Aircraft

Abstract

To suppress decrease in flight performance.SOLUTION: An aircraft comprises: a shell; a thruster; an arm: a propeller; a baloon which is provided on the arm, is so configured as to be capable of telescopically movable, can expand in a direction approaching the propeller, and can contract in a direction separating from the propeller; a pressure regulating device; and a control device. A processor of the control device executes processing for: contracting the baloon when rotating the propeller; stopping the propeller so that the propeller extends in an extension direction of the arm when stopping the propeller; expanding the baloon and decreasing a clearance between the propeller and the baloon when stopping the propeller during flight.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an aircraft.

Background Art

[0002] For example, Patent Document 1 discloses an aircraft capable of vertical takeoff and landing. In such an aircraft of Patent Document 1, a guide cylinder in which a propeller (rotary blade) is accommodated is provided, a flexible bag body is provided at the inlet end of the guide cylinder, and by deforming the bag body, the flow of gas introduced into the rotary blade is adjusted.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the aircraft of Patent Document 1, the propeller is accommodated in the guide cylinder, but in some aircraft capable of vertical takeoff and landing, the propeller is exposed outside the fuselage. Also, in some aircraft capable of vertical takeoff and landing, in addition to the propeller for vertical takeoff and landing, a propulsion unit for propelling the fuselage is provided. In such an aircraft, after takeoff, the propeller may be stopped and the aircraft may fly only with the propulsion unit. If the propeller is stopped during flight, not only will the propeller no longer contribute to flight, but it may also increase the air resistance. Then, during flight with the propeller stopped, for example, flight performance such as flight speed and flight range may deteriorate.

[0005] Therefore, an object of the present invention is to provide an aircraft capable of suppressing a decrease in flight performance.

Means for Solving the Problems

[0006] To solve the above problems, an aircraft according to an embodiment of the present invention includes: a fuselage; a propulsion unit that propels the fuselage forward; an arm connected to the fuselage and extending in the front-rear direction; a propeller disposed above the arm and rotatably supported by the arm; a balloon provided on the arm, configured to be expandable and contractible, expandable in a direction approaching the propeller, and contractible in a direction away from the propeller; a pressure regulating device capable of expanding the balloon by feeding gas into the balloon and contracting the balloon by discharging gas from the inside of the balloon; a control device capable of controlling the propulsion unit, the propeller, and the pressure regulating device; and the control device includes: one or more processors; one or more memories connected to the processors; and the processor is configured to: when rotating the propeller, contract the balloon; when stopping the propeller, stop the propeller so that the propeller extends in the extending direction of the arm; when the propeller is stopped during flight, expand the balloon to reduce the gap between the propeller and the balloon; and execute processes including the above. The aircraft is as described above.

Advantages of the Invention

[0007] According to the present invention, it is possible to suppress a decrease in flight performance.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The specific dimensions, materials, numerical values, etc. shown in such embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same functions and configurations are denoted by the same reference numerals to omit redundant explanations, and elements not directly related to the present invention are not shown.

[0010] FIG. 1 is a schematic perspective view showing the configuration of the aircraft 1 according to the present embodiment. The aircraft 1 is configured to be capable of vertical takeoff and landing (VTOL). Further, the aircraft 1 may be a manned aircraft in which a pilot boards and operates, or an unmanned aircraft that flies by remote control or automatic control without a pilot on board. Note that the front, rear, left, right, up, and down of the aircraft 1 are defined as shown in FIG. 1.

[0011] The aircraft 1 includes a fuselage 10, wings 12, a propulsion unit 14, arms 16, a connection part 18, a propeller 20, a balloon 22, a pressure regulating device 24, and a control device 26.

[0012] The fuselage 10 extends in the front-rear direction. The wings 12 are formed in a plate shape and extend from the fuselage 10 in the left and right directions respectively.

