Flapping wing air vehicle capable of sweeping double crankshafts to control flapping of double wings

Abstract

The invention discloses an ornithopter capable of sweeping double crankshafts to control double-wing flapping, and belongs to the technical field of aircrafts, the ornithopter comprises a body frame, a double-crankshaft transmission flapping mechanism, a disc cam variable sweep angle mechanism, a left flapping wing, a right flapping wing and a tail vane, the double crankshafts of the double-crankshaft transmission flapping mechanism are driven by a driving motor to rotate; the double-crankshaft is in an S shape and comprises a front crankshaft section and a rear crankshaft section, the two sections are connected with the inner ends of a left bent rocker piece and a right bent rocker piece which are coupled to the left side and the right side of the machine body frame through a left connecting rod and a right connecting rod respectively, and the outer ends of the left bent rocker piece and the right bent rocker piece are connected with wing root connecting pieces and flapping wings in sequence; the disc cam variable sweep angle mechanism comprises a disc cam, a sliding piece, an elastic reset piece and a sweep connecting rod, the sliding piece can slide front and back and makes contact with the outer contour of the disc cam through the elastic reset piece, and the disc cam rotates to drive the sliding piece to slide front and back in a reciprocating mode. And the sweeping connecting rods on the two sides drive the wing root connecting pieces and the flapping wings to perform front-and-back sweeping flapping motion.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft, and particularly relates to a flapping-wing aircraft capable of sweeping and double-crankshaft-controlled double-wing flapping. Background Art

[0002] A flapping-wing aircraft is an aircraft that imitates the flight postures of insects, birds or bats based on bionics. It has the advantages of high flight efficiency, good concealment, and the ability to flexibly change flight states. Compared with the two traditional flight methods of fixed wings and rotors, it can quickly perform high-difficulty maneuvers such as sharp turns and dives, making it more advantageous when flying in narrow spaces. Flapping-wing aircraft have broad application prospects in both military and civilian fields.

[0003] Currently, bionic flapping-wing aircraft generally adopt typical mechanisms such as single crank double rocker, crank guide rod, and double crank double rocker. Such transmission flapping mechanisms generally can only achieve simple up-and-down flapping of the aircraft's wings. Usually, the overall driving mechanism of the wings of existing flapping-wing aircraft is relatively bulky and not conducive to miniaturization; and often due to the low degree of freedom of the wings in space, the lift provided is insufficient, resulting in the inability to fly quickly and flexibly. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems that the flapping driving mechanism of most existing flapping-wing aircraft is relatively bulky and complex and the degree of freedom of the wings in space is not high, and to provide a flapping-wing aircraft capable of sweeping and double-crankshaft-controlled double-wing flapping.

[0006] A flapping-wing aircraft capable of sweeping and double-crankshaft-controlled double-wing flapping includes: a body frame 1, a double-crankshaft transmission flapping mechanism 2, a disk cam variable sweep angle mechanism 3, left and right flapping wings 4, and a tail rudder 5;

[0007] The double-crankshaft transmission flapping mechanism 2 includes: a driving motor 20a, a double crankshaft 21, a left connecting rod 22a, a right connecting rod 22b, a left bent rocker member 23a, a right bent rocker member 23b, a rocker member rotating shaft 10b, a rocker member vertical shaft, and a wing root connecting member 24;

[0008] The double crankshaft 21 is in a "positive S shape", and is divided into a front crankshaft section 21a and a rear crankshaft section 21b, and is vertically connected to the front part of the fuselage in sequence;

[0009] The driving motor 20a is fixed to the front part of the body frame 1. One end of the double crankshaft 21 is fixedly connected to the output end of the driving motor 20a, and the other end is pivotally connected to the body frame 1;

[0010] The inner and outer ends of the connecting rod are respectively hinged to the crankshaft section and the inner end of the bent rocker member;

[0011] The middle part of the bending and rocking rod is pivotally connected to the left and right sides of the body frame 1 through the bending and rocking rod rotating shaft 10b, and its outer end is hinged to the wing root connecting member 24 through the bending and rocking rod vertical shaft; the outer end of the wing root connecting member 24 is fixedly connected to the root of the flapping wing.

