Engine device of an unmanned aerial vehicle

Abstract

The present invention provides an engine device for an unmanned aerial vehicle. This device provides good weight balance for the aircraft; can eliminate the gyroscopic effect; and has a propeller that can rotate automatically. The engine device of the present invention includes: a first cylinder and a second cylinder, which are horizontally arranged and opposed to each other, and the pistons in the cylinders advance and retreat in opposite directions; a first crankshaft and a second crankshaft, which are arranged vertically, are respectively driven by the first cylinder and the second cylinder, and rotate in opposite directions; a first centrifugal clutch and a second centrifugal clutch, which rotate in opposite directions; a final drive shaft transmits the rotational force to a gear mechanism including a cross-orthogonal transformation gear to rotate the propeller shaft; and, a one-way clutch, which is arranged between (1) the first crankshaft, the second crankshaft, and (2) the final drive shaft, and is driven by both the first crankshaft and the second crankshaft.

Description

Technical Field

[0001] The present invention relates to an engine device for an unmanned aerial vehicle. More specifically, it relates to an engine device for an unmanned aerial vehicle, which has two centrifugal clutches corresponding to two crankshafts in a horizontally opposed engine of the unmanned aerial vehicle. Background Art

[0002] Reciprocating engines have been more frequently used in unmanned aerial vehicles (UAVs). In-line engines and horizontally opposed engines are representatives of reciprocating engines. The pistons and cylinder blocks of a horizontally opposed engine are respectively arranged on the left and right sides of the crankshaft. Compared with an in-line engine, the horizontally opposed engine has advantages such as small engine vibration and short length of the engine in the front-rear direction.

[0003] Patent Document 1 discloses an engine in which a first piston and a second piston are vertically erected; and a first crankshaft and a second crankshaft, corresponding to the first piston and the second piston respectively, are horizontally arranged below the first piston and the second piston. The first crankshaft and the second crankshaft rotate in opposite directions to each other to eliminate the gyroscopic effect of the aircraft.

[0004] For a reciprocating engine in an unmanned aerial vehicle having multiple propellers, the following points need to be noted:

[0005] (1) Improve the weight balance of the aircraft. Specifically, the output shaft of the engine is located at the center of the aircraft, and the center of gravity of the engine coincides with the center of gravity of the aircraft;

[0006] (2) The gyroscopic effect of the rotating components inside the engine does not have an adverse impact on the controllability of the aircraft;

[0007] (3) Even if the engine stops due to a failure, the aircraft can land safely, that is, even if the engine stops, the propellers can automatically rotate by receiving the airflow.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1

[0011] Japanese Unexamined Patent Application Publication No.: 2019 - 148186 Summary of the Invention

[0012] Technical Problem to be Solved

[0013] The object of the present invention is to provide an engine device for an unmanned aerial vehicle, which

[0014] (1) brings good weight balance to the aircraft;

[0015] (2) The gyroscopic effect that can have an adverse effect on the controllability of the flying device can be eliminated; and

[0016] (3) It has a propeller that can rotate automatically even when the engine stops.

[0017] The method of solving the technical problem

[0018] According to the present invention, an engine device for an unmanned aerial vehicle includes: a first cylinder and a second cylinder, which are horizontally arranged on the axis in the left - right direction and are opposed to each other, and the pistons in the cylinders advance and retreat in opposite directions; a first crankshaft and a second crankshaft, which are arranged in the vertical direction perpendicular to the axis, are respectively driven by the first cylinder and the second cylinder, and rotate in opposite directions; a first centrifugal clutch and a second centrifugal clutch, which are arranged above the first crankshaft and the second crankshaft, and rotate in opposite directions; a final drive shaft, which transmits the rotational force to a gear mechanism to rotate the propeller shaft; and, a one - way clutch, which is arranged between

[0019] (1) the first crankshaft and the second crankshaft; and

[0020] (2) the final drive shaft, and is driven by both the first crankshaft and the second crankshaft.

