Piston for use in spark ignition engine, has hollow zone with two symmetrical portions extending parallel to axial plane and perpendicular to axis of symmetry to form two oblong half-cavities which extend from ignition control

摘要

The piston has an upper surface (16) and an axis of symmetry cutting the upper surface in a central part. The upper surface has a hollow zone to form a cavity. The hollow zone has two symmetrical portions extending parallel to an axial plane (P) and perpendicular to the axis of symmetry to form two oblong half-cavities (24, 26) which extend symmetrically from an ignition control (40). An independent claim is also included for a spark ignition engine having a piston.