Coaxial double-paddle paperboard fixed wing unmanned aerial vehicle

Abstract

The utility model relates to a coaxial double-paddle paperboard fixed-wing unmanned aerial vehicle which comprises a vehicle body and wings fixed at the middle upper part of the vehicle body, the vehicle body comprises two round rods, an engine mounting frame is arranged between the front ends of the two round rods, a forward rotation engine is fixed at the front side of the engine mounting frame, and a reverse rotation engine is fixed at the rear side of the engine mounting frame. The axes of the forward rotation engine and the reverse rotation engine coincide, a front propeller is fixed to an output shaft of the forward rotation engine, a rear propeller is fixed to an output shaft of the reverse rotation engine, and the pull-down angle and the pull-down angle of the two engines are both 2 degrees. The utility model has the advantages that the two engines are respectively provided with the positive and negative paddles, and the two engines have opposite rotating directions and are used for counteracting the counter torque of the engines and the paddles. And the unmanned aerial vehicle flies more stably. The double engines are coaxially installed, especially when one set of power equipment is damaged, the other set of power equipment works independently, a tension line is not changed, the flight state is not affected at all, normal flight can still be achieved, and the flight safety is guaranteed to the maximum extent.

Description

Technical Field

[0001] This utility model relates to a fixed-wing drone, and more particularly to a coaxial dual-propeller cardboard fixed-wing drone. Background Technology

[0002] A fixed-wing unmanned aerial vehicle (UAV) is an aircraft that uses a fixed wing to generate lift and is controlled by a wireless remote controller or computer commands.

[0003] Currently, small fixed-wing drones are widely used for aerial surveying, inspection, performances, disposable target drones, teaching, beginner flight skill practice, and medium payload applications. However, these small fixed-wing drones all use a single propeller. Furthermore, components such as the fuselage and wings are made of balsa wood veneer and high-strength EPO foam. The production processes for balsa wood veneer and high-strength EPO foam are complex and costly, making them impossible for ordinary users to manufacture themselves. Furthermore, damage during use can significantly increase operating costs.

[0004] Furthermore, if a single-rotor fixed-wing UAV experiences a power system failure during flight, it can crash. Additionally, the fuselage of a single-rotor UAV needs to overcome the effects of counter-torque to improve flight stability. Patent application number 2016200024636, entitled "A Fixed-Wing UAV Using Coaxial Tandem Twin Engines," discloses a coaxial tandem twin-engine design. While this solves the problem of single-rotor UAVs being unable to restart in mid-air, the rotor blades are positioned on opposite sides of the wing. This improves the UAV's safety to some extent, but the large distance between the two power systems poses significant safety risks. Firstly, if neither engine is equipped with pull-down or pull-up angles, the engine's rotational torque will cause the UAV to constantly exhibit a pitching and left-tilting tendency. Even with flight control, this pitching and left-tilting tendency will significantly reduce the aircraft's wind resistance, greatly increasing the risk of loss of control. Secondly, installing both right and down-angle engines on the front-mounted engines can alleviate the tendency to pitch up and to the left; however, a new problem arises: the thrust lines of the two engines cannot align. This significantly reduces the aircraft's power efficiency and worsens its handling performance, making the aircraft extremely difficult to control. Thirdly, installing both down-angle and right-angle engines on both the front and rear engines, due to the significant distance between them (greater than the wing width) and their placement along the wing centerline, inevitably results in the thrust lines of the two engines not aligning. The problems of low power efficiency and poor handling persist simultaneously.

[0005] Therefore, how to ensure that both engines have pull-up and pull-down angles and that their thrust lines coincide, so that when one power unit is damaged, the other power unit can operate independently without changing the thrust line, thus ensuring that the flight status is completely unaffected and that normal flight can still be carried out, thereby maximizing flight safety, is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] To solve the above-mentioned technical problems, this utility model provides a coaxial dual-propeller cardboard fixed-wing UAV. The purpose is to install two engines on the coaxial axis to ensure that when one power unit is damaged, the other power unit can work independently and still fly normally.

