Multicopter

Abstract

To develop a multicopter having a generator driven by an engine, and a rotary vane rotating by a motor and generating lifting power, which is a multicopter capable of starting engine easily.SOLUTION: In a multicopter having a generator 11 driven by an engine 135, and a rotary vane rotating by a motor and generating lifting power, a rotational axis 150 of the engine 135 is arranged toward an approximately vertical direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to multicopters, commonly referred to as "drones." [Background technology]

[0002] Multicopters with multiple rotors (propellers) and capable of vertical takeoff and landing are well known. Multicopters were initially sold as toys, but they have gradually become more sophisticated and are now being used for commercial purposes such as aerial photography and transporting goods. Multicopters capable of manned flight are also being developed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-129713 Summary of the Invention [Problem to be solved by the invention]

[0004] The rotors of a multicopters are driven by a motor. Therefore, multicopters are equipped with a storage battery to drive the motor. In conventional multicopters, the motor is rotated by electricity stored in the storage battery, enabling them to fly. Therefore, the range of conventional multicopters depends on the capacity of the storage battery. As a way to extend the range of multicopters, the inventors invented a system in which a multicopter is equipped with a generator and an engine to drive the generator, generating electricity during flight and using that electricity to drive the rotors (propellers).

[0005] This type of multicopters requires the engine to be started at the start of flight. For this reason, engines equipped with starter motors and engines equipped with recoil starters are known. However, starter motors are quite heavy. Recoil starters are lighter than starter motors, but starter motors and recoil starters are only used for starting the engine, not during flight. In principle, multicopters generate buoyancy solely through the airflow generated by the rotors, so there is a need to reduce the weight of the aircraft. The present invention focuses on this problem and aims to develop a multicopter that has a generator driven by an engine and rotors that rotate using a motor to generate lift, and that has an engine that is easy to start. [Means for solving the problem]

[0006] An embodiment for solving the above-mentioned problems is a multicopter having a generator driven by an engine and rotors that rotate by a motor to generate lift, characterized in that the rotation axis of the engine is arranged to face generally in a vertical direction.

[0007] The phrase "generally facing up and down" does not necessarily mean a vertical direction, but means that when the multicopter is placed in a horizontal position, the extension of the rotation axis faces generally up and down. For example, the angle between the rotation axis and the vertical line is within a range of 45 degrees. The type of engine is not limited, and known engines such as reciprocating engines, rotary engines, turbine engines, jet engines, etc. The engine may be water-cooled or air-cooled. The multicopter of this embodiment has a generator, and electricity generated by the generator can be supplied to the motor, so the multicopter of this embodiment has a long cruising range. In this type of multicopter, the engine's rotation axis is positioned facing up and down, so when starting the engine using an external device, the tool can be pressed against it from above, making the multicopter less likely to move due to external forces and easier to start.

[0008] In the above-described aspect, it is desirable that the end of the rotary shaft or a member that rotates integrally with the rotary shaft can be exposed.

[0009] Being exposable refers to a state in which an instrument or the like can be connected from the outside, and the end of the rotating shaft or a member that rotates integrally with the rotating shaft may be provided in a recessed position. According to this aspect, the end of the rotary shaft or the member that rotates integrally with the rotary shaft can be exposed, making it easy to connect the device.

[0010] In the above-mentioned aspect, it is desirable that the turbine has a main body portion, a plurality of rotors attached to the main body portion, the main body portion has a ring-shaped support frame portion that is air permeable in the vertical direction, the engine and the generator are mounted on the support frame portion, and the generator is located below the engine.

[0011] The multicopter of this embodiment has a circular support frame that is air permeable in the vertical direction, and the engine and generator are located on the support frame, so the engine and generator are placed in a well-ventilated area, resulting in high cooling efficiency.

[0012] In each of the above aspects, it is desirable that the rotor has a main body portion, a plurality of rotor blades are attached to the main body portion, and the support frame portion itself has a hollow portion inside, and that the hollow portion can store fuel.

