| 摘要 |
PURPOSE:To regulate fuel injection time and quantity in a highly accurate manner by installing a slidable free piston whose one end fronts on a plunger chamber and the other end on the side of a return passage, respectively, in a fuel injection system with a built-in plunger to be reciprocated. CONSTITUTION:An injector 1 is fitted with a needle valve, opening or closing a nozzle 5, free of slide motion in a hole 9 of a fuel injection nozzle 2. In addition, a plunger 3 being reciprocated by a cam (unillustrated herein) interlocking with engine speed is fitted in a hole 11 on the same axis with the hole 9 free of slide motion as well, with which a plunger chamber 13 is expanded or contracted. In the midway of the hole 11, a fuel supply passage 14, a fuel injection passage 15 and a fuel return passage 16 are connected each to the specified position. In this case, a free piston 17 is slidably fitted in a hole 18 lying between the plunger 3 and the needle valve 6, and a low pressure chamber 23 being partitioned in a gap with the needle valve 6 is interconnected to the return passage 16. In this connection, downward displacement of this free piston 17 is regulated by a retainer 21. |
