阅读说明：本技术 无人机复飞装置及无人机 (Unmanned aerial vehicle flies device and unmanned aerial vehicle again ) 是由 岳焕印 廖小罕 叶虎平 于 2020-06-19 设计创作，主要内容包括：本发明涉及一种无人机复飞装置及无人机,当无人机在飞行时或/和当无人机在准备起飞返程时,若其旋翼发生损坏,则通过伸缩装置控制设置在连接件内的电机沿设置在连接件内的圆柱形的滑槽向下移动,在电机沿滑槽向下移动时,通过设置在折叠桨叶上的支撑件与旋翼相抵,使电机的转轴与旋翼完全分离,并在电机沿滑槽向下移动时,触发一端设置在滑槽内且该端在电机的向下移动的行程内的触发部件,使连接在触发部件的另一端且折叠在连接件外侧的折叠桨叶展开并连接在转轴上,此时,折叠桨叶随转轴同步旋转,继续向无人机提供升力,以保证无人机能正常飞行或/和正常起飞,减少用户损失,且不会危及他人的生命安全。(The invention relates to an unmanned aerial vehicle re-flying device and an unmanned aerial vehicle, when the unmanned aerial vehicle flies or/and when the unmanned aerial vehicle is ready to take off and return, if a rotor wing of the unmanned aerial vehicle is damaged, a motor arranged in a connecting piece is controlled to move downwards along a cylindrical sliding groove arranged in the connecting piece through a telescopic device, when the motor moves downwards along the sliding groove, a support piece arranged on a folding paddle blade is abutted against the rotor wing, a rotating shaft of the motor is completely separated from the rotor wing, when the motor moves downwards along the sliding groove, a trigger component with one end arranged in the sliding groove and the other end in the downward movement stroke of the motor is triggered, the folding paddle blade connected to the other end of the trigger component and folded outside the connecting piece is unfolded and connected on the rotating shaft, at the moment, the folding paddle blade rotates synchronously along with the rotating shaft, the lift force is continuously provided for the unmanned aerial vehicle, so as to ensure that the unmanned, the loss of the user is reduced, and the life safety of other people is not endangered.)

1. The unmanned aerial vehicle fly-back device is characterized by comprising a connecting piece (1), a motor (2), a rotor wing (3), a telescopic device (4), a trigger part (5) and at least two folding blades;

the bottom end of the connecting piece (1) is connected with an unmanned aerial vehicle body, a cylindrical sliding groove (6) is formed in the connecting piece (1), the motor (2) is connected in the sliding groove (6) in a sliding mode, a rotating shaft (7) of the motor (2) penetrates out of the top end of the connecting piece (1) and is connected with the rotor wing (3), the telescopic device (4) is arranged in the sliding groove (6) and located below the motor (2), and the telescopic device (4) is used for controlling the motor (2) to move downwards along the sliding groove (6) when the rotor wing (3) is damaged;

the folding blade is also provided with a supporting piece (8) which is used for abutting against the rotor wing (3) when the motor (2) moves downwards along the sliding chute (6) so as to completely separate the rotating shaft (7) from the rotor wing (3);

one end of the trigger component (5) is arranged in the sliding groove (6) and is in the downward moving stroke of the motor (2), and the trigger component (5) is used for: when triggered, the folding paddle which is connected to the other end of the trigger part (5) and is folded outside the connecting piece (1) is unfolded and connected to the rotating shaft (7).

2. Unmanned aerial vehicle missed approach device of claim 1, characterized in that, the folding paddle includes folding portion (9) and fixed part (10), set up the support piece (8) on the fixed part (10), be equipped with 90 degrees auto-lock articulated elements (11) between the folding portion (9) and the fixed part (10);

an elastic sheet (12) is further arranged between the folding part (9) and the connecting piece (1), and the elastic sheet (12) is abutted against the folding part (9);

the other end of the trigger component (5) is fixedly connected with the folding part (9) and compresses the elastic sheet (12), so that the folding part (9) is folded at the outer side of the connecting piece (1).

