloy braided layer 11 is 26.0±0.5 mm.

[0048] Specifically, the aluminum alloy braided layer 11 is designed to comprise several layers of tightly fitted aluminum alloy mesh to provide greater lightning strike resistance and longer life. By employing a multi-layer, densely packed flow-guiding approach, it effectively resists lightning strikes while simultaneously preventing the ingress of external electromagnetic interference and reducing the leakage of internal electromagnetic radiation. Each layer of aluminum alloy mesh absorbs and reflects some electromagnetic waves, and the tightly fitted design enhances shielding effectiveness, ensuring excellent shielding performance across a wider frequency range, helping the aircraft operate normally in complex electromagnetic environments.

[0049] Specifically, the thickness and radial width of the aluminum alloy braided layer 11 are within a range suitable for common aircraft models on the market and can be used with a variety of existing aircraft fuel tank access cover panels, thereby enhancing the versatility and interchangeability of the conductive gasket 10. Conductive gaskets 10 of this size are also more easily accepted by the market, thereby improving the product's feasibility.

[0050] In some embodiments of the present application, the aluminum alloy braided layer 11 includes 6 layers of aluminum alloy braided mesh, the mesh of the aluminum alloy braided mesh is square and the side length is 0.5~2.1mm, and the aluminum alloy braided layer 11 is connected end to end to form a circular ring, an elliptical ring or a runway ring as a whole.

[0051] Specifically, a runway ring refers to a circular or elliptical shape surrounding the centerline of the runway. To accommodate the structures of different aircraft and fuel tanks on the market, aircraft fuel tank cap maintenance covers have various shapes. To accommodate aircraft fuel tank cap maintenance covers of various shapes, it is necessary to design conductive gaskets 10 of various shapes. Applying the conductive gasket 10 provided by the present invention to a matching aircraft fuel tank cap maintenance cover ensures the tightness and stability of the aircraft fuel tank cap maintenance cover and the fuel tank opening, while meeting the installation requirements of different aircraft models and improving the adaptability of the product.

[0052] Please refer to Figure 4 , which is a structural schematic diagram of another embodiment of the conductive gasket 10 provided by the present invention for resisting lightning strikes on a maintenance cover of an aircraft fuel tank cap.

[0053] In some embodiments of the present application, the connecting part is a fluorosilicone rubber elastomer 14, which includes an inner edge elastomer 141 and an outer edge elastomer 142 that are independently arranged and annular. The inner edge of the aluminum alloy braided layer 11 is closed by the inner edge elastomer 141, and the outer edge of the aluminum alloy braided layer 11 is closed by the outer edge elastomer 142. The inner edge elastomer 141 and the outer edge elastomer 142 are limited so that the aluminum alloy braided layer 11 is connected from head to tail and is annular.

[0054] Specifically, the fluorosilicone rubber elastomer 14 is a uniform mixture of silicone rubber elastomer as the base rubber and various fillers and additives. It has high strength and resilience, excellent oil resistance, solvent resistance and high and low temperature resistance, and can be used normally in the temperature range of -55°C to 70°C.

[0055] Specifically, the inner edge of the aluminum alloy braided layer 11 is enclosed by the inner edge elastomer 141. The outer edge of the aluminum alloy braided layer 11 is enclosed by the outer edge elastomer 142. This design helps to fix the shape of the aluminum alloy braided layer 11. Even if no additional connection structure is provided at the connection position of the head end and the tail end, the structural stability of the conductive gasket 10 can be maintained to avoid deformation and detachment. Moreover, the conductive gasket 10 itself is relatively light and thin. Without the reinforcement of the inner edge elastomer 141 and the outer edge elastomer 142, it is very easy to deform, which is not conducive to subsequent installation and reuse. The role of the inner edge elastomer 141 and the outer edge elastomer 142 is similar to a frame, providing support and protection for the aluminum alloy braided layer 11, ensuring that it maintains integrity and functionality during use. The inner edge elastomer 141 and the outer edge elastomer 142 have anti-deformation capabilities, which can enhance the mechanical properties of the conductive gasket 10 and extend its service life.

