A multi-rotor drone

Abstract

The application discloses a multi-rotor unmanned aerial vehicle, which comprises a frame assembly, a plurality of rotor assemblies distributed in a circular ring shape outside the frame assembly, and a fixing rod assembly connected between the frame assembly and the rotor assemblies, wherein the rotor assemblies are slidably installed on the fixing rod assembly, and a movable rod assembly is rotatably connected to one end of the fixing rod assembly away from the frame assembly, and a connecting assembly is arranged at the other end of the movable rod assembly. In the application, the rotor assemblies are slidably displaced, and when the multi-rotor unmanned aerial vehicle device is ready to be spliced, the rotor assemblies can be slid to the fixing rod body area and the connecting assemblies are synchronously unfolded, so that the collision of the rotor assemblies during splicing is avoided.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) technology, specifically a multi-rotor UAV. Background Technology

[0002] The rapid development of drone technology has made the interconnection of multiple drones a new research field; the significance of this interconnection lies in its ability to achieve more efficient task execution, more powerful data processing capabilities, and more intelligent collaborative work.

[0003] First, interconnecting multiple drones can improve mission efficiency. In search and rescue missions, one drone can be responsible for searching while another can be responsible for transporting supplies. By interconnecting, drones can quickly exchange information and location data, thus finding targets faster.

[0004] Secondly, interconnection between multiple drones can provide more powerful data processing capabilities. Drones are usually equipped with a variety of sensors that can collect a large amount of data. Through interconnection, a stable connection makes it easier for multiple drones to share data, thereby obtaining more comprehensive information. In addition, multiple drones can also perform collaborative analysis, thereby identifying targets more quickly.

[0005] Finally, interconnection between multiple drones enables more intelligent collaborative work. By connecting with each other, drones can share their status and location information, thereby better coordinating their actions; for example, in agriculture, multiple drones can work together to cover a larger area more quickly.

[0006] In summary, the interconnection of multiple drones is of great significance; it can improve mission execution efficiency, provide more powerful data processing capabilities, and enable more intelligent collaborative work.

[0007] The prior art patent document, "A Combined Multi-rotor UAV and Its Control Method" (publication number CN112977793B), describes a combined multi-rotor UAV that has the effect of improving payload capacity.

[0008] The prior art patent document (publication number CN113104213B) describes a modular deformable drone structure. After the drone is partially damaged, the module can be quickly replaced to continue working. The structure is deformable, suitable for diverse mission requirements, and has the effects of being easy to carry, quick to deploy, and versatile in combination.

[0009] However, the combination methods of multiple drones described in the above inventions are difficult to achieve the effect of controlling and combining them in flight attitude. At the same time, since the drone is more stable the farther the wings are from the fuselage, the first part of the drones to come into contact with each other when multiple drones are combined in the air is the wing part, which needs to be avoided from contact. While placing the wings in the middle area of ​​the drone's stick avoids the collision between the wings, it will affect the utilization rate of the fuselage during normal use. In addition, the stick extending from the outside of the wings will increase the safety distance and may cause the drone to be unstable during flight. Summary of the Invention

[0010] The purpose of this invention is to provide a multi-rotor drone in order to solve the technical problem of mutual interference between wings when multiple drones are combined in the air, while avoiding the low utilization rate of the fuselage when the wings interfere.

[0011] The technical solution adopted in this invention is as follows:

[0012] A multi-rotor unmanned aerial vehicle (UAV) includes a frame assembly, a plurality of rotor assemblies arranged in a ring around the outside of the frame assembly, and a fixed rod assembly connecting the frame assembly and the rotor assemblies. The rotor assemblies are slidably mounted on the fixed rod assembly. A movable rod assembly is rotatably connected to one end of the fixed rod assembly away from the frame assembly, and a connecting assembly is provided at the other end of the movable rod assembly.

[0013] The rack assembly includes a frame and support legs mounted at the bottom of the frame;

[0014] The fixing rod assembly includes a fixing rod body connected to the frame assembly;

[0015] The movable rod assembly includes a movable rod body that communicates with a fixed rod body. The fixed rod body and the movable rod body are interconnected to form a pipe cavity. The pipe cavity is provided with a slidable first sliding cylinder and a second sliding cylinder. A universal joint assembly connects the first sliding cylinder and the second sliding cylinder. A sleeve extends outward from the end face contour of the first sliding cylinder away from the second sliding cylinder. An electric telescopic rod is fixed inside the fixed rod body, and the output end of the electric telescopic rod passes through the inner cavity of the sleeve and is fixed to the first sliding cylinder.