3. The unmanned aerial vehicle missed approach device of claim 2, characterized in that, the pivot (7) is provided with a boss (13) with a circular cross section, the boss (13) is provided with grooves (14), and the number of the grooves (14) is the same as the number of the fixing parts (10);

the other end of the fixing part (10) is provided with an arc-shaped sheet (15) matched with the boss (13), convex strips (16) matched with the grooves (14) are arranged in the arc-shaped sheet (15), and the convex strips (16) correspond to the grooves (14) one by one;

the groove (14) and the protruding strip (16) are used for clamping when the motor (2) moves downwards along the sliding groove (6).

4. An unmanned aerial vehicle missed approach device according to claim 2 or 3, characterized in that, still be equipped with on connecting piece (1) with pivot (7) concentric bearing (17), be equipped with connecting rod (18) between bearing (17) and fixed part (10).

5. Unmanned aerial vehicle missed approach device of claim 4, characterized by further comprising a clamping member (19) disposed between the motor (2) and the chute (6), the clamping member (19) being configured to: the relative position between the motor (2) and the chute (6) is fixed before the motor (2) moves down along the chute (6) and is destroyed when the motor (2) moves down along the chute (6).

6. An unmanned aerial vehicle fly-back device according to any one of claims 1 to 3 or 5, further comprising a controller, wherein the controller is used for acquiring the lift force of each rotor (3) of the unmanned aerial vehicle, comparing the lift force of each rotor (3) with a preset lift force one by one, and determining whether the rotor (3) is damaged or not according to the comparison result; and determining whether to send an instruction for controlling the motor (2) to move downwards along the sliding chute (6) to the telescopic device (4) or not according to the damage result.

7. Unmanned aerial vehicle missed approach device of any one of claims 1 to 3 or 5, characterized in that, the telescoping device (4) is an electromagnet device or a hydraulic telescoping rod.

8. An unmanned aerial vehicle, characterized in that the unmanned aerial vehicle missed approach device of any one of claims 1 to 7 is adopted.

Technical Field

The invention relates to the technical field of unmanned aerial vehicles, in particular to an unmanned aerial vehicle missed-flight device and an unmanned aerial vehicle.

Background

Along with the development of unmanned aerial vehicle technique, unmanned aerial vehicle can play more and more important effect in the middle of each field of each trade at home and abroad, and at present, unmanned aerial vehicle often can run into following problem, specifically:

1) when the unmanned aerial vehicle flies, if the rotor wing of the unmanned aerial vehicle is damaged, the unmanned aerial vehicle is often crashed, loss is caused to a user, and meanwhile, the life safety of people in the crash place is endangered;

2) when unmanned aerial vehicle lands and carries out the operation in a certain place and finishes, then when preparing to take off and return journey, if the rotor takes place to damage, make unmanned aerial vehicle can not normally take off to make unmanned aerial vehicle can not normally return, cause the loss for the user.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art and provides an unmanned aerial vehicle fly-back device and an unmanned aerial vehicle.

The technical scheme of the unmanned aerial vehicle fly-back device is as follows:

the foldable propeller comprises a connecting piece, a motor, a rotor wing, a telescopic device, a trigger part and at least two foldable blades;

the bottom end of the connecting piece is connected with an unmanned aerial vehicle body, a cylindrical sliding groove is formed in the connecting piece, the motor is connected in the sliding groove in a sliding mode, a rotating shaft of the motor penetrates out of the top end of the connecting piece and is connected with the rotor wing, the telescopic device is arranged in the sliding groove and located below the motor, and the telescopic device is used for controlling the motor to move downwards along the sliding groove when the rotor wing is damaged;

the folding blade is also provided with a supporting piece which is used for abutting against the rotor wing when the motor moves downwards along the sliding chute so as to completely separate the rotating shaft from the rotor wing;

one end of the trigger component is arranged in the sliding groove and in the downward movement stroke of the motor, and the trigger component is used for: when triggered, the folding paddle which is connected to the other end of the trigger component and is folded outside the connecting piece is unfolded and connected to the rotating shaft.

