A large-load transport UAV based on a ducted fan

Abstract

The present invention provides a large-load transport unmanned aerial vehicle based on ducted fans, which includes a fuselage, left and right wings, a V-shaped tail, main ducted fans arranged at the front and rear of the fuselage, and auxiliary ducted fans arranged at the fuselage-wing fusion part on the left and right; the fuselage adopts a lifting body structure, the belly of the fuselage is flat, and the back is a flat-convex shape. The lower part of the front end of the first main ducted fan of the fuselage is designed as an arc-shaped concave surface, and the rear end is tangent to the lower edge of the first main ducted fan; the main ducted fans and the auxiliary ducted fans are both horizontally arranged in the ducted fans of the aircraft body, and grids matching the aerodynamic shape of the unmanned aerial vehicle are provided at the upper and lower ends of the main ducted fans and the auxiliary ducted fans. This unmanned aerial vehicle improves the structural layout of traditional fixed-wing unmanned aerial vehicles, uses a lifting body fuselage to provide aerodynamic lift, and combines ducted fans to meet the requirements of vertical takeoff and landing, rapid cruising, and large load capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and particularly to a ducted vertical takeoff and landing fixed-wing unmanned aerial vehicle. Background Art

[0002] Traditional takeoff and landing drones with wheeled takeoff and landing are restricted by runways and are difficult to play their advantageous roles in mountainous areas, narrow sites, islands and other regions. Vertical takeoff and landing drones have become a hot topic in recent years because they do not require runways or can take off in a short distance. Compound-wing drones are difficult to achieve large payloads due to the influence of rotors. Unmanned helicopters have large payload capabilities, but their cruising speeds are relatively small and it is difficult to meet rapid emergency requirements. To achieve vertical takeoff and landing of drones, several propulsion concepts have been successively applied to the research and development of drones, including direct lift engines, vector nozzle turbojet engines, thrust augmentation inlets and other solutions. However, due to the too high technical difficulty, only a few drones are currently in use. Summary of the Invention

[0003] The purpose of the present invention is to provide a large payload transport drone based on ducted fans. Through optimized layout, the drone has both vertical takeoff and landing and wheeled takeoff and landing capabilities, has excellent battlefield adaptability, and meets the requirements of large payload and rapid cruise transport tasks in mountainous areas, islands and narrow sites and other regions.

[0004] The technical solution adopted by the present invention to achieve the above purpose is as follows:

[0005] A large payload transport drone based on ducted fans, comprising a fuselage, left and right wings, a V-shaped tail, main ducts arranged at the front and rear of the fuselage, and auxiliary ducts arranged at the fuselage-wing fusion; the fuselage adopts a lifting body structure, the abdomen of the fuselage is flat and the back is a convex-concave shape, and the lower part of the front end of the first main duct of the fuselage is designed as an arc-shaped concave surface, and the rear end is tangent to the lower edge of the first main duct; the main duct fans and the auxiliary duct fans are both horizontally arranged in the body ducts, and grille matching the aerodynamic shape of the drone is provided at the upper and lower ends of the main ducts and the auxiliary ducts.

[0006] Furthermore, the maximum lateral dimension of the drone fuselage is 1 / 3 to 2 / 5 of the longitudinal dimension, the wingspan is 3 to 3.5 times the maximum lateral dimension of the fuselage, the centers of the first and second main ducts are respectively at 1 / 3 of the distance from the front end of the fuselage and 5 / 6 of the distance from the front end of the fuselage, the center of the auxiliary duct is located at the fuselage-wing fusion and is at 1 / 2 to 3 / 5 of the longitudinal dimension of the fuselage, the V-shaped tail is located at the rear of the second main duct and the front end of the V-shaped tail corresponds to the center of the second main duct; the diameter of the auxiliary duct fan is 50 to 60% of the diameter of the main duct fan.

