SUMMARY
An operating process for engines with spark ignition and direct fuel injection engines which ensures the formation of a stratified lean fuel-air charge under the modes of partial loads and the power composition of the fuel-air mixture at high loads has been developed.The design of a two-stroke spark-ignition engine was modernized by installing a direct fuel injection system, placing the nozzle in the cylinder wall, and changing the combustion chamber shape.A procedure of adjustment of the composition of the fuel-air mixture in the cylinder of a two-stroke spark-ignition engine has been developed. The procedure features the recording of engine parameters and indicators at a constant cycle fuel feed and intake air adjustment. The proposed procedure makes it possible to more accurately adjust the composition of the fuel-air mixture due to a more accurate dosage of air than the cycle fuel feed.Experimental studies were carried out and adjustment characteristics were constructed in terms of the air-fuel mixture composition in the cylinder of a two-stroke engine with a developed operating process.Load characteristics (at n=3,000 rpm) of rational adjustment in terms of economy and maximum power were constructed based on data on the adjustment characteristics for the composition of the fuel-air mixture.It was found that in terms of the load characteristic of rational economy adjustment, the composition of the fuel-air mixture in the engine cylinder (?cyl.ec) varied from 1.31 to 1.94 and the minimum fuel consumption was ge min=259 g/(kWh). In terms of the load characteristic of rational power adjustment, the composition of the fuel-air mixture in the engine cylinder (?cyl.pow) varied from 1.31 to 1.7, and the fuel consumption at partial loads was ge=270 g/kWh.Characteristics of airflow rate depending on the cycle fuel feed can be used to change the composition of the fuel-air mixture with automatic adjustment of the engine load