摘要 |
<p>A controller sets a negative valve overlap period, during which both of an intake valve and an exhaust valve are closed, such that not all the burned gas is discharged from the combustion chamber. When switching the combustion mode from the spark ignition combustion to the HCCI combustion, the controller executes following operations a), b), and c): a): switching the intake lift amount from a first intake lift amount to a second intake lift amount, such that intake opening timing is delayed relative to an exhaust top dead center; b): switching the exhaust lift amount from a first exhaust lift amount to a second exhaust lift amount after the operation a); and c) delaying the exhaust closing timing relative to a reference exhaust closing timing, such that the internal EGR amount is generated.</p> |