aircraft

Abstract

When the aircraft (10) is viewed from the main view, there is an overlapping portion (66) where at least a portion of the fuselage (12) and at least a portion of the two cruise rotors (22) overlap. The rear part (12r) of the fuselage (12) has an inclined surface (68) which is displaced from top to bottom as it moves from front to rear, such that the area of ​​the overlapping portion (66) gradually decreases as it moves from front to rear.

Description

Technical Field

[0001] This invention relates to an aircraft capable of taking off and landing and cruising in the vertical direction. Background Technology

[0002] U.S. Patent Application Publication No. 2020 / 0115045 discloses an aircraft referred to as a vertical takeoff and landing (VTOL) aircraft. The aircraft shown in U.S. Patent Application Publication No. 2020 / 0115045 has a fuselage, a canard and a tail (main wing) connected to the fuselage, multiple takeoff and landing rotors configured on the left and right sides of the fuselage, and multiple cruise rotors configured above the tail. The aircraft uses the takeoff and landing rotors during takeoff and landing and when stationary, and uses the cruise rotors during cruise. Furthermore, the aircraft uses both the takeoff and landing rotors and the cruise rotors during transitions from stationary to cruise flight and from cruise flight to stationary flight. Summary of the Invention

[0003] When a thrust device is positioned on the upper part of the wing, aerodynamic design disadvantages arise. Therefore, it is preferable to position the thrust device on the lower part of the wing. However, in the aircraft described in U.S. Patent Application Publication No. 2020 / 0115045, it is assumed that if the thrust device is positioned on the lower part of the tail, the following problems are concerned.

[0004] In the aircraft described in U.S. Patent Application Publication No. 2020 / 0115045, a takeoff and landing rotor is positioned in front of the cruise rotor when viewed from above. The pair of takeoff and landing rotors positioned in front of the cruise rotor direct airflow downwards. This generated airflow interferes with the air directed towards the cruise rotor from the front. Consequently, the airflow directed towards the cruise rotor generates turbulence, raising concerns that this may affect the thrust generated by the cruise rotor.

[0005] On the other hand, when the cruise rotor is positioned to the side of the fuselage, the fuselage is located in front of the cruise rotor. Therefore, there is a concern that the fuselage might obstruct the airflow directed to the cruise rotor. In this situation, it could result in insufficient utilization of the thrust generated by the cruise rotor.

[0006] In view of the above-mentioned technical problems, the object of the present invention is to provide an aircraft that can fully obtain the thrust generated by the cruise rotor.

[0007] The present invention relates to an aircraft having a fuselage, wings, and two or more cruise rotors, wherein,

[0008] The wing is connected to the upper rear part of the fuselage;

[0009] Two or more cruise rotors are respectively positioned to the right and left of the fuselage's central axis, configured to generate thrust during horizontal movement.

[0010] When the aircraft is viewed from the main viewpoint, there is an overlapping portion where at least a portion of the fuselage and at least a portion of the two cruise rotors coincide.

[0011] The rear portion of the fuselage has an inclined surface, which is displaced from top to bottom as it moves from front to rear, such that the area of ​​the overlapping portion gradually decreases as it moves from front to rear.

[0012] According to the present invention, the thrust generated by the cruise rotor can be fully obtained. Attached Figure Description

[0013] Figure 1 This is a perspective view of the aircraft involved in this embodiment.

[0014] Figure 2 This is a top view of the aircraft involved in this embodiment.

[0015] Figure 3 This is a left view of the aircraft involved in this embodiment.

[0016] Figure 4 This is a front view of the aircraft involved in this embodiment.

[0017] Figure 5 This is a rear view of the aircraft involved in this embodiment.

[0018] Figure 6 This is a three-dimensional view of the rear perimeter of the fuselage viewed from an oblique angle.

