A secondary rotor deployment mechanism and method for a coaxial dual-rotor UAV

Abstract

This invention discloses a secondary rotor deployment mechanism and method for a coaxial dual-rotor unmanned aerial vehicle (UAV). The UAV's phase arm is equipped with an upper rotor primary deployment mechanism and a lower rotor secondary deployment mechanism. The lower rotor secondary deployment mechanism includes a lower rotor, a secondary elastic mechanism, and a condition-limiting propeller clamp. The support body of the secondary elastic mechanism is connected to the UAV's phase arm. The secondary elastic mechanism is rotatably connected to the condition-limiting propeller clamp, and the condition-limiting propeller clamp is fixedly connected to the lower rotor. The secondary rotor deployment mechanism and method provided by this invention are compact, reliable, and enable the lower rotor of the UAV to deploy in two stages, transforming it from a retracted state to a working state. This deployment mechanism effectively avoids the risk of rotor misfires after the UAV is launched from the launch tube.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a secondary rotor deployment mechanism and method for a coaxial dual-rotor UAV. Background Technology

[0002] When a coaxial dual-rotor drone (hereinafter referred to as a drone. Unless otherwise specified, the drone referred to in the following text refers to a coaxial dual-rotor drone) takes off from the ground using a landing gear, the upper and lower rotors can be manually deployed, and generally no special automatic rotor deployment mechanism is required.

[0003] With the continuous development of drones and the increasing adaptability requirements of various application scenarios, especially the requirement for drones to have launch tube functionality, the rotors of drones must be folded and stowed before takeoff. After launch, the rotors must automatically deploy. However, a challenge lies in the fact that the upper and lower rotors are coaxially designed with a small distance between them. When the upper and lower rotors rotate in opposite directions, they interfere with each other, resulting in a high risk of rotor flapping. Damaged rotors due to flapping directly affect the drone's flight and greatly increase the probability of a crash.

[0004] The automatic deployment function of drone rotors has become an urgent problem to be solved. Currently, drone rotors are deployed by a deployment mechanism that allows the upper and lower rotors to unfold from their folded state simultaneously or sequentially with a time difference. The disadvantage of this method is that when the upper and lower rotors unfold at the same time or sequentially with a time difference, the flapping of the rotors at the moment of startup and the disturbance of the incoming airflow have a large unpredictable and uncontrollable impact on the upper and lower rotors as they rotate in opposite directions. The upper and lower rotors may interfere with each other, so there is still a great risk of rotor flapping, which may lead to a crash risk. Summary of the Invention

[0005] In view of this, the present invention proposes a secondary rotor deployment mechanism and method for a coaxial dual-rotor unmanned aerial vehicle.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A secondary deployment mechanism and method for the rotors of a coaxial dual-rotor unmanned aerial vehicle (UAV) is provided on the phase arm of the UAV body. The upper rotor primary deployment mechanism and the lower rotor secondary deployment mechanism are provided on the phase arm of the UAV body. The lower rotor secondary deployment mechanism includes a lower rotor, a secondary elastic mechanism and a conditional limiting propeller clip.

[0008] The condition-limiting propeller clamp includes a limiting propeller clamp body, a boss, a round bottom groove, a secondary deployment limiting part, and a rotor upward limiting part; a lower rotor is connected to one side of the limiting propeller clamp body; a boss is provided at the lower end of the other side of the limiting propeller clamp body; a secondary deployment limiting part and a rotor upward limiting part are respectively provided at the lower end and the top end of the other side end face of the limiting propeller clamp body; a round bottom groove is provided at the lower end of the secondary deployment limiting part on the other side end face of the limiting propeller clamp body.