The unmanned aerial vehicle missed-flight device has the following beneficial effects:

when the unmanned plane flies or/and when the unmanned plane is ready to take off and return, if the rotor wing of the unmanned plane is damaged, the motor arranged in the connecting piece is controlled by the telescopic device to move downwards along the cylindrical sliding chute arranged in the connecting piece, when the motor moves downwards along the sliding groove, the rotating shaft of the motor is completely separated from the rotor wing through the support piece arranged on the folding paddle to abut against the rotor wing, when the motor moves downwards along the sliding chute, the triggering part with one end arranged in the sliding chute and the other end in the stroke of the downward movement of the motor is triggered, so that the folding paddle blade which is connected with the other end of the triggering part and is folded at the outer side of the connecting piece is unfolded and connected on the rotating shaft, at the moment, the folding paddle blade synchronously rotates along with the rotating shaft to continuously provide lift force for the unmanned aerial vehicle, so as to ensure that the unmanned plane can normally fly or/and take off, reduce the loss of users and not endanger the life safety of other people.

On the basis of the scheme, the unmanned aerial vehicle missed approach device can be further improved as follows.

Furthermore, the folding paddle comprises a folding part and a fixing part, the supporting part is arranged on the fixing part, and a 90-degree self-locking hinge is arranged between the folding part and the fixing part;

an elastic sheet is arranged between the folding part and the connecting piece and is abutted against the folding part;

the other end of the trigger component is fixedly connected with the folding part and compresses the elastic sheet, so that the folding part is folded at the outer side of the connecting piece.

The beneficial effect of adopting the further scheme is that: when the motor moves downwards along the sliding groove, the fixed connection between the other end of the trigger component and the connecting piece can be damaged, the folding piece is unfolded to be in a horizontal state under the acting force of the elastic piece and through the 90-degree self-locking hinge piece, and the folding part cannot shake to ensure that the unmanned aerial vehicle can stably fly.

Furthermore, bosses with circular cross sections are further arranged on the rotating shaft, grooves are formed in the bosses, and the number of the grooves is the same as that of the fixing parts;

the other end of the fixing part is provided with an arc-shaped sheet matched with the boss, convex strips matched with the grooves are arranged in the arc-shaped sheet, and the convex strips correspond to the grooves one to one;

the groove and the raised line are used for clamping when the motor moves downwards along the sliding groove.

The beneficial effect of adopting the further scheme is that: through the joint of recess and sand grip, will fold the paddle and connect in the pivot, guarantee that folding paddle can rotate along with the pivot of motor.

Further, the connecting piece is further provided with a bearing concentric with the rotating shaft, and a connecting rod is arranged between the bearing and the fixing part.

The beneficial effect of adopting the further scheme is that: the folding paddle is connected behind the rotating shaft and can synchronously rotate with the rotating shaft through the bearing.

Further, still including setting up the motor with joint part between the spout, joint part is used for: the relative position between the motor and the chute is fixed before the motor moves downwards along the chute and is destroyed when the motor moves downwards along the chute.

The beneficial effect of adopting the further scheme is that: before the motor moves downwards along the sliding chute, fixing the relative position between the motor and the sliding chute through a clamping component arranged between the motor and the sliding chute, and preventing the motor from moving downwards along the sliding chute; when the motor moves downwards along the sliding groove, the clamping part is damaged to ensure that the motor can smoothly move downwards along the sliding groove.

The unmanned aerial vehicle further comprises a controller, wherein the controller is used for acquiring the lift force of each rotor of the unmanned aerial vehicle, comparing the lift force of each rotor with a preset lift force one by one, and determining whether the rotor is damaged or not according to the comparison result; and determining whether to send an instruction for controlling the motor to move downwards along the sliding chute to the telescopic device or not according to the damage result.

The beneficial effect of adopting the further scheme is that: acquiring the lift force of each rotor wing of the unmanned aerial vehicle, comparing the lift force of each rotor wing with a preset lift force one by one, and determining whether the rotor wing is damaged or not according to the comparison result; whether the command is sent to the telescopic device is determined according to the damage result, and the method is simple and convenient.

Furthermore, the telescopic device is an electromagnet device or a hydraulic telescopic rod.

The beneficial effect of adopting the further scheme is that: when the telescopic device is an electromagnet device, before the motor moves downwards along the chute, the current can be input into the electromagnet device to provide a vertical upward force for the motor so as to prevent the motor from moving downwards along the chute; when the telescopic device is a hydraulic telescopic rod, and before the motor moves downwards along the sliding groove, a vertical upward force is provided for the motor through the hydraulic telescopic rod so as to prevent the motor from moving downwards along the sliding groove.

