Propeller Folding Device for an Aerial Vehicle

Abstract

A propeller folding device for an aerial vehicle that unfolds or folds propeller blades according to the flight state of the aerial vehicle. The propeller blades are efficiently used according to the flight state of the aerial vehicle. The energy efficiency and ferry range of the aerial vehicle are improved.

Description

Technical Field

[0001] The present invention generally relates to a propeller folding device for an aerial vehicle, and more particularly, to a propeller folding device for an aerial vehicle that can deploy or fold a propeller according to the flight state of the aerial vehicle. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not constitute prior art.

[0003] In recent years, the development of aerial vehicles that can be used for various purposes (such as cargo transportation or medical transportation) is underway. Due to their improved energy efficiency and reliability, flying vehicles are entering the stage of practical use.

[0004] Such an aerial vehicle can fly by operating a propeller, and the propeller can also achieve takeoff and landing. Takeoff and landing require greater thrust and higher propeller revolutions per minute than during flight. Conversely, when the aerial vehicle is in a flight state, some operations of the propeller for vertical takeoff are no longer required. The applicant has found that when the aerial vehicle is in a high-speed flight state, the propeller generates air resistance, resulting in energy loss during flight.

[0005] The above statements are merely intended to help understand the background art of the present invention and are not intended for the present invention to fall within the scope of the prior art known to those skilled in the art. Summary of the Invention

[0006] The present invention provides a propeller folding device for an aerial vehicle. In particular, the propeller folding device can deploy or fold the propeller blades according to the flight state of the aerial vehicle, so that the propeller blades can be efficiently used according to the flight state of the aerial vehicle, thereby improving the energy efficiency and ferry range of the aerial vehicle.

[0007] In one aspect of the present invention, a propeller folding device for an aerial vehicle includes: a lower plate, an upper plate, and a guide member. The lower plate is connected to the drive shaft of a drive motor that generates a rotational force. The lower plate includes a pivot unit on which a propeller blade is mounted. The pivot unit is configured to be pivotable so that the propeller blade can be deployed or folded according to the position of the pivot unit. The upper plate is disposed on the lower plate to move in the upward and downward directions, such that the upper plate allows the pivot unit to pivot or fixes the position of the pivot unit. The guide member is coupled to the upper plate and connected to the pivot unit to change the pivot position of the pivot unit in response to the movement of the upper plate in the upward and downward directions, thereby deploying or folding the propeller blade.

[0008] The propeller folding device may further include: a sub-motor including a sub-shaft coupled to the upper plate, wherein the sub-motor moves the sub-shaft in the upward and downward directions to adjust the position of the upper plate in the upward and downward directions.

[0009] The drive shaft may be coupled to the bottom of the lower plate, a connecting shaft extending downward from the upper plate may be connected to the top of the lower plate, and the drive shaft and the connecting shaft may be arranged coaxially with each other.

[0010] The drive shaft may have a cylindrical shape with a hollow interior. The connecting shaft may be inserted through the lower plate into the hollow interior of the drive shaft.

[0011] The lower plate may have a polygonal through-hole, and the connecting shaft extends through the through-hole. The connecting shaft may include: a top end portion having a polygonal shape to match the polygonal through-hole, and a bottom end portion formed to match the hollow interior of the drive shaft.

[0012] The sub-motor may be disposed below the drive motor, and the sub-shaft may be inserted into the drive shaft to be connected to the connecting shaft.

[0013] The sub-shaft and the connecting shaft may be connected to each other via a bearing such that the sub-shaft is non-rotatable while the connecting shaft is rotatable.

[0014] The pivot unit may include: a mounting end portion on which the propeller blade is mounted and a pivot end portion pivotally disposed on the lower plate, and a guide pin projects from a peripheral portion of the pivot end portion. The guide member may be configured to surround the pivot end portion and have a guide hole into which the guide pin is inserted, and the guide hole extends along a path in the upward and downward directions.

[0015] The guide hole may include: a linear segment extending in the upward and downward directions; and an inclined segment extending downward from the linear segment.

[0016] The linear segment may extend to a length that allows the pivot unit to pivot when the upper plate moves upward. The inclination angle and length of the inclined segment may be determined such that the pivot unit pivots in response to the upward movement of the upper plate, thereby folding the propeller blade.