[0009] The secondary elastic mechanism includes a support body, a contact head through hole, and an elastically retractable contact head assembly; one side of the support body is rotatably connected to a limit propeller clamp body; the other side of the support body has a contact head through hole in a transverse direction, and the elastically retractable contact head assembly is provided in the contact head through hole; one end of the elastically retractable contact head assembly extends through the contact head through hole, and when the elastically retractable contact head assembly is in its natural state, it abuts against the round bottom groove; the other end of the elastically retractable contact head assembly is connected to the inner wall of the outer end of the contact head through hole or the phase arm of the UAV body.

[0010] Preferably, one side of the limiting rotor clamp body is integrally connected to the lower rotor.

[0011] Preferably, one side of the limiting propeller clamp body is detachably connected to the lower rotor.

[0012] Preferably, a rotor mounting groove is longitudinally opened at one end of the limiting rotor clamp body, and a rotor mounting through hole with the front and rear ends connected is opened on the limiting rotor clamp body corresponding to the position of the rotor mounting groove; the connecting end of the lower rotor is embedded in the rotor mounting groove; the rotor mounting hole of the limiting rotor clamp body and the mounting hole of the connecting end of the lower rotor are interconnected, and bolts are threadedly connected in the interconnected mounting holes and the bolts are fastened with nuts.

[0013] Preferably, the other end face of the limiting paddle clamp body is an arc-shaped end face.

[0014] Preferably, the secondary unfolding limiting part is an arc-shaped limiting part that protrudes from the other end face of the limiting paddle clamp body.

[0015] Preferably, the rotor lifting limiting part is a cuboid lifting limiting part that protrudes from the other end face of the limiting rotor clamp body; the outer end face of the cuboid lifting limiting part is inclined upward from the outside to the inside.

[0016] Preferably, one end of the support body has a longitudinally penetrating mounting groove, which is interconnected with the contact head through hole; the support body has a through mounting hole corresponding to the mounting groove, with the front and rear ends connected; the other side of the limiting propeller clamp body has a connecting through hole at the middle of the upper end, with the front and rear ends connected; the limiting propeller clamp body is embedded in the mounting groove, and the mounting through hole and the connecting through hole of the limiting propeller clamp body are interconnected, with a connecting screw passing through the two interconnected holes, and a nut being externally threaded onto one end of the connecting screw extending out of the support body.

[0017] Preferably, the resiliently telescopic contact head assembly includes a plug, a spring, and a contact head; the plug, spring, and contact head are connected in sequence, the contact head extends through the contact head through hole, the contact head engages with the round bottom groove when the spring is in its natural state, and the plug is connected to the inner wall of the outer end of the contact head through hole of the supporting body or the phase arm of the UAV body.

[0018] Preferably, a weight-reducing groove is provided on the upper end face of the other side of the supporting main body; a weight-reducing groove is provided on the front end face of the other side of the limiting paddle clamp body.

[0019] The present invention also provides a method for deploying the secondary deployment mechanism of the rotor of a coaxial dual-rotor unmanned aerial vehicle, comprising the following steps:

[0020] S1: When the drone is inside the launch tube, both the upper and lower rotors are in a vertical position and are folded and stored inside the launch tube; the upper rotor of the drone compresses the torsion spring on the upper rotor connection part, and the boss of the lower rotor compresses the contact head.

[0021] S2: After the UAV is launched from the tube, the upper rotor is deployed to 80° to 90° due to the torsion spring; the contact head is pushed open by the spring due to the release of the elastic potential energy of the spring. During the process of pushing open, the contact head pushes the condition limit propeller clamp and the lower rotor to swing upward along the connecting screw. When the contact head is pushed open to the maximum, the lower rotor is deployed for the first time with an deployment angle of 45°. The outer end of the contact head is exactly matched with the round bottom groove of the condition limit propeller clamp.

