Premetered pump injector having constant injection pressure, and derivative system

摘要

A pump injector sends a premetered quantity of fuel to a needle type injector of the type including a piston and a discharge chamber. The injector includes a compression piston mechanically controlled by cam or eccentric having any form. The compression piston compresses fuel within a compression chamber. An injection piston is activated exclusively by the pressure within the compression chamber, opposed by an opposing return spring. The injection piston in turn compresses the fuel in an injection chamber designed to feed the injector. A pressure regulator limits the pressure in the compression chamber to a high, preset value independent of the speed and load of the engine.