Split type composite wing aircraft

Abstract

The invention belongs to the technical field of aircrafts, and particularly discloses a split type composite wing aircraft which comprises a fixed wing single aircraft, a four-rotor single aircraft and a separation and combination structure. The fixed-wing single aircraft and the four-rotor single aircraft are connected through a separation and combination mechanism; the fixed-wing single aircraft comprises a front pair of airfoils, a rear pair of airfoils, a tail vertical empennage, a tail horizontal pushing power device, a front double-body cabin, a rear double-body cabin and a cabin connecting rod; the four-rotor single aircraft comprises a rack, a motor and a propeller, and the propeller and the motor are mounted on the bottom surface of the rack; the separation and combination mechanism comprises an elastic connector, a separation pin, a separation seat, a positioning pin and a positioning seat, and the separation and combination mechanism can realize separation and combination of the fixed-wing single aircraft and the four-rotor aircraft through a control program. The aircraft takes off in the composite mode and can be separated into a fixed-wing single body and a four-rotor single body in the air, the fixed-wing single body and the four-rotor single body execute remote cruise or low-altitude maneuvering tasks respectively, and operation flexibility and environmental adaptability are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft, and in particular relates to a split-type composite-wing aircraft. Background Art

[0002] After decades of development, both fixed-wing and multi-rotor aircraft have received considerable attention and achieved extensive industrialization in the unmanned aerial vehicle (UAV) sector. Both aircraft possess distinct characteristics and differences in flight principles and performance. As a perennially popular configuration throughout a century of aviation development, fixed-wing aircraft boast high efficiency, heavy payloads, a wide flight envelope, and excellent controllability. However, traditional fixed-wing aircraft also have significant drawbacks: poor takeoff and landing performance, relying on runways or high-powered ground-based propulsion systems, making them incapable of flexible takeoff and landing anywhere. They are unable to hover or fly at low speeds, as slow speeds result in insufficient rudder control and a high risk of stalling. Their low turning efficiency, limited by their inherent dynamic constraints, restricts them to safe flight in open areas and makes them difficult to navigate complex obstacle environments. Fixed-wing aircraft struggle to descend to low altitudes in urban areas and in complex mountainous terrain. Ultimately, these three drawbacks stem from their dependence on speed for flight and control. Multi-rotor aircraft, on the other hand, offer nearly complementary advantages and disadvantages. Multirotor aircraft can hover and fly at low speeds. Combined with their smaller bodies, they can navigate obstacles. However, multirotor aircraft also have disadvantages such as low flight efficiency, short range, short hovering time, and slow flight speed. This significantly limits the carrying capacity and application range of quadrotors.

[0003] Traditional fixed-wing and multi-rotor aircraft lack sufficient comprehensive performance, which reduces their mission capabilities. However, the complementary advantages between the two have spurred the research and application of hybrid aircraft. Hybrid aircraft are primarily categorized as tiltrotor aircraft (tilt-rotor, tilt-wing), tail-seat aircraft, and lift-and-thrust aircraft (hereinafter referred to as composite-wing aircraft). All three types of aircraft combine the vertical takeoff and landing capabilities of multi-rotor aircraft with the long flight endurance of fixed-wing aircraft. Depending on their operating principles, these three types of aircraft have distinct advantages and disadvantages. Tiltrotor aircraft utilize a single powertrain for both rotor and fixed-wing modes, reducing waste weight and improving flight efficiency. However, the disadvantage is the difficulty in designing a powertrain that meets the requirements of multi-mode operation. The nonlinear characteristics during tilt-and-thrust transitions are significant, making control system design difficult and leading to a high failure rate. Composite-wing aircraft utilize separate powertrains for vertical and fixed-wing modes, reducing powertrain design complexity and improving flight safety. However, the drawback is that the dual powertrains of traditional composite-wing aircraft create significant waste weight and reduce flight efficiency. Tail-seat aircraft utilize a lift-and-thrust integrated fan at the tail, resulting in a simple structure and low weight. However, tail-seat aircraft lack vertical modal stability and wind resistance. Due to the presence of large fixed-wing surfaces, the mission capabilities of traditional hybrid-layout aircraft in helicopter mode are significantly limited: first, the drag and damping torque generated by the fixed-wing surfaces reduce the aircraft's maneuverability; second, the fixed-wing surfaces significantly reduce the hybrid-layout aircraft's wind resistance; and finally, the large size of the aircraft due to the fixed-wing surfaces impairs its ability to overcome obstacles, making it difficult to survive in complex obstacle environments such as jungles and cities. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention designs a split-type composite wing aircraft, which combines the long flight time of fixed wings and the vertical take-off and landing capability of quadrotors. The aircraft takes off in a composite mode and can be separated into a fixed-wing single body and a quadrotor single body in the air, each performing long-range cruise or low-altitude maneuvering missions, thereby improving operational flexibility and environmental adaptability.

