Abstract: There is provided a variable valve apparatus including: a plurality of rocker arms; a coupling pin disposed in a housing hole of the rocker arm closer to one side; a release pin disposed in a housing hole of the rocker arm closer to the other side; a pressing member; a transmission member; and a push-back member disposed so as to push back the transmission member from the other side. The pressing member is configured to push the coupling pin into the housing hole of the rocker arm closer to the other side to couple the plurality of rocker arms. The transmission member is configured to push back the coupling pin into the housing hole of the rocker arm closer to the one side to release a coupling of the plurality of rocker arms.

Abstract: A variable valve device includes a pair of cam housings separated in a predetermined direction, a rocker shaft supported by the pair of cam housings, rocker arms supported by the rocker shaft, a connecting pin disposed in a pin hole of one of the rocker arms, a return pin disposed in a pin hole of another of the rocker arms, a pressing member that causes the connecting pin to push the return pin to the other side, a repulsive member that causes the return pin to push back the connecting pin to one side, and an upper housing supported at both ends by upper surfaces of the pair of cam housings. In the variable valve device, the upper housing is formed with a first accommodation hole in which the pressing member is disposed and a second accommodation hole in which the repulsive member is disposed.

Abstract: A variable valve device can change valve operations of a cylinder head in which a cam chain is disposed at a center in a predetermined direction where cylinders are arranged and spark plugs are arranged by recessing outer walls on both sides in the direction in a concave shape. The device includes, for each cylinder, a rocker shaft extending along the direction, rocker arms supported by the rocker shaft, a connecting pin disposed in a pin hole of one of the rocker arms, a return pin disposed in a pin hole of the other of the rocker arms, a pressing member that causes the connecting pin to push the return pin, and a repulsive member that causes the return pin to push back the connecting pin, and the pins and the members are separated from the plug in a direction orthogonal to the direction in a plan view.

Abstract: There is provided an installation structure for an oil control valve configured to control a hydraulic pressure to a variable valve device, in an engine in which a cylinder head cover is provided on a cylinder head, and the variable valve device that is configured to change an opening and closing timing of a valve by a hydraulic pressure is mounted. The installation structure includes: a first slope that slopes upward and rearward from a front end on an upper surface of the cylinder head cover; and a second slope that slopes downward and rearward from a rear end of the first slope on the upper surface of the cylinder head cover. A radiator is installed in front of the cylinder head cover, and the oil control valve is installed on the second slope.

Abstract: There is provided a variable valve device provided in a cylinder head and capable of changing a valve lift amount, including: a camshaft on which a plurality of cams with different valve lift amounts are formed; a switching mechanism configured to switch a cam for moving a valve among the plurality of cams; and an oil control valve configured to control an oil pressure for the switching mechanism. Oil starts to be supplied from the oil control valve to the switching mechanism at an end timing of a valve lift or in a zero range in which no valve lift occurs.

Abstract: There is provided a lubricating structure for a power transmission mechanism in which a crankshaft is coupled to a piston disposed in a cylinder bore and in which power is transmitted from the crankshaft to a camshaft. The lubricating structure includes: an idler gear that is configured to transmit power from the crankshaft to the camshaft; and an idler gear shaft that supports the idler gear via a bearing. One end portion of the idler gear shaft protrudes into the cylinder bore, and an oil passage configured to guide oil from the cylinder bore to the bearing is formed in the idler gear shaft.

Abstract: There is provided a variable valve apparatus including: a plurality of rocker arms; a coupling pin disposed in a housing hole of the rocker arm closer to one side; a release pin disposed in a housing hole of the rocker arm closer to the other side; a pressing member; a transmission member; and a push-back member disposed so as to push back the transmission member from the other side. The pressing member is configured to push the coupling pin into the housing hole of the rocker arm closer to the other side to couple the plurality of rocker arms. The transmission member is configured to push back the coupling pin into the housing hole of the rocker arm closer to the one side to release a coupling of the plurality of rocker arms.

Abstract: There is provided a lubricating structure for a power transmission mechanism in which a crankshaft is coupled to a piston disposed in a cylinder bore and in which power is transmitted from the crankshaft to a camshaft. The lubricating structure includes: an idler gear that is configured to transmit power from the crankshaft to the camshaft; and an idler gear shaft that supports the idler gear via a bearing. One end portion of the idler gear shaft protrudes into the cylinder bore, and an oil passage configured to guide oil from the cylinder bore to the bearing is formed in the idler gear shaft.

Abstract: There is provided a mounting structure of an oil control valve unit configured to control a hydraulic pressure to a variable valve timing device of an engine. The engine is supported by a vehicle body frame. A heat exchanger is mounted in front of the engine. The oil control valve unit is mounted at a side of the engine. A part of the vehicle body frame is arranged between the oil control valve unit and the heat exchanger in a front and rear direction.

