aircraft

Abstract

The present invention relates to an aircraft, and the subject is to efficiently cool the electrical components of the rotor using the airflow generated by the rotor. The aircraft (100) of the present invention comprises: a fuselage (12); a front wing (14) and a rear wing (16) extending laterally from the fuselage and generating lift during cruising; a boom (18) supported by the front wing and the rear wing separately from the fuselage and extending in the front-to-back direction; at least one VTOL rotor (20) supported on the boom and having one or more blades (23) generating thrust in the vertical direction during takeoff and landing; and a cooling system (60) having two radiators (61L, 61H) housed in the boom between an inlet (70a) and an outlet (70b) of the boom, wherein the radiator located on the inlet side and the radiator located on the outlet side of the two radiators are used to cool the electrical components of the at least one VTOL rotor with a low management temperature and the electrical components with a high management temperature, such as the motor (21) and the inverter (22).

Description

Technical Field

[0001] The present invention relates to aircraft. Background Art

[0002] In the prior art, a vertical take-off and landing aircraft (referred to as a VTOL aircraft or simply an aircraft) is known, which uses take-off and landing (VTOL) rotors arranged on the left and right sides of the fuselage to rise and fall in the vertical direction for take-off and landing, and uses cruise rotors arranged at the rear of the fuselage to fly in the horizontal direction. In this aircraft, the airflow (downwash) generated by the VTOL rotor is used to cool electrical components such as the controller of the VTOL rotor. For example, Patent Document 1 discloses a cooling system that guides airflow through an inlet provided on the upper surface of the wing to a heat exchanger within the wing body and performs heat exchange, and uses this heat exchanger to cool the electrical components of the VTOL rotor. Here, it is required to efficiently cool the electrical components of the VTOL rotor.

[0003] Patent Document 1: German Patent Invention No. 102016125656 Summary of the Invention

[0004] In one embodiment of the present invention, an aircraft is provided, comprising: a fuselage; a wing extending laterally from the fuselage to generate lift during cruising; a boom supported by the wing separately from the fuselage and extending in a front-to-rear direction; at least one rotor supported on the boom and having one or more blades for generating thrust in a vertical direction during takeoff and landing; and a cooling system comprising two radiators housed in the boom between an inlet and an outlet of the boom, wherein a first radiator located on the inlet side and a second radiator located on the outlet side of the two radiators are used to cool a low-management-temperature element and a high-management-temperature element of the at least one rotor, respectively.

[0005] In addition, the above invention summary does not list all the features of the present invention. Moreover, sub-combinations of these feature groups can also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 The structure of the aircraft according to this embodiment is shown in a plan view.

[0007] Figure 2A Shows the internal structure of the boom.

[0008] Figure 2B This is a diagram showing the structure of the radiator from the front view.

[0009] Figure 2C This is a diagram showing the structure of the radiator from a side view.

[0010] Figure 2DAn example of a cooling circuit constituted by a cooling system is shown.

[0011] Figure 3 Shown with Figure 2A Cross-sectional structure of the airflow guide structure relative to the reference line CC in FIG.

[0012] Figure 4A The structure of the upper side of the airflow guide structure and the arrangement of the inlets are shown.

[0013] Figure 4B The structure of the lower side of the airflow guide structure and the arrangement of the outlets are shown.

[0014] Figure 5A Another example of a cooling circuit constituted by a cooling system is shown.

[0015] Figure 5B The structure of the control system of the cooling system is shown.

[0016] Figure 6A Show Figure 5A An example of the operation of the cooling circuit (operation during rising).

[0017] Figure 6B Show Figure 5A An example of the operation of the cooling circuit (operation when an abnormality occurs during ascent). DETAILED DESCRIPTION

[0018] The present invention is described below by way of embodiments of the invention, but the following embodiments do not limit the invention as to the scope of protection of the claims. In addition, not all combinations of features described in the embodiments are essential to the solution of the invention.

[0019] Figure 1 , the structure of an aircraft 100 according to this embodiment is shown in a top view. Aircraft 100 is a vertical take-off and landing (VTOL) aircraft equipped with rotors having electric motors as drive sources. It uses the take-off and landing (VTOL) rotors to generate thrust for vertical take-off and landing, and uses the cruise rotors (also called cruise rotors) to generate thrust for horizontal flight. Aircraft 100 is also a hybrid aircraft, capable of operating the electric motors using power supplied by batteries and electric generators, respectively, and charging the batteries using the electric generators. Aircraft 100 according to this embodiment particularly includes a cooling system that utilizes the airflow (i.e., downwash) generated by the VTOL rotors to efficiently cool the motors and control equipment that constitute the VTOL rotors. Aircraft 100 includes a fuselage 12, a front wing 14, a rear wing 16, two booms 18, eight VTOL rotors 20, two cruise rotors 29, a cooling system 60, and an airflow guide structure 70.

[0020] The fuselage 12 is a structure that provides space for crew members, passengers, and cargo, and houses devices such as batteries and electric generators (neither of which are shown). The fuselage 12 is bilaterally symmetrical about a central axis L, extending in a front-to-back direction parallel to the central axis L and tapering in a horizontally perpendicular direction to the central axis L. Here, the direction parallel to the central axis L is referred to as the front-to-back direction, the left side of the drawing and the right side of the drawing are referred to as the front (F) and the back (B), respectively. The direction perpendicular to the central axis L in the horizontal plane is referred to as the width direction (or left-to-right direction), and the top and bottom of the drawing are referred to as the right (R) and the left (L), respectively. Furthermore, the vertical direction is perpendicular to these front-to-back and width directions, and the vertical directions upward and downward are also referred to as upward (U) and downward (L), respectively. When viewed from above, the fuselage 12 has a smoothly curved front end and a rear end that is slightly tapered relative to the main body and parallel to the width direction.

[0021] The canard 14 is a wing body extending laterally from the fuselage 12. During cruising, it generates lift by moving forward, functioning as a canard for the aircraft 100. The canard 14 has two wing bodies extending from a center portion in a V-shape toward the left and right front, respectively. The canard 14 is fixed to the upper front portion of the main body of the fuselage 12 at the center portion, with the opening of the V facing forward. The canard 14 includes elevators 14a located at the trailing edge of each of the two wing bodies.

