EGR CONTROL METHOD OF ELECTRONICALLY CONTROLLED DIESEL ENGINE

摘要

PURPOSE: To prevent unstable operation of EGR while suppressing the narrow EGR control region and the EGR shortage as much as possible. ;CONSTITUTION: A diesel engine 2 is provided with an EGR passage 54, an EGR valve 55, and an electric vacuum regulating valve(EVRV) 56. The ECU 71 computes the basic final injection based on the engine speed or the like, and the basic final injection is corrected so as to eliminate the variance of the speed fluctuation in the combustion cycle for each cylinder, and the final injection for each cylinder is computed. The ECU 71 drive-controls a fuel injection pump 1 based on the final injection. The ECU 71 computes the EFR quantity based on the basic final injection or the like before being corrected for each cylinder, and the EVRV opening is regulate-controlled based on the computed EGR quantity. Thus, the fluctuation of the EGR command value for each cylinder to regulate the opening of the EVRV is suppressed, and frequent ON/OFF switching of the EGR valve 55 is suppressed.;COPYRIGHT: (C)1993,JPO&Japio