[0017] The lower plate may include a lower stopper disposed around the pivot unit, such that when the propeller blade moves to the deployed position or the folded position in response to the pivot of the pivot unit, the lower stopper restricts the pivot of the pivot unit.

[0018] The lower stopper may extend to surround a portion of the pivot unit, and the lower stopper may be configured to contact the mounting end portion of the pivot unit when the propeller blade moves to the deployed position or the folded position.

[0019] The upper plate may include an upper stopper that extends downward and allows the pivot unit to be seated therein. The upper stopper may be configured to fix the position of the pivot unit when the upper plate moves downward.

[0020] The propeller folding device of the aerial vehicle having the above structure can deploy or fold the propeller blades according to the flight state of the aerial vehicle. The propeller blades can be efficiently used according to the flight state of the aerial vehicle, thereby improving the energy efficiency and ferry range of the aerial vehicle.

[0021] Through the description provided herein, other application fields will become apparent. It should be understood that the present specification and specific embodiments are only for illustrative purposes and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To better understand the present invention, reference is now made to the accompanying drawings, which illustrate various forms thereof by way of example, in which:

[0023] Figure 1 and Figure 2 is a view showing the deployed state of the propeller folding device of the aerial vehicle according to one form of the present invention;

[0024] Figure 3 is a view showing the drive shaft and the connecting shaft of the propeller folding device of the aerial vehicle shown in Figure 1 ;

[0025] Figure 4 is a view showing the lower plate and the pivot unit of the propeller folding device of the aerial vehicle;

[0026] Figures 5 to 7 is a view showing the operation of the pivot unit of the propeller folding device of the aerial vehicle; and

[0027] Figure 8 is a view showing the folded state of the propeller folding device of the aerial vehicle according to one form of the present invention.

[0028] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. DETAILED DESCRIPTION

[0029] The following description is merely exemplary in nature and is not intended to limit the invention, its application, or uses. It should be understood that throughout the specification and the drawings, corresponding reference numerals denote the same or corresponding components and features.

[0030] Hereinafter, the propeller folding device of the aerial vehicle according to an exemplary form of the present invention will be described in detail with reference to the drawings.

[0031] Figure 1 And Figure 2 is a view showing an unfolded state of a propeller folding device of an aerial vehicle according to one form of the present invention; Figure 3 is a view showing Figure 1 the drive shaft and the connecting shaft of the propeller folding device of the aerial vehicle shown in; Figure 4 is a view showing a lower plate and a pivot unit of the propeller folding device of the aerial vehicle; Figures 5 to 7 is a view showing the operation of the pivot unit of the propeller folding device of the aerial vehicle; and Figure 8 is a view showing a folded state of a propeller folding device of an aerial vehicle according to another form of the present invention.

[0032] As Figure 1 and Figure 2 shown, the propeller folding device of the aerial vehicle includes: a lower plate 200, an upper plate 300, and a guide 310. The lower plate 200 is connected to a drive shaft 110 of a drive motor 100 that generates a rotational force, and includes a pivot unit 210 on which a propeller blade P is mounted. The pivot unit 210 is configured to be pivotable so that the propeller blade P can be unfolded or folded according to the position of the pivot unit 210. The upper plate 300 is disposed on the lower plate 200 and is movable in the up and down directions, such that the upper plate 300 allows the pivot unit 210 to pivot or fixes the position of the pivot unit 210. The guide 310 is coupled to the upper plate 300 and is connected to the pivot unit 210, so as to change the pivot position of the pivot unit 210 corresponding to the movement of the upper plate 300 in the up and down directions, thereby unfolding or folding the propeller blade. Here, the drive motor 100 and a sub-motor 400 (to be described later) can operate under the control of a motor controller.

[0033] The propeller folding device according to the present invention can be disposed on the body or the flank of the aerial vehicle. When the drive motor 100 operates, the lower plate 200 rotates to rotate the propeller blade P, thereby generating thrust so that the aerial vehicle can fly.

[0034] Although the upper plate 300, the lower plate 200, and the drive motor 100 are shown in the drawings as being arranged in a top-down direction, those components can be arranged in reverse. In addition, a plurality of propeller blades P can be provided on the lower plate 200 via the pivot unit 210. Some of the propeller blades P can be arranged on the lower plate 200 via the pivot unit 210 to be unfolded or folded.