[0022] The rear wing 16 extends laterally from the fuselage 12 and generates lift by moving forward during cruising, functioning as a swept wing to reduce air resistance. The rear wing 16 has two wing bodies extending from a center portion to the left and right rearwards, respectively, in a V-shape. The rear wing 16 is secured to the upper portion of the rear end of the fuselage 12 at the center portion via a hanger 32, with the opening of the V facing rearward. The rear wing 16 includes ailerons 16a arranged on the double wires of each of the two wing bodies and a vertical tail 16b arranged at the wing tips.

[0023] Here, the rear wing 16 has a larger wing area than the front wing 14, and its wing width is greater than the front wing. Therefore, during forward movement, the lift generated by the rear wing 16 is greater than the lift generated by the front wing 14, and the rear wing 16 functions as the main wing of the aircraft 100. Furthermore, the wing area, length, and other factors of the front wing 14 and rear wing 16 can be determined based on the balance of lift generated by each, the position of the center of gravity, and the aircraft's posture during cruising.

[0024] The two booms 18 are structures supported by the front wing 14 and the rear wing 16, separated from the fuselage 12 to the left and right. They support or house various components of the VTOL rotors 20 and cooling system 60, described later. The two booms 18 have a cylindrical shape extending in the fore-aft direction when viewed from above, and a cross-sectional shape resembling an airfoil, with a smoothly curved upper side and a tapered lower side, when viewed from the front. They are arranged in a pair, symmetrically with respect to the fuselage 12 (i.e., the central axis L). Alternatively, the two booms 18 may extend in the fore-aft direction and curve in an arcuate manner in the width direction. The front ends of the two booms 18 are located forward of the front wing 14 and supported by the front main body (between the two front VTOL rotors 20a and 20b). The rear ends are located rearward of the rear wing 16 and supported by the rear main body (between the two rear VTOL rotors 20c and 20d).

[0025] Figure 2A The internal structure of the boom 18 is shown. The boom 18 includes a skin 18a, ribs 18b, and beams 18c. The skin 18a is a component constituting the surface of the boom 18, has an airfoil-shaped cross-sectional shape, and is formed into a cylindrical shape extending in the front-to-back direction. The skin 18a bulges upward at the portion where the VTOL rotor 20 is arranged and expands in the left-to-right direction to form a space 18d, and bulges slightly upward at the portion where the cooling system 60 is arranged and expands in the left-to-right direction to form a space 18e. The ribs 18b are plate-like components of the airfoil shape, which are arranged at multiple locations in the front-to-back direction and hold the skin 18a from the inside. In addition, the spaces 18d and 18e in the boom 18 are divided by the ribs 18b. The beam 18c is a rod-shaped component extending in the front-to-back direction, which constitutes a skeleton supporting the ribs 18b and other components.

[0026] Eight VTOL rotors 20 (20a-20d) are supported by two booms 18 and generate vertical thrust during takeoff and landing. Four of the eight VTOL rotors 20 are supported by the left boom 18 at approximately equal intervals, while the remaining four are supported by the right boom 18 at approximately equal intervals. The VTOL rotor 20a is positioned forward, while the two VTOL rotors 20b and 20c are positioned front-to-back between the front wing 14 and the rear wing 16. The VTOL rotor 20d is positioned rearmost. The left VTOL rotors 20a-20d and the four right VTOL rotors 20a-20d are paired with two VTOL rotors 20a-20d positioned in the same forward-to-back direction and controlled to rotate in opposite directions. Unless otherwise specified, each of the eight VTOL rotors 20 a to 20 d is simply referred to as a VTOL rotor 20 .

[0027] The VTOL rotor 20 includes one or more blades 23, a motor 21, and an inverter 22. The motor 21 and the inverter 22 are also referred to as electrical components.

[0028] like Figure 2A As shown, one or more blades 23 are wing-shaped components supported on the boom 18 and generating thrust in the vertical direction by rotating. In this embodiment, the number of blades 23 is two, but it can also be any number of one or three or more. One or more blades 23 are supported at a position higher than the front wing 14 and the rear wing 16. In addition, Figure 1 In FIG. 1 , the rotation plane of one or more blades 23 of each VTOL rotor 20 is indicated by a two-dot chain line.

[0029] The motor (an example of a rotating device) 21 is an electric motor having a rotating shaft 21 a directed in the vertical direction and rotating a blade 23 fixed to the tip via the rotating shaft 21 a . The motor 21 is supported by the beam 18 c via a supporting member and housed in the space 18 d of the boom 18 .

[0030] The inverter 22 (an example of a control device) receives DC power from a battery, converts it into AC power, and supplies it to the motor 21. The inverter 22 is supported by the beam 18c below the motor 21. The inverter 22 can control the rotation speed of the motor 21.

[0031] The two cruise rotors 29 are supported at the rear end of the fuselage 12 and generate thrust during cruise. These rotors are arranged side by side with respect to the central axis L within a cylindrical duct 54 fixed to the rear end of the fuselage 12. They comprise: one or more blades supported within the duct 54, which rotate to generate forward thrust; a motor with a forward-facing rotational shaft that rotates the one or more blades fixed to the tip; and an inverter that receives DC power from a battery, converts it to AC power, and supplies it to the motor (both not shown). The inverter controls the motor's rotational speed.

[0032] The cooling system 60 uses a radiator 61 located within the boom 18 to liquid-cool the motor 21 and inverter 22 that make up the VTOL rotor 20. In this embodiment, one cooling system 60 is provided for each VTOL rotor 20, for a total of eight cooling systems 60. However, this is not limiting; one cooling system 60 may be provided for multiple (e.g., two) VTOL rotors 20. The cooling system 60 includes a radiator 61, two pumps 62L and 62H, a coolant tank 63, and pipes 64L, 64H, 65L, and 65H. Water can also be used as the coolant.

