FUEL INJECTION SYSTEM OF INTERNAL COMBUSTION ENGINE

摘要

ABSTRACT A fuel injection system deliberately utilizing after injection so as to improve the engine combustion and reduce soot and NOx, wherein at least one operating valve is provided for operating a first injection port group and second injection port group, after injection is performed consecutively after main injection in a high load region, fuel is injected from the first injection port group and second injection port group at the time of main injection, fuel is injected from the first injection port group at the time of after injection, the actual injection pressure near the first injection port during the after injection period is higher than the actual injection pressure near the first injection port during the main injection period, the operating valve opens the first injection port group to start the injection, then the operating valve opens the second injection port group simultaneously or in a short time as well to perform the main injection, the operating valve closes the second injection port group, then performs the after injection, and the operating valve closes the first injection port group and ends the injection after the elapse of a time longer than simultaneously or a short time from after start of after injection.