[0005] A split composite wing aircraft of the present invention comprises a fixed-wing monocoque aircraft, a quadrotor monocoque aircraft and a separate assembly structure;

[0006] The fixed-wing single-body aircraft and the quadrotor single-body aircraft are connected via a separation and combination mechanism;

[0007] The fixed-wing monobody aircraft comprises two pairs of front and rear wing surfaces, a vertical tail at the tail, a horizontal propulsion power unit at the tail, front and rear catamaran cabins, and a cabin connecting rod;

[0008] The four-rotor single-body aircraft comprises a frame, a motor, and a propeller, wherein the propeller and the motor are mounted on the bottom surface of the frame;

[0009] The separation and combination mechanism includes an elastic connector, which realizes data communication between the two monomers through elastic contacts; a separation pin and a separation seat, which are driven by a servo to complete locking or unlocking; a positioning pin and a positioning seat, which limit the relative movement of the two monomers in non-vertical directions. The separation and combination mechanism can realize the separation and combination of the fixed-wing single-unit aircraft and the quadrotor aircraft through a control program.

[0010] The fixed-wing monocoque aircraft adopts a tandem wing layout, wherein the front wing area is smaller than the rear wing and the installation angle is larger, and the front and rear wingtips are provided with wingtip ailerons with variable camber angles.

[0011] The fixed-wing single-body aircraft adopts a double-body cabin layout, the cabins are connected by a cabin connecting rod, and the four-rotor single-body aircraft is arranged between the front and rear cabins; the front cabin is arranged with batteries and payload equipment, and the rear cabin is arranged with the control system of the entire aircraft.

[0012] The four-rotor single-body aircraft is also provided with a rudder driving mechanism, which includes a control rod connected to the rudder, and the rudder is arranged on the outer sections of the two pairs of wings.

[0013] A flight control assembly is provided in the middle of the frame of the quadrotor single-body aircraft, and an electric speed controller and a power supply assembly are connected in sequence below the flight control assembly. A landing gear is also connected downward on the frame corresponding to the quadrotor.

[0014] The flight control assembly is also equipped with a flight control shock absorbing bracket.

[0015] The centers of gravity of the quadrotor monocoque aircraft and the fixed-wing monocoque aircraft overlap in a top-view projection plane.

[0016] The beneficial effects of the present invention are:

[0017] Compared with the existing technology, the present invention significantly improves the range of the quadrotor aircraft and broadens the flight range by using a fixed-wing to carry the quadrotor aircraft; then the composite wing aircraft is separated into a clean-configuration fixed-wing single-body aircraft and a quadrotor single-body aircraft through a detachable mechanism, which makes up for the shortcoming of insufficient maneuverability of the composite wing aircraft in rotor mode; it can be separated into fixed-wing and quadrotor single-body aircraft in the air, each of which performs long-range cruising or low-altitude maneuvering tasks, significantly improving operational flexibility and environmental adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments.

[0019] Figure 1 Schematic diagram of the overall structure of the composite wing aircraft in the embodiment.

[0020] Figure 2 Schematic diagram of the structure of the four-rotor single-body aircraft in the embodiment.

[0021] Figure 3 It is a schematic diagram of the partial structure of the quadrotor single body aircraft from the side in the embodiment.

[0022] Figure 4 2 is a schematic diagram of the structure of the separation and assembly mechanism of the composite wing aircraft in the embodiment.

[0023] Figure 5 Schematic diagram of the structure of the control surface drive mechanism of the fixed-wing monocoque aircraft in the embodiment.

[0024] Figure 6 Schematic diagram of the structure of the separately controlled shock absorbing bracket of the quadrotor monocoque aircraft in the embodiment.

