Aircraft gravity filler cap with electric lap joint and lightning protection functions

By incorporating conductive components and high dielectric strength materials into the aircraft gravity refueling port cover, the problem of poor electrical bonding during lightning strikes is solved, ensuring that the sealing surface is not burned and improving aircraft safety.

CN121044056APending Publication Date: 2025-12-02CHENGDU CHENGHANG AUTO-INSTR CO LTD
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Patent Information

Application Number
CN202511026600.X
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-07-24
Publication Date
2025-12-02

AI Technical Summary

Technical Problem

Traditional gravity refueling caps are susceptible to damage from lightning strikes due to poor electrical bonding, which can lead to erosion of the sealing surface, affecting the seal and posing a risk of fuel leakage, thus threatening aircraft safety.

Method used

Design an aircraft gravity refueling port cover that combines electrical connection and lightning protection. By setting a conductive element on a metal base and electrically connecting it to the cover seat, and using a high dielectric strength material to manufacture the lower cover, the conductive element conducts the charge to the outer wall of the fuel tank, preventing high voltage arc from burning the sealing surface.

Benefits of technology

It enables charge conduction during lightning strikes, preventing erosion of sealing surfaces, ensuring airtightness, preventing fuel leakage, and improving aircraft safety.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention discloses an aircraft gravity filler cap with electric lap joint and lightning protection functions, and belongs to the technical field of aircraft gravity refueling. The aircraft gravity filler cap with the electric lap joint and lightning protection functions comprises a filler cap seat, an upper cover assembly and a lower cover; the upper cover assembly is provided with a conductive piece making contact with the covering cap base. The lower cover is made of a high dielectric strength material; the metal base and the covering cap seat are in electric lap joint through the conductive part, when the whole aircraft gravity filler cap is struck by lightning, the conductive part conducts electric charges to the covering cap seat and the outer wall of an oil tank, and therefore the sealing face of the covering cap seat is prevented from being ablated by high-voltage electric arcs when the aircraft gravity filler cap is struck by lightning, and personnel and equipment are prevented from being damaged by residual electric charges. The lower cover is located in the oil tank and is made of high dielectric strength materials, electric fire is prevented from occurring in the oil tank of the gravity oil filler cover under the direct thunder and lightning action, and the problems that a traditional gravity oil filler cover does not have good electric lap joint performance, and a sealing face of a cover seat is ablated by high-voltage arcs when the traditional gravity oil filler cover is subjected to the thunder and lightning are solved.
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Description

Technical Field

[0001] This invention belongs to the field of aircraft gravity refueling technology, specifically relating to an aircraft gravity refueling port cover that combines electrical connection and lightning protection functions. Background Technology

[0002] Gravity refueling caps have a wide and crucial application in aircraft fuel tanks, facilitating rapid refueling during takeoff and landing. To further improve refueling efficiency during takeoff and landing, some aircraft do not have skin coverings on the gravity refueling caps. However, this design exposes the gravity refueling caps to the elements, posing a risk of lightning strikes.

[0003] Currently, mainstream lightning-resistant gravity refueling caps use insulating materials to protect the interior of the fuel tank. Furthermore, because gravity refueling caps require a self-locking function, there is an installation gap between the external metal fuselage of the fuel tank and the cap holder. This gap prevents a proper electrical connection between the gravity refueling cap and its holder. When the aircraft is struck by lightning, a high-voltage arc will form between the metal fuselage of the gravity refueling cap and the holder. This high-voltage arc possesses immense energy and can erode the sealing surface of the cap holder. Once the sealing surface is eroded, its sealing performance will be compromised during reassembly, potentially leading to serious problems such as fuel leakage and threatening flight safety. Summary of the Invention

[0004] Based on the problems existing in the above-mentioned background technology, the present invention proposes an aircraft gravity refueling port cover that has both electrical connection and lightning protection functions, which solves the problem that traditional gravity refueling port covers do not have good electrical connection performance and that the high voltage arc burns the sealing surface of the port cover seat when subjected to lightning strikes.

[0005] The embodiments of the present invention are implemented as follows: The present invention provides an aircraft gravity refueling port cover with both electrical connection and lightning protection functions, comprising a port cover base, an upper cover assembly, and a lower cover; the port cover base is fixedly disposed at the fuel tank opening, and the port cover base is fixedly connected to the outer wall of the aircraft around its perimeter; the upper cover assembly includes a metal base and an insulating cover plate disposed inside the port cover base, the metal base being located outside the fuel tank, and the insulating cover plate being located inside the fuel tank, with the perimeter edges of the metal base and the insulating cover plate being sealed to the inner wall of the port cover base; the lower cover is located inside the fuel tank and connected to the bottom of the upper cover assembly; the port cover base is made of a conductive material; a conductive element is disposed on the metal base, and the conductive element is in contact with the port cover base.

