A flapping and flipping mechanism

Abstract

This invention discloses a flapping wing flipping mechanism, belonging to the field of micro-aircraft. This invention is used in flapping rotor aircraft. The flapping rotor aircraft includes a pivot sleeve, a fuselage frame, a servo motor drive unit, a turntable component, a crossbar, a flapping wing support component, a right flapping wing, a left flapping wing, a flapping wing flipping mechanism, a cable, and a flapping wing pivot component. The flapping wing flipping mechanism body uses the sudden changes in inertial and centrifugal forces during the transition between different motion modes of the flapping rotor aircraft as the main driving force to complete the flapping wing flipping. This invention uses the sudden changes in inertial and centrifugal forces during the transition between different motion modes of the flapping rotor aircraft as the main driving force to complete the flapping wing flipping, avoiding the reduction in mechanical efficiency caused by installing a servo motor at the flapping end of the flapping wing mechanism. This invention achieves the conversion between different flapping modes of the flapping wing through flapping wing flipping, enabling the flapping rotor aircraft to achieve optimal torsion angle amplitude in different motion modes, thereby improving the flight efficiency of the flapping rotor aircraft.

Description

Technical Field

[0001] The present invention discloses a flapping wing flipping mechanism, which belongs to the field of micro-miniature aircraft. Background Technology

[0002] Since its inception in the 1990s, the concept of micro-aircraft has attracted much attention from scholars. Compared to fixed-wing and rotary-wing micro-aircraft, flapping-wing micro-aircraft possess greater aerodynamic lift and maneuverability. While bird-inspired flapping wings offer high forward flight performance and aerodynamic efficiency, they lack vertical takeoff and landing (VTOL) and hovering capabilities. Hummingbird-inspired flapping wings can achieve VTOL and hovering, but their hovering and forward flight efficiency is relatively low. To improve the aerodynamic lift and efficiency of flapping-wing micro-aircraft, the inventors proposed a flapping rotor concept in 2009, combining flapping wing flapping with an autorotator. This involves mounting a pair of axisymmetric flapping wings on the longitudinal axis of the aircraft. When the flapping wings, driven by an electric motor, move up and down at a certain flapping frequency and angle, they generate lift and thrust. The thrust acting on the axisymmetrically mounted flapping wings creates a pair of torques around the axis, enabling the flapping wings to spin. Since no torque is applied through the longitudinal axis, flapping rotor aircraft do not need to add counter-torque like helicopter tail rotors. Therefore, flapping rotors are not only simpler in structure than rotorcraft, but also have a higher aerodynamic lift coefficient. Compared with flapping rotor aircraft, the aerodynamic lift coefficient and efficiency are greatly improved.

[0003] While flapping rotor micro-aircraft have significant advantages, their flight mode, similar to that of helicopters, remains a rotorcraft mode, limiting their forward flight efficiency, speed, and range. If the ability to switch between flapping and bird-wing-inspired flapping and gliding modes could be achieved, flapping rotor aircraft could achieve optimal flight efficiency and speed in multiple modes, meeting diverse flight performance and mission requirements, and thus possessing greater application scope and potential. Summary of the Invention

[0004] The purpose of this invention is to provide a flapping wing flipping mechanism that uses the abrupt changes in inertial and centrifugal forces during the transition between different flapping modes as the main driving force to complete the flapping wing flipping, avoiding the reduction in mechanical efficiency caused by installing a servo motor in the flapping mechanism to drive the flapping wing flipping. This invention achieves the switching between different flapping modes of the flapping wing through flapping wing flipping, thereby improving the flight efficiency of flapping rotor aircraft.

[0005] This invention is achieved through the following technical solution:

[0006] The flapping rotor aircraft includes a pivot sleeve, a fuselage frame, a servo motor drive unit, a turntable component, a crossbar, a flapping wing support component, a right flapping wing, a left flapping wing, a flapping wing flipping mechanism, a cable, and a flapping wing pivot component. The flapping wing flipping mechanism includes a passive torsion limit tube, a threaded sleeve, a spring, a flapping wing tie rod, and a cable.

[0007] The fuselage frame is the upper crossbeam of the aircraft fuselage, and the servo motor drive unit is fixed to the fuselage frame. The servo motor drive unit includes a servo motor and an elastic anti-rotation plate. The elastic anti-rotation plate is vertically fixed to the drive shaft of the servo motor and can rotate within a range of 0° to 90° under the drive of the servo motor, where 0° corresponds to the horizontal state and 90° corresponds to the vertical state.

[0008] The rotating shaft sleeve is fixed longitudinally to the fuselage frame, and the flapping wing shaft inserted into the rotating shaft sleeve can slide up and down and rotate. The flapping wing shaft component includes a longitudinally mounted shaft and a top bearing. The top bearing is used to connect the flapping wing shaft to the brackets of the left and right flapping wings.

[0009] The left and right flapping wings are defined based on the orientation of the flapping rotor aircraft in its initial placement state.

[0010] The flapping wing support component includes a flapping wing support and a support bearing. The top of the flapping wing support is hinged to the flapping wing beams on both sides, and the lower end of the support is hinged to the bearing and then fitted onto the outside of the rotating shaft sleeve. The top of the flapping wing support, together with the flapping wing, the flipping mechanism, and the rotating shaft, forms a whole that rotates around the rotating shaft sleeve while repeatedly moving up and down, forming a flapping motion. The bearing at the lower end of the flapping wing support is fixed to a crossbar in the outer horizontal plane.

