摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve a problem in a fuel-injection type spark ignition engine of the conventional art, wherein many man-hours are needed for forming air-fuel mixture for stratified-charge combustion, and the top surface of a piston is stained too heavily with spray in the stratified-charge combustion to attain a homogeneous combustion. <P>SOLUTION: The spark ignition engine comprises: a cylinder head 10 partitioning a combustion chamber 18; a piston 20 which has a flat top surface 21 and slidably fits in a cylinder head 10; a fuel injection nozzle 31 in which a plurality of orifices 47a, 47b of predetermined diameters are formed for making direct injection into the combustion chamber; and an ignition plug 25 for igniting an air-fuel mixture in the combustion chamber. According to operating conditions of an engine, either a homogeneous combustion mode or a stratified combustion mode is selected. In the stratified combustion mode, a range for a spray from the nozzle 31 is short, and then the spray reaches the plug 25 without the flow direction being changed by the top surface 21 of the piston 20. <P>COPYRIGHT: (C)2004,JPO</p> |