[0019] Figure 7 This is a 3D view of the rear perimeter of the fuselage viewed from a slightly lower angle. Detailed Implementation

[0020] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0021] [1. Overall structure of aircraft 10]

[0022] In this embodiment, the aircraft 10 is envisioned as an electric vertical takeoff and landing (eVTOL) aircraft, which generates lift and thrust through a rotor equipped with an electric motor. Furthermore, in this specification, vertically upward is defined as the upward direction (above), and vertically downward is defined as the downward direction (below). Additionally, the direction of movement when the aircraft 10 moves horizontally (flight) is defined as the forward direction (forward), and the opposite direction of the forward direction is defined as the rearward direction (rear). Furthermore, when the aircraft 10 is facing forward, the direction to the right of the aircraft 10 in its width direction is defined as the right direction (right side), and the direction to the left of the aircraft 10 in its width direction is defined as the left direction (left side). The view of each part from directly above the aircraft 10 is referred to as a top-down view of the aircraft 10. The view of each part from the front of the aircraft 10 is referred to as a frontal view (direct view) of the aircraft 10.

[0023] Aircraft 10 has a fuselage 12, canard 14, tail 16, two cantilevers 18, eight takeoff and landing rotors 20, and two cruise rotors 22. (The last part is a repetition of the first part and can be omitted.) Figure 2 As shown, the structure of aircraft 10 is symmetrical about its center when viewed from above, with the center axis A of the fuselage 12 extending in the longitudinal direction as the center. When viewed from above, the center axis A coincides with the center of gravity G of aircraft 10.

[0024] The fuselage 12 is long in the longitudinal direction. The fuselage 12 has a front portion 12f and a rear portion 12r. The front portion 12f is located forward of the center of gravity G; the rear portion 12r is located rearward of the center of gravity G. The front portion 12f is tapered at the front end. The rear portion 12r is tapered at the rear end. Additionally, the main body of the fuselage 12 may be partially covered by a fairing. In the specification, including the fairing, the components are referred to as fuselage 12, front portion 12f, and rear portion 12r.

[0025] The canard 14 is configured to be connected to the upper part of the front 12f of the fuselage 12 and generates lift when the aircraft 10 moves forward. The canard 14 has a canard body (also called a horizontal stabilizer) 26 extending from the center to the left and right and elevators 28 located on the left and right trailing edges of the canard 14.

[0026] The tail 16 is configured to be connected to the upper part of the rear 12r of the fuselage 12 via a pylon 32, generating lift when the aircraft 10 moves forward. The tail 16 has: a tail body 34 extending from the center to the left and right rear; left and right elevons 36 disposed on the trailing edge of the tail 16; and a pair of vertical tails 38 disposed on the left and right wingtips of the tail 16. Each vertical tail 38 has a tail body 42 (also called a vertical stabilizer) and a rudder 44 disposed on the trailing edge of the vertical tail 38.

[0027] The tail fin 16 has a larger wing area than the canard fin 14. Furthermore, the tail fin 16 has a wider wing width than the canard fin 14. Due to this configuration, the tail fin 16 generates more lift than the canard fin 14 when the aircraft 10 moves forward. In other words, the tail fin 16 functions as the main wing of the aircraft 10. The tail fin 16 is a swept wing that reduces air resistance. On the other hand, the canard fin 14 functions as the leading wing of the aircraft 10. Both the canard fin 14 and the tail fin 16 function as support components for the two cantilever arms 18.

[0028] Furthermore, the lift generated by the tail 16 when the aircraft 10 moves forward and the lift generated by the canard 14 when the aircraft 10 moves forward can be of the same magnitude. The relationship between the magnitudes of the lift generated by the canard 14 and the lift generated by the tail 16 is appropriately determined based on the position of the center of gravity G, the attitude of the aircraft during cruise, etc. In addition, the sizes (wing area, length, etc.) of the canard 14 and the tail 16 are determined to generate the desired lift.

[0029] The two cantilever arms 18 consist of a right cantilever arm 18 positioned to the right of the fuselage 12 and a left cantilever arm 18 positioned to the left of the fuselage 12. The two cantilever arms 18 form a pair, symmetrically arranged around a point overlapping the central axis A of the fuselage 12 when viewed from above. The two cantilever arms 18 function as support components for the takeoff and landing rotor 20.