[0021] In this engine device, the exhaust pipe from the first cylinder and the exhaust pipe from the second cylinder are connected at an equal - length point, then turned into a U - shape and connected to a muffler arranged below the exhaust pipe.

[0022] In the engine device, a first camshaft and a second camshaft are respectively provided in the first cylinder and the second cylinder to control their respective valves, one of the camshafts is driven by the first crankshaft, and the other camshaft is driven by the second crankshaft through a reversing gear; and the first camshaft and the second camshaft rotate in the same direction.

[0023] The effects of the present invention

[0024] The engine device for an unmanned aerial vehicle according to the present invention:

[0025] (1) A first centrifugal clutch and a second centrifugal clutch are provided. Since the first centrifugal clutch and the second centrifugal clutch rotate in opposite directions with a large momentum, the gyroscopic effect can be eliminated, and the attitude control of the flying device becomes easy;

[0026] (2) Providing two centrifugal clutches can make the height of the engine device lower than providing one centrifugal clutch with a large radius and height. Moreover, the first centrifugal clutch and the second centrifugal clutch can be arranged at symmetric positions near the center of the engine, and the center of gravity can be maintained at the center;

[0027] (3) Since a one-way clutch is provided, automatic rotation can be performed, which can greatly reduce the risk of collision. For example, the propeller side of the shaft of the one-way clutch can keep rotating;

[0028] (4) Because

[0029] (a) The first cylinder and the second cylinder are horizontally arranged on the axis in the left-right direction and are opposed to each other; and

[0030] (b) The pistons in the cylinders move forward and backward in opposite directions, and the vibration of the pistons is eliminated, which makes the engine device have low vibration.

[0031] (5) Since the first crankshaft and the second crankshaft are vertically arranged, the length of the engine in the front-rear direction can be reduced.

[0032] Further, in the engine device according to the present invention, the exhaust pipe from the first cylinder and the exhaust pipe from the second cylinder are connected at a point of equal length, then turned into a U shape, and connected to a muffler provided below the engine device:

[0033] (1) Since the muffler is arranged at the bottom of the engine, the center of gravity of the engine can be kept near its center;

[0034] (2) Since there is only one muffler, the engine device can be lightweight and compact.

[0035] (3) Since the exhaust pipes are connected at a point of equal length and combined into one, the volume of the exhaust pipes can be saved.

[0036] Further, in the engine device according to the present invention, a first camshaft and a second camshaft are respectively provided in the first cylinder and the second cylinder to control their respective valves, and one of the camshafts is driven by the first crankshaft, and the other camshaft is driven by the second crankshaft through a reversing gear; and the first camshaft and the second camshaft rotate in the same direction:

[0037] Since the first camshaft and the second camshaft rotate in the same direction, the control units of the first cylinder, the second cylinder, the pistons and the valves can be shared. Although the camshafts rotate in the same direction, the resulting gyroscopic effect is very small and can be ignored. The beneficial effect of sharing components is greater than the very small gyroscopic effect. Description of the Drawings

[0038] Figure 1 is a perspective view of an engine device for an unmanned aerial vehicle according to the present invention.

[0039] Figure 2is a perspective view of an engine device for an unmanned aerial vehicle according to the present invention.

[0040] Figure 3 Shows the rotation directions of the main components of the engine device for an unmanned aerial vehicle.

[0041] Figure 4 is an external view of the engine device for an unmanned aerial vehicle including accessories.

[0042] Figure 5 is Figure 4 a left view of the engine device. DETAILED DESCRIPTION

[0043] The following provides a detailed description of the engine device for an unmanned aerial vehicle according to the present invention.

[0044] Embodiment

[0045] Figure 1 is a perspective view of an engine device for an unmanned aerial vehicle according to the present invention. This perspective view is seen obliquely downward from the upper right rear. This view is shown with the outer shell removed so that the interior can be seen. The engine device 100 is a twin-cylinder engine, and the first cylinder and the second cylinder are horizontally arranged on the axis in the left-right direction and are opposed to each other. A first piston 11 is installed in the first cylinder, and a second piston 21 is installed in the second cylinder. As an example, a second camshaft is provided and is rotated by a second gear 27 driven by a second belt 28 to control the exhaust valve and the intake valve.