[0007] Furthermore, the main duct and the auxiliary duct penetrate vertically up and down. The duct wall is connected to the fuselage and the wing skin. After the duct grille is closed, it will be completely sealed up and down. The main duct wall is connected to the fuselage beam. The front and rear ends of the auxiliary duct wall are connected to the wing beam, and one side of the auxiliary duct wall is connected to the fuselage frame. The duct fan is installed in the duct through a bracket.

[0008] Furthermore, the grille is of the louver type. Each group of grilles is designed with a linkage structure. The grille is connected to the rack. The rack is arranged at the center position at one end of the duct and is perpendicular to the grille direction. Both ends of the rack are inserted through the duct wall. The servo is arranged at one end of the rack and fixed on the outer wall of the duct. The servo is connected to the gear arranged on the rack through a linkage mechanism. By controlling the rotation of the servo to drive the gear to rotate, the movement of the rack is realized, and the deflection and closing of the grille are completed.

[0009] Furthermore, landing gears and modular cargo holds are arranged on the belly of the fuselage.

[0010] Furthermore, the modular cargo hold is arranged between the belly of the fuselage and the front and rear main ducts. The fuselage is correspondingly provided with modular installation interfaces. The modular cargo hold is provided with fixed lugs. Connecting lugs and electric push rods are arranged at the corresponding positions on the fuselage. The electric push rod extends out to fix the connecting lug on the fuselage and the fixed lug on the cargo hold.

[0011] Furthermore, positioning and guiding grooves are also arranged on the front and rear side walls of the modular cargo hold, which cooperate with the guiding blocks on the fuselage. The fixed lugs and the connecting lugs are provided with electric push rod insertion holes with a certain taper at the front end. The front end of the electric push rod also has a certain taper.

[0012] Furthermore, the bottom configuration of the modular cargo hold is consistent with the outer shape of the belly skin of the fuselage. The internal structure and functions of the modular cargo hold are adaptively modified according to different mission requirements.

[0013] Furthermore, the landing gear adopts a four-point landing gear, which is symmetrically arranged left and right between the cargo hold and the main duct. The front two landing gears can be retracted backward into the fuselage interior, and the rear two landing gears can be retracted forward into the fuselage interior.

[0014] Furthermore, flaps and ailerons are symmetrically arranged on the left and right wings, and left and right tail fin rudders are symmetrically arranged on the V-shaped tail fin. A propeller is arranged at the front end of the nose. The main duct fan is powered by a turboshaft engine, the auxiliary duct fan is powered by an electric motor, the propeller is powered by a turboshaft engine, and the power of the engine and the electric motor is transmitted through a shaft and cooperates with a clutch to be transmitted to the duct fan or the propeller.

[0015] The beneficial effects of the present invention compared with the prior art:

[0016] (1) The aerodynamic layout of the large-load transport UAV based on ducted fans in the present invention breaks through the traditional aerodynamic layout types of fixed-wing UAVs. The fuselage size is relatively large, the wing size is relatively small, and the fuselage structure is designed as a lifting body structure. During flight, the fuselage of the UAV can generate lift to support the fixed-wing UAV to cruise quickly in the air.

[0017] (2) Multiple lift ducted fans are arranged on the fuselage of the UAV, enabling the vertical takeoff and landing and hovering in the air of the UAV. The wheeled landing gear is arranged on the belly of the fuselage, enabling the short-distance large-load takeoff and landing and the ultra-large-load takeoff and landing on a normal runway of the UAV. The UAV has both vertical takeoff and landing and taxiing takeoff and landing capabilities, with strong environmental adaptability, and can meet the transportation task requirements in mountainous areas, islands, and narrow field areas.

[0018] (3) Traditional ducts are only used as channels for air flow to improve the working efficiency of the fan. In the present invention, the duct adopts an optimized design, and the overall structure can be used as a load-bearing member of the airframe structure, reducing the number of frames in the airframe structure, improving the structural strength, and reducing the overall structural weight of the UAV.

[0019] (4) The UAV adopts a modular cargo compartment and modular installation interface design, and different types of cargo compartments can be replaced according to different mission requirements to achieve a rapid conversion of different mission requirements.

