Internal cylinder intake-air quantity calculating apparatus and method for variable valve open/closure timing controlled engine

Abstract

In apparatus and method for calculating an internal cylinder intake-air quantity for a variable valve timing controlled engine, an air quantity flowing into the intake manifold from an output of an airflow meter is calculated, the airflow meter being installed in an upstream portion of an intake manifold with respect to an intake valve whose at lease closure timing is variably controlled, a cylinder volume of a corresponding cylinder of the engine is calculated, an income and outgo of an air quantity flowing into the intake manifold and a cylinder intake-air quantity flowing from the intake manifold into the corresponding cylinder is calculated to derive an air quantity in the intake manifold, the internal cylinder intake-air quantity is calculated on the basis of the air quantity of the intake manifold and the cylinder volume, and the calculated cylinder volume is corrected on the basis of at least valve closure timing of the intake valve. The calculated internal cylinder intake-air quantity is used to calculate a fuel injection quantity to be supplied to the corresponding cylinder through a fuel injector.