[0046] As Figure 1 shown, the first crankshaft 30 and the second crankshaft 40 are vertically arranged in the vertical direction perpendicular to the axis. The first crankshaft 30 is driven and rotated by the first piston 11 of the first cylinder 10. The second crankshaft 40 is driven and rotated by the second piston 21 of the second cylinder 20. The first crankshaft 30 and the second crankshaft 40 rotate in opposite directions to eliminate the gyroscopic effect. A first generator 64 is provided below the first crankshaft 30, and a second generator 65 is provided below the second crankshaft 40. The first generator 64 and the second generator 65 generate electricity by the rotation of the first crankshaft 30 and the second crankshaft 40 and supply power to the ignition system of the engine, the fuel supply system, and the control unit of the unmanned aerial vehicle, etc. A starter 75 is provided at the lower rear of the engine.

[0047] The first centrifugal clutch 80 and the second centrifugal clutch 90 are respectively arranged above the first crankshaft 30 and the second crankshaft 40. The rotational force of the first crankshaft 30 is transmitted to the first centrifugal clutch 80. The rotational force of the second crankshaft 40 is transmitted to the second centrifugal clutch 90. When the rotational speed of the first crankshaft 30 increases, centrifugal force acts on the internal weights, and the clutch disc of the first centrifugal clutch 80 is engaged, and the first centrifugal clutch 80 rotates its output gear that protrudes downward in Figure 2 Similarly, when the rotational speed of the second crankshaft 40 increases, the second centrifugal clutch 90 rotates its output gear that protrudes downward in Figure 2 .

[0048] A one-way clutch 50 is arranged below the first centrifugal clutch 80 and the second centrifugal clutch 90. The outer gear of the one-way clutch 50 is driven by both the first centrifugal clutch 80 and the second centrifugal clutch 90. The first centrifugal clutch 80 and the second centrifugal clutch 90 rotate in opposite directions to each other. In this embodiment, the rotational direction of the output gear of the first centrifugal clutch 80 is reversed by the reversing gear 34, and the output gear drives the one-way clutch 50 through the reversing gear. The output gear of the second centrifugal clutch 90 directly drives the one-way clutch 50. The output shaft of the one-way clutch 50 rotates in one direction by transmitting the rotational force of the first centrifugal clutch 80, and the second centrifugal clutch 90 transmits to the output shaft of the one-way clutch 50 through the internal hook, and the output shaft rotates in one direction. Even without the drive of the hook, the output shaft can rotate in one direction, playing the role of a so-called one-way clutch.

[0049] The output shaft of the one-way clutch 50 transmits its rotational force to the final drive shaft 60 through a gear. A gear mechanism 70 including a cross transformation gear is provided in the final drive shaft 60, and the rotational force is transmitted to the propeller shafts 71 to 74 in four directions.

[0050] Figure 2 is a perspective view of the engine device 100 for an unmanned aerial vehicle according to the present invention. This perspective view is seen obliquely upward from the lower right rear. Explanation will be made as a supplement to Figure 1 . The first cylinder 10 and the second cylinder 20 are horizontally arranged and opposed to each other. The first crankshaft 30 and the second crankshaft 40 are arranged in the vertical direction perpendicular to the line connecting the first cylinder 10 and the second cylinder 20.

[0051] As Figure 2As shown, the first camshaft 16 is rotated by a first gear 17 driven by a first belt 18. The first camshaft 16 controls the exhaust valve and the intake valve of the first cylinder 10. The first piston 11 is within the first cylinder, connected to its connecting rod, and rotates the first crankshaft 30. The second piston 21 is within the second cylinder, connected to its connecting rod, and rotates the second crankshaft 40. The second belt 28 of the second cylinder 20 is driven by a gear disposed within the shaft of the reversing gear 29 to reverse the direction of rotation of the second crankshaft 40. That is, the direction of rotation of the second camshaft 26 is opposite to the direction of rotation of the second crankshaft 40.

