A passive flapping wing device

Abstract

This invention discloses a passive flapping-wing device, belonging to the field of aviation technology. It includes a fuselage and a flapping wing movably connected to the fuselage. The fuselage controls the flapping wing to reciprocate its pitch angle or cyclically change the upper and lower convex surfaces, promoting the exchange of pressure between the upper and lower surfaces in the face of an incoming airflow. This drives the flapping wing to generate mechanical energy, forming a flapping-wing generator, or combines with the reaction force of the swept-back oscillation to generate lift and thrust, thus forming a flapping-wing aircraft. This invention uses a non-fixed flapping wing surface, utilizing the exchange of pressure between the upper and lower surfaces in the face of an incoming airflow to cause the flapping wing to passively flap in response to pressure changes, achieving the construction of a large flapping-wing device using conventional structural materials.

Description

Technical Field

[0001] This invention belongs to the field of aviation technology, and specifically relates to a flapping wing device. Background Technology

[0002] A flapping wing is a structural device that mimics bird flight. Birds generate lift and propulsion by flapping their wings, making it more efficient and flexible than a fixed wing. Since ancient times, people have dreamed of flying in the sky like birds, but until now, it has been impossible to achieve the same flexible and efficient use of flapping wings. In particular, large flapping wings are limited by technological bottlenecks such as high-strength materials and structures, making it impossible to actively promote flight by flapping the wings with a fixed wing surface. Summary of the Invention

[0003] In order to solve the above-mentioned problems or deficiencies in the prior art, the present invention discloses a passive flapping wing device, which uses a flapping wing that reciprocates by deflecting the pitch angle or cyclically changing the upper and lower convex wing surfaces. In the face of the wind, the pressure on the upper and lower wing surfaces is cyclically exchanged, and the flapping motion generates power, thus realizing the construction of a large flapping wing device using conventional structural materials.

[0004] The flapping wing device of the present invention is achieved through the following technical solution: a passive flapping wing device, comprising a fuselage and flapping wings movably connected to the fuselage, wherein the fuselage controls the flapping wings to reciprocate to deflect the pitch angle or to cyclically change the upper and lower convex wing surfaces, thereby promoting the cyclical exchange of pressure between the upper and lower wing surfaces in the face of the airflow, thereby driving the flapping wings to flap and generate mechanical energy to form a flapping wing generator, or combining the reaction force of the sweeping swing to generate lift thrust to form a flapping wing aircraft.

[0005] Preferably, the flapping wing consists of a first wing section at the wing root and a second wing section at the wingtip, connected by a secondary rudder to form a double-convex wing or a symmetrical wing. The first wing section is provided with a front sparb, a rear sparb, and a middle sparb. The front and rear spars are provided with a main rudder at their front ends, which are connected to the fuselage, and the rear ends are provided with a secondary rudder, which is connected to the second wing section. The front ends of the middle sparb are provided with suspensions on both the upper and lower sides, which are connected to the fuselage, and the rear ends are provided with hinges, which are connected to the second wing section. The main rudder uses the suspensions as a fulcrum to push and pull, driving the pitch angle of the first wing section to cyclically swing. The flapping wing is driven by the pressure exchange between the upper and lower wing surfaces generated by the airflow.

[0006] Preferably, the front end of the middle beam is provided with a telescopic transmission rod, the rear end of the transmission rod is provided with a crank rocker mechanism through a bushing, and the rear end is provided with a guide rail, which connects the flapping wing to the fuselage via the servo motor and suspension. It is also connected to a kinetic energy recovery device through the crank rocker mechanism to form a flapping wing generator, which recovers the mechanical energy of the flapping wing driven by the wind to generate electricity.

[0007] Preferably, the second wing section has a drive component obliquely arranged from the leading edge of the wingtip to the trailing edge of the wing root, which drives the second wing section to deflect the pitch and sweep angles to control its attitude, improve the lift of the first wing section, and generate propulsion by utilizing the reaction force of the sweeping swing.