[0013] The multicopter of this embodiment does not require a separate fuel tank, allowing for efficient use of space, thereby increasing the area for mounting equipment and goods, and reducing the weight required for the fuel tank. The multicopter of this embodiment can make effective use of space and can be made smaller overall. [Effects of the Invention]

[0014] The multicopter of the present invention has an easy-to-start engine. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a multicopter according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the multicopter of FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view of the multicopter of FIG. 1. [Figure 4] 2 is a cross-sectional view showing the state when the support frame portion of the multicopter in FIG. 1 is separated into an annular structure portion and an equipment support portion. [Figure 5] FIG. 5 is a cross-sectional view in which the power generation unit is removed from the cross-sectional view of FIG. 4. [Figure 6] FIG. 2 is an exploded perspective view of the annular structure of the support frame of the multicopter of FIG. 1. [Figure 7] FIG. 2 is an exploded perspective view of a rib portion and a rotor portion of the multicopter of FIG. 1. [Figure 8] FIG. 2 is a perspective view of a power generation unit of the multicopter of FIG. 1. [Figure 9] FIG. 2 is an explanatory diagram for explaining the attitude of the power generation unit, conceptually illustrating the upper part of the multicopter in FIG. 1 and the motor for starting the engine. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described. The multicopter 100 of this embodiment has rotors 2, similar to known ones, and the rotors 2 are rotated by a motor 20. The multicopter 100 of this embodiment is equipped with a generator 11 and an engine 135. The generator 11 is integrated with the engine 135 and can generate electricity by driving the engine 135. The engine 135 is rotated by fuel supplied from a fuel tank. The generator 11 is connected to a storage battery (not shown), and generates electricity during flight, which is then supplied to the motor 20 directly or via the storage battery. Therefore, the multicopter 100 of this embodiment has a long cruising range.

[0017] In the multicopter 100 of this embodiment, a main body 103 has an annular support frame 105. In the space surrounded by the support frame 105, a generator 11 and an engine 135 are disposed.

[0018] 3, the multicopter 100 has a hollow portion 200 that serves as a fuel tank provided in a part of the support frame portion 105 itself. That is, the hollow portion 200 is located inside the wall at the lower side of the portion that constitutes the outer wall of the support frame portion 105, and the hollow portion 200 serves as the fuel tank. The multicopter 100 of this embodiment has a main body 103 and four rotors 2. The rotors 2 are rotated by a motor 20. As shown in FIG. 1, the main body 103 has a support frame 105, a rib 106, a control device mounting portion 107, and legs 12.

[0019] The rib portion 106 is molded separately from the support frame portion 105 and attached to the support frame portion 105 later. As shown in FIG. 7, the rib portion 106 is formed by integrally molding a fixing portion 160, an arm portion 161, and a seat portion 162 that are attached to the support frame portion 105. The seat portion 162 is a portion where the motor 20 that drives the rotor 2 is fixed. The seat portion 162 is made larger than the arm portion 161, and has a smooth upper surface that forms a mounting surface. Holes 165 for inserting screws are provided in the surface of the mounting surface.

[0020] 3, the control device mounting part 107 is attached to the lower part of the support frame part 105 at a distance by a hard hanging member 166 such as a piano wire. There is a gap between the support frame part 105 and the control device mounting part 107. The control device mounting part 107 is equipped with communication devices, an attitude control device, etc.

[0021] The support frame 105 has an annular structure 111 and a support structure 102. The annular structure 111 has an annular external shape, and has a hollow portion 108 in the center that is connected vertically as shown in Figure 3. The power generation unit 110 is built into the area including the hollow portion 108. In this embodiment, a hollow portion 200 is formed in a part of the support frame portion 105 itself, and the hollow portion 200 functions as a fuel tank. It is recommended that the inner surface of the hollow portion 200 be coated with a soft resin or lined with a soft resin. Lining the interior with soft resin can prevent fuel from leaking when a crack occurs in the support frame portion 105 due to an impact. In addition, incorporating a fuel bag (bladder) made of oil-resistant soft resin (such as rubber) into hollow portion 200 and creating a structure that prevents fuel from coming into direct contact with support frame portion 105 is also effective in preventing fuel leakage.

[0022] The annular structural portion 111 of the support frame portion 105 is a portion formed in an endless annular shape. In this embodiment, the planar shape of the annular structural portion 111 is circular as shown in Fig. 1. The annular structural portion 111 is made of a lightweight and highly rigid material such as carbon fiber.

