Patent ID: 6782859
Filing Date: 2004-08-31
Classification: F01L,F02B

Abstract:
A valve system for an OHV four-cylinder internal combustion engine, said engine including a pair of cylinder banks disposed symmetrically on opposite sides of an imaginary line orthogonal to an axis line of a crankshaft, wherein each of said cylinder banks includes a crankcase portion for rotatably supporting said crankshaft, a cylinder block portion on an outside of said crankcase portion, and a cylinder head portion on the outside of said cylinder block portion, and said cylinder head portions enclose respective combustion chambers, said valve system comprising:a plurality of intake and exhaust valves for opening and closing intake and exhaust ports of said combustion chambers being provided at said cylinder head portions; a plurality of valve camshafts including at least one intake valve camshaft and at least one exhaust valve camshaft operating in connection with said crankshaft, said valve camshafts being rotatably supported at said crankcase portions; said camshafts being fixed to driven gears, said crankshaft being fixed to a driving gear, said driven gears being driven by said driving gear through idle reduction gears; a plurality of valve-operating members for operating said intake and exhaust valves; and a plurality of oscillating arms operating in connection with said valve camshafts being connected with said valve-operating members through pull rods disposed respectively on lateral sides of said cylinder banks.