[0006] Furthermore, the metal base and the insulating cover plate are sealed to the inner wall of the cover seat at their four edges by sealing rings.

[0007] Furthermore, the upper surface of the cover seat is flush with the upper surface of the metal base.

[0008] Furthermore, the conductive element is an L-shaped elastic element. The horizontal end of the L-shaped elastic element is fixedly connected to the upper surface of the metal base by a metal screw, and the vertical end of the L-shaped elastic element is located between the cap seat and the metal base and is in contact with the cap seat.

[0009] Furthermore, a handle is provided in the middle of the metal base, and a rotating shaft is provided inside the handle. The bottom of the rotating shaft is fixedly connected to the lower cover.

[0010] Furthermore, both the handle and the pivot are made of conductive materials.

[0011] Furthermore, the lower cover is made of a high dielectric strength material.

[0012] Furthermore, the edge of the horizontal end of the L-shaped elastic element extends 0.1mm to 0.3mm beyond the inner wall of the cap seat.

[0013] Compared with traditional gravity-operated filler caps, the advantages of this invention are: This invention provides an aircraft gravity refueling cap with both electrical connection and lightning protection functions. By incorporating a conductive element on a metal base, the element electrically connects the metal base to the cap seat. When the entire gravity refueling cap is struck by lightning, the conductive element conducts the charge to the cap seat and the outer wall of the fuel tank, thus preventing high-voltage arcing during a lightning strike from eroding the sealing surface of the cap seat and preventing residual charge from harming personnel and equipment. The lower cap, located inside the fuel tank and made of a high-dielectric-strength material, prevents electrical sparks from occurring inside the fuel tank under direct lightning strikes, thus providing lightning protection. This solves the problem of traditional gravity refueling caps lacking good electrical connection performance and causing high-voltage arcing to erode the sealing surface of the cap seat during lightning strikes. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The above and other objects, features, and advantages of the present invention will become clearer through the accompanying drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not intentionally drawn to scale to actual dimensions; the focus is on illustrating the main points of the invention.

[0015] Figure 1 This is a cross-sectional schematic diagram illustrating the structural principle of an aircraft gravity refueling port cover that combines electrical connection and lightning protection functions.

[0016] Figure 2 for Figure 1 A magnified structural diagram of point A in the middle.

[0017] Among them, 1. Cover seat; 2. Upper cover assembly; 201. Metal base; 202. Insulating cover plate; 3. Lower cover; 4. Conductive component; 5. Sealing ring; 6. Handle; 7. Rotating shaft; 8. Metal screw. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0022] Please refer to Figures 1-2 As shown, the present invention provides an aircraft gravity refueling port cover that has both electrical connection and lightning protection functions, which includes a port cover seat 1, an upper cover assembly 2 and a lower cover 3.

[0023] The cover seat 1 is fixedly installed at the fuel tank opening, and the cover seat 1 is fixedly connected to the outer wall of the aircraft on all four sides. The upper cover assembly 2 includes a metal base 201 and an insulating cover plate 202 disposed inside the cover seat 1. The metal base 201 is located outside the fuel tank, and the insulating cover plate 202 is located inside the fuel tank. The upper surfaces of the cover seat 1 and the metal base 201 are flush. The edges of the metal base 201 and the insulating cover plate 202 are sealed to the inner wall of the cover seat 1. Specifically, the edges of the metal base 201 and the insulating cover plate 202 are sealed to the inner wall of the cover seat 1 by sealing rings 5.

[0024] The lower cover 3 is located inside the fuel tank and connected to the bottom of the upper cover assembly 2. As a specific connection method for the lower cover 3, a handle 6 is provided in the middle of the metal base 201. Both the handle 6 and the rotating shaft 7 are made of conductive materials. The rotating shaft 7 is located inside the handle 6, and the bottom of the rotating shaft 7 is fixedly connected to the lower cover 3. The lower cover 3 is located inside the fuel tank and is made of a high dielectric strength material to prevent electric sparks from occurring inside the fuel tank under direct lightning strikes, thus providing lightning protection. The handle 6 and the rotating shaft 7 facilitate opening or closing the aircraft's gravity refueling port cover.