[0052] The portion below the first centrifugal clutch 80 is configured as follows. The driven gear 31 is driven by the gear of the first crankshaft 30 and rotates the first centrifugal clutch shaft 32. When the rotational speed of the first centrifugal clutch shaft 32 increases, centrifugal force acts on the weights within the first centrifugal clutch 80, and the clutch plates provided within the first centrifugal clutch 80 are engaged. Thereby, the first centrifugal clutch output gear 33 below the first centrifugal clutch 80 rotates. The direction of rotation of the first centrifugal clutch output gear 33 is reversed by the reversing gear 34. The reversing gear 34 meshes with the one-way clutch gear 51 of the one-way clutch 50 and rotates the one-way clutch 50. Accordingly, the one-way clutch shaft 52 rotates, and the rotational force is transmitted to the final drive shaft 60 through the driven gear 63 via the drive gear 53 provided within the one-way clutch shaft 52. The second centrifugal clutch 90 has a similar structure, and the output of the second centrifugal clutch 90 is shown by the second centrifugal clutch output gear 43. However, there is no reversing gear, and the second centrifugal clutch output gear 43 meshes with the one-way clutch gear 51, and the rotational force is transmitted.

[0053] Figure 3 The direction of rotation of the main components of the engine device of the unmanned aerial vehicle is shown. This perspective view is obliquely downward from the upper right front. The direction of rotation is defined as the first crankshaft 30 rotating clockwise and the second crankshaft 40 rotating counterclockwise. From the arrangement of the gears, the first centrifugal clutch 80 rotates counterclockwise and the second centrifugal clutch 90 rotates clockwise. In either case, the directions of rotation are opposite to each other, and the gyroscopic effect can be canceled thereby. Although the first camshaft 16 and the second camshaft 26 rotate in the same clockwise direction, the resulting gyroscopic effect is very small and can be ignored. The beneficial effects of the common components are greater than the very small gyroscopic effect.

[0054] Refer to Figure 3, the configuration under the first centrifugal clutch 80 is explained as follows. The driven gear 31 of the first centrifugal clutch 80 is driven by the drive gear 37 of the first crankshaft 30, and the first centrifugal clutch shaft 32 is rotated. When the first centrifugal clutch shaft 32 rotates, centrifugal force acts on the internal weights of the first centrifugal clutch 80, and the internal clutch plates are engaged. Thereby, the first centrifugal clutch output gear 33 under the first centrifugal clutch 80 rotates (see Figure 2 ). Similarly, the driven gear 41 of the second centrifugal clutch 90 is driven by the drive gear 47 of the second crankshaft 40, and the second centrifugal clutch shaft 42 is rotated. When the second centrifugal clutch shaft 42 rotates, centrifugal force acts on the internal weights of the second centrifugal clutch 90, and the internal clutch plates are engaged. Thereby, the second centrifugal clutch output gear 43 under the second centrifugal clutch 90 rotates (see Figure 2 ).

[0055] As Figure 3 shown, two gears 36 with the same number of teeth are arranged between the first crankshaft 30 and the second crankshaft 40 and rotate meshing with each other. Since one gear 36 is driven by the first crankshaft 30 and the other gear 36 is driven by the second crankshaft 40, the rotational speeds of the first crankshaft 30 and the second crankshaft 40 are the same.

[0056] Figure 4 is an external view of the engine device of the unmanned aerial vehicle including the accessories, Figure 5 is Figure 4 a left view of the engine device. As Figure 4 shown, the first radiator or oil cooler 67 and the second radiator or oil cooler 68 are respectively used for cooling the first cylinder 10 and the second cylinder 20. The exhaust pipe 55 includes a first exhaust pipe 56 and a second exhaust pipe 57, which are connected at the connection part, then turned into a U shape and connected to the muffler 59. The lengths of the first exhaust pipe 56 and the second exhaust pipe 57 to the connection part are the same. As Figure 5 shown, the muffler 59 is arranged at the center of the bottom of the engine. Therefore, the center of gravity of the aircraft can be maintained without deviation in the front-rear direction.

