Patent attributes
A direct fuel injection engine has a fuel injection valve that injects fuel toward a cavity formed in a top of a piston, and a spark plug that ignites the fuel-air mixture resulting from the fuel injection. The direct fuel injection engine is configured to strengthen the penetration of the fuel streams, to improve the directionality of the fuel streams and to form in the cavity an agglomerate fuel-air mixture that is homogeneous and has uniform concentration. The cavity preferably has a bottom surface, a curved surface, and a flat surface. The fuel injection valve has a plurality of injection vents that spray solid-core fuel streams with angles formed between adjacent injection vents that are less than or equal to the spray angle of the fuel stream sprayed from each injection vent. The fuel streams form a combined fuel stream having a hollow circular cone shape.