| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress the lowering of the output of an engine due to the rise of an exhaust gas pressure while suppressing the discharge of PM into the atmosphere in a spark ignition engine in which a PM filter is adopted. <P>SOLUTION: In this spark ignition engine in which the PM filter is adopted, when an air/fuel ratio is smaller than a specified value (a), the combustion configuration of the engine is determined to be a uniform rich combustion, and the flow ratio of exhaust gases passed through the PM filter is increased as the air/fuel ratio is increased (S1, 2). When the air/fuel ratio exceeds the prescribed value (a), the combustion configuration of the engine is determined and, the exhaust gases are controlled so as to be passed through the PM filter since a PM amount is large in the exhaust gases in stratified lean combustion (S3, 4). In a homogeneous combustion (homogeneous stoichiometric or lean-combustion), the exhaust gases are controlled so as to be passed through a bypass passage since PM is not almost present in the exhaust gases (S3, 5). <P>COPYRIGHT: (C)2004,JPO</p> |