[0020] (5) The conversion of the UAV mode is adjusted by the duct grille. The duct grille in the present invention is easier to control and has a fast conversion speed. Compared with the tilting of the entire duct, it is faster in terms of control and conversion speed. With a high mode conversion efficiency, the UAV can quickly achieve the mode conversion from vertical hovering to cruise flight.

[0021] This UAV can achieve vertical takeoff and landing, a high cruise speed, and a large load capacity. It has the same excellent effects in reducing the control difficulty and manufacturing cost of the UAV. The UAV has high flight efficiency and better battlefield adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The included drawings are used to provide a further understanding of the embodiments of the present invention, which form a part of the specification, are used to illustrate the embodiments of the present invention, and are used to explain the principles of the present invention together with the text description. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic structural diagram of the ducted fan grille of the large-load transport UAV based on ducted fans provided for the specific embodiment of the present invention;

[0024] Figure 2 ForFigure 1 Rear view of a large - load transport UAV

[0025] Figure 3 Schematic structural diagram of the closed duct grille of a large - load transport UAV based on ducted fans provided by a specific embodiment of the present invention

[0026] Figure 4 Schematic structural diagram of a modular cargo hold provided by a specific embodiment of the present invention

[0027] Figure 5 Schematic structural diagram of the fixing structure of a modular cargo hold provided by a specific embodiment of the present invention

[0028] Figure 6 Schematic structural diagram of the disassembly and assembly structure of a modular cargo hold provided by a specific embodiment of the present invention

[0029] Among them, the above - mentioned drawings include the following reference numerals:

[0030] 1, fuselage; 2, left wing; 3, right wing; 4, left flap rudder surface; 5, left aileron rudder surface; 6, right flap rudder surface; 7, right aileron rudder surface; 8, left tail; 9, right tail; 10, left tail rudder surface; 11, right tail rudder surface; 12, first main duct; 13, second main duct; 14, first auxiliary duct; 15, second auxiliary duct; 16, propeller; 17, landing gear; 18, cargo hold; 101, main structure of the cargo hold; 102, fixing lugs; 103, insertion holes; 104, guide grooves; 105, fuselage frame plates; 106, connecting lugs; 107, insertion holes for electric push rods; 108, electric push rods; 109, insertion rods. Detailed Description of the Invention

[0031] The following details the specific embodiments of the present invention. In the following description, for purposes of explanation rather than limitation, specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details.

[0032] It should be noted here that, in order to avoid obscuring the present invention with unnecessary details, only the equipment structures and / or processing steps closely related to the solution of the present invention are shown in the drawings, while other details less relevant to the present invention are omitted.

[0033] A large-load transport UAV based on ducted fans provided by the present invention includes a fuselage, left and right wings, a V-shaped tail, main ducted fans arranged at the front and rear of the fuselage, and auxiliary ducted fans arranged at the fuselage-wing fusion positions; the fuselage adopts a lifting body structure, the abdomen of the fuselage is flat, and the back is a flat-convex shape. The lower part of the front end of the first main ducted fan of the fuselage is an arc-shaped concave surface, and the rear end is tangent to the lower edge of the first main ducted fan; the main ducted fan and the auxiliary ducted fan are both horizontally arranged in the ducted of the aircraft body, and grids matching the aerodynamic shape of the UAV are provided at the upper and lower ends of the main ducted and the auxiliary ducted.

[0034] The main ducted fan of the UAV of the present invention is mainly used to provide the vertical lift required for the UAV during vertical takeoff and landing, so as to realize the vertical takeoff and landing of the UAV; the auxiliary ducted fan is mainly used to complete the attitude control of the UAV during the vertical takeoff and landing process. To meet the layout form of the main lift ducted, the fuselage is designed with a flat abdomen and a flat-convex back, and the lower part of the front end of the fuselage is designed to be concave. The whole fuselage is wide and large in volume, which can greatly increase the volume of the cargo hold and improve the transportation capacity of the UAV. At the same time, the lower part of the front end of the fuselage is designed as an arc-shaped concave surface, which has a significant effect on improving the lift of the UAV and reducing the flight resistance. This UAV improves the structural layout of the traditional fixed-wing UAV, adopts a lifting body fuselage to provide aerodynamic lift, and meets the requirements of fast cruising and large load.