[0023] As shown in FIG. 2, the annular structure 111 is made up of an outer shell member 112 and an inner lid member (lid member) 113. The outer shell member 112 has an outer cylindrical outer peripheral wall portion 115, an inner cylindrical inner peripheral wall portion 117, and a bottom wall portion 118 connecting the lower ends of the two. As shown in Figures 4 to 6, the outer shell member 112 has an annular groove portion 120 that surrounds the inner circumference of the outer peripheral wall portion 115. The groove portion 120 has an open upper surface. A large opening 121 is provided in the center of the outer shell member 112. When viewed alone, the outer peripheral wall portion 115 has a circular cross section and is cylindrical. The inner peripheral wall portion 117 also has a circular planar cross section and is cylindrical. The inner peripheral wall portion 117 is concentric with the outer peripheral wall portion 115 and stands in an area surrounded by the outer peripheral wall portion 115. The inner peripheral wall portion 117 is shorter in height than the outer peripheral wall portion 115 and has an inner flange 122 formed at its upper end.

[0024] Rib attachment portions 140 are provided at four locations on the side surface of the outer peripheral wall portion 115. The rib attachment portions 140 are used to secure the ends of the rib portions 106, and have fitting portions 158. The fitting portions 158 are in the form of vertical grooves, and the openings of the vertical grooves are narrowed to form slits.

[0025] The inner lid member 113 is a short, cylindrical member that is half-closed and has an inner flange 125 on one end side. The inner lid member 113 has a cylindrical inner cylinder portion 123 that is inserted snugly into the inner wall of the outer peripheral wall portion 115, and an inner flange 125 is provided at one end of the inner cylinder portion 123. The inner diameter of the inner flange 125 of the inner lid member 113 is approximately equal to the inner diameter of the inner flange 122 of the inner peripheral wall portion 117 of the outer shell member 112.

[0026] The annular structure 111 is formed by fitting an inner lid member 113 into a recessed portion of an outer shell member 112 . That is, the inner cover member 113 is inserted into the outer casing member 112, the inner flange 122 of the outer casing member 112 and the center side surface of the inner flange 125 of the inner cover member 113 are aligned, and the two are joined together with a fastening element such as a screw 145. The opening on the top surface of the groove 120 of the outer shell member 112 is closed by the inner flange 125 of the inner lid member 113 . As a result, an annular hollow portion 200 is formed that is surrounded by the groove portion 120 of the outer shell member 112 and the inner flange 125 at one end of the inner cylindrical portion 123. The annular hollow portion 200 functions as a fuel tank. In this embodiment, there is a fuel supply port 86 that communicates with the hollow portion 200, and a plug 87 is attached to the fuel supply port 86. The fuel supply port 86 is provided on the outer surface of the support frame portion 105.

[0027] The annular structure 111 is a part of the support frame 105 and is a member that constitutes its outer wall. In this embodiment, the lower side of the support frame 105 bulges inward, and the inside of this bulging part becomes the hollow part 200 described above, where fuel is stored.

[0028] The upper region within the annular structural portion 111 forms a large cylindrical cavity 137. Furthermore, within the annular structural portion 111, a small cavity 138 is formed by the inner peripheral wall portion 117. The upper side of the large cavity 137 is open. The lower side of the large cavity 137 communicates with the lower side via the small cavity 138 formed by the inner peripheral wall portion 117. In this way, within the annular structural portion 111 of the support frame portion 105, there is a cavity 108 formed by the large cavity 137 and the small cavity 138.

[0029] The support structure 102 includes an intermediate closure member 146 , a support member 126 and an outer closure member 127 . Intermediate cover member 146 has an annular support frame portion 155 and a hanging portion 156 hanging down from the inner edge side of support frame portion 155, with inner flange 157 formed at the lower end of hanging portion 156. Intermediate cover member 146 penetrates in the vertical direction. The support frame 155 is provided with four small lid portions 147 .

[0030] The support member 126 has an upper annular member 130 and a lower annular member 131, which are connected by a connecting member 132. The connecting member 132 is made up of a plurality of plate-like portions 133, and large gaps 141 are formed between the plate-like portions 133.

[0031] The outer lid member 127 is a dome-shaped lid having a plurality of openings. That is, the outer lid member 127 has an opening 142 in the center and also has openings 143 on the sides.

[0032] The support structure 102 is formed by joining the intermediate cover member 146, the support member 126 and the outer cover member 127 with screws or the like. In this embodiment, as shown in Fig. 5, the upper annular member 130 of the support member 126 is connected to the support frame portion 155 of the intermediate cover member 146 by a fastening element such as a screw 167, and the connecting member 132 and the lower annular member 131 of the support member 126 are inserted into the opening of the intermediate cover member 146. An outer cover member 127 is attached onto the support member 126 .

