Flight vehicle

Abstract

To provide a flight vehicle that can reduce influence of wind in a predetermined direction hitting a frame, when flying, so as to improve fuel economy and stability.SOLUTION: A flight vehicle according to the present invention comprises a flight unit including a frame connected with a plurality of rotary wings including at least propellers and motors. The frame has at least two or more kinds of cross sectional shapes according to positions thereof. The frame includes a right frame and a left frame extending in parallel in a longitudinal direction of a fuselage. At least either of the right frame and the left frame has a nearly airfoil-shape portion whose front edge is positioned at outside of the fuselage and whose rear edge is positioned at inside of the fuselage with respect to a perpendicular center line in the frame. The nearly airfoil-shape is an object airfoil-shape.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an air vehicle. [Background technology]

[0002] In recent years, research and demonstration experiments have been conducted to commercialize services using drones, unmanned aerial vehicles (UAVs), and other flying objects (hereinafter referred to as "flying objects"). For practical use, improvements in flight range, payload size and weight, and stability are required.

[0003] Unlike hobby or photography applications, when used to transport luggage or people, aircraft often fly in a fixed direction for long periods of time. Many aircraft on the market, consisting of cylindrical pipes arranged radially as shown in Figure 33 (hereinafter referred to as "existing aircraft"), do not take into consideration the relative wind, making it difficult to improve flight efficiency.

[0004] Patent Document 1 discloses an aircraft having a shape that improves fuel efficiency when the aircraft is cruising in a nose direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 0001995 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent document 1 discloses an aircraft capable of carrying cargo that is provided with a wing-shaped main body, which reduces drag against relative winds from ahead of the aircraft, and generates lift in the main body due to relative winds from the nose direction during flight, thereby improving the fuel efficiency of the aircraft.

[0007] This will enable the aircraft to fly for longer periods of time than existing aircraft, which will make it possible to expand the scope of services such as home delivery and reduce the aircraft's fuel consumption.

[0008] However, the aircraft shape disclosed in Patent Document 1 only takes into consideration the case where the aircraft receives wind from the front. When an aircraft flies outdoors, it is subjected to various winds, such as wind received as the aircraft moves forward, wind from the side of the aircraft due to environmental wind, and wind generated by the aircraft's own propeller.

[0009] Aircraft that do not take into consideration the reduction of drag against various winds and rectification of wind flow cannot be said to have sufficient improvements in fuel efficiency and stability when flying outdoors.

[0010] Therefore, one object of the present invention is to provide an aircraft that can further improve fuel efficiency and stability during cruising by optimizing the frame shape for relative winds from a specified direction. [Means for solving the problem]

[0011] According to the present invention, it is possible to provide an aircraft having a flying section including a frame to which a plurality of rotors, each including at least a propeller and a motor, are connected, wherein the frame has at least two or more cross-sectional shapes depending on its position. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an aircraft that reduces the influence of wind from a predetermined direction hitting the frame during flight, thereby improving fuel efficiency and stability. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a conceptual diagram of an aircraft according to the present invention seen from above. [Figure 2] FIG. 2 is another top view of the flying vehicle of FIG. [Figure 3] FIG. 2 is a side view of the aircraft of FIG. 1. [Figure 4] FIG. 2 is a side view of the aircraft of FIG. 1 during cruising. [Figure 5] FIG. 2 is a front view of the aircraft of FIG. 1. [Figure 6] FIG. 2 is a functional block diagram of the aircraft of FIG. 1. [Figure 7] FIG. 2 is a cross-sectional view of the aircraft taken along line AA′ of FIG. 1. [Figure 8] FIG. 2 is a BB′ cross-sectional view of the aircraft of FIG. 1. [Figure 9] FIG. 10 is a conceptual diagram of another flying vehicle according to the present invention, seen from above. [Figure 10] FIG. 10 is another top view of the flying vehicle of FIG. 9. [Figure 11] FIG. 10 is a side view of the aircraft of FIG. 9. [Figure 12] FIG. 10 is a side view of the aircraft in FIG. 9 during cruising. [Figure 13] FIG. 10 is a front view of the aircraft of FIG. 9. [Figure 14] FIG. 10 is a cross-sectional view of the aircraft taken along line AA′ of FIG. 9. [Figure 15] FIG. 10 is a BB′ cross-sectional view of the aircraft of FIG. 9. [Figure 16] 1 is an example of a cross-sectional shape of a frame. [Figure 17] 10 is an example of the cross-sectional shape of the left and right frames in a push-type rotary wing unit. [Figure 18] 10 is an example of the cross-sectional shape of the left and right frames in a pull-type rotor section. [Figure 19] FIG. 10 is a conceptual diagram of another flying vehicle according to the present invention, seen from above. [Figure 20] FIG. 20 is another top view of the flying vehicle of FIG. 19. [Figure 21] FIG. 20 is a side view of the aircraft of FIG. 19. [Figure 22] FIG. 20 is a side view of the aircraft of FIG. 19 during cruising. [Figure 23] FIG. 20 is a front view of the aircraft of FIG. 19. [Figure 24] 1 is an example of a cross-sectional shape of a frame. [Figure 25] FIG. 10 is a conceptual diagram of another flying vehicle according to the present invention, seen from above. [Figure 26] FIG. 20 is another top view of the flying vehicle of FIG. 19. [Figure 27] FIG. 20 is a side view of the aircraft of FIG. 19. [Figure 28] FIG. 20 is a side view of the aircraft of FIG. 19 during cruising. [Figure 29] FIG. 20 is a front view of the aircraft of FIG. 19. [Figure 30] FIG. 20 is a cross-sectional view of the aircraft taken along line AA′ of FIG. 19. [Figure 31] FIG. 20 is a BB′ cross-sectional view of the aircraft of FIG. 19. [Figure 32] FIG. 10 is a conceptual diagram of another flying vehicle according to the present invention, seen from above. [Figure 33] This is a conceptual diagram of the existing aircraft seen from above. DETAILED DESCRIPTION OF THE INVENTION