[0033] Figure 2B and Figure 2C, the structure of the radiator 61 is shown in a front view and a side view, respectively. The radiator 61 is a heat exchanger that cools the coolant used to cool the motor 21 and inverter 22. It includes two radiators 61L and 61H and two fans 61e. These are supported between two ribs 18b using a support member 61f and housed within the suspension rod 18 via an airflow guide structure 70, described later. The placement of the radiator 61 within the suspension rod 18 will be described later.

[0034] The two radiators 61L and 61H respectively have: multiple tubes 61a1 and 61a2 for the coolant to flow up and down, multiple fins 61b1 and 61b2 respectively fixed to the multiple tubes 61a1 and 61a2 to increase the surface area contacted by the airflow, upper tanks 61c1 and 61c2 for transporting the coolant to the multiple tubes 61a1 and 61a2, and lower tanks 61d1 and 61d2 for receiving the coolant from the multiple tubes 61a1 and 61a2.

[0035] The radiator 61L is constructed by arranging multiple tubes 61a1 horizontally and assembling them together with multiple fins 61b1 to form a rectangular shape in front view. An upper tank 61c1 is secured to the upper side of the radiator, while a lower tank 61d1 is secured to the lower side. As described later, the radiator 61L is located within the boom 18, near the inlet 70a. It is connected to components with low-temperature management among the electrical components of the VTOL rotor 20, such as the motor 21. Coolant heated by the operation of a pump 62L (described later) circulates through the motor 21 and is then fed into the upper tank 61c1 via a pipe 64L. The coolant flows downward through the multiple tubes 61a1, where it is cooled and delivered to the lower tank 61d1. The coolant is then delivered to the motor 21 via a pipe 65L.

[0036] Similarly, the radiator 61H is constructed by arranging multiple tubes 61a2 in a horizontal direction and assembling them together with multiple fins 61b2 to form a rectangular shape in front view. An upper tank 61c2 is secured to the upper side of the radiator, while a lower tank 61d2 is secured to the lower side. As described later, the radiator 61H is located within the boom 18, near the outlet 70b, and is connected to components with high-temperature management among the electrical components of the VTOL rotor 20, such as the inverter 22. Coolant, heated by operation of a pump 62H (described later), circulates through the inverter 22 and is then fed into the upper tank 61c2 via a pipe 64H. The coolant flows downward through the multiple tubes 61a2, where it is cooled and delivered to the lower tank 61d2. The coolant is then delivered to the inverter 22 via a pipe 65H.

[0037] It should be noted that the management temperature refers to a temperature range or a critical temperature within which the electrical components of the VTOL rotor 20 can operate continuously, and may be, for example, an upper limit temperature of the electrical components during normal operation.

[0038] The two fans 61e are common fans that deliver airflow to the multiple fins 61b1 and 61b2 of the two radiators 61L and 61H. The two fans 61e operate so that the airflow sucked from the inlet 70a is directed from one side of the radiator 61 ( Figure 2C The airflow is fed into the heat sink 61L and the heat sink 61H and contacts the fins 61b1 and 61b2 of the heat sink 61L and 61H in sequence, thereby exchanging heat with the heat sink 61L and 61H. The heated airflow is fed into the heat sink 61L and the heat sink 61H from the other side ( Figure 2C The left side of the image is detached and ejected.

[0039] The two pumps 62L and 62H are connected to the radiators 61L and 61H via pipes 65L and 65H, respectively, and receive cooled coolant from the radiators 61L and 61H and deliver it to the motor 21 and inverter 22. Simultaneously, the coolant heated by the motor 21 and inverter 22 is delivered to the radiators 61L and 61H via pipes 64L and 64H, respectively.

[0040] The cooling liquid tank 63 is a container for storing cooling liquid. For example, when the cooling liquid is insufficient, the cooling liquid is transported from the cooling liquid tank 63 to the cooling circuit to replenish the cooling liquid.

[0041] The pipes 64L, 64H, 65L, and 65H are components for conveying the coolant, and connect the radiators 61L and 61H and the pumps 62L and 62H to the motor 21 and the inverter 22 to form a cooling circuit in which the coolant circulates.

[0042] Figure 2D An example of a cooling circuit formed by the cooling system 60 is shown. In this embodiment, two radiators 61L and 61H form a parallel cooling circuit that cools the motor 21 and inverter 22 of a single VTOL rotor 20, respectively. The upper tanks 61c1 and 61c2 of the radiators 61L and 61H are connected to the motor 21 and inverter 22, respectively, via two pipes 64L and 64H. Furthermore, the lower tanks 61d1 and 61d2 of the radiators 61L and 61H are connected to the motor 21 and inverter 22, respectively, via two pipes 65L and 65H, via pumps 62L and 62H. A coolant tank 63 is connected to the two pipes 65L and 65H. The exhaust surface of the radiator 61L and the intake surface of the radiator 61H are arranged to face and overlap, with the radiators 61L and 61H positioned on the inlet 70a and outlet 70b sides, respectively.

[0043] When pump 62L is operated, the coolant heated by motor 21 is sent to radiator 61L via pipe 64L, and the coolant cooled by radiator 61L is sent to motor 21 via pipe 65L. On the other hand, when pump 62H is operated, the coolant heated by inverter 22 is sent to radiator 61H via pipe 64H, and the coolant cooled by radiator 61H is sent to inverter 22 via pipe 65H.

[0044] Here, when the two fans 61e are operating, the airflow drawn in from inlet 70a first contacts the heat sink 61L located on the inlet 70a side, exchanging heat and being heated. It then contacts the heat sink 61H located on the outlet 70b side, exchanging heat and being further heated, before being discharged from outlet 70b. At this point, the heat sink 61L, which is cooled by contact with the airflow first and has a relatively low operating temperature, cools the low-temperature electrical components, while the heat sink 61H, which is cooled by contact with the airflow later and has a relatively high operating temperature, cools the high-temperature electrical components. This allows for efficient cooling of the electrical components of the VTOL rotor 20, namely, the motor 21 and inverter 22.