[0035] The drive motor 100 includes a drive shaft 110, and the lower plate 200 is connected to the drive shaft 110 so that the lower plate 200 rotates by the rotational force of the drive motor 100 transmitted thereto. A pivot unit 210 on which a propeller blade P is mounted may be pivotally arranged on the lower plate 200 so that the propeller blade P can be deployed or folded according to the pivot position of the pivot unit 210. The pivot position of the pivot unit 210 is fixed by an upper plate 300 arranged on the lower plate 200 and movable in the upward and downward directions. Accordingly, the pivot position of the pivot unit 210 is fixed by the upper plate 300 so that the propeller blade P can be kept deployed or folded. In particular, a guide 310 of the upper plate 300 is connected to the pivot unit 210 to change the pivot position of the pivot unit 210 according to the movement of the upper plate 300 in the upward and downward directions.

[0036] Here, the propeller folding device further includes a sub-motor 400, and the sub-motor 400 includes a sub-shaft 410 coupled to the upper plate 300. The sub-shaft 410 is configured to move in the upward and downward directions to adjust the position of the upper plate 300 in the upward and downward directions. Accordingly, the position of the upper plate 300 in the upward and downward directions can be adjusted according to whether the sub-motor 400 operates, thereby changing the pivot position of the pivot unit 210 or fixing the position of the pivot unit 210.

[0037] For example, when the upper plate 300 moves upward in response to the operation of the sub-motor 400, a change in the pivot position of the pivot unit 210 can be allowed, and the guide 310 of the upper plate 300 can pivot the pivot unit 210 to fold the propeller blade P. Accordingly, the air resistance caused by the propeller blade P during high-speed flight of the aerial vehicle can be reduced, enabling the aerial vehicle to fly efficiently. In addition, when storing the aerial vehicle, the propeller blade P can be folded to reduce the storage space.

[0038] Conversely, when the upper plate 300 moves downward, the guide 310 pivots the pivot unit 210 to deploy the propeller blade P, and the change in the pivot position of the pivot unit 210 is restricted by the upper plate 300. Accordingly, the aerial vehicle can take off and land by the rotation of the propeller blade P in response to the operation of the drive motor 100. Since the position of the propeller blade P is fixed by the upper plate 300, the reliability of the propeller blade P is ensured.

[0039] The present invention will be described in more detail below, as Figure 2As shown, the drive shaft 110 is coupled to the bottom of the lower plate 200, and the connecting shaft 320 extending downward from the upper plate 300 is connected to the top of the lower plate 200 to be coaxial with the drive shaft 110. Here, the lower plate 200 may have a plate shape, and a plurality of pivot units 210 are provided at the peripheral portion of the lower plate 200, and the propeller blades P are respectively mounted on the pivot units 210. Since the drive shaft 110 and the connecting shaft 320 are respectively connected to the bottom and the top of the central portion of the lower plate 200, and the drive shaft 110 and the connecting shaft 320 are coaxial, the drive shaft 110, the lower plate 200, and the connecting shaft 320 can be reliably rotated by the rotational force provided by the drive motor 100. The upper plate 300 may also have a plate shape similar to that of the lower plate 200, and the connecting shaft 320 may extend from the central portion of the upper plate 300.

[0040] As Figure 3 shown, the drive shaft 110 has a hollow cylindrical shape, and the connecting shaft 320 is inserted into the drive shaft 110 through the lower plate 200. Due to this configuration, the connecting shaft 320 is connected to both the lower plate 200 and the drive shaft 110, thereby obtaining the coupling strength of the connecting shaft 320, so that the upper plate 300 can be firmly fixed to the lower plate 200. In addition, since the connecting shaft 320 is inserted into the drive shaft 110, the strength of the drive shaft 110 having a hollow interior can be increased.

[0041] In one form, as Figure 4 shown, the lower plate 200 has a polygonal through-hole 220, and the connecting shaft 320 extends through the through-hole 220. The connecting shaft 320 is configured such that its top portion has a polygonal shape to match the through-hole 220, and its bottom portion matches the hollow interior of the drive shaft 110. Therefore, the connecting shaft 320 of the upper plate 300 can be inserted into the drive shaft 110 through the through-hole 220 of the lower plate 200. In particular, since the top portion of the through-hole 220 and the top portion of the connecting shaft 320 are polygonal, the connecting shaft 320 can rotate with the lower plate 200 and allows the connecting shaft 320 to move up and down in the through-hole 220. The bottom portion of the connecting shaft 320 may have a circular shape that matches the hollow interior of the drive shaft 110. Accordingly, the upper plate 300 is disposed on the lower plate 200 via the connecting shaft 320 to be movable in the upward and downward directions and rotatable with the lower plate 200.

