Patent ID: 6142117
Filing Date: 2000-11-07
Classification: F02D,F02M,Y02T

Abstract:
An engine control apparatus for an internal combustion engine equipped with a combustion system for changing over a combustion condition in the engine among a plurality of combustion modes in accordance with an engine operating condition, and an EGR system for recirculating part of exhaust gas from the engine to an intake air flow into the engine, the engine control apparatus comprising:a first section for producing a first-mode-to-second-mode combustion changeover request signal for requesting a changeover from a first combustion mode to a second combustion mode;a second section for varying an actual equivalent ratio, in response to the changeover request signal, gradually from a first desired ratio level for the first combustion mode to a second desired ratio level for the second combustion mode;a third section for calculating an EGR quantity of the EGR system during a gradual variation of the actual equivalent ratio from the first ratio level to the second ratio level;a fourth section for calculating a modified equivalent ratio in consideration of the EGR quantity; anda fifth section for changing over the combustion condition from the first combustion mode to the second combustion mode in accordance with the modified equivalent ratio.