[0056] Specifically, a fluorosilicone rubber elastomer 14 is added to the edge of the aluminum alloy braided layer 11 to seal the aluminum alloy braided layer 11. The fluorosilicone rubber elastomer 14 itself has excellent elasticity. Combined with the flexibility of the aluminum alloy braided layer 11, it can help the aircraft fuel tank cover maintenance cover provide a better sealing effect and alleviate friction between the aircraft fuel tank cover maintenance cover and the aircraft fuselage. It can well adapt to various vibrations and extrusions during the aircraft's flight, and improve the durability and safety of the conductive gasket 10. At the same time, the fluorosilicone rubber elastomer 14 also has excellent weather resistance and can withstand the extreme high and low temperature environments that aircraft occasionally encounter during flight. It not only extends the service life of the conductive gasket 10, but also greatly improves the flight safety of the aircraft.

[0057] Please refer to Figure 5 and Figure 6 As shown, it is Figure 4 Structural diagram of part A and cross-sectional view of surface BB.

[0058] In some embodiments of the present application, the inner edge elastic body 141 includes an integrally formed, annular first inner edge elastic body 1411 and a second inner edge elastic body 1412. The first inner edge elastic body 1411 is embedded in the mesh at the inner edge position and covers the inner edge. The second inner edge elastic body 1412 is connected to the first inner edge elastic body 1411 and is located outside the aluminum alloy braided layer 11.

[0059] The outer elastic body 142 includes an integrally formed annular first outer elastic body 1421 and a second outer elastic body 1422. The first outer elastic body 1421 is embedded in the mesh at the outer edge and covers the outer edge. The second outer elastic body 1422 is connected to the first outer elastic body 1421 and is located outside the aluminum alloy braided layer 11.

[0060] The first inner elastic body 1411 and the first outer elastic body 1421 do not protrude from the surface of the aluminum alloy braided layer 11 .

[0061] Specifically, by embedding the first inner elastic body 1411 within and covering the inner edge of the aluminum alloy braided layer 11, the connection between the first inner elastic body 1411 and the aluminum alloy braided layer 11 is ensured to be more secure, less likely to loosen or fall off, and the fixation and stability of the aluminum alloy braided layer 11 are enhanced. Furthermore, when the first inner elastic body 1411 is embedded within and covers the inner edge of the aluminum alloy braided layer 11, it does not protrude beyond the surface of the aluminum alloy braided layer 11, thus not affecting the original thickness of the aluminum alloy braided layer 11. This maintains the flatness and consistency of the overall structure of the conductive gasket 10. On the other hand, the second inner edge elastomer 1412 is connected to the outside of the first inner edge elastomer 1411, that is, the second inner edge elastomer 1412 extends to the outside of the first inner edge elastomer 1411. This is a one-step design structure, which can effectively reduce the internal stress concentration of the fluorosilicone rubber elastomer 14 and improve the stability and durability of the connection. At the same time, the one-step structure can also improve the sealing of the connection, forming a better sealing effect, preventing external impurities or liquids from penetrating, and protecting the interior of the fuel tank from the influence of the external environment. The double elastomer design of the inner edge elastomer 141 can ensure that the various parts of the inner edge elastomer 141 are firmly connected, reducing wear and fatigue at a single connection point, extending the service life and improving overall durability. This design helps to improve the durability and stability of the conductive gasket 10, ensuring that it can function effectively during use. It should be noted that the same design principle also applies to the outer edge elastomer 142, and no further examples will be given here.

[0062] In some embodiments of the present application, the radial width and thickness of the first inner edge elastomer 1411 and the first outer edge elastomer 1421 are the same, the radial width and thickness of the second inner edge elastomer 1412 and the second outer edge elastomer 1422 are the same, and the thickness of the first inner edge elastomer 1411 is greater than the thickness of the second inner edge elastomer 1412.