[0045] Furthermore, a cooling system having the same configuration as the cooling system 60 may be provided to cool the electrical components of the cruise rotor 29 .

[0046] Figure 3 express Figure 2A The cross-sectional structure of the airflow guide structure 70 at the reference line CC in FIG. In addition, the central axis of the airflow guide structure 70 in the width direction is taken as the central axis L. 70 . Center axis L 70 The airflow guide structure 70 is parallel to the rotation axis 21a of the VTOL rotor 20 and overlaps the rotation axis 21a in the front-to-back direction at the same position in the width direction. The airflow guide structure 70 is provided on a portion of the boom 18 and guides the airflow generated by the rotation of one or more blades 23 to the radiator 61 within the boom 18. The structure includes an upper structure 71 and a lower structure 72.

[0047] The upper structure 71 is a component having a main body that is inserted into the boom 18 and has a roughly inverted L-shaped cross-section forming an upper side and a right side. The upper structure 71 can be formed into a solid shape, with the top of the upper side tilted obliquely upward to the left, and a recess 71b extending obliquely downward and in the front-to-back direction formed on the lower surface of the upper side. The inner surface of the right side (i.e., the left surface) is formed into a streamlined shape that bulges to the right and slightly retracts to the left on a surface perpendicular to the front-to-back direction and extends downward from the recess 71b. The upper side of the upper structure 71 functions as a beam 71a that is installed on the upper side of the inlet 70a formed between the upper structure 71 and the lower structure 72. In this way, it is possible to resist the bending stress applied to the boom 18 including the airflow guide structure 70.

[0048] The lower structure 72 is a component having a main body that is inserted into the boom 18 and has a roughly L-shaped cross-section that forms a lower side and a left side. The lower structure 72 can be formed into a solid body, with a recess 72b formed on the upper surface of the lower side that faces obliquely upward and extends in the front-to-back direction. The right top of the lower side is inclined downward, and the upper end of the left side is inclined obliquely upward to the left. The inner surface of the left side (i.e., the right surface) is formed into a streamlined shape that extends from the upper end to the bottom in a manner that bulges slightly to the right and then retracts slightly to the left on a plane perpendicular to the front-to-back direction. The lower side of the lower structure 72 functions as a beam 72a that is installed on the lower side of the outlet 70b formed between the upper structure 71 and the lower structure 72. As a result, it is possible to resist the bending stress applied to the boom 18 including the airflow guide structure 70.

[0049] The airflow guide structure 70 is assembled using the upper structure 71 and the lower structure 72 of the above structure, and an inlet 70 a for sucking airflow is formed on the upper side and an outlet 70 b for ejecting airflow is formed on the lower side in the boom 18 . First, the two radiators 61L and 61H and the fan 61e are stacked. Next, the upper structure 71 is fixed to the beam 18c. The upper tanks 61c1 and 61c2 of the two radiators 61L and 61H are fitted into the recessed portions 71b of the upper structure 71, and the brackets provided on the upper tanks 61c1 and 61c2 are fixed to the beam 18c. Next, the lower structure 72 is fixed to the spar 18c. The lower tanks 61d1 and 61d2 of the radiators 61L and 61H are fitted into the recessed portions 72b of the lower structure 72, and the brackets provided on the lower tanks 61d1 and 61d2 are fixed to the beam 18c. This completes the integral assembly of the airflow guide structure 70 to the main body of the boom 18. At this point, the two radiators 61L and 61H and the fan 61e are supported between the two ribs 18b within the boom 18 using the support member 61f.

[0050] Thus, the inlet 70a is formed on one surface (suction surface) of the radiators 61L and 61H between the upper side of the upper structure 71 and the left side of the lower structure 72, and the outlet 70b is formed on the other surface (exhaust surface) of the radiators 61L and 61H between the right side of the upper structure 71 and the lower side of the lower structure 72. Furthermore, within the boom 18, the radiators 61L and 61H are disposed on the inlet 70a side and the outlet 70b side, respectively, between the inlet 70a and the outlet 70b, and are aligned with the rotation axis 21a (i.e., the center axis L) of the VTOL rotor 20. 70 ) and overlap in a direction parallel to the central axis L 70 The radiator 61H is tilted so that the suction surface faces the inlet 70a and the exhaust surface faces the outlet 70b. Furthermore, two fans 61e are positioned on the exhaust side of the radiator 61H. Alternatively, two fans 61e can be positioned on the intake side of the radiator 61L. This ensures that the airflow drawn in from the inlet 70a sequentially contacts the two radiators 61L and 61H.

[0051] Figure 4A The figure shows the structure of the airflow guide structure 70 provided on the upper side of the boom 18. As an example, the airflow guide structure 70 includes a radiator 61 for cooling the right VTOL rotor 20b, and is provided on the boom body between the rotation axes 21a of the two VTOL rotors 20a and 20b (i.e., in front of the VTOL rotor 20b). The airflow guide structure 70 provides an inlet 70a on the surface of the boom 18 between the rotation axes 21a of the two VTOL rotors 20a and 20b, and is provided on the surface of the boom 18 below the rotation plane of one of the two VTOL rotors 20a and 20b, in this example, specifically one or more blades 23 of the VTOL rotor 20b, and relative to the rotation axis 21a (center axis L) of the VTOL rotor 20b in a front view. 70 ) toward one side of the rotation direction (rightward in this example) of one or more blades 23, that is, toward the opposite side of the rotation direction (leftward in this example).

[0052] Here, the blades 23 of the VTOL rotor 20 have a pitch angle relative to the rotation plane to generate thrust (see Figure 2A ). Therefore, for example, when the blade 23 is Figure 4A When the blade 23 rotates clockwise as shown, the blade 23 rotates in a direction inclined downward relative to the direction of rotation, that is, in a direction obliquely downward to the right ( Figure 3 Thus, in the airflow guide structure 70, the inlet 70a is oriented relative to the rotation axis 21a (center axis L) of the VTOL rotor 20b in the front view. 70) is arranged on the left side, so that when the two VTOL rotors 20a and 20b are started, the airflow generated by the rotation of at least one of the rotors, in this example, especially one or more blades 23 of the VTOL rotor 20b, can be efficiently guided to the radiator 61 in the boom 18 through the inlet 70a.

