Patent ID: 6378477
Filing Date: 2002-04-30
Classification: F01L

Abstract:
A valve timing control device, comprising:a first rotor of rotating in synchronization with a crankshaft of an internal-combustion engine; a second rotor fixed on an end of an intake camshaft or an exhaust camshaft of the internal-combustion engine and rotatably arranged in the first rotor; a lock member of locking the first and second rotors at a required angle which the second rotor forms with the first rotor; a backward pressure chamber arranged at any one of the first and second rotors, accommodating the lock member and a biasing member biasing the lock member, and having a discharge hole discharging backward pressure of the lock member; and an engagement hole arranged in the other of the first and second rotors, allowing insertion of the lock member, and having an oil hydraulic supply path supplying hydraulic pressure to release the lock member, wherein releasing hydraulic pressure characteristics is provided with hysteresis in that a releasing hydraulic pressure is larger than a holding-releasing hydraulic pressure.