[0063] Specifically, the structural design that allows the inner edge elastomer 141 and the outer edge elastomer 142 to maintain consistency can make the overall structure of the conductive pad 10 more unified and coordinated. This consistency design can enhance the aesthetic appearance and overall quality of the product, while simplifying the manufacturing process, reducing the complexity in production, improving production efficiency, and reducing production costs. The design of the one-level stepped structure in which the thickness of the first inner edge elastomer 1411 is greater than the thickness of the second inner edge elastomer 1412 is intended to better adapt to the various vibrations and extrusions of the aircraft during flight during the connection process. By rationally designing the inner edge elastomers 141 of different thicknesses, it is possible to achieve balanced pressure distribution and improved durability while ensuring connection stability. It should be noted that the same design principle also applies to the outer edge elastomer 142, and no further examples will be given here.

[0064] In some embodiments of the present application, the radial width of the first inner edge elastic body 1411 is 1.0±1.6 mm, the radial width of the second inner edge elastic body 1412 is 2.0±0.5 mm, and the thickness of the second inner edge elastic body 1412 is 0.5±0.4 mm.

[0065] Specifically, the size range of the first inner edge elastic body 1411 and the second inner edge elastic body 1412 is adapted to common aircraft models on the market, and can be applied to a variety of existing aircraft fuel tank cover maintenance covers on the market, thereby improving the versatility, interchangeability and feasibility of the conductive gasket 10.

[0066] It should be noted that all dimensions of the conductive gasket 10 are designed to effectively cover the contact surface of the aircraft fuel tank access cover. When used on an aircraft fuel tank access cover, the conductive gasket 10 is neither too wide to hinder installation nor too high to cause the cover to protrude from the aircraft's exterior. This design ensures that the conductive gasket 10 fits perfectly with the aircraft's exterior after installation, preventing protrusions or instability, further ensuring the safety of the fuel tank access cover in lightning and other environments with unknown electromagnetic interference.

[0067] Please refer to Figure 7 , which is a structural schematic diagram of another embodiment of the conductive gasket 10 provided by the present invention for resisting lightning strikes on a maintenance cover of an aircraft fuel tank cap.

[0068] In some embodiments of the present application, the conductive gasket 10 further includes a circular aluminum alloy braided mesh protection ring 15 , and the aluminum alloy braided mesh protection ring 15 tightly covers the edge of the mounting through hole 13 .

[0069] Specifically, an aluminum alloy braided mesh protective ring 15 is positioned around the edge of the mounting hole 13. This tightly wraps around the edge of the mounting hole 13, forming a protective layer that effectively prevents the edge of the mounting hole 13 from damage or deformation due to friction or collision, further extending the service life of the conductive gasket 10. Furthermore, the aluminum alloy braided mesh protective ring 15 itself possesses a certain degree of strength and stability, providing support and reinforcement around the mounting hole 13, enhancing the stability and strength of the overall structure. Finally, the aluminum alloy braided mesh protective ring 15 also beautifies the edge of the mounting hole 13, making the overall appearance more neat and aesthetically pleasing, and improving the visual quality of the product.

[0070] Please refer to Figure 8 and Figure 9 As shown, it is Figure 7 Structural diagram of part A and cross-sectional view of surface BB.

[0071] In some embodiments of the present application, the conductive pad 10 also includes a circular-shaped fluorosilicone rubber third elastomer 143, which is embedded in the mesh of the aluminum alloy woven mesh protective ring 15 and covers the aluminum alloy woven mesh protective ring 15. The fluorosilicone rubber third elastomer 143 does not protrude from the surface of the aluminum alloy woven layer 11.

[0072] Specifically, the third fluorosilicone rubber elastomer 143 is embedded in the mesh of the aluminum alloy braided mesh protective ring 15 and covers the aluminum alloy braided mesh protective ring 15, further enhancing the structural stability of the aluminum alloy braided mesh protective ring 15 and making the connection between the aluminum alloy braided mesh protective ring 15 and the mounting hole 13 more secure, preventing loosening or falling off. Furthermore, the additional third fluorosilicone rubber elastomer 143 can help balance the connection pressure from the fasteners on the mounting hole 13, reducing localized pressure concentration and thus improving the stability of the overall structure. This design helps ensure that the overall shape of the aluminum alloy braided layer 11 remains stable, allowing it to continue to function effectively during use.

