Tilting power vertical take-off and landing unmanned aerial vehicle adopting linked wing layout

Abstract

The invention discloses a tiltable power vertical take-off and landing unmanned aerial vehicle adopting a linked wing layout. The tiltable power vertical take-off and landing unmanned aerial vehicle comprises a fuselage, a pair of front wings, a pair of rear wings, a tail connecting wing and a side end connecting wing, the pair of front wings are respectively connected to two sides of the head of the fuselage; the pair of rear wings are respectively arranged on two sides above the rear part of the fuselage; the tail connecting wing is arranged on the upper side of the rear part of the fuselage and is respectively connected with the rear wings on the two sides; wingtips of the rear wings are connected with the front wings through the side end connecting wings. A front propeller is mounted on the lower side of each front wing, a lower hanging type mounting arm capable of tilting and adjusting in the front-back direction is arranged on the lower side of each rear wing, and a rear propeller is mounted at the tail end of the lower hanging type mounting arm. The influence of the downward washing flow field of the front wing on the rear wing can be reduced, the lift-drag ratio of the rear wing is increased, meanwhile, the dead weight is reduced, and the cruising ability is improved.

Description

Technical Field

[0001] The invention relates to the field of aerospace and low-altitude equipment technology, and in particular to a tiltable powered vertical take-off and landing UAV with a linked-wing layout. Background Art

[0002] Currently, most small and medium-sized vertical take-off and landing composite wing drones use conventional aerodynamic layout, and their payload and endurance are their shortcomings. Even a few drones with slightly longer flight times have relatively small payloads.

[0003] There are some new layouts on the market to solve the above problems, such as the tandem wing layout of the front and rear wings (refer to the tandem wing UAV disclosed in Chinese invention patent CN218112983U), or the combined wing layout (specifically, refer to the combined wing UAV that can take off and land vertically disclosed in Chinese invention patent CN207860452U). The induced drag of the tandem wing layout is greater than that of the combined wing layout, and the structural strength is not as good as that of the combined wing layout.

[0004] The existing vertical take-off and landing UAVs with a combined wing layout have problems such as low efficiency in the layout of the vertical take-off and landing propellers and great interference with the flow field of the main wing.

[0005] Moreover, both the current tandem-wing layout and coupled-wing layout vertical take-off and landing UAV technologies have the defect that the rear wing is affected by the downwash of the front wing, resulting in a low lift-to-drag ratio, which affects the lift-to-drag ratio of the entire aircraft.

[0006] In addition, the rotor power and tail thrust are set independently. In different flight modes, the other power system will bring greater dead weight and reduce the flight time of the entire aircraft. Summary of the invention

[0007] In view of the defects in the prior art, the present invention provides a tiltable powered vertical take-off and landing UAV with a linked wing layout to reduce the influence of the downwash flow field of the front wing on the rear wing, improve the lift-to-drag ratio of the rear wing, reduce the dead weight, and improve the endurance.

[0008] The present invention provides a tiltable powered vertical take-off and landing UAV adopting a linked wing layout, comprising:

[0009] body;

[0010] A pair of front wings, the pair of front wings are respectively connected to both sides of the fuselage head;

[0011] A pair of rear wings, the pair of rear wings are respectively arranged on both sides above the rear part of the fuselage;

[0012] A tail connecting wing, which is arranged on the upper side of the rear part of the fuselage and is respectively connected to the rear wings on both sides;

[0013] Side connecting wings, the wing tips of the rear wings are connected to the front wings respectively through the side connecting wings;

[0014] Among them, a front propeller is installed on the lower side of each front wing, and a lower side of each rear wing is provided with a lower hanging mounting arm that can be tilted and adjusted in the front and rear directions, and a rear propeller is installed at the end of the lower hanging mounting arm.

[0015] Furthermore, the front wing is a swept wing, a section of the rear wing connected to the wing near the tail is a straight wing, and a section of the rear wing connected to the wing near the side end is a forward swept wing.

[0016] Furthermore, the sweep angle of the leading edge of the swept-back wing is 23.5°±2°, and the sweep angle of the leading edge of the forward-swept wing is 13°±2°.

[0017] Furthermore, the installation angle of the front wing is greater than the installation angle of the rear wing.

[0018] Furthermore, the tail connecting wing includes two connecting wing panels arranged in a V-shape, one end of the two connecting wing panels is respectively fixed to the fuselage, and the other ends of the two connecting wing panels are respectively connected to the rear wings on both sides.

