INTAKE-AIR QUANTITY CONTROL APPARATUS FOR INTERNAL COMBUSTION ENGINES

摘要

The control unit calculates a desired intake-air quantity based on the engine operating conditions, and calculates a threshold limit value that corresponds to a lower limit intake-air quantity above which valve timing control of the intake valve enables the intake-air quantity to be brought closer to the desired intake-air quantity. The control unit calculates a first intake valve timing corresponding to the desired intake-air quantity, and calculates a second intake valve timing substantially corresponding to the threshold limit value. The control units sets a desired valve timing of the intake valve to the second intake valve timing and estimates a desired throttle opening that realizes the desired intake-air quantity by throttle opening control of the throttle valve, when the desired intake-air quantity is below the threshold limit value.