The technical scheme of the unmanned aerial vehicle provided by the invention is as follows: adopt above-mentioned any one unmanned aerial vehicle device that flies repeatedly.

The unmanned aerial vehicle has the beneficial effects that: when the unmanned plane flies or/and when the unmanned plane is ready to take off and return, if the rotor wing of the unmanned plane is damaged, the motor arranged in the connecting piece is controlled by the telescopic device to move downwards along the cylindrical sliding chute arranged in the connecting piece, when the motor moves downwards along the sliding groove, the rotating shaft of the motor is completely separated from the rotor wing through the support piece arranged on the folding paddle to abut against the rotor wing, when the motor moves downwards along the sliding chute, the triggering part with one end arranged in the sliding chute and the other end in the stroke of the downward movement of the motor is triggered, so that the folding paddle blade which is connected with the other end of the triggering part and is folded at the outer side of the connecting piece is unfolded and connected on the rotating shaft, at the moment, the folding paddle blade synchronously rotates along with the rotating shaft to continuously provide lift force for the unmanned aerial vehicle, so as to ensure that the unmanned plane can normally fly or/and take off, reduce the loss of users and not endanger the life safety of other people.

Drawings

Fig. 1 is a structural diagram of an unmanned aerial vehicle missed approach device according to an embodiment of the present invention;

FIG. 2 is a block diagram of the trigger assembly;

FIG. 3 is a view showing the engagement of the grooves and the ribs.

Detailed Description

As shown in fig. 1, the unmanned aerial vehicle missed approach device according to the embodiment of the present invention includes a connecting member 1, a motor 2, a rotor 3, a telescopic device 4, a triggering member 5, and at least two folding blades;

the bottom end of the connecting piece 1 is connected with an unmanned aerial vehicle body, a cylindrical sliding groove 6 is formed in the connecting piece 1, the motor 2 is connected in the sliding groove 6 in a sliding mode, a rotating shaft 7 of the motor 2 penetrates out of the top end of the connecting piece 1 and is connected with the rotor wing 3, the telescopic device 4 is arranged in the sliding groove 6 and located below the motor 2, and the telescopic device 4 is used for controlling the motor 2 to move downwards along the sliding groove 6 when the rotor wing 3 is damaged;

a support member 8 is further arranged on the folding blade and used for abutting against the rotor 3 when the motor 2 moves downwards along the sliding chute 6 so as to completely separate the rotating shaft 7 from the rotor 3;

one end of the trigger component 5 is arranged in the sliding groove 6 and in the downward moving stroke of the motor 2, and the trigger component 5 is used for: when triggered, the folding blade, which is connected to the other end of the trigger part 5 and folded outside the link 1, is unfolded and connected to the rotation shaft 7.

When the unmanned aerial vehicle flies or/and when the unmanned aerial vehicle is prepared to take off and return, if the rotor 3 of the unmanned aerial vehicle is damaged, the motor 2 arranged in the connecting piece 1 is controlled to move downwards along the cylindrical sliding groove 6 arranged in the connecting piece 1 through the telescopic device 4, when the motor 2 moves downwards along the sliding groove 6, the support piece 8 arranged on the folding blade is abutted against the rotor 3, the rotating shaft 7 of the motor 2 is completely separated from the rotor 3, and when the motor 2 moves downwards along the sliding groove 6, the triggering part 5 with one end arranged in the sliding groove 6 and the other end in the downward moving stroke of the motor 2 is triggered, the folding blade connected to the other end of the triggering part 5 and folded outside the connecting piece 1 is unfolded and connected to the rotating shaft 7, at the moment, the folding blade rotates synchronously along with the rotating shaft 7, the lifting force is continuously provided for the unmanned aerial vehicle, so as to ensure that the unmanned aerial vehicle can normally fly or/and/or normally, the loss of the user is reduced, and the life safety of other people is not endangered.