[0008] Preferably, the flapping wing includes a front spars, a rear spars, wing ribs, and a skin. The front spars and rear spars form arc-shaped wing spars that can deflect forward and backward along the wingspan direction, and the wing ribs form arc-shaped wing ribs that can flip up and down along the upper arc direction. The front spars and rear spars are provided with multiple worm gear transmission mechanisms, which are movably connected to the wing ribs through universal couplings and covered with skin to form a flapping wing with variable upper and lower convex wing surfaces. The front spars and rear spars are provided with drive components on the inner side of the wing root end, and suspensions are provided on the upper and lower sides of the wing root end to movably connect the flapping wing to the fuselage. The drive components drive the front spars and rear spars to deflect backward and swing back and forth synchronously, and drive the wing ribs to flip up and down through the worm gear transmission mechanism to realize the back and forth change of the upper and lower concave and convex wing surfaces, promote the cyclic exchange of pressure generated on the upper and lower wing surfaces by the airflow to drive the flapping wing to flap, and generate propulsion by the reaction force of the sweepback.

[0009] Preferably, the front and rear beams are connected by a crossbeam and a telescopic transmission rod is provided on the inner side of the front end. The transmission rod is provided with a crank rocker mechanism at the tail end and a guide rail at the tail end. The flapping wing is movably connected to the fuselage by the servo motor and suspension. The flapping wing generator is connected to the kinetic energy recovery device through the crank rocker mechanism to recover the mechanical energy of the flapping wing driven by the wind to generate electricity.

[0010] Preferably, the worm gear transmission mechanism is provided with a deformable material forming a smooth connecting skin for the leading and trailing edges of the flapping wing; the wing ribs are fitted with rollers that pass between the skins of the upper and lower wing surfaces, and the flexible connection forms a variable outward convex wing surface; the skin is a flexible skin with a certain elasticity to enhance surface tension, and together with the universal coupling, it forms a balanced tension of the wing ribs, strengthening the overall structure of the flapping wing.

[0011] Preferably, the kinetic energy recovery device consists of a braking mechanism and an electrical energy recovery device, and the aircraft is equipped with a tail fin and a propeller to form a flapping-wing aircraft. It can recover the kinetic energy of the incoming airflow during updraft or descent to generate electricity and store energy to increase the range. The kinetic energy recovery device can control the flapping wing to a fixed-wing mode through the braking mechanism, so as to adapt to different flight environments and improve flight efficiency.

[0012] The advantages of this invention compared to the prior art are: by using a non-fixed flapping wing surface and utilizing the pressure of the upper and lower wing surfaces to alternate back and forth with the airflow, the flapping wing is caused to produce a passive flapping motion as the pressure changes, thus realizing the construction of a large flapping wing device using conventional structural materials. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the first embodiment of the passive flapping wing device of the present invention.

[0014] Figure 2 This is a schematic diagram of the structure of the first embodiment of the passive flapping wing device of the present invention.

[0015] Figure 3This is a schematic diagram of a second embodiment of the passive flapping wing device of the present invention.

[0016] Figure 4 This is a schematic diagram of the structure of the second embodiment of the passive flapping wing device of the present invention. Detailed Implementation

[0017] To make the technical solution of the present invention clearer, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0018] The embodiments described below with reference to the accompanying drawings are merely illustrative examples of the present invention and are not intended to limit the present invention in any way. Any modifications or equivalent changes made by those skilled in the art without departing from the scope of the present invention shall fall within the scope of the present invention.

[0019] Figure 1 , Figure 2 This invention illustrates a first embodiment of a flapping-wing aircraft comprising a fuselage and a flapping-wing body with a variable pitch angle. The flapping-wing body consists of a first wing section with a larger area at the wing root for main lift and a second wing section with a smaller area at the wingtip for attitude control, connected by a secondary rudder 4 and hinges to form a symmetrical airfoil. The first wing section has a front sparb 1, a rear sparb 2, and a center sparb 3. The front ends of the front sparb 1 and rear sparb 2 have a main rudder 5, composed of hydraulic cylinders, connected to the fuselage via hinges, while the rear ends have a secondary rudder 4, composed of cylinders, connected to the second wing section via hinges. The front end of the center sparb 3 has a suspension 6, composed of shock absorbers on the upper and lower sides, connected to the fuselage via hinges, while the rear end has a suspension 6 connected to the second wing section via hinges with certain damping and rigidity, thus strengthening the structure of the flapping-wing body. The two main rudders 5 of the front and rear beams drive the pitch angle of the first wing section to swing cyclically with the suspension 6 as the fulcrum. This causes the pressure on the upper and lower wing surfaces to be exchanged cyclically, which in turn drives the flapping wing body to flap. The reaction force generates lift and thrust. Moreover, the passive flapping method can greatly reduce the pressure on the wing surface and reduce the high requirements for the strength of the flapping wing structure and materials.