[0014] The details of the embodiments of the present invention will be described below. An aircraft according to an embodiment of the present invention has the following configuration. [Item 1] An aircraft having a flying unit including a frame to which a plurality of rotors, each including at least a propeller and a motor, are connected, The frame has at least two or more cross-sectional shapes depending on its position. A flying vehicle characterized by: [Item 2] the frame includes a right frame and a left frame extending side by side in the fore-and-aft direction of the airframe, At least one of the right frame and the left frame has a generally airfoil-shaped portion with a leading edge located on the outer side of the fuselage and a trailing edge located on the inner side of the fuselage with respect to a vertical center line of the frame. 2. The aircraft described in item 1. [Item 3] The approximately airfoil shape is a target airfoil shape, 3. The aircraft described in item 2. [Item 4] the frame includes a right frame and a left frame extending side by side in the fore-and-aft direction of the airframe, In at least one of the right frame and the left frame, at least a frame portion located under the rotation radius of the pull-type rotor has a substantially airfoil-shaped portion inclined in a direction corresponding to the rotation direction of the propeller, and in other frame portions, the substantially airfoil-shaped portion has a leading edge located above the fuselage and a trailing edge located below the fuselage along a vertical center line of the frame. 2. The aircraft described in item 1. [Item 5] the frame includes a right frame and a left frame extending side by side in the fore-and-aft direction of the airframe, In at least one of the right frame and the left frame, at least a frame portion below the rotation radius of the pull-type rotor has a substantially airfoil-shaped portion inclined in a direction corresponding to the rotation direction of the propeller, and at least a frame portion above the rotation radius of the push-type rotor has a substantially airfoil-shaped portion inclined in a direction that rectifies the air flowing into the propeller. 2. The aircraft described in item 1. [Item 6] the frame includes a right frame and a left frame extending side by side in the fore-and-aft direction of the airframe, In at least one of the right frame and the left frame, at least a frame portion under the rotation radius of the pull-type rotor has a substantially airfoil-shaped portion inclined in a direction corresponding to the rotation direction of the propeller, and in other portions, the substantially airfoil-shaped portion is inclined at an angle different from the inclination, and the leading edge is located on the outer side of the fuselage and the trailing edge is located on the inner side of the fuselage with respect to the vertical center line of the frame. 2. The aircraft described in item 1. [Item 7] the frame includes a front frame and a rear frame; The side area of ​​the rear frame is larger than the side area of ​​the front frame. 7. The aircraft according to any one of items 1 to 6, [Item 8] The frame includes a frame portion located under the rotation radius of the pull-type rotor; The frame portion is located forward of the front frame and has a larger side area than the rear frame. 7. The aircraft according to any one of items 1 to 6,

[0015] <Details of the embodiment of the present invention> Hereinafter, an aircraft according to an embodiment of the present invention will be described with reference to the drawings.