[0022] S3: After the drone starts its motor, the upper and lower rotors begin to rotate. The rotation of the lower rotor causes the condition limit rotor clip and the lower rotor to generate centrifugal force. The centrifugal force causes the condition limit rotor clip and the lower rotor to generate counterclockwise torque. Under the action of the torque, the condition limit rotor clip and the lower rotor rotate around the connecting screw, pushing and compressing the contact head for the second time. When the torque reaches the threshold, the secondary deployment limit part completely pushes open the contact head, and the contact head is compressed back to the low position. When the secondary deployment limit part completely passes the contact head, the elastic potential energy of the spring is released, the contact head springs open for the second time, and the lower rotor flaps upward to achieve the second deployment of the lower rotor. Due to the action of centrifugal force, the lower rotor is deployed to 90°.

[0023] S4: After the lower rotor is deployed for the second time, without sufficient external force, the upper surface of the secondary deployment limit part cannot cross the contact head of the secondary elastic mechanism in the opposite direction. The secondary deployment limit part is the lower limit of the rotor flapping angle. After the lower rotor is deployed for the second time, the outer side of the rotor upward limit part cannot cross the outer wall of the phase arm of the UAV body, which restricts the lower rotor from continuing to flap counterclockwise at a large angle. The rotor upward limit part is the upper limit of the rotor flapping angle.

[0024] Compared with existing technologies, the beneficial effects of this invention are:

[0025] (1) When the UAV is launched from the tube, the upper rotor and the lower rotor complete one deployment at the same time. The upper rotor is deployed to 80°, while the lower rotor can only be deployed to 45° due to the limitation of the second deployment limit part. At this time, because there is a difference in the deployment angle between the upper and lower rotors, it can effectively avoid the upper and lower rotors from flapping due to rotating in opposite directions.

[0026] (2) When the rotation speed of the upper and lower rotors increases, the upper rotor is thrown to a horizontal angle due to centrifugal force, and the lower rotor also swings upward due to centrifugal force. When the upward swing force of the lower rotor reaches the threshold, the lower rotor passes the limit of the secondary deployment limit and reaches the horizontal position. During this period, since both the upper and lower rotors reach high speed and are thrown to the horizontal, there is no possibility of propulsion. Therefore, this lower rotor secondary deployment mechanism achieves the purpose of no propulsion during the period from launch to full rotor deployment of the UAV.

[0027] (3) The automatic deployment structure of the lower rotor of this secondary deployment mechanism is simple and purely mechanical, requiring no additional electronic, electrical and software control.

[0028] (4) The structure of this lower rotor secondary deployment mechanism is simple, but it can have multiple functions, namely, multiple elastic potential energy release, secondary limit (to prevent the lower rotor from over-deploying in the first deployment), and tertiary limit (to prevent the lower rotor from drooping).

[0029] (5) The design of the secondary deployment mechanism of the lower rotor is ingenious, simple, small in size and light in weight. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall storage structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the overall structure of the present invention after being unfolded in one step;

[0032] Figure 3 for Figure 2 Enlarged view of part A in the image;

[0033] Figure 4 This is a schematic diagram of the overall secondary unfolded structure of the present invention;

[0034] Figure 5 for Figure 4 Enlarged view of part B in the image;

[0035] Figure 6 This is a schematic diagram of the lower rotor in its retracted state according to the present invention;

[0036] Figure 7 This is a schematic diagram of the completed first deployment of the lower rotor of the present invention;

[0037] Figure 8 This is a schematic diagram of the lower rotor during its second deployment according to the present invention;

[0038] Figure 9 This is a schematic diagram of the lower rotor in the completed second deployment state of the present invention;

[0039] Figure 10 This is a schematic diagram of the lower rotor flapping angle lower limit state structure of the present invention;

[0040] Figure 11 This is a schematic diagram of the upper limit state structure of the lower rotor flapping angle according to the present invention;

[0041] Figure 12 This is a schematic diagram of the secondary elastic force mechanism and condition-limiting paddle clamp structure of the present invention;

[0042] Figure 13 This is a schematic diagram of the secondary elastic force mechanism and condition-limiting paddle clamp structure of the present invention;

[0043] Figure 14 This is a top view of the secondary elastic mechanism and condition-limiting paddle clamp of the present invention;