[0011] The turntable component includes a turntable, a turntable crossbar, and a turntable bearing. The turntable is mounted on the outside of the shaft sleeve via the turntable bearing, and the turntable is connected to the lower end of the flapping wing support via a pull cable, allowing it to rotate freely around the shaft sleeve with the flapping wing support. The turntable crossbar is fixedly connected to the turntable.

[0012] The flapping wing flipping mechanism consists of five main components, including a screw groove sleeve, a passive torsion limiting tube, a flapping wing tie rod, a spring, and a pull wire.

[0013] The outer wall of the spiral groove sleeve is engraved with a pair of helical grooves that wrap around half a circumference of the tube. The curve of the helical grooves on the outer wall of the spiral groove sleeve is determined according to the ratio of the outer diameter of the tube to the axial movement. A pair of radial spring pins are installed at both ends of the grooves, namely a near-beam spring pin and a far-beam spring pin. The inner end of the spiral groove sleeve is hinged to the upper end of the flapping wing support and the top bearing.

[0014] The inner diameter of the passive torsion limiting tube is the same as the outer diameter of the threaded sleeve. A thin circular ring is fixed to the outer side of the passive torsion limiting tube. The outer diameter of the ring is the same as the outer diameter of the passive torsion limiting tube, and the inner diameter is the same as the outer diameter of the threaded sleeve. A pair of limiting rods, designated as torsion limiting rod number one and torsion limiting rod number two, are fixedly extended from the outer side of the ring. The inner wall of the passive torsion limiting tube is provided with a protruding slider.

[0015] The slider protruding from the inner wall of the passive torsion limiting tube is aligned with the spiral groove on the outer wall of the screw groove sleeve, so that when the flapping wing flips, it drives the passive torsion limiting tube to be pulled out and rebound along the axial direction of the flapping wing tie rod, while rotating around the screw groove sleeve. The rotation angle is set in the range of 140-160° according to the needs of different motion mode switching.

[0016] The flapping wing tie rod is installed inside the threaded sleeve. The outer end of the flapping wing tie rod is connected to the root end of the main beam of the left flapping wing, and the inner end of the flapping wing tie rod is connected to the upper end of the tie line. The middle part of the flapping wing tie rod has a thickened section with a length less than 50% of the distance between the near beam spring pin and the far beam spring pin. The diameter of the thickened section is close to the inner diameter of the threaded sleeve, and the two ends of the thickened section have a 45° bevel angle. There is a convex plate at each of the inner and outer ends of the flapping wing tie rod. The outer diameter of the inner convex plate is close to the inner diameter of the threaded sleeve, and the outer diameter of the outer convex plate is close to the outer diameter of the threaded sleeve. The flapping wing tie rod can slide and rotate freely inside the threaded sleeve.

[0017] The pull wire passes around the root hinge hole at the root end of the screw groove sleeve and connects its lower end to the turntable crossbar for connecting the turntable and the flapping wing pull rod.

[0018] The spring is connected at both ends to the inner ends of the passive torsion limiting tube and the screw groove sleeve, respectively. The spring is in a stretched state during flapping rotor motion mode and in its original state during flapping rotor motion mode. The abrupt changes in inertial and centrifugal forces generated by the flapping rotor during the transition between different motion modes serve as the primary driving force for flapping rotor rotation.

[0019] Preferably, both the elastic anti-rotation plate and the spring are made of steel with a low elastic modulus.

[0020] To ensure that the flapping wing has a high stiffness-to-weight ratio, it is preferable that the wing spars are made of carbon fiber composite material and the wing membrane is preferably polyimide.

[0021] Preferably, both the passive torsion limiting tube and the threaded sleeve are made of 7000 series aluminum alloy material.

[0022] Preferably, the flapping wing tie rod is made of aluminum alloy or carbon fiber composite material, and a thin layer of brass is electroplated on the outer surface of the protruding section of the flapping wing tie rod, which serves as a lubricant.

[0023] Preferably, the design of the spiral grooves on the outer wall of the spiral sleeve, which are arranged around half the circumference of the tube, should be within a variation range of ±0.2 based on the ratio of the outer diameter of the sleeve to the stroke of 0.625, in order to meet the requirements of the flapping wing flipping device to be suitable for flight devices of different sizes.

[0024] To ensure sufficient lift for the flapping rotorcraft, it is preferable that the twist angle during flapping is between -10° and 45°. Here, -10° corresponds to the maximum twist angle during downward flapping, and 45° corresponds to the maximum twist angle during upward flapping.