[0016] <Details of the First Embodiment>

[0017] As shown in FIG. 1, an aircraft 100 according to an embodiment of the present invention comprises an aircraft section 20 including elements such as multiple rotor sections each consisting of at least a propeller 110 and a motor 111 for flight, and a frame 21 connecting the rotor sections, and is preferably equipped with energy (e.g., a secondary battery, a fuel cell, a fossil fuel, etc.) for operating these elements. While a single-rotor aircraft or a fixed-wing aircraft may be used as the aircraft, it is preferable to use a VTOL aircraft capable of vertical takeoff and landing, or a rotorcraft with multiple rotors known as a multicopter, particularly for home delivery applications. Using an aircraft capable of vertical takeoff and landing allows for the miniaturization of peripheral equipment, including ports for takeoff and landing.

[0018] The illustrated flying vehicle 100 is depicted in a simplified manner to facilitate explanation of the structure of the present invention, and detailed configurations of, for example, the control unit, etc. are not shown.

[0019] The flying object 100 moves forward in the direction of arrow D in the figure (+Y direction) (details will be described later).

[0020] In the following explanation, terms may be used according to the following definitions: forward / backward direction: +Y direction and -Y direction, up / down direction (or vertical direction): +Z direction and -Z direction, left / right direction (or horizontal direction): +X direction and -X direction, forward direction (forward): +Y direction, backward direction (rearward): -Y direction, upward direction (upward): +Z direction, downward direction (downward): -Z direction

[0021] The propeller 110 rotates upon receiving output from the motor 111. The rotation of the propeller 110 generates a thrust force for causing the flying object 100 to take off from a departure point, move, and land at a destination. The propeller 110 can rotate clockwise, stop, and rotate counterclockwise.

[0022] The propeller 110 of the aircraft of the present invention has one or more blades. Any number of blades (rotors) may be used (e.g., 1, 2, 3, 4, or more blades). The blades may be flat, curved, twisted, tapered, or any combination thereof. The blade shape may be variable (e.g., retractable, foldable, or bent). The blades may be symmetrical (having identical upper and lower surfaces) or asymmetrical (having upper and lower surfaces with different shapes). The blades may be formed into airfoils, wings, or any other geometric shape suitable for generating aerodynamic forces (e.g., lift, thrust) as the blade moves through the air. The blade geometry may be selected to optimize the blade's aerodynamic characteristics, such as increasing lift and thrust and reducing drag.

[0023] The propellers of the aircraft of the present invention may be of fixed pitch, variable pitch, or a combination of fixed pitch and variable pitch, but are not limited to these.

[0024] The motor 111 generates the rotation of the propeller 110; for example, the drive unit may include an electric motor or an engine. The blades may be driven by the motor and rotate around the motor's rotation axis (e.g., the motor's longitudinal axis).

[0025] The blades can all rotate in the same direction, or they can rotate independently. Some blades rotate in one direction and others in the other. The blades can all rotate at the same speed, or they can each rotate at a different speed. The speed can be determined automatically or manually based on the dimensions of the moving object (e.g., size, weight) and the control state (speed, direction of movement, etc.).

[0026] The flying object 100 determines the rotation speed of each motor and the flight angle according to wind speed and direction using a flight controller, radio control, etc. This allows the flying object to move by ascending and descending, accelerating and decelerating, and changing direction.

[0027] The aircraft 100 can fly autonomously according to routes and rules set in advance or during flight, or can fly by being controlled using a radio control.

[0028] The above-described air vehicle 100 has the functional blocks shown in FIG. 6. Note that the functional blocks in FIG. 6 are a minimum reference configuration. The flight controller is a so-called processing unit. The processing unit may have one or more processors, such as a programmable processor (e.g., a central processing unit (CPU)). The processing unit has and can access memory (not shown). The memory stores logic, code, and / or program instructions that the processing unit can execute to perform one or more steps. The memory may include, for example, a separable medium such as an SD card or random access memory (RAM), or an external storage device. Data acquired from a camera or sensors may be directly transmitted to and stored in the memory. For example, still and video data captured by a camera or the like is recorded in an internal or external memory.