[0044] Figure 15 for Figure 12 Sectional view along line AA in the middle;

[0045] Figure 16 This is a schematic diagram of the secondary elastic force mechanism of the present invention;

[0046] Figure 17 This is a schematic diagram of the secondary elastic force mechanism of the present invention;

[0047] Figure 18 This is a front view of the secondary elastic mechanism of the present invention;

[0048] Figure 19 This is a left view of the secondary elastic mechanism of the present invention;

[0049] Figure 20 This is a right view of the secondary elastic mechanism of the present invention;

[0050] Figure 21 This is a schematic diagram of the condition-limiting paddle clamp structure of the present invention;

[0051] Figure 22 This is a schematic diagram of the condition-limiting paddle clamp structure of the present invention;

[0052] Figure 23 This is a front view of the condition-limiting paddle clamp of the present invention.

[0053] In the diagram: 1. Lower rotor; 2. Conditional limiting propeller clamp; 21. Limiting propeller clamp body; 201. Arc-shaped end face; 22. Connecting through hole; 23. Boss; 24. Round bottom groove; 25. Secondary deployment limiting part; 26. Rotor upward limiting part; 27. Rotor mounting groove; 28. Rotor mounting through hole; 29. ​​Weight reduction groove; 3. Bolt; 4. Nut; 5. UAV body; 6. Support body; 7. Mounting groove; 8. Mounting through hole; 9. Contact head through hole; 10. Plug; 11. Spring; 12. Contact head; 13. Connecting screw; 14. Upper rotor. Detailed Implementation

[0054] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0055] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0056] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0057] Example:

[0058] like Figure 1-23As shown, a secondary deployment mechanism and method for a coaxial dual-rotor UAV is disclosed. The phase arm of the UAV body 5 is provided with an upper rotor primary deployment mechanism and a lower rotor secondary deployment mechanism. The upper rotor primary deployment mechanism includes a propeller clamp connected to the phase arm of the UAV body 5 and an upper rotor 14 connected to the propeller clamp. A torsion spring is provided on the connecting screw between the phase arm of the UAV body 5 and the propeller clamp. When the upper rotor 14 is folded and stored in the launch tube, the upper rotor 14 compresses its torsion spring. When the UAV is launched out of the tube, as the UAV leaves the launch tube, the upper rotor 14 is no longer constrained by the inner wall of the launch tube. The upper rotor 14 is deployed to a vertical position of about 80° due to the action of the torsion spring. This part is conventional technology and will not be described in detail in this solution.

[0059] The secondary deployment mechanism of the lower rotor includes the lower rotor 1, the secondary elastic mechanism, and the condition-limiting rotor clip 2;

[0060] The condition-limiting propeller clamp 2 includes a limiting propeller clamp body 21, a boss 23, a round bottom groove 24, a secondary deployment limiting part 25, and a rotor lifting limiting part 26. A lower rotor 1 is connected to one side of the limiting propeller clamp body 21. A boss 23 is provided at the lower end of the other side of the limiting propeller clamp body 21; the other end face of the limiting propeller clamp body 21 is an arc-shaped end face 201; the lower end and top end of the other end face of the limiting propeller clamp body 21 are respectively provided with the secondary deployment limiting part 25 and the rotor lifting limiting part 26, and a round bottom groove 24 is provided at the lower end of the secondary deployment limiting part 25 on the other end face of the limiting propeller clamp body 21. The secondary deployment limiting part 25 is an arc-shaped limiting part that protrudes from and extends beyond the other end face of the limiting propeller clamp body 21. The rotor lifting limit part 26 is a cuboid lifting limit part that protrudes from the other end face of the limiting rotor clamp body 21, and the outer end face of the cuboid lifting limit part is inclined upward from the outside to the inside.

[0061] The secondary elastic mechanism includes a support body 6, a contact head through hole 9, and an elastically retractable contact head assembly.

