Combustion chamber for reverse tumble spark ignition direct injection engine

摘要

Superior piston bowl and combustion chamber configurations are designed for a reverse tumble spark ignition direct injection engine. The piston includes a shallow bowl extending from adjacent an edge of the piston head to an inner side slightly beyond a peak. The bowl features a bowl lip re-entrant angle at the spark plug location having an open or positive re-entrant angle. On lateral edges of the bowl between the inner and outer edges, wing like extensions include negative re-entrant angles. These help contain the injected fuel within the bowl during combustion. Other features of the combustion chamber include vertical intake ports that produce a weak reverse tumbling air flow motion with a tumble ratio of about 0.6, which allows increased flow efficiency of the port. An injector spray cone angle of 90 degrees is preferred with a bowl sized to capture the spray. Various additional features are disclosed.