[0053] In addition, if Figure 3 As shown, the top end of the upper side of the upper structure 71 of the airflow guide structure 70 is inclined obliquely upward to the left, and the upper end of the left side of the lower structure 72 is inclined obliquely upward to the left. Therefore, in the airflow guide structure 70, the top end of the upper side of the upper structure 71 and the upper end of the left side of the lower structure 72 are opposite to each other, thereby, the inlet 70a is inclined relative to the central axis L. 70 The rotation direction of the blade 23 of the VTOL rotor 20b ( Figure 3 Thus, the airflow generated by the rotation of one or more blades 23 of the VTOL rotor 20b can be efficiently guided to the radiator 61 in the boom 18 via the inlet 70a.

[0054] Furthermore, the airflow guide structure 70 for the VTOL rotor 20b may be provided, in addition to or in addition to the boom body provided between the rotational axes 21a of the two VTOL rotors 20a and 20b, with a boom body provided between the rotational axes 21a of the two VTOL rotors 20b and 20c (i.e., behind the VTOL rotor 20b). In this case, the airflow guide structure 70 is provided on the surface of the boom 18 below the rotational plane of one of the two VTOL rotors 20b and 20c, in this example, specifically one or more blades 23 of the VTOL rotor 20b, relative to the rotational axis 21a (center axis L) of the VTOL rotor 20b in a front view. 70 ) toward one side of the rotation direction (left in this example) of one or more blades 23, that is, the opposite side of the rotation direction (right in this example). 70 The VTOL rotor 20b is tilted obliquely upward and to the right in the direction of rotation of the blades 23 (left in this example). This allows the airflow generated by the rotation of one or more blades 23 of the VTOL rotor 20b to be efficiently guided to the radiator 61 in the boom 18 via the inlet 70a.

[0055] Figure 4B The structure of the lower side of the aforementioned airflow guide structure 70 is shown. With the airflow guide structure 70, the outlet 70b is provided on the lower side of the boom 18 at a position opposite the inlet 70a. As a result, airflow introduced through the upper inlet 70a passes through the interior of the boom 18 and is discharged downward from the lower outlet 70b, thereby enabling airflow to efficiently pass through the interior of the boom 18.

[0056] In the lower part of the boom 18, in the front view, the outlet 70b is in this example relative to the rotation axis 21a (central axis L of the VTOL rotor 20b). 70 ) is provided on the side that follows the rotation direction of one or more blades 23 (right direction in this example), that is, on the side corresponding to the rotation direction (right direction in this example). In other words, the outlet is relative to the rotation axis 21a (center axis L) of the VTOL rotor 20b in the lower part of the boom 18. 70 ) is located on the opposite side of the inlet 70a. As a result, the airflow introduced through the inlet 70a has a longer flow path in the boom 18, contacts the radiator 61 over a long distance and is guided out from the outlet 70b, thereby efficiently cooling the radiator 61.

[0057] In addition, if Figure 3 As shown, the right top end of the lower side of the lower structure 72 of the airflow guide structure 70 is formed to face downward, and the left inner surface of the right side of the upper structure 71 is formed to be streamlined downward. Therefore, in the airflow guide structure 70, the right top end of the lower side of the lower structure 72 is opposite the lower end of the right side of the upper structure 71. As a result, the outlet 70b faces downward relative to the inlet 70a, which is tilted upward and to the left. As a result, the airflow introduced into the interior of the boom 18 from the inlet 70a to the right and downward is discharged further downward through the outlet 70b, thereby increasing the vertical thrust applied to the boom 18 (i.e., the fuselage of the aircraft 100). In addition, by constructing the airflow guide structure 70 in this manner, the output of the fan 61e can also be used as the vertical thrust applied to the boom 18 (i.e., the fuselage).

[0058] The airflow guide structure 70 (i.e., the radiator 61) can be installed at any position in the front-to-back direction within the boom 18. For example, between the rotational shafts 21a of the VTOL rotors 20a and 20b, an airflow guide structure 70 including the radiator 61 for cooling the VTOL rotor 20a can be installed on the rear side of the VTOL rotor 20a, and an airflow guide structure 70 including the radiator 61 for cooling the VTOL rotor 20b can be installed on the front side of the VTOL rotor 20b. Furthermore, between the rotational shafts 21a of the VTOL rotors 20b and 20c, an airflow guide structure 70 including the radiator 61 for cooling the VTOL rotor 20b can be installed on the rear side of the VTOL rotor 20b, and an airflow guide structure 70 including the radiator 61 for cooling the VTOL rotor 20c can be installed on the front side of the VTOL rotor 20c. Furthermore, between the rotational shafts 21a of the VTOL rotors 20c and 20d, an airflow guide structure 70 including a radiator 61 for cooling the VTOL rotor 20c can be provided on the rear side of the VTOL rotor 20c, and an airflow guide structure 70 including a radiator 61 for cooling the VTOL rotor 20d can be provided on the front side of the VTOL rotor 20d. Alternatively, the radiator 61 for cooling the VTOL rotor 20b can be provided on only one of the front and rear sides. Alternatively, the radiator 61 for cooling the VTOL rotor 20c can be provided on only one of the front and rear sides of the VTOL rotor 20c.

[0059] Alternatively, one airflow guide structure 70 including a radiator 61 for cooling the VTOL rotors 20a and 20b may be provided between the rotational shafts 21a of the VTOL rotors 20b and 20c, one airflow guide structure 70 including a radiator 61 for cooling the VTOL rotors 20b and 20c, and one airflow guide structure 70 including a radiator 61 for cooling the VTOL rotors 20c and 20d. When configuring a parallel cooling circuit for simultaneously cooling two adjacent VTOL rotors 20, these locations are suitable as locations for installing the airflow guide structures 70 including two radiators.