[0062] One side of the support body 6 is rotatably connected to the limiting propeller clamp body 21. A longitudinally penetrating mounting groove 7 is provided on one end of the support body 6, and the mounting groove 7 is interconnected with the contact head through hole 9; a through mounting hole 8 is provided on the support body 6 corresponding to the position of the mounting groove 7, and the front and rear ends are connected; a connecting through hole 22 is provided in the middle of the upper end of the other side of the limiting propeller clamp body 21, and the limiting propeller clamp body 21 is embedded in the mounting groove 7. The mounting through hole 8 and the connecting through hole 22 of the limiting propeller clamp body 21 are interconnected, and a connecting screw 13 is inserted in the two interconnected holes. A nut 4 is externally threaded to one end of the connecting screw 13 that extends out of the support body 6.

[0063] The other end of the support body 6 has a horizontally oriented contact head through hole 9, within which is a resiliently telescopic contact head assembly. The resiliently telescopic contact head assembly includes a plug 10, a spring 11, and a contact head 12. The plug 10, spring 11, and contact head 12 are connected sequentially. The contact head 12 extends through the contact head through hole 9. When the spring 11 is in its natural state, the contact head 12 engages with the round bottom groove 24. The plug 10 is connected to the inner wall of the outer end of the contact head through hole 9 of the support body 6. The plug 10 can also be connected to the phase arm of the UAV body 5. In this case, the plug 10 and spring 11 become part of the phase arm of the UAV body 5, further compressing the external dimensions of this elastic mechanism.

[0064] One side of the limiting propeller clamp body 21 is detachably connected to the lower rotor 1. A rotor mounting groove 27 is longitudinally opened through one end of the limiting propeller clamp body 21, and a rotor mounting through hole 28 with the front and rear ends connected is opened on the limiting propeller clamp body 21 corresponding to the position of the rotor mounting groove 27; the connecting end of the lower rotor 1 is embedded in the rotor mounting groove 27; the rotor mounting hole of the limiting propeller clamp body 21 and the mounting hole of the connecting end of the lower rotor 1 are interconnected, and a bolt 3 is threadedly connected in the interconnected mounting hole and the bolt 3 is fastened with a nut 4.

[0065] A weight-reducing groove 29 is provided on the upper surface of the other side of the supporting main body 6; a weight-reducing groove 29 is also provided on the front surface of the other side of the limiting rotor clamp main body 21. The weight-reducing groove 29 plays a role in reducing weight, making the lower rotor secondary deployment mechanism lighter.

[0066] Because of the simple design of the secondary elastic mechanism and the condition limit propeller clamp 2, the secondary elastic mechanism and the condition limit propeller clamp 2 are easy to manufacture. Therefore, the secondary elastic mechanism and the condition limit propeller clamp 2 of the same specification can be 100% interchangeable.

[0067] Because the secondary elastic mechanism and the conditional limit propeller clamp 2 are small in size and light in weight, and the processing technology is easy to realize, the production cost of the secondary elastic mechanism and the conditional limit propeller clamp 2 is low.

[0068] During assembly: The supporting body 6 of the secondary elastic mechanism is connected to the phase arm of the UAV body 5; the mounting through hole 8 of the secondary elastic mechanism and the connecting through hole 22 of the condition limiting propeller clamp 2 are interconnected (both are smooth holes), and a connecting screw 13 is inserted in the interconnected mounting through hole 8 and the connecting through hole 22. The end of the connecting screw 13 extending out of the supporting body 6 is externally threaded with a nut 4, thereby realizing the rotational connection between the secondary elastic mechanism and the condition limiting propeller clamp 2; the rotor mounting through hole 28 of the condition limiting propeller clamp 2 is interconnected with the mounting hole at the connecting end of the lower rotor 1, and a bolt 3 is threaded in the interconnected mounting hole. The bolt 3 is fastened with a nut 4, thereby realizing the fixed connection between the condition limiting propeller clamp 2 and the lower rotor 1.

