Abstract: An engine device for an unmanned flying apparatus that provides good weight balance for the flying apparatus; cancels the gyroscopic effect; and has auto rotating propellers. The engine device includes a first cylinder and a second cylinder arranged horizontally and opposed to each other, and pistons within the cylinders advance and retract in opposite directions to each other; a first crankshaft and a second crankshaft arranged in the vertical direction, driven by the first cylinder and the second cylinder, respectively, and rotate in opposite directions; a first centrifugal clutch and a second centrifugal clutch rotate in opposite directions to each other; a final drive shaft transmitting rotational force to a gear mechanism comprising orthogonal transform gears, to rotate a propeller shaft; a one-way clutch arranged between the first crankshaft, the second crankshaft and the final drive shaft, and driven by both the first crankshaft and the second crankshaft.

Abstract: An engine device for an unmanned flying apparatus that provides good weight balance for the flying apparatus; cancels the gyroscopic effect; and has auto rotating propellers. The engine device includes a first cylinder and a second cylinder arranged horizontally and opposed to each other, and pistons within the cylinders advance and retract in opposite directions to each other; a first crankshaft and a second crankshaft arranged in the vertical direction, driven by the first cylinder and the second cylinder, respectively, and rotate in opposite directions; a first centrifugal clutch and a second centrifugal clutch rotate in opposite directions to each other; a final drive shaft transmitting rotational force to a gear mechanism comprising orthogonal transform gears, to rotate a propeller shaft; a one-way clutch arranged between the first crankshaft, the second crankshaft and the final drive shaft, and driven by both the first crankshaft and the second crankshaft.

Abstract: There is provided a lubrication structure of an internal combustion engine. A transmission chamber is arranged adjacently at the rear of a crank chamber. An oil chamber communicates with a bottom part of the transmission chamber. A feed pump supplies oil in the oil chamber to a lubrication target part. A scavenging pump sucks the oil in the crank chamber and discharges the oil to the transmission chamber. The feed pump and the scavenging pump are arranged coaxially in a width direction of the internal combustion engine. At least a part of the scavenging pump is arranged higher than a lower end of the crank chamber. A rear end of the scavenging pump is arranged at the same position as a rear end of the crank chamber or in front of the rear end of the crank chamber in a front and rear direction.

Abstract: The present invention is capable of more smoothly changing a phase of a cam shaft in a rotation direction. A variable valve mechanism changes an opening/closing timing of an intake valve or an exhaust valve in response to an engine rotation speed. The variable valve mechanism includes: a cam sprocket which rotates in response to a rotation of a crank shaft; an intake cam shaft which is integrated with an intake cam and is provided to be rotatable relatively to the cam sprocket; and a link member that transmits a rotation from the cam sprocket to the intake cam shaft. The link member is supported by the cam sprocket to be swingable and swings in response to a change in rotation speed of the cam sprocket to rotate the intake cam shaft relatively to the cam sprocket.

Abstract: An overhead valve actuation mechanism for an engine includes a camshaft that is rotatably supported by the cylinder head and includes one or a plurality of valve cams. The camshaft operates opening and closing of an intake valve and an exhaust valve via the valve cam. The only one camshaft is disposed within the one cylinder head. The camshaft has an axis center biased to a side of the exhaust valve with respect to a cylinder axis line as viewed from an axial direction of the camshaft.

Abstract: The present invention can achieve a variable valve mechanism having a simple and compact configuration. A variable valve mechanism changes an opening/closing timing of an intake valve or an exhaust valve in response to an engine rotation speed. The variable valve mechanism includes: a cam sprocket which rotates in response to a rotation of a crank shaft; an intake cam shaft which is integrated with an intake cam; an exhaust cam shaft which is integrated with an exhaust cam; and a governor flange that transmits a rotation of the cam sprocket to the intake cam shaft and the exhaust cam shaft. The intake cam shaft and the exhaust cam shaft are formed so that the other cam shaft is inserted through one cam shaft to be relatively rotatable. The governor flange is provided to rotate along with the intake cam shaft and rotates relative to the cam sprocket under a predetermined condition.

Abstract: An overhead valve actuation mechanism for an engine includes a cylinder head, a camshaft that is rotatably supported by the cylinder head, includes one or a plurality of valve cams, and operates opening and closing of an air intake side or air exhaust side valve via the valve cam, a rocker arm that is swung by the valve cam of the camshaft and acts on the valve to open and close the valve, and a rocker arm shaft that is supported by the cylinder head and swingably supports the rocker arm. The rocker arm shaft includes a supporting portion supporting the rocker arm and a fixed shaft portion supported by the cylinder head. The supporting portion is formed such that a rotation axis of the rocker arm parallelly and slightly separates with respect to a center axis line of the fixed shaft portion.