[0012] The described disk cam variable sweep angle mechanism 3 includes: a sweep servo 30, a disk cam 31, a sliding member 32, a sliding support shaft 10d, a transmission disk 33, a sweep connecting rod 34, and a spring 35;

[0013] The sweep servo 30 is fixedly connected to the front part of the body frame 1, and the disk cam 31 is fixedly connected to the output shaft of the sweep servo 30;

[0014] The sliding support shaft 10d is fixed to the left and right sides of the body frame 1, and both ends of the sliding member 32 are slidably connected to the middle part of the sliding support shaft 10d;

[0015] The transmission disk 33 is pivotally connected to the left and right sides of the body frame 1 in a sliding manner, and the spring 35 provides the contact force between the transmission disk 33 and the sliding member 32;

[0016] One end of the transmission disk 33 is hinged to one end of the sweep connecting rod 34 through a vertical shaft, and the other end of the sweep connecting rod 34 is hinged to the connecting platform 24b of the wing root connecting member 24 through a vertical shaft;

[0017] The outer contour of the disk cam 31 is in contact and cooperation with the limiting groove 32a on one side of the sliding member 32; the sweep servo 30 drives the disk cam 31 to rotate, the sliding member 32 moves forward and backward on the sliding support shaft 10d, and the sweep connecting rod 34 drives the flapping wing to sweep.

[0018] The described body frame 1 includes a main bracket 10 and a connecting rod 12. The front part of the connecting rod 12 is fixedly connected to the rear part of the main bracket 10, and its rear part is fixedly connected to the tail wing bracket 50 of the tail rudder 5.

[0019] The bending and rocking rod rotating shaft 10b and the sliding support shaft 10d are coaxial and symmetrically fixed to the left and right sides of the main bracket 10;

[0020] The transmission disk 33 is pivotally connected to the sliding support shaft 10d in a sliding manner. One end of it is connected to the sliding member 32, and the other end is connected to the spring 35 sleeved on the sliding support shaft 10d. The spring 35 is in a compressed state.

[0021] The left bending and rocking rod 23a and the right bending and rocking rod 23b are respectively limited and pivotally connected to the sliding support shaft 10d fixed to the left and right sides of the main bracket 10.

[0022] The crank radii of the front crankshaft section 21a and the rear crankshaft section 21b of the double crankshaft 21 are equal, and the phase difference is 180°. Let the crank length of the front crankshaft section 21a be and the crank length of the rear crankshaft section 21b be , that is ; Taking the left side as an example, assume that the projected length from the rotating shaft of the double crankshaft 21 to the rotating shaft of the bending rocker member 10b is , the projected length from the rotating shaft of the bending rocker member 10b to the hinge shaft between the left bending rocker member 23a and the left connecting rod 22a is , the projected length of the two shaft holes of the left connecting rod 22a is , so the condition for the smooth operation of the left crank-rocker mechanism is: , and the same applies to the right side.

[0023] The disc cam 31 can be divided into 4 regions, and their corresponding angles are ∠AOD, ∠AOB, ∠COD, and ∠COB, and the sum of the four is 360°; A, B, C, and D are all points on the contour of the disc cam 31. Among them, the lengths of OB and OD are R, that is, the base circle radius, the length of 0A is Rmax, and the length of 0C is Rmin, satisfying Rmax > R > Rmin.

[0024] The left and right flapping wings 4 include a left flapping wing 40 and a right flapping wing 41, and their structures are the same; the left flapping wing 40 includes a left flapping wing skeleton 40a and a left flapping wing membrane 40b wrapped on its surface; the left flapping wing connecting head 40c is fixedly connected to the inner side of the left flapping wing skeleton 40a, and is fixedly connected to the outer end of the wing root connecting member 24 through it.

[0025] The tail rudder 5 includes: a tail wing support 50, a left steering gear 51a, a right steering gear 51b, a left horizontal rudder 55a, and a right horizontal rudder 55b. Among them, the left steering gear 51a and the right steering gear 51b are fixedly connected to the tail wing support 50; the left horizontal rudder 55a and the right horizontal rudder 55b are symmetrically connected to both sides of the tail wing support 50.

[0026] The present invention provides a flapping wing aircraft capable of sweeping double crankshaft controlled double-wing flapping, belonging to the technical field of aircraft. It includes: a fuselage frame, a double crankshaft drive flapping mechanism, a disc cam variable sweep angle mechanism, left and right flapping wings, and a tail rudder. The double crankshaft drive flapping mechanism is driven by a driving motor to rotate the double crankshaft; the double crankshaft is in a "positive S shape" and includes a front crankshaft section and a rear crankshaft section. The two sections are respectively connected to the inner ends of the left bending rocker member and the right bending rocker member axially connected to the left and right sides of the fuselage frame through the left connecting rod and the right connecting rod, and their outer ends are sequentially connected to the wing root connecting member and the flapping wing; the disc cam variable sweep angle mechanism includes a disc cam, a sliding member, an elastic reset member, and a sweeping connecting rod. The sliding member can slide back and forth, and through the elastic reset member, it is in contact with the outer contour of the disc cam. The rotation of the disc cam drives the sliding member to slide back and forth, and then drives the wing root connecting member and the flapping wing to perform a flapping motion of front and rear sweeping through the sweeping connecting rods on both sides of it.

