A small long-endurance UAV with dual engines

Abstract

The present invention provides a small long-endurance unmanned aerial vehicle with dual engines, which adopts a piston engine with high efficiency and low fuel consumption rate, and optimizes the overall shape design to improve the lift-drag ratio; uses an efficient energy management system to monitor and control flight power consumption in real time, improving energy utilization efficiency; reasonably designs and effectively integrates quick-release buckles and electrical system interfaces for each component, enhancing operation convenience and reducing operation and maintenance difficulty; uses high-performance composite materials and optimized ply design to significantly reduce the structural weight, thereby achieving an ultra-long endurance flight duration (more than 24 hours) of the unmanned aerial vehicle and improving the operation efficiency of the unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention relates to an unmanned aerial vehicle, belonging to the technical field of aircraft design in unmanned aerial vehicles. Background Art

[0002] The existing pure electric tilt-rotor unmanned aerial vehicles have a short flight time, within 1 hour, and carry less payload; the hybrid and fuel-powered unmanned aerial vehicles have a long flight time, but are inconvenient to use and maintain, have complex operations, and have large vibrations, which affect the measurement results of the mission payload. In addition, most of the existing long-endurance unmanned aerial vehicles use a takeoff method of taxiing, and the takeoff process requires a dedicated runway, and has high requirements for the width, length, and surrounding environment of the runway, which is not conducive to portable management and flexible configuration.

[0003] In the proposed solution of this application, compared with conventional long-endurance unmanned aerial vehicles, a fuel engine solution is adopted, and the lift-drag ratio is improved through excellent aerodynamic shape optimization design; an efficient energy management system can monitor the flight power consumption in real time and improve the energy utilization rate; reasonable design and effective integration are carried out on the quick-release buckles of each component, electrical system interfaces, etc.; high-performance composite materials are used to greatly reduce the structural weight, so as to achieve an ultra-long flight endurance time (more than 24 hours) of the unmanned aerial vehicle and improve the operation efficiency of the unmanned aerial vehicle. Summary of the Invention

[0004] According to one aspect of the present invention, a small long-endurance unmanned aerial vehicle with a dual engine is provided, which is characterized by including:

[0005] A fuselage, wings, horizontal tail, and power device,

[0006] Wherein:

[0007] The fuselage is designed with a streamlined shape with low flight resistance, and the nose is a blunt body.

[0008] The fuselage includes a front fuselage and a rear fuselage. The front fuselage and the rear fuselage are sleeved through a connecting frame section. The front and rear two connecting frame sections are fastened by four first bolts. The upper semi-circular groove of the connecting frame section has a smaller external dimension than the lower semi-circular groove. Therefore, it can prevent installers from installing the front fuselage and the rear fuselage upside down, ensuring the quick and reliable installation connection of the front fuselage and the rear fuselage in an outdoor site.

[0009] Three large opening areas are provided on the upper part of the front fuselage: a front equipment hatch, a middle wing mounting surface, and a rear parachute hatch.

[0010] The front equipment hatch is formed by a sandwich structure of "wave-transparent glass fiber + polymethacrylimide foam" to avoid shielding and / or screening of the electromagnetic waves of the antennas inside the fuselage.

[0011] The rear parachute bay cover and the front fuselage adopt a rear torsion spring hinge + front servo closed control. When the rear parachute bay cover needs to be opened, the front servo deflects 90 degrees, causing the rear parachute bay cover to automatically bounce backward under the action of the rear torsion spring, facilitating the release of the internal parachute.

[0012] A small maintenance access cover is provided at the lower part of the rear fuselage to facilitate the installation and debugging of airborne equipment.

[0013] The rear fuselage and the vertical tail are integrally formed, thereby reducing the setting of frames and ribs inside.

[0014] A rudder is provided at the rear of the vertical tail.

[0015] The tip of the rudder extends forward to the leading edge of the vertical tail, forming an aerodynamic compensation structure to reduce the hinge moment and / or load of the rudder.

[0016] The rudder is jointly controlled by two servos to improve reliability.

[0017] The front fuselage and the central wing are fastened by multiple second bolts in the up, down, left, and right directions. The second bolts are installed and fastened through the lower parachute bay space of the rear parachute bay cover, without adding additional processes and maintenance access covers to the fuselage.

[0018] The wing is of a double-beam structure, including a central wing, outer wing segments, winglets, and ailerons. A power plant is suspended in front of the central wing through a suspension structure, and the suspension structure is integrally co-cured with the central wing to reduce the structural weight; the central wing is connected to the fuselage vertically.