Abstract: There is provided a lubrication structure of an internal combustion engine. A transmission chamber is arranged adjacently at the rear of a crank chamber. An oil chamber communicates with a bottom part of the transmission chamber. A feed pump supplies oil in the oil chamber to a lubrication target part. A scavenging pump sucks the oil in the crank chamber and discharges the oil to the transmission chamber. The feed pump and the scavenging pump are arranged coaxially in a width direction of the internal combustion engine. At least a part of the scavenging pump is arranged higher than a lower end of the crank chamber. A rear end of the scavenging pump is arranged at the same position as a rear end of the crank chamber or in front of the rear end of the crank chamber in a front and rear direction.

Abstract: A rocker arm includes a pivot portion that is journaled by a rocker arm shaft, a contact portion that projects from the pivot portion to a side of a valve cam, and a pressing portion that projects from the pivot portion to a side of a valve. While including a slipper projecting from the pivot portion in outer side in an axial direction to a side of a camshaft, an overhead valve actuation mechanism for the engine includes a stopper portion with which the slipper comes in contact when the rocker arm swings and reaches a predetermined position at a position opposing the slipper.

Abstract: An overhead valve actuation mechanism for an engine includes a camshaft that is rotatably supported by the cylinder head and includes one or a plurality of valve cams. The camshaft operates opening and closing of an intake valve and an exhaust valve via the valve cam. The only one camshaft is disposed within the one cylinder head. The camshaft has an axis center biased to a side of the exhaust valve with respect to a cylinder axis line as viewed from an axial direction of the camshaft.

Abstract: An overhead valve actuation mechanism for an engine includes a cylinder head, a camshaft that is rotatably supported by the cylinder head, includes one or a plurality of valve cams, and operates opening and closing of an air intake side or air exhaust side valve via the valve cam, a rocker arm that is swung by the valve cam of the camshaft and acts on the valve to open and close the valve, and a rocker arm shaft that is supported by the cylinder head and swingably supports the rocker arm. The rocker arm shaft includes a supporting portion supporting the rocker arm and a fixed shaft portion supported by the cylinder head. The supporting portion is formed such that a rotation axis of the rocker arm parallelly and slightly separates with respect to a center axis line of the fixed shaft portion.

Abstract: A rocker arm includes a pivot portion that is journaled by a rocker arm shaft, a contact portion that projects from the pivot portion to a side of a valve cam, and a pressing portion that projects from the pivot portion to a side of a valve. While including a slipper projecting from the pivot portion in outer side in an axial direction to a side of a camshaft, an overhead valve actuation mechanism for the engine includes a stopper portion with which the slipper comes in contact when the rocker arm swings and reaches a predetermined position at a position opposing the slipper.

Abstract: The present invention is capable of more smoothly changing a phase of a cam shaft in a rotation direction. A variable valve mechanism changes an opening/closing timing of an intake valve or an exhaust valve in response to an engine rotation speed. The variable valve mechanism includes: a cam sprocket which rotates in response to a rotation of a crank shaft; an intake cam shaft which is integrated with an intake cam and is provided to be rotatable relatively to the cam sprocket; and a link member that transmits a rotation from the cam sprocket to the intake cam shaft. The link member is supported by the cam sprocket to be swingable and swings in response to a change in rotation speed of the cam sprocket to rotate the intake cam shaft relatively to the cam sprocket.

Abstract: The present invention can achieve a variable valve mechanism having a simple and compact configuration. A variable valve mechanism changes an opening/closing timing of an intake valve or an exhaust valve in response to an engine rotation speed. The variable valve mechanism includes: a cam sprocket which rotates in response to a rotation of a crank shaft; an intake cam shaft which is integrated with an intake cam; an exhaust cam shaft which is integrated with an exhaust cam; and a governor flange that transmits a rotation of the cam sprocket to the intake cam shaft and the exhaust cam shaft. The intake cam shaft and the exhaust cam shaft are formed so that the other cam shaft is inserted through one cam shaft to be relatively rotatable. The governor flange is provided to rotate along with the intake cam shaft and rotates relative to the cam sprocket under a predetermined condition.

Abstract: A valve train mechanism of an internal combustion engine including a cylinder head formed with an intake port and an exhaust port, and a camshaft including a valve for opening or closing the intake port and the exhaust port formed in the cylinder head of the engine, a cam mounted to the camshaft so as to be rotated together, and a rocker arm supported on a rocker shaft to be swingable, in which the valve is opened or closed by swinging the rocker arm by rotation of the cam. The rocker shaft is formed with an oil passage, inside the rocker shaft, extending in an axial direction and with an oil outlet communicating with the oil passage and extending in a radial direction of the rocker shaft.

Abstract: A valve train mechanism of an internal combustion engine including a cylinder head formed with an intake port and an exhaust port, and a camshaft including a valve for opening or closing the intake port and the exhaust port formed in the cylinder head of the engine, a cam mounted to the camshaft so as to be rotated together, and a rocker arm supported on a rocker shaft to be swingable, in which the valve is opened or closed by swinging the rocker arm by rotation of the cam. The rocker shaft is formed with an oil passage, inside the rocker shaft, extending in an axial direction and with an oil outlet communicating with the oil passage and extending in a radial direction of the rocker shaft.