A metal-composite hybrid fuselage structure

Abstract

A metal-composite hybrid fuselage structure comprises a metal skeleton structure and a composite exterior structure embedded in the metal skeleton structure. Based on the structural stress characteristics of the fuselage of a new basic trainer aircraft, the main load-bearing structure adopts a metal skeleton structure, and the non-main load-bearing fuselage exterior adopts a full-composite structure. Different composite structures are adopted according to the stress magnitude and function of each part to reduce the weight of the fuselage structure, reduce riveting assembly, and improve the surface quality of the fuselage. On the basis of achieving the requirements of lightweight aircraft structure, the structural strength and safety of the composite fuselage are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft structures, and in particular to a metal-composite hybrid fuselage structure. Background Art

[0002] Due to the demand for lightweight aircraft structures and the exceptional strength and stiffness of advanced, high-performance composite materials, along with advances in materials and manufacturing processes, the use of composite materials in aircraft structures is becoming increasingly common. In the development of new lightweight, low-speed aircraft, while meeting structural weight, strength, and stiffness requirements, it is necessary to consider different composite and metal options. This involves conducting a comparative analysis of multiple fuselage structural options, and ultimately determining the fuselage structural design after comprehensively weighing all requirements. Patent CN112550658B discloses a high-performance, high-strength tandem composite fuselage structure to address the issues of heavy fuselage structure that impacts flight, as well as the irrational internal distribution and low space utilization. Patent CN101941521B discloses a high-strength, high-safety composite light aircraft fuselage structure that maintains structural strength with a low weight, improving the structural strength and safety of the composite fuselage. However, due to the differences in overall appearance, structural form, and functional requirements of light, low-speed aircraft, as well as the varying locations where composite materials are applied, the technical solutions of these patents are not suitable for light, low-speed aircraft structures. Summary of the Invention

[0003] The technical problem solved by the present invention is to provide a metal-composite hybrid fuselage structure to solve the problems in the above-mentioned background technology.

[0004] The technical problem solved by the present invention is achieved by adopting the following technical solutions:

[0005] A metal-composite hybrid fuselage structure includes a metal skeleton structure and a composite outer structure embedded in the metal skeleton structure, the metal skeleton structure includes an engine docking frame, a fireproof baffle frame, a front fuselage upper beam, a cross beam, a front and rear fuselage separation frame, a rear fuselage upper beam, a horizontal tail docking frame, a vertical tail docking frame, a rear fuselage lower beam, a common frame, a wing docking frame, a cockpit floor, a front fuselage lower beam and a wheel well side wall; wherein the front fuselage upper beam and the rear fuselage upper beam are fixedly connected, and the front fuselage lower beam and the rear fuselage lower beam are fixedly connected to form a metal skeleton, and the metal The engine docking frame is installed at the front end of the frame, the horizontal tail docking frame is installed at the rear end of the metal frame, and the front and rear fuselage separation frames are installed on the metal frame at the connection between the front fuselage upper beam and the rear fuselage upper beam; at the same time, a crossbeam is installed on the upper part of the metal frame located between the engine docking frame and the front and rear fuselage separation frames; the wheel well side walls, cockpit floor, wing docking frame and ordinary frame are installed on the lower part of the metal frame located between the engine docking frame and the front and rear fuselage separation frames; the fireproof partition frame is installed above the wheel well side walls; the vertical tail docking frame is installed on the metal frame located at the end of the horizontal tail docking frame;

[0006] The composite external structure includes an engine lower cover, an engine upper cover, a front fuselage wall panel, a cockpit wall panel, a rear fuselage upper wall panel, a vertical tail fairing foreskin, a tail vertebra, a ventral fin, a rear fuselage aperture, a rear fuselage lower wall panel, a cockpit lower aperture cover, a rear fuselage middle wall panel, a front fuselage aperture cover and a front fuselage lower wall panel. The engine lower cover and the engine upper cover are embedded in the engine docking frame, the front fuselage upper wall panel, the front fuselage aperture cover, the front fuselage lower wall panel, the cockpit wall panel and the cockpit lower aperture cover are connected as a whole and embedded in the metal frame located between the engine docking frame and the front and rear fuselage separation frames, the rear fuselage upper wall panel, the vertical tail fairing foreskin, the ventral fin, the rear fuselage aperture cover and the rear fuselage lower wall panel are connected as a whole and embedded in the metal frame provided with a horizontal tail docking frame end, and the tail vertebra is embedded in the horizontal tail docking frame.

