To improve combustion performance in stratified charge combustion in an internal combustion engine.
In a cylinder injection type spark ignition engine having a fuel injection valve installed at a roughly center part of a combustion chamber upper surface and having a cavity shape roughly coaxial with a center axis of fuel spray injected from the fuel injection valve on a piston crown surface, a first combustible fuel air mixture is formed before fuel spray impinges on the piston crown surface at spark ignition timing by enlarging fuel spray angle in a relatively low load operation zone during stratified charge combustion operation, and a second combustible fuel air mixture is formed by making fuel spray angle small and making fuel spray once impinge on the piston crown surface in a relatively high load operation zone during stratified charge combustion operation.
HIRATANI KOJI
KUBO MASAAKI
KAKUHO AKIHIKO
