Injection and mixture formation process and apparatus to implement same

Process for introducing and mixing combustion air and fuel in air compressing, self-igniting, internal combustion engines having a piston crown formed with a rotation-symmetrical combustion chamber having a substantially flat bottom wall and a circumferential side wall, the inner diameter of said chamber increasing in a direction toward said bottom wall, in which combustion air is caused to be rotated about a longitudinal axis of the combustion chamber, and wherein a cylinder head is provided with a fuel injection nozzle in the region of a rim of the combustion chamber at an angle relative to said longitudinal axis and substantially in the direction of rotation of the combustion air, comprising the steps of injecting at least one spray of fuel into said chamber in the direction of air rotation and, in such a manner, that the individual droplets of fuel in said spray are finely atomized in all operating ranges of the engine and a substantially fuel-free zone is formed at the center of said combustion chamber, the radius of said zone being approximately one-third the radius of said chamber;

• and effecting a break-up of said at least one spray in such a manner that the broken-up spray is distributed throughout the zone between said fuel-free zone and said side wall and surrounding said fuel-free zone and generally conforms to the geometry of said side wall of said chamber.