[0013] The propulsion unit 14 is provided on the fuselage 10, for example, and generates a propulsion force that propels the fuselage 10 forward. By the generated propulsion force, the aircraft 1 is propelled, and lift is generated on the wings. The aircraft 1 can fly by the lift generated on the wings. In the example of FIG. 1, the propulsion unit 14 is configured as a propeller provided at the front end of the fuselage 10. Note that the propulsion unit 14 is not limited to the propeller in the example of FIG. 1, and may be configured as an engine provided, for example, at the rear of the fuselage 10 or on the wings 12.

[0014] The arms 16 are respectively arranged on the left and right sides of the fuselage 10. The left arm 16 is connected to the fuselage 10 via a connection part 18 extending leftward from the fuselage 10. The right arm 16 is connected to the fuselage 10 via a connection part 18 extending rightward from the fuselage 10. The arms 16 support the fuselage 10 when the aircraft 1 lands. Note that the right arm 16 and the left arm 16 may be collectively referred to simply as the arm 16. The arm 16 is formed in a substantially rod shape and extends in the front-rear direction.

[0015] The propeller 20 is arranged above the arm 16 and is exposed to the outside. The propeller 20 is rotatably supported by the arm 16. The propeller 20 can rotate around a vertical rotation axis. By rotating, the propeller 20 generates a lift force that moves the fuselage 10 and the arm 16 generally upward. The aircraft 1 can appropriately take off and land by the generated lift force.

[0016] In the example of FIG. 1, three propellers 20 are provided for one arm 16. The three propellers 20 on one arm 16 are arranged in a row while being spaced apart from each other along the extending direction of the arm 16, that is, the front-rear direction. Note that the number of propellers 20 provided on one arm 16 is not limited to the three illustrated in FIG. 1, and may be one, two, or four or more.

[0017] The balloon 22 is configured to be stretchable by an elastic material such as rubber, for example. The balloon 22 is provided on the arm 16. More specifically, the balloon 22 is provided at a position below the propeller 20 on the upper surface of the arm 16. The balloon 22 is provided, for example, at two positions, a frontward position and a rearward position, for each one propeller 20. Further, the balloon 22 is provided for all of the plurality of propellers 20.

[0018] The balloon 22 has a sealed internal space. The balloon 22 can be inflated in a direction approaching the propeller 20 when a gas such as air is fed into the internal space. Further, the balloon 22 can be contracted in a direction away from the propeller 20 when a gas such as air is discharged from the internal space. The inflation and contraction of the balloon 22 will be described in detail later.

[0019] Note that one balloon 22 may be provided across the frontward position and the rearward position for one propeller. Further, the balloon 22 is not limited to the mode of being provided for each propeller 20. For example, a common balloon 22 may be provided across a plurality of propellers 20. In that case, for example, a common balloon 22 may be provided across the three propellers 20, such as providing one balloon 22 across the front end portion to the rear end portion of the arm 16. Further, for example, a common balloon 22 may be provided across two adjacent propellers 20 among the three propellers 20, and a separate and independent balloon 22 may be provided for the other one propeller 20.

[0020] The pressure regulating device 24 is, for example, an electric air pump or the like. The pressure regulating device 24 is provided on the arm 16. Also, the pressure regulating device 24 is provided for each arm 16. The pressure regulating device 24 is connected to the balloon 22 and is configured to be able to send and discharge a gas such as air to and from the balloon 22.

[0021] That is, the pressure regulating device 24 can inflate the balloon 22 by sending a gas into the inside of the balloon 22, and can contract the balloon 22 by discharging the gas from the inside of the balloon 22.

[0022] Hereinafter, the state in which the balloon is contracted may be referred to as the contracted state. Also, the state in which the balloon is inflated may be referred to as the inflated state.

[0023] The control device 26 is provided, for example, on the fuselage 10. The control device 26 is configured to be able to control the propulsion unit 14, the propeller 20, and the pressure regulating device 24.

