Unmanned aircraft and wing structure of aircraft

Abstract

An unmanned aircraft according to the present disclosure is provided with an airframe (2) and a main wing (4). The main wing (4) has: a pair of left and right wing body members (12) that are connected to the airframe (2) at the wing root side, and extend in the wing width direction toward the wing tip side; and at least one movable wing member (14) that is provided at the trailing edge of the wing body members (12), and can be displaced relative to the wing body members (12). The at least one movable wing member (14) has a wing root-side portion disposed at the wing root side, and a wing tip-side portion disposed at the wing tip side. The wing tip-side portion has a smaller lift coefficient than the wing root-side portion.

Description

Wing structure of unmanned aircraft and aircraft Related applications

[0001] This application claims the priority of Japanese Patent Application No. 2024-192597 filed on November 1, 2024, and the entire disclosure of which is incorporated herein by reference and made a part of this application.

[0002] The present disclosure relates to a wing structure of an aircraft.

[0003] In the wing of an aircraft, there is one having a twist-down structure in which the angle of attack of the main wing decreases from the wing root toward the wing tip (for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2017-081260

[0005] In order to realize the twist-down structure, the wing cross-sectional shape needs to be continuously changed from the wing root toward the wing tip. Therefore, the wing shape becomes complicated.

[0006] The disclosure of the present application provides a wing structure of an unmanned aircraft and an aircraft that can simplify the wing shape.

[0007] An unmanned aircraft according to one embodiment of the present disclosure includes: a fuselage; a pair of left and right wing body members connected to the fuselage on the wing root side and extending in the wing width direction toward the wing tip side; and a main wing having at least one movable wing member provided on the trailing edge of the wing body member and relatively displaceable with respect to the wing body member. The at least one movable wing member has a wing root side portion disposed on the wing root side and a wing tip side portion disposed on the wing tip side, and the lift coefficient of the wing tip side portion is smaller than that of the wing root side portion.

[0008] A wing structure of an aircraft according to one embodiment of the present disclosure includes: a wing body member connected to the fuselage on the wing root side and extending in the wing width direction toward the wing tip side; and at least one movable wing member provided on the trailing edge of the wing body member and relatively displaceable with respect to the wing body member. The rear end of the proximal side of the at least one movable wing member is disposed higher than the rear end of the proximal side.

[0009] According to the wing structure of this disclosure, the entire wing, including the wing body member and the control surface member, can prevent airflow separation at the wingtip and suppress the sharp decrease in lift that occurs at the wingtip, thereby improving flight stability. Furthermore, by devising the shape of at least one control surface member, the shape of the wing body member can be simplified compared to the case where airflow separation at the wingtip is prevented using only the wing body member.

[0010] Any combination of at least two configurations disclosed in the claims and / or the specification and / or drawings is included in this disclosure. In particular, any combination of two or more of each claim in the claims is included in this disclosure.

[0011] This disclosure will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustrative and explanatory purposes only and should not be used to define the scope of this disclosure. The scope of this disclosure is defined by the accompanying claims. In the accompanying drawings, the same part number in multiple drawings indicates the same part. A perspective view showing an aircraft with a wing structure according to the first embodiment of this disclosure. A magnified perspective view showing the wing structure of the aircraft. A rear view of the wing structure of the aircraft, viewed from the rear. A magnified perspective view showing the area around the movable wing members of the wing structure. A diagram showing the cross-sectional shape of the main wing along line V-V in Figure 4. A diagram showing the cross-sectional shape of the main wing along line VI-VI in Figure 4. A plan view showing an aircraft with a wing structure according to the second embodiment of this disclosure. A diagram showing the cross-sectional shape of the main wing along line VIII-VIII in Figure 7. A diagram showing the cross-sectional shape of the main wing along line IX-IX in Figure 7.

