Fuel injector assembly including a blow-back prevention cam

摘要

A unit injector assembly (2, 40) of the cam actuated, open nozzle type is disclosed in which an extremely compact injector body is actuated by a cam lobe (42) having a stepped profile for causing fuel to be metered into an injection chamber (52) of the injector (2) without blow back of gas into the supply passage (66) feeding fuel to the injector. The invention is characterized by an injector body (4) having a minimum number of internal flow passages (66, 72) designed to reduce the complexity and cost of manufacture of the injector and having an exterior shape designed to form a fuel supply flow path (22) and an isolated fuel drain flow path (24) between the exterior surface of the injector body (4) and the interior surface of the recess (6) in which the injector (