[0025] The working method of the flapping wing flipping mechanism disclosed in this invention is as follows:

[0026] In flapping rotor flight mode, the flapping wings mounted on both sides of the fuselage are in an anti-symmetrical installation position. The two flapping wings include a left flapping wing and a right flapping wing. At the start of movement, the elastic anti-rotation plate on the servo motor drive shaft is in a horizontal position, not hindering the normal flapping and rotational motion of the flapping rotor aircraft. When the flapping wing shaft moves longitudinally up and down within the shaft sleeve under the drive of the motor, the roots of the two flapping wings move periodically up and down with the flapping wing shaft, causing the wing surfaces to flap. Simultaneously, this drives the two flapping wings and the flapping wing support components to rotate around the flapping wing shaft and the shaft sleeve, forming a flapping motion. Under the influence of the inertial and centrifugal forces of the flapping rotor, the flapping rotor tie rod connected to the main beam is pulled out of the threaded sleeve. This pull rod then pushes out the passive torsion limiting tube via the outer end cam. As the passive torsion limiting tube is pushed out, it rotates along the groove on the surface of the threaded sleeve. The spring connected to the passive torsion limiting tube is in a stretched state. The flapping rotor tie rod is pulled out until the thickened section lifts the near-beam spring pin at the outer end of the threaded sleeve, while the far-beam spring pin remains unlifted. This, in turn, blocks the cam at the inner end of the flapping rotor tie rod, limiting the length of the pull-out tie rod. At this point, the first and second torsion limiting rods are at the upper and lower limits of the torsion angle in the optimal flapping mode of the flapping rotor, corresponding to +45° and -10° respectively.

[0027] When switching from flapping rotor flight mode to flapping rotor mode, the motor driving the flapping rotor is shut down. At the same time, a command is issued to rotate the elastic anti-rotation plate on the servo motor drive shaft 90° to a vertical position to stop the turntable component from rotating. The flapping rotor, along with the flapping rotor support component and crossbar, pushes away the elastic anti-rotation plate under the action of rotational inertia and continues to rotate. This drives the cable connected to the inner end of the flapping rotor beam to rotate. Since the lower end of the cable is connected to the turntable crossbar of the turntable component that is being stopped from rotating, the distance between the upper and lower ends of the cable increases and it is tightened. This pulls the flapping rotor beam to slide inward, causing the near beam spring pin on the screw groove sleeve to spring back to its original position and release the pin connection to the passive torsion limit tube. The passive torsion limit tube, which is no longer constrained by the pin, is also moved inward with the flapping rotor rod under the pull of the spring. At the same time, it rotates along the groove on the outer surface of the screw groove sleeve, causing the first torsion limit rod to push the rib at the root of the left flapping rotor to the upper and lower limit positions of the torsion angle of the optimal flapping rotor mode, corresponding to the range of +45° and -10°, respectively. At this point, the flapping wing lever slides inward to its limit, lifting the far beam spring pin at the inner end of the screw groove sleeve, locking the passive torsion limit tube and torsion limit rod in the flapping wing flapping mode. The spring is now in its original state. The flapping wing, flapping wing support assembly, and the crossbar at the lower end of the support continue to rotate one revolution under the influence of rotational inertia, causing the cable connecting the turntable assembly and the flapping wing lever to tighten, thus pulling the flapping wing lever inward to complete the flapping wing flipping process. At this point, the kinetic energy of the flapping rotor has been largely used to drive the flapping wing flipping, and the rotational inertia and speed are significantly reduced. When the crossbar at the lower end of the flapping wing support assembly rotates again to the position of the elastic anti-rotation plate, it is blocked and remains in an anti-rotation state. After flipping, the flapping wing flipping device is in the spring's original state, and the leading edges of the flapping wings on both sides of the aircraft are aligned with the forward flight direction, forming a symmetrical arrangement. If the drive motor remains off, the flapping rotor aircraft will enter a fixed-wing gliding flight mode; if the drive motor is turned on, the flapping rotor aircraft will enter a flapping wing flight mode.

[0028] During the reverse transition from flapping-wing flight mode to flapping-rotor mode, a command is first issued to rotate the elastic anti-rotation plate on the servo motor component to the 0° horizontal position, releasing the rotational freedom of the turntable component and the crossbar. At this time, the cable is relaxed, releasing the constraint on the outward sliding of the flapping-wing lever. The inertial force generated by the flapping of the right and left flapping wings pulls the flapping-wing lever outward, and pushes the passive torsion limit tube outward and rotates through the outer end cam. As the flapping and rotation of the flapping wings accelerate, the generated inertial force and centrifugal force eventually pull the flapping-wing lever and the passive torsion limit tube completely out and lock them through the near beam spring pin at the outer end. At this time, the torsion limit rod also rotates with the passive torsion limit tube to the upper and lower limit positions of the torsion angle of the flapping rotor, completing the reverse transition from flapping-wing to flapping-rotor mode, and the flapping-rotor aircraft enters the flapping-rotor flight mode.

[0029] Beneficial effects:

[0030] 1. The flapping wing flipping device disclosed in this invention utilizes the changes in inertial force and centrifugal force generated by the flapping wing in different flight modes of a flapping rotor aircraft as the main driving force source to complete the up and down flipping of the flapping wing, which has the advantage of higher mechanical efficiency.

[0031] 2. The flapping wing flipping device disclosed in this invention, based on achieving the beneficial effect 1, can achieve the optimal twist angle amplitude of flapping rotor aircraft in different flight modes according to the design requirements of the twisting motion of flapping rotor and flapping wing.

[0032] 3. The flapping wing flipping device disclosed in this invention, based on achieving the beneficial effects 1 and 2, can realize the up-and-down flipping of the flapping wings on both sides or one side of the bionic micro-aircraft, thereby realizing the conversion of multiple flight modes such as flapping rotor, flapping wing, and fixed wing during flight. Compared with the single flapping rotor, flapping wing, and fixed wing flight modes of current bionic aircraft, it combines the high-efficiency vertical take-off and landing and hovering performance of flapping rotor mode with the high-efficiency acceleration forward flight and cruise performance of flapping wing and fixed wing flight modes. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the flapping wing flipping mechanism of the present invention installed on a flapping rotor aircraft in flapping rotor mode.