[0027] In summary, compared with the prior art, the present invention has the following beneficial effects and advantages:

[0028] 1) The flapping-wing aircraft of the present invention can achieve synchronous sweeping flapping of the two wings. By controlling the sweeping motion frequency of the flapping wings through a sweeping servo, and compounding it with the flapping motion of the flapping wings, the "elliptical" and "figure-eight" flapping motions of the wingtips can be achieved;

[0029] 2) The flapping-wing aircraft of the present invention can use the same drive source to drive the motor to simultaneously drive the double-crank transmission flapping mechanism and the disk cam variable sweep angle mechanism. The sweeping motion frequency of the disk cam variable sweep angle mechanism is controlled through a reduction mechanism;

[0030] 3) The transmission flapping mechanism and the variable sweep angle mechanism of the flapping-wing aircraft of the present invention are small and compact, which is beneficial to the miniaturization of the overall structure and the control of the overall mass of the aircraft;

[0031] 4) The amplitude of the flapping variable sweep angle motion of the flapping-wing aircraft of the present invention can be directly regulated by the Rmax and Rmin values of the disk cam. When the disk cam rotates to an effective radius of R, the flapping wings of the aircraft are in a 0° sweep angle state, and the duration ratio of the forward and backward sweeping motions can be directly adjusted by adjusting the layout ratio of the disk cam. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the overall structure of a flapping-wing aircraft with a sweepable double-crankshaft controlled double-wing flapping of the present invention;

[0033] Figure 2 is a three-dimensional structure schematic diagram of the airframe frame of a flapping-wing aircraft with a sweepable double-crankshaft controlled double-wing flapping of the present invention;

[0034] Figure 3 is an exploded structure schematic diagram of the airframe frame of a flapping-wing aircraft with a sweepable double-crankshaft controlled double-wing flapping of the present invention;

[0035] Figure 4 is a three-dimensional schematic diagram of the double-crankshaft transmission flapping mechanism of a flapping-wing aircraft with a sweepable double-crankshaft controlled double-wing flapping of the present invention;

[0036] Figure 5 is a schematic diagram of the specific structure of the double-crankshaft of a flapping-wing aircraft with a sweepable double-crankshaft controlled double-wing flapping of the present invention;

[0037] Figure 6 is a schematic diagram of the operating principle of the double-crankshaft transmission flapping mechanism of a flapping-wing aircraft with a sweepable double-crankshaft controlled double-wing flapping of the present invention;

[0038] Figure 7 is a three-dimensional schematic diagram of the disk cam variable sweep angle mechanism of a flapping-wing aircraft with a sweepable double-crankshaft controlled double-wing flapping of the present invention;

[0039] Figure 8It is a schematic diagram of the specific proportional dimension structure of the disk cam of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention;

[0040] Figure 9 It is a three-dimensional structure schematic diagram of the flapping wings of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention;

[0041] Figure 10 It is a schematic diagram of the connection mode between the flapping wings and the transmission flapping mechanism of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention;

[0042] Figure 11 It is a schematic diagram of the specific structure of the horizontal tail wing of the flapping-wing aircraft with variable sweep angle of the double wings of the present invention;

[0043] Figure 12 It is a schematic diagram of the variable sweep angle movement of the double wings of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention Figure 1 ;

[0044] Figure 13 It is a schematic diagram of the variable sweep angle movement of the double wings of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention Figure 2 ;

[0045] Figure 14 It is a schematic diagram of the variable sweep angle movement of the double wings of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention Figure 3 ;

[0046] Figure 15 It is a schematic diagram of the variable sweep angle movement of the double wings of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention Figure 4 ;

[0047] Figure 16 It is a schematic diagram of the dive state of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention;

[0048] Figure 17 It is a schematic diagram of the upstroke state of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention;

[0049] Figure 18 It is a schematic diagram of the downstroke state of the flapping-wing aircraft with a sweepable double crankshaft for controlling the double-wing flapping of the present invention.