[0073] In some embodiments of the present application, the mounting through hole 13 is circular and has a hole diameter of 7-8 mm.

[0074] Specifically, the installation through-hole 13 is provided to facilitate the insertion of fasteners and further facilitate the installation of the maintenance cover. The aperture of the installation through-hole 13 is usually selected to a suitable size according to the size and requirements of the fastener. The installation through-hole 13 with an aperture of 7 to 8 mm can be adapted to most aircraft fasteners on the market, including common screws and nuts. The aperture of 7 to 8 mm can accommodate fasteners and provide sufficient support and fixing force to ensure that the fasteners are firmly installed in the installation through-hole 13, thereby simplifying the installation process and improving the reliability of the connection. Such a design takes into account the installation requirements of the fasteners, while taking into account the structural stability and adaptability of the installation through-hole 13, providing convenience for the installation and maintenance of aircraft components.

[0075] The lightning-resistant conductive gasket 10 provided in this embodiment, applied to an aircraft fuel tank access cover, improves the safety of the fuel tank access cover in lightning and other unidentified electromagnetic interference environments, enhancing its lightning protection and electromagnetic interference resistance, and effectively reducing the risks to aircraft in these environments. This innovative design not only improves the fuel tank access cover's ability to withstand lightning strikes and electromagnetic interference, but also enhances the environmental adaptability of the conductive gasket 10, improving the aircraft's flight safety and providing more reliable protection for the safety of pilots and passengers.

[0076] The conductive gasket 10 provided in this embodiment is designed to protect against lightning strikes on aircraft fuel tank access panels. It is installed at the interface between the fuel tank access panel and the aircraft's fuselage skin and is secured to the access opening of the aircraft's fuel tank access panel using fasteners through mounting holes 13. This conductive gasket 10 utilizes a high-performance aluminum alloy braided layer 11, composited with a fluorosilicone rubber material that is resistant to high and low temperatures and highly adaptable to corrosion environments, and filled with aviation lubricant. These materials leverage their respective strengths, achieving a synergistic effect that improves product performance, resulting in a novel composite conductive gasket 10 that combines electrical conductivity, sealing, and environmental adaptability. This conductive gasket 10 rapidly conducts lightning current, preventing current accumulation at the fuel tank access panel and reducing the risk of lightning strikes to the aircraft structure and fuel system. It also provides excellent EMI (electromagnetic interference) shielding and static dissipation capabilities, effectively blocking the conduction and radiation of electromagnetic interference and providing a path for static charge discharge. It can rapidly direct electromagnetic energy and static charge into the aircraft's low-voltage fuselage, ensuring fuel system safety. The conductive gasket 10 also offers certain sealing properties. The fluorosilicone rubber elastomer 14 possesses excellent elasticity, resilience, and deformation resistance. Combined with the aviation grease filling, it further prevents fuel leakage and foreign material infiltration, providing reliable multi-layer protection. This lightning-resistant conductive gasket 10, used in aircraft fuel tank access panels, is designed to enhance their lightning surge resistance, EMI shielding, anti-static properties, and sealing capabilities. This addresses the safety concerns of existing aircraft fuel tank access panels, which often struggle with harsh environments and present certain safety risks.

[0077] It should be noted that the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0078] The above description is only part or preferred embodiments of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A conductive gasket for protecting the fuel tank cover of an aircraft from lightning strikes, characterized in that: The invention comprises an aluminum alloy braided layer and a connector fixedly arranged on the aluminum alloy braided layer. The aluminum alloy braided layer is connected end to end through the connector and is in a ring shape. The aluminum alloy braided layer is provided with a plurality of mounting through holes which pass through the aluminum alloy braided layer from top to bottom. The mesh of the aluminum alloy braided layer is filled with aviation lubricating grease.