[0020] like Figure 2As shown, the front end of the central beam 3 is fixedly connected to the transmission rod 7. The tail end of the transmission rod 7 is equipped with a bushing and a connecting shaft on the bushing, which is movably connected to the rocker arm of the crank-rocker mechanism 8, ensuring flexible transmission when the flapping wing body deflects its pitch angle. The tail end of the transmission rod 7 is equipped with a spring rod that is movably connected to the guide rail 10 via rollers, allowing for automatic extension and retraction for stable connection. This controls the reciprocating motion of the flapping wing body in the vertical direction and, together with the main rudder 5 and suspension 6, movably connects the flapping wing body to the fuselage, forming a lever transmission mechanism to support the flapping motion. The crank-rocker mechanism 8 is connected to a kinetic energy recovery device 9, consisting of a generator and a battery, via a clutch gearbox. During updrafts and descents, the flapping wing aircraft uses the mechanical energy generated by the flapping motion against the airflow to drive the crank-rocker mechanism 8 through the transmission rod 7, which in turn drives the kinetic energy recovery device 9 to generate electricity and store energy to increase range. The kinetic energy recovery device 9 is also equipped with a braking device to control the asynchronous flapping motion of the flapping wing body, which, combined with the auxiliary rudder 4, actively controls the sweep angle of the second wing section, promoting the flight attitude control of the flapping wing aircraft.

[0021] like Figure 1 , Figure 2 As shown, a drive component 11, consisting of a cylinder guide rail and a counterweight, is obliquely arranged from the leading edge of the wingtip to the trailing edge of the wing root on the second wing section. During the first half-cycle when the main rudder 5 drives the first wing section to a downward angle of attack, the piston rod of the cylinder of the auxiliary rudder 4, located on the rear spars 2, extends to control the second wing section to sweep forward. Simultaneously, the drive component 11 drives the counterweight to slide towards the leading edge of the wingtip due to centrifugal force, driving the second wing section to accelerate the downward movement of the first wing section to a downward angle of attack. During the second half-cycle when the servo 5 drives the first wing section to an upward angle of attack, the piston rod of the cylinder of the auxiliary rudder 4, located on the front spars 1, extends to control the second wing section to sweep backward. At the same time, the drive component 11 drives the counterweight to slide towards the trailing edge of the wing root due to centrifugal force, utilizing the reaction force of the sweep to generate propulsion, and driving the second wing section to accelerate the upward movement of the first wing section to an upward angle of attack. The auxiliary rudder 4 and the drive component 11 can also control the second wing section to generate a pitch angle opposite to that of the first wing section, reducing the flapping amplitude of the first wing section and increasing the flapping frequency, thus improving attitude control.

[0022] like Figure 1 As shown, the flapping-wing aircraft of this embodiment of the invention mimics the characteristics of a bird's glider, forming a large aspect ratio airfoil. It achieves flapping motion by using a tail fin at the rear of the fuselage to control direction and altitude, and by using a thruster 16 to promote airflow and generate pressure on the wing surface. The flapping-wing aircraft of this embodiment also uses a braking device of the kinetic energy recovery device 9 to lock the flapping wing body, forming a fixed-wing mode such as a forward-swept wing or a backward-swept wing with dihedral or anhedral angles, adapting to different environments and improving flight efficiency.

[0023] Figure 3 , Figure 4This invention illustrates a second embodiment of a flapping-wing aircraft, comprising a fuselage and a flapping-wing body with variable concave-convex wing surfaces. The flapping-wing body includes a front sparsity 1, a rear sparsity 2, wing ribs 12, and a skin. The front sparsity 1 and rear sparsity 2 form arc-shaped spars capable of forward and backward deflection along the wingspan direction, while the wing ribs 12 form arc-shaped wing ribs capable of vertical rotation along the upper arc of the airfoil. The front sparsity 1 and rear sparsity 2 are equipped with multiple worm gear transmission mechanisms, which are movably connected to the wing ribs 12 via universal couplings. Shock absorbers are provided on the upper and lower sides of the wing root ends of the front sparsity 1 and rear sparsity 2, forming suspensions 6, and the flapping-wing body is movably connected to the fuselage via hinges. The wing root ends of the front beam 1 and the rear beam 2 are combined to form a crossbeam, and two hydraulic motors are installed on the crossbeam to form a drive component 11. The drive motors drive the wing ribs 12 to deflect 90° in a cycle through gear meshing with the gears at the ends of the front beam 1 and the rear beam 2. At the same time, the worm gear transmission mechanism on the front beam 1 and the rear beam 2 speeds up the drive motors to deflect the wing ribs 12 in a cycle of 180°. This causes the upper convex and lower concave wing surface to change back and forth with the upper concave and lower convex wing surface, which causes the pressure on the upper and lower wing surfaces to be exchanged in a cycle, thereby driving the flapping wing body to flap. Combined with the reaction force of the wingtip sweepback, a lift thrust is generated, which realizes the flapping in a passive manner, greatly reducing the pressure on the wing surface and reducing the high requirements for the strength of the flapping wing structure and materials.