[0007] In the present invention, the engine docking frame, the fireproof bulkhead frame, the front and rear fuselage separation frames, the horizontal tail docking frame, the vertical tail docking frame and the wing docking frame are reinforcement frames for enhancing the strength of the metal frame.

[0008] In the present invention, docking joints are respectively provided on the engine docking frame, horizontal tail docking frame, vertical tail docking frame and wing docking frame to meet the installation requirements of the engine, wing, vertical tail and horizontal tail; a front landing gear installation joint is arranged on the side wall of the wheel bay.

[0009] In the present invention, the fireproof partition frame is formed by riveting stainless steel plates and machined aluminum alloy frame edges, and the remaining metal frames are machine-formed from aluminum alloy pre-stretched plates. After each metal frame is positioned by an assembly jig, it is fixed by mechanical connections such as riveting and screwing.

[0010] In the present invention, seat mounting joints are arranged on the crossbeam. Except for the wing docking joint which adopts a single-ear joint, the other joints adopt double-ear joints. The seat mounting joints are arranged symmetrically.

[0011] In the present invention, the engine lower cover, engine upper cover, rear fuselage cover, cockpit lower cover, and front fuselage cover are fiberglass foam sandwich structures, and the vertical tail fairing skin, ventral fin, and tail vertebrae are formed by laying out glass cloth prepreg; the cockpit wall panel is used for sealing the cockpit section. In order to increase the structural rigidity and meet the cockpit pressurization requirements, the cockpit wall panel is a whole-piece hat-shaped reinforced structure, including a skin and hat-shaped ribs, and the hat-shaped ribs are glued to the skin.

[0012] In the present invention, the front fuselage upper wall panel, the rear fuselage upper wall panel, the rear fuselage lower wall panel and the front fuselage middle wall panel are all integral laminated reinforced structures, consisting of a skin + L-shaped ribs, the L-shaped ribs are arranged circumferentially on the skin, the skin and the L-shaped ribs are respectively paved and formed by epoxy resin carbon fiber unidirectional tape prepreg and then glued together for a secondary forming; a transparent glass observation window is provided on the front fuselage lower wall panel for observing the status of the fuel shut-off valve, the transparent glass observation window comprises a skin, a glass window and a mouth frame, the mouth frame is formed of aluminum alloy sheet metal, the glass window is cut from aviation organic glass, and the glass window is compacted between the skin and the mouth frame by installing rivets around the mouth frame.

[0013] In the present invention, a layer of copper mesh is paved on the surface of the composite material structure. The copper mesh serves as a guide medium to prevent damage to the composite material structure caused by lightning, thereby achieving the effect of lightning protection.

[0014] Beneficial effects: The present invention is based on the stress characteristics of the fuselage structure of the new basic trainer aircraft. The main load-bearing structure adopts a metal skeleton structure, and the non-main load-bearing fuselage shape adopts a full composite structure. Different composite structures are used according to the stress size and function of each part to reduce the weight of the fuselage structure, reduce riveting assembly, and improve the surface quality of the fuselage; on the basis of achieving the requirements of lightweight aircraft structure, the structural strength and safety of the composite fuselage are effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of a preferred embodiment of the present invention.

[0016] Figure 2 Schematic diagram of the metal skeleton structure in a preferred embodiment of the present invention.