[0016] The universal joint assembly includes a spherical shaft connected to a first sliding cylinder and a spherical bushing connected to a second sliding cylinder, wherein the spherical shaft and the spherical bushing are spherically rotatably connected.

[0017] The rotor assembly includes a rotor motor, rotating fan blades fixed at the output end of the rotor motor, and a fixing clamp mounted on the outside of the rotor motor. The fixing clamp is slidably connected to both the fixed rod and the movable rod. A through connecting rod fixed to the rotor motor is provided on the first sliding cylinder.

[0018] The fixed rod has a first through guide groove that slides with the through connecting rod, the movable rod has a second through guide groove that slides with the through connecting rod, the second sliding cylinder has an upper slider that slides with the second through guide groove, the first sliding cylinder has a lower slider fixed at the symmetrical end away from the through connecting rod on the arc-shaped side, and the fixed rod has an inner groove that slides with the lower slider.

[0019] The fixing clamp has a protrusion extending towards the inner wall of the pipe, the outer wall of the fixing rod has a first outer groove along the diameter direction to cooperate with the sliding of the protrusion, and the outer wall of the movable rod has a second outer groove along the diameter direction to cooperate with the sliding of the protrusion.

[0020] The connecting assembly includes a connecting frame consisting of four straight rod segments connected in a rectangular frame shape, a hinged connecting rod rotatably connected to one side of the straight rod segment of the connecting frame, a connecting plate fixedly connected to the connecting frame, and multiple plug-in frames fixed on the side of the connecting plate away from the connecting frame. Another straight rod segment on the connecting frame that is parallel to the rotatable connection point of the hinged connecting rod is set as an extension rod.

[0021] The frame has a retraction assembly at its bottom center. The retraction assembly includes a stepper motor fixed to the frame, a winding roller fixed to the output end of the stepper motor, and multiple traction lines wound on the winding roller. The free ends of the multiple traction lines away from the winding roller are respectively wound and fixed to extension rods in multiple connecting assemblies.

[0022] Among them, a through-rotating shaft is also connected between the two straight rod sections connected to the extension rod in the connecting frame. The through-rotating shaft is rotatably connected to the end of the movable rod away from the fixed rod. The second sliding cylinder is provided with a through-shaft extending to the outside of the movable rod. The end of the hinged connecting rod away from the connecting frame is rotatably connected to the through-shaft.

[0023] The plurality of plug-in frames are arranged in a straight line at equal intervals, and plug-in gaps are provided between the plurality of plug-in frames to accommodate the plug-in frames. Adsorption magnetic chains are provided at the edges of the plug-in frames near the plug-in gaps, and the inner cavity of the plug-in frames is provided with accommodating cavities to accommodate the adsorption magnetic chains.

[0024] The adsorption magnetic chain includes a through-line distributed in a ring around the opening of the accommodating cavity, and multiple small and large magnetic beads passing through the through-line. The multiple small and large magnetic beads are distributed in pairs on the through-line. The large magnetic beads are disposed inside the accommodating cavity, and the small magnetic beads are disposed at the opening of the accommodating cavity. The opening of the accommodating cavity is also provided with a baffle groove. The opening spacing of the baffle groove is greater than the radius of the small magnetic beads and smaller than the radius of the large magnetic beads.

[0025] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0026] 1. In this invention, a slidable rotor assembly is used. Due to the multi-segment connection structure between the rotor assembly and the frame assembly, which includes a fixed rod and a movable rod, the connection structure between the rotor assembly and the frame assembly is fully extended to achieve maximum utilization when the multi-rotor UAV device is not assembled. When the multi-rotor UAV device is ready to be assembled, the rotor assembly can slide to the fixed rod area and simultaneously unfold the connection assembly to avoid collisions caused by the rotor assembly during assembly.