Abstract: There is provided an assembling structure of an engine. An oil control valve unit is configured to control oil pressure in a variable valve timing device of the engine. The oil control valve unit is installed on a cylinder head. The cylinder head is assembled to a crankcase. An outer wall of the cylinder head is formed with an opening into which the oil control valve unit is partially inserted. A mating surface of the cylinder head and the crankcase is fastened by at least a pair of bolts spaced apart across the opening.

Abstract: There is provided a mounting structure of an oil control valve unit configured to control a hydraulic pressure to a variable valve timing device of an engine. The engine is provided with a transmission. A heat exchanger is mounted in front of the engine. The oil control valve unit is mounted at a side of the engine. A transmission cover configured to cover the transmission from a side bulges from a side surface of the engine and the oil control valve unit is mounted above the transmission cover.

Abstract: There is provided an assembling structure of an engine. An oil control valve unit is configured to control oil pressure in a variable valve timing device of the engine. The oil control valve unit is installed on a cylinder head. The cylinder head is assembled to a crankcase. An outer wall of the cylinder head is formed with an opening into which the oil control valve unit is partially inserted. A mating surface of the cylinder head and the crankcase is fastened by at least a pair of bolts spaced apart across the opening.

Abstract: There is provided an installation structure of an oil control valve unit configured to control a hydraulic pressure in a variable valve timing device of an engine by a control valve supported by a valve housing. The engine is formed with an installation surface on which the valve housing is installed. The valve housing is installed on the installation surface by a plurality of bolts. Two bolts of the plurality of bolts are attached at facing positions across a center of the valve housing in a direction along a cylinder axial direction of the engine.

Abstract: There is provided a mounting structure of an oil control valve unit configured to control a hydraulic pressure to a variable valve timing device of an engine. The engine is supported by a vehicle body frame. The oil control valve unit is mounted to an outer surface of the engine. The oil control valve unit is detachably mounted to the outer surface of the engine avoiding the vehicle body frame.

Abstract: To provide an internal combustion engine that can inject lubricating oil to both of the first region in the skirt of the piston and the second region outside the skirt with fewer nozzles. An internal combustion engine including: a piston configured to reciprocate in a cylinder bore; and an oil injector configured to inject lubricating oil to the piston. The piston includes pin bosses, skirts, side walls, and a piston inner region that is surrounded by respective inner surfaces of the pin bosses, skirts, and side walls. The oil injector is configured to inject the lubricating oil to the pair of pin bosses when the piston is at one of a top dead center and a bottom dead center, and inject the lubricating oil to the piston inner region when the piston is at another of the top dead center and the bottom dead center.

Abstract: There is provided a mounting structure of an oil control valve unit configured to control a hydraulic pressure to a variable valve timing device of an engine. The engine is supported by a vehicle body frame. A heat exchanger is mounted in front of the engine. The oil control valve unit is mounted at a side of the engine. A part of the vehicle body frame is arranged between the oil control valve unit and the heat exchanger in a front and rear direction.

Abstract: There is provided an oil control valve unit configured to control a hydraulic pressure to intake-side and exhaust-side variable valve timing devices of an engine. An intake control valve is configured to control an intake-side valve timing. An exhaust control valve is configured to control an exhaust-side valve timing. A valve housing is configured to support the intake control valve and the exhaust control valve. The engine is formed therein with a main gallery to which oil is to be delivered from an oil pump. The valve housing is connected with an external piping extending from the main gallery and the oil is supplied from the main gallery to an oil passage in the valve housing through the external piping.

Abstract: There is provided a mounting structure of an oil control valve unit configured to control a hydraulic pressure to a variable valve timing device of an engine. The engine is supported by a vehicle body frame. The oil control valve unit is mounted to an outer surface of the engine. The oil control valve unit is detachably mounted to the outer surface of the engine avoiding the vehicle body frame.

Abstract: There is provided a mounting structure of an oil control valve unit configured to control a hydraulic pressure to a variable valve timing device of an engine. The engine is provided with a transmission. A heat exchanger is mounted in front of the engine. The oil control valve unit is mounted at a side of the engine. A transmission cover configured to cover the transmission from a side bulges from a side surface of the engine and the oil control valve unit is mounted above the transmission cover.

Abstract: An engine unit of a motorcycle includes a crankshaft, a piston, and a swing member. The crankshaft is housed in a crankcase in a direction such that a rotational center line is parallel to a vehicle-width direction. The piston is disposed above the crankshaft and reciprocates in an approximately up-down direction. The swing member is disposed forward of the crankshaft and the piston, coupled to the crankshaft by a coupling member, and swings in an approximately front-rear direction synchronized with a rotation of the crankshaft.