Patent ID: 7762222
Filing Date: 2010-07-27
Classification: F01L

Abstract:
1. A variable valve timing controller adjusting a valve timing of an intake valve and/or an exhaust valve by varying a speed of an electric motor relative to a rotational speed of a camshaft in such a manner as to vary a camshaft phase representing a rotational phase of the camshaft relative to a crankshaft of an internal combustion engine, the variable valve timing controller comprising: a target motor speed computing device configured to compute a target motor speed based on a rotation speed of the internal combustion engine and a deviation between a target camshaft phase and an actual camshaft phase; a motor drive controller configured to feedback control a motor current representing a driving current of the motor in such a manner as to decrease a deviation between the target motor speed and an actual motor speed; a motor current estimating device configured to estimate the motor current based on at least the target motor speed and the actual motor speed; and a motor current restricting device configured to restrict the motor current when the motor current estimated by the motor current estimating device exceeds a specified value.