[0024] FIG. 2 is a block diagram showing an example of the configuration of the control device 26. The control device 26 includes one or more processors 30 and one or more memories 32 connected to the processors 30. The memory 32 includes a ROM in which programs and the like are stored and a RAM as a work area. The processor 30 executes various processes in cooperation with the programs included in the memory 32. The processor 30 functions as an airframe control unit 40 that controls the propulsion unit 14, the propeller 20, and the pressure regulating device 24 by executing a program.

[0025] The airframe control unit 40 can vertically take off and land the aircraft 1 by rotating the propeller 20 during takeoff and landing. Hereinafter, the state in which the propeller 20 is rotating may be referred to as the rotating state with respect to the propeller 20. When the airframe control unit 40 rotates the propeller 20, it makes the balloon 22 in the contracted state. The contracted balloon 22 is separated from the propeller 20 and does not contact the propeller 20.

[0026] In addition, when the airframe control unit 40 operates the propulsion unit 14 to perform propulsion, that is, during flight, the rotation of the propeller 20 can be stopped. When the airframe control unit 40 stops the propeller 20 during flight, as shown in FIG. 1, the propeller 20 is stopped so as to extend in the extending direction of the arm 16, that is, in the longitudinal direction of the aircraft 1. Hereinafter, the state in which the propeller 20 is stopped may be referred to as a stopped state with respect to the propeller 20.

[0027] The aircraft 1 may be provided with a positioning mechanism for adjusting the stop position of the propeller 20. In that case, when the airframe control unit 40 stops the propeller 20, the extending direction of the propeller 20 at the time of stop may be adjusted by the positioning mechanism. As the positioning mechanism, for example, a guide member may be provided at the proximal end portion of the rotation axis of the propeller 20, and the angle of the rotation axis may be guided to a predetermined angle by the guide member and fixed. Note that the positioning mechanism is not limited to the example shown, and may have any configuration capable of adjusting the stop position of the propeller 20. Further, the airframe control unit 40 may adjust the stop position of the propeller 20 by controlling the rotation angle of the motor that rotates the propeller 20.

[0028] In addition, when the airframe control unit 40 stops the propeller 20 during flight, the balloon 22 is inflated, and at least the gap between the propeller 20 and the balloon 22 is reduced as compared with when the balloon 22 is in a contracted state. When the gap between the propeller 20 and the balloon 22 is reduced, it becomes difficult for the propeller 20 to receive air as compared with when the balloon is in a contracted state, and thus the air resistance of the propeller 20 during flight is reduced. Hereinafter, the contraction and expansion of the balloon 22 will be described in detail.

[0029] FIG. 3 is a partially enlarged side view of the aircraft 1 as seen from the side with the portion around the propeller 20 enlarged in a state where the balloon 22 is contracted. FIG. 4 is a partially enlarged front view of the aircraft 1 as seen from the front with the portion around the propeller 20 enlarged in a state where the balloon 22 is contracted.

[0030] As shown in FIGS. 3 and 4, the propeller 20 has, for example, two blades 48. The propeller 20 is connected to a motor 50 that rotates each blade 48 of the propeller 20. The motor 50 is connected on the arm 16. The dashed-dotted line C1 in FIGS. 3 and 4 indicates the rotation axis of the motor 50, that is, the rotation axis of the propeller 20. The blade 48 extends in a radial direction perpendicular to the rotation axis of the motor 50 from the rotation axis of the motor 50. The propeller 20 rotates, for example, in the counterclockwise direction when viewed from directly above the propeller 20.

[0031] As shown in FIG. 3, the balloons 22 are provided, for example, on the upper surface of the arm 16 and below the propeller 20, at positions in front of and behind the motor 50, respectively. In FIG. 3, an example is shown in which separate balloons 22 are provided at a position in front of the motor 50 and a position behind the motor 50, but one integrated balloon 22 may be provided by integrating the balloon 22 in front of the motor 50 and the balloon 22 behind the motor 50.

