Patent ID: 6851408

Claim:
A direct fuel injection engine comprising: a combustion chamber; a spark plug positioned in an upper surface of the combustion chamber; a fuel injection valve positioned in a substantially center portion of the upper surface of the combustion chamber, the fuel injection valve being configured and arranged to directly inject a fuel stream inside the combustion chamber; a piston having a guide wall surface being configured and arranged to guide the fuel stream injected from the fuel injection valve; and a controller configured and arranged to control operations of the spark plug and the fuel injection valve, the controller being further configured and arranged to ignite a first air-fuel mixture formed directly after the fuel stream is injected from the fuel injection valve and prior to a majority of the fuel stream being guide by the guide wall surface of the piston when the direct fuel injection engine is operating in a low-load stratified combustion region, the controller being further configured and arranged to ignite a second air-fuel mixture formed after a majority of the fuel stream is guided to an upper portion of the combustion chamber by the guide wall surface of the piston when the direct fuel injection engine is operating in a high-load stratified combustion region.