[0034] Figure 2 This is a schematic diagram of the flapping wing flipping mechanism of the present invention installed in a flapping rotor aircraft in flapping wing mode.

[0035] Figure 3 This is a schematic diagram of the assembly and components of the flapping wing flipping mechanism body of the present invention.

[0036] Figure 4 This is a schematic diagram of the flapping wing flipping mechanism body of the present invention in flapping rotor motion mode.

[0037] Figure 5 This is a schematic diagram of the flapping wing flipping mechanism body of the present invention in flapping wing motion mode.

[0038] Figure 6 This is a cross-sectional schematic diagram of the flapping wing tilting mechanism body of the present invention in flapping rotor motion mode.

[0039] Figure 7 This is a cross-sectional schematic diagram of the flapping wing flipping mechanism body of the present invention in flapping wing motion mode.

[0040] Figure 8 This is a front view of the passive torsion limiting tube of the flapping wing flipping mechanism body of the present invention in flapping rotor motion mode.

[0041] Figure 9This is a front view of the passive torsion limiting tube of the flapping wing flipping mechanism body of the present invention in flapping wing motion mode.

[0042] Among them: 1-rotating shaft sleeve, 2-fuselage frame, 3-servo motor drive component, 4-turntable component, 5-crossbar, 6-flapping wing bracket component, 7-right flapping wing, 8-left flapping wing, 9-flapping wing flipping mechanism, 10-pull cable, 11-flapping wing rotating shaft component; 9.1.1-passive torsion limit tube, 9.1.2-screw groove sleeve, 9.1.3-spring, 9.1.4-flapping wing tie rod, 9.1.5-hinge hole, 9.1.1.1-first torsion limit rod, 9.1.1.2-second torsion limit rod, 9.1.2.1-near beam spring pin, 9.1.2.2-far beam spring pin. Detailed Implementation

[0043] To better implement this invention and clarify its key points, the invention will be described in detail below with reference to the accompanying drawings.

[0044] like Figure 1 As shown, this embodiment discloses a flapping wing flipping mechanism for a micro-sized flapping rotor aircraft with multiple flight mode switching functions. The components associated with the flapping wing flipping mechanism mounted on the flapping rotor aircraft include a pivot sleeve 1, a fuselage frame 2, a servo motor drive unit 3, a turntable component 4, a crossbar 5, a flapping wing support component 6, a right flapping wing 7, a left flapping wing 8, a flapping wing flipping mechanism 9, a cable 10, and a flapping wing pivot 11.

[0045] The fuselage frame 2 is the upper crossbeam of the aircraft fuselage. The rotating shaft sleeve 1 is fixed longitudinally on the fuselage frame 2. The flapping wing shaft 11.1 is inserted into the rotating shaft sleeve 1 and can slide up and down and rotate. The servo motor drive 3 is fixed on the fuselage frame 2.

[0046] The servo motor drive unit 3 includes a servo motor 3.1 and an elastic anti-rotation plate 3.2. An elastic anti-rotation plate 3.2 is fixed on the drive shaft of the servo motor 3.1, and can rotate within the range of 0° to 90° under the drive of the servo motor 3.1, where 0° corresponds to the horizontal state and 90° corresponds to the vertical state.

[0047] The turntable component 4 includes a turntable 4.1, a turntable crossbar 4.2, and a turntable bearing 4.3. The turntable 4.1 is mounted on the outside of the rotating shaft sleeve 1 via the turntable bearing 4.3, and can rotate freely around the rotating shaft sleeve 1.

[0048] The flapping wing support component 6 includes a flapping wing support 6.1 and a support bearing 6.2. The lower end of the flapping wing support 6.1 is hinged to the support bearing 6.2 and fitted onto the outside of the rotating shaft sleeve 1. The upper end of the flapping wing support 6.1 is connected to the flapping rotor and rotates around the rotating shaft sleeve 1 following the movement of the flapping rotor. The support bearing 6.2 is fixed to the crossbar 5 in the outer horizontal plane and is connected to the turntable 4.1 installed below through three connecting lines, so that the turntable 4.1 can be pulled to follow the flapping wing support 6.1 to rotate around the rotating shaft sleeve 1.

[0049] The right flapping wing 7 and the left flapping wing 8 are defined according to the orientation of the flapping rotor aircraft in its initial placement state. The spars of both the right flapping wing 7 and the left flapping wing 8 are made of carbon fiber, and the wing membranes are made of polyimide to ensure that the flapping wings have a certain rigidity while maintaining a lightweight design.

[0050] This embodiment discloses a flapping wing flipping mechanism, such as... Figure 3 As shown, it consists of five main components, including a passive torsion limiting tube 9.1.1, a threaded sleeve 9.1.2, a spring 9.1.3, a flapping wing tie rod 9.1.4, and a hinge hole 9.1.5.