[0012] Preferred embodiments of the present disclosure will be described below with reference to the drawings. Figure 1 shows an aircraft equipped with a wing structure according to the first embodiment of the present disclosure, and Figure 2 shows an enlarged view of the aircraft's wing structure. Figures 3 and 4 are a perspective view and a rear view, respectively, showing enlarged views of the main wing.

[0013] The aircraft of this embodiment can be used as an unmanned aerial vehicle. The aircraft comprises a fuselage 2, which is the main body of the aircraft, and wings 4 connected to the fuselage 2. The fuselage 2 is the main body and extends along the longitudinal direction. The fuselage 2 has a roll axis, a pitch axis, and a yaw axis. The roll axis passes through the center of the fuselage 2 and extends along the longitudinal direction. With respect to a reference position set outside the aircraft, the attitude of each axis changes in accordance with the attitude change of the fuselage 2.

[0014] The main wings 4 are arranged in pairs, one on each side, relative to the fuselage 2. The main wings 4 are connected to the fuselage 2 and extend in the pitch axis direction, which is the left-right direction. One of the pair of main wings 4, the left wing 4L, protrudes to the left from the fuselage 2. The other of the pair of main wings 4, the right wing 4R, protrudes to the right from the fuselage 2. The pitch axis direction corresponds to the wingspan direction WD, which is the width direction of the main wing 4. In the following description, the side of the main wing 4 that is connected to the fuselage 2 is called the "wing root side". The side of the main wing 4 opposite to the wingtip side, i.e., the tip side of the main wing, is called the "wingtip side".

[0015] The main wing 4 generates lift, an upward force, due to the influence of airflow when the aircraft is moving forward. The main wing 4 has an airfoil shape when its cross-sectional shape is perpendicular to the wingspan direction WD. In this embodiment, the main wing 4 has a cross-sectional shape in which the leading edge is formed into a curved shape and the trailing edge is formed into a sharply pointed teardrop shape. The main wing 4 is connected to the fuselage 2 so as to have an angle of attack in order to obtain lift. The angle of attack corresponds to the angle between the chord, which connects the leading edge and the trailing edge, and the direction of thrust. For example, when an aircraft is propelled horizontally in the air, the chord of the main wing 4 slopes downward as it moves backward.

[0016] The aircraft of this embodiment includes a horizontal stabilizer 6 and a vertical stabilizer 8. The horizontal stabilizers 6 are arranged in pairs on the left and right sides of the fuselage 2 and extend in the direction of the pitch axis. The horizontal stabilizers 6 are connected to the fuselage 2 aft of the wing joint where the main wings 4 are connected. The horizontal stabilizers 6 are used to stabilize or control the attitude of the aircraft around the pitch axis. The vertical stabilizer 8 is used to stabilize or control the attitude of the aircraft around the yaw axis.

[0017] The aircraft is equipped with a propulsion system 10 for forward propulsion. In this embodiment, the propulsion system 10 includes a propeller. The rotation axis of the propeller is positioned along the roll axis. The rotor blades on the propeller rotate around the rotation axis, generating thrust to propel the aircraft 2 forward. For example, an electric motor or a reciprocating engine may be used as the drive source for rotating the rotation axis of the propeller. The propulsion system 10 is attached to the aircraft 2 or the main wing 4. In this embodiment, the propulsion system 10 is attached to the main wing 4.

[0018] The main wing 4 has a wing body member 12 and a control surface member 14. The control surface member 14 is configured separately, corresponding to the left and right wing body members 12. The wing body member 12 is the front portion of the main wing 4 and constitutes at least the leading edge of the wing shape of the main wing 4. The control surface member 14 is the rear portion of the main wing 4 and constitutes at least the trailing edge of the wing shape of the main wing 4. The leading end of the control surface member 14 is connected to the wing body member 12. The control surface member 14 in this embodiment is a so-called "aileron" and is provided so as to be displaceable relative to the wing body member 12. In this embodiment, the control surface member 14 is angularly displaceable about an angular displacement axis AX1 set on the wing body member 12 and extending parallel to the wingspan direction. The aircraft is equipped with a drive device (not shown) that angularly displaces the control surface member 14 relative to the wing body member 12. The drive device can be implemented, for example, using an electric motor. Existing structures can be applied to such a drive device.