[0017] Figure 3 Schematic diagram of the composite material structure in a preferred embodiment of the present invention.

[0018] Figure 4 Schematic diagram of the laminated reinforcement structure in the composite material outer structure in a preferred embodiment of the present invention.

[0019] Figure 5 Schematic diagram of the composite material exterior structure cabin wall panel structure in a preferred embodiment of the present invention.

[0020] Figure 6 Schematic diagram of the transparent glass observation window structure in the composite material appearance structure in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0022] See also Figures 1 to 6A metal-composite hybrid fuselage structure includes a metal skeleton structure and a composite outer structure embedded in the metal skeleton structure, the metal skeleton structure includes an engine docking frame 1, a fireproof baffle frame 3, a front fuselage upper beam 5, a crossbeam 7, a front and rear fuselage separation frame 9, a rear fuselage upper beam 11, a horizontal tail docking frame 13, a vertical tail docking frame 15, a rear fuselage lower beam 17, a common frame 19, a wing docking frame 21, a cockpit floor 23, a front fuselage lower beam 25 and a wheel well side wall 27; wherein the front fuselage upper beam 5 is fixedly connected to the rear fuselage upper beam 11, and the front fuselage lower beam 25 is fixedly connected to the rear fuselage lower beam 17 to form a metal skeleton, and The front end of the metal frame is mounted with an engine docking frame 1, the rear end is mounted with a horizontal tail docking frame 13, and the front and rear fuselage separation frames 9 are mounted on the metal frame at the connection between the front fuselage upper beam 5 and the rear fuselage upper beam 11. A crossbeam 7 is mounted on the upper portion of the metal frame between the engine docking frame 1 and the front and rear fuselage separation frames 9. The lower portion of the metal frame between the engine docking frame 1 and the front and rear fuselage separation frames 9 is mounted with wheel well sidewalls 27, a cockpit floor 23, a wing docking frame 21, and a conventional frame 19. A fireproof bulkhead 3 is mounted above the wheel well sidewalls 27. The vertical tail docking frame 15 is mounted on the metal frame at the end of the horizontal tail docking frame 13.

[0023] The composite outer structure includes an engine lower cover 2, an engine upper cover 4, a front fuselage upper wall panel 6, a cockpit wall panel 8, a rear fuselage upper wall panel 10, a vertical tail fairing foreskin 12, a tail cone 14, a ventral fin 16, a rear fuselage opening cover 18, a rear fuselage lower wall panel 20, a cockpit lower opening cover 22, a front fuselage middle wall panel 24, a front fuselage opening cover 26 and a front fuselage lower wall panel 28. The engine lower cover 2 and the engine upper cover 4 are embedded in the engine docking frame 1, and the front fuselage upper wall panel 6, the front fuselage lower wall panel 22, the front fuselage middle wall panel 24, the front fuselage opening cover 26 and the front fuselage lower wall panel 28. The wall panel 28, the front fuselage cover 26, the front fuselage middle wall panel 24, the cockpit wall panel 8, and the cockpit lower cover 22 are connected as a whole and embedded in the metal frame located between the engine docking frame 1 and the front and rear fuselage separation frames 9. The rear fuselage upper wall panel 10, the vertical tail fairing foreskin 12, the ventral fin 16, the rear fuselage cover 18, and the rear fuselage lower wall panel 20 are connected as a whole and embedded in the metal frame provided with the horizontal tail docking frame 13 end, and the tail vertebrae 14 are embedded in the horizontal tail docking frame 13.

[0024] In this embodiment, the engine docking frame 1, the fireproof baffle frame 3, the front and rear fuselage separation frames 9, the horizontal tail docking frame 13, the vertical tail docking frame 15 and the wing docking frame 21 are reinforcement frames for strengthening the metal frame.