[0051] The passive torsion limiting tube 9.1.1 is made of 7000 series aluminum alloy material. A pair of limiting rods are fixedly extended from its outer side, which are respectively designated as torsion limiting rod No. 1 9.1.1.1 and torsion limiting rod No. 2 9.1.1.2. The inner wall is provided with a protruding slider 9.1.1.3. The slider 9.1.1.3 is aligned with the spiral groove on the outer wall of the threaded sleeve 9.1.2, so that the passive torsion limiting tube 9.1.1, which is sleeved on the outside of the threaded sleeve 9.1.2, can rotate when sliding axially.

[0052] The grooved sleeve 9.1.2 is made of 7000 series aluminum alloy, and its outer wall is engraved with a pair of spiral grooves that wrap around half of the tube's circumference. The curve of the spiral grooves is determined according to the ratio of the tube's outer diameter to its axial movement. A pair of radial spring pins are installed at both ends of the grooves, namely the near-beam spring pin 9.1.2.1 and the far-beam spring pin 9.1.2.2. The inner end of the grooved sleeve 9.1.2 is hinged to the flapping wing bracket 6.1 and the top bearing 11.2 via a hinged rod and a hinge hole 9.1.5.

[0053] The spring 9.1.3 is made of low-modulus steel, and its two ends are respectively connected to the inner end of the passive torsion limiting tube 9.1.1 and the inner end of the threaded sleeve 9.1.2. The spring 9.1.3 is in a stretched state when the passive torsion limiting tube 9.1.1 is pulled out in flapping rotor motion mode, and in the original state in flapping rotor motion mode.

[0054] The flapping-wing tie rod 9.1.4 is made of carbon fiber composite material, with a thickened section in its middle that is less than 50% the length of the distance between the near-beam spring pin 9.1.2.1 and the far-beam spring pin 9.1.2.2, and the diameter of the thickened section is close to the inner diameter of the threaded sleeve 9.1.2. Each end of the flapping-wing tie rod 9.1.4 has a convex disc; the outer diameter of the outer convex disc is close to the outer diameter of the threaded sleeve 9.1.2, and the outer diameter of the inner convex disc is close to the inner diameter of the threaded sleeve 9.1.2. The flapping-wing tie rod 9.1.4 is installed inside the threaded sleeve 9.1.2. The outer surface of the protruding section of the flapping-wing tie rod 9.1.4 is electroplated with a thin layer of brass, and its thickened section is located between the near-beam spring pin 9.1.2.1 and the far-beam spring pin 9.1.2.2, allowing for free sliding and rotation within the threaded sleeve 9.1.2. The outer end of the flapping wing tie rod 9.1.4 is fixed to the left flapping wing 8, and the inner end is connected to the pull wire 10.

[0055] The pull wire 10 passes around the hinge point of the hinge hole 9.1.5 and connects its lower end to the turntable crossbar 4.2 of the turntable component 4, for connecting the turntable 4 and the flapping wing pull rod 9.1.4.

[0056] The outer end of the flapping wing tie rod 9.1.4 of the flapping wing flipping mechanism is connected to the root end of the main beam of the left flapping wing 8. The inner end of the screw groove sleeve 9.1.2 is hinged to the upper end of the flapping wing bracket 6.1 through the support rod, and the root is hinged to the top bearing 11.2 of the flapping wing shaft 11.1 through the hinge hole 9.1.5.

[0057] The working method of the flapping wing flipping mechanism disclosed in this invention is as follows:

[0058] In flapping rotor flight mode, the flapping wings mounted on both sides of the fuselage are in a position similar to... Figure 1 The anti-symmetrical installation position is shown. The two flapping wings include a right flapping wing 7 and a left flapping wing 8. At the start of movement, the elastic anti-rotation plate 3.2 on the drive shaft of the servo motor 3.1 is in a horizontal position, which does not hinder the normal flapping and rotational movement of the flapping rotor aircraft. When the flapping wing shaft component 11 moves up and down longitudinally within the shaft sleeve 1 under the drive of the motor, the roots of the two flapping wings move up and down periodically with the flapping wing shaft 11.1, causing the wing surface to flap, and at the same time driving the two flapping wings and the flapping wing support component 6 to rotate around the flapping wing shaft 11.1 and the shaft sleeve 1, forming a flapping motion. Figure 4 As shown, under the action of inertial force and centrifugal force, the flapping rotor pulls out the flapping rotor rod 9.1.4 along with the passive torsion limiting tube 9.1.1. When the passive torsion limiting tube 9.1.1 is pulled out, it rotates 150 degrees along the groove on the surface of the threaded sleeve 9.1.2. The spring 9.1.3 connected to the passive torsion limiting tube 9.1.1 is in a stretched state. The flapping rotor rod 9.1.4 is pulled outward until the thickened section pushes up the near-beam spring pin 9.1.2.1 at the outer end of the threaded sleeve 9.1.2, locking the passive torsion limiting tube 9.1.1 in place. Figure 6The positions shown are as indicated. Torsional limit rod 9.1.1.1 and torsion limit rod 9.1.1.2 are respectively positioned as shown. Figure 8 The upper and lower limits of the twist angle for the optimal flapping mode of the rotor shown correspond to +45 degrees and -10 degrees, respectively.

