Patent ID: 6267095
Filing Date: 2001-07-31
Classification: F02D,Y02T

Abstract:
An internal combustion engine control apparatus, the engine being capable of switching a combustion mode between a stratified combustion and a homogeneous combustion, and being provided with an EGR device that is prevented from performing EGR immediately after switching the combustion mode from the stratified combustion to the homogeneous combustion, the apparatus comprising:transient condition detection section detecting a transient condition in switching the combustion mode from the stratified combustion to the homogeneous combustion;a residual EGR ratio calculation section calculating, when the transient condition is detected, an actual residual EGR ratio of EGR gas remaining in an intake system of the internal combustion engine;a lower limit value setting section, variably setting a lower limit value of a target equivalent ratio immediately after switching the combustion mode from the stratified combustion to the homogeneous combustion, the lower limit value calculated as a function of the actual residual EGR ratio; anda limiter limiting the target equivalent ratio to the lower limit value immediately after switching the combustion mode from the stratified combustion to the homogeneous combustion.