[0060] Furthermore, the airflow guide structure 70 can be located at least partially at the location where the boom 18 connects to the front wing 14, thereby enabling the airflow guide structure 70 to be more stably secured to the boom 18 using, for example, the frame of the front wing 14. Alternatively, the airflow guide structure 70 can be located on the main body of the boom 18 supported between the front wing 14 and the rear wing 16, thereby enabling the airflow guide structure 70 to be more stably secured to the boom 18. Alternatively, the airflow guide structure 70 can be located at least partially at the location where the boom 18 connects to the rear wing 16, thereby enabling the airflow guide structure 70 to be more stably secured to the boom 18 using, for example, the frame of the rear wing 16.

[0061] Furthermore, the airflow guide structure 70 (i.e., the heat sink 61) may be provided between the rotational axes 21a of two adjacent VTOL rotors 20, which rotate in opposite directions and whose blades 23 rotate in the same direction between their respective rotational axes 21a. Thus, when at least one of the two adjacent VTOL rotors 20 is started, the airflow generated by the rotation of one or more blades 23 of that rotor, or preferably both rotors, can be efficiently guided through the inlet 70a of the airflow guide structure 70 to the heat sink 61 within the boom 18.

[0062] Figure 5A Another example of a cooling circuit formed by the cooling system 60 is shown. The cooling system 60 of this example uses two radiators 61L and 61H to cool a plurality of VTOL rotors 20. More specifically, a parallel cooling circuit is formed, in which the radiator 61L is used to cool in parallel the electrical components of the two VTOL rotors 20 with low management temperatures, such as the motor 21, and the radiator 61H is used to cool in parallel the electrical components of the two VTOL rotors 20 with high management temperatures, such as the inverter 22. As an example, a cooling circuit is described in which the motors 21 and inverters 22 of the two VTOL rotors 20a and 20b are cooled using the radiators 61 (two radiators 61L and 61H) arranged in the boom 18 between the rotating shafts 21a of the two VTOL rotors 20a and 20b. The coolant tank 63 is not shown in the figure.

[0063] The cooling system 60 of this example includes: a radiator 61L, motors 21 for two VTOL rotors 20a and 20b, a pump 62L for supplying coolant to the two motors 21, pipes 64L and 65L connecting them (the flow path formed by the pipe connected to the radiator 61L is referred to as a first flow path 66L), a radiator 61H, inverters 22 for two VTOL rotors 20a and 20b, a pump 62H for supplying coolant to the two inverters 22, pipes 64H and 65H connecting them (the flow path formed by the pipe connected to the radiator 61H is referred to as a second flow path 66H), two third flow paths 66P connecting the two motors 21 in the first flow path 66L and the two inverters 22 in the second flow path 66H in parallel, and four valves 67 for opening and closing the two third flow paths 66P with respect to the first flow path 66L and the second flow path 66H.

[0064] The upper tanks 61c1 and 61c2 of the radiators 61L and 61H are connected to the motors 21 and inverters 22 of the VTOL rotors 20a and 20b, respectively, via two pipes 64L and 64H. Furthermore, the lower tanks 61d1 and 61d2 of the radiators 61L and 61H are connected to the motors 21 and inverters 22 of the VTOL rotors 20a and 20b, respectively, via two pipes 65L and 65H, respectively, via pumps 62L and 62H. Thus, the two motors 21 of the VTOL rotors 20a and 20b are connected in parallel to the radiator 61L via the pump 62L, and the two inverters 22 of the VTOL rotors 20a and 20b are connected in parallel to the radiator 61H via the pump 62H. Here, the radiators 61L and 61H are arranged on the inlet 70a side and the outlet 70b side, respectively, so that the exhaust surface of the radiator 61L and the intake surface of the radiator 61H face and overlap.

[0065] Furthermore, a third flow path 66P is connected between the pipe 64L of the first flow path 66L and the pipe 64H of the second flow path 66H via a valve 67. Also, a third flow path 66P is connected between the pipe 65L of the first flow path 66L and the pipe 65H of the second flow path 66H via a valve 67. Thus, by opening and closing the valve 67, the inverter 22 can be connected in parallel with the motor 21 in the first flow path 66L, or the motor 21 can be connected in parallel with the inverter 22 in the second flow path 66H, via the third flow path 66P. In the event of a failure in either the radiator 61L and pump 62L, or the radiator 61H and pump 62H, the motor 21 and inverter 22 can be cooled using the other radiator and pump.

[0066] Figure 5B The configuration of the control system of the cooling system 60 of this example is shown. The control system includes sensors provided to the two radiators 61L and 61H, sensors provided to the two pumps 62L and 62H, four valves 67 , and a control unit 69 .

[0067] These four sensors can, for example, detect the stopping of radiators 61L and 61H and pumps 62L and 62H. Alternatively, they can detect abnormalities by monitoring the coolant's pressure, temperature, flow rate, and other conditions. The detection results are transmitted to the control unit 69.

[0068] The four valves 67 are switching valves, for example, three-way switching valves, that switchably connect the pipes 64L, 64H, 65L, and 65H, the pipes of the third flow path 66P, and the motor 21 or the inverter 22. The valves 67 are controlled and operated by the control unit 69.

[0069] The control unit 69 is a computer device that performs control functions for the cooling system 60 by executing a control program. The control unit 69 receives detection signals from sensors provided on the two radiators 61L and 61H and the two pumps 62L and 62H. If no abnormality is detected, the control unit 69 opens and closes the valve 67, closing the two third flow paths 66P and separating the first flow path 66L from the second flow path 66H. If an abnormality is detected in any of the two radiators 61L and 61H and the two pumps 62L and 62H, the control unit 69 opens and closes the four valves 67, opening the two third flow paths 66P and closing the second flow path 66H to connect the inverter 22 in parallel with the motor 21 in the first flow path 66L, or closing the first flow path 66L to connect the motor 21 in parallel with the inverter 22 in the second flow path 66H.

