Patent ID: 7861690

Claim:
A device for controlling an internal combustion engine, having a valve driving mechanism capable of varying the valve-opening characteristic in at least one of an intake valve and an exhaust valve so that the mixture of fuel and air is burnt in the interior of a combustion chamber to generate power, characterized in that the device comprises in-cylinder pressure detection means for detecting an in-cylinder pressure (Pc) within the combustion chamber, intake air pressure measuring means for either detecting or estimating an intake air pressure (Pm), in-cylinder pressure variation amount calculation means for calculating a variation amount of the in-cylinder pressure (Î”Pc) for defining an amount of remaining gas in the combustion chamber due to the valve-overlap of the intake valve and the exhaust valve, intake air amount calculation means for calculating an amount of air sucked in the combustion chamber (Mair) based on the in-cylinder pressure (Pc(Î¸ 2 )) detected by the in-cylinder pressure detection means at a predetermined timing (Î¸ 2 ) during the compression stroke and before an ignition timing and the variation amount of the in-cylinder pressure (Î”Pc) calculated by the in-cylinder pressure variation amount calculation means, ignition means for igniting the gaseous mixture in the combustion chamber, and ignition timing control means for determining the ignition timing (Î¸ig) by the ignition means based on the intake air amount (Mair) calculated by the intake air amount calculation means, wherein the intake air amount calculation means calculates the intake air amount (Mair) by using following formula (where, Î² is a predetermined constant), and M air =Î²Â·( Pc (Î¸ 2 )âˆ’Î” Pc ) the in-cylinder pressure variation amount calculation means calculates the variation amount of the in-cylinder pressure (Î”Pc) based on the intake air pressure (Pm(Î¸ 1 )) either detected or estimated by the intake air pressure measuring means at a predetermined timing (Î¸ 1 ) during the valve-overlap, an exhaust gas pressure (Pe(Î¸ 1 )) at the predetermined timing (Î¸ 1 ) during the valve-overlap, and a gas-passage effective area (S).