To implement a constantly stable stratified charge combustion regardless of change in load.
Homogeneous combustion and the stratified charge combustion are performed by switching an injection timing of a fuel, which is directly injected into a combustion chamber from a fuel injection valve11, between an intake stroke and a compression stroke depending on an operation condition. This direct injection type internal combustion engine comprises: an approximately circular cavity 3a arranged at an approximately central part of a piston crown surface; a piston 3 having an annular cavity 3b surrounding the cavity 3a from an outside; the fuel injection valve 11 arranged on a cylinder axial center and injecting a fuel in a hollow conical manner toward the cavities 3a and 3b; and a swirl control valve 13 for generating a swirl flow inside the combustion chamber. In a stratified charge combustion mode and in a load region in which fuel injection is performed such that fuel spray reaches the outside cavity 3b, the swirl flow inside the combustion chamber is intensified as the load becomes lower.
HIRATANI KOJI
KUBO MASAAKI
TSUCHIDA HIROBUMI
TAKAHASHI EIJI
Yoshio Matsuda