| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrain the advance of serial clogging by suitably coping with increase in pressure loss due to clogging in the case of applying a particulate scavenging filter to an engine having a variable capacity type turbocharger. <P>SOLUTION: The clogging ratio RTO _ ADPF indicating the decrease proportion of an equivalent area is estimated from a pressure difference before and behind the particulate scavenging filter (S315). A target exhaust emission flow rate TQEXH is obtained from a target fresh air quantity tQac_corp_cont and the fuel injection quantity QFVNT (S303), and a target nozzle opening is obtained according to two maps (S304, S306) (S307). A correction value KRAV_ADPF is obtained from a turbine outlet pressure PEXH_TCOUT (S314) and clogging ratio RTO_ADPF (S316) and multiplied (S308). When the particulate scavenging filter 29 is clogged, the target nozzle opening TRAV is corrected to become larger, thereby restraining an increase in pressure on the exhaust turbine inlet side, which forms back pressure of an engine to restrain a rise of an internal EGR rate due to residual gas. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
