| 摘要 |
PROBLEM TO BE SOLVED: To provide a compression self-ignition engine which smoothly transitions from CI (combustion self-ignition) combustion to SI (spark ignition) combustion without involving abnormal combustion.SOLUTION: An intake passage 20 of an engine includes a high temperature passage 22 provided with heating means (26) for heating intake air, a low temperature passage 23 not provided with the heating means, and flow rate adjustment means (28, 29) for adjusting flow rate of the passages 22, 23, respectively. When the engine operates in a CI area A where CI combustion is performed, a part of the intake air is introduced into an engine body 1 through the high temperature passage 22. When the engine operates in an SI area B, a ratio of the intake air from the low temperature passage 23 is increased. When the engine is in a transitional operation in which an operation point transitions from the CI area A to the SI area B, the SI combustion is performed under a state in which a fuel injection starting time is delayed more than that of normal operation at the SI area A, the injection starting time during this transitional operation is set to be within a range from pre-compression top dead center 45°CA to post-compression top dead center 15°CA. |