[0035] The wing-fuselage connection adopts a wing-fuselage fusion design. The wing-fuselage fusion layout can increase the structural size of the connection to meet the installation and arrangement of the auxiliary ducted. The center of the auxiliary ducted fan is located at the wing-fuselage fusion position. Compared with being set on the wing, it can increase the size of the fan, provide better attitude control, and the horizontally installed auxiliary ducted fan can quickly and stably control the attitude of the UAV during vertical takeoff and landing. Compared with the tilting ducted, the installation structure form is simple, occupies less volume, and is easy to operate.

[0036] Furthermore, the maximum transverse dimension of the UAV fuselage is 1 / 3 - 2 / 5 of the longitudinal dimension, the wingspan is 3 - 3.5 times the maximum transverse dimension of the fuselage, the centers of the first and second main ducted fans are respectively at 1 / 3 and 5 / 6 of the distance from the front end of the fuselage, the center of the auxiliary ducted fan is located at the wing-fuselage fusion position and at 1 / 2 - 3 / 5 of the longitudinal dimension of the fuselage, and the V-shaped tail is located at the rear of the second main ducted, and the front end of the V-shaped tail corresponds to the center of the second main ducted. The diameter of the auxiliary ducted fan is 50 - 60% of the diameter of the main ducted fan.

[0037] The large-load UAV of the present invention optimizes the design of the fuselage layout. By adopting this optimized layout scheme, the load of the UAV can be increased to the ton level and the cruising speed can be significantly improved.

[0038] Furthermore, the main duct and the auxiliary duct penetrate vertically. The duct wall is connected to the fuselage and wing skins around the circumference. After the duct grille is closed, the upper and lower parts can be completely sealed. The main duct wall is connected to the fuselage beam, the front and rear ends of the auxiliary duct wall are connected to the wing beams, and one side of the auxiliary duct wall is connected to the fuselage frame. The duct fan is fixed in the duct by a cross bracket, and the lower end of the duct fan is connected to the transmission shaft. The duct is manufactured by integral molding to reduce the connection between parts.

[0039] In the present invention, the outer shapes of the main duct and the auxiliary duct are integrated with the fuselage and wings. The grilles at the upper and lower ends of the duct wall are designed according to the aerodynamic shape structure, and a transition layout is adopted at the structural connection. In this duct design form, the duct can be used as a load-bearing structure of the airframe. The outer wall of the main duct is connected to the fuselage beam, and the main duct can act as a fuselage frame to play a connecting and supporting role. The auxiliary duct can be used as a load-bearing structure to connect the fuselage and the wings. The front and rear ends of the auxiliary duct wall are connected to the wing beams, and one side of the auxiliary duct wall is connected to the fuselage frame. During the flight of the UAV, the auxiliary duct can cooperate with the wing beam to transfer the wing load to the fuselage.

[0040] Furthermore, louvered grilles are provided at the upper and lower ends of the main duct and the auxiliary duct. The grilles can be deflected and closed as required. The individual duct grilles are designed with a linkage structure. The grilles are connected to the rack. The rack is arranged at the center position at one end of the duct, perpendicular to the grille direction. The two ends of the rack are inserted through the duct wall. The servo is arranged at one end of the rack and fixed on the outer wall of the duct. The servo is connected to the gear arranged on the rack through a linkage mechanism. By controlling the rotation of the servo to drive the gear to rotate, the movement of the rack can be realized, and the deflection and closing of the grille can be completed. During the vertical takeoff and landing of the UAV, the main duct grille is fully opened, and the auxiliary duct grille is deflected by a certain angle to control the attitude of the UAV. During the cruise of the UAV, all grilles are closed. The grilles are arranged in the front-rear direction and can rotate left and right. Each group of grilles is independently provided with a servo. The servo is controlled by the control system to adjust the opening angle and direction of the grille, so as to realize the control of the flight mode of the UAV.