[0007] To achieve the above objectives, this utility model discloses a coaxial dual-propeller cardboard fixed-wing unmanned aerial vehicle (UAV), comprising a fuselage, a wing fixed to the upper middle part of the fuselage, the fuselage consisting of two round rods, an engine mounting bracket between the front ends of the two round rods, a forward-rotating engine fixed to the front side of the engine mounting bracket, a reverse-rotating engine fixed to the rear side of the engine mounting bracket, the axes of the forward-rotating and reverse-rotating engines coinciding, a front propeller fixed to the output shaft of the forward-rotating engine, a rear propeller fixed to the output shaft of the reverse-rotating engine, the pull-down angle and pull-up angle of both engines being 2 degrees, and the thickness of the engine mounting bracket being less than half the width of the wing.

[0008] The rod is made of cardboard rolled into a cylinder.

[0009] The wing material is a cardboard folded into an upward-convex arc shape. A reinforcing rod is fixed along the length of the inner wall of the wing. The reinforcing rod is located at one-quarter of the leading edge of the wing and is made of carbon fiber.

[0010] The inner wall of the wing is provided with multiple ribs arranged in parallel, and the ribs are made of cardboard.

[0011] The arc shape of the top surface of the rib is the same as the arc shape of the inner wall of the wing.

[0012] The width of the two middle ribs is the same as the width of the two round rods, and the bottom of the ribs is fixedly connected to the round rods.

[0013] The outer side of the rear circular rod of the wing is provided with an aileron.

[0014] The rear of the fuselage is provided with a horizontal stabilizer, a vertical stabilizer is provided on the center line of the horizontal stabilizer, a rudder is provided behind the vertical stabilizer, and an elevator is provided behind the horizontal stabilizer.

[0015] The horizontal stabilizer, vertical stabilizer, rudder, and elevator are made of cardboard.

[0016] The fuselage length is 0.7 meters to 3 meters, and the wing length is 0.7 meters to 3 meters.

[0017] Advantages and effects of this utility model:

[0018] This invention features two engines mounted on opposing propellers, with the two engines rotating in opposite directions to counteract the reversing torque of the engines and propellers. This results in more stable flight for the drone. The coaxial mounting of the two engines ensures that even if one power system fails, the other can operate independently without altering the thrust line, maintaining flight stability and maximizing safety. The fuselage and other materials utilize an all-cardboard structure, making it lightweight, rigid, and with moderate toughness for a small to medium-sized fixed-wing drone. Furthermore, it is extremely inexpensive and easy to manufacture. It can be widely used for aerial surveying, inspection, performances, disposable target drones, teaching, beginner flight skill practice, and medium-load applications. The two engines are mounted on a single mounting base, ensuring consistent thrust lines. Whether both power systems are operating simultaneously or only one power system is operating, there is no tendency for the drone to pitch up or to the left, perfectly maintaining its flight attitude and thus enhancing safety. Attached Figure Description

[0019] Figure 1 This is the front view of this utility model.

[0020] Figure 2 This is a side view of the present invention.

[0021] Figure 3 This is a top view of the present invention.

[0022] Figure 4 yes Figure 2 A schematic diagram of the pull-down angle of the two engines.

[0023] Figure 5 yes Figure 3 A schematic diagram of the right-hand pull angle of the two engines.

[0024] Figure 6 This is a perspective view of the wing of this utility model from below.

[0025] In the diagram: 1. Front propeller; 2. Forward-rotating engine; 3. Engine mounting bracket; 4. Reverse-rotating engine; 5. Rear propeller; 6. Aileron; 7. Wing; 8. Pull-down angle; 9. Fuselage; 10. Horizontal stabilizer; 11. Vertical stabilizer; 12. Rudder; 13. Elevator; 14. Right pull-up angle; 15. Reinforcing bar; 16. Wing rib; 17. Pull line; 18. UAV longitudinal axis; 19. Landing gear. Detailed Implementation