[0019] The lift coefficient of the main wing 4 changes as the control surface member 14 undergoes angular displacement relative to the wing body member 12. In other words, the relative position of the trailing edge to the leading edge of the airfoil of the main wing 4 changes. This changes the angle of attack and thus the lift coefficient. The left and right main wings 4 have control surface members 14 that can operate independently or in conjunction with each other. For example, the trailing edge of one main wing 4 can be raised and the trailing edge of the other main wing 4 can be lowered. In this way, by making the lift coefficient of one main wing 4 (for example, the left wing 4L) smaller than that of the other main wing 4 (for example, the right wing 4R), a lift difference is created between the left and right wings 4L and 4R, allowing control of the attitude and steering around the roll axis. Thus, the control surface member 14 of this embodiment constitutes a roll control control surface member that controls the attitude and steering around the roll axis.

[0020] In this embodiment, the angle of the imaginary line connecting the leading edge 12f and the trailing edge 12r of the wing body member 12 with respect to the longitudinal axis LA extending along the aircraft body 2 is the same across the wingtip direction WD. In this embodiment, as shown in Figure 4, the leading edge 12f of the wing body member 12 extends parallel to the wingspan direction WD from the wing root side to the wingtip side in a top view. The leading edge 12f of the wing body member 12 may also be inclined upward from the wing root side to the wingtip side in a front view. The trailing edge 12r of the wing body member 12 extends parallel to the wingspan direction WD from the wing root side to the wingtip side. The imaginary plane including the leading edge 12f and the trailing edge 12r of the wing body member 12 is also a plane that extends parallel to the wingspan direction WD.

[0021] As shown in Figure 4, the wing body member 12 has a wing spar 16, a plurality of ribs 18, and a skin 20. The wing spar 16 is a skeletal member extending in the wingspan direction WD. Each rib 18 is connected to the wing spar 16 and arranged in a line with spacing in the wingspan direction WD, and each has an outer shape that defines the airfoil. The skin 20 covers the plurality of ribs to realize the outer shape of the airfoil. In this embodiment, the wing body member 12 has a uniform airfoil portion along the wingspan direction WD. In other words, there are locations where ribs 18 of the same shape are lined up in the wingspan direction WD. By having at least two ribs 18 of the same shape in this way, the number of types of members required for the main wing construction can be reduced, and the manufacturing work can be simplified. In other words, the number of jigs required for main wing formation can be reduced.

[0022] Thus, the wing body member 12 has a uniform angle of attachment along the wingspan direction WD. The "angle of attachment" is the angle relative to the aircraft when the wing body member 12 is attached to the aircraft 2, and refers to the angle between the line connecting the leading and trailing ends of the wing body member 12 and the line LA1 parallel to the aircraft's longitudinal axis LA (Figure 1). Furthermore, "having a uniform angle of attachment along the wingspan direction WD" means that the angle of attachment of the wing body member 12 is the same from the wing root to the wingtip.

[0023] In this embodiment, during horizontal flight, the wing body member 12 has a uniform external shape across the wingspan direction WD. Furthermore, "having a uniform external shape across the wingspan direction WD" means that the wing body 4 has the same external shape in a cross section perpendicular to the wingspan direction WD from the wing root to the wingtip.

[0024] In this embodiment, the main wing 4 has a wingtip member 22. The wingtip member 22 is connected to the wingtip side of the wing body member 12. The wingtip member 22 includes an inclined portion whose leading edge slopes backward as it progresses toward the wingtip, and a wingtip plate formed at the wingtip of the inclined portion and projecting upward. The wingtip member 22 is optional.