[0033] In this embodiment, the intermediate cover member 146 of the support structure 102 is attached to the outer peripheral wall portion 115 of the annular structure 111, and the connecting member 132 and the lower annular member 131 of the support member 126 are arranged within a space surrounded by the outer shell member 112 of the support frame portion 105. The lower annular member 131 and the adjacent connecting member 132 are inserted into a small cavity 138 defined by the inner peripheral wall portion 117 .

[0034] The power generation unit 110 is an integrated unit of an engine 135 and its accessories, and a generator 11. The engine 135 is equipped with an injector (not shown), an intake filter 51, and a muffler (not shown). Engine 135 is a single-cylinder, air-cooled, two-stroke engine. One end of crankshaft (rotating shaft) 150 of engine 135 is directly connected to generator 11. As shown in FIGS. 8 and 9, a model airplane spinner cone 151 is attached to one end of crankshaft (rotating shaft) 150. Spinner cone 151 rotates integrally with crankshaft (rotating shaft) 150 of engine 135.

[0035] In this embodiment, the power generation unit 110 is arranged in the area formed between the support member 126 and the outer cover member 127, with the crankshaft (rotating shaft) 150 facing up and down and the generator 11 on the lower side, as shown in Figures 3, 4, and 9. In this embodiment, as shown in Figures 3 and 4, the generator 11 is connected to the lower annular member 131 of the support member 126. As shown in Figure 1, a spinner cone 151 attached to the other end of the crankshaft (rotating shaft 150) protrudes to the outside from an opening 142 in the center of the outer lid member 127. The intake filter 51 also protrudes to the outside from an opening 143.

[0036] The power generation unit 110 has the entire generator 11 and part of the engine 135 located in the area surrounded by the annular portion of the annular structure 111, and another part of the engine 135 located in the area above the area surrounded by the annular portion of the annular structure 111.

[0037] When starting the power generating unit 110, a motor 153 for starting the engine is connected to the spinner cone 151 protruding outward, as shown in Figure 9. Then, by rotating the motor 153, the engine 135 of the power generating unit is started. According to this embodiment, the member that is engaged when starting the engine 135 is exposed to the outside, so that the motor 153 for starting the engine can be easily connected. Furthermore, since the crankshaft (rotating shaft) 150 of the engine 135 is arranged in the vertical direction, it is easy to connect the motor 153 for starting the engine. That is, when starting the engine, it is necessary to press connector 148 of engine start-up motor 153 against spinner cone 151, but in this embodiment, connector 148 is pressed from top to bottom, so spinner cone 151 does not slip away.

[0038] It is recommended that the crankshaft (rotation axis) 150 be oriented vertically when the multicopter 100 is placed in a horizontal position, but if it is oriented generally vertically, the multicopter 100 will be less likely to move when started. The orientation of the crankshaft (rotation shaft) 150 is recommended to be 45 degrees or less with respect to the vertical direction, and preferably 30 degrees or less, and more preferably 5 degrees or less with respect to the vertical direction.

[0039] In the multicopter 100 of this embodiment, the outer cover member 127 has openings 142 and 143, which communicate with the inside and outside of the support frame portion 105. The lower part of the support frame portion 105 is open to the outside via a small cavity portion 138. Therefore, in the multicopter 100 of this embodiment, the top and bottom of the hollow portion 108 are connected to each other, and the power generation unit 110 is disposed in the connected portion. That is, in this embodiment, the cavity 108 formed by the large cavity 137 and the small cavity 138 functions as an air passage in the vertical direction. The power generation unit 110 is disposed in a position surrounded by the ventilation flow path, and is therefore disposed in an area that is vertically penetrated and has ventilation in the vertical direction. In the multicopter 100 of this embodiment, during flight, wind is drawn into the cavity 108 of the support frame portion 105, and the power generation unit 110 is exposed to a ventilated environment. That is, when the multicopter 100 moves forward, it is in a slightly forward-leaning position, which causes wind to be drawn into the cavity 108, exposing the power generation unit 110 to a ventilated environment, as shown in FIG. As a result, the power generation unit 110 is cooled.

