The internal EGR amount estimation method for an engine, the variable valve control method, the ignition timing control method and the cylinder intake air quantity calculation method of using the said internal EGR amount estimation value

摘要

PROBLEM TO BE SOLVED: To estimate internal EGR amount with high accuracy. SOLUTION: A basic value of internal EGR amount without overlapping is calculated (S2), and when overlapping, increasing correction amounts (S5, S6, S7) due to overlapping calculated by considering overlap time, a center crank position thereof, and intake air pressure are added to calculate internal EGR amount (S8). A target closing timing of an intake air valve is calculated to a target air amount correcting valve obtained by adding the internal EGR amount to a calculated target air amount (S1).