[0050] In the attached drawings

[0051] 1. Airframe frame; 10. Main frame; 10a. Front support; 10b. Rotating shaft of the bent rocker rod; 10c. Rear support; 10d. Sliding support shaft; 10e. Middle support; 10f. Fixed groove; 11. Connecting and fixing piece; 12. Connecting rod;

[0052] 2. Double-crankshaft drive flapping mechanism; 20. Motor bracket; 20a. Driving motor; 20b. Pinion gear; 20c. Double-layer gear; 20d. Large gear; 20e. Fixed concave platform; 20f. Fixed screw; 21. Double-crankshaft; 21a. Front crankshaft section; 21b. Rear crankshaft section; 22a. Left connecting rod; 22b. Right connecting rod; 23a. Left bent rocker arm; 23b. Right bent rocker arm; 24. Wing root connecting piece; 24a. Flapping wing fixing groove; 24b. Connecting platform;

[0053] 3. Disk cam variable sweep angle mechanism; 30. Sweep servo; 31. Disk cam; 32. Sliding part; 32a. Limit groove; 33. Transmission disk; 34. Sweep connecting rod; 35. Spring;

[0054] 4. Left and right flapping wings; 40. Left flapping wing; 40a. Left flapping wing skeleton; 40b. Left flapping wing membrane; 40c. Left flapping wing connecting head; 41. Right flapping wing;

[0055] 5. Tail rudder; 50. Tail wing bracket; 51a. Left servo; 51b. Right servo; 52a. Left rudder arm; 52b. Right rudder arm; 53a. Left pull rod; 53b. Right pull rod; 54a. Left connecting piece; 54b. Right connecting piece; 55a. Left horizontal rudder; 55b. Right horizontal rudder. Detailed implementation mode

[0056] Embodiment 1

[0057] A flapping-wing aircraft capable of sweeping and double-crankshaft-controlled double-wing flapping, comprising: airframe frame 1, double-crankshaft drive flapping mechanism 2, disk cam variable sweep angle mechanism 3, left and right flapping wings 4, and tail rudder 5, wherein:

[0058] The double-crankshaft drive flapping mechanism 2 includes: driving motor 20a, double-crankshaft 21, left connecting rod 22a, right connecting rod 22b, left bent rocker arm 23a, right bent rocker arm 23b, rocker arm rotating shaft 10b, rocker arm vertical shaft, and wing root connecting piece 24;

[0059] The double-crankshaft 21 is in a "positive S shape", divided into a front crankshaft section 21a and a rear crankshaft section 21b, and is vertically connected to the front of the fuselage according to the front and rear;

[0060] The driving motor 20a is fixed to the front end of the airframe frame 1, the front end of the double-crankshaft 21 is fixedly connected to the output end of the driving motor 20a, and the rear end is axially connected to the airframe frame 1;

[0061] The inner ends of the left connecting rod 22a and the right connecting rod 22b are respectively hinged to the front crankshaft section 21a and the rear crankshaft section 21b, and their outer ends are respectively hinged to the inner sides of the left bent rocker arm 23a and the right bent rocker arm 23b;

[0062] The middle parts of the left bent rocker rod 23a and the right bent rocker rod 23b are pivotally connected to the left and right sides of the body frame 1 through the bent rocker rod rotating shaft 10b, and their outer ends are hinged to the wing root connecting member 24 through the bent rocker rod vertical shaft; the outer end of the wing root connecting member 24 is fixedly connected to the root of the flapping wing.

[0063] The described disk cam variable sweep angle mechanism 3 includes: a sweep servo 30, a disk cam 31, a sliding member 32, a sliding support shaft 10d, a transmission disk 33, a sweep connecting rod 34, and a spring 35.

[0064] The sweep servo 30 is fixedly connected in the fixed groove 10f at the front of the body frame 1, and the disk cam 31 is fixedly connected to the output shaft of the sweep servo 30.

[0065] The sliding support shaft 10d is fixed to the left and right sides of the body frame 1, and both ends of the sliding member 32 are slidably connected to the middle part of the sliding support shaft 10d.

[0066] The transmission disk 33 is slidably pivotally connected to the left and right sides of the body frame 1, the transmission disk 33 is connected to both ends of the sliding member 32, and the spring 35 provides the contact force between the two. One end of the spring is connected to the body frame 1 and the other end is connected to the transmission disk 33.

[0067] The outer side of the described transmission disk 33 is hinged to the front end of the sweep connecting rod 34 through a vertical shaft, and the rear end of the sweep connecting rod 34 is hinged to the connecting platform 24b of the wing root connecting member 24 through a vertical shaft.

[0068] The outer contour of the disk cam 31 is in contact and cooperation with the limiting groove 32a at the rear side of the sliding member 32; the sweep servo 30 drives the disk cam 31 to rotate, the sliding member 32 moves forward and backward on the sliding support shaft 10d, drives the transmission disk 33 to slide forward and backward, and drives the wing root connecting member 24 and the flapping wing to perform sweep movement through the sweep connecting rod 34.

