Patent ID: 7647159

Claim:
A control method for an internal combustion engine that controls a valve timings and lifts of an intake valve and an exhaust valve and a valve duration of the intake valve based on an operating state of the internal combustion engine, the method comprising: executing an absolute value control, wherein, when an engine load is in a high-load zone, the actual values of the valve timings and lifts of the intake valve and the exhaust valve and the valve duration of the intake valve are controlled to coincide with respective target values set based on the operating state of the internal combustion engine; and executing a relative value control, wherein, when the engine load is in a low-load zone, the actual value of a valve overlap amount of the intake valve and the exhaust valve is controlled to coincide with a target valve overlap amount obtained based on the target values, target values being computed as values that permit the internal combustion engine to be appropriately operating when the internal combustion engine is in a steady operating state, decreasing a rate of changing the valve duration of the intake valve when decreasing the valve duration of the intake valve as compared to the rate of changing the valve duration of the intake valve when executing the absolute value control, when the internal combustion engine shifts from a state where the absolute value control is executed to a deceleration state, in which the valve duration and the lift of the intake valve are allowed to be decreasing.