[0025] In the accompanying drawings, the structural names represented by the reference numerals are:

[0026] 10-fixed-wing monocoque aircraft, 11-cabin connecting rod, 12-front wing, 13-vertical tail, 14-rear wing, 15-horizontal propulsion power unit, 20-quadrotor monocoque aircraft, 21-frame, 22-motor, 23-propeller, 24-flight control assembly, 25-power supply assembly, 26-landing gear, 27-electric adjustment, 30-separation assembly mechanism, 31-elastic connector, 32-locating pin, 33-cover, 34-connecting rod, 35-rudder arm, 36-housing, 37-separation seat, 38-separation pin, 39-locating seat, 40-rudder surface drive mechanism, 41-rudder, 42-control rod, 50-flight control shock absorber bracket. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. In addition, the technical features involved in the various embodiments described below can be combined with each other as long as they do not conflict with each other.

[0028] Example 1

[0029] In order to combine the long flight time and high efficiency of fixed-wing aircraft with the vertical take-off and landing, hovering and low-speed maneuvering capabilities of quadrotor aircraft, refer to Figures 1 to 6 As shown, in this embodiment, a split composite wing aircraft is proposed, comprising a fixed-wing monocoque aircraft 10, a quadrotor monocoque aircraft 20 and a separate assembly structure;

[0030] The fixed-wing monohull aircraft 10 comprises two pairs of front and rear wing surfaces, a vertical tail 13 at the tail, a horizontal propulsion power unit 15 at the tail, front and rear catamaran cabins, and a cabin connecting rod 11;

[0031] The fixed-wing monocoque aircraft 10 adopts a tandem wing layout, with the front wing 12 smaller than the rear wing 14. Specifically, the front wing 12 is positioned above the rear wing 14, forming a vertical tandem structure. This achieves excellent longitudinal balance and pitch stability. Furthermore, the front wing 12 is mounted at a larger angle, enabling it to generate adequate lift at relatively high angles of attack during flight while preventing it from causing significant turbulence on the rear wing 14. Relatively speaking, the rear wing 14 has a greater lift line slope to ensure stability in the pitch channel. This "smaller front, larger rear, higher front, lower rear" arrangement allows the aircraft's aerodynamic focus to be positioned behind the center of gravity, achieving longitudinal static stability throughout the aircraft's full flight envelope. This means that when encountering airflow disturbances or changes in angle of attack, the aircraft can automatically return to a balanced state, enhancing operational safety. Both the front and rear wings are equipped with variable-camber winglets. These winglets feature a geometry with a continuously varying spanwise camber angle (variable camber design). This effectively reduces the intensity of wingtip vortices and weakens the vortex structure generated by airflow leaking from the wing's underside to the upper surface, thereby reducing drag and improving lift-to-drag ratio. This design significantly optimizes aerodynamic efficiency, particularly under high-speed cruising or high-lift conditions.

[0032] To ensure the wings maintain excellent structural rigidity and load-bearing capacity during flight, a 3K carbon fiber circular tube is embedded within each of the front and rear wings 12 and 14, serving as a main beam. This beam runs span-wise and, through cross-connection with the internal rib structure, forms a high-rigidity, high-strength load-bearing framework, effectively resisting the bending stresses generated by lift and the structural loads during maneuvers. Furthermore, this beam design balances lightweighting with maintainability, making it a critical structural support element for tandem-wing aircraft to achieve high-performance flight.

[0033] The vertical tail 13 adopts a double vertical tail symmetrical layout, with a span of 160mm for each tail, a tip-to-root ratio of 0.83, and a wing area of 0.0352m 2The vertical tail 13 is tilted outward relative to the vertical axis of the nacelle, effectively reducing wake turbulence interference, improving yaw stability, and enhancing the aircraft's controllability in crosswinds or turns. The vertical tail 13 is connected to the nacelle cover structure via bayonet-fit screws, which are then secured by a reinforcement structure. This ensures that the aerodynamic loads generated by the vertical tail 13 during flight are stably transmitted to the main fuselage structure. The horizontal propulsion unit 15 provides horizontal thrust, ensuring efficient flight during the cruise phase of the aircraft. This arrangement not only effectively frees up space within the nose nacelle but also significantly reduces the aerodynamic interference of the propeller 23 slipstream on the front and rear wings 12, 14, helping to improve the aircraft's aerodynamic stability in multiple modes. Furthermore, to reduce the additional drag caused by the exposed rotor and enhance acceleration performance during transition phases, the present invention appropriately enhances the thrust redundancy of the horizontal propulsion unit 15, bringing the thrust-to-weight ratio of the fixed-wing monohull aircraft 10 to a design value close to 1 when fully loaded. After aerodynamic analysis and system matching calculations, the tail thrust motor 22 needs to provide a static thrust of no less than 2.5 kg under rated working conditions.

