Direct injection diesel engine

摘要

A fuel injection timing of a fuel injector (22) of a direct injection diesel engine is retarded to compression top dead center or even later. All of the required fuel injection amount is injected by the fuel injector (22) in an ignition delay period. The oxygen concentration in the combustion chamber (14) is decreased by exhaust gas recirculation. A swirl is set up in the combustion chamber (14) by a variable swirl generator (31). The compression ratio of the engine is preferably set to 15 or less, the vertical gas velocity in the combustion chamber is reduced by adopting a shallow piston cavity, and the cylinder internal maximum pressure is suppressed to 12MPa or less.