[0030] The right cantilever 18 is a rod component that extends from front to rear and curves to the right (outward in the width direction) in an arc shape. The right cantilever 18 connects to the right wingtip of the canard 14 and is located inside the elevon 36 of the right wing of the tail 16. The front end of the right cantilever 18 is positioned forward of the canard 14. The rear end of the right cantilever 18 is positioned rearward of the tail 16.

[0031] The left cantilever 18 is a rod component that extends from front to rear and curves to the left (outward in the width direction) in an arc shape. The left cantilever 18 connects to the left wingtip of the canard 14 and is located inside the elevon 36 of the left wing of the tail 16. The front end of the left cantilever 18 is positioned forward of the canard 14. The rear end of the left cantilever 18 is positioned rearward of the tail 16.

[0032] The takeoff and landing rotor 20 has a rotating mast (not shown) connected to the output shaft of an electric motor (not shown) and a propeller 46 mounted on the rotating mast. The rotating mast is configured parallel to the vertical direction and can rotate about an axis extending in the vertical direction. The propeller 46 is located above the cantilever 18, the canard 14, and the tail fin 16. With this configuration, the propeller 46 can rotate about an axis extending in the vertical direction. Each takeoff and landing rotor 20 generates lift through the rotation of the propeller 46.

[0033] The eight takeoff and landing rotors 20 consist of four rotors 20a-20d positioned to the right of the fuselage 12 and four rotors 20a-20d positioned to the left of the fuselage 12. The right-side rotors 20a-20d are supported by a right-side cantilever 18. The left-side rotors 20a-20d are supported by a left-side cantilever 18. The right-side and left-side rotors 20a-20d, positioned in the same longitudinal direction, form a pair.

[0034] like Figure 2 As shown, when viewed from above, from front to rear, the following components are arranged sequentially: a pair of takeoff and landing rotors 20a, a canard 14, a pair of takeoff and landing rotors 20b, a pair of takeoff and landing rotors 20c, a tail fin 16, and a pair of takeoff and landing rotors 20d. Specifically, the pair of takeoff and landing rotors 20a is positioned forward of the canard fin 14. Furthermore, the pair of takeoff and landing rotors 20b is positioned between the canard fin 14 and the tail fin 16, and is positioned forward of the pair of takeoff and landing rotors 20c. Additionally, the pair of takeoff and landing rotors 20c is positioned between the canard fin 14 and the tail fin 16, and is positioned rearward of the pair of takeoff and landing rotors 20b. Finally, the pair of takeoff and landing rotors 20d is positioned rearward of the tail fin 16.

[0035] Two cruise rotors 22 are configured at the rear 12r of the fuselage 12. The cruise rotors 22 are positioned laterally (on the fuselage 12 side) than the pairs of takeoff and landing rotors 20. Furthermore, the cruise rotors 22 are positioned longitudinally between the pair of takeoff and landing rotors 20c and 20d. Additionally, the shaft of the cruise rotors 22 is positioned vertically below the propellers 46 of the takeoff and landing rotors 20.

[0036] like Figures 5-7As shown, the cruise rotor 22 has a rotating mast (not shown) connected to the output shaft of an electric motor (not shown), a propeller 52 mounted on the front end of the rotating mast, and a cylindrical duct 54 surrounding the propeller 52. The two cruise rotors 22 are positioned in the same longitudinal and vertical directions. Furthermore, the two cruise rotors 22 are arranged side-by-side. One cruise rotor 22 is positioned to the right of the point where it overlaps with the central axis A of the fuselage 12 in a top-view view, and is supported by the right wing of the tail 16. The other cruise rotor 22 is positioned to the left of the point where it overlaps with the central axis A of the fuselage 12 in a top-view view, and is supported by the left wing of the tail 16. The rotating mast is positioned below the tail 16 in a manner parallel to the longitudinal direction and is capable of rotating about an axis extending in the longitudinal direction. With this configuration, the propeller 52 can rotate about an axis extending in the longitudinal direction. Each cruise rotor 22 generates thrust through the rotation of the propeller 52.

