| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent emission of NOx of high concentration while adequately changing the combustion mode between the stoichiometric combustion mode and the lean combustion mode according to the engine load. <P>SOLUTION: An engine system has conduction state changing means 2, 12a, 12b, which change the conduction state of exhaust gas E to one side of a first conduction state for conducting the exhaust gas E to a first exhaust passage 5a having a first storage reduction catalyst 11a and a second conduction state for conducting the exhaust gas E to a second exhaust passage 5b having a second storage reduction catalyst 11b during the stoichiometric/lean combustion change for changing the combustion mode from the stoichiometric combustion mode to the lean combustion mode, changes the conduction state of the exhaust gas E to the other side of the first flow state and the second conduction state during the lean/stoichiometric combustion change for changing the combustion mode from the lean combustion mode to the stoichiometric combustion mode, and changes the conduction state of the exhaust gas E between the first and second conduction states during the change to the stoichiometric combustion mode. <P>COPYRIGHT: (C)2012,JPO&INPIT |