[0027] 2. In this invention, a movable rod assembly with rotatable and telescopic length is used. When the sleeve is located at the connection between the movable rod and the fixed rod, it can maintain the axial fixation between the movable rod and the fixed rod. When the rotating part of the universal joint assembly is located at the connection between the movable rod and the fixed rod, the movable rod can rotate in the vertical direction around the plane of the connection between the movable rod and the fixed rod, thereby achieving the effect of controlling the rotation of the movable rod and unfolding the connecting assembly. Attached Figure Description

[0028] Figure 1 This is a simplified schematic diagram of the main structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0030] Figure 3 This is a partial structural diagram of a single fixed rod assembly in the present invention. Figure 1 ;

[0031] Figure 4 This is a schematic diagram of the overall cross-sectional structure of the present invention;

[0032] Figure 5 For the present invention Figure 4 Enlarged structural diagram at point A in the middle;

[0033] Figure 6 This is a schematic diagram of the partial truncated structure at a single fixed rod assembly in this invention;

[0034] Figure 7This is a partial structural diagram of a single fixed rod assembly in the present invention. Figure 2 ;

[0035] Figure 8 This is a vertical cross-sectional view of a portion of the structure at a single fixed rod assembly in this invention;

[0036] Figure 9 For the present invention Figure 8 Enlarged structural diagram at point B;

[0037] Figure 10 This is a cross-sectional view of a portion of the structure at a single fixed rod assembly in this invention.

[0038] Figure 11 For the present invention Figure 10 Enlarged structural diagram at point C;

[0039] Figure 12 For the present invention Figure 11 Enlarged structural diagram at point D;

[0040] Marked in the image:

[0041] 1. Rack assembly; 11. Frame; 12. Support legs;

[0042] 2. Fixing rod assembly; 21. Fixing rod body; 22. First outer groove; 23. First through guide groove; 24. Inner groove;

[0043] 3. Rotor assembly; 31. Rotor motor; 32. Rotating fan blade; 33. First sliding cylinder; 331. Lower slider; 332. Through connecting rod; 34. Electric telescopic rod; 35. Sleeve; 36. Spherical bushing; 37. Spherical shaft; 38. Second sliding cylinder; 381. Upper slider; 382. Through shaft; 39. Fixture;

[0044] 4. Movable rod assembly; 41. Movable rod body; 42. Second through guide groove; 43. Second outer groove; 44. Hinged connecting rod; 45. Through pivot; 451. Extension rod; 46. Connecting frame;

[0045] 5. Connecting components; 51. Connecting plate; 52. Insertion frame; 53. Accommodating cavity; 54. Retaining slot; 55. Small magnetic bead; 56. Large magnetic bead; 57. Through wire; 58. Insertion gap;

[0046] 6. Take-up and take-down assembly; 61. Stepper motor; 62. Winding roller; 63. Traction line. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] Example 1, refer to Figures 1-12 A multi-rotor unmanned aerial vehicle includes a frame assembly 1, a plurality of rotor assemblies 3 arranged in a ring on the outside of the frame assembly 1, and a fixed rod assembly 2 connecting the frame assembly 1 and the rotor assemblies 3. The rotor assemblies 3 are slidably mounted on the fixed rod assembly 2. A movable rod assembly 4 is rotatably connected to one end of the fixed rod assembly 2 away from the frame assembly 1, and a connecting assembly 5 is provided at the other end of the movable rod assembly 4.

[0049] The frame assembly 1 is mounted with the movable rod assembly 4 and the rotor assembly 3 via the fixed rod assembly 2. The rotor assembly 3 is slidably disposed between the movable rod assembly 4 and the fixed rod assembly 2. When the movable rod assembly 4 and the fixed rod assembly 2 are on the same straight line, the rotor assembly 3 can slide back and forth between the movable rod assembly 4 and the fixed rod assembly 2. At this time, the connection between the movable rod assembly 4 and the fixed rod assembly 2 is limited and fixed.

[0050] When the rotor assembly 3 is completely moved to the area of ​​the fixed rod assembly 2, the limiting effect at the connection between the movable rod assembly 4 and the fixed rod assembly 2 is canceled. The connection between the movable rod assembly 4 and the fixed rod assembly 2 can be rotated into a zigzag state by rotating the movable rod assembly 4 and the fixed rod assembly 2. At the same time, the connecting component 5 at one end of the movable rod assembly 4 unfolds to enable aerial docking between multiple multi-rotor UAV devices through the connecting component 5, until an interconnected platform is formed.

[0051] The rack assembly 1 includes a frame 11 and support legs 12 mounted on the bottom of the frame 11;

[0052] Among them, the support leg 12 has a "T" shaped structure. The two ends of the support leg 12 near the intersection are used to touch the ground, and the other end is used to be fixedly installed with the frame 11.