[0040] In the multicopter 100 of this embodiment, the generator 11 is driven by the engine 135 during flight, and the motor 20 is driven by the electricity from the generator 11. In addition, surplus electricity is stored in a storage battery (not shown). In this embodiment, the generator 11 is connected to the storage battery, and if the amount of power generated by the generator 11 is insufficient, the shortage is made up for by the storage battery. This stabilizes the drive of the motor 20 and the operation of the control device (not shown). If the amount of power generation is excessive, the power is stored in the storage battery. Therefore, the multicopter 100 of this embodiment has a long cruising range.

[0041] In the embodiment described above, the entire generator 11 and part of the engine 135 are located in the area surrounded by the annular portion of the annular structure 111, and another part of the engine 135 is located in the area above the area surrounded by the annular portion of the annular structure 111, but the entire engine 135 may also be housed in the area surrounded by the annular portion of the annular structure 111. Furthermore, a part or all of the engine 135 or the generator 11 may be located in an area above or below the area surrounded by the annular portion of the annular structural portion 111 .

[0042] In the embodiment described above, spinner cone 151 is provided at the end of engine 135. Spinner cone 151 is a component of a model airplane, and in this embodiment, it is used as an engagement piece for engaging engine startup motor 153, away from its original purpose. The component for engaging engine startup motor 153 is not limited to spinner cone 151, and may be another engagement piece. Also, the engagement piece may not be present. In this embodiment, the spinner cone 151 serving as the engaging piece is always exposed to the outside, but it may be exposed by removing the lid or the like. The term "exposed" refers to a state in which a member can be connected from the outside, and the engaging piece may be provided in a recessed position.

[0043] All of the multicopters described above have a fuel tank or a component equivalent to a fuel tank. Therefore, when the remaining amount of fuel becomes low, an air layer forms in the fuel tank and the support frame that stores the fuel, reducing the overall specific gravity. If the multicopter mentioned above crashes into a pond or the ocean and has little fuel, it will float to the surface of the water, making it possible to recover the crashed multicopter.

[0044] The multicopter described above is equipped with a storage battery, but the storage battery may be omitted and power may be supplied directly from the generator to the motor 20 and the control device. In the embodiment described above, the planar shape of the support frame portion 105 is circular, but it may also be elliptical or polygonal.

[0045] All of the multicopters described above have a ring-shaped support frame, but the shape of the frame itself can be arbitrary, and it may be branched or radial. Although the multicopters described above all have ventilation in the vertical direction, ventilation is not essential.

[0046] In the embodiment described above, fuel is stored in the hollow portion 200 inside the support frame portion 105, but a separate fuel tank may also be provided. [Explanation of symbols]

[0047] 2 rotor blades 11. Generator 20 Motor 100 Multicopters 103 Main body 105 Support frame part 110 Power Generation Unit 111 Annular structure 135 Engine 137 Large Cavity 138 Small cavity 150 rotation axis 151 Spinner Cone 153 Motor 200 Hollow part

Claims

1. A multicopter having a generator driven by an engine and rotors that rotate by a motor to generate lift, The rotation axis of the engine is arranged to be generally oriented in the vertical direction, The generator is located on the lower side of the engine, a member that rotates integrally with the rotary shaft, the member being exposed at an upper portion of the engine; the member is an engagement piece to which a motor that starts the engine is connected, a main body portion, and a plurality of the rotor blades are attached to the main body portion; The main body has an annular support frame that is air permeable in the vertical direction. the engine and the generator are mounted in a space surrounded by the support frame portion, A multicopter characterized in that the space surrounded by the support frame portion does not have any rotors that generate lift separate from the rotors.

2. the main body further includes a plurality of ribs attached to the support frame; the plurality of rib portions extend outward from the support frame portion, The multicopter according to claim 1 , wherein the rotors are attached to the plurality of rib portions.

3. A multicopter having a generator driven by an engine and rotors that rotate by a motor to generate lift, The rotation axis of the engine is arranged to be generally oriented in the vertical direction, The generator is located on the lower side of the engine, a member that rotates integrally with the rotary shaft, the member being exposed at an upper portion of the engine; the member is an engagement piece to which a motor that starts the engine is connected, a main body portion, and a plurality of the rotor blades are attached to the main body portion; The main body has an annular support frame that is air permeable in the vertical direction. A multicopter characterized in that the space surrounded by the support frame portion does not have any rotors that generate lift separate from the rotors.

4. 4. A multicopter according to claim 1, wherein the support frame itself has a hollow portion therein, and fuel can be stored in the hollow portion.

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