Patent ID: 7725244

Claim:
A control apparatus for an internal combustion engine which is operated in a plurality of combustion modes including a torch self ignition combustion mode which involves changing a remaining amount of previously burnt gas generated within a cylinder as an internal EGR amount by an internal EGR device, forming an air-fuel mixture including both a stratified air-fuel mixture and a homogeneous air-fuel mixture by a fuel injection by a fuel injection device, burning the stratified air-fuel mixture with a spark ignition, and burning the homogeneous air-fuel mixture with self ignition using the burning stratified air-fuel mixture as a torch, said control apparatus comprising: internal EGR control means for controlling the internal EGR amount by diving said internal EGR device; actual internal EGR amount parameter calculating means for calculating an actual internal EGR amount parameter indicative of an actual internal EGR amount which is an estimate of the internal EGR amount, said actual internal EGR amount parameter calculated based on an actual exhaust closing angle of an exhaust valve in the internal combustion engine; target internal EGR amount parameter calculating means for calculating a target internal EGR amount parameter which is a target for the actual internal EGR amount parameter; index value calculating means for calculating one of a relative deviation and ratio between the calculated target internal EGR amount parameter and the calculated actual internal EGR amount parameter, as an index value; fuel injection amount calculating means for calculating fuel injection amounts for producing a homogeneous air-fuel mixture and for producing a stratified air-fuel mixture, respectively, and calculating the fuel injection amount for producing a stratified air-fuel mixture in accordance with the calculated index value when in the torch self ignition combustion mode; and fuel injection control means for injecting a fuel of the calculated fuel injection amount for producing a homogeneous air-fuel mixture at a timing for producing a homogeneous air-fuel mixture, and injecting the fuel of the calculated fuel injection amount for producing a stratified air-fuel mixture at a timing for producing a stratified air-fuel mixture by driving said fuel injection device, wherein said fuel injection amount calculating means include correcting means for correcting, when the index value indicates that the target internal EGR amount parameter exceeds the actual internal EGR amount parameter in the torch self ignition combustion mode, the fuel injection amount for producing the stratified air-fuel mixture to be larger as the exceeding degree is larger.