[0053] The fixing rod assembly 2 includes a fixing rod body 21 that is connected to the frame assembly 1;

[0054] The movable rod assembly 4 includes a movable rod 41 connected to the fixed rod 21. The inner cavities of the fixed rod 21 and the movable rod 41 are interconnected to form a pipe cavity. The pipe cavity is provided with a slidable first sliding cylinder 33 and a second sliding cylinder 38. A universal joint assembly is connected between the first sliding cylinder 33 and the second sliding cylinder 38. A sleeve 35 extends outward from the end face contour of the first sliding cylinder 33 away from the second sliding cylinder 38. An electric telescopic rod 34 is fixed inside the fixed rod 21, and the output end of the electric telescopic rod 34 passes through the inner cavity of the sleeve 35 and is fixed to the first sliding cylinder 33.

[0055] When the electric telescopic rod 34 drives the first sliding cylinder 33 to be located in the inner cavity of the movable rod 41, the connection between the movable rod 41 and the fixed rod 21 will be supported by the sleeve 35 on one side of the first sliding cylinder 33. At this time, the movable rod 41 and the fixed rod 21 are aligned on the central axis, so that the movable rod 41 and the fixed rod 21 simultaneously serve as connecting parts between the rotor assembly 3 and the frame assembly 1, further increasing the distance between the rotor assembly 3 and the frame assembly 1, thereby increasing the overall stability of the multi-rotor UAV device.

[0056] When the electric telescopic rod 34 drives the first sliding cylinder 33 to be located in the inner cavity of the fixed rod 21, and the connection between the movable rod 41 and the fixed rod 21 coincides with the pivot of the universal joint assembly, the movable rod 41 and the fixed rod 21 are in a rotatable state. That is, the central axis of the connection surface between the movable rod 41 and the fixed rod 21 can be used as the rotation axis for the movable rod 41 to rotate around the fixed rod 21, so that the movable rod 41 can drive the connecting component 5 to unfold, so that multiple multi-rotor UAV devices can be spliced ​​together through the unfolded connecting component 5. At the same time, when the devices are not docked, the connecting component 5 is in a retracted state, and the rotor assembly 3 is located at the farthest end from the frame assembly 1 in the overall device, so that the rotor assembly 3 provides the best stability effect for the overall device.

[0057] The fixed rod assembly 2 is set into six groups, and the six groups of fixed rod assemblies 2 are distributed in a ring at equal intervals around the frame assembly 1. The connecting components 5 connected to the outside of the fixed rod assembly 2 and the movable rod assembly 4 are connected to each other to form a regular hexagonal structure. Multiple multi-rotor UAV devices are fixed to each other through the connecting components 5 located at the six ends of the regular hexagonal structure, thereby forming an integrated flight platform for multiple multi-rotor UAV devices.

[0058] The universal joint assembly includes a spherical shaft 37 connected to the first sliding cylinder 33 and a spherical bushing 36 connected to the second sliding cylinder 38, wherein the spherical shaft 37 and the spherical bushing 36 are spherically rotatably connected.

[0059] The connection between the fixed rod 21 and the movable rod 41 is a tubular structure that overlaps with each other at an oblique angle. When the spherical shaft 37 and spherical bushing 36 in the universal joint assembly move to the connection between the fixed rod 21 and the movable rod 41, the fixed rod 21 and the movable rod 41 can rotate through the universal joint assembly. After the movable rod 41 rotates 180° around the vertical central axis of the connection surface with the fixed rod 21, the connection between the fixed rod 21 and the movable rod 41 can still remain tightly fitted. At the same time, the connecting component 5, which was originally at the bottom of the movable rod assembly 4, is unfolded and used to connect with the connecting components 5 of other multi-rotor UAV devices.

[0060] The rotor assembly 3 includes a rotor motor 31, a rotating fan blade 32 fixed at the output end of the rotor motor 31, and a fixing clamp 39 installed on the outside of the rotor motor 31. The fixing clamp 39 is slidably connected to the fixing rod 21 and the movable rod 41. A through connecting rod 332 fixed to the rotor motor 31 is provided on the first sliding cylinder 33.

