Fuel injection pump for compression ignition engine - has stepped piston for independent control of injection duration

摘要

The piston (1) of a fuel injection pump for a compression ignition engine has steps (2,3) to give two separate working chambers (5,6). The end of the pumping phase is determined by separate rings (9,10) controlling the pressure relief holes (7,8). The delivery from both working chambers joins through lines (12,13) via non-return valves (17,18) into a single line at (14). The arrangement provides a simple control for injection duration, independently of the quantity of fuel which is injected.