[0041] Furthermore, a modular cargo hold is arranged in the middle of the belly of the fuselage and the front and rear main ducts. The cargo hold is a modular cargo hold, and the installation interface of the fuselage adopts a modular design. The installation and disassembly of the cargo hold can be quickly realized without tools, improving the use efficiency of the UAV, and different types of cargo holds can be replaced according to the mission requirements.

[0042] Furthermore, a four-point landing gear is arranged on the belly of the fuselage. The main ducted fans occupy both the front and rear ends of the fuselage. A cargo hold is arranged between the front and rear main ducted fans. The four-point landing gear is symmetrically arranged on the left and right between the cargo hold and the main ducted fans. The front two landing gears can be retracted backward into the interior of the fuselage, and the rear two landing gears can be retracted forward into the interior of the fuselage. This wheeled landing gear is used for the ground parking, taxiing, takeoff, and landing roll of the UAV. After retraction, the landing gear is completely located inside the fuselage, reducing flight resistance.

[0043] Furthermore, the left and right wings are symmetrically arranged, and flaps and ailerons are respectively arranged on the wings; left and right tail fin control surfaces are symmetrically arranged on the V-shaped tail fin. The flap-aileron control surfaces and the tail fin control surfaces are used to adjust the flight attitude of the UAV during the cruise state and provide control forces. The flap-aileron control surfaces and the tail fin control surfaces are symmetrically arranged on the left and right, and their sizes are determined according to the overall technical specifications. During flight, the flight attitude of the UAV is controlled by relying on the traditional control surface structure, and the control difficulty is low.

[0044] Furthermore, a propeller is arranged at the front end of the nose. It is used to provide flight thrust during the takeoff roll and fixed-wing mode cruise of the UAV.

[0045] Furthermore, the main ducted fan is powered by a turboshaft engine, and the auxiliary ducted fan is powered by an electric motor; the power of the engine and the electric motor is transmitted through a shaft drive and is transmitted to the ducted fan in cooperation with a clutch; during the vertical takeoff and landing process of the UAV, the power of the turboshaft engine is greater than the sum of the powers of the main and auxiliary ducted fans. The propeller is powered by a turboshaft engine, and the engine power is transmitted through a shaft drive and is transmitted to the propeller in cooperation with a clutch.

[0046] The present invention also provides a modular cargo hold for a UAV. The cargo hold adopts a modular structural shape design. The connection between the cargo hold and the UAV fuselage structure uses a modular installation interface. Standardized fixed lugs are provided on the cargo hold, and connection lugs and electric push rods are arranged at corresponding positions on the fuselage. When the cargo hold is pushed into the interior of the fuselage with the help of a crane, the electric push rod starts to extend to fix the fuselage connection lug and the cargo hold fixed lug.

[0047] The bottom configuration of the cargo hold is consistent with the outer shape of the fuselage belly skin. The cargo hold is loaded into the fuselage from the belly of the UAV. After the cargo hold is installed, no additional fuselage hatch is required for shaping the fuselage belly.

[0048] The internal structure and functions of the cargo hold can be adaptively modified according to different mission requirements. The cargo hold can be used as a standardized cargo hold to transport ammunition and support equipment, etc., and can be used as a rescue shelter for the transportation of medical equipment, drugs, and the rescue of the wounded.

[0049] After the cargo hold is installed on the fuselage and connected to the fuselage, it has a certain force transmission and load-bearing capacity.

[0050] The modular cargo hold structure design can quickly realize the installation and disassembly of the cargo hold, reduce the operation processes, improve the work efficiency, and enable automated operation. The modular cargo hold has better adaptability to mission requirements and can achieve different load-bearing functions according to different mission requirements. The cargo hold adopts a conformal structure design, with a larger volume and greater transportation capacity. The modular cargo hold can improve the efficiency of UAV transportation, enhance the distribution efficiency of logistics, and meet the requirements of feeder logistics transportation.

[0051] The technical solution of the present invention will be elaborated in detail below in conjunction with a specific embodiment.