[0061] The rotor motor 31 in the rotor assembly 3 is slidably mounted on the outside of the fixed rod 21 and the movable rod 41 via the fixing clamp 39. At the same time, the first sliding cylinder 33 is connected to the rotor motor 31 via the through connecting rod 332. This allows the first sliding cylinder 33 to slide between the fixed rod 21 and the movable rod 41 while sliding inside the pipe, thereby adjusting the position of the rotor assembly 3. This prevents the rotor assemblies 3 from intersecting when multiple multi-rotor drone devices are connected, and further avoids collisions between the rotor assemblies 3.

[0062] The fixed rod 21 is provided with a first through guide groove 23 that slides with the through connecting rod 332, the movable rod 41 is provided with a second through guide groove 42 that slides with the through connecting rod 332, the second sliding cylinder 38 is fixed with an upper slider 381 that slides with the second through guide groove 42, the arc-shaped side of the first sliding cylinder 33 is fixed with a lower slider 331 at the symmetrical end away from the through connecting rod 332, and the fixed rod 21 is provided with an inner groove 24 that slides with the lower slider 331.

[0063] The inner wall of the movable rod 41 is also provided with an inner groove structure that cooperates with the sliding block 331 to slide, so that when the fixed rod 21 slides in the movable rod 41, axial rotation between the movable rod 41 and the fixed rod 21 is avoided.

[0064] The fixed clamp 39 has a protrusion extending towards the inner wall of the pipe. The outer wall of the fixed rod 21 has a first outer groove 22 that slides along the diameter direction to accommodate the protrusion. The outer wall of the movable rod 41 has a second outer groove 43 that slides along the diameter direction to accommodate the protrusion.

[0065] The first through guide groove 23 and the second through guide groove 42 are provided to ensure that the first sliding cylinder 33 does not have axial displacement or shaking during the sliding process between the fixed rod 21 and the inner cavity of the movable rod 41, so that the rotor assembly 3 above the first sliding cylinder 33 maintains a stable posture.

[0066] The first outer groove 22 and the second outer groove 43 are staggered with the first through guide groove 23 and the second through guide groove 42 to avoid overlapping in the same area of ​​the fixed rod 21 and the movable rod 41.

[0067] Furthermore, the protrusion of the fixing clamp 39, as well as the first outer groove 22 and the second outer groove 43, enable the rotor assembly 3 to form an axial engagement with the connection area of ​​the fixed rod 21 and the movable rod 41, further preventing the rotor assembly 3 from axially shifting during the sliding process.

[0068] The connecting assembly 5 includes a connecting frame 46 consisting of four straight rod segments connected in a rectangular frame shape, a hinged connecting rod 44 rotatably connected to one side of the straight rod segment of the connecting frame 46, a connecting plate 51 fixedly connected to the connecting frame 46, and multiple plug-in frames 52 fixed on the side of the connecting plate 51 away from the connecting frame 46. Another straight rod segment on the connecting frame 46 parallel to the rotatable connection point of the hinged connecting rod 44 is configured as an extension rod 451.

[0069] A through-rotating shaft 45 is also connected between two straight rod segments connected to the extension rod 451 inside the connecting frame 46. The through-rotating shaft 45 is rotatably connected to the end of the movable rod 41 away from the fixed rod 21. The second sliding cylinder 38 is provided with a through-rotating shaft 382 extending to the outside of the movable rod 41. The end of the hinged connecting rod 44 away from the connecting frame 46 is rotatably connected to the through-rotating shaft 382.

[0070] When the second sliding cylinder 38 is located inside the movable rod 41 near the end of the fixed rod 21, the second sliding cylinder 38 drives the through shaft 382 to unfold the hinged connecting rod 44 and the connecting frame 46 from the folded state, so that the connecting plate 51 is flipped to be perpendicular to the horizontal plane, so that the connecting assembly 5 can be used for connection between multiple multi-rotor UAV devices after unfolding.

[0071] When the second sliding cylinder 38 is located inside the movable rod 41 at the end away from the fixed rod 21, the second sliding cylinder 38 drives the through shaft 382, ​​causing the hinged connecting rod 44 and the connecting frame 46 to overlap and fold, thereby making the connecting frame 46 fit against the outer wall of the movable rod 41, reducing the wind resistance generated when this part of the device is not in use.

[0072] A retractable assembly 6 is provided at the center of the bottom of the frame 11. The retractable assembly 6 includes a stepper motor 61 fixed to the frame 11, a winding roller 62 fixed to the output end of the stepper motor 61, and multiple traction lines 63 wound on the winding roller 62. The free ends of the multiple traction lines 63 away from the winding roller 62 are respectively wound and fixed to the extension rods 451 in the multiple connecting assemblies 5.