[0034] The tail thruster motor 22 uses a T-Motor 2808 brushless motor with a constant speed of 1300kV. It is equipped with a 7035 three-blade folding propeller and powered by a 6S lithium battery. When fully charged, this combination provides approximately 2.58kg of static thrust, meeting the power requirements of the aircraft in high-power flight conditions such as vertical-to-horizontal transitions, dives, and acceleration, ensuring excellent responsiveness and maneuverability in complex flight modes.

[0035] Fixed-wing monocoque aircraft 10 features a twin-hull design, with the front and rear cabins connected by a cabin connecting rod 11. The front cabin primarily houses batteries and payload equipment, such as electro-optical pods, reconnaissance equipment, or warheads; the rear cabin houses the aircraft's control system, including flight control hardware and data loggers.

[0036] The quadrotor monocopter 20 employs an "X"-shaped quadrotor layout and consists of a chassis 21, four motors 22, and corresponding propellers 23. The motors 22 and propellers 23 are mounted on the underside of the chassis 21. The motors 22's speed is controlled by electronic speed controllers 27, enabling the aircraft to take off and land vertically, hover, and perform low-speed maneuvers. A flight control unit 24 is located in the center of the chassis 21, responsible for attitude control, navigation, and mission management. The flight control unit 24 is connected in sequence to the electronic speed controllers 27 and power supply unit 25, providing stable power to the aircraft.

[0037] The frame 21 is connected to the landing gear 26 corresponding to the quadcopter downwards, which is used to support the stable parking of the aircraft on the ground. The flight control assembly 24 is also equipped with a flight control shock-absorbing bracket 50, which effectively reduces the impact of vibration on the flight control system during flight and improves flight stability.

[0038] The fixed-wing monobloc aircraft 10 and the quadcopter monobloc aircraft 20 are connected by a separation assembly mechanism 30; the separation assembly mechanism 30 includes an elastic connector, a positioning pin 32, a cover plate 33, a connecting rod 34, a rudder arm 35, a housing 36, a separation seat 37, a separation pin 38 and a positioning seat 39, and an elastic connector 31. The data communication between the two monomers is realized through elastic contacts to ensure that the information transmission between the two aircraft before and after separation is not affected; the separation pin 38 and the separation seat 37 are driven by the servo to complete locking or unlocking. In the assembled state, the separation pin 38 and the separation seat 37 are locked or unlocked. 8 is inserted into the separation seat 37 to securely fix the two aircraft; when separation is required, the servo drives the separation pin 38 to be pulled out to unlock; the positioning pin 32 and the positioning seat 39 are distributed on both sides of the quadrotor aircraft, and cooperate with the corresponding structure on the fixed-wing aircraft to limit the relative movement of the two monomers in the non-vertical direction, ensuring that the relative position of the two aircraft is stable at the moment of separation, facilitating their independent flight. The separation and combination mechanism 30 can realize the separation and combination of the fixed-wing monomer aircraft 10 and the quadrotor aircraft through the control program.

[0039] In terms of structural load-bearing, the release pin 38 primarily bears the shear force from the release seat 37. The pin body is constructed from high-strength alloy steel, offering excellent shear resistance. Because the drive mechanism only needs to overcome slight friction between the pin and the pinhole, the servo output torque requirement is relatively low, enabling the use of a small drive unit for stable control.

[0040] Fixed-wing monocoque aircraft 10 is also equipped with a control surface drive mechanism 40, which includes a control rod 42 connected to control surfaces 41. Control surfaces 41 are arranged on the outer sections of the two pairs of wings. Control rods 42 connect control surfaces 41, which are arranged on the outer sections of the wings, to enhance flight stability or achieve specific flight maneuvers.

[0041] The centers of gravity of the quadrotor monocoque aircraft 20 and the fixed-wing monocoque aircraft 10 overlap in the top projection plane, which optimizes the aircraft's control and stability, allowing the aircraft to maintain good flight stability in both the combined mode and the separated mode.

[0042] Flight mode and operation process:

[0043] Takeoff phase:

[0044] The aircraft takes off in a compound mode, using the vertical rotor power of the quadcopter to achieve vertical takeoff and landing.