[0069] The present invention also provides a method for deploying the secondary deployment mechanism of the rotor of a coaxial dual-rotor unmanned aerial vehicle, comprising the following steps:

[0070] S1: When the UAV is inside the launch tube, both its upper and lower rotors 1 are folded and stored inside the launch tube. The upper rotor 14 of the UAV compresses its torsion spring (the upper rotor 14 only needs the torsion spring to unfold once), while the boss 23 of the condition-limiting propeller clip 2 compresses the contact head 12 of the secondary elastic mechanism, such as... Figure 1 and Figure 6 As shown, the contact head 12 of the secondary elastic mechanism is compressed for the first time, so that both the upper and lower rotors 1 are in a vertical position and stored in the launch tube.

[0071] S2: After the UAV is launched from the launch tube, as the UAV detaches from the launch tube, the rotor is no longer constrained by the inner wall of the launch tube; the upper rotor 14 is deployed to a vertical position of approximately 80° due to the action of the torsion spring; the contact head 12 of the secondary elastic mechanism is pushed open by the spring 11 due to the release of the elastic potential energy of the spring 11. During the pushing process, the contact head 12 pushes the conditional limit propeller clip 2 and the lower rotor 1 to swing upward along the connecting screw 13. When the contact head 12 is pushed open to its maximum, the lower rotor 1 is deployed for the first time at an angle of 45°, and at this time, the outer end of the contact head 12 is exactly engaged with the round bottom groove 24 of the conditional limit propeller clip 2. Figure 2 , Figure 3 as well as Figure 13 As shown, the secondary deployment limiting part 25 of the condition limiting propeller clip 2 restricts and prevents the lower rotor 1 from continuing to deploy to a larger angle, so that the lower rotor 1 is maintained at the first deployment angle of 45°, that is, the contact head 12 of the secondary elastic mechanism realizes the secondary limiting of the lower rotor 1's waving.

[0072] S3: After the UAV starts its motors, both the upper and lower rotors 1 begin to rotate. The rotation of the lower rotor 1 generates a large centrifugal force on the conditional limiting rotor clamp 2 and the lower rotor 1. This centrifugal force causes the conditional limiting rotor clamp 2 and the lower rotor 1 to generate a counterclockwise torque. Under the action of this torque, the conditional limiting rotor clamp 2 and the lower rotor 1 rotate around the connecting screw 13, pushing and compressing the contact head 12 of the secondary elastic mechanism. As the centrifugal force increases, the generated torque also increases. The secondary deployment limiting part 25 of the conditional limiting rotor clamp 2 will push the contact head 12 of the secondary elastic mechanism, compressing the contact head 12 for the second time. Figure 7 As shown; when the torque reaches the threshold, the secondary deployment limiting part 25 of the condition limiting propeller clamp 2 completely pushes open the contact head 12, and the contact head 12 is compressed back to the low position. The secondary deployment limiting part 25 of the condition limiting propeller clamp 2 completely passes over the contact head 12. At this time, the elastic potential energy of the spring 11 is released, the contact head 12 springs open for the second time, and the lower rotor 1 flaps upward to achieve the second deployment of the lower rotor 1. Due to the centrifugal force, the lower rotor 1 deploys to 90°, as shown. Figure 4 and Figure 5 As shown.

[0073] S4: After the lower rotor 1 deploys for the second time, without sufficient external force, the upper surface of the secondary deployment limiting part 25 of the conditional limiting rotor clip 2 cannot cross the contact head 12 of the secondary elastic mechanism in the reverse direction, preventing the lower rotor 1 from flapping clockwise at a large angle. The secondary deployment limiting part 25 of the conditional limiting rotor clip 2 then becomes the lower limit of the rotor flapping angle. Figure 8 As shown; the contact head 12 also performs a three-stage limit function;

