Patent ID: 6386175
Filing Date: 2002-05-14
Classification: F02B,F02M,Y02T

Abstract:
The method of forming a combustible fuel mixture for a spark ignition internal combustion engine, the engine having a cylinder block with a plurality of cylinder bores formed therein, the cylinder bore defining a longitudinal axis, a plurality of substantially flat top pistons each reciprocally housed within a cylinder bore, a cylinder head attached to the block and closing top ends of the bores to form a plurality of combustion chambers, an intake port formed in the cylinder head and communicating with the combustion chamber via an intake valve for introducing air into the combustion chamber, a fuel injector, defining an axis and communicating with the combustion chamber, for supplying fuel into the combustion chamber, and an ignition source communicating with the combustion chamber for igniting fuel within the combustion chamber, with said method comprising the steps of:injecting fuel from the fuel injector having an outlet and a predetermined initial cone angle, into the engine at a predetermined velocity, said injected fuel impinging on a surface adjacent the outlet of said injector thereby forming a cloud shallowly penetrating the combustion chamber so as to float therein to reduce wall wetting, said impingement surface having a substantially spherical surface positioned approximately 1.25 mm from the outlet of said injector so substantially all of said jet strikes said surface; urging said cloud upwardly in said combustion chamber with said substantially flat top piston during a compression stroke of the engine; wherein said mixture comprises a stratified mixture and said cloud defines a relatively rich region and the remainder of the volume of the combustion chamber defines a lean region, with said fuel remaining substantially unmixed with said inducted air, thereby producing said stratified charge as said piston moves said cloud toward said ignition source.