[0032] As shown in FIG. 3, the pressure regulating device 24 is built into the arm 16. The pressure regulating device 24 is connected to the balloon 22 through a pipe 52 provided inside the arm 16. The pipe 52 branches and is connected, for example, from the pressure regulating device 24 to all the balloons 22 on the arm 16. The pressure regulating device 24 commonly supplies and discharges gas to and from the plurality of balloons 22 through the pipe 52.

[0033] As shown in FIG. 3, the balloon 22 in front of the motor 50 is provided such that its front end is located in front of the front end of the propeller 20 in the stopped state. The balloon 22 behind the motor 50 is provided such that its rear end is located behind the rear end of the propeller 20 in the stopped state.

[0034] As shown in FIG. 4, it is preferable that the balloon 22 is provided such that the width dimension in the left-right direction is equal to or greater than the width dimension in the left-right direction of the propeller 20 in the stopped state.

[0035] As shown in FIG. 4, in the propeller 20, each blade 48 is connected to the motor 50 in a posture inclined with respect to a reference plane which is a plane perpendicular to the vertical rotation axis of the propeller 20. More specifically, in the blade 48 of the propeller 20, the portion on the fuselage 10 side (that is, “left” as shown in FIG. 4) is located above the portion on the opposite side of the fuselage 10 (that is, “right” as shown in FIG. 4), and is inclined so as to descend as it proceeds in the direction away from the fuselage 10. In other words, the blade 48 is inclined in the rotation direction of the propeller 20 with respect to the reference plane so as to rise as it proceeds in the rotation direction of the propeller 20.

[0036] Also, as shown in FIG. 4, the balloon 22 in the contracted state has a relatively flat shape, and the lower surface of the balloon 22 is connected to the upper surface of the arm 16. Further, the upper surface 54 of the balloon 22 in the contracted state is inclined with respect to the above-described reference plane in the same direction as the inclination direction of the blade 48 of the propeller 20 at a position facing the upper surface 54. More specifically, in the upper surface 54 of the balloon 22, the portion on the fuselage 10 side (that is, “left” as shown in FIG. 4) is located above the portion on the opposite side of the fuselage 10 (that is, “right” as shown in FIG. 4), and is inclined so as to descend as it proceeds in the direction away from the fuselage 10.

[0037] Thereby, when the propeller 20 rotates, most of the air flowing below the propeller 20 flows along the inclined upper surface 54 of the balloon 22 in the downward direction of the upper surface 54, as shown by the solid arrow A1 in FIG. 4. Then, as shown by the white arrow A3 in FIG. 4, a thrust deflection flow in the downward direction and in the direction away from the fuselage 10 can be generated. In the aircraft 1, as a reaction of the generated thrust deflection flow, a lateral force substantially equivalent to that obtained by inclining the rotation axis of the motor 50 is generated. That is, in the aircraft 1, this lateral force can generate a body direction control force during takeoff and landing. For example, in the aircraft 1, when the aircraft is rotated in the yaw direction when receiving wind or the like, it can be appropriately suppressed by the lateral force as a reaction of the thrust deflection flow caused by the inclined upper surface 54 of the balloon 22.

[0038] FIG. 5 is a partially enlarged side view of the aircraft 1 as seen from the side, with the portion around the propeller 20 enlarged in the state where the balloon 22 is inflated. FIG. 6 is a partially enlarged front view of the aircraft 1 as seen from the front, with the portion around the propeller 20 enlarged in the state where the balloon 22 is inflated.

[0039] The airframe control unit 40 preferably inflates the balloon 22 until the upper surface 54 of the balloon 22 contacts the lower surface of the propeller 20.

[0040] More specifically, as shown in FIGS. 5 and 6, when the balloon 22 is in an inflated state, the balloon 22 comes into contact with the propeller 20, and at least a part of the front end face and at least a part of the side face of the stationary propeller 20 are preferably embedded in the balloon 22.

[0041] Thereby, the propeller 20 is protected by the balloon 22, and the area of the surface of the propeller 20 that receives air during flight can be reduced. And the balloon 22 acts so as to divert the air received during flight. Therefore, in the aircraft 1, the air resistance of the propeller 20 during flight can be reduced. As a result, in the aircraft 1, it is possible to suppress a decrease in flight performance such as flight speed and cruising range, for example.

