PURPOSE: To make the injection period of fuel settable so longer even in a low engine speed range and thereby improve the efficiency of combustion, by installing an injection period control device and interconnecting it to a pressure chamber to be pressurized by a pump plunger in reciprocating motion.
CONSTITUTION: With the reciprocating motion of a pump plunger 24, a fuel- injection pump, which pressurizes the fuel sucked into a pressure chamber 68 via a suction passage 38 and feeds this pressurized fuel to an injection valve via a fuel passage 35, a discharge passage and a delivery valve, etc., is provided with an injection period control device 50 to regulate the injection period. This control device 50 is made up of having each of pistons 72 and 88 fitted slidably into respective bottomed round holes 54 and 76 of a cylindrical body 52 screwed in a housing 14. The piston 72 is energized to the left by dint of a spring 74 and makes a cylinder bore 70, which is open to the pressure chamber 68, so as to cause it to open or close, while the piston 88 is energized to the right by dint of a spring 94, and the round hole 76 is connected to the fuel tank side through a return passage 82.
YANAGIHARA HIROMICHI
WATABE SATORU
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