[0029] The processing unit includes a control module configured to control the state of the rotorcraft. For example, the control module may have six degrees of freedom (translational x, y, and z, and rotational θ x , θy and θ z The control module controls the propulsion mechanisms (e.g., motors) of the rotorcraft to adjust the spatial position, speed, and / or acceleration of the rotorcraft. The control module can control one or more of the onboard components and the state of the sensors.

[0030] The processing unit can communicate with a transceiver configured to transmit and / or receive data from one or more external devices (e.g., a terminal, a display device, or other remote controller). The transceiver can use any suitable communication means, such as wired or wireless communication. For example, the transceiver can utilize one or more of a local area network (LAN), a wide area network (WAN), infrared, radio, WiFi, a point-to-point (P2P) network, a telecommunications network, cloud communication, etc. The transceiver can transmit and / or receive one or more of data acquired by sensors, processing results generated by the processing unit, predetermined control data, user commands from a terminal or a remote controller, etc.

[0031] The sensors according to this embodiment may include inertial sensors (acceleration sensors, gyro sensors), GPS sensors, proximity sensors (e.g., lidar), or vision / image sensors (e.g., cameras).

[0032] 2-4, the flying unit 20 of the flying vehicle 100 according to the embodiment of the present invention faces the direction of travel when flying and assumes a more forward-leaning posture than when hovering. The forward-leaning rotor generates upward lift and thrust in the direction of travel, which propels the flying vehicle 100 forward.

[0033] The flying object 100 may be equipped with a mounting unit 30 that can fly while holding cargo or people to be transported to a destination, or work sensors or robots (hereinafter collectively referred to as the "loaded object"). The mounting unit 30 may be fixedly connected to the flying unit 20, or may be connected to the flying object 20 via a connecting unit such as a pivot shaft or a gimbal with one or more degrees of freedom so that the object can be kept in a predetermined attitude (for example, horizontal) regardless of the attitude of the flying object 100.

[0034] Known flying section shapes of aircraft include radial frames as shown in Figure 33, ladder frames as shown in Figure 1, and monocoque frames as shown in Figure 32. Radial and ladder frames use carbon or metal pipes with a circular or square cross section. Radial frames are considered suitable for use in photography and hobby applications where the direction of travel is not specified, because the drag of the frame does not change significantly regardless of the direction in which the aircraft travels.

[0035] However, for the frame 21 of the flying section 20 of the aircraft of the present invention, in applications such as transporting people and goods and inspection, it is more desirable to use a ladder-shaped frame or a monocoque frame rather than a radial frame in order to improve flight efficiency specifically in a specific direction (e.g., toward the nose) that is used for a long time, and also to improve efficiency in other directions (e.g., left and right).

[0036] The frame and mounting parts that make up the aircraft 100 are constructed from materials strong enough to withstand flight, takeoff, and landing. For example, resin, FRP, etc. are suitable materials for constructing aircraft because they are rigid and lightweight. Furthermore, when using metal, using a material with a low specific gravity, such as aluminum or magnesium, can improve strength while preventing weight gain.

[0037] Furthermore, the motor mount 23, frame 21, and other components of the flying section 20 may be separate parts that are connected together, or may be molded into a single unit. By integrating the components, it is possible to smooth the joints between the parts, which is expected to reduce drag and improve fuel efficiency.

[0038] The flying vehicle 100 may be equipped with landing legs 40, and the landing legs 40 may further be equipped with shock absorbing devices such as dampers to reduce the impact on the flying vehicle when the landing legs are deployed.

[0039] The frame 21 provided on the flying object 100 is configured to have at least two or more types of cross-sectional shapes in order to reduce the influence of wind on each of the frames when the flying object 100 is cruising.

[0040] For example, in FIG. 3, when the aircraft is subjected to wind from the right side of its direction of travel (hereinafter referred to as "right-wing wind"), the right frame 21b is most affected. In this case, the cross-sectional shape of the right frame 21b may be a substantially airfoil-shaped one. By defining the leading edge of the substantially airfoil-shaped shape on the outer side of the aircraft (outside the fuselage) in the left-right direction (e.g., with respect to the vertical centerline of each frame) and the trailing edge of the substantially airfoil-shaped shape on the inner side of the aircraft (inside the fuselage), drag against wind from the right can be reduced. The "substantially airfoil-shaped" shape here refers to a shape with similar characteristics to a target wing, in that the thickness increases from the leading edge and decreases from a predetermined position toward the trailing edge. However, the substantially airfoil-shaped shape may also be a shape in which the upper surface of the substantially airfoil-shaped shape is less bulged than the lower surface (a so-called inverted airfoil shape), or a shape in which the lower surface is less bulged than the upper surface (a so-called airfoil-shaped shape). This reduces drag when wind hits the leading edge compared to a frame with a circular cross-sectional shape. Furthermore, the main purpose of the approximate airfoil shape in the present invention is to have a shape that efficiently reduces drag, and the shape may differ from that of an airfoil whose main purpose is to generate lift, for example, it may have an inverted airfoil shape.