[0019] Furthermore, a rudder surface is provided on the rear side of the two connecting wing plates.

[0020] Furthermore, a front-mounted mounting arm is provided on the front side of the front wing, and the front propeller is mounted on the lower side of the front-mounted mounting arm.

[0021] Furthermore, the maximum forward tilting angle of the under-mounted mounting arm is α, and the axial angle β between the under-mounted mounting arm and the rear propeller is 180°-α.

[0022] Furthermore, the maximum forward tilting angle α of the under-hanging installation arm is 20°+5°, and the maximum backward tilting angle γ of the under-hanging installation arm is 130°±5°.

[0023] Furthermore, a main landing gear is provided on the lower side of the front part of the fuselage, and a tail fin is provided on the lower side of the tail part of the fuselage.

[0024] The beneficial effects of the present invention are embodied in:

[0025] When the UAV takes off and lands vertically, the lower-mounted mounting arm is driven to tilt forward so that the rear propeller at the end of the lower-mounted mounting arm points downward. The two front propellers and the rear propeller can provide a stable vertical lift for the UAV. When the UAV turns to a level flight state, the lower-mounted mounting arm gradually turns backward under the control of the flight control system, providing tail thrust for the UAV's horizontal flight. In this way, there is no need to set the tail thrust separately, which can reduce the dead weight of the entire machine and improve endurance.

[0026] More importantly, in level flight, the rear propeller rotates to the rear side of the rear wing, providing tail thrust while also actively controlling the flow field. On the one hand, the airflow on the rear wing is rectified, minimizing the impact of the downwash flow field of the front wing on the rear wing, greatly improving the lift-to-drag ratio of the rear wing. On the other hand, the direction of rotation of the airflow passing through the rear propeller is opposite to that of the wingtip vortex, further offsetting the downwash caused by the wingtip vortex and further improving the lift-to-drag ratio of the rear wing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0028] Figure 1 is a three-dimensional structural diagram of an embodiment of the present invention;

[0029] Figure 2 A top view of an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of a vertical take-off and landing embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of an embodiment of the present invention in a level flight state;

[0032] Figure 5 It is a schematic diagram of the rotation direction of the airflow flowing through the rear propeller and the direction of the wingtip vortex according to an embodiment of the present invention;

[0033] Figure 6 It is a schematic diagram of the control surfaces on two connected wing plates acting as elevators in an embodiment of the present invention;

[0034] Figure 7 It is a schematic diagram of the control surfaces on the two connected wing panels acting as a rudder in an embodiment of the present invention.

[0035] In the attached drawings, 100-fuselage; 200-front wing; 300-rear wing; 310-straight wing; 320-forward swept wing; 400-tail connecting wing; 410-connecting wing panel; 420-rudder; 500-side connecting wing; 610-front propeller; 620-front hanging mounting arm; 710-underhanging mounting arm; 720-rear propeller; 800-main landing gear; 900-tail fin. DETAILED DESCRIPTION

[0036] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0037] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0038] like Figure 1-Figure 7 As shown, an embodiment of the present invention provides a tiltable powered vertical take-off and landing UAV with a linked wing layout, including a fuselage 100, a pair of front wings 200, a pair of rear wings 300, a tail connecting wing 400 and a side connecting wing 500.

[0039] The pair of front wings 200 are respectively connected to both sides of the head of the fuselage 100 .

[0040] In this embodiment, the front wing 200 is a swept wing, and the sweep angle of the leading edge of the swept wing is 23.5°±2°, preferably 23.5°.

[0041] The pair of rear wings 300 are respectively disposed on both sides of the upper rear portion of the fuselage 100 .

[0042] In this embodiment, a section of the rear wing 300 connected to the wing 400 at the tail end is a straight wing 310, and a section connected to the wing 500 at the side end is a forward-swept wing 320. The sweep angle of the leading edge of the forward-swept wing 320 is 13°±2°, preferably 13°.

[0043] In this embodiment, the installation angle of the front wing 200 is greater than the installation angle of the rear wing 300, where the installation angle refers to the angle between the width direction of the wing and the horizontal.

[0044] The tail connecting wing 400 is disposed on the upper side of the rear portion of the fuselage 100 and is connected to the rear wings 300 on both sides respectively.

