| 摘要 |
PURPOSE:To aim at improvements in emission performance at an engine's low load range as well as in output of power at a high load range, by using plural fuel discharge passages properly according to an engine load state, while altering a lift control starting position for a needle valve. CONSTITUTION:High pressure fuel enters a fuel injection nozzle 7 from a fuel- injection pump, then enters a fuel pressure chamber 14 from an inlet 9 via a passage 15, and hereat it forcibly presses a pressure receiving part a 6c of a needle valve 16, lifting it against a spring 17 to open the valve, while the fuel in the chamber 14 passes through a fuel nozzle hole 8 and is fed to an engine's combustion chamber. What is more, pressure in the high pressure fuel entered from the inlet 9 passes a plunger member 18 to the needle valve 16 and controls the valve 16. And, at an engine's low load range, such a state that fuel is spouted at high speed from the fuel injection nozzle hole 8 continues to be long enough so that fuel atomization is well accelerated and unburned gas is reduced in a large measure, thus emission performance is improved. In addition, at a high load range, a fuel injection quantity for an engine is well secured, therefore an injection rate is improved, thus improvements in engine output is promotable. |
