| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel economy improvement effect by lean combustion and a reduction in pumping loss and a further increased fuel economy improvement effect by suppressing the occurrence of knocking. SOLUTION: This controller of a spark ignition engine 1 comprises a special operation mode. In the special operation mode, the controller is brought into a two-cylinder connected state so that a gas discharged from a preceding cylinder 2A is led into a succeeding cylinder 2B and the exhaust gas is led into an exhaust gas passage 20, stratified combustion is performed at a lean air-fuel ratio in the preceding cylinder 2A, and the burned gas is led into the succeeding cylinder 2B and uniform combustion is performed together with the newly fed fuel. The controller comprises an air-fuel ratio control means, an ignition control means, and a knocking detection means. During the special operation mode, a compression self-ignition causing an assisted ignition is performed in the succeeding cylinder 2B to increase the EGR rate of the succeeding cylinder 2B in a high load side area. Also, an ignition assisted-retard is performed to increase knock resistance. When knocking is detected, the air-fuel ratio of the preceding cylinder 2A ia changed to a rich side. COPYRIGHT: (C)2005,JPO&NCIPI |
