Patent ID: 6460496
Filing Date: 2002-10-08
Classification: F01L

Abstract:
A valve timing control device, comprising:a first rotor rotatable in synchronization with a crankshaft of an internal-combustion engine and having a plurality of shoes formed at an inner periphery of the first rotor; a second rotor fixed at an end of an intake or exhaust camshaft of the internal-combustion engine, arranged in the first rotor, rotatable relative to the first rotor, and having a plurality of vanes formed at an outer periphery of the second rotor; an advance side hydraulic chamber and a retardation side hydraulic chamber formed between the vanes of the second rotor and the shoes of the first rotor; a locking member locking either of the first and second rotors with respect to the remainder at a required angle; an accommodation hole arranged at either of the first and second rotors, accommodating the locking member and a biasing means biasing the locking member, and having a discharge hole discharging a backward pressure exerted on a back section of the locking member to outside; and an engagement hole arranged at the remainder, allowing the insertion of the locking member; an unlocking hydraulic chamber; and an unlocking hydraulic pressure supply path supplying a hydraulic pressure to the unlocking hydraulic chamber; wherein at least one of the advance and retardation side hydraulic chambers is equipped with a purge path communicating to the atmosphere.