Patent ID: 7909016

Claim:
A valve timing control apparatus for an internal combustion engine comprising: a variable valve timing mechanism that changes valve timing of at least one of an intake valve and an exhaust valve of the internal combustion engine, the variable valve timing mechanism being driven based on oil pressure; oil pressure control means for controlling the oil pressure that drives the variable valve timing mechanism; target valve timing setting means for setting target valve timing based on an operational state of the internal combustion engine; actual valve timing detection means for detecting actual valve timing; control amount computing means for computing a control amount used for controlling the oil pressure control means, the control amount computing means computing the control amount based on (a) a deviation, which is defined between the target valve timing and the actual valve timing, and based on (b) a hold control amount, which is used for maintaining the actual valve timing at a present state, wherein the oil pressure control means controls the oil pressure based on the control amount computed by the control amount computing means such that the actual valve timing becomes the target valve timing; and learning means for executing a learning operation for learning the hold control amount, wherein: the learning means determines whether a learning execution condition for executing the learning operation is satisfied based on a change direction of the actual valve timing detected by the actual valve timing detection means; and the learning means executes the learning operation for learning the hold control amount when the learning means determines that the learning execution condition is satisfied.