[0025] In this embodiment, the rotor blade member 14 is connected to the wing body member 12 closer to the wing root than the wingtip member 22. As shown in Figure 2, the rotor blade member 14 is formed to be smaller than the wing body member 12. Specifically, the rotor blade member 14 is formed to be smaller in the longitudinal direction than the wing body member 12. In this embodiment, it is formed over the entire wingspan direction WD where the wing body member 12 generates lift. Furthermore, in this embodiment, the shape of the rotor blade member 14 changes along the wingspan direction WD. Specifically, the vertical dimension of the rotor blade member 14 changes as it progresses along the wingspan direction WD.

[0026] In Figures 1 to 3, the change in the wingspan direction WD at the rear end of the rotor blade member 14 is exaggerated to illustrate its shape. This embodiment also includes a structure in which the shape of the rear end of the rotor blade member 14 changes with a smaller amount of change than shown in the illustrated example. The rear end of the rotor blade member 14 may be divided into a portion that is uniform in the wingspan direction WD and a portion that changes in the wingspan direction WD, or it may be a shape that changes continuously over the entire wingspan direction WD of the rotor blade member 14. This prevents stress from concentrating in a part of the rotor blade member 14.

[0027] In an aircraft 2 provided with a wingtip member 22 as in this embodiment, it is preferable that, in a straight-line flight state, the portion of the main wing 4 that is on the wingtip side, outward in the wingspan direction WD from the control surface member 14, is formed to be the same height as the rear end of the control surface member 14. However, the present invention can also be applied to aircraft that do not include a wingtip member 22.

[0028] Figure 5 shows the cross-sectional shape of the main wing 4 at the wing root side, including the control surface member 14, and Figure 6 shows the cross-sectional shape of the main wing 4 at the wingtip side, including the control surface member 14. As shown in Figures 4 to 6, the control surface member 14 has different cross-sectional shapes perpendicular to the wingspan direction WD at the wing root side and the wingtip side. In this embodiment, the cross-sectional shape perpendicular to the wingspan direction WD of the control surface member 14 changes continuously as it moves toward the wingtip side with respect to the wingspan direction WD. As the control surface member 14 moves from the wing root side to the wingtip side, the angle between the imaginary line V12 connecting the leading end 14f and the trailing end 14r and the plane F1 extending in the propulsion direction becomes smaller. However, the cross-sectional shape perpendicular to the wingspan direction WD of the control surface member 14 may change in steps as it moves toward the wingtip side with respect to the wingspan direction WD.

[0029] In the cross-sectional shape of the control surface member 14 perpendicular to the wingspan direction WD, the angle θ2 at the wingtip side is smaller than the angle θ1 at the wing root side with respect to the angle formed by the imaginary line V12 connecting the front end 14f and the rear end 14r and the plane F1 extending in the direction of propulsion. Specifically, the front end 14f of the control surface member 14 extends parallel to the wingspan direction WD from the wing root side to the wingtip side. In contrast, the rear end 14r of the control surface member 14 is inclined upward with respect to the wingspan direction WD as it moves from the wing root side to the wingtip side, or in other words, it is twisted. Thus, in this embodiment, the rear end 14r at the wingtip side of the control surface member 14 is positioned higher than the rear end 14r at the wing root side.

[0030] In this way, by forming the trailing end 14r of the movable blade member 14, the lift coefficient of the main wing 4 becomes smaller at the wingtip side than at the wing root side. In other words, the angle of attack of the main wing 4 becomes smaller at the wingtip side than at the wing root side, even without a change in the wingspan direction of the main wing body member 12. By reducing the lift coefficient at the wingtip side of the main wing 4, the main wing 4 can prevent airflow separation at the wingtip side. This makes it possible to suppress the sharp decrease in lift at the wingtip side caused by airflow separation. This makes it possible to improve the stability of the wingtip around the roll axis. In addition, by reducing the lift coefficient at the wingtip side, air resistance can be reduced and the range can be increased.

