Patent ID: 7055490

Claim:
An in-cylinder injection, spark ignited internal combustion engine including an ignition plug arranged substantially at a center of an upper portion of a cylinder, a fuel injection valve injecting fuel into the cylinder substantially in a sector having a relatively small thickness and spreading substantially in a vertical direction, and a piston, and switching between homogenous combustion by the fuel injected in an intake process and stratified combustion by the fuel injected in a compression process, said fuel injection valve being located at a perimeter of the upper portion of the cylinder, said piston having a top surface with a cavity biased in location to be farther from the perimeter of the cylinder where said fuel injection valve is located than from the perimeter of the cylinder opposite said fuel injection valve, said cavity having a wall opposite said fuel injection valve deviating toward the cylinder's substantial center, the fuel sprayed and thus injected for said stratified combustion through said fuel injection valve into said cavity.