[0069] The described body frame 1 includes a main bracket 10, a connection and fixing member 11, and a connecting rod 12. The front part of the connecting rod 12 is fixedly connected to the rear end of the main bracket 10 through the connection and fixing member 11, and its rear end is fixedly connected to the tail wing bracket 50 of the tail rudder 5; the main bracket 10 includes front brackets 10a on the left and right sides of its front part, rear brackets 10c on the left and right sides of its rear part, and a fixed groove 10f in the middle part; the bent rocker rod rotating shaft 10b and the sliding support shaft 10d are respectively fixedly connected to the front brackets 10a and the rear brackets 10c.

[0070] The bottom plate, bracket on the main bracket 10, and the connection and fixing member 11 can be made of a polyester material with a high specific strength and specific stiffness, and the connecting rod 12 can be a hollow connecting rod made of carbon fiber material.

[0071] The rotating shaft 10b of the bending rocking rod and the sliding support shaft 10d are coaxial and symmetrically fixed on the left and right sides of the main bracket 10; the transmission disc 33 is slidably axially connected to the sliding support shaft 10d, its rear end is connected to the sliding member 32, and its front end is connected to a spring 35 sleeved on the sliding support shaft 10d. The spring 35 is in a compressed state, and the other end of the spring is connected to the front side of the rear bracket 10c of the machine body frame 1.

[0072] The left bending rocking rod 23a and the right bending rocking rod 23b are symmetrically and limit axially connected to the sliding support shaft 10d fixed on the left and right sides of the main bracket 10, that is, they are only axially connected and do not slide back and forth.

[0073] A gear reduction mechanism is also provided between the drive motor 20a of the double crankshaft drive flapping mechanism 2 and the double crankshaft 21. It includes a motor bracket 20, a pinion 20b, a double-layer gear 20c, and a large gear 20d;

[0074] The motor bracket 20 is fixedly connected to the front end of the main bracket 10 through a fixing screw 20f. The drive motor 20a is fixedly connected to the motor bracket 20, and its output shaft is fixedly connected to the pinion 20b; the double-layer gear 20c and the large gear 20d are axially connected to the motor bracket 20 through pins. The pinion 20b meshes with the large-tooth-number end of the double-layer gear 20c, and the large gear 20d meshes with the small-tooth-number end of the double-layer gear 20c; the front end of the double crankshaft 21 is connected to the fixed concave platform 20e at the center of the large gear 20d by a pin, and the rear end of the double crankshaft 21 is axially connected to the middle bracket 10e located in the middle of the main bracket 10.

[0075] See the appendix Figure 6 , the crank radii of the front crankshaft section 21a and the rear crankshaft section 21b of the double crankshaft 21 are equal, and the phase difference is 180°. Let the crank length of the front crankshaft section 21a be , and the crank length of the rear crankshaft section 21b be , that is ; taking the left side as an example, let: the projected length from the rotating shaft of the double crankshaft 21 to the rotating shaft 10b of the bending rocking rod be , the projected length from the rotating shaft 10b of the bending rocking rod to the hinge shaft between the left bending rocking rod 23a and the left connecting rod 22a be , and the projected length of the two shaft holes of the left connecting rod 22a be , so the condition for the smooth operation of the left crank rocker mechanism is: , and the same is true for the right side;

[0076] In actual use, it can be selected not to change the length, and by changing , , The length can quickly adjust parameters such as the flapping amplitude of the flapping wing and the extreme positions of the up-and-down flapping of the flapping wing. That is, when the double crankshaft 21 rotates, it can drive the movement of two sets of crank-rocker mechanisms on the left and right with the same structure but a crank phase difference of 180°. The left bent rocker rod 23a and the right bent rocker rod 23b are the so-called rockers.

[0077] See Figure 8 , the disc cam 31 can be divided into 4 regions, and the corresponding angles of the 4 regions are ∠AOD, ∠AOB, ∠COD, and ∠COB respectively. In this embodiment, ∠AOD, ∠AOB, ∠COD, and ∠COB are all 90°. The corresponding angles of the positive sweep angle are ∠AOD and ∠AOB, and the sum of the two is 180°. The corresponding angles of the negative sweep angle are ∠COD and ∠COB, and the sum of the two is 180°.

[0078] The angular velocity of the rotation of the disc cam 31 is constant. Therefore, in this embodiment, the positive sweep angle state and the negative sweep angle state each account for half of the sweep period; A, B, C, and D are all points on the contour of the disc cam 31.