[0031] In this embodiment, the rotor blade member 14 has a region on the rotor blade side where the same external shape is formed perpendicular to the wingspan direction WD. This makes it easier to standardize the multiple ribs constituting the rotor blade member 12 compared to when the shape of the rotor blade member 14 changes throughout its entire length from the root to the tip. In addition, in this embodiment, the rotor blade member 14 reduces the lift coefficient at the tip of the main wing 4. The rotor blade member 14 requires less strength than the main wing body member 12, which is struck by airflow, and therefore has a greater degree of structural freedom than the main wing body member 12. Consequently, it is easier to modify its shape to reduce the lift coefficient at the tip of the main wing 4.

[0032] Furthermore, the control surface member 14 is formed to be smaller than the wing body member 12. Specifically, it is formed to be smaller in the front-rear dimension. This makes it easier to simplify the structure by reducing the need for changes in the shape of ribs 18 and other components, thereby lowering the lift coefficient at the wingtip side of the main wing 4. The aircraft of this embodiment is preferably applied to unmanned aerial vehicles. When used in unmanned aerial vehicles, the weight can be reduced compared to manned aircraft, and the tolerance for rigidity and reliability required of the wing can be increased. For this reason, it is easier to lower the lift coefficient at the wingtip side of the main wing 4 by using the shape changes made by the control surface member 14.

[0033] By changing the shape of the control surface member 14, the wing body member 12 can suppress changes in the wingspan direction WD and reduce the lift coefficient at the wingtip. In this way, by suppressing changes in the shape of the wing body member 12, the shapes of the ribs 18 and skin 20 that constitute the wing body member 12 can be simplified. Furthermore, the number of jigs used to form the ribs 18 and skin 20 can be reduced. In this embodiment, in order to suppress changes in the wingspan direction WD, it is preferable that the leading edge 12f of the wing body member 12 extends parallel to the wingspan direction WD when viewed from above. However, the leading edge 12f of the wing body member 12 may be inclined rearward as it approaches the wingtip when viewed from above, or inclined with respect to the wingspan direction WD when viewed from the front. Even in this case, by devising the shape of the control surface member 14, the wing body member 12 can suppress changes in the wingspan direction WD and reduce the lift coefficient at the wingtip.

[0034] In the main wing 4, it is preferable that the region where the damping angle is small is located on the wingtip side of the wing body member 4, rather than on the midpoint M in the wing span direction. In Figures 5 and 6, if the angles of attack of the main wing are θ1 and θ2, respectively, the angle of attack θ2 on the wingtip side is smaller than the angle of attack θ1 on the wing root side (θ2 < θ1). The angles of attack θ1 and θ2 refer to the angle between the line LA1, which is parallel to the longitudinal axis LA, and the chord VL of the main wing 4. Specifically, in this embodiment, the angle between the imaginary line V12 connecting the front end 14f and the rear end 14r of the control surface member 14 and the line LA1, which is parallel to the longitudinal axis LA, is set to be smaller on the wingtip side (Figure 6) than on the wing root side (Figure 5). As a result, for the main wing 4 as a whole, the angle of attack θ2 on the wingtip side is smaller than the angle of attack θ1 on the wing root side (θ2 < θ1).

[0035] Figure 7 shows the wing structure of the second embodiment. The aircraft of the second embodiment is a tailless aircraft without a horizontal stabilizer. In the second embodiment as well, the main wings 4 are connected to both sides of the fuselage 2. In the second embodiment, the propulsion system 10 is provided at the rear end of the fuselage 2.

[0036] In the second embodiment as well, the main wing 4 has a wing body member 12 and a movable blade member 14. The leading edge 12f of the wing body member 12 is inclined rearward as it progresses in the wing span direction WD. The cross-sectional shape of the main wing 4 perpendicular to the wing span direction WD is formed in an airfoil shape.

[0037] The rotor blade members 14 are provided so as to be able to displace relative to the wing body member 12. The left and right pair of rotor blade members 14 can be configured to operate independently of each other. By raising and lowering the rear ends of both rotor blade members 14 together, the lift generated on the main wing 4 can be changed.