[0025] The material of the cap seat 1 is conductive; a conductive element 4 is provided on the metal base 201, and the conductive element 4 is in contact with the cap seat 1. Further, as a specific arrangement of the conductive element 4, the conductive element 4 is an L-shaped elastic element. The horizontal end of the L-shaped elastic element is fixedly connected to the upper surface of the metal base 201 by a metal screw 8. Under the action of the metal screw 8, the L-shaped elastic element is tightly fitted to the upper surface of the metal base 201, and the vertical end of the L-shaped elastic element is located between the cap seat 1 and the metal base 201 and is in contact with the cap seat 1 under its own elastic force. Preferably, but not limited to, the edge of the horizontal end of the L-shaped elastic element extends beyond the inner wall of the cap seat 1 by 0.1mm to 0.3mm. The above arrangement ensures that after assembly, the L-shaped elastic element appears... Figure 2 The elastic deformation shown allows the L-shaped elastic element and the cap seat 1 to fit tightly together, ensuring electrical connection.

[0026] This invention provides an aircraft gravity refueling cap with both electrical connection and lightning protection functions. A conductive element 4 is installed on a metal base 201, electrically connecting the metal base 201 to the cap seat 1. When the entire aircraft gravity refueling cap is struck by lightning, the conductive element 4 conducts the charge to the cap seat 1 and the outer wall of the fuel tank, thereby preventing high-voltage arc erosion of the sealing surface of the cap seat 1 during a lightning strike and preventing residual charge from causing harm to personnel and equipment. The lower cover 3 is located inside the fuel tank and is made of a high-dielectric-strength material to prevent electric arcing inside the fuel tank under direct lightning strikes, thus providing lightning protection. This solves the problem of traditional gravity refueling caps lacking good electrical connection performance and causing high-voltage arc erosion of the sealing surface of the cap seat 1 during lightning strikes.

[0027] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An aircraft gravity refueling port cover that combines electrical connection and lightning protection functions, characterized in that, The system includes a fuel tank opening, an upper cover assembly, and a lower cover. The fuel tank opening is fixedly mounted on the fuel tank opening and is fixedly connected to the outer wall of the aircraft around its perimeter. The upper cover assembly includes a metal base and an insulating cover plate disposed inside the fuel tank opening. The metal base is located outside the fuel tank, and the insulating cover plate is located inside the fuel tank. The edges of the metal base and the insulating cover plate are sealed to the inner wall of the fuel tank opening. The lower cover is located inside the fuel tank and is connected to the bottom of the upper cover assembly. The fuel tank opening is made of a conductive material. A conductive element is disposed on the metal base and is in contact with the fuel tank opening.

2. The aircraft gravity refueling port cover with both electrical connection and lightning protection functions as described in claim 1, characterized in that, The metal base and the insulating cover plate are sealed to the inner wall of the cover seat at their four edges by sealing rings.

3. The aircraft gravity refueling port cover with both electrical connection and lightning protection functions as described in claim 1, characterized in that, The upper surface of the cap seat is flush with the upper surface of the metal base.

4. The aircraft gravity refueling port cover with both electrical connection and lightning protection functions as described in claim 1, characterized in that, The conductive element is an L-shaped elastic element. The horizontal end of the L-shaped elastic element is fixedly connected to the upper surface of the metal base by a metal screw, and the vertical end of the L-shaped elastic element is located between the cap seat and the metal base and is in contact with the cap seat.

5. The aircraft gravity refueling port cover with both electrical connection and lightning protection functions as described in claim 1, characterized in that, A handle is provided in the middle of the metal base, and a rotating shaft is provided inside the handle. The bottom of the rotating shaft is fixedly connected to the lower cover.

6. The aircraft gravity refueling port cover with both electrical connection and lightning protection functions as described in claim 5, characterized in that, Both the handle and the pivot are made of conductive materials.

7. The aircraft gravity refueling port cover with both electrical connection and lightning protection functions as described in claim 5, characterized in that, The lower cover is made of a high dielectric strength material.

8. The aircraft gravity refueling port cover with both electrical connection and lightning protection functions as described in any one of claims 4 to 7, characterized in that, The edge of the horizontal end of the L-shaped elastic element extends 0.1mm to 0.3mm beyond the inner wall of the cap seat.

Citation Information

Patent Citations

  • A quick -release flap for gravity oiling usefulness

    CN207644955U

  • Lightning protection type all-composite aircraft clamping covering cap structure

    CN210437373U

  • Novel gravity refueling quick-release covering cap

    CN216805845U

  • Gravity fuel filler cap and fuel tank

    CN220974543U

  • Lightning strike protection in aircraft

    US20120091269A1