[0045] Preferably, the tail connecting wing 400 includes two V-shaped connecting wing panels 410, one end of the two connecting wing panels 410 is respectively fixed to the fuselage 100, and the other ends of the two connecting wing panels 410 are respectively connected to the rear wings 300 on both sides.

[0046] In this embodiment, the tail connecting wing 400 is designed to be V-shaped, which can reduce interference resistance. At the same time, the rear wings 300 on both sides avoid the middle area where the downwash field of the front wing is the strongest, so that the flow field of the rear wing is greatly improved by the downwash of the front wing. In addition, the tail connecting wing 400 between the rear wings 300 on both sides is designed to be V-shaped, which has better stress conditions than the existing T-shaped structure.

[0047] Preferably, the rear sides of the two connecting wing plates 410 are provided with a rudder surface 420. Figure 6 When the rudder surfaces 420 on the two connecting wing plates 410 are both tilted inward, they can play the role of elevators. Figure 7 When the rudder surfaces 420 on the two connecting wing panels 410 are deflected to the same side, they can play the role of a rudder. Therefore, in this embodiment, the rudder surfaces 420 are arranged on the rear sides of the two connecting wing panels 410, which can play the role of an elevator and a rudder at the same time.

[0048] Optionally, the two connecting wing panels 410 of the tail connecting wing 400 have a certain sweep angle to reduce the resistance in level flight.

[0049] The wing tips of each rear wing 300 are connected to the side end connecting wing 500 between the front wings 200 through the side end connecting wing 500, which can reduce the induced drag and strengthen the front and rear wing structures.

[0050] Optionally, the side connecting wing 500 and the front wing 200 and the rear wing 300 are of quick-detachable design for easy transportation and installation.

[0051] A front propeller 610 is installed on the lower side of each front wing 200 , and a lower hanging mounting arm 710 that can be tilted and adjusted in the front-rear direction is provided on the lower side of each rear wing 300 , and a rear propeller 720 is installed at the end of the lower hanging mounting arm 710 .

[0052] It is understandable that the tilt adjustment of the under-hanging mounting arm 710 can be driven by a motor, hydraulic pressure, etc. This embodiment does not impose any specific restrictions on it, and it is preferably driven by a motor.

[0053] Optionally, a front-mounted mounting arm 620 is provided on the front side of the front wing 200, and the front propeller 610 is installed on the lower side of the front-mounted mounting arm 620. The front-mounted mounting arm 620 has a fairing shape, which can reduce resistance while ensuring the aerodynamic efficiency of the front propeller 610 during vertical lift.

[0054] In this embodiment, refer to Figure 3 , the maximum angle at which the under-mounted mounting arm 710 tilts forward is α, and the axis angle β between the under-mounted mounting arm 710 and the rear propeller 720 is 180°-α. When the under-mounted mounting arm 710 tilts forward at the maximum angle, the rear propeller 720 is just vertically downward, which can reduce the influence of the rear wing 300 on the aerodynamic efficiency of the rear propeller 720.

[0055] Specifically, refer to Figure 3 and Figure 4 The maximum forward tilting angle α of the hanging mounting arm 710 is 20°+5°, preferably 20°, and the maximum backward tilting angle γ of the hanging mounting arm 710 is 130°±5°, preferably 130°.

[0056] In this embodiment, a main landing gear 800 is provided on the lower side of the front portion of the fuselage 100, and a tail fin 900 is provided on the lower side of the tail portion of the fuselage 100. The tail fin 900 can enhance the heading stability of the UAV, and can also serve as a support point when parking on the ground to support the UAV together with the two-point main landing gear 800 at the front portion of the fuselage 100.

[0057] Optionally, the tail fin 900 has a certain sweep angle to reduce the drag in level flight.

[0058] Reference Figure 3 When the UAV takes off and lands vertically, the lower mounting arm 710 is driven to tilt forward so that the rear propeller 720 at the end of the lower mounting arm 710 faces downward. The two front propellers 610 and the rear propeller 720 can provide a stable vertical lift for the UAV. Figure 4 When the UAV turns to a level flight state, the under-hung mounting arm 710 gradually turns backward under the control of the flight control system to provide tail thrust for the horizontal flight of the UAV. In this way, there is no need to set a separate tail thrust, which can reduce the dead weight of the entire machine and improve endurance.