2. The conductive gasket for resisting lightning strikes applied to the maintenance cover of an aircraft fuel tank cap according to claim 1 is characterized in that: The connecting piece is a cotton thread sewing part, which is arranged at the connecting position of the head end and the tail end of the aluminum alloy braided layer. The head end and the tail end of the aluminum alloy braided layer are fixedly connected by the cotton thread sewing part.

3. The conductive gasket for resisting lightning strikes applied to the maintenance cover of an aircraft fuel tank cap according to claim 1 is characterized in that: The aluminum alloy braided layer includes several layers of aluminum alloy braided meshes that are tightly fitted in sequence. The thickness of the aluminum alloy braided layer is 0.8±0.4 mm, and the radial width of the aluminum alloy braided layer is 26.0±0.5 mm.

4. The conductive gasket for resisting lightning strikes applied to the maintenance cover of an aircraft fuel tank cap according to claim 3 is characterized in that: The aluminum alloy braided layer includes 6 layers of aluminum alloy braided mesh, the mesh of the aluminum alloy braided mesh is square and the side length is 0.5-2.1 mm. When the aluminum alloy braided layers are connected end to end, the overall shape is a circular ring, an elliptical ring or a runway ring.

5. The conductive gasket for resisting lightning strikes applied to the maintenance cover of an aircraft fuel tank cap according to claim 1 is characterized in that: The connecting piece is a fluorosilicone rubber elastomer, which includes an inner edge elastomer and an outer edge elastomer that are independently arranged and annular. The inner edge of the aluminum alloy braided layer is closed by the inner edge elastomer, and the outer edge of the aluminum alloy braided layer is closed by the outer edge elastomer. The aluminum alloy braided layer is connected end to end and formed into a ring through the limitation of the inner edge elastomer and the outer edge elastomer.

6. The conductive gasket for lightning protection used in the maintenance cover of an aircraft fuel tank cap according to claim 5, characterized in that: The inner edge elastic body includes a first inner edge elastic body and a second inner edge elastic body that are integrally formed and annular, wherein the first inner edge elastic body is embedded in the mesh at the inner edge position and covers the inner edge, and the second inner edge elastic body is connected to the first inner edge elastic body and is located outside the aluminum alloy braided layer; The outer edge elastic body includes a first outer edge elastic body and a second outer edge elastic body that are integrally formed and annular, wherein the first outer edge elastic body is embedded in the mesh at the outer edge position and covers the outer edge, and the second outer edge elastic body is connected to the first outer edge elastic body and is located outside the aluminum alloy braided layer; The first inner elastic body and the first outer elastic body do not protrude from the surface of the aluminum alloy braided layer.

7. The conductive gasket for resisting lightning strikes applied to the maintenance cover of an aircraft fuel tank cap according to claim 6, characterized in that: The first inner edge elastomer and the first outer edge elastomer have the same radial width and thickness, the second inner edge elastomer and the second outer edge elastomer have the same radial width and thickness, and the thickness of the first inner edge elastomer is greater than that of the second inner edge elastomer.

8. The conductive gasket for resisting lightning strikes applied to the maintenance cover of an aircraft fuel tank cap according to claim 7 is characterized in that: The radial width of the first inner elastic body is 1.0±1.6 mm, the radial width of the second inner elastic body is 2.0±0.5 mm, and the thickness of the second inner elastic body is 0.5±0.4 mm.

9. The conductive gasket for resisting lightning strikes applied to the maintenance cover of an aircraft fuel tank cap according to claim 1, characterized in that: The conductive gasket further includes a circular aluminum alloy braided mesh protection ring, which tightly covers the edge of the mounting through hole.

10. The conductive gasket for resisting lightning strikes applied to the maintenance cover of an aircraft fuel tank cap according to claim 9, characterized in that: The conductive pad also includes a circular fluorosilicone rubber third elastomer, which is embedded in the mesh of the aluminum alloy braided mesh protection ring and covers the aluminum alloy braided mesh protection ring. The fluorosilicone rubber third elastomer does not protrude from the surface of the aluminum alloy braided layer.

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