[0073] The stepper motor 61 can drive the winding roller 62 to rotate, so that the traction line 63 wrapped around the outside of the winding roller 62 is tightened and pulled to the extension rod 451, so that the movable rod 41 changes from a state that coincides with the central axis of the fixed rod 21 to a state that rotates 180° around the rotation axis of the connection, thereby causing the connection component 5 to unfold.

[0074] Example 2, refer to Figures 1-12 Multiple plug-in frames 52 are arranged in a straight line at equal intervals. A plug-in gap 58 is provided between the multiple plug-in frames 52 to accommodate the plug-in frames 52. Adsorption magnetic chains are provided at the edges of the plug-in frames 52 near the plug-in gap 58. An accommodating cavity 53 for accommodating the adsorption magnetic chains is opened in the inner cavity of the plug-in frame 52.

[0075] When multiple multi-rotor UAV devices are connected to each other, a complete fixed connection is formed by the insertion gap 58 between two connecting components 5 and the insertion frame 52. Specifically, the insertion frame 52 is a closed rectangular frame structure formed by four vertical plates that are simultaneously perpendicular to the horizontal plane and connected to each other. The four vertical plates are respectively set as the first, second, third and fourth surfaces, and the first and fourth surfaces are connected. The second and fourth surfaces in the insertion frame 52 are both set as isosceles trapezoidal plate structures, and the first and third surfaces are both set as rectangular plate structures. The width of the first surface is greater than the width of the third surface, so as to facilitate the insertion between multiple insertion frames 52 and the insertion gap 58.

[0076] The adsorption magnetic chain includes a through-line 57 that is distributed in a ring around the opening of the accommodating cavity 53, and multiple small magnetic beads 55 and large magnetic beads 56 passing through the through-line 57. The multiple small magnetic beads 55 and large magnetic beads 56 are distributed in pairs on the through-line 57. The large magnetic beads 56 are located inside the accommodating cavity 53, and the small magnetic beads 55 are located at the opening of the accommodating cavity 53. A baffle 54 is also provided at the opening of the accommodating cavity 53. The opening spacing of the baffle 54 is greater than the radius of the small magnetic beads 55 and smaller than the radius of the large magnetic beads 56.

[0077] When multiple plug-in frames 52 are fully connected to each other to form a flush plug-in effect, the large magnetic beads 56 and small magnetic beads 55 on different plug-in frames 52 are close to each other and attract each other, thereby fixing the plug-in frames 52 after they are flush. When the plug-in frames 52 are misaligned, the large magnetic beads 56 and small magnetic beads 55 on the entire through line 57 are mismatched and it is difficult to form a misaligned fixing effect when attracting, thus avoiding locking when the plug-in is incorrect.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-rotor unmanned aerial vehicle (UAV), comprising a frame assembly (1), a plurality of rotor assemblies (3) arranged in a ring around the outside of the frame assembly (1), and a fixed rod assembly (2) connecting the frame assembly (1) and the rotor assemblies (3), characterized in that: The rotor assembly (3) is slidably mounted on the fixed rod assembly (2). The fixed rod assembly (2) is rotatably connected to a movable rod assembly (4) at one end away from the frame assembly (1). The other end of the movable rod assembly (4) is provided with a connecting assembly (5). The rack assembly (1) includes a frame (11) and support legs (12) mounted on the bottom of the frame (11). The fixed rod assembly (2) includes a fixed rod body (21) connected to the frame assembly (1); The movable rod assembly (4) includes a movable rod (41) connected to a fixed rod (21). The inner cavities of the fixed rod (21) and the movable rod (41) are interconnected to form a pipe cavity. The pipe cavity is provided with a slidable first sliding cylinder (33) and a second sliding cylinder (38). A universal joint assembly is connected between the first sliding cylinder (33) and the second sliding cylinder (38). A sleeve (35) extends outward from the end face contour of the first sliding cylinder (33) away from the second sliding cylinder (38). An electric telescopic rod (34) is fixed inside the fixed rod (21), and the output end of the electric telescopic rod (34) passes through the inner cavity of the sleeve (35) and is fixed to the first sliding cylinder (33). The rotor assembly (3) includes a rotor motor (31), a rotating fan blade (32) fixed at the output end of the rotor motor (31), and a fixing clamp (39) installed on the outside of the rotor motor (31). The fixing clamp (39) is slidably connected to the fixing rod (21) and the movable rod (41). The first sliding cylinder (33) is provided with a through connecting rod (332) fixed to the rotor motor (31). The connecting assembly (5) includes a connecting frame (46) consisting of four straight rod segments connected in a rectangular frame shape, a hinged connecting rod (44) rotatably connected to one side of the straight rod segment of the connecting frame (46), a connecting plate (51) fixedly connected to the connecting frame (46), and multiple plug-in frames (52) fixed on the side of the connecting plate (51) away from the connecting frame (46). Another straight rod segment on the connecting frame (46) parallel to the rotatable connection point of the hinged connecting rod (44) is set as an extension rod (451).

