| 摘要 |
PROBLEM TO BE SOLVED: To maintain a quantity of exhaust recirculating gas at a target quantity. SOLUTION: An exhaust pipe 23 and an intake introducing pipe 8 are interconnected to each other by a low-pressure EGR passage 42, and a low-pressure EGR control valve 43 is arranged within the low-pressure EGR passage 42. A NOx selection reduction catalyst 27 is arranged within an exhaust passage of an inflowing end 44 downstream of the low-pressure EGR passage 42, and a supply control valve 30 is arranged within the exhaust passage of the NOx selection reduction catalyst 27 upstream. A urea water solution is supplied from the supply control valve 30. When the urea water solution is supplied from the supply control valve 30, an opening degree of the low-pressure EGR control valve 43 is corrected to be reduced compared with when urea solution is not supplied. COPYRIGHT: (C)2009,JPO&INPIT
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