[0070] Figure 6A An example of the operation of the cooling circuit of the cooling system 60 of this embodiment is shown. Aircraft 100 is operating its eight VTOL rotors 20 and ascending. The controller 69 operates pump 62L, and the coolant heated in the motors 21 of the VTOL rotors 20a and 20b (e.g., to 73.9°C) is delivered to radiator 61L via pipe 64L. The coolant cooled by radiator 61L (e.g., to 47.4°C) is then delivered to the motors 21 of the VTOL rotors 20a and 20b via pipe 65L at a flow rate of, for example, 8 liters / minute. At the same time, the pump 62H is operated by the control unit 69, and the coolant heated in the inverter 22 of the VTOL rotors 20a and 20b (for example, 76.4°C) is transported to the radiator 61H via the piping 64H, and the coolant cooled by the radiator 61H (for example, 63.2°C) is transported to the inverter 22 of the VTOL rotors 20a and 20b via the piping 65H at a flow rate of, for example, 10 liters / minute.

[0071] Here, two fans 61e operate, and airflow drawn in through inlet 70a (e.g., 37°C) first contacts heat sink 61L located on the inlet 70a side, undergoing heat exchange (e.g., 55.3°C) and heating the air. It then contacts heat sink 61H located on the outlet 70b side, undergoing heat exchange and further heating the air before being discharged through outlet 70b. At this point, heat sink 61L, which is first cooled by contact with the airflow and has a relatively low operating temperature, cools the low-temperature electrical component, namely, motor 21. Heat sink 61H, which is then cooled by contact with the airflow and has a relatively high operating temperature, cools the high-temperature electrical component, namely, inverter 22. This allows for efficient cooling of the electrical components, namely, motor 21 and inverter 22, of VTOL rotor 20.

[0072] Figure 6BAnother example of the operation of the cooling circuit of the cooling system 60 of this embodiment is shown. Assume that while the aircraft 100 is ascending with its eight VTOL rotors 20 in operation, the radiator 61L stops abnormally. Upon detecting the abnormality in the radiator 61L, the control unit 69 stops the pump 62L and opens and closes the four valves 67, opening the two third flow paths 66P and closing the first flow path 66L. The motor 21 is then connected in parallel with the inverter 22 in the second flow path 66H. Then, the controller 69 operates the pump 62H, and the coolant heated in the motors 21 and inverters 22 of the VTOL rotors 20a and 20b (e.g., to 85.4°C) is delivered to the radiator 61H via the pipe 64H. The coolant cooled by the radiator 61H (e.g., to 66.2°C) is delivered to the motors 21 and inverters 22 of the VTOL rotors 20a and 20b via the pipe 65H at flow rates of, for example, 8 liters / minute and 10 liters / minute, respectively. In this case, the flow rate of the coolant flowing through the radiator 61H increases, improving the heat transfer efficiency within the radiator. Therefore, even if a malfunction occurs in the radiator 61H, the temperature rise of the motors 21 and inverters 22 can be minimized.

[0073] Here, two fans 61e are working, and the air flow (for example, 37°C) sucked in from the inlet 70a passes through the stopped radiator 61L on the inlet 70a side without heat exchange, and then contacts the radiator 61H on the outlet 70b side to undergo heat exchange and be heated, and then discharged from the outlet 70b.

[0074] Meanwhile, while aircraft 100 was ascending by operating its eight VTOL rotors 20, radiator 61H stopped abnormally. Upon detecting the abnormality in radiator 61H, controller 69 stopped pump 62H and opened and closed four valves 67, opening two third flow paths 66P and closing second flow path 66H, thereby connecting inverter 22 in parallel with motor 21 in first flow path 66L. Controller 69 then operated pump 62L, causing coolant heated in motors 21 and inverter 22 of VTOL rotors 20a and 20b to be delivered to radiator 61L via pipe 64L. Coolant cooled by radiator 61L was then delivered to motors 21 and inverter 22 of VTOL rotors 20a and 20b via pipe 65L.

[0075] Here, the two fans 61e are working, and the air flow sucked in from the inlet 70a contacts the radiator 61L on the inlet 70a side and exchanges heat, thereby being heated. Then, without heat exchange, it passes through the radiator 61H on the outlet 70b side which is stopped, and is then discharged from the outlet 70b.

[0076] Therefore, the valve 67 is opened and closed and the inverter 22 is connected in parallel with the motor 21 in the first flow path 66L via the third flow path 66P, or the motor 21 is connected in parallel with the inverter 22 in the second flow path 66H, so that when a radiator or one of the radiator 61L and pump 62L and the radiator 61H and pump 62H fails, the radiator and pump on the other side can be used to cool the motor 21 and inverter 22 of the two VTOL rotors 20.

[0077] Similarly, the radiators 61 (two radiators 61L and 61H) disposed within the boom 18 between the rotating shafts 21a of the two VTOL rotors 20b and 20c may be used to form a cooling circuit for cooling the motors 21 and inverters 22 of the two VTOL rotors 20b and 20c. Furthermore, the radiators 61 (two radiators 61L and 61H) disposed within the boom 18 between the rotating shafts 21a of the two VTOL rotors 20c and 20d may be used to form a cooling circuit for cooling the motors 21 and inverters 22 of the two VTOL rotors 20c and 20d.

[0078] In addition, a cooling system having the same structure as the cooling system 60 may be provided to cool the electrical components of the cruise rotor 29 .

[0079] The cooling system 60 of this embodiment cools the VTOL rotor 20 by utilizing the airflow generated by the rotation of one or more blades 23 of the at least one VTOL rotor 20 in an aircraft 100 having at least one VTOL rotor 20 that generates thrust in the vertical direction during takeoff and landing. In this embodiment, two radiators 61L and 61H are accommodated between an inlet 70a and an outlet 70b of the boom 18 in a boom 18 that supports the one or more blades 23 above. Of the two radiators 61L and 61H, the radiator 61L located on the inlet 70a side and the radiator 61H located on the outlet 70b side are used to cool, respectively, a component with a low management temperature and a component with a high management temperature among the electrical components of the at least one VTOL rotor 20. Thus, through the cooling system 60, among the two radiators 61L and 61H accommodated in the boom 18 between the inlet 70a and the outlet 70b of the boom 18, the radiator 61L located on the inlet 70a side and first coming into contact with the airflow sucked in from the inlet 70a and being cooled, thereby having a lower operating temperature, cools and manages electrical components with low temperatures, such as the motor 21 of the VTOL rotor 20; and the radiator 61H located on the outlet 70b side and later coming into contact with the airflow passing through the radiator 61L and being cooled, thereby having a relatively higher operating temperature, cools and manages electrical components with high temperatures, such as the inverter 22, thereby enabling efficient cooling of the motor 21 and the inverter 22 of the VTOL rotor 20.

