Patent ID: 6789414
Filing Date: 2004-09-14
Classification: F02D

Abstract:
An estimation apparatus of an air intake flow for an internal combustion engine comprising:a pressure sensor that detects an intake pressure in a portion just upstream of an intake valve of an intake system of the internal combustion engine; and an air flow meter that detects an air intake flow rate fed from an upstream side of the intake system to the portion just upstream of the intake valve, wherein: a first air intake flow rate fed into the portion just upstream of the intake valve at a predetermined timing prior to a timing for starting fuel injection is obtained based on an output of the air flow meter; a variance in an air intake flow rate caused by a change in the intake pressure in the portion just upstream of the intake valve at the predetermined timing is obtained based on an output of the pressure sensor; a second air intake flow rate fed into a cylinder of the internal combustion engine at the predetermined timing is obtained by adding the first air intake flow rate to the variance in the air intake flow rate; and the second air intake flow rate fed into the cylinder is corrected to a third air intake flow rate required for estimating an actual air intake flow based on an amount of change in the second air intake flow rate fed into the cylinder at the predetermined timing.