[0019] A metal structural member connected to the ejection rack is provided at the lower part of the central wing to realize the fixation and release of the UAV on the ejection rack.

[0020] The wing has a large aspect ratio, the leading edge is an S-shaped curve, and the central wing of the wing is integrated with the fuselage.

[0021] The wing converges at the winglets to reduce the induced drag of the wing.

[0022] The trailing edge of the wing is straight, facilitating the installation and rotation of the ailerons.

[0023] The aileron adopts a linkless design, and there are no exposed structural members outside the wing surface to ensure the integrity and smoothness of the upper and lower wing surfaces.

[0024] The leading edge of the aileron is embedded in the wing surface to ensure smooth airflow. Brief Description of the Drawings

[0025] Figure 1 An isometric view of the whole machine of a small long-endurance UAV with two engines according to an embodiment of the present invention.

[0026] Figure 2Side view of the whole machine of a small long-endurance UAV with dual engines according to an embodiment of the present invention.

[0027] Figure 3 Top view of the whole machine of a small long-endurance UAV with dual engines according to an embodiment of the present invention.

[0028] Figure 4 Another isometric view of the whole machine of a small long-endurance UAV with dual engines according to an embodiment of the present invention.

[0029] Figure 5 Another isometric view of the whole machine of a small long-endurance UAV with dual engines according to an embodiment of the present invention.

[0030] Figure 6 Partial view of the front fuselage of a small long-endurance UAV with dual engines according to an embodiment of the present invention.

[0031] Figure 7 Partial view of the rear fuselage of a small long-endurance UAV with dual engines according to an embodiment of the present invention.

[0032] Figure 8 Partial view of the ejection rack of a small long-endurance UAV with dual engines according to an embodiment of the present invention.

[0033] Figure 9 Another partial view of the front fuselage of a small long-endurance UAV with dual engines according to an embodiment of the present invention.

[0034] Figure 10 Another partial view of the rear fuselage of a small long-endurance UAV with dual engines according to an embodiment of the present invention. Specific implementation

[0035] Now, the embodiments of the present invention will be described by way of examples.

[0036] As Figure 1 - Figure 10 shown, the present invention adopts a conventional wing + normal tail layout. The wing has a relatively large aspect ratio and good lift-to-drag characteristics. The normal tail layout is the most conventional and can provide good longitudinal and directional handling and stability characteristics. The structure is simple and reliable, and the processing, manufacturing and assembly are relatively simple, reducing costs. The wing-mounted dual-engine power method is adopted, with two fuel engines, and a special reducer system is designed to drive high-performance carbon fiber propellers to provide forward thrust. The fuel engines are configured with an on-board generator system, which can provide sufficient power supply for on-board equipment and mission payloads.

[0037] The small long-endurance UAV with dual engines according to an embodiment of the present invention is as shown in the appendix Figure 1As shown in the figure, it includes: fuselage 1, wing 2, horizontal tail 3, and power plant 4.

[0038] (1) Aerodynamic shape optimization design

[0039] The UAV of the present invention has been fully and reasonably optimized in aerodynamic shape design, which can effectively reduce the air resistance during cruise flight, specifically as follows:

[0040] 1) The fuselage shape adopts a streamlined design with low flight resistance. The nose is a blunt body to ensure sufficient internal space of the fuselage. The tail converges according to the streamlined contour, which can effectively reduce the pressure drag of the fuselage part.

[0041] 2) The wing adopts a large aspect ratio. The leading edge is an S-shaped curve. The central wing 201 is integrally designed with the fuselage 1 to reduce the interference drag between components; it converges at the wingtip small wing 203 to effectively reduce the induced drag of the wing 2; the trailing edge of the wing 2 is straight, which is convenient for the installation and rotation of the aileron 204.

[0042] The aileron 204 adopts a non-link design. There are no exposed structural parts outside the wing surface to ensure the integrity and smoothness of the upper and lower wing surfaces. The leading edge of the aileron 204 is inlaid with the wing surface to ensure smooth airflow and reduce aerodynamic drag.

[0043] (2) High-reliability and easy-maintenance structural design

[0044] The components of the whole aircraft are mainly divided into fuselage 1, wing 2, horizontal tail 3, and power plant 4.