[0041] Furthermore, when wind comes from the right, the wind is attenuated by the right frame 21b and the main body, and the wind from the right that hits the left frame 21a becomes weaker. Therefore, it is desirable that the left frame 21a be shaped to reduce drag against wind from the left side as viewed from the aircraft (hereinafter collectively referred to as wind from the left), rather than against wind from the right. The cross-sectional shape of each frame may be any shape that is intended to reduce drag, straighten the airflow, etc. A generally wing-shaped shape is more preferable, but shapes that reduce drag and straighten the airflow against wind coming from one or more specific directions, such as an elliptical or trapezoidal shape, are also acceptable.

[0042] The cross-sectional shapes of the right frame 21b and the left frame 21a may be symmetrical or asymmetrical. For example, if the right frame is designed to accommodate wind from the right and the left frame is designed to accommodate wind from the left, the cross-sectional shapes of the left and right frames extending in the front-to-rear direction will be different. Furthermore, if the effects imparted to the left and right frames are symmetrical, the cross-sectional shapes of the frames at the same location in the front-to-rear direction will be symmetrical.

[0043] Furthermore, when the propeller of an aircraft rotates, a twisted airflow called a propeller wake occurs behind the propeller. As shown in Figures 1 to 5, when the rotor of an aircraft is in a pull configuration, the portion of each frame that is within the propeller wake is constantly exposed to wind while the propeller is rotating. The propeller wake contains a lateral component depending on the direction of rotation of the propeller. It is desirable to determine the motor rotation direction so that the propeller wake flows from the outside to the inside of the aircraft relative to the right frame 21b and left frame 21a, respectively.

[0044] Because the shape that reduces drag and rectifies the flow is directional, aligning the direction of the natural wind, which is the target for achieving the effect, and the propeller wake can efficiently reduce drag and rectify the flow. If the rotation directions of all of the motors equipped on the flying vehicle shown in Figure 1 are reversed, the directions of the wind and the propeller wake will be reversed in the left and right directions, and the right frame 21b and left frame 21a may not be able to sufficiently reduce drag and rectify the flow against the propeller wake.

[0045] In other words, in an aircraft whose frame shape is designed to be effective against wind from the outside in the left and right directions of the aircraft, if the direction of the propeller wake generates a lateral wind from the inside to the outside in the left and right directions of the aircraft, it will not be possible to achieve sufficient drag reduction and wind straightening effects.

[0046] Crosswinds due to the surrounding environment can hit the aircraft from different directions, such as directly to the side or diagonally downward, but unless the aircraft is equipped with a special mechanism such as a tilt rotor mechanism, the propeller wake of the pull-type rotor section is a twisted airflow that always hits the frame at a constant angle from diagonally above.The frame shape has an efficient cross-sectional shape in the direction of the propeller wake in areas that are susceptible to the influence of the propeller wake, and a cross-sectional shape that is not dependent on the wind direction of the propeller wake in areas that are not affected by the propeller wake, making it possible to efficiently respond to the wind.

[0047] An example of the cross-sectional shape of the right frame 21b and the left frame 21a in a push-type rotor section is shown in Figure 17, and an example of the cross-sectional shape of the right frame 21b and the left frame 21a in the propeller wake of a pull-type rotor section is shown in Figure 18, but these shapes do not limit the cross-sectional shape or angle of the frames. The cross-sectional shape of each frame should be determined to be a shape that is suitable for the operating environment, cost, etc. of the aircraft 100, and the cross-sectional shape may be changed for each section, resulting in three, four, or more types.

[0048] When the pull configuration and the push configuration are mixed, as in the flying vehicles shown in Figures 9 to 13, it is desirable that the frame near the rotor section of the pull configuration reduces drag against the propeller wake and rectifies the airflow, while the frame near the rotor section of the push configuration rectifies the air flowing toward the propeller.Since the effects to be achieved by each are different, the cross-sectional shapes will also be different.

