| 摘要 |
PROBLEM TO BE SOLVED: To improve the engine output and the rate of fuel consumption by properly controlling the ignition timing even when the amount of intake air supplied in a cylinder is suddenly changed. SOLUTION: A cylinder pressure P0 in the exhaust stroke of a cylinder #i to be ignited, and cylinder pressures P1 to P3 for every specified crank angle in the intake stroke, are read (S13 to S16 or S17 to S20), and pumping loss torque Tp is calculated based on the differential pressure between the cylinder pressure P0 detected at the time of exhaust stroke, and the cylinder pressures P1 to P3 for every specified crank angle in the intake stroke (S21). The inverse number of the pumping loss torque Tp is corrected by using an atmospheric correction factor Kp, namely a correction factor for the air density, or atmospheric factor, etc., to set a representative value L (S23), and a basic ignition timing ADVBASE is set by map retrieval based on the representative value L and the engine speed NE (S24). Since the basic ignition timing is set based on the change in the cylinder pressure from the exhaust stroke to the intake stroke of the cylinder #i to be ignited, the representative value L which corresponds to the amount of intake air actually supplied into the cylinder, can be obtained without being affected by abrupt change in the amount of intake air. |