[0057] Industrial Applicability

[0058] According to the present invention, the first centrifugal clutch and the second centrifugal clutch respectively provided corresponding to the first camshaft and the second camshaft rotate in opposite directions to each other, so the gyro effect can be eliminated and the attitude control of the aircraft becomes easy. The engine device of the present invention is applicable to unmanned aerial vehicles.

[0059] Explanation of Reference Numerals

[0060] 10. First cylinder

[0061] 11. First piston

[0062] 16. First camshaft

[0063] 17. First gear

[0064] 18. First belt

[0065] 20. Second cylinder

[0066] 21. Second piston

[0067] 26. Second camshaft

[0068] 27. Second gear

[0069] 28. Second belt

[0070] 29. Reverse gear

[0071] 30. First crankshaft

[0072] 31. Driven gear

[0073] 32. First centrifugal clutch shaft

[0074] 33. First centrifugal clutch output gear

[0075] 34. Reverse gear

[0076] 35. Shaft

[0077] 36. Gear

[0078] 37. Driving gear

[0079] 40. Second crankshaft

[0080] 41. Driven gear

[0081] 42. Second centrifugal clutch shaft

[0082] 43. Second centrifugal clutch output gear

[0083] 47. Driving gear

[0084] 50. One-way clutch

[0085] 51. One-way clutch gear

[0086] 52. One-way clutch output shaft

[0087] 53. Driving gear

[0088] 55. Exhaust pipe

[0089] 56. First exhaust pipe

[0090] 57. Second exhaust pipe

[0091] 58. Connecting part

[0092] 59. Muffler

[0093] 60. Final drive shaft

[0094] 63. Driven gear

[0095] 64. First generator

[0096] 65. Second generator

[0097] 67. First radiator or oil cooler

[0098] 68. Second radiator or oil cooler

[0099] 70. Gear mechanism

[0100] 71, 72, 73, 74. Propeller shaft

[0101] 75. Starter

[0102] 80. First centrifugal clutch

[0103] 90. Second centrifugal clutch

[0104] 100. Engine device for unmanned aerial vehicle.

Claims

1. An engine device for an unmanned aerial vehicle, characterized in that, Comprising a first cylinder and a first piston, and a second cylinder and a second piston, configured to be horizontally arranged and opposed to each other on the axis in the left-right direction of the aircraft, and the first piston in the first cylinder and the second piston in the second cylinder advance and retreat in opposite directions; a first crankshaft and a second crankshaft, which are arranged in the vertical direction of the aircraft perpendicular to the axis, and are respectively driven by the first piston in the first cylinder and the second piston in the second cylinder, and rotate in opposite directions; a first centrifugal clutch and a second centrifugal clutch, which are arranged above the first crankshaft and the second crankshaft, and rotate in opposite directions, wherein the rotational force of the first crankshaft is transmitted to the first centrifugal clutch, and the rotational force of the second crankshaft is transmitted to the second centrifugal clutch; a one-way clutch, which is driven by both the first centrifugal clutch and the second centrifugal clutch to rotate in the same direction; and a final drive shaft, which transmits the rotational force to a gear mechanism including a bevel gear to rotate the propeller shaft in four directions, and the rotational force of the output shaft of the one-way clutch is transmitted to the final drive shaft.

2. The engine device according to claim 1, characterized in that: The exhaust pipe from the first cylinder and the exhaust pipe from the second cylinder are connected at a place of equal length, then turned into a U shape, and connected to a muffler provided below the engine device.

3. The engine device according to claim 1, characterized in that: A first camshaft and a second camshaft are respectively provided in the first cylinder and the second cylinder to control their respective valves, and one of the camshafts is driven by the first crankshaft, and the other camshaft is driven by the second crankshaft through a reversing gear; and the first camshaft and the second camshaft rotate in the same direction.

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