[0079] Among them, the lengths of OB and OD are R, that is, the base circle radius. That is, when B and D on the disc cam 31 are in contact with the limit groove 32a, the flapping wing is in a state where the sweep angle is 0°. See Appendix Figure 13 and Appendix Figure 15 ;

[0080] Among them, the length of 0A is Rmax. That is, when A on the disc cam 31 is in contact with the limit groove 32a, the flapping wing is in the state of the front limit position of the sweep motion. See Appendix Figure 12 ;

[0081] Among them, the corresponding length of 0C is Rmin. That is, when C on the disc cam 31 is in contact with the limit groove 32a, the flapping wing is in the state of the rear limit position of the sweep motion. See Appendix Figure 14 ;

[0082] Satisfy Rmax > R > Rmin. Keeping other components unchanged, the amplitude of the forward and backward sweep of the flapping wing can be changed by changing the sizes of Rmax and Rmin in the disc cam 31, and the duration distribution of the forward sweep and backward sweep of the flapping wing can also be adjusted by adjusting the proportion of ∠AOD, ∠AOB, ∠COD, and ∠COB in 360°.

[0083] The left and right flapping wings 4 include a left flapping wing 40 and a right flapping wing 41, and the two have the same structure; the left flapping wing 40 includes a left flapping wing skeleton 40a made of carbon fiber and a left flapping wing film 40b with light weight and high density wrapped on its surface; the left flapping wing connecting head 40c is fixedly connected to the inner side of the left flapping wing skeleton 40a, and is fixedly connected to the flapping wing fixing groove 24a of the wing root connecting member 24 through the left flapping wing connecting head 40c. The right side also uses this connection method.

[0084] The rudder 5 includes: a fin support 50, a left servo 51a, a right servo 51b, a left rudder arm 52a, a right rudder arm 52b, a left pull rod 53a, a right pull rod 53b, a left connecting member 54a, a right connecting member 54b, a left horizontal rudder 55a, and a right horizontal rudder 55b. The left servo 51a and the right servo 51b are fixedly connected to the left and right sides of the front part of the fin support 50. The left horizontal rudder 55a and the right horizontal rudder 55b have the same structure and are symmetrically connected to the left and right sides of the rear part of the fin support 50. The left connecting member 54a on the left horizontal rudder 55a is connected to the left rudder arm 52a through the left pull rod 53a. The left rudder arm 52a is installed on the output shaft of the left servo 51a and is driven by it. The connection method of the right horizontal rudder 55b to the right servo 51b is the same as that on the left side.

[0085] Embodiment 2

[0086] In this embodiment, the spring 35 is in a compressed state, providing the contact force between the transmission disc 33 and the sliding member 32. The spring 35 and the sliding member 32 are respectively located on the front and rear sides of the transmission disc 33.

[0087] In some other embodiments: the spring 35 is in a stretched state, but the spring 35 and the sliding member 32 need to be located on the same side of the transmission disc 33. One end of the spring 35 is fixedly connected to the sliding member 32, and the other end is axially connected to the body frame 1 in an embedded manner.

[0088] The transmission disc 33 is slidably axially connected to the left and right sides of the body frame 1. Its inner ends are connected to the left and right ends of the sliding member 32. The stretched state of the spring 35 provides the contact force between the transmission disc 33 and the sliding member 32.

[0089] The specific process of the mechanism movement of a flapping-wing aircraft with a sweepable double crankshaft for controlling double-wing flapping according to the present invention is as follows:

[0090] During operation, the driving motor 20a drives the small gear 20b to rotate, and successively drives the double-layer gear 20c and the large gear 20d to rotate, thereby driving the "positive S-shaped" double crankshaft 21 fixedly connected to one end of the large gear 20d to rotate. The front crankshaft section 21a and the rear crankshaft section 21b of the double crankshaft 21 form two cranks with a phase difference of 180°. They respectively drive the left bent rocker member 23a and the right bent rocker member 23b symmetrically connected to both sides of the fuselage to swing reciprocally through the left connecting rod 22a and the right connecting rod 22b, driving the wing root connecting members 24 on both sides to swing up and down, and further driving the left and right flapping wings 4 to flap.

[0091] When the flapping wings flap, the left bent rocker member 23a and the wing root connecting member 24 rotate reciprocally around the rocker member rotating shaft 10b, which will drive the sweep link 34 and the transmission disc 33 connected thereto to rotate around the sliding support shaft 10d together. The structure on the right side is the same as that on the left side and moves synchronously.