[0052] As Figure 1 、 2 shown, the entire UAV includes a fuselage 1, a left wing 2, a right wing 3, V-shaped tails 8 and 9, first and second main ducts 12 and 13 arranged before and after the fuselage 1, first and second auxiliary ducts 14 and 15 arranged at the wing-body fusion, a propeller 16 arranged at the front end of the fuselage 1, and wheeled landing gears 17 and a cargo hold 18 arranged at the lower end of the fuselage 1.

[0053] A left flap control surface 4 and a left aileron control surface 5 are arranged on the left wing 2; a right flap control surface 6 and a right aileron control surface 7 are arranged on the right wing 3; a left tail control surface 10 is arranged on the left tail 8; and a right tail control surface 11 is arranged on the right tail 9.

[0054] The fans of the main ducts 12 and 13 are powered by a turboshaft engine, and the engine power is transmitted through a shaft and transferred to the main duct fans in cooperation with a clutch. The fans of the auxiliary ducts 14 and 15 are powered by an electric motor, and the electric motor power is transmitted through a shaft and transferred to the auxiliary duct fans in cooperation with a clutch. The propeller 16 is powered by a turboshaft engine, and the engine power is transmitted through a shaft and transferred to the propeller in cooperation with a clutch.

[0055] Louvered grilles are provided at both the upper and lower ends of the ducts 12, 13, 14, and 15. The grilles can control the deflection angle according to requirements, thereby providing vertical lift power and controlling the flight attitude of the UAV. When the UAV takes off and lands vertically or hovers in the air, as Figure 1 shown, the grilles open, and the fans of the main ducts 12 and 13 provide vertical lift, while the fans of the auxiliary ducts 14 and 15 control the attitude of the UAV. When the UAV is cruising, all the grilles close, as Figure 3 shown, and the UAV flies completely in the fixed-wing mode.

[0056] The UAV of the present invention is provided with a modular cargo hold 18 on the abdomen of the fuselage 1. The installation interfaces between the modular cargo hold 18 and the fuselage 1 are all modularly designed, and the installation and disassembly of the cargo hold 18 can be quickly realized without using tools, improving the use efficiency of the UAV.

[0057] Figure 4 It is a schematic diagram of the modular cargo hold structure. The modular cargo hold includes the main structure 101 of the cargo hold, standardized fixed lugs 102 and positioning guide grooves 104 located on the front and rear side walls. An electric push rod insertion hole 103 is provided on the fixed lug 102. The front end of the insertion hole 103 has a certain guiding taper to facilitate the insertion of the electric push rod. For the positioning guide groove 104, its upper end has a certain guiding taper to facilitate controlling the installation angle of the cargo hold during the lifting process of the cargo hold. The guide groove cooperates with the guide blocks arranged on the fuselage. The positioning guide groove can prevent the problem of jamming due to angle deviation during the lifting and lowering process of the cargo hold.

[0058] Figure 5 It is a schematic diagram of the modular cargo hold fixing structure. The fixing structure includes connecting lugs 106 and electric push rods 108. Both the connecting lugs 106 and the electric push rods 108 are fixed on the fuselage frame plate 105. An electric push rod insertion hole 107 is provided on the connecting lug 106. The front end of the insertion hole 107 has a certain guiding taper to facilitate the insertion of the electric push rod. For the electric push rod 108, its main body is fixed on the fuselage frame plate 105, and its interior contains a telescopic and movable insertion rod 109. A certain guiding taper is also provided at the front end of the insertion rod 109. After the insertion rod 109 is inserted into the fixed lug 102 and the connecting lug 106, the cargo hold can be fixed to the fuselage. The number and positions of the fixed lugs, connecting lugs and electric push rods correspond one by one. In this embodiment, the number of installation lugs is 4, and the number of connecting lugs and electric push rods is also 4.

