| 摘要 |
PROBLEM TO BE SOLVED: To reduce the injection quantity of insufficiently atomized fuel just after or before the fuel injection of an injector by changing the pressure of the fuel supplied from an accumulating chamber during the injection period of the fuel SOLUTION: The pressure of a common rail 3 is once reduced up to just before fuel injection by driving an electromagnetic relief valve 5 by the control signal from an ECU 8. Therefore, the injection pressure is in a relatively low state in injection start with a low injection ratio, so that generation of insufficiently atomized fuel spray can be minimized. The pressure of the common rail 3 is reduced by the electromagnetic relief valve 5 just before injection end. Since the fuel injection ratio is reduced by this pressure reduction, the quantity of insufficiently atomized fuel spray in short choke area can be reduced. Particularly, the fuel spray in the end of fuel injection is important since it has an influence on the black smoke generation in the latter period of combustion. |