[0038] By raising the trailing edge of one main wing 4 (for example, the left wing 4L) and lowering the trailing edge of the other main wing 4 (for example, the right wing 4R), it is used to control the attitude and steering of the aircraft around the roll axis. Thus, the control surface member 14 of the second embodiment has both the function of controlling the attitude and steering around the roll axis and the function of adjusting the lift. The control surface member 14 is sometimes called an elevon.

[0039] The main wing 4 may extend parallel to the longitudinal axis LA of the aircraft 2. In this case, by propelling the aircraft 2 with its longitudinal axis LA tilted, an angle of attack can be applied to the main wing 4, thereby generating lift.

[0040] The main wing 4 is formed with the same shape in the longitudinal direction along the wingspan direction WD. In other words, the dimensions between the leading edge and the trailing edge are uniform. The wing body member 12 that constitutes the leading portion of the main wing 4 is formed with a uniform shape or a shape with little variation along the wingspan direction WD.

[0041] In the second embodiment as well, the shape of the control surface member 14 changes as it progresses in the wing span direction WD. The trailing end 14r of the control surface member 14 is positioned higher towards the wingtip than towards the wing root. The control surface member 14 changes so that its longitudinal dimension increases towards the wingtip in the wingtip width direction WD. This makes it possible to reduce the angle of attack of the wingtip side of the main wing 4, in other words, the lift coefficient.

[0042] Figures 8 and 9 are cross-sectional views along lines VIII-VIII and IX-IX in Figure 7, respectively. In Figures 8 and 9, if the angles of attack of the main wing 4 are θ4 and θ5, respectively, the angle of attack θ5 at the wingtip is smaller than the angle of attack θ4 at the wing root (θ5 < θ4). Specifically, in this embodiment, the angle θ3 of the movable blade member 14 is constant between the imaginary line V12 connecting the front end 14f and the rear end 14r and the line LA1 parallel to the longitudinal axis LA, but the length in the longitudinal direction is different. That is, although the angle θ3 is the same at the wing root (Figure 8) and the wingtip (Figure 9), the length of the movable blade member 14 in the longitudinal direction is set to be larger at the wingtip (Figure 9) than at the wing root (Figure 8). As a result, for the main wing 4 as a whole, the angle of attack θ5 at the wingtip is smaller than the angle of attack θ4 at the wing root (θ5 < θ4).

[0043] According to the second embodiment, the front-rear dimension L1 of the tip-side portion of the moving blade member 14 is larger than the front-rear dimension L2 of the root-side portion. As a result, due to the difference in the angle of attack, the lift coefficient becomes smaller toward the tip-side portion, so that the separation of the airflow at the tip side can be prevented. Also, similar to the first embodiment, the structure of the wing body member 12 can be easily simplified. Further, in the second embodiment, for the purpose of reducing the lift coefficient on the tip side of the main wing 4, it is not necessary to make the moving blade member 12 have a complicated shape, and it is easy to simplify the structure.

[0044] As the propulsion device 10, a propulsion device such as a jet engine other than a propeller may be used. The present structure may be applied not only to unmanned aircraft but also to manned aircraft.

[0045] The leading edge of the main wing 4 may extend parallel to the wing width direction WD from the root side toward the tip side in a front view. Also, the leading edge of the main wing 4 may be inclined downward from the root side toward the tip side in a front view. Further, the leading edge of the main wing 4 may be formed so as to be inclined rearward from the root side toward the tip side in a top view.

[0046] In the above embodiment, one type of moving blade member 14 with a reduced lift coefficient on the tip side was provided at the rear of the wing body member 12, but it is not limited to this. For example, a plurality of types of moving blade members 14 that can be relatively displaced may be formed with respect to the wing body member 12. Even in this case, among the plurality of moving blade members 14, it is sufficient that at least one moving blade member 14 forms the tip-side portion of the main wing 4 to have a smaller lift coefficient than the root-side portion. When a plurality of moving blade members 14 are provided with respect to the rear portion of one wing body member 12, it is preferable that among the plurality of moving blade members 14, the lift coefficient of the tip-side portion is made smaller by the tip-side moving blade member 14.