[0042] The auxiliary motor 400 is disposed below the driving motor 100, and the auxiliary shaft 410 is inserted into the driving shaft 110 to be connected to the connecting shaft 320. Accordingly, moving the auxiliary shaft 410 by the operation of the auxiliary motor 400 can move the connecting shaft 320. Here, the auxiliary motor 400 may be implemented as an actuator that retracts or extends the auxiliary shaft 410 in a linear direction. Since the auxiliary shaft 410 is inserted into the driving shaft 110 and connected to the connecting shaft 320, the connecting shaft 320 can be moved by the linear movement of the auxiliary shaft 410, so that the upper plate 300 can be moved in the upward and downward directions. Although the auxiliary motor 400 may be disposed on the lower plate 200, problems may occur when the auxiliary motor 400 is disposed on the lower plate 200 configured to rotate. In this regard, the auxiliary motor 400 is separately disposed below or at the bottom of the driving motor 100, and the auxiliary shaft 410 of the auxiliary motor 400 passes through the hollow interior of the driving shaft 110 and is connected to the connecting shaft 320. Accordingly, the volume of the housing including the motor can be reduced.

[0043] Here, the auxiliary shaft 410 and the connecting shaft 320 are connected to each other via a bearing B. The auxiliary shaft 410 is connected to the auxiliary motor 400 to linearly move in the upward and downward directions without rotation. The connecting shaft 320 is connected to the upper plate 300 such that the connecting shaft 320 can rotate while linearly moving in the upward and downward directions. Accordingly, the distal end of the auxiliary shaft 410 may be configured such that the distal end of the connecting shaft 320 is inserted therein. The bearing B is interposed between the auxiliary shaft 410 and the connecting shaft 320 such that the connecting shaft 320 is rotatable relative to the auxiliary shaft 410.

[0044] The pivoting operation of the pivoting unit 210 will be described below. Each pivoting unit 210 includes: a mounting end 211 on which a corresponding propeller blade P of the propeller blades is mounted; and a pivoting end 212 that is pivotally disposed on the lower plate 200. A guide pin 212a projects from a peripheral portion of the pivoting end 212. Each guide member 310 is configured to surround the corresponding pivoting end 212. The guide member 310 may have a guide hole 311 into which the guide pin 212a is inserted. The guide hole 311 may extend in the upward and downward directions along a path.

[0045] As Figure 5As shown, each pivot unit 210 includes: a mounting end 211 to which the corresponding propeller blade P is mounted and fixed; and a pivot end 212 which is pivotally arranged on the lower plate 200. The mounting end 211 of the pivot unit 210 may have a shape that encloses the propeller blade P, such that the propeller blade P is firmly fixed thereto, or such that the propeller blade P can be fastened by bolt connection or riveting or welding, so that the propeller blade P is integrally coupled thereto. The pivot end 212 is integrally coupled to the mounting end 211 and is pivotally arranged on the lower plate 200, such that the position of the propeller blade P can be changed according to the pivot position. The pivot end 212 may have a cylindrical shape and includes a guide pin 212a inserted into a guide hole 311 of the guide member 310. In particular, since the guide hole 311 of the guide member 310 extends along a path, when the guide member 310 moves as the upper plate 300 moves in the upward and downward directions, the guide pin 212a moves along the path of the guide hole 311, thereby changing the pivot position of the pivot unit 210.

[0046] In some forms, as Figures 5 to 7 shown, the guide hole 311 includes: a linear segment 311a which extends in the upward and downward directions; and an inclined segment 311b which extends downward from the linear segment 311a.

[0047] That is, the linear segment 311a of the guide hole 311 causes the guide pin 212a to move only in the upward and downward directions along the linear segment 311a, so that the pivot position of the pivot unit 210 remains unchanged. Since only the position of the upper plate 300 changes in the upward and downward directions, the pivot unit 210 can be allowed to pivot, or the position of the pivot unit 210 can be fixed. Accordingly, the linear segment 311a may extend to a length that allows the pivot unit 210 to pivot when the upper plate 300 moves upward.