[0059] When transitioning from flapping rotor flight mode to flapping rotor mode, the motor driving the flapping rotor is shut down, and a command is issued to rotate the elastic anti-rotation plate 3.2 on the drive shaft of servo motor 3.1 by 90 degrees. Figure 2 The vertical position shown prevents the turntable component 4 from rotating, while the flapping rotor, along with the flapping rotor support component 6 and the crossbar 5, continues to rotate under the action of rotational inertia, pushing aside the elastic anti-rotation plate 3.2. This drives the pull wire 10 connected to the inner end of the flapping rotor pull rod 9.1.4 to rotate. Since the lower end of the pull wire 10 is connected to the turntable crossbar 4.2 of the anti-rotation turntable component 4, the distance between the upper and lower ends of the pull wire 10 increases, causing it to tighten and thus pulling the flapping rotor pull rod 9.1.4 to slide inward. The near-beam spring pin 9.1.2.1 on the threaded sleeve 9.1.2 moves inward under the action of the spring 9.1.3, releasing the pin connection to the passive torsion limit tube 9.1.1. The passive torsion limit tube 9.1.1, no longer constrained by the pin, also slides inward with the flapping rotor pull rod 9.1.4 under the tension of the spring 9.1.3, while simultaneously rotating along the spiral groove. Figure 5 As shown. Simultaneously, the first torsion limit lever 9.1.1.1 pushes the wing rib at the root of the left flapping wing 8 to flip as shown. Figure 9 The location shown. (As indicated) Figure 7 As shown, the flapping wing lever 9.1.4 slides inward to its limit, lifting the far beam spring pin 9.1.2.2 at the inner end of the screw groove sleeve 9.1.2, locking the passive torsion limit tube 9.1.1. At this time, the spring 9.1.3 returns to its unstretched state. The flapping rotor, flapping wing support component 6, and the crossbar 5 at the lower end of the support continue to rotate under the action of rotational inertia, causing the pull wire 10 connected to the turntable component 4 to be tightened, thereby pulling the flapping wing lever 9.1.4 to slide inward to complete the above-mentioned flapping wing flipping process. At this time, the kinetic energy of the flapping rotor has been basically used to drive the flapping wing flipping, and the rotational inertia and rotational speed are greatly reduced. When the crossbar 5 at the lower end of the flapping wing support component 6 rotates one revolution and hits the elastic anti-rotation plate 3.2 again, it is blocked and stops in the anti-rotation state. After flipping, the flapping wing flipping device is in the original state of spring 9.1.3, and the leading edges of the flapping wings on both sides of the flapping rotor aircraft are aligned with the forward flight direction, forming a symmetrical arrangement. At this time, if the drive motor is kept off, the flapping rotor aircraft will enter the fixed-wing gliding flight mode; if the drive motor is turned on, the flapping rotor aircraft will enter the flapping flight mode.

[0060] During the reverse transition from flapping-wing flight mode to flapping-rotor mode, a command is first issued to rotate the elastic anti-rotation plate 3.2 on the servo motor component 3 to the 0° horizontal position, releasing the rotational freedom of the turntable component 4 and the crossbar 5. At this time, the pull cable 10 is released, eliminating the constraint on the outward sliding of the flapping-wing pull rod 9.1.4. Under the action of the inertial force and centrifugal force generated by the flapping of the right flapping wing 7 and the left flapping wing 8, the flapping-wing pull rod 9.1.4 is pulled and the passive torsion limit tube 9.1.1 is pushed outward to slide and rotate, driving the left flapping wing 8 to flip and enter the flapping-rotor mode. As the flapping frequency and speed increase, the flapping-wing pull rod 9.1.4 and the passive torsion limit tube 9.1.1 are finally fully pulled out and locked in the flapping-rotor mode, completing the reverse transition from flapping-wing to flapping-rotor mode, and the flapping-rotor aircraft enters the flapping-rotor flight mode.

