Patent ID: 8651074

Claim:
A variable valve timing device which varies valve timing by changing relative rotational phase between a camshaft for operating an intake valve or an exhaust valve and an output shaft of an engine, the device comprising: a first rotor which rotates with either one of the camshaft and the output shaft; a second rotor which rotates with the other one of the camshaft and the output shaft; a rotating mechanism which adjusts the valve timing of the intake valve or the exhaust valve by relatively rotating the rotors; a restriction mechanism which selectively provides a restricted state in which relative rotation of the rotors is restricted in a predetermined restricted range and an enabled state in which relative rotation of the rotors is enabled to an outside of the restricted range, the restriction mechanism including a movable restriction member which provides the restricted state by being moved to a restricting position when a predetermined restricting condition is satisfied, and the enabled state by being moved to an enabling position when a predetermined enabling condition is satisfied; and a stuck determination unit which determines that the restriction member is stuck in an abnormal state when the restricting condition or the enabling condition is satisfied and the restriction mechanism does not provide the restricted state or the enabled state corresponding to the satisfied condition, wherein the restriction mechanism includes: a pin provided as the restriction member, the pin being projected at a projected position provided as the restricting position, and being retracted at a retracted position provided as the enabling position, and a slot which provides the restricted state by being engaged with the pin which is in the projected position, and provides the enabled state by being disengaged with the pin which is in the retracted position, the stuck determination unit includes a retracted stuck determination unit which determines that the restriction member is stuck in the retracted position when the restricting condition is satisfied and the restriction mechanism does not provide the restricted state.