PURPOSE: To carry out optimum fuel injection corresponding to an engine condition further with simplified constitution and to ensure durability.
CONSTITUTION: Fuel is forcibly fed to a valve chamber 4 from a plunger 2 through a high pressure passage 19. The high pressure passage 19 is branched halfway and connected to also a pressure reducing chamber 24. A needle valve 5 in the valve chamber 4 is energized in a direction of closing an injection port by a spring 15. A spill valve 26 is pressed to an opening part of the pressure reducing chamber 26 by a spring 27 and a solenoid 35. The spill valve 26 is adjusted to a valve opening pressure higher than the needle valve 5, and when a pressure in the high pressure passage 19 is increased, first the needle valve is lifted to inject fuel. Thereafter, when the spill valve 26 is opened, the pressure in the high pressure passage 19 is instantaneously decreased, and the needle valve 5 is lowered down to cease injection (pilot injection completed). Energizing force of the solenoid 35 is controlled in accordance with an engine condition to adjust completion timing of the pilot injection.
KOBAYASHI TOMOKI
YASUDA JUNJI