[0045] Transition phase:

[0046] As the flight speed increases, the fixed-wing horizontal propulsion power unit 15 starts to work, and the rotor power gradually decreases until the aircraft reaches the cruising speed.

[0047] Level flight phase:

[0048] During the level flight phase, the rotors of the quadcopter remain stationary, and only the horizontal propulsion power unit 15 of the fixed wing provides flight power. The control system remains powered on to monitor the flight status.

[0049] Separation and independent flight:

[0050] When the aircraft arrives at the work site or needs to perform a specific task, the separation mechanism can be used to separate the fixed-wing single-body aircraft 10 and the quadcopter single-body aircraft 20. After separation, both aircraft can fly or land independently and perform long-range cruising or low-altitude maneuvering tasks.

[0051] The present invention significantly improves the range and flight range of the quadrotor aircraft by using a fixed-wing aircraft to carry the quadrotor aircraft; the composite wing aircraft is separated into a clean-configuration fixed-wing single-body aircraft 10 and a quadrotor single-body aircraft 20 through a detachable mechanism, thereby compensating for the lack of maneuverability of the composite wing aircraft in rotor mode; the composite wing aircraft can be separated into fixed-wing and quadrotor single-body aircraft in the air, each of which can perform long-range cruising or low-altitude maneuvering tasks, significantly improving operational flexibility and environmental adaptability.

[0052] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. The preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification.

Claims

1. A split-type composite wing aircraft, characterized in that: It comprises a fixed-wing monobloc aircraft (10), a quad-rotor monobloc aircraft (20) and a separate assembly structure; The fixed-wing monohull aircraft (10) and the quadrotor monohull aircraft (20) are connected via a separation and combination mechanism (30); The fixed-wing monobody aircraft (10) comprises two pairs of front and rear wing surfaces, a vertical tail (13) at the tail, a horizontal propulsion power unit (15) at the tail, front and rear catamaran cabins, and a cabin connecting rod (11); The four-rotor single-body aircraft (20) comprises a frame (21), a motor (22), and a propeller (23), wherein the propeller (23) and the motor (22) are mounted on the bottom surface of the frame (21); The separation and combination mechanism (30) includes an elastic connector (31) for realizing data communication between the two monomers through elastic contacts; a separation pin (38) and a separation seat (37) driven by a steering gear to complete locking or unlocking; and a positioning pin (32) and a positioning seat (39) for limiting the relative movement of the two monomers in a non-vertical direction. The separation and combination mechanism (30) can realize the separation and combination of the fixed-wing monomer aircraft (10) and the quadrotor aircraft through a control program.

2. The split-type composite wing aircraft according to claim 1, characterized in that: The fixed-wing monobody aircraft (10) adopts a tandem wing layout, the front wing (12) has a smaller area than the rear wing (14) and a larger installation angle, and the tips of the front and rear wings (14) are provided with winglets with variable camber angles.

3. The split-type composite wing aircraft according to claim 1, characterized in that: The fixed-wing monobody aircraft (10) adopts a double-body cabin arrangement, the cabins are connected by a cabin connecting rod (11), and the quadrotor monobody aircraft (20) is arranged between the front and rear cabins; the front cabin is arranged with batteries and payload equipment, and the rear cabin is arranged with a control system for the entire aircraft.

4. The split-type composite wing aircraft according to claim 1, characterized in that: The quadrotor monocoque aircraft (20) is also provided with a control surface (41) driving mechanism, which includes a control rod (42) connected to the control surface (41). The control surface (41) is arranged on the outer sections of the two pairs of wings.

5. The split-type composite wing aircraft according to claim 1, characterized in that: A flight control assembly (24) is arranged in the middle of a frame (21) of the quadrotor monocoque aircraft (20), and an electric regulator (27) and a power supply assembly (25) are sequentially connected to the flight control assembly (24). A landing gear (26) is also connected downwardly on the frame (21) corresponding to the quadrotor.

6. The split-type composite wing aircraft according to claim 5, characterized in that: The flight control assembly (24) is also equipped with a flight control shock absorbing bracket (50).

7. The split-type composite wing aircraft according to claim 1, characterized in that: The centers of gravity of the quadrotor monocoque aircraft (20) and the fixed-wing monocoque aircraft (10) overlap in a top-view projection plane.

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