[0042] Note that the degree of contact between the balloon 22 and the propeller 20 is not limited to the mode until at least a part of the front end face and at least a part of the side face of the stationary propeller 20 are embedded in the balloon 22. For example, although at least a part of the front end face and at least a part of the side face of the stationary propeller 20 do not reach the state of being embedded in the balloon 22, the balloon 22 may be inflated to such an extent that it contacts at least a part of the lower surface of the propeller 20. Also in this mode, it is possible to make it difficult for the propeller 20 to receive air and to suppress a decrease in flight performance.

[0043] Also, as shown in FIG. 5, when the balloon 22 is in an inflated state, it is preferable that the balloon 22 is in contact with the propeller 20, and the inflated balloon 22 and the stationary propeller 20 are integrally formed in a streamlined shape.

[0044] Thereby, the balloon 22 and the propeller 20 integrally formed in a streamlined shape act to more smoothly receive the air received during flight. As a result, in the aircraft 1, the air resistance of the propeller 20 during flight can be further reduced, and a decrease in flight performance can be suppressed.

[0045] Also, in FIGS. 5 and 6, the inflated balloon 22 was in contact with the propeller 20. However, the mode of inflating the balloon 22 is not limited to the mode of inflating the balloon 22 until it contacts the propeller 20. At least, compared with the contracted state, in the inflated state, it is sufficient that the gap between the propeller 20 and the balloon 22 is reduced, and the balloon 22 does not have to be in contact with the propeller 20. By reducing the gap between the propeller 20 and the balloon 22, it is possible to make it difficult for the propeller 20 to receive air, and in this mode as well, it is possible to suppress a decrease in flight performance.

[0046] Also, although not shown, the aircraft 1 may have an internal pressure sensor capable of detecting the pressure in the internal space of the balloon 22 and an external pressure sensor capable of detecting the pressure outside the balloon 22, that is, the atmospheric pressure. The control device 26 may control the amount of gas fed into the balloon 22 by the pressure regulating device 24, that is, the degree of inflation of the balloon 22, based on the differential pressure between the external pressure detected by the external pressure sensor and the internal pressure detected by the internal pressure sensor.

[0047] For example, when the pressure regulating device 24 is feeding gas into the balloon 22 to inflate the balloon 22, when the differential pressure between the internal pressure and the external pressure of the balloon 22 reaches a predetermined differential pressure, the feeding of the gas may be terminated to complete the inflation of the balloon 22. The predetermined differential pressure is arbitrarily set, for example, the differential pressure when the balloon 22 contacts the propeller 20, or the differential pressure when the propeller 20 and the balloon 22 become streamlined. Thereby, in the aircraft 1, it becomes possible to appropriately inflate the balloon 22 without directly detecting that the balloon 22 has contacted the propeller 20.

[0048] Next, an example of a series of operations in the aircraft 1 will be described. When the aircraft 1 is landing, the propeller 20 is in a stopped state and the balloon 22 is in a contracted state. When the aircraft 1 takes off, while the balloon 22 maintains the contracted state, the propeller 20 becomes a rotating state. Thereby, the aircraft 1 takes off.

[0049] After takeoff, the propulsion unit starts operating, and the aircraft 1 propels toward the destination. After the propulsion unit starts operating, when the aircraft 1 accelerates to a predetermined speed and lift capable of maintaining the flight of the aircraft 1 is generated on the wing 12, the rotation of the propeller 20 is stopped. When the propeller 20 thus becomes a stopped state during flight, the balloon 22 is set in an inflated state. Thereby, the air resistance of the propeller 20 is reduced.

[0050] When approaching the planned landing point, the balloon 22 is contracted. Thereafter, the rotation of the propeller 20 is started, and the landing operation is started. When the landing operation ends, the propeller 20 becomes a stopped state.

