Patent ID: 6467446
Filing Date: 2002-10-22
Classification: F01L

Abstract:
A variable valve timing system for a vehicle, comprising:an intake camshaft for operating an intake valve; an exhaust camshaft for operating an exhaust valve; an intake cam sprocket mounted on the intake camshaft; an exhaust cam sprocket mounted on the exhaust camshaft; a chain interconnecting the intake cam sprocket and the exhaust cam sprocket; and means for varying phase angles of the intake and exhaust camshafts by, according to an engine rpm, pushing and pulling the chain to forcedly rotate the intake and exhaust cam sprockets at a predetermined angle while moving in the perpendicular direction with respect to longitudinal direction of a power transmission member; wherein the means for varying comprises: an auxiliary chain sprocket disposed between the intake and exhaust cam sprockets and engaged with the chain; and means for moving the auxiliary chain sprocket in a perpendicular direction with respect to a longitudinal direction of the chain to push and pull the chain in the perpendicular direction, thereby varying the phase angles of the intake and exhaust camshafts.