[0049] When the frontal projection area of ​​the frame 21 of the aircraft in cruising attitude increases compared to when hovering, as in Figure 12, it is expected that flight efficiency will improve by changing the cross-sectional shape of each section of the frame, as shown in Figure 16, for example. At least the CC' cut section of the frame below the rotation radius of the pull rotor blades, which is affected by the propeller wake, is angled to match the rotation direction of the propeller wake, and at least the EE' cut section (and DD' cut section) of the frame above the rotation radius of the push rotor blades, which is not affected by the propeller wake, is angled to match the wind received from the front as the aircraft moves forward, thereby preventing an increase in drag caused by the frame when the aircraft is cruising and improving flight efficiency.

[0050] As shown in Figure 22, when the frame 21 of an aircraft in a cruising attitude is closer to horizontal (the frontal projected area is reduced) compared to when hovering, it is expected that flight efficiency will be improved by changing the cross-sectional shape of each section of the frame, for example, as shown in Figure 24. By providing an angle in the CC' cut section that matches the rotation direction of the propeller wake, an angle in the DD' cut section that matches the wind received from the side of the aircraft due to ambient wind, and an angle in the EE' cut section that matches the wind received from the side of the aircraft due to ambient wind and rectifies the air flowing into the propeller, an increase in drag by the frame when the aircraft is cruising can be prevented, and flight efficiency improved.

[0051] As shown in Figures 19-23, when all the rotors of an aircraft are in a push configuration, the frame 21 is installed in a position that is not affected by the propeller wake. Therefore, the frame in a push configuration does not need to consider the effect on the propeller wake, and only reduces drag caused by winds hitting the aircraft from the left and right. It may also be used to straighten the air before it is drawn into the propeller.

[0052] As described above, the relative wind that strikes the frame of the aircraft during flight changes depending on the presence or absence of a propeller wake due to the rotor configuration, the frame's attitude when moving forward, the propeller size and rotation speed, the aircraft's cruising speed, etc. Therefore, the cross-sectional shape of the frame is determined to be a desirable shape based on these conditions. <Details of the second embodiment> In the details of the second embodiment of the present invention, the components that overlap with those of the first embodiment operate in the same manner, and therefore will not be described again.

[0053] A characteristic feature of this embodiment is that, when the frames have different shapes, the lateral area of ​​the front frame 21(f) and the rear frame 21(r) in a side view is compared, and the rear frame is configured to be wider. More specifically, when the frame 21 is constructed of, for example, round or square pipes, the lateral area (i.e., vertical thickness) of the rear frame portion in a side view is wider than that of the front frame portion. For example, the lateral area may be wider only at a predetermined position at the rear of the frame (more preferably, wide enough to form a surface), or the lateral area may gradually increase from the front to the rear of the frame, or may increase in steps at predetermined intervals. However, this is not limited to these examples. In this case, the horizontal thickness is not limited; the vertical thickness may simply increase while the overall horizontal thickness remains the same, or only a portion of the horizontal thickness may extend vertically. As a result, when the aircraft is exposed to a wind from the side, the rear of the aircraft is more strongly affected by the wind than the front, making it easier for the aircraft's nose to point upwind (the so-called weathervane effect). In relation to the first embodiment, for example, in the cross-sectional shape of FIG. 16, the C-C' cross section is more inclined than the E-E' cross section, so the E-E' cross section has a larger lateral area. This cross-sectional shape provides a weathervane effect. Alternatively, the E-E' cross section may be made longer in the vertical direction than the D-D' cross section, for example. Furthermore, the cross-sectional shape of FIG. 24 also provides a similar weathervane effect. The C-C' cross section has a smaller inclination than the E-E' cross section, so the lateral area is larger. However, the C-C' cross section is located within the rotation radius of a pull-type propeller, so it is strongly influenced by the propeller wake and is less susceptible to crosswinds. On the other hand, the E-E' cross section is located at the push-type propeller, so there is no propeller wake and it is directly influenced by crosswinds. Therefore, the E-E' cross section has a larger lateral area than the D-D' cross section, so the weathervane effect is also provided.In this way, depending on the propeller configuration, it may be possible that the front or rear will not be affected by crosswinds, and in this case, even if the entire front frame section is not narrower than the rear side area, a weather vane effect will be achieved by having a wider rear side area in the front-to-rear relationship except for the frame section located under the rotation radius of the pull-type rotor.

