Patent attributes
A piston in a direct injection spark ignition internal combustion engine is configured to reciprocate upward and downward within a combustion chamber along a reciprocating axis. The piston comprises an upper end which partly defines the combustion chamber; a bowl defined on the upper end of the piston, the bowl having an at least partially curved sidewall region extending upward from a bottom surface of the bowl, the bowl being configured so that fuel injected laterally into the bowl toward the curved sidewall region from an injection side of the bowl is directed along the curved sidewall region and upward toward a spark plug of the internal combustion engine, where the bowl has a converging contour in which a curvature of the converging contour is greater at a portion of the contour near the spark plug than a portion of the contour near the injection side of the bowl.