[0051] FIG. 7 is a flowchart for explaining the operation flow of the control device 26. The airframe control unit 40 repeatedly executes the process of FIG. 7, for example, every time a predetermined interrupt timing that visits at a predetermined cycle arrives.

[0052] When a predetermined interruption timing arrives, the airframe control unit 40 determines whether the conditions for starting the rotation of the propeller 20, that is, whether the propeller rotation start conditions are satisfied (S10). For example, when receiving an instruction to start takeoff or landing by the pilot's operation or remote operation, the airframe control unit 40 may determine that the propeller rotation start conditions are satisfied. Further, for example, when it reaches a predetermined timing to start takeoff or landing by automatic control, the airframe control unit 40 may determine that the propeller rotation start conditions are satisfied.

[0053] When it is determined that the propeller rotation start conditions are satisfied (YES in S10), the airframe control unit 40 determines whether the current state of the balloon 22 is a contracted state (S11). For example, the airframe control unit 40 may determine whether the balloon 22 is in a contracted state based on the differential pressure between the internal pressure and the external pressure of the balloon 22.

[0054] When it is determined that the balloon 22 is not in a contracted state, that is, the balloon 22 is in an inflated state (NO in S11), the airframe control unit 40 causes the pressure regulating device 24 to send out gas from the internal space of the balloon 22 to contract the balloon 22 (S12). After contracting the balloon 22, the airframe control unit 40 drives the motor 50 to rotate the propeller 20 (S13). Thereby, in the aircraft 1, for example, when shifting from a propelling state to a landing operation, the balloon 22 can start the rotation of the propeller 20 without hindering the rotation of the propeller 20.

[0055] When it is determined that the balloon 22 is in a contracted state, that is, the balloon 22 is not in an inflated state (YES in S11), since there is no need to further contract the balloon 22, the airframe control unit 40 directly drives the motor 50 to rotate the propeller 20 (S13) and ends a series of processes. Thereby, in the aircraft 1, for example, when shifting from a landing state to a takeoff operation, the rotation of the propeller 20 can be started without delay.

[0056] Also, in step S10, if it is determined that the propeller rotation start condition is not satisfied (NO in S10), the airframe control unit 40 proceeds to the process of step S14.

[0057] In step S14, the airframe control unit 40 determines whether the condition for starting the stop of the rotating propeller 20, that is, whether the propeller stop start condition is satisfied (S14). For example, the airframe control unit 40 may determine that the propeller stop start condition is satisfied when it receives an instruction to start propulsion after takeoff or an instruction to end the landing operation by the pilot's operation or remote operation. Also, the airframe control unit 40 may determine that the propeller stop start condition is satisfied when, for example, it reaches a predetermined timing to start propulsion after takeoff or a predetermined timing to end the landing operation when the landing is detected, by automatic control.

[0058] If it is determined that the propeller stop start condition is satisfied (YES in S14), the airframe control unit 40 stops the motor 50 to stop the rotation of the propeller 20 (S15). At this time, the airframe control unit 40 controls the motor 50 so that the propeller 20 stops in a posture where the propeller 20 extends in the extending direction of the arm 16, thereby controlling the posture of the propeller 20 at the time of stop.

[0059] After the propeller 20 stops, the airframe control unit 40 determines whether the aircraft 1 is in flight at the current time (S16). For example, the airframe control unit 40 may determine that it is in flight when the propulsion unit 14 is operating.

[0060] When it is determined that the aircraft is in flight (YES in S16), the airframe control unit 40 causes the pressure regulating device 24 to send gas into the balloon 22 to inflate the balloon 22 (S16), and ends a series of processes. As the balloon 22 inflates, the balloon 22 comes into contact with the propeller 20, and in the aircraft 1, the balloon 22 and the propeller 20 are integrally formed in a streamlined shape. Thereby, in the aircraft 1, for example, even if the propeller 20 is stopped after takeoff and the aircraft transitions to a propulsion operation, the air resistance of the propeller 20 during flight is reduced by the inflated balloon 22, and a decrease in flight performance can be suppressed.

