Patent ID: 7104247

Claim:
A direct fuel injection engine comprising: a combustion chamber having a piston movably mounted therein, the piston including an upper wall having a cavity with a fuel stream directing surface; a spark plug having a spark discharge gap arranged to ignite a fuel-air mixture in the combustion chamber; and a fuel injection valve including a front edge portion with a plurality of injection vents arranged in a vicinity of a center axis of the piston and configured to directly inject fuel into the combustion chamber against the fuel stream directing surface as a plurality of solid-core fuel streams that strike at non-perpendicular angles with the solid-core fuel streams having center spraying axes arranged to form a hollow circular cone shape, the fuel stream directing surface including first and second wall surfaces with the second wall surface curving from the first wall surface toward the fuel injection valve to direct movement of the fuel streams after hitting the first wall surface toward the fuel injection valve, the first wall surface including a surface area where the fuel streams flow after hitting the first wall surface that forms an obtuse angle with the center spraying axes.