[0061] The above detailed description further illustrates the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flapping wing flipping mechanism for a flapping rotor aircraft, characterized in that: The flapping rotor aircraft includes a pivot sleeve (1), a fuselage frame (2), a servo motor drive unit (3), a turntable component (4), a crossbar (5), a flapping wing support component (6), a right flapping wing (7), a left flapping wing (8), a flapping wing flipping mechanism (9), a cable (10), and a flapping wing pivot component (11). The fuselage frame (2) is the upper crossbeam of the aircraft fuselage. The rotating shaft sleeve (1) is fixed longitudinally on the fuselage frame (2). The flapping wing rotating shaft (11.1) is inserted into the rotating shaft sleeve (1) to realize up and down sliding and rotation. The servo motor drive (3) is fixed on the fuselage frame (2). The servo motor drive unit (3) includes a servo motor and an elastic anti-rotation plate; an elastic anti-rotation plate is fixed on the drive shaft of the servo motor, which can rotate within the range of 0° to 90° under the drive of the servo motor, where 0° corresponds to the horizontal state and 90° corresponds to the vertical state. The turntable component (4) includes a turntable, a turntable crossbar and a turntable bearing; the turntable is mounted on the outside of the rotating shaft sleeve (1) through the turntable bearing, and the turntable and the turntable bearing can rotate freely around the rotating shaft sleeve (1) under the action of centrifugal force generated when the flapping rotor aircraft moves. The flapping wing support component (6) includes a flapping wing support and a support bearing; the lower end of the flapping wing support is hinged to the support bearing (6.2) and then fitted onto the outside of the rotating shaft sleeve (1). The flapping wing support and the support bearing can rotate around the rotating shaft sleeve (1) under the action of centrifugal force when the fuselage moves; the support bearing is fixedly connected to the crossbar (5) in the outer horizontal plane. The right flapping wing (7) and the left flapping wing (8) are defined according to the orientation of the flapping rotor aircraft in its initial placement state; The flapping wing flipping mechanism (9) consists of a flapping wing flipping mechanism body (9.1), a servo motor drive (3), a turntable component (4), a crossbar (5), and a pull wire (10); the front part of the flapping wing flipping mechanism (9) is connected to the main beam of the left flapping wing (8), the middle part is hinged to the upper end of the flapping wing bracket, and the root is fitted onto the upper end of the flapping wing rotating shaft after being hinged to the top bearing; The flapping wing pivot component (11) includes a flapping wing pivot and a top bearing; the top bearing is used to connect the flapping wing pivot to the flapping wing support. The flapping wing flipping mechanism body (9.1) is used as the main driving force source to complete the flapping wing flipping when the flapping rotor aircraft undergoes sudden changes in inertial force and centrifugal force during different motion mode transitions. The flapping wing flipping mechanism body (9.1) includes a passive torsion limiting tube (9.1.1), a threaded sleeve (9.1.2), a spring (9.1.3), a flapping wing tie rod (9.1.4), and a positioning hole (9.1.5). A pair of limiting rods are fixedly extended from the outside of the passive torsion limiting tube (9.1.1), and are respectively designated as torsion limiting rod No. 1 ( 9.1.1.1) and No. 2 torsion limit rod ( 9.1.1.2), with a protruding slider (9.1.1.3) on the inner wall; the slider (9.1.1.3) is aligned with the spiral groove on the outer wall of the spiral sleeve (9.1.2) to realize the axial advancement or axial rebound of the passive torsion limit tube (9.1.1) when the flapping wing reversal mechanism body (9.1) is in operation; The outer wall of the threaded sleeve (9.1.2) is engraved with a pair of spiral grooves that wrap around half a circumference of the tube. A pair of radial spring pins are installed at both ends of the grooves, namely, near-beam spring pins ( 9.1.2.1) and far beam spring pin (9.1.2.2); the inner end of the spiral groove sleeve (9.1.2) is hinged to the top bearing at the upper end of the flapping wing bracket and flapping wing pivot component (11); the curve of a pair of spiral grooves around half a circumference of the outer wall of the spiral groove sleeve (9.1.2) is determined according to the ratio of the outer diameter of the tube to the axial movement; The spring (9.1.3) is connected at both ends to the inner end of the passive torsion limiting tube (9.1.1) and the inner end of the threaded sleeve (9.1.2); the spring (9.1.3) is in a semi-extended state in the flapping rotor motion mode and in a compressed state in the flapping rotor motion mode; the spring (9.1.3) is compressed as the threaded sleeve (9.1.2) is advanced; The flapping wing tie rod (9.1.4) has a section in the middle that is shorter than the near beam spring pin ( A thickened section, 50% of the distance between the far beam spring pin (9.1.2.1) and the far beam spring pin (9.1.2.2), with the diameter of the thickened section matching the inner diameter of the threaded sleeve (9.1.2); each end of the flapping rod (9.1.4) has a convex disc with an outer diameter close to the inner diameter of the threaded sleeve (9.1.2); the flapping rod (9.1.4) is installed inside the threaded sleeve (9.1.2), and the thickened section is located near the far beam spring pin (9.1.2.1). Between 9.1.2.1) and the far beam spring pin (9.1.2.2), free rotation and sliding are achieved in the screw groove sleeve (9.1.2); the outer end of the flapping wing tie rod (9.1.4) is fixed to the left flapping wing (8), and the inner end is connected to the pull wire (10). The pull wire (10) passes through the positioning hole (9.1.5) and connects its lower end to the turntable crossbar of the turntable component (4) for connecting the turntable component (4) and the flapping wing pull rod (9.1.4).

2. The flapping wing flipping mechanism as described in claim 1, characterized in that: Both the elastic anti-rotation plate and the spring (9.1.3) are made of aluminum alloy.

3. The flapping wing tilting mechanism as described in claim 1, characterized in that: The flapping wing spars are made of carbon fiber or glass fiber composite materials, and the wing membrane is preferably polyimide.

4. The flapping wing tilting mechanism as described in claim 1, characterized in that: The passive torsion limiting tube (9.1.1) and the threaded sleeve (9.1.2) are both made of 7000 series aluminum alloy material.

5. The flapping wing flipping mechanism as described in claim 1, characterized in that: The flapping wing tie rod (9.1.4) is made of carbon fiber composite material, and a layer of brass is electroplated on the outer surface of the protruding section of the flapping wing tie rod (9.1.4).

6. The flapping wing tilting mechanism as described in claim 1, characterized in that: The design of the spiral grooves on the outer wall of the spiral sleeve (9.1.2) with a pair of spiral grooves around half a circumference of the tube should be within a range of ±0.2 based on the ratio of the outer diameter of the sleeve to the stroke of 0.625, so as to meet the requirements of the flapping wing flipping device to be suitable for flight devices of different sizes.

7. The flapping wing flipping mechanism as described in claim 1, characterized in that: The twist angle range during the flapping motion is between -10 degrees and -45 degrees; where -10 degrees corresponds to the maximum downward twist angle and 45 degrees corresponds to the maximum upward twist angle.