[0061] On the other hand, when it is determined that the aircraft is not in flight (NO in S16), the airframe control unit 40 simply ends a series of processes. In this case, the balloon 22 remains in a contracted state without being inflated. For example, when the landing operation is completed and the propeller 20 stops, since the aircraft 1 is in a landed state, there is no need to reduce the air resistance of the propeller 20. Therefore, in such a case, the balloon 22 is maintained in a contracted state without being inflated.

[0062] Also, in step S14, when it is determined that the propeller stop start condition is not satisfied (NO in S14), the airframe control unit 40 simply ends a series of processes.

[0063] In this way, the airframe control unit 40 controls the contraction and inflation of the balloon 22 according to the start of rotation and the start of stop of the propeller 20.

[0064] As described above, the aircraft 1 of the present embodiment includes a balloon 22 provided on the arm 16, configured to be telescopic, expandable in a direction approaching the propeller 20, and contractible in a direction away from the propeller 20. In the aircraft 1 of the present embodiment, when the propeller 20 is rotated, the balloon 22 is put in a contracted state. In the aircraft 1 of the present embodiment, when the propeller 20 is stopped, the propeller 20 is stopped so that the propeller 20 extends in the extending direction of the arm 16. In the aircraft 1 of the present embodiment, when the propeller 20 is stopped during flight, the balloon 22 is put in an inflated state to reduce the gap between the propeller 20 and the balloon 22.

[0065] Thereby, in the aircraft 1 of the present embodiment, even when the propeller 20 is stopped during flight, the air resistance of the propeller 20 can be reduced by the inflated balloon 22. Therefore, in the aircraft 1 of the present embodiment, it is possible to suppress a decrease in flight performance such as flight speed and endurance.

[0066] Further, in the aircraft 1 of the present embodiment, since the balloon 22 is in a contracted state when the propeller 20 is rotated, the rotation of the propeller 20 is not inhibited by the balloon 22.

[0067] As described above, the embodiments of the present invention have been described with reference to the accompanying drawings. Needless to say, the present invention is not limited to such embodiments. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it is naturally understood that they also belong to the technical scope of the present invention.

Explanation of Reference Numerals

[0068] 1 Aircraft 10 Fuselage 14 Propulsion Device 16 Arm 20 Propeller 22 Balloon 24 Pressure Regulating Device 26 Control Device 30 Processor 32 memory 48 blades 54 upper surface

Claims

1. A fuselage, a propulsion device for propelling the fuselage forward, an arm connected to the fuselage and extending in the front-rear direction, a propeller disposed above the arm and rotatably supported by the arm, a balloon provided on the arm, configured to be extendable and contractible, expandable in a direction approaching the propeller, and contractible in a direction away from the propeller, a pressure regulating device capable of expanding the balloon by feeding gas into the balloon and contracting the balloon by discharging gas from the inside of the balloon, a control device capable of controlling the propulsion device, the propeller, and the pressure regulating device, comprising: The control device has one or more processors, and one or more memories connected to the processors, and the processor when rotating the propeller, contracts the balloon, when stopping the propeller, stops the propeller so that the propeller extends in the extending direction of the arm, when the propeller is stopped during flight, expands the balloon and reduces the gap between the propeller and the balloon, An aircraft that executes a process including the above.

2. The aircraft according to claim 1, wherein when the balloon is in an inflated state, the balloon is in contact with the propeller, and at least a part of the front end face and at least a part of the side face of the propeller in a stopped state are embedded in the balloon.

3. The aircraft according to claim 1, wherein when the balloon is in an inflated state, the inflated balloon and the propeller in a stopped state are integrally formed in a streamlined shape.

4. The blades of the propeller are inclined with respect to a reference plane that is a plane perpendicular to the rotation axis of the propeller, and the upper surface of the balloon in a contracted state is inclined with respect to the reference plane in the same direction as the inclination direction of the blades of the propeller. The aircraft according to claim 1.

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