Cylinder head for variable valve timing
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorHironao Takahashi
Life of this patent
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Abstract
A variable valve timing mechanism for an internal combustion engine wherein the camshaft is supported at one end by a combined bearing and valve body member that is detachably connected to the supporting engine body. The connection is such that fluid from the engine lubricating system can be delivered to this body and distributed by a control valve mounted in it. This simplifies machining of the engine body and permits a more compact, lower cost construction without sacrificing any function. The control valve is mounted in a bore that is accessible through the side of the cylinder head and is actuated by a servo motor mounted on the exterior of the cylinder head to provide a compact, rigid and easily serviced assembly.
Claims15
A cylinder head for an internal combustion engine variable valve timing mechanism comprised of a main cylinder head member, a bearing member defining a bearing surface for journaling a corresponding bearing surface of a camshaft, said camshaft having a portion that extends on one side of said bearing member bearing surface, a hydraulically operated, variable valve drive element for changing the phase angle between said camshaft and a camshaft drive element associated with said camshaft portion, a hydraulic conduit extending through said bearing member for supplying controlled hydraulic actuating fluid to said hydraulically operated variable valve drive element, said bearing member being detachably connected to said main cylinder head member independently of fasteners that fix said main cylinder head member to an associated cylinder block, an operating valve element for controlling the supply of hydraulic fluid through said hydraulic conduit mounted in said bearing member, and a valve actuator mounted directly on said main cylinder head member for actuating said operating valve element.
Dependencies are inferred from the claim text.