[0024] like Figure 4 As shown, the crossbeam formed by the wing root ends of the front beam 1 and the rear beam 2 is fixedly connected to the transmission rod 7. The tail of the transmission rod 7 has a bushing with a connecting shaft, which movably connects to the rocker arm of the crank-rocker mechanism 8, ensuring flexible transmission during flapping wing body movement. The tail end of the transmission rod 7 has a spring rod that movably connects to the guide rail 10 via rollers, allowing for automatic extension and retraction for stable connection. This controls the reciprocating motion of the flapping wing body in the vertical direction and, together with the suspension 6, movably connects the flapping wing body to the fuselage, forming a lever transmission mechanism to support the up-and-down flapping motion. The crank-rocker mechanism 8 is connected to a kinetic energy recovery device 9, consisting of a generator and a battery, via a clutch gearbox. This allows the flapping wing body to utilize the mechanical energy of its flapping motion against the airflow during updrafts and descents, driving the crank-rocker mechanism 8 via the transmission rod 7, which in turn drives the kinetic energy recovery device 9 to generate electricity and store energy, increasing range. The kinetic energy recovery device 9 also has a braking device to control the asynchronous flapping and sweeping motion of the flapping wing body, achieving flight attitude control of the flapping wing aircraft.

[0025] like Figure 3 , Figure 4As shown, the worm gear transmission mechanism movably connects the front beam 1 and the rear beam 2, and the exterior is provided with deformable material forming the leading and trailing edges of the flapping wing body, smoothly connecting the upper and lower skins to form a smooth wing surface. The wing rib 12 is fitted with rollers that pass between the upper and lower skins, and is flexibly connected to form a variable concave-convex wing surface. The skin is a flexible skin with a certain elasticity to enhance surface tension, and together with the universal coupling, it forms a balanced tension of the wing rib 12 to strengthen the flapping wing structure. This promotes the flapping wing body's downward flapping motion during the first half of the cycle when the drive component 11 controls the flapping wing body to have an upper concave and lower convex wing surface. The middle part of the flapping wing body sweeps forward to enhance the oncoming airflow and promote the downward flapping motion, while the tail sweeps backward to generate propulsion using reaction force. During the second half of the cycle when the drive component 11 controls the flapping wing body's wing surface to have an upper convex and lower concave wing surface, the middle part of the flapping wing body returns to center and arches upward, while the tail returns to center, lengthens the wingspan, and droops to reduce the upward airflow around the wingtips, further increasing the upward lift and generating the upward flapping motion.

[0026] like Figure 4 As shown, the flapping-wing aircraft of this embodiment of the invention mimics the characteristics of a bird's weighted wing, forming a concave-convex airfoil with a relatively wide chord. It achieves flapping motion by using a tail fin at the rear of the fuselage to control direction and altitude, and by using a thruster 16 to promote airflow and generate pressure on the wing surface. The flapping-wing aircraft of this embodiment also uses a braking device of the kinetic energy recovery device 9 to lock the flapping wing body into a fixed-wing mode, adapting to different environments and improving flight efficiency.

Claims

1. A passive flapping-wing device, comprising a fuselage and flapping wings movably connected to the fuselage, characterized in that, The airframe controls the flapping wing to reciprocate and deflect the pitch angle or cyclically change the upper and lower convex wing surfaces, promoting the exchange of pressure between the upper and lower wing surfaces in the face of the wind, thereby driving the flapping wing to flap and generate mechanical energy to form a flapping wing generator, or combining the reaction force of the sweeping swing to generate lift thrust to form a flapping wing aircraft. When the fuselage controls the flapping wing to reciprocate and deflect the pitch angle, the flapping wing is formed by the first wing section on the wing root side and the second wing section on the wing tip side being movably connected by the auxiliary rudder (4) to form a double convex wing or a symmetrical wing; the leading edge of the second wing tip is provided with a drive component (11) obliquely from the trailing edge of the wing root, which drives the second wing section to deflect the pitch angle and sweep angle to control the attitude, improve the lift of the first wing section, and generate propulsion by using the reaction force of the sweeping swing; When the fuselage controls the flapping wing to cyclically change the upper and lower convex wing surfaces, the flapping wing includes a front spar (1), a rear spar (2), wing ribs (12) and skin, and the front spar (1) and rear spar (2) form an arc-shaped wing spar that can deflect forward and backward along the wingspan direction, thereby forming the flapping wing with an arc-shaped structure, so that the wingtip can be swept back and swing in the deflection state to generate propulsion using reaction force.