[0054] As a result, particularly in aircraft that can improve flight efficiency when cruising in a nose direction, such as that shown in Patent Document 1, by providing the aircraft with a shape that makes it easy for the nose to face upwind, it is possible to face the aircraft directly against the relative wind and improve flight efficiency.

[0055] Furthermore, as described above, by making the areas of the front frame 21(f) and the rear frame 21(r) different in a side view, and further making the area of ​​the rear frame 21(r) larger in a side view than the area of ​​the front frame 21(f), it is possible to assist in changing the nose direction through automatic control of the aircraft, or to make the nose point naturally upwind even without automatic control of the nose direction.

[0056] Furthermore, if specific parts of an aircraft are made more likely to face upwind, improvements in flight efficiency can be expected not only for aircraft that primarily cruise in a specific direction, but also for aircraft that primarily operate by hovering. For example, if an aircraft has a shape that minimizes drag when the wind hits it from the nose, the nose of the aircraft will naturally face upwind, making it possible to point the nose of the aircraft in the desired direction without controlling the yaw direction.

[0057] The configuration of the aircraft in each embodiment can be implemented by combining multiple configurations. It is desirable to consider an appropriate configuration depending on the cost of manufacturing the aircraft and the environment and characteristics of the location where the aircraft will be operated.

[0058] The above-described embodiment is merely an example for facilitating understanding of the present invention, and is not intended to limit the present invention. The present invention can be modified and improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof. [Explanation of symbols]

[0059] 10 Payload 20 Flying Club 21 frames 23 Motor mount 30 Mounting section 40 landing gear 100 flying objects 110a~110f propeller 111a~111f motor

Claims

1. An aircraft having a flying unit including a frame to which a plurality of rotors, each including at least a propeller and a motor, are connected, The frame has at least two or more types of cross-sectional shapes depending on its position. A flying vehicle characterized by:

2. the frame includes a right frame and a left frame extending side by side in the fore-and-aft direction of the airframe, At least one of the right frame and the left frame has a generally airfoil-shaped portion with a leading edge located on the outer side of the fuselage and a trailing edge located on the inner side of the fuselage with respect to a vertical center line of the frame.

2. The flying vehicle according to claim 1 .

3. The approximately airfoil shape is a target airfoil shape, 3. The flying vehicle according to claim 2.

4. the frame includes a right frame and a left frame extending side by side in the fore-and-aft direction of the airframe, In at least one of the right frame and the left frame, at least a frame portion located under the rotation radius of the pull-type rotor has a substantially airfoil-shaped portion inclined in a direction corresponding to the rotation direction of the propeller, and in other frame portions, the substantially airfoil-shaped portion has a leading edge located above the fuselage and a trailing edge located below the fuselage along a vertical center line of the frame.

2. The flying vehicle according to claim 1 .

5. the frame includes a right frame and a left frame extending side by side in the fore-and-aft direction of the airframe, In at least one of the right frame and the left frame, at least a frame portion below the rotation radius of the pull-type rotor has a substantially airfoil-shaped portion inclined in a direction corresponding to the rotation direction of the propeller, and at least a frame portion above the rotation radius of the push-type rotor has a substantially airfoil-shaped portion inclined in a direction that rectifies the air flowing into the propeller.

2. The flying vehicle according to claim 1 .

6. the frame includes a right frame and a left frame extending side by side in the fore-and-aft direction of the airframe, In at least one of the right frame and the left frame, at least a frame portion under the rotation radius of the pull-type rotor has a substantially airfoil-shaped portion inclined in a direction corresponding to the rotation direction of the propeller, and in other portions, the substantially airfoil-shaped portion is inclined at an angle different from the inclination, and the leading edge is located on the outer side of the fuselage and the trailing edge is located on the inner side of the fuselage with respect to the vertical center line of the frame.

2. The flying vehicle according to claim 1 .

7. the frame includes a front frame and a rear frame; The side area of ​​the rear frame is larger than the side area of ​​the front frame.

7. The flying vehicle according to claim 1, wherein the flying vehicle is a vehicle having a wing.

8. The frame includes a frame portion located under the rotation radius of the pull-type rotor; The frame portion is located forward of the front frame and has a larger side area than the rear frame.

7. The flying vehicle according to claim 1, wherein the flying vehicle is a vehicle having a wing.

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