[0045] The wing 2 is a typical double-beam structural design, including central wing 201, outer wing section 202, wingtip small wing 203, and aileron 204; the power plant 4 is suspended in front of the central wing 201. The suspension structure 401 is made of titanium alloy and aluminum-lithium alloy, which can effectively reduce the structural weight while ensuring the connection strength and stiffness; the suspension metal structure 401 and the central wing 201 are co-cured and integrally formed, significantly reducing the structural weight of the connecting parts at this place; the central wing 201 and the fuselage 1 are connected up and down, and a total of 6 second bolts 110 are used for fastening, and the local skin and structure are thickened and strengthened; in addition, a metal structural part 501 connected to the ejection rack 5 is arranged at the lower part of the central wing 201 to realize the fixation and release of the UAV on the ejection rack 5.

[0046] The fuselage is divided into a front fuselage 101 and a rear fuselage 102, and the two are sleeved through an innovatively designed connecting frame section 109 ( Figure 6 ) The outer shape of the connecting frame section 109 is different up and down, with a foolproof design to ensure the quick and reliable connection of the fuselage in the field; the front fuselage and the rear fuselage are fastened by six second bolts 110 up, down, left, and right. The second bolts 110 are operated through the parachute compartment space at the rear of the front fuselage, without adding additional process and maintenance covers to the fuselage, improving the structural load-bearing efficiency, and ensuring sufficient connection strength and stiffness under the condition of a lightweight structure.

[0047] Three large opening areas are provided at the upper part of the front fuselage 101, namely the front equipment hatch 103, the middle wing mounting surface, and the rear parachute hatch 104. Among them, for the front equipment hatch 103, it is required that the antenna electromagnetic waves inside the fuselage are not blocked or shielded. Therefore, it is formed by a sandwich structure of wave-transparent fiberglass + PMI rigid foam. The rear parachute hatch 104 is formed by carbon fiber molding. It is closed and controlled with the fuselage 101 by a rear torsion spring hinge + a front servo 111. When the hatch needs to be opened, the front servo 109 deflects 90 degrees, and the rear parachute hatch 104 automatically bounces backward under the action of the rear torsion spring, facilitating the release of the internal parachute.

[0048] A small maintenance hatch 105 is provided at the lower part of the rear fuselage 102, facilitating the installation and debugging of airborne equipment; the rear fuselage 105 and the vertical tail 106 are integrally formed, with fewer frames and ribs inside, improving the structural efficiency and reducing the structural weight; in addition, the tip of the rudder 107 extends forward to the leading edge of the vertical tail 106, forming an aerodynamic compensation structure, reducing the hinge moment and load of the rudder 107; a rudder 107 is provided at the rear of the vertical tail 106 and is jointly controlled by two servos 108, improving the system reliability and redundancy.

[0049] The horizontal tail adopts a full-moving horizontal tail design, and the rotating shaft is set at a position close to the root rib, effectively reducing the hinge moment of the horizontal tail; the rotating shaft uses a high-performance wound carbon fiber thin-walled pipe, with an obvious weight reduction effect; the control servo of the horizontal tail controls the rotating shaft through a rocker arm, driving the left and right horizontal tails to rotate; the servo is installed at the rear of the rear fuselage, and there are no electrical components, control mechanisms, and cables on the horizontal tail, effectively reducing the system weight and improving the longitudinal handling and stability characteristics of the whole aircraft.

[0050] The beneficial effects of the present invention include:

[0051] 1) The fuselage shape of the present invention adopts a streamlined design with small flight resistance. The nose is a blunt body, ensuring sufficient internal space of the fuselage. The tail converges according to the streamlined contour, which can effectively reduce the pressure drag of the fuselage part.

[0052] 2) The wing of the present invention has a large aspect ratio, the leading edge is an S-shaped curve, and the central wing is integrally designed with the fuselage, reducing the interference drag between components; it converges at the winglets, effectively reducing the induced drag of the wing.

[0053] 3) The aileron of the present invention adopts a non-link design, with no exposed structural parts outside the wing surface, ensuring the integrity and smoothness of the upper and lower wing surfaces. The leading edge of the aileron is embedded in the wing surface, ensuring smooth airflow and reducing aerodynamic drag.

[0054] 4) The present invention adopts a normal tail layout, which can provide good longitudinal and directional handling and stability characteristics; the structure is simple and reliable, and the processing, manufacturing, and assembly are relatively simple, reducing costs.

[0055] 5) The present invention adopts a full-aircraft structural design with lightweight and high structural efficiency. For each connecting metal part, high-strength titanium alloy and aluminum-lithium alloy are used for numerical control machining to effectively reduce weight while ensuring structural strength and stiffness; redundant backups are provided for the manipulation of moving parts to improve reliability; a large number of co-cured structures are adopted for composite parts, significantly reducing the structural parts of the whole aircraft and the difficulty of outfield operation and maintenance.