[0092] Under the elastic force of the spring 35, the transmission discs 33 on the left and right sides are in close contact with the front ends of both sides of the sliding member 32, and the limiting groove 32a on the rear side of the sliding member 32 is in close contact with the outer contour of the disc cam 31. During the flapping process of the flapping wings, the disc cam 31 is controlled to rotate by the sweeping servo 30, so that the sliding member 32 reciprocates back and forth along the sliding support shaft 10d. The wing root connectors 24 on both sides are driven by the transmission discs 33 and the sweeping connecting rods 34 on both sides to rotate back and forth synchronously around the bent rocker arms hinged thereto, thereby completing the synchronous front and back sweeping motion of the left and right flapping wings. The compounding of the sweeping motion and the flapping motion in space can realize the "elliptical" and "figure-eight" flapping motions of the flapping wings.

[0093] For the specific operation process of the variable sweep angle mechanism 3 of the disc cam, reference can be made to Appendix Figure 8 Appendix Figure 12 - Appendix Figure 15 When the sweeping servo 30 drives the disc cam 31 to rotate, four points A, B, C, and D on it come into contact with the limiting groove 32a of the sliding member 32 in sequence, as shown in Appendix Figure 12 Appendix Figure 13 Appendix Figure 14 Appendix Figure 15 respectively. The variable sweep angle motion states of the variable sweep angle mechanism 3 of the disc cam in the appendices correspond in sequence. The contact position between the disc cam 31 and the sliding member 32 changes from A to B, B to C, C to D, and finally back to A, which completes a complete front and back sweeping motion. Of course, A, B, C, and D can all be used as the starting points of the front and back sweeping motion.

[0094] When the aircraft is flying, the left horizontal rudder 55a and the right horizontal rudder 55b can be controlled to lift and lower respectively by the left servo 51a and the right servo 51b to control the flight actions of the aircraft such as pitch, yaw, roll, glide, and dive.

[0095] The flapping-wing aircraft of the present invention can realize the synchronous sweeping and flapping of the two wings. By controlling the sweeping motion frequency by the sweeping servo and compounding it with the flapping motion, the "elliptical" and "figure-eight" flapping motions of the wing tips can be realized, providing sufficient flight power for the aircraft. It is also possible to use the same drive source to drive the double crank transmission flapping mechanism 2 and the variable sweep angle mechanism 3 of the disc cam to move simultaneously, and control the sweeping motion frequency of the variable sweep angle mechanism 3 of the disc cam through a reduction mechanism to realize the "elliptical" or "figure-eight" flapping motion of the wing tips. The amplitude of the variable sweep angle motion can be directly regulated by the Rmax and Rmin values of the disc cam, and the duration ratio of the forward and backward sweeping motions can be directly adjusted by adjusting the layout ratio of the disc cam. In summary, the transmission flapping mechanism and the variable sweep angle mechanism of this flapping-wing aircraft are small and compact, which is beneficial to the miniaturization of the overall structure and the control of the overall mass of the aircraft.

Claims

1. A flapping-wing aircraft capable of sweeping a double crankshaft to control the flapping of two wings, comprising: Airframe frame (1), double crankshaft transmission flapping mechanism (2), disc cam variable sweep angle mechanism (3), left and right flapping wings (4), and tail rudder (5); The double crankshaft transmission flapping mechanism (2) comprises: a driving motor (20a), a double crankshaft (21), a left connecting rod (22a), a right connecting rod (22b), a left curved rocker component (23a), a right curved rocker component (23b), a curved rocker component rotating shaft (10b), a curved rocker component vertical shaft and a wing root connecting component (24); The double crankshaft (21) is in a "positive S-shape", divided into a front crankshaft section (21a) and a rear crankshaft section (21b), and connected to the front part of the fuselage along the front and rear vertical axes; The drive motor (20a) is fixed to the front of the machine frame (1); one end of the double crankshaft (21) is fixedly connected to the output end of the drive motor (20a), and the other end is axially connected to the machine frame (1); The inner and outer ends of the connecting rod are respectively hinged to the inner ends of the crankshaft section and the bending rocker member; The middle part of the bending rocker is axially connected to the left and right sides of the body frame (1) through the bending rocker rotating shaft (10b), and the outer end of the bending rocker is hinged to the wing root connecting member (24) through the bending rocker vertical shaft; the outer end of the wing root connecting member (24) is fixedly connected to the root of the flapping wing; The disc cam variable sweep angle mechanism (3) comprises: a sweep servo (30), a disc cam (31), a sliding member (32), a sliding support shaft (10d), a transmission plate (33), a sweep connecting rod (34) and a spring (35); The sweeping servo (30) is fixedly connected to the front part of the machine body frame (1), and the disc cam (31) is fixedly connected to the output shaft of the sweeping servo (30); The sliding support shaft (10d) is fixed to the left and right sides of the machine body frame (1), and the two ends of the sliding member (32) are slidably connected to the middle of the sliding support shaft (10d); The transmission plate (33) is slidably connected to the left and right sides of the machine frame (1), and the spring (35) provides contact force between the transmission plate (33) and the sliding member (32); The outer side of the transmission plate (33) is hinged to one end of a sweep link (34) via a vertical shaft, and the other end of the sweep link (34) is hinged to a connecting platform (24b) of a wing root connecting member (24) via a vertical shaft; The outer contour of the disc cam (31) contacts and cooperates with a limit groove (32a) on one side of the sliding member (32); the sweep servo (30) drives the disc cam (31) to rotate, the sliding member (32) moves forward and backward on the sliding support shaft (10d), and the sweep connecting rod (34) drives the flapping wing to sweep.