[0074] After the lower rotor 1 deploys for the second time, the outer side of the rotor upward limiting part 26 of the conditional limiting rotor clip 2 cannot cross the outer side wall of the UAV body 5, preventing the lower rotor 1 from continuing to flap counterclockwise at a large angle. The rotor upward limiting part of the conditional limiting rotor clip 2 limits the upper limit of the rotor flapping angle, such as... Figure 9 As shown;

[0075] In summary, the retractable head assembly achieves two releases of elastic potential energy, with the contact head 12 being compressed and then released twice, and the lower rotor 1 being limited by the contact head 12 twice. This enables the lower rotor 1 to unfold in one and two segments, thereby increasing the angle difference between the upper and lower rotors 1 after unfolding and reducing the risk of rotor 1 malfunctioning during startup due to airflow disturbance after launch.

[0076] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A secondary rotor deployment mechanism for a coaxial dual-rotor unmanned aerial vehicle (UAV), wherein the phase arm of the UAV body (5) is provided with an upper rotor primary deployment mechanism and a lower rotor secondary deployment mechanism, characterized in that, The lower rotor secondary deployment mechanism includes a lower rotor (1), a secondary elastic mechanism, and a condition-limiting rotor clip (2). The condition-limiting propeller clamp (2) includes a limiting propeller clamp body (21), a boss (23), a round bottom groove (24), a secondary deployment limiting part (25), and a rotor upward limiting part (26); a lower rotor (1) is connected to one side of the limiting propeller clamp body (21); a boss (23) is provided at the lower end of the other side of the limiting propeller clamp body (21); a secondary deployment limiting part (25) and a rotor upward limiting part (26) are respectively provided at the lower end and the top end of the other side end face of the limiting propeller clamp body (21); a round bottom groove (24) is provided at the lower end of the secondary deployment limiting part (25) on the other side end face of the limiting propeller clamp body (21). The secondary elastic mechanism includes a support body (6), a contact head through hole (9), and an elastically retractable contact head assembly; one side of the support body (6) is rotatably connected to a limit propeller clamp body (21); the other side of the support body (6) is provided with a contact head through hole (9) in a transverse direction, and an elastically retractable contact head assembly is provided in the contact head through hole (9); one end of the elastically retractable contact head assembly extends through the contact head through hole (9), and when the elastically retractable contact head assembly is in its natural state, it engages with the round bottom groove (24); the other end of the elastically retractable contact head assembly is connected to the inner wall of the outer end of the contact head through hole (9) or the phase arm of the UAV body (5); The other end face of the limiting paddle clamp body (21) is an arc-shaped end face (201). The secondary unfolding limiting part (25) is an arc-shaped limiting part that protrudes from the other end face of the limiting paddle clamp body (21); The retractable contact head assembly includes a plug (10), a spring (11), and a contact head (12); the plug (10), spring (11), and contact head (12) are connected in sequence, the contact head (12) extends through the contact head through hole (9), when the spring (11) is in its natural state, the contact head (12) engages with the round bottom groove (24), and the plug (10) is connected to the inner wall of the outer end of the contact head through hole (9) of the support body (6) or the phase arm of the UAV body (5).

2. The rotor secondary deployment mechanism of the coaxial dual-rotor UAV according to claim 1, characterized in that, The limiting propeller clamp body (21) is integrally connected or detachably connected to the lower rotor (1) on one side.

3. The secondary rotor deployment mechanism of the coaxial dual-rotor UAV according to claim 2, characterized in that, The limiting propeller clamp body (21) has a rotor mounting groove (27) that runs longitudinally through one end. The limiting propeller clamp body (21) has a rotor mounting through hole (28) that runs through the front and rear ends, corresponding to the rotor mounting groove (27). The connecting end of the lower rotor (1) is embedded in the rotor mounting groove (27). The rotor mounting hole of the limiting propeller clamp body (21) and the mounting hole of the connecting end of the lower rotor (1) are interconnected. The interconnected mounting holes are threaded with bolts (3) and the bolts (3) are fastened with nuts (4).