[0048] The inclined segment 311b extends obliquely from the linear segment 311a. Therefore, when the guide pin 212a moves along the inclined segment 311b in response to the movement of the upper plate 300 in the upward and downward directions, the pivot position of the pivot unit 210 can be changed in the direction in which the inclined segment 311b extends. The inclination angle and length of the inclined segment 311b can be determined such that the pivot unit 210 pivots in response to the upward movement of the upper plate 300, so that the propeller blade P is folded.

[0049] As described above, the configuration of the linear segment 311a and the inclined segment 311b of the guide hole 311 can be changed according to the rotational speed and rotational angle of the propeller blade P in response to the movement of the upper plate 300 in the upward and downward directions.

[0050] Therefore, as Figure 6As shown, when the upper plate 300 moves upward, the guide 310 also moves upward, causing the guide pin 212a to move along the linear section 311a of the guide hole 311. Accordingly, the pivoting position of the pivoting unit 210 is allowed to change relative to the upper plate 300.

[0051] As Figure 7 shown, when the upper plate 300 continues to move upward, the guide pin 212a enters the inclined section 311b of the guide hole 311 and then moves along the inclined section 311b. Accordingly, the pivoting position of the pivoting unit 210 can be changed such that the propeller blade P can be folded or unfolded.

[0052] Return Figure 4 , the lower plate 200 includes a lower stopper 230 surrounding the pivoting unit 210. When the propeller blade P moves to the unfolded position or the folded position in response to the pivoting of the pivoting unit 210, the lower stopper 230 restricts the pivoting of the pivoting unit 210. When the propeller blade P moves to the unfolded position or the folded position, the lower stopper 230 is provided on the portion of the lower plate 200 that contacts the pivoting unit 210. The lower plate 200 may be configured to contact the mounting end 211 of the pivoting unit 210. The lower plate 200 and the mounting end 211 of the pivoting unit 210 may be configured to be in surface contact with each other.

[0053] In addition, each lower stopper 230 extends to surround a portion of the corresponding pivoting unit 210. The lower stopper 230 is configured to contact the mounting end 211 of the pivoting unit 210 when the propeller blade P moves to the unfolded position or the folded position. As described above, since the lower stopper 230 is configured to extend along the circumference of the pivoting unit 210, the strength of the lower stopper 230 that supports the pivoting unit 210 is obtained, thereby improving the stability of the pivoting unit 210.

[0054] In addition, the upper plate 300 includes an upper stopper 330 that extends downward and allows the pivoting unit 210 to be seated therein respectively. When the upper plate 300 moves downward, the position of the pivoting unit 210 is fixed by the upper stopper 330. Accordingly, the upper stopper 330 of the upper plate 300 may have seating portions 340 that surround and seat the pivoting unit 210 therein respectively. Since the pivoting unit 210 is seated on the upper plate 300 in this manner, when the propeller blade P is rotated by the operation of the drive motor 100, the upper plate 300 can fix the pivoting unit 210 such that the propeller blade P can rotate at high speed and vibration can be reduced.

[0055] The propeller folding device of the aerial vehicle according to an exemplary form of the present invention as described above can operate as follows.

[0056] As Figure 1As shown, at the position where the propeller blade P is deployed, the upper plate 300 moves downward toward the lower plate 200 to contact the pivot unit 210, thereby fixing the position of the pivot unit 210. In this position, the aerial vehicle can be in a vertical takeoff or landing position.

[0057] When the propeller blade P is folded, the secondary shaft 410 moves the connecting shaft 320 in response to the operation of the secondary motor 400, thereby moving the upper plate 300 upward, such that the pivoting position of the pivot unit 210 is in a state where it can be changed. In addition, the guide 310 moves upward together with the upper plate 300, and the guide pins 212a respectively enter the inclined section 311b and move along the inclined section 311b, such that the pivoting position of the pivot unit 210 is changed. Thus, as Figure 8 shown, the propeller blade P pivots together with the pivot unit 210 and is thus folded up. In this position, the aerial vehicle can fly at high speed in the air.