[0059] More importantly, in the level flight state, the rear propeller 720 rotates to the rear side of the rear wing 300, and while providing tail thrust, it can also actively control the flow field. On the one hand, the airflow of the rear wing 300 is rectified, which minimizes the influence of the downwash flow field of the front wing 200 on the rear wing 300, greatly improving the lift-to-drag ratio of the rear wing 300. On the other hand, the rotation direction of the airflow flowing through the rear propeller 720 (see Figure 5 The arrow direction around the middle rear propeller 720) and the wing tip vortex direction (see Figure 5 The direction of the arrows around the wingtips of the middle and rear wing 300 is opposite to that of the arrows to offset the downwash caused by the wingtip vortices and further improve the lift-to-drag ratio of the rear wing 300.

[0060] In summary, this embodiment minimizes the influence of the downwash flow field of the front wing 200 on the rear wing 300 through different sweep angles, aspect ratios, plane shapes, installation angles of the front and rear wings 300, and the V-shaped design of the middle section of the rear wing, and the active rectification of the airflow after the rear propeller 720 is tilted, so that the lift-to-drag ratio of the rear wing 300 is greatly improved, and the efficiency is increased from 50%-60% of the efficiency of the front wing 200 to 70%-75%. Combined with the optimized rectification-type front-mounted mounting arm 620 to reduce the drag in the level flight state, the lift-to-drag ratio of the whole aircraft can be improved by 35%-40%.

[0061] Through the tiltable tail thrust system, the dead weight of the entire aircraft is reduced by 60% and the endurance performance is greatly improved.

[0062] By adopting the above-mentioned tiltable powered vertical take-off and landing UAV with a combined wing layout, on the basis of the same wingspan size, compared with a conventional composite wing vertical take-off and landing UAV, the UAV of this embodiment has a 100-130% higher load capacity and a 60-80% higher endurance; compared with the tandem wing vertical take-off and landing UAV technology, the UAV of this embodiment has a 50-80% higher load capacity and a 50-65% higher endurance; compared with the existing combined wing layout vertical take-off and landing UAV technology, the UAV of this embodiment has a 50% higher load capacity and a 30% higher endurance.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A tiltable powered vertical take-off and landing UAV with a combined wing layout, characterized in that: include: body; A pair of front wings, the pair of front wings are respectively connected to both sides of the fuselage head; A pair of rear wings, the pair of rear wings are respectively arranged on both sides above the rear part of the fuselage; A tail connecting wing, which is arranged on the upper side of the rear part of the fuselage and is respectively connected to the rear wings on both sides; Side connecting wings, the wing tips of the rear wings are connected to the front wings respectively through the side connecting wings; Among them, a front propeller is installed on the lower side of each front wing, and a lower side of each rear wing is provided with a lower hanging mounting arm that can be tilted and adjusted in the front and rear directions, and a rear propeller is installed at the end of the lower hanging mounting arm.

2. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 1 is characterized in that: The front wing is a swept wing, a section of the rear wing connected to the wing near the tail is a straight wing, and a section of the rear wing connected to the wing near the side end is a forward swept wing.

3. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 2 is characterized in that: The sweep angle of the leading edge of the swept-back wing is 23.5°±2°, and the sweep angle of the leading edge of the forward-swept wing is 13°±2°.

4. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 1, characterized in that: The installation angle of the front wing is greater than the installation angle of the rear wing.

5. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 1, characterized in that: The tail connecting wing comprises two connecting wing panels arranged in a V shape, one end of the two connecting wing panels is respectively fixed to the fuselage, and the other ends of the two connecting wing panels are respectively connected to the rear wings on both sides.

6. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 5, characterized in that: The rear sides of the two connecting wing plates are provided with rudder surfaces.

7. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 1, characterized in that: A front-mounted mounting arm is arranged at the front side of the front wing, and the front propeller is mounted on the lower side of the front-mounted mounting arm.

8. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 1, characterized in that: The maximum angle at which the under-mounted mounting arm can tilt forward is α, and the axis angle β between the under-mounted mounting arm and the rear propeller is 180°-α.

9. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 7, characterized in that: The maximum angle α of the downward-hanging installation arm tilting forward is 20°+5°, and the maximum angle γ of the downward-hanging installation arm tilting backward is 130°±5°.

10. The tiltable powered vertical take-off and landing UAV with a combined wing layout according to claim 1, characterized in that: A main landing gear is arranged on the lower side of the front part of the fuselage, and a tail fin is arranged on the lower side of the tail part of the fuselage.

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