In the present application, the missed approach can be understood as follows:

1) when the unmanned aerial vehicle flies, if the rotor wing 3 of the unmanned aerial vehicle is damaged, the unmanned aerial vehicle can keep a normal flying state through the unmanned aerial vehicle re-flying device, and the unmanned aerial vehicle re-flying can be understood as the unmanned aerial vehicle re-flying;

2) when unmanned aerial vehicle lands and carries out the operation in a certain place and finishes, then when preparing to take off and return journey, if rotor 3 takes place to damage, make unmanned aerial vehicle normally take off, make its normal takeoff through the unmanned aerial vehicle device that flies again of this application, also can understand for making unmanned aerial vehicle fly again.

Wherein, unmanned aerial vehicle's body indicates: with rotor 3 on the unmanned aerial vehicle and the relevant part of connecting rotor 3 demolish the remaining part in back, connecting piece 1 accessible welding mode, threaded connection mode are connected with unmanned aerial vehicle's body.

Wherein, the concrete structure of support 8 is: with the concentric annular post of pivot 7 of motor 2, and the accessible simple calculation can obtain the size relation between support piece 8 and the rotor 3, in order to guarantee motor 2 is followed when spout 6 moves down, support piece 8 offsets with rotor 3 so that pivot 7 with rotor 3 separates completely to can set up a plurality of support piece 8.

Wherein, the pivot 7 and the rotor 3 accessible of motor 2 are connected through following structure, specifically:

1) a first opening matched with a rotating shaft 7 of the motor 2 is formed in the middle of the rotor 3, the diameter of the first opening is slightly smaller than that of the rotating shaft 7, and the motor 2 and the rotating shaft 7 are fixed through interference fit between the first opening and the rotating shaft 7 so as to ensure that the rotor 3 and the rotating shaft 7 rotate synchronously;

2) be equipped with the cross section on pivot 7 and be polygonal card platform, be equipped with in the rotor 3 with the second opening of card platform adaptation, carry out the joint to second opening and card platform through interference fit's mode, make rotor 3 and pivot 7 carry out synchronous rotation to the cross section explains as the hexagonal card platform as an example, specifically:

fix the cross section for hexagonal card platform and motor 2's pivot 7 through the welding mode, and be equipped with on rotor 3 with the second opening of card platform adaptation, at this moment, second open-ended cross section also is the hexagon, then carries out the joint with second card platform and second opening through interference fit's mode, in order to guarantee motor 2 is followed before 6 downstream of spout, rotor 3 carries out synchronous rotation with pivot 7, guarantees unmanned aerial vehicle's normal flight.

Wherein, telescoping device 4 is electromagnet device or hydraulic telescoping rod, so:

1) when the telescopic device 4 is an electromagnet device, before the motor 2 moves downwards along the chute 6, current can be input into the electromagnet device to provide a vertical upward force, namely repulsion force, for the motor 2 so as to prevent the motor 2 from moving downwards along the chute 6, and when the motor 2 needs to move downwards along the chute 6, reverse current can be input into the electromagnet device to provide a vertical downward force, namely attraction force, for the motor 2 so that the motor 2 can smoothly move downwards along the chute 6;

wherein, electromagnet device's concrete structure does: winding a copper coil on an iron core, in order to increase the repulsion and the attraction to the motor 2, arranging an iron plate, 304 stainless steel or neodymium iron boron magnet and the like at the bottom of the motor 2, establishing a model for an electromagnet device, the iron plate arranged on the motor 2, 304 stainless steel or neodymium iron boron magnet through finite element software such as ANSYS or MAXWELL and the like, thereby accurately calculating the repulsion and the attraction to the motor 2, calculating currents respectively corresponding to the repulsion and the attraction, and inputting the current which does not pass through the electromagnet device so as to achieve the purpose that the motor 2 moves downwards along the chute 6;

it can be understood that: because be interference fit between pivot 7 and the rotor 3, can carry out the contrast experiment many times in advance to guarantee under electromagnet device's suction, make support piece 8 offset with rotor 3, in order to guarantee pivot 7 with rotor 3 separates completely.