[0037] The duct 54 has an outer cylindrical portion 56, a central portion 58 on the central side, and a plurality of (three in this embodiment) arms 60 extending radially along the duct 54 between the inner circumferential surface of the cylindrical portion 56 and the outer circumferential surface of the central portion 58. The outer circumferential surfaces of the left and right cylindrical portions 56 are connected to each other. The cylindrical portion 56 is cylindrical, centered on the rotating mast, and surrounds the propeller 52. A recess 62 is formed on the rear side of the tail fin 16 and between the left and right elliptical ailerons 36 and the left and right cantilever arms 18, extending in the forward-backward, left-right, and up-down directions. The cylindrical portion 56 of the duct 54 is disposed inside the recess 62. However, the cylindrical portion 56 and the recess 62 are separate from each other. Figure 7 As shown, downwardly projecting protrusions 64 are formed on the lower parts of the left and right wings of the tail fin 16. The central portion 58 of the duct 54 is connected to the protrusions 64.

[0038] like Figure 4 As shown, in frontal view, a portion of the tail fin 16 overlaps with a portion of the cruise rotor 22. Furthermore, in frontal view, the upper part of the cruise rotor 22 protrudes upwards beyond the tail fin 16, while the center and lower part of the cruise rotor 22 protrude downwards beyond the tail fin 16.

[0039] Here, the positional relationship between the rear part 12r of the fuselage 12 and the cruise rotor 22 will be explained. For example... Figure 4 As shown, in a frontal view, at least a portion of the fuselage 12 and at least a portion of the two cruise rotors 22 overlap each other. Thus, the portion in which the fuselage 12 and the two cruise rotors 22 overlap each other in a frontal view is referred to as the overlapping portion 66.

[0040] like Figure 6 , Figure 7As shown, the rear portion 12r has an inclined surface 68, which is displaced from top to bottom as it moves from front to rear, with the overlapping area 66 gradually decreasing as it moves from front to rear. The inclined surface 68 extends from front to rear and from top to bottom. The inclined surface 68 is formed on the upper right and upper left parts of the rear portion 12r, centered on the pylon 32. The inclined surface 68 guides a portion of the air flowing from front to rear above the fuselage 12 toward the cruise rotor 22.

[0041] The inclined surface 68 can be a plane or a curved surface. For example, in a cross-section parallel to the front-back and up-down directions, the inclined surface 68 can be straight or curved downwards. Similarly, in a cross-section parallel to the left-right and up-down directions, the inclined surface 68 can be straight or curved downwards. Furthermore, when the inclined surface 68 is curved, in a cross-section parallel to the left-right and up-down directions, the outer peripheral surface of the hanger 32 and the inclined surface 68 are preferably in a continuous curved shape.

[0042] The rear end 70 of the inclined surface 68 is positioned lower in the vertical direction than the cruise rotor 22. Alternatively, the rear end 70 of the inclined surface 68 is preferably positioned rearward or at the same position as the cruise rotor 22 in the longitudinal direction. However, the rear end 70 of the inclined surface 68 may also be positioned forward of the cruise rotor 22 in the longitudinal direction. With this configuration, an unobstructed space is formed directly in front of the duct 54.

[0043] like Figure 3 , Figures 5-7 As shown, in this embodiment, the lower surface of the rear portion 12r of the fuselage 12 moves upward from bottom to top as it moves from front to rear. Therefore, the cross-sectional area of ​​the rear portion 12r of the fuselage 12, which is parallel to the left-right and up-down directions, gradually decreases as it moves from front to rear. However, the lower surface of the rear portion 12r can move downward from top to bottom along with the inclined surface 68 as it moves from front to rear, or it can extend horizontally from front to rear.