2. A flapping-wing aircraft capable of sweeping double crankshafts to control the flapping of double wings according to claim 1, characterized in that: The fuselage frame (1) comprises a main support (10) and a connecting rod (12), wherein the front portion of the connecting rod (12) is fixedly connected to the rear portion of the main support (10), and the rear portion of the connecting rod (12) is fixedly connected to the tail wing support (50) of the tail rudder (5).

3. A flapping-wing aircraft capable of sweeping a double crankshaft to control the flapping of both wings according to claim 1 or 2, characterized in that: The bending rocker member rotation axis (10b) and the sliding support axis (10d) are coaxial and symmetrically fixed to the left and right sides of the main bracket (10); The transmission plate (33) is slidably connected to the sliding support shaft (10d), one end of which is connected to the sliding member (32), and the other end of which is connected to a spring (35) sleeved on the sliding support shaft (10d), wherein the spring (35) is in a compressed state.

4. A flapping-wing aircraft capable of sweeping double crankshafts to control the flapping of double wings according to claim 3, characterized in that: The left-bend rocker component (23a) and the right-bend rocker component (23b) are respectively limitedly axially connected to the sliding support shafts (10d) fixedly connected to the left and right sides of the main bracket (10).

5. A flapping-wing aircraft capable of sweeping a double crankshaft to control the flapping of two wings according to claim 4, characterized in that: The crank radii of the front crankshaft section (21a) and the rear crankshaft section (21b) of the double crankshaft (21) are equal, and the phase difference is 180 degrees. Assuming that the crank length of the front crankshaft section (21a) is , the crank length of the rear crankshaft section (21b) is ,Right now Taking the left side as an example, assume that the projected length from the rotation axis of the double crankshaft (21) to the rotation axis (10b) of the bending rocker member is The projected length from the bending rocker member rotation axis (10b) to the hinge axis between the left bending rocker member (23a) and the left connecting rod (22a) is , the projected length of the two axial holes of the left connecting rod (22a) is , so the condition for the smooth operation of the left crank rocker mechanism is: , the same applies to the right side.

6. A flapping-wing aircraft capable of sweeping double crankshafts to control flapping of double wings according to claim 5, characterized in that: The disc cam (31) can be divided into four areas, whose corresponding angles are ∠AOD, ∠AOB, ∠COD, and ∠COB, and the sum of the four is 360°; A, B, C, and D are all points on the contour of the disc cam (31), wherein the lengths of OB and OD are R, i.e., the base circle radius, the length of 0A is Rmax, and the length of 0C is Rmin, satisfying Rmax>R>Rmin.

7. A flapping-wing aircraft capable of sweeping double crankshafts to control flapping of double wings according to claim 4, 5 or 6, characterized in that: The left and right flapping wings (4) comprise a left flapping wing (40) and a right flapping wing (41), and the two have the same structure. The left flapping wing (40) comprises a left flapping wing frame (40a) and a left flapping wing membrane (40b) wrapped around the surface of the left flapping wing frame. The inner side of the left flapping wing frame (40a) is fixedly connected to a left flapping wing connector (40c), which is fixedly connected to the outer end of a wing root connector (24) through the left flapping wing frame (40a).

8. A flapping-wing aircraft capable of sweeping double crankshafts to control flapping of double wings according to claim 7, characterized in that: The tail rudder (5) comprises: a tail support (50), a left servo (51a), a right servo (51b), a left horizontal rudder (55a), and a right horizontal rudder (55b), wherein the left servo (51a) and the right servo (51b) are fixedly connected to the tail support (50); and the symmetry axes of the left horizontal rudder (55a) and the right horizontal rudder (55b) are connected to two sides of the tail support (50).

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