[0026] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0027] As shown in the figure, this utility model discloses a coaxial dual-propeller cardboard fixed-wing UAV, including a fuselage 9 and a wing 7 fixed to the front middle part of the fuselage 9. The wing 7 is made of cardboard folded into an upward convex arc shape. A reinforcing rod 15 is fixed along the length of the inner wall of the wing and is located at one-quarter of the leading edge of the wing. The reinforcing rod 15 is made of carbon fiber. The fuselage 9 consists of two round rods made of cardboard rolled into cylinders. An engine mounting bracket 3 is provided between the front ends of the two round rods. A forward-rotating engine 2 is fixed to the front side of the engine mounting bracket 3, and a reverse-rotating engine 4 is fixed to the rear side of the engine mounting bracket 3. The axes of the forward-rotating engine 2 and the reverse-rotating engine 4 coincide. A front propeller 1 is fixed on the output shaft of the forward-rotating engine 2, and a rear propeller 5 is fixed on the output shaft of the reverse-rotating engine 4. The pull-down angle 8 and the pull-up angle 14 of both engines are 2 degrees. The thickness of the engine mounting bracket 3 is less than half the width of the wing 7 to ensure that when the pull-down angle 8 and the right pull-up angle 14 are present at the same time, the thrust lines of the two engines coincide and the two engines do not deviate too much from the centerline of the wing.

[0028] Multiple ribs 16 are arranged in parallel on the inner wall of the wing 7. In this embodiment, there are 6 ribs 16. The material of the ribs 16 is cardboard, and the top surface arc of the ribs 16 is the same as the arc of the inner wall of the wing 7, which facilitates the fixing of the top surface of the ribs 16 to the inner wall of the wing 7.

[0029] The width of the two middle ribs 16 is the same as the width of the two round rods, and the bottom of the ribs 16 is fixedly connected to the round rods.

[0030] Ailerons 6 are provided on the outer side of the round rod at the rear end of wing 7.

[0031] A horizontal stabilizer 10 is located at the rear of the fuselage 9. A vertical stabilizer 11 is located on the center line of the horizontal stabilizer 10. A rudder 12 is located behind the vertical stabilizer 11. An elevator 13 is located behind the horizontal stabilizer 10. The horizontal stabilizer 10, vertical stabilizer 11, rudder 12, and elevator 13 are made of cardboard. The landing gear 19 is installed under the fuselage 9, in the same position as the landing gear of existing fixed-wing UAVs.

[0032] The fuselage length of a fixed-wing UAV is 0.7 meters to 3 meters, and the wing length is 0.7 meters to 3 meters. In this embodiment, the fuselage and wing length are 1.5 meters.

[0033] The cardboard specification of this utility model is 4mm thick 5-layer BE corrugated cardboard.

[0034] The table below compares drones made of cardboard with those made of balsa wood veneer and high-strength foam.

[0035] The flight parameters and fuselage cost are compared in the table below (1-meter wingspan):

[0036]

[0037] Conclusion: Cardboard drones are low-cost, easy to manufacture, consume less power than drones with the same wingspan, have a slightly faster stall speed and cruise speed than drones made of traditional materials. In the field of small to medium-sized fixed-wing drones (0.7-3 meters wingspan), they can replace drones made of traditional materials.

[0038] This utility model adopts a high-wing monoplane and traditional T-tail layout, with a front-mounted propeller and a rear tricycle landing gear. The fuselage is made of all-cardboard construction, which is lightweight, has good rigidity, and moderate toughness for a small to medium-sized fixed-wing UAV. Moreover, it is extremely inexpensive to manufacture, and the processing steps are simple and fast.

[0039] By placing the two engines close together and positioning them in the forward position, it is possible to simultaneously pull down and pull to the right at small angles, each angle being 2 degrees. Figure 4 As shown, pull-down angle 8 is the angle between the pull line 17 and the longitudinal axis 18 of the drone; as Figure 5 As shown, the right pull angle 14 is the angle between the pull line 17 and the longitudinal axis 18 of the UAV. Both engines are mounted on a single engine mount 3, with the pull lines 17 always coinciding. Whether both power systems are operating simultaneously or only one power system is operating in isolation due to a malfunction, there will be no pitching or rolling tendency, perfectly maintaining the flight attitude and thus improving aircraft safety.