[0044] [2. Relationship between flight status and the rotor used]

[0045] The takeoff and landing rotor 20 is used during takeoff, landing, and stationary flight of the aircraft 10. On the other hand, the cruise rotor 22 is used during cruise flight of the aircraft 10. Furthermore, the takeoff and landing rotor 20 and the cruise rotor 22 are used together when the aircraft 10 transitions from stationary flight to cruise flight, i.e., when moving forward at a speed greater than or equal to a first speed (≥0 km / h) and less than a second speed (>1 speed). In this case, the utilization rate of the cruise rotor 22 gradually increases to accelerate. With acceleration, the lift generated by the wing increases, thus gradually decreasing the utilization rate of the takeoff and landing rotor 20. For example, the utilization rate of the takeoff and landing rotor 20 can be reduced by decreasing its rotational speed to decrease lift. Alternatively, the utilization rate of the takeoff and landing rotor 20 can be reduced by changing the pitch angle of each blade to decrease lift.

[0046] Furthermore, the takeoff and landing rotor 20 and the cruise rotor 22 are used in conjunction when the aircraft 10 transitions from cruise flight to stationary flight, i.e., when moving forward at a speed greater than or equal to the third speed (≥0 km / h) and less than the fourth speed (> the third speed). In this case, the utilization rate of the cruise rotor 22 gradually decreases in order to decelerate. With deceleration, the lift generated by the wings decreases, thus the utilization rate of the takeoff and landing rotor 20 gradually increases. For example, the utilization rate of the takeoff and landing rotor 20 can be increased by increasing its rotational speed to increase lift. Alternatively, the utilization rate of the takeoff and landing rotor 20 can be increased by changing the pitch angle of each blade to increase lift.

[0047] [3 Technical ideas that can be obtained from the implementation method]

[0048] The following describes the technical concepts that can be grasped based on the above implementation methods.

[0049] The present invention relates to an aircraft 10 having a fuselage 12, wings (tail 16) and two or more cruise rotors 22, wherein,

[0050] The wing is connected to the upper part of the rear part 12r of the fuselage 12;

[0051] Two or more cruise rotors 22 are respectively positioned to the right and left of the central axis A of the fuselage 12, configured to generate thrust during horizontal movement.

[0052] When the aircraft 10 is viewed from the main viewpoint, there is an overlapping portion 66 where at least a portion of the fuselage 12 and at least a portion of the two cruise rotors 22 overlap.

[0053] The rear portion 12r of the fuselage 12 has an inclined surface 68, which is displaced from top to bottom as it moves from front to rear, such that the area of ​​the overlapping portion 66 gradually decreases as it moves from front to rear.

[0054] In the above structure, when viewed from the front, the fuselage 12 and the two cruise rotors 22 overlap. That is, the two cruise rotors 22 are close to the fuselage 12. Furthermore, in this structure, an inclined surface 68 is formed at the rear 12r of the fuselage 12. This inclined surface 68 creates a space directly in front of the cruise rotors 22, thus the rear 12r of the fuselage 12 no longer obstructs the flow of air guided to the cruise rotors 22. Moreover, this inclined surface 68 smoothly guides the air flowing from front to rear around the upper periphery of the fuselage 12 towards the cruise rotors 22. Therefore, the air is adequately guided to the cruise rotors 22, thus maximizing the thrust generated by the cruise rotors 22.

[0055] In the embodiments of the present invention, it can be that:

[0056] The rear portion 12r of the fuselage 12 extends to a position below the two cruise rotors 22.

[0057] Based on the above structure, airflow from the front can be guided to the cruise rotor 22. Therefore, thrust can be generated efficiently.

[0058] In the embodiments of the present invention, it can be that:

[0059] The cross-sectional area of ​​the rear portion 12r of the fuselage 12, which is parallel to the left-right and up-down directions, gradually decreases from the front to the rear.

[0060] Based on the above structure, the shape of the fuselage 12 can guide the airflow from the front to the cruise rotor 22. Therefore, thrust can be generated efficiently.

[0061] In the embodiments of the present invention, it is also possible to:

[0062] The two cruise rotors 22 are connected to the wing (tail 16).

