PURPOSE: To keep the pressure in a junction between both main and pilot injection pipes at the time of the injection stop of a fuel pump, constant with a two-way delivery valve, thereby making the next pilot injection easy enough by installing this two-way delivery valve additionally in the main injection pipe to be connected to the fuel pump in parallel with this check valve.
CONSTITUTION: A check valve 16 is installed in a main injection pipe 5 connecting a fuel injection valve 3 of an engine body 1 to a fuel pump 4. On the other hand, a pressure accumulator 12, each of pilot injection starting and finishing control valves 13 and 14, and a retraction valve 15 are installed each to a pilot injection pipe 21 connecting the fuel injection valve 3 to a high pressure pump 11 in a fuel tank 10. These control valves 13, 14 are driven and controlled by a pilot injection controller 18 on the basis of an output signal out of an encoder 20 or the like attached to a crankshaft 6. In a suchlike pilot injection system, a two-way delivery valve 28 consisting of a check valve acting oppositely against the check valve 16 is installed in the main injection pipe 5 in parallel with this valve 16.
IMOTO KOJI
FUKUYOSHI TADASHI
KATAOKA YOICHI