2) When the telescopic device 4 is a hydraulic telescopic rod and before the motor 2 moves downwards along the chute 6, a vertical upward force is provided for the motor 2 through the hydraulic telescopic rod to prevent the motor 2 from moving downwards along the chute 6, and when the motor 2 needs to move downwards along the chute 6, a vertical downward force is provided for the motor 2 through the hydraulic telescopic rod to enable the motor 2 to smoothly move downwards along the chute 6;

it can be understood that: because be interference fit between pivot 7 and the rotor 3, can carry out the contrast experiment many times in advance to guarantee under hydraulic telescoping rod's effort, make support piece 8 offset with rotor 3, in order to guarantee pivot 7 with rotor 3 separates completely.

Preferably, in the above technical solution, the folding blade includes a folding portion 9 and a fixing portion 10, the fixing portion 10 is provided with the supporting member 8, and a 90-degree self-locking hinge 11 is provided between the folding portion 9 and the fixing portion 10;

an elastic sheet 12 is further arranged between the folding part 9 and the connecting piece 1, and the elastic sheet 12 is abutted against the folding part 9;

the other end of the trigger component 5 is fixedly connected with the folding part 9 and compresses the elastic sheet 12, so that the folding part 9 is folded at the outer side of the connecting piece 1.

When the motor 2 moves downwards along the sliding groove 6, the fixed connection between the other end of the trigger part 5 and the connecting part 1 can be damaged, so that the folding part is unfolded to be in a horizontal state under the action force of the elastic sheet 12 and through the 90-degree self-locking hinge part 11, and the folding part 9 cannot shake to ensure that the unmanned aerial vehicle can fly stably.

The triggering component 5 is specifically of the following structure:

as shown in fig. 2, the triggering component 5 is a straight rod 20, a first end of the straight rod 20 penetrates through the wall of the connecting piece 1, the straight rod is arranged in the sliding groove 6 and located in the downward movement stroke of the motor 2, a second end of the straight rod 20 is provided with a hook portion 22, a hook 21 is arranged on the folding portion 9, and the hook 21 and the hook portion 22 are connected to realize the connection between the triggering component 5 and the folding portion 9;

when the motor 2 moves downwards along the sliding groove 6, the bottom of the motor 2 triggers the first end, at the moment, the straight rod 20 is equivalent to a lever, the lever takes the wall of the connecting piece 1 as a fulcrum, the second end moves along the direction shown by the arrow in fig. 2, namely, moves along the anticlockwise direction, so that the hook portion 22 and the hook portion 22 are separated from each other, at the moment, the acting force of the elastic piece 12 and the self-locking hinge piece 11 through 90 degrees are unfolded to be in a horizontal state, and the folding portion 9 cannot shake, so that the unmanned aerial vehicle can fly stably.

Wherein, 90 degrees auto-lock articulated elements 11 can refer to folding hinge, and exert an effort that shell fragment 12 is promptly to folding portion 9, and this effort that shell fragment 12 is promptly is greater than, during 90 degrees auto-lock articulated elements 11's hinge power, just can make folding portion 9 expand completely and folding portion 9 can not take place to rock to guarantee that the unmanned aerial vehicle can fly steadily.

Wherein, the one end accessible welding mode fixed connection of shell fragment 12 is on connecting piece 1, and the other end and the folded portion 9 butt of shell fragment 12, and the butt can be understood as: the other end of the spring 12 is in contact with the folded part 9, but is not fixedly connected, and at this time, when the trigger part 5 is triggered, the spring 12 does not rotate along with the folded part 9.

Preferably, in the above technical solution, the rotating shaft 7 is further provided with a boss 13 having a circular cross section, the boss 13 is provided with grooves 14, and the number of the grooves 14 is the same as the number of the fixing portions 10;

an arc-shaped piece 15 matched with the boss 13 is arranged at the other end of the fixing part 10, convex strips 16 matched with the grooves 14 are arranged in the arc-shaped piece 15, and the convex strips 16 correspond to the grooves 14 one by one;

the grooves 14 and the protruding strips 16 are used for clamping when the motor 2 moves downwards along the sliding chute 6, and the number of the grooves 14 and the number of the fixing parts 10 are two, as shown in fig. 3, specifically:

when needing motor 2 to move down along spout 6, boss 13 receives the vertical decurrent power that telescoping device 4 provided, and because pivot 7 is rotating, can make the automatic joint of sand grip 16 to spout 6, through the joint of recess 14 and sand grip 16, connects folding paddle leaf in pivot 7, guarantees that folding paddle leaf can rotate along with motor 2's pivot 7. And along with motor 2 along 6 downstream of spout, make the area of contact of sand grip 16 with 6 joint of spout bigger and bigger, further guarantee that folding paddle can carry out steady rotation along with motor 2's pivot 7.