[0059] Figure 6 It is a schematic diagram of the state during the lifting process of the modular cargo hold. When the cargo hold needs to be installed into the fuselage, first, the cargo hold is lifted to a certain height by means of a lift truck. Under the guidance of the guide groove 104, the cargo hold slowly rises along the guide groove 104. When the cargo hold rises to the end of the guide groove 104, the electric push rod 108 starts to work, and the insertion rod 109 extends out, penetrating the fixed lug 102 and the connecting lug 106. In this state, the four electric push rods on the front and rear walls of the cargo hold act simultaneously to fix the cargo hold. After the cargo hold is fixed, its bottom is consistent with the outer shape of the fuselage skin.

[0060] In this embodiment, the maximum designed vertical takeoff and landing weight of the UAV is 1500 kg. The diameter of a single main duct is 2.25 m, and it can provide a lift force of 780 kg in the vertical takeoff and landing state. Considering the losses in the actual working state, the efficiency coefficient of the front main duct is taken as 0.82, and the efficiency coefficient of the rear main duct is taken as 0.8. The diameter of a single auxiliary duct is 1.35 m, and it can provide a lift force of 150 kg in the vertical takeoff and landing state. Considering the losses in the actual working state, the efficiency coefficient of the auxiliary duct is taken as 0.8. Calculate the lift force that the ducts of the UAV can provide in the actual engineering working state. The actual lift force is 1504 kg, meeting the requirement that the maximum takeoff and landing weight of the UAV is 1500 kg.

[0061] The operating principle of the large-load transport UAV based on ducted fans is as follows.

[0062] Case 1: Takeoff and landing of the UAV in the environment of a normal runway area.

[0063] Under the condition of meeting the requirements for takeoff by taxiing, the UAV can take off by taxiing. The transporter directly transports the cargo compartment 18 to the abdomen of the UAV fuselage 1, and uses the modular installation interface to quickly complete the installation of the cargo compartment 18, and then the transporter withdraws. The UAV taxis to the runway. At this time, the grilles of the ducted fans 12, 13, 14, and 15 are completely closed, and the UAV completes the takeoff by taxiing completely in the fixed-wing mode. In this state, the UAV can achieve the cargo transportation capacity with an ultra-large load.

[0064] Case 2: Takeoff and landing of the UAV in areas such as mountains, narrow sites, and islands.

[0065] In mountainous areas, islands, and narrow site areas where there is no sufficiently long runway or the runway length is short, the UAV can take off and land vertically. After the modular cargo compartment 18 is installed, the grilles of the ducted fans 12, 13, 14, and 15 are completely opened. The fans of the main ducted fans 12 and 13 work to generate vertical lift, and the UAV takes off vertically. The fans of the auxiliary ducted fans 14 and 15 continuously adjust the flight attitude of the UAV to ensure the stability of the UAV. When the UAV converts from the hovering state to the level flight state, the propeller 16 at the front end of the fuselage 1 starts to work. The ducted fans adjust their lift and continuously adjust the flight attitude of the UAV. The horizontal speed of the UAV continuously increases. When it reaches the level flight state, the ducted fan grilles are completely closed, and the UAV flies completely in the fixed-wing mode.

[0066] Features described and / or illustrated for one embodiment as above can be used in the same or similar manner in one or more other embodiments, and / or combined with the features in other embodiments or used to replace the features in other embodiments.

[0067] It should be emphasized that the term "comprising / including" when used herein refers to the presence of features, whole things, steps, or components, but does not exclude the presence or addition of one or more other features, whole things, steps, components, or combinations thereof.

[0068] Many features and advantages of these embodiments are clear from this detailed description. Therefore, the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. In addition, since many modifications and changes are easily conceivable by those skilled in the art, the embodiments of the present invention are not to be limited to the exact structures and operations illustrated and described, but may cover all suitable modifications and equivalents falling within their scope.

[0069] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0070] The parts not detailed in the present invention are well-known technologies to those skilled in the art.