[0040] The working principle of this invention is as follows: When the UAV starts, the two engines rotate, driving the two propellers to rotate. Both propellers simultaneously exhaust air towards the tail, propelling the aircraft forward until the wheels leave the ground, entering flight mode. Because the engines operate at synchronized speeds (forward and reverse rotation), and the two propellers have the same pitch, the torque is canceled out, completely eliminating the influence of counter-torque. This results in smoother flight, more timely and accurate control response, and significantly improved flight path precision and safety. Furthermore, the dual engines are coaxially mounted, with both engine shafts on the same straight line. This ensures that even if one power system fails, the thrust line remains unchanged when the other power system operates independently, and flight attitude and control precision are unaffected, thus greatly improving flight safety—a feature unmatched by conventional fixed-wing UAVs. Moreover, the engines are ordinary brushless engines, requiring no special manufacturing, readily available materials, a wide range of models, and low cost. Apart from the aforementioned coaxial dual-propeller power system, the other control procedures and principles are completely consistent with conventional fixed-wing UAVs and will not be elaborated upon here.

[0041] Therefore, this invention is suitable for various applications such as aerial surveying, inspection, performance, and medium-payload drones. It is particularly suitable for single-use drones, such as target drones for shooting training and reconnaissance and strike drones. It is also the preferred model for popularizing drone knowledge. Its application prospects are very broad.

Claims

1. A coaxial dual-propeller cardboard fixed-wing unmanned aerial vehicle, comprising a fuselage and a wing fixed to the upper middle part of the fuselage, characterized in that... The fuselage consists of two round rods, with an engine mounting bracket between the front ends of the two rods. The forward-rotating engine is fixed to the front side of the engine mounting bracket, and the reverse-rotating engine is fixed to the rear side of the engine mounting bracket. The axes of the forward-rotating and reverse-rotating engines coincide. A front propeller is fixed on the output shaft of the forward-rotating engine, and a rear propeller is fixed on the output shaft of the reverse-rotating engine. The pull-down angle and pull-up angle of both engines are 2 degrees. The thickness of the engine mounting bracket is less than half the width of the wing.

2. The coaxial dual-propeller cardboard fixed-wing UAV according to claim 1, characterized in that... The rod is made of cardboard rolled into a cylinder.

3. The coaxial dual-propeller cardboard fixed-wing UAV according to claim 1, characterized in that... The wing material is a cardboard folded into an upward-convex arc shape. A reinforcing rod is fixed along the length of the inner wall of the wing. The reinforcing rod is located at one-quarter of the leading edge of the wing and is made of carbon fiber.

4. A coaxial dual-propeller cardboard fixed-wing UAV according to claim 3, characterized in that... The inner wall of the wing is provided with multiple ribs arranged in parallel, and the ribs are made of cardboard.

5. A coaxial dual-propeller cardboard fixed-wing UAV according to claim 4, characterized in that... The arc shape of the top surface of the rib is the same as the arc shape of the inner wall of the wing.

6. A coaxial dual-propeller cardboard fixed-wing UAV according to claim 4 or 5, characterized in that... The width of the two middle ribs is the same as the width of the two round rods, and the bottom of the ribs is fixedly connected to the round rods.

7. A coaxial dual-propeller cardboard fixed-wing UAV according to claim 1, 3 or 4, characterized in that... The outer side of the rear circular rod of the wing is provided with an aileron.

8. A coaxial dual-propeller cardboard fixed-wing UAV according to claim 1, characterized in that... The rear of the fuselage is provided with a horizontal stabilizer, a vertical stabilizer is provided on the center line of the horizontal stabilizer, a rudder is provided behind the vertical stabilizer, and an elevator is provided behind the horizontal stabilizer.

9. A coaxial dual-propeller cardboard fixed-wing UAV according to claim 8, characterized in that... The horizontal stabilizer, vertical stabilizer, rudder, and elevator are made of cardboard.

10. A coaxial dual-propeller cardboard fixed-wing UAV according to claim 1, characterized in that... The fuselage length is 0.7 meters to 3 meters, and the wing length is 0.7 meters to 3 meters.

Images