Fuel pump-injector unitary assembly for internal combustion engine

摘要

A fuel pump-injector unitary assembly comprises a plunger slidable in a bore and provided with a longitudinal passage-way, in combination with a metering ring surrounding the plunger and housed in an annular chamber of the injector body. The plunger is movable into a first or upper postion in which fuel is admitted into the lower part of the injector bore through an inlet port, and a second or lower position in which the tapered lower end of the plunger obturates fuel spray nozzles provided at the bottom of the bore. Fuel metering results from the cooperation of an inclined ramp of the ring with a fuel discharge duct transversely extending through the plunger and connected with the longitudinal passage-way thereof. Relative rotation of the metering ring and of the plunger permits adjustment of the injected fuel charge.