Preferably, in the above technical solution, the connecting member 1 is further provided with a bearing 17 concentric with the rotating shaft 7, and a connecting rod 18 is arranged between the bearing 17 and the fixing portion 10.

The folding paddle is connected behind the rotating shaft 7 and can rotate synchronously with the rotating shaft 7 through a bearing 17.

The bearing 17 can be fixed on the radial outer side of the connecting piece 1 in a welding mode, two ends of the connecting rod 18 are respectively connected with the fixing part 10 and the bearing 17 in a welding mode or a threaded connection mode, and the fixing part 10 is fixed through the connecting rod 18 before the motor 2 moves downwards along the sliding chute 6; after the motor 2 moves downwards along the chute 6, the fixing part 10 is connected to the rotating shaft 7 through the rotation of the bearing 17 to ensure that the folding blade rotates synchronously with the rotating shaft 7.

Preferably, in the above technical solution, the electric vehicle further includes a clamping member 19 disposed between the motor 2 and the chute 6, wherein the clamping member 19 is configured to: the relative position between the motor 2 and the chute 6 is fixed before the motor 2 moves down along the chute 6 and is broken when the motor 2 moves down along the chute 6.

Before the motor 2 moves downwards along the sliding chute 6, the relative position between the motor 2 and the sliding chute 6 is fixed through a clamping component 19 arranged between the motor 2 and the sliding chute 6, so that the motor 2 is prevented from moving downwards along the sliding chute 6; when the motor 2 moves down along the chute 6, the catching part 19 is broken to ensure that the motor 2 can smoothly move down along the chute 6.

Wherein, the clamping part 19 can be the following structure, specifically:

1) the joint part 19 is the ya keli stick, and the diameter of ya keli stick can choose within 1mm-3mm, through the knowledge of structural mechanics, calculates the shear stress of ya keli stick, so:

when the telescopic device 4 is an electromagnet device, the shearing stress provides guidance for the design of the electromagnet device, so that the resultant force of the attraction force provided by the electromagnet device and the gravity of the motor 2 is greater than the shearing stress of the acrylic rod, and the clamping component 19 can be damaged when the motor 2 moves downwards along the chute 6, so that the motor 2 can smoothly move downwards along the chute 6;

when the telescopic device 4 is a hydraulic telescopic rod, the shearing stress provides guidance for the selection of the hydraulic telescopic rod, so that the resultant force of the force provided for the hydraulic telescopic rod and the gravity of the motor 2 is greater than the shearing stress of the acrylic rod, and the clamping part 19 can be damaged when the motor 2 moves downwards along the chute 6, so that the motor 2 can smoothly move downwards along the chute 6;

2) the clip member 19 is: a first friction belt is wound on the motor 2, a second friction belt is arranged in the chute 6 and at a position corresponding to the first friction belt, and the motor 2 is clamped through friction force generated between the first friction belt and the second friction belt;

when the telescopic device 4 is an electromagnet device, the magnitude of the friction force is obtained through experiments, guidance is provided for the design of the electromagnet device, and the resultant force of the attraction force provided by the electromagnet device and the gravity of the motor 2 is larger than the friction force, so that the clamping part 19 can be damaged when the motor 2 moves downwards along the chute 6, and the motor 2 can be ensured to move downwards smoothly along the chute 6;

when telescoping device 4 is hydraulic telescoping rod, obtain the size of frictional force through the experiment, for hydraulic telescoping rod's the selection for use provides the guidance, make the resultant force of the power that provides for hydraulic telescoping rod and the gravity of motor 2 be greater than the frictional force, could guarantee when motor 2 moves down along spout 6, destroy joint part 19 to guarantee that motor 2 can move down along spout 6 smoothly.