[0080] The aircraft 100 of the present embodiment includes: a fuselage 12; a front wing 14 and a rear wing 16 extending laterally from the fuselage 12 to generate lift during cruising; a boom 18 supported separately from the fuselage 12 by the front wing 14 and the rear wing 16 and extending in the fore-aft direction; at least one VTOL rotor 20 supported by the boom 18 and having one or more blades 23 for generating thrust in the vertical direction during takeoff and landing; and a cooling system 60 including two radiators 61L and 61H housed within the boom 18 and located between an inlet 70a and an outlet 70b of the boom 18. Of the two radiators 61L and 61H, the radiator 61L located on the inlet 70a side and the radiator 61H located on the outlet 70b side are used to cool, respectively, components with low and high managed temperatures among the electrical components of the at least one VTOL rotor. Thus, through the cooling system 60, among the two radiators 61L and 61H accommodated in the boom 18 between the inlet 70a and the outlet 70b of the boom 18, the radiator 61L located on the inlet 70a side and first coming into contact with the airflow sucked in from the inlet 70a and being cooled, thereby having a lower operating temperature, cools and manages electrical components with low temperatures, such as the motor 21 of the VTOL rotor 20; and the radiator 61H located on the outlet 70b side and later coming into contact with the airflow passing through the radiator 61L and being cooled, thereby having a relatively higher operating temperature, cools and manages electrical components with high temperatures, such as the inverter 22, thereby enabling efficient cooling of the motor 21 and the inverter 22 of the VTOL rotor 20.

[0081] Above, the present invention has been described using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious that those skilled in the art can make various changes or improvements to the above embodiments. In addition, according to the description of the protection scope of the present invention, it is obvious that the mode of carrying out such changes or improvements is also included in the technical scope of the present invention.

[0082] It should be noted that the order in which actions, processes, steps, and stages, etc., of the apparatus, system, program, and method described in the claims, specifications, and drawings may be performed in any order, unless otherwise expressly stated, such as "before," "prior to," or "before," and the output of a previous process is not used in a subsequent process. Even if the action flow in the claims, specifications, and drawings is described using the phrases "first," "next," and so on for convenience, it does not necessarily mean that the actions must be performed in that order.

[0083] [Explanation of Reference Numerals]

[0084] 12: Fuselage; 14: Front wing; 14a: Elevator; 16: Rear wing; 16a: Aileron; 16b: Vertical tail; 18: Boom; 18a: Skin; 18b: Rib; 18c: Beam; 18d, 18e: Space; 20, 20a, 20b, 20c, 20d: VTOL rotor; 21: Motor; 21a: Rotating shaft; 22: Inverter; 23: Blade; 29: Cruise rotor; 32: Pylons; 54: Pipes; 60: Cooling system; 61, 61H, 61L: Radiators; 61a1, 61a2: Tubes; 61 b1, 61b2: fins; 61c1, 61c2: upper tank; 61d1, 61d2: lower tank; 61e: fan; 61f: support member; 62L, 62H: pump; 63: coolant tank; 64H, 64L, 65H, 65L: piping; 67: valve; 69: control unit; 70: airflow guide structure; 70a: inlet; 70b: outlet; 71: upper structure; 71a: beam; 71b: recess; 72: lower structure; 72a: beam; 72b: recess; 100: aircraft; L: center axis; L 70 : Central axis.

Claims

1. An aircraft comprising: body; Wings extending laterally from the fuselage to generate lift during cruising; a boom supported by the wing body separately from the fuselage and extending in the front-rear direction; at least one rotor supported on the boom and having one or more blades for generating vertical thrust during takeoff and landing, and A cooling system comprises two radiators housed within the boom between an inlet and an outlet of the boom, wherein a first radiator located on the inlet side and a second radiator located on the outlet side of the two radiators are used to cool a low-management-temperature element and a high-management-temperature element of the at least one rotor, respectively.

2. The aircraft according to claim 1, wherein: The at least one rotor has a rotating device housed in the boom and configured to rotate the one or more blades, and a control device for controlling the rotating device. The element with a low management temperature and the element with a high management temperature are respectively the rotating device and the control device.

3. The aircraft according to claim 2, wherein: The at least one rotor includes two rotors, The cooling system uses the first radiator to cool the rotating device of each of the two rotors, and uses the second radiator to cool the control device of each of the two rotors.

4. An aircraft according to claim 2 or 3, wherein: The cooling system includes: a first flow path connecting the first radiator, the rotating device and a first pump supplying coolant to the rotating device; a second flow path connecting the second radiator, the control device and a second pump supplying coolant to the control device; a third flow path connecting the rotating device in the first flow path and the control device in the second flow path in parallel; and a valve that opens and closes the third flow path to the first flow path and the second flow path.

5. The aircraft according to claim 4, wherein: Also features: A control unit detects an abnormality in at least one of the first radiator, the first pump, the second radiator, and the second pump, and opens and closes the valve based on the detection result.

6. The aircraft according to any one of claims 1 to 5, wherein: The two radiators are arranged to overlap in a direction parallel to the rotation axis of the at least one rotor.

7. The aircraft according to any one of claims 1 to 6, wherein: The cooling system further includes a common fan for delivering airflow to the two radiators.

8. The aircraft according to any one of claims 1 to 7, wherein: The inlet is provided on the surface of the boom in an area below a rotation plane of the at least one rotor.

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