[0025] In this embodiment, the fireproof frame 3 is used to prevent the engine from catching fire and the flame from entering the cockpit and affecting the safety of the pilot; in order to meet the installation requirements of the engine, wings, vertical tail and horizontal tail, docking joints are respectively provided on the engine docking frame 1, the horizontal tail docking frame 13, the vertical tail docking frame 15 and the wing docking frame 21; and a front landing gear mounting joint is arranged on the wheel bay side wall 27.

[0026] In this embodiment, the fireproof partition frame 3 is formed by riveting a stainless steel plate and a machined aluminum alloy frame edge, and the remaining metal frames are machine-formed from aluminum alloy pre-stretched plates. After each metal frame is positioned by an assembly jig, it is fixed by mechanical connections such as riveting and screwing.

[0027] In this embodiment, seat mounting joints are arranged on the crossbeam 7. Except for the wing docking joint which adopts a single-ear joint, the other joints adopt double-ear joints. The seat mounting joints are arranged symmetrically.

[0028] In this embodiment, the engine lower cover 2, the engine upper cover 4, the rear fuselage cover 18, the cockpit lower cover 22, and the front fuselage cover 26 are made of a fiberglass foam sandwich structure. The vertical tail fairing cover 12, the ventral fin 16, and the tail cone 14 are formed by laying up glass cloth prepreg. The cockpit wall panel 8 is used for cockpit section sealing. To increase structural rigidity and meet cockpit pressurization requirements, the cockpit wall panel 8 adopts a monolithic hat-shaped reinforced structure, including a skin 81 and a hat-shaped rib 82. The hat-shaped rib 82 is glued to the skin 81 as a whole. Figure 5 As shown;

[0029] The front fuselage upper wall panel 6, the rear fuselage upper wall panel 10, the rear fuselage lower wall panel 20 and the front fuselage middle wall panel 24 adopt a monolithic laminated reinforced structure, consisting of skin + L-shaped ribs, such as Figure 4 As shown, P is an L-shaped rib, which is arranged in a circumferential direction on the skin. The skin and the L-shaped rib are respectively laid out and formed by epoxy resin carbon fiber unidirectional tape prepreg and then glued together for a secondary forming process. A transparent glass observation window is provided on the front fuselage lower wall panel 28 for observing the status of the fuel shut-off valve. The transparent glass observation window includes a skin 281, a glass window 282 and a frame 283. The frame 283 is formed of aluminum alloy sheet metal, and the glass window 282 is cut from aviation organic glass. Rivets are installed around the frame 283 to press the glass window 282 between the skin 281 and the frame 283. Figure 6 As shown in the figure, in order to avoid damage to the composite structure caused by lightning, a layer of copper mesh is laid on the surface of the composite structure as a guide medium to achieve the effect of lightning protection.

[0030] In this embodiment, the engine lower cover 2 and the engine upper cover 4 are connected to the fuselage structure by screws, support plate nuts and hook-shaped quick-release locks to realize the disassembly and assembly of the engine cover; the front fuselage cover 26 is connected to the fuselage structure by a KTCS quick-release lock, the cockpit lower cover 22 and the vertical tail fairing foreskin 12 are connected to the fuselage structure by screws and support plate nuts, and the rear fuselage cover 18 is connected to the fuselage structure by a button quick-release lock. To ensure the sealing of the cockpit and meet the cockpit airtightness requirements, the cockpit wall panel 8 is riveted to the metal frame by gluing, and the front fuselage upper wall panel 6, the rear fuselage upper wall panel 10, the rear fuselage lower wall panel 20, the front fuselage middle wall panel 24, the tail cone 14 and the ventral fin 16 are riveted to the fuselage structure by rivets, completing the installation of the composite outer structure on the fuselage.