2. The passive flapping wing device according to claim 1, characterized in that, The first wing section is provided with a front spar (1), a rear spar (2) and a middle spar (3), and the front end of the front spar (1) and the rear spar (2) are provided with a main rudder (5) which is movably connected to the fuselage, and the rear end is provided with a secondary rudder (4) which is movably connected to the second wing section; the front end of the middle spar (3) is provided with suspensions (6) on both the upper and lower sides which are movably connected to the fuselage, and the rear end is provided with a hinge which is movably connected to the second wing section; the main rudder (5) uses the suspensions (6) as a fulcrum to push and pull to drive the pitch angle of the first wing section to swing cyclically, and uses the pressure generated by the airflow on the upper and lower wing surfaces to drive the flapping wing to flap.

3. The passive flapping wing device according to claim 1 or 2, characterized in that, The front end of the central beam (3) is provided with a telescopic transmission rod (7), and the tail end of the transmission rod (7) is provided with a crank rocker mechanism (8) through a bushing. The tail end is provided with a guide rail (10), which, together with the main rudder (5) and the suspension (6), connects the flapping wing to the fuselage. The crank rocker mechanism (8) is connected to the kinetic energy recovery device (9) to form a flapping wing generator, which recovers the mechanical energy of the flapping wing driven by the wind to generate electricity.

4. The passive flapping wing device according to claim 1, characterized in that, The wing rib (12) forms an arc-shaped wing rib that can be flipped up and down along the upper arc direction; the front beam (1) and the rear beam (2) are provided with multiple worm gear transmission mechanisms, which are movably connected to the wing rib (12) through universal couplings and covered with the skin to form the flapping wing with changeable upper and lower convex wing surfaces; the front beam (1) and the rear beam (2) are provided with drive components (11) on the inner side of the wing root end, and suspensions (6) are provided on the upper and lower sides of the wing root end, which movably connect the flapping wing to the fuselage; the drive components (11) drive the front beam (1) and the rear beam (2) to swing back and forth synchronously, and drive the wing rib (12) to flip up and down through the worm gear transmission mechanism to realize the back and forth change of the upper and lower concave and convex wing surfaces, and promote the flapping wing to flap by using the pressure generated by the airflow to cycle and exchange on the upper and lower wing surfaces.

5. The passive flapping wing device according to claim 1 or 4, characterized in that, The front beam (1) and rear beam (2) are connected by a crossbeam and have a telescopic transmission rod (7) on the inner side of the front end. The transmission rod (7) has a crank rocker mechanism (8) at the tail end and a guide rail (10) at the tail end. The flapping wing is movably connected to the body by the suspension (6). The flapping wing generator is connected to the kinetic energy recovery device (9) through the crank rocker mechanism (8) to recover the mechanical energy of the flapping wing driven by the wind to generate electricity.

6. The passive flapping wing device according to claim 1 or 4, characterized in that, The worm gear transmission mechanism is provided with deformable material on the outside, which forms the front and rear edges of the flapping wing and smoothly connects to the skin; the wing rib (12) is fitted with rollers that pass between the skins of the upper and lower wing surfaces and are flexibly connected to form a variable convex wing surface; the skin is a flexible skin with a certain elasticity to enhance surface tension, and together with the universal coupling, it forms the balancing tension of the wing rib (12) to strengthen the overall structure of the flapping wing.

7. The passive flapping wing device according to claim 1, characterized in that, The kinetic energy recovery device (9) consists of a braking mechanism and an electrical energy recovery device. The aircraft is equipped with a tail fin and a thruster (16) to form a flapping-wing aircraft. It recovers the kinetic energy of the incoming airflow during updraft or descent to generate electricity and store energy to increase the flight range. The kinetic energy recovery device (9) can control the flapping wing to a fixed-wing mode through the braking mechanism to adapt to different flight environments and improve flight efficiency.

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