Claims

1. A large-load transport UAV based on a ducted fan, characterized in that, It includes a fuselage, left and right wings, a V-shaped tail, a main duct arranged at the front and rear of the fuselage, and an auxiliary duct arranged at the fuselage-wing integration part; the fuselage adopts a lifting body structure, the belly of the fuselage is flat, and the back is of a flat-convex shape. The lower part of the front end of the first main duct of the fuselage is designed into an arc-shaped concave surface, and the rear end is tangent to the lower edge of the first main duct; the main duct fan and the auxiliary duct fan are both horizontally arranged in the body duct, and grille matching the aerodynamic shape of the UAV is provided at the upper and lower ends of the main duct and the auxiliary duct; The maximum transverse dimension of the UAV fuselage is 1 / 3 to 2 / 5 of the longitudinal dimension, the wingspan is 3 to 3.5 times the maximum transverse dimension of the fuselage, the centers of the first and second main ducts are respectively at 1 / 3 and 5 / 6 of the distance from the front end of the fuselage, the center of the auxiliary duct is located at the fuselage-wing integration part and at 1 / 2 to 3 / 5 of the longitudinal dimension of the fuselage, the V-shaped tail is located at the rear side of the second main duct, and the front end of the V-shaped tail corresponds to the center of the second main duct; the diameter of the auxiliary duct fan is 50 to 60% of the diameter of the main duct fan; The grille is of a louver type, and each group of grilles adopts a linkage structure. The grille is connected to a rack, the rack is arranged at the center position at one end of the duct and is perpendicular to the direction of the grille. Both ends of the rack are inserted through the duct wall, and a servo motor is arranged at one end of the rack and fixed on the outer wall of the duct. The servo motor is connected to a gear arranged on the rack through a linkage mechanism. By controlling the rotation of the servo motor to drive the gear to rotate, the movement of the rack is realized, and the deflection and closing of the grille are completed.

2. The large-load transport UAV according to claim 1, wherein The main duct and the auxiliary duct penetrate up and down. The duct wall is connected to the fuselage and wing skins. After the duct grille is closed, it is completely enclosed up and down; the main duct wall is connected to the fuselage beam, the front and rear ends of the auxiliary duct wall are connected to the wing beam, and one side of the auxiliary duct wall is connected to the fuselage frame; the duct fan is installed in the duct through a bracket.

3. The large-load transport UAV according to claim 1, wherein The belly of the fuselage is provided with a landing gear and a modular cargo hold.

4. The large-load transport unmanned aerial vehicle according to claim 3, wherein The modular cargo hold is arranged between the belly of the fuselage and the front and rear main ducts. The fuselage is provided with modular installation interfaces. The modular cargo hold is provided with fixed lugs, and corresponding connection lugs and electric push rods are arranged at the corresponding positions on the fuselage. The electric push rod extends out to fix the connection lug on the fuselage and the fixed lug on the cargo hold.

5. The large-load transport UAV according to claim 4, wherein, Positioning and guiding grooves are also provided on the front and rear side walls of the modular cargo hold, which cooperate with the guiding blocks on the fuselage; the fixed lugs and the connection lugs are provided with electric push rod insertion holes with a certain taper at the front end, and the front end of the electric push rod also has a certain taper.

6. The large-load transport UAV according to claim 3, wherein, The bottom configuration of the modular cargo hold is consistent with the shape of the belly skin of the fuselage; the internal structure and functions of the modular cargo hold are adaptively modified according to different mission requirements.

7. The large-load transport UAV according to claim 3, wherein The landing gear adopts a four-point landing gear, which is symmetrically arranged on the left and right between the cargo hold and the main duct. The front two landing gears can be retracted backward into the fuselage, and the rear two landing gears can be retracted forward into the fuselage.

8. The large-load transport unmanned aerial vehicle according to claim 1, wherein Flaps and ailerons are symmetrically arranged on the left and right wings, and left and right tail fin control surfaces are symmetrically provided on the V-shaped tail fin; a propeller is arranged at the front end of the nose; the main ducted fan is powered by a turboshaft engine, the auxiliary ducted fan is powered by an electric motor, the propeller is powered by a turboshaft engine, and the power of the engine and the electric motor is transmitted through a shaft and cooperates with a clutch to be transmitted to the ducted fan or the propeller.

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