[0063] When the aircraft 10 is viewed from the main viewpoint, at least a portion of the wing coincides with at least a portion of the two cruise rotors 22.

[0064] The center of each of the cruise rotors 22 is located below the wing.

[0065] According to the above structure, the portion of the cruise rotor 22 that protrudes upwards from the wing (tail 16) is smaller than the portion of the cruise rotor 22 that protrudes downwards from the wing, thus reducing the drag generated by the cruise rotor 22.

[0066] In the embodiments of the present invention, it is also possible to:

[0067] The two cruise rotors 22 each have a propeller 52 and a duct 54 surrounding the propeller 52.

[0068] The ducts 54 of the two cruise rotors 22 are interconnected.

[0069] According to the above structure, one cruise rotor 22 is connected to the wing (tail 16) and the other cruise rotor 22, thus increasing the rigidity of the cruise rotor 22 and the wing.

[0070] In the embodiments of the present invention, it can be that:

[0071] It has multiple take-off and landing rotors 20, and the multiple take-off and landing rotors 20 are configured to generate lift.

[0072] At least a portion (takeoff and landing rotor 20d) of the plurality of said takeoff and landing rotors 20 is positioned further rearward than two or more said cruise rotors 22.

[0073] According to the above structure, the airflow generated by the takeoff and landing rotor 20d, which is positioned behind the cruise rotor 22, does not interfere with the airflow guided to the cruise rotor 22. Therefore, it will not adversely affect the thrust generated by the cruise rotor 22.

[0074] In the embodiments of the present invention, it can be that:

[0075] The wing (tail 16) has flight control surfaces (elephants 36) on the right and left wings respectively.

[0076] The two cruise rotors 22 are positioned on the side of the fuselage 12 relative to the left and right flight control surfaces.

[0077] Furthermore, the aircraft involved in this invention are not limited to the aforementioned embodiments, and various structures can certainly be adopted without departing from the spirit of this invention.

Claims

1. An aircraft (10) having a fuselage (12), wings (16) and two or more cruise rotors (22), wherein, The wing (16) is connected to the upper part of the rear part (12r) of the fuselage; Two or more of the aforementioned cruise rotors (22) are respectively positioned to the right and to the left of the fuselage's central axis (A), configured to generate thrust during horizontal movement. Its features are, The two cruise rotors are supported by the wing at a position behind the wing. When the aircraft is viewed from the main viewpoint, at least a portion of the wing coincides with at least a portion of the two cruise rotors. The cruise rotor is positioned directly behind the wing. When the aircraft is viewed from the main viewpoint, there is an overlapping portion (66) where at least a portion of the fuselage and at least a portion of the two cruise rotors overlap. The rear portion of the fuselage has an inclined surface (68) that is displaced from top to bottom as it moves from front to rear, such that the area of ​​the overlapping portion gradually decreases as it moves from front to rear.

2. The aircraft according to claim 1, characterized in that, The rear portion of the fuselage extends below the two cruise rotors.

3. The aircraft according to claim 1 or 2, characterized in that, The cross-sectional area of ​​the rear portion of the fuselage, which is parallel to the left-right and up-down directions, gradually decreases from the front to the rear.

4. The aircraft according to claim 1 or 2, characterized in that, When the aircraft is viewed from the main viewpoint, at least a portion of the wing coincides with at least a portion of the two cruise rotors. The center of each of the cruise rotors is located below the wing.

5. The aircraft according to claim 1 or 2, characterized in that, The two cruise rotors each have a propeller (52) and a duct (54) surrounding the propeller, and the ducts of the two cruise rotors are interconnected.

6. The aircraft according to claim 1 or 2, characterized in that, It has multiple take-off and landing rotors (20), which are configured to generate lift. At least a portion (20d) of the plurality of said take-off and landing rotors is positioned further rearward than two or more said cruise rotors.

7. The aircraft according to claim 1 or 2, characterized in that, The wing has flight control surfaces (36) on the right and left wings respectively. The two cruise rotors are positioned closer to the fuselage side than the left and right flight control surfaces.

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