4. The secondary rotor deployment mechanism of the coaxial dual-rotor UAV according to claim 1, characterized in that, The rotor lifting limit part (26) is a cuboid lifting limit part that protrudes from the other end face of the limiting rotor clamp body (21); the outer end face of the rotor lifting limit part (26) is inclined upward from the outside to the inside.

5. The secondary rotor deployment mechanism of the coaxial dual-rotor UAV according to claim 1, characterized in that, The support body (6) has a longitudinally through-hole (7) on one side end, and the installation groove (7) is connected to the contact head through hole (9). The support body (6) has an installation through hole (8) with the front and rear ends connected, corresponding to the position of the installation groove (7). The upper middle part of the other side of the limiting propeller clamp body (21) has a connecting through hole (22) with the front and rear ends connected. The limiting propeller clamp body (21) is embedded in the installation groove (7). The installation through hole (8) of the limiting propeller clamp body (21) is connected to the connecting through hole (22). A connecting screw (13) is inserted in the two holes. A nut (4) is externally threaded to one end of the connecting screw (13) that extends out of the support body (6).

6. The secondary rotor deployment mechanism of the coaxial dual-rotor UAV according to claim 1, characterized in that, The other side of the upper end face of the support body (6) is provided with a weight reduction groove (29); the other side of the front end face of the limiting paddle clamp body (21) is provided with a weight reduction groove (29).

7. A method for deploying the secondary deployment mechanism of the rotor of a coaxial dual-rotor UAV as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: When the UAV is inside the launch tube, both the upper rotor (14) and the lower rotor (1) are in a vertical position and are folded and stored inside the launch tube; the upper rotor (14) of the UAV compresses the torsion spring on the upper rotor (14) connecting part, and the boss (23) of the lower rotor (1) compresses the contact head (12). S2: After the UAV is launched from the tube, the upper rotor (14) is deployed to 80°~90° due to the torsion spring; the contact head (12) is pushed open by the spring (11) due to the release of the elastic potential energy of the spring (11). During the process of pushing open, the contact head (12) pushes the condition limit propeller clip (2) and the lower rotor (1) to swing upward along the connecting screw (13). When the contact head (12) is pushed open to the maximum, the lower rotor (1) is deployed for the first time with a deployment angle of 45°. The outer end of the contact head (12) is exactly engaged with the round bottom groove (24) of the condition limit propeller clip (2). S3: After the UAV starts the motor, the upper and lower rotors (1) begin to rotate; the rotation of the lower rotor (1) causes the condition limit propeller clamp (2) and the lower rotor (1) to generate centrifugal force, and the centrifugal force causes the condition limit propeller clamp (2) and the lower rotor (1) to generate counterclockwise torque. Under the action of the torque, the condition limit propeller clamp (2) and the lower rotor (1) rotate around the connecting screw (13), pushing and compressing the contact head (12) for the second time; when the torque reaches the threshold, the secondary deployment limit part (25) completely pushes open the contact head (12), and the contact head (12) is compressed back to the low position. When the secondary deployment limit part (25) completely passes the contact head (12), the elastic potential energy of the spring (11) is released, the contact head (12) springs open for the second time, and the lower rotor (1) swings upward to realize the second deployment of the lower rotor (1). Due to the action of centrifugal force, the lower rotor (1) is deployed to 90°. S4: After the lower rotor (1) is deployed for the second time, without sufficient external force, the upper surface of the secondary deployment limiting part (25) cannot cross the contact head (12) of the secondary elastic mechanism in the opposite direction. The secondary deployment limiting part (25) is the lower limit of the rotor flapping angle. After the lower rotor (1) is deployed for the second time, the outer side of the rotor upward limiting part (26) cannot cross the outer wall of the phase arm of the UAV body (5), which restricts the lower rotor (1) from continuing to flap counterclockwise at a large angle. The rotor upward limiting part is the upper limit of the rotor flapping angle.

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