Piston for e.g. direct injection engine, has annular tracking zone comprising annular groove generating recirculation movement in zone so that oxygen present in this zone returns towards center of combustion chamber

摘要

The piston (14) has a cavity (10) with a peripheral wall (23) surrounded by an annular tracking zone (24) having an annular groove (30). The groove generates a recirculation movement in the zone so that oxygen present in the zone returns towards center of a combustion chamber. Deeper part of the groove is situated at center of the groove more near to an axis of the piston for inducing the recirculation movement.