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US 2001/0017119 A1Published application
Valve cam mechanism for four-cycle engine
AssigneeSanshin Kogyo Kabushiki Kaisha
InventorsHiroyuki Suzuki, Katsumi Ochiai
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AssigneeSanshin Kogyo Kabushiki Kaisha
InventorsHiroyuki Suzuki, Katsumi Ochiai
Estimating the term…
A valve cam mechanism for a four-cycle engine includes an improved construction. The engine includes at least one camshaft having cam lobes to activate at least one of an intake valve and an exhaust valve. The camshaft defines an aperture next to at least one of the cam lobes. The aperture extends generally normal to an axis of the camshaft. A decompression mechanism is provided for manual starting of the engine. The decompression mechanism includes a shaft extending through the aperture. An actuator is affixed to the shaft for pivotal movement about an axis of the shaft. The actuator has a first section arranged to hold the intake or exhaust valve in an open position when the actuator exists in an initial position. A second section is arranged to initially retain the actuator in the initial position and to release the actuator from the initial position when the camshaft rotates. The shaft is rigidly supported by an inner surface of the aperture in part. A space is defined between the shaft and the inner surface of the aperture in the rest part.
An internal combustion engine comprising a cylinder block defining at least one cylinder bore, a piston reciprocating in the cylinder bore, a cylinder head member closing one end of the cylinder bore and defining a combustion chamber with the cylinder bore and the piston, an intake passage having an intake port through which air is introduced into the combustion chamber, an intake valve arranged to open and close the intake port, an exhaust passage having an exhaust port through which exhaust products are discharged from the combustion chamber, an exhaust valve arranged to open and close the exhaust port, at least one camshaft arranged for rotation and having cam lobes to activate at least one of the intake valve and the exhaust valve, the camshaft comprising an aperture extending therethrough and being positioned next to at least one of the cam lobes, the aperture extending generally normal to an axis of the camshaft, and a decompression mechanism configured to decompress the combustion chamber for starting of the engine, the decompression mechanism including a shaft extending through the aperture, an actuator affixed to the shaft for pivotal movement about an axis of the shaft, the actuator having a first section arranged to hold at least one of the intake valve and the exhaust valve in an open position when the actuator exists in an initial position, and a second section arranged to initially retain the actuator in the initial position and to release the actuator from the initial position when the camshaft rotates, the shaft being rigidly supported by an inner surface of the aperture and a space being defined between the shaft and at least a portion of the inner surface of the aperture.
An internal combustion engine comprising a combustion chamber, a valve arranged to open and close the combustion chamber to the atmosphere, a camshaft arranged for rotation and having a cam lobe to activate the valve, the camshaft defining an aperture adjacent to the cam lobe, the aperture extending generally normal to an axis of the camshaft, a pin extending through the aperture, and an actuator affixed to the pin for pivotal movement about an axis of the pin, the actuator including a first section arranged to hold the valve in an open position when the actuator exists in an initial position, and a second section arranged to initially retain the actuator in the initial position and to release the actuator from the initial position when the camshaft rotates, the pin being rigidly supported by an inner surface of the aperture in part, wherein a space is defined between the pin and the inner surface of the aperture in the rest part.
A valve cam mechanism for four-cycle engine having a combustion chamber comprising a valve arranged to open and close the combustion chamber to the atmosphere, a camshaft extending generally vertically, the camshaft being arranged for rotation and having a cam lobe to activate the valve, the camshaft defining an aperture adjacent to the cam lobe, the aperture extending generally normal to an axis of the camshaft, a pin extending through the aperture, and an actuator affixed to the pin for pivotal movement about an axis of the pin, the actuator including a holder section arranged to hold the valve in an open position when the actuator exists in an initial position, and a weight section disposed opposite to the holder section relative to the axis of the pin so as to place the holder section in the initial position, the actuator pivoting about the axis of the pin when the weight moves by centrifugal force produced by the rotation of the camshaft so as to release the holder section from holding the valve in the open position, the pin being rigidly supported by an inner surface of the aperture in part, wherein a space is defined between the pin and the inner surface of the aperture in the rest part.
Dependencies are inferred from the claim text.