[0058] As described above, the propeller folding device of the aerial vehicle according to some forms of the present invention can deploy or fold the propeller blade according to the flight state of the aerial vehicle. The propeller blade can be efficiently used according to the flight state of the aerial vehicle, thereby improving the energy efficiency and ferry range of the aerial vehicle.

[0059] Although exemplary forms of the present invention have been described for purposes of illustration, those skilled in the art should understand that various modifications, additions, and deletions are possible without departing from the scope and spirit of the present invention.

Claims

1. A propeller folding device for an air vehicle, the propeller folding device comprising: A lower plate connected to a drive shaft of a drive motor that generates a rotational force, wherein the lower plate comprises: A pivot unit on which a propeller blade is mounted, wherein the pivot unit is configured to pivotally move so that the propeller blade can be deployed or folded according to the position of the pivot unit; An upper plate disposed on the lower plate and configured to move in upward and downward directions such that the upper plate allows the pivot unit to pivot or fixes the position of the pivot unit; and A guide member coupled to the upper plate and connected to the pivot unit, wherein the guide member is configured to change the position of the pivot unit in response to the upper plate moving in upward and downward directions, thereby deploying or folding the propeller blade.

2. The propeller folding device of the aerial vehicle according to claim 1, further comprising: A sub-motor comprising a sub-shaft coupled to the upper plate, wherein the sub-motor is configured to move the sub-shaft in upward and downward directions, thereby adjusting the position of the upper plate in upward and downward directions.

3. The propeller folding device for an air vehicle according to claim 2, wherein: The drive shaft is coupled to the bottom of the lower plate, A connecting shaft extending downward from the upper plate is connected to the top of the lower plate, The drive shaft and the connecting shaft are arranged coaxially with each other.

4. The propeller folding device of the aerial vehicle according to claim 3, wherein, The drive shaft has a cylindrical shape with a hollow interior, and the connecting shaft is inserted through the lower plate into the hollow interior of the drive shaft.

5. The propeller folding device for an air vehicle according to claim 4, wherein: The lower plate has a polygonal through-hole, and the connecting shaft extends through the through-hole. The connecting shaft comprises: A top end portion having a polygonal shape to match the polygonal through-hole, and A bottom end portion formed to match the hollow interior of the drive shaft.

6. The propeller folding device of the aerial vehicle according to claim 4, wherein, The sub-motor is disposed below the drive motor, and the sub-shaft is inserted into the drive shaft to be connected to the connecting shaft.

7. The propeller folding device of the aerial vehicle according to claim 6, wherein, The sub-shaft and the connecting shaft are connected to each other via a bearing such that the sub-shaft is non-rotatable while the connecting shaft is rotatable.

8. The propeller folding device for an air vehicle according to claim 1, wherein: The pivot unit comprises a mounting end portion on which the propeller blade is mounted and a pivot end portion pivotally disposed on the lower plate. A guide pin projects from a peripheral portion of the pivot end portion, The guide member is configured to surround the pivot end portion and has a guide hole into which the guide pin is inserted. The guide hole extends along a path in upward and downward directions.

9. The propeller folding device of the aerial vehicle according to claim 8, wherein, The guide hole comprises: a linear segment extending in upward and downward directions; and an inclined segment extending downward from the linear segment.

10. The propeller folding device of the aerial vehicle according to claim 9, wherein, The linear segment extends to a length that allows the pivot unit to pivot when the upper plate moves upward. The inclination angle and length of the inclined segment are determined such that the pivot unit pivots in response to the upward movement of the upper plate, thereby folding the propeller blade.

11. The propeller folding device for an air vehicle according to claim 8, wherein: The lower plate comprises a lower stop disposed around the pivot unit, When the propeller blade moves to the deployed position or the folded position in response to the pivoting of the pivoting unit, the lower stopper is configured to limit the pivoting of the pivoting unit.

12. The propeller folding device of the aerial vehicle according to claim 11, wherein: The lower stopper extends to surround a part of the pivoting unit, The lower stopper is configured to contact the mounting end of the pivoting unit when the propeller blade moves to the deployed position or the folded position.

13. The propeller folding device of the aerial vehicle according to claim 1, wherein: The upper plate includes an upper stopper that extends downward and allows the pivoting unit to be seated therein, and the upper stopper is configured to fix the position of the pivoting unit when the upper plate moves downward.

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