[0047] For example, an aircraft may be provided with an aileron, which is a movable wing that controls the attitude and steering around the roll axis, and a flap, which is a movable wing that adjusts lift, separately. In this case, the aileron may be formed such that the lift coefficient at the wing tip side of the main wing 4 becomes smaller. Also, both the aileron and the flap may be formed such that the lift coefficient at the wing tip side of the main wing 4 becomes smaller. Further, a movable wing member 14 having the functions of the aileron and the flap may be formed such that the lift coefficient at the wing tip side of the main wing 4 becomes smaller.

[0048] Also, in the above embodiment, among the movable wing members 14, the rear end portion on the wing tip side is configured to be at a higher position than the rear end portion on the wing root side, but the present invention is not limited to this. That is, it is sufficient that the movable wing member 14 has a function such that the lift coefficient at the wing tip side of the main wing 4 becomes smaller. For example, regarding the movable wing member 14, the front-rear dimension of the rear end, the upper surface shape, the lower surface shape, the center line, the maximum wing thickness position, the maximum camber position, etc. may be made different between the wing tip side and the base end side of the movable wing member 14 to reduce the lift coefficient at the wing tip side of the main wing 4.

[0049] The present disclosure is not limited to the above forms, and various additions, changes, or deletions are possible without departing from the gist of the present disclosure. Therefore, such things are also included within the scope of the present disclosure.

[0050] 2 Airframe 4 Main wing 12 Wing body member 14 Movable wing member

Claims

1. An unmanned aircraft comprising: an airframe; a pair of left and right wing body members connected to the airframe at the wing root and extending in the wingspan direction toward the wingtip; and a main wing having at least one movable wing member provided on the trailing edge of the wing body members and being displaceable relative to the wing body members, wherein the at least one movable wing member has a wing root portion located toward the wing root and a wingtip portion located toward the wingtip, and the wingtip portion has a smaller lift coefficient than the wing root portion.

2. An unmanned aerial vehicle according to claim 1, wherein the wing body member has the same angle across the wingspan direction as the imaginary line connecting the front end and the rear end with respect to the longitudinal axis extending along the aircraft body.

3. An unmanned aerial vehicle according to claim 1 or 2, wherein the angle between the imaginary line connecting the leading end and the trailing end and the plane extending in the direction of propulsion decreases as the at least one movable wing member progresses from the wing root side to the wingtip side.

4. An unmanned aerial vehicle according to any one of claims 1 to 3, wherein the leading edge of the wing body member extends parallel to the wing span direction from the wing root side to the wingtip side.

5. An unmanned aircraft according to any one of claims 1 to 4, wherein at least one control surface member has a roll control surface member that has a function of controlling the attitude of the aircraft around the roll axis, and the roll control surface member is formed to have a small lift coefficient at the wingtip side portion.

6. An unmanned aircraft according to claim 5, wherein the main wing has other control surface members, separate from the at least one control surface member, that have a function to control aircraft behavior different from the attitude of the aircraft around the roll axis, and the other control surface is formed in a uniform shape over the wingspan.

7. An unmanned aerial vehicle according to any one of claims 1 to 6, wherein the upper end position of the wingtip portion of at least one movable wing member is located above the upper end position of the wing root portion.

8. An unmanned aerial vehicle according to any one of claims 1 to 7, wherein the longitudinal dimension of the wingtip portion of at least one movable wing member is greater than the longitudinal dimension of the wing root portion.

9. An aircraft wing structure comprising: a wing body member connected to the airframe at the wing root and extending in the wingspan direction toward the wingtip; and at least one movable surface member provided on the trailing edge of the wing body member and capable of relative displacement with respect to the wing body member, wherein the trailing end of the at least one movable surface member is positioned higher than the trailing end of the base.

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