[0031] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A metal-composite hybrid fuselage structure, comprising a metal skeleton structure and a composite outer structure embedded in the metal skeleton structure, characterized in that: The metal frame structure includes an engine docking frame, a fireproof bulkhead frame, a front fuselage upper beam, a crossbeam, a front and rear fuselage separation frame, a rear fuselage upper beam, a horizontal tail docking frame, a vertical tail docking frame, a rear fuselage lower beam, a common frame, a wing docking frame, a cockpit floor, a front fuselage lower beam and a wheel well side wall; wherein, the front fuselage upper beam and the rear fuselage upper beam are fixedly connected, and the front fuselage lower beam and the rear fuselage lower beam are fixedly connected to form a metal frame, and the engine docking frame is installed at the front end of the metal frame, the horizontal tail docking frame is installed at the rear end of the metal frame, and the front and rear fuselage separation frames are arranged on the metal frame at the connection between the front fuselage upper beam and the rear fuselage upper beam; at the same time, a crossbeam is installed on the upper part of the metal frame between the engine docking frame and the front and rear fuselage separation frames, and the wheel well side wall, the cockpit floor, the wing docking frame and the common frame are arranged on the lower part of the metal frame between the engine docking frame and the front and rear fuselage separation frames, and the fireproof bulkhead frame is arranged above the wheel well side wall; the vertical tail docking frame is installed on the metal frame at the end of the horizontal tail docking frame; The composite external structure includes an engine lower cover, an engine upper cover, a front fuselage wall panel, a cockpit wall panel, a rear fuselage upper wall panel, a vertical tail fairing foreskin, a tail vertebra, a ventral fin, a rear fuselage aperture, a rear fuselage lower wall panel, a cockpit lower aperture cover, a rear fuselage middle wall panel, a front fuselage aperture cover and a front fuselage lower wall panel. The engine lower cover and the engine upper cover are embedded in the engine docking frame, the front fuselage upper wall panel, the front fuselage aperture cover, the front fuselage lower wall panel, the cockpit wall panel and the cockpit lower aperture cover are connected as a whole and embedded in the metal frame located between the engine docking frame and the front and rear fuselage separation frames, the rear fuselage upper wall panel, the vertical tail fairing foreskin, the ventral fin, the rear fuselage aperture cover and the rear fuselage lower wall panel are connected as a whole and embedded in the metal frame provided with a horizontal tail docking frame end, and the tail vertebra is embedded in the horizontal tail docking frame.

2. The metal-composite hybrid fuselage structure according to claim 1, characterized in that: The engine docking frame, the horizontal tail docking frame, the vertical tail docking frame and the wing docking frame are respectively provided with docking joints.

3. The metal-composite hybrid fuselage structure according to claim 1, characterized in that: The fireproof partition frame is made of stainless steel plate and machined aluminum alloy frame edge riveted together.

4. The metal-composite hybrid fuselage structure according to claim 1, characterized in that: The engine lower cover, engine upper cover, rear fuselage cover, cockpit lower cover and front fuselage cover are fiberglass foam sandwich structures.

5. The metal-composite hybrid fuselage structure according to claim 1, characterized in that: The cabin wall panel is a one-piece hat-shaped reinforced structure, including a skin and hat-shaped ribs, and the hat-shaped ribs are glued to the skin.

6. The metal-composite hybrid fuselage structure according to claim 1, characterized in that: The vertical tail fairing skin, ventral fin and tail vertebrae are formed by laying out glass cloth prepreg.

7. The metal-composite hybrid fuselage structure according to claim 1, characterized in that: The front fuselage upper wall panel, rear fuselage upper wall panel, rear fuselage lower wall panel and front fuselage middle wall panel are all integral laminated reinforced structures. The integral laminated reinforced structure consists of skin + L-shaped ribs. The L-shaped ribs are arranged circumferentially on the skin. The skin and L-shaped ribs are separately laid out with epoxy resin carbon fiber unidirectional tape prepreg and then glued together for a secondary forming process.

8. The metal-composite hybrid fuselage structure according to claim 1, characterized in that: A transparent glass observation window is provided on the lower wall panel of the front fuselage.

9. The metal-composite hybrid fuselage structure according to claim 1, characterized in that: The surface of the composite structure is covered with a layer of copper mesh.

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