Preferably, in the above technical solution, the unmanned aerial vehicle further includes a controller, the controller is configured to acquire a lift force of each rotor 3 of the unmanned aerial vehicle, compare the lift force of each rotor 3 with a preset lift force one by one, and determine whether the rotor 3 is damaged according to a comparison result; and determining whether to send an instruction for controlling the motor 2 to move downwards along the chute 6 to the telescopic device 4 according to the damage result.

Acquiring the lift force of each rotor wing 3 of the unmanned aerial vehicle, comparing the lift force of each rotor wing 3 with a preset lift force one by one, and determining whether the rotor wing 3 is damaged or not according to the comparison result; whether the instruction is sent to the telescopic device 4 is determined according to the damage result, and the method is simple and convenient, and specifically comprises the following steps:

1) when the lift force of at least one rotor 3 of the unmanned aerial vehicle is smaller than the preset lift force, determining that at least one rotor 3 is damaged, and sending a command for controlling the motor 2 to move downwards along the sliding groove 6 to the telescopic device 4 corresponding to the at least one rotor 3;

2) when the lift force of each rotor wing 3 of the unmanned aerial vehicle is greater than the preset lift force, it is determined that no rotor wing 3 is damaged, and at the moment, a command for controlling the motor 2 to move downwards along the sliding groove 6 is not sent to the telescopic device 4;

wherein, supposing that the unmanned aerial vehicle has 4 rotors 3, as is well known, when the resultant force of the lift forces of the 4 rotors 3 is greater than the gravity of the unmanned aerial vehicle, the unmanned aerial vehicle can take off, so that the lift force of each rotor 3 is G/4, wherein G represents the gravity of the unmanned aerial vehicle, and the preset lift force can be set to be G/4;

wherein, the lift of each rotor 3 can be obtained by arranging a pressure sensor on each connecting piece 1, specifically:

1) the piezoelectric sensor can be arranged on the folding blade, particularly the fixing part 10 of the folding blade, when the rotor 3 rotates, a downward acting force can be generated, at the moment, the acting force can enable the piezoelectric sensor to generate an electric signal, the lifting force of each rotor 3 can be obtained by analyzing the electric signal, before the piezoelectric sensor is applied, the functional relation between the electric signal returned by the pressure sensor and the lifting force can be accurately obtained through multiple comparison experiments, when the piezoelectric sensor is used, the lifting force of each rotor 3 can be accurately obtained through the functional relation, and therefore a more accurate comparison result can be obtained;

2) a high-precision pressure sensor can be arranged on the folding blade, particularly on the fixing part 10 of the folding blade, for example, the precision is +/-0.05% FS, +/-0.025% FS, etc., when the rotor 3 rotates, a downward acting force can be generated, and the lift force of each rotor 3 can be accurately obtained through the high-precision pressure sensor;

3) the lift of each rotor 3 can be calculated by monitoring the airflow through the rotors 3 of the drone using a light pressure sensor developed by AERS-Midwest.

In the present invention, the directions of "up" and "down" are referred to in the specification with reference to fig. 1.

The unmanned aerial vehicle of the embodiment of the invention adopts any one of the above mentioned unmanned aerial vehicle fly-back devices,

when the unmanned aerial vehicle flies or/and when the unmanned aerial vehicle is prepared to take off and return, if the rotor 3 of the unmanned aerial vehicle is damaged, the motor 2 arranged in the connecting piece 1 is controlled to move downwards along the cylindrical sliding groove 6 arranged in the connecting piece 1 through the telescopic device 4, when the motor 2 moves downwards along the sliding groove 6, the support piece 8 arranged on the folding blade is abutted against the rotor 3, the rotating shaft 7 of the motor 2 is completely separated from the rotor 3, and when the motor 2 moves downwards along the sliding groove 6, the triggering part 5 with one end arranged in the sliding groove 6 and the other end in the downward moving stroke of the motor 2 is triggered, the folding blade connected to the other end of the triggering part 5 and folded outside the connecting piece 1 is unfolded and connected to the rotating shaft 7, at the moment, the folding blade rotates synchronously along with the rotating shaft 7, the lifting force is continuously provided for the unmanned aerial vehicle, so as to ensure that the unmanned aerial vehicle can normally fly or/and/or normally, the loss of the user is reduced, and the life safety of other people is not endangered.

In the present invention, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.