[0056] 6) The horizontal tail of the unmanned aircraft of the present invention adopts a full-moving horizontal tail design, effectively reducing the hinge moment of the horizontal tail; the rotating shaft adopts a high-performance wound carbon fiber thin-walled pipe, with obvious weight reduction effect and improving the longitudinal handling and stability characteristics of the whole aircraft.

Claims

1. A small long-endurance unmanned aerial vehicle with dual engines, characterized in that Including: Fuselage (1), wing (2), horizontal tail (3), power plant (4), Wherein: The fuselage is designed with a streamlined shape with low flight resistance, and the nose is a blunt body. The fuselage includes a front fuselage (101) and a rear fuselage (102). The front fuselage (101) and the rear fuselage (102) are sleeved through a connecting frame section (109). The two front and rear connecting frame sections (109) are fastened by four first bolts (114). The upper semi-circular groove (112) of the connecting frame section (109) is smaller in external dimension than the lower semi-circular groove (113) to prevent the installer from installing the front fuselage (101) and the rear fuselage (102) upside down, ensuring the quick and reliable installation and connection of the front fuselage (101) and the rear fuselage (102) in an outdoor site. Three large opening areas are provided on the upper part of the front fuselage (101): a front equipment hatch (103), a middle wing mounting surface (115), and a rear parachute hatch (104). The front equipment hatch (103) is formed by a sandwich structure of wave-transparent fiberglass and polymethacrylimide foam to avoid shielding and / or screening of the antenna electromagnetic waves inside the fuselage. The rear parachute hatch (104) and the front fuselage (101) are closed and controlled by a rear torsion spring hinge plus a front servo (111). When the rear parachute hatch (104) needs to be opened, the front servo deflects 90 degrees, so that the rear parachute hatch (104) automatically bounces backward under the action of the rear torsion spring, facilitating the release of the internal parachute. A small maintenance hatch (105) is provided at the lower part of the rear fuselage (102) to facilitate the installation and debugging of on-board equipment. The rear fuselage (102) and the vertical tail (106) are integrally formed, thus reducing the setting of internal frames and ribs. A rudder (107) is provided at the rear of the vertical tail (106). The tip of the rudder (107) extends forward to the leading edge of the vertical tail (106) to form an aerodynamic compensation structure to reduce the hinge moment and / or load of the rudder (107). The rudder is jointly controlled by two servos (108) to improve reliability. The front fuselage (101) and the central wing (201) are fastened by multiple second bolts (110) located respectively above, below, left, and right. The second bolts (110) are installed and fastened through the lower parachute compartment space (116) of the rear parachute hatch (104), without adding additional processes and maintenance hatches to the fuselage. The wing is of a double-beam structure, including a central wing (201), an outer wing section (202), winglets (203), and ailerons (204). The power plant (4) is suspended in front of the central wing through a suspension structure (401). The suspension structure (401) and the central wing (201) are integrally co-cured and formed to reduce the structural weight; the central wing (201) is connected to the fuselage up and down. A metal structural member (501) connected to the ejection rack (5) is provided at the lower part of the central wing (201) to realize the fixing and release of the UAV on the ejection rack. The wing has a large aspect ratio, and the leading edge is an S-shaped curve. The central wing (201) of the wing is integrated with the fuselage. The wing converges at the winglets (203) to reduce the induced drag of the wing. The trailing edge of the wing is straight, facilitating the installation and rotation of the aileron (204). The aileron (204) adopts a linkless design, without exposed structural components outside the wing surface, to ensure the integrity and smoothness of the upper and lower wing surfaces. The leading edge of the aileron (204) is embedded in the wing surface to ensure smooth airflow.

2. The small long-endurance unmanned aerial vehicle with dual engines according to claim 1, characterized in that: The rear parachute compartment cover (104) is formed by carbon fiber compression molding.

3. The small long-endurance unmanned aerial vehicle with dual engines according to claim 1, characterized in that: The suspension structure (401) is made of titanium alloy and aluminum-lithium alloy to effectively reduce the structural weight while ensuring the connection strength and stiffness.

4. The small long-endurance unmanned aerial vehicle with dual engines according to claim 1, characterized in that: The front fuselage (101) and the central wing (201) are fastened by six second bolts (110) in the up, down, left and right directions.

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