2. A multi-rotor unmanned aerial vehicle as described in claim 1, characterized in that: The universal joint assembly includes a spherical shaft (37) connected to the first sliding cylinder (33) and a spherical bushing (36) connected to the second sliding cylinder (38), wherein the spherical shaft (37) and the spherical bushing (36) are spherically rotatably connected.

3. A multi-rotor unmanned aerial vehicle as described in claim 2, characterized in that: The fixed rod (21) is provided with a first through guide groove (23) that slides with the through connecting rod (332), the movable rod (41) is provided with a second through guide groove (42) that slides with the through connecting rod (332), the second sliding cylinder (38) is fixed with an upper slider (381) that slides with the second through guide groove (42), the arc-shaped side of the first sliding cylinder (33) is fixed with a lower slider (331) at the symmetrical end away from the through connecting rod (332), and the fixed rod (21) is provided with an inner groove (24) that slides with the lower slider (331).

4. A multi-rotor unmanned aerial vehicle as described in claim 3, characterized in that: The fixing clamp (39) has a protrusion extending to one side of the inner wall of the pipe. The outer wall of the fixing rod (21) is provided with a first outer groove (22) that slides with the protrusion along the diameter direction. The outer wall of the movable rod (41) is provided with a second outer groove (43) that slides with the protrusion along the diameter direction.

5. A multi-rotor unmanned aerial vehicle as described in claim 1, characterized in that: A take-up and take-down assembly (6) is provided at the center of the bottom of the frame (11). The take-up and take-down assembly (6) includes a stepper motor (61) fixed to the frame (11), a winding roller (62) fixed to the output end of the stepper motor (61), and multiple traction lines (63) wound on the winding roller (62). The free ends of the multiple traction lines (63) away from the winding roller (62) are respectively wound and fixed to the extension rods (451) in the multiple connecting assemblies (5).

6. A multi-rotor unmanned aerial vehicle as described in claim 5, characterized in that: A through-rotating shaft (45) is also connected between the two straight rod segments connected to the extension rod (451) in the connecting frame (46). The through-rotating shaft (45) is rotatably connected to the end of the movable rod (41) away from the fixed rod (21). The second sliding cylinder (38) is provided with a through-rotating shaft (382) extending to the outside of the movable rod (41). The end of the hinged connecting rod (44) away from the connecting frame (46) is rotatably connected to the through-rotating shaft (382).

7. A multi-rotor unmanned aerial vehicle as described in claim 6, characterized in that: Multiple plug-in frames (52) are arranged in a straight line at equal intervals. A plug-in gap (58) is provided between the multiple plug-in frames (52) to accommodate the plug-in frames (52) for plugging. An adsorption magnetic chain is provided at the edge of each plug-in frame (52) near the plug-in gap (58). A receiving cavity (53) is opened in the inner cavity of each plug-in frame (52) to accommodate the adsorption magnetic chain.

8. A multi-rotor unmanned aerial vehicle as described in claim 7, characterized in that: The adsorption magnetic chain includes a through-line (57) that is distributed in a ring around the opening of the accommodating cavity (53), and multiple small magnetic beads (55) and large magnetic beads (56) passing through the through-line (57). The multiple small magnetic beads (55) and large magnetic beads (56) are distributed in pairs on the through-line (57). The large magnetic beads (56) are located inside the accommodating cavity (53), and the small magnetic beads (55) are located at the opening of the accommodating cavity (53). The opening of the accommodating cavity (53) is also provided with a baffle (54). The opening spacing of the baffle (54) is greater than the radius of the small magnetic beads (55) and smaller than the radius of the large magnetic beads (56).

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