8. A flapping wing flipping mechanism as described in claim 1, 2, 3, 4, 5, 6, or 7, characterized in that: In flapping rotor flight mode, the flapping wings installed on both sides of the fuselage are in an anti-symmetrical installation position; the flapping wings on both sides include the right flapping wing (7) and the left flapping wing (8); when the movement begins, the elastic anti-rotation plate on the servo motor drive shaft is in a horizontal position, which does not hinder the normal flapping and rotational movement of the flapping rotor aircraft; when the flapping wing pivot component (11) moves up and down longitudinally in the pivot sleeve (1) under the drive of the motor, the roots of the two flapping wings move up and down periodically with the flapping wing pivot (11.1) to make the wing surface flap, and at the same time drive the two flapping wings and the flapping wing support component (6) to rotate around the flapping wing pivot and the pivot sleeve (1), forming flapping motion; under the action of inertial force and centrifugal force, the flapping rotor pulls out the flapping wing tie rod (9.1.4) along with the passive torsion limit tube (9.1.1), and when the passive torsion limit tube (9.1.1) is pulled out, it rotates 150 degrees along the groove on the surface of the threaded sleeve (9.1.2), connecting the passive torsion limit tube (9.1.1). 9.1.1) The spring (9.1.3) is in a semi-stretched state, and the flapping wing tie rod (9.1.4) is pulled outward until the thickened section closes the near-beam spring pin at the outer end of the threaded sleeve (9.1.2). 9.1.2.1) is lifted, and the far beam spring pin (9.1.2.2), not being lifted, locks the cam of the flapper beam shaft (9.1.4), thus locking the passive torsion limit tube (9.1.1); the first torsion limit rod ( 9.1.1.1) and No. 2 torsion limit rod ( 9.1.1.2) are respectively located at the upper and lower limits of the twist angle of the optimal flapping mode of the flapping rotor, corresponding to +45 degrees and -10 degrees respectively; When switching from flapping rotor flight mode to flapping rotor mode, the motor driving the flapping rotor to flap is turned off. At the same time, a command is issued to rotate the elastic anti-rotation plate on the servo motor drive shaft 90 degrees to a vertical position to stop the turntable component (4) from rotating. The flapping rotor, together with the flapping rotor support component (6) and the crossbar (5), pushes away the elastic anti-rotation plate under the action of rotational inertia and continues to rotate, and drives the pull wire (10) connected to the inner end of the flapping rotor pull rod (9.1.4) to rotate. Since the lower end of the pull wire (10) is connected to the turntable crossbar of the turntable component (4) that is being stopped from rotating, the distance between the upper and lower ends of the pull wire (10) increases and it is tightened, thereby pulling the flapping rotor pull rod (9.1.4) to slide inward, causing the near beam spring pin ( ) on the screw groove sleeve (9.1.2) to slide inward. 9.1.2.1) Under the action of the spring (9.1.3), it moves inward to release the passive torsion limiting tube ( 9.1.1) pin connection, the passive torsion limiting tube (9.1.1) which loses the pin constraint is also pulled inward along the flapping wing tie rod (9.1.4), and rotates along the spiral groove at the same time, so that the first torsion limiting rod (9.1.1.1) pushes the wing rib at the root of the left flapping wing (8) to flip; at this time, the flapping wing tie rod (9.1.4) slides inward to the limit to lift the far beam spring pin (9.1.2.2) at the inner end of the screw groove sleeve (9.1.2), locking the passive torsion limiting tube (9.1.1) in this state, at this time the spring (9.1.3) is in a compressed state; the flapping wing and flapping wing support component (6) and the crossbar (5) at the lower end of the support continue to rotate half a revolution under the action of rotational inertia, resulting in the connection to the turntable part. The pull wire (10) on component (4) is tightened, thereby pulling the flapping wing lever (9.1.4) to slide inward to complete the flapping wing flipping process. At this time, the kinetic energy of the flapping rotor is mainly used to drive the flapping wing to flip, and the moment of inertia and rotational speed are greatly reduced. When the crossbar (5) at the lower end of the flapping wing support component (6) rotates to the position of the elastic anti-rotation plate again, it is blocked and stays in the anti-rotation state shown. After flipping, the flapping wing flipping device is in the compressed state of the spring (9.1.3), and the flapping wings on both sides of the flapping rotor aircraft form a symmetrical arrangement state, with the leading edge consistent with the forward flight direction. At this time, if the drive motor is kept in the off state, the flapping rotor aircraft will enter the fixed-wing gliding flight mode. If the drive motor is turned on, the flapping rotor aircraft will enter the flapping wing flight mode. When switching from flapping wing mode to flapping rotor mode, a command is first issued to rotate the elastic anti-rotation plate on the servo motor component (3) to the 0° horizontal position, releasing the rotational freedom of the turntable component (4) and the crossbar (5). At this time, the pull cable (10) is released from the constraint on the flapping wing lever (9.1.4) to slide outward. The inertial force generated by the flapping of the right flapping wing (7) and the left flapping wing (8) pulls the flapping wing lever (9.1.4). 9.1.4) Slide and rotate outward to drive the left flapping wing (8) to flip and enter the flapping rotor mode and generate rotational motion and increase centrifugal force, so that the flapping wing lever (9.1.4) is fully pulled out and locked in FWR mode, completing the reverse conversion from flapping wing to flapping rotor mode, and the flapping rotor aircraft enters the flapping rotor flight mode.

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