| 摘要 |
An direct fuel injection spark ignition internal combustion engine comprises a fuel injection valve (11, 11', 11") arranged at a substantially center part of an upper are of a combustion chamber (4), and a piston (3) having a crown surface with a cavity (3a) shaped so that a center axis of a substantially conical-shaped fuel stream injected from the fuel injection valve (11, 11', 11 ") is substantially coincident with a center axis of the piston (3). In a low-load stratified combustion operating region when spark ignition is executed, the fuel injection angle is increased to form a first combustible air-fuel mixture before the fuel stream collides against the cavity of the piston crown surface. In a high-load stratified combustion operating region, the fuel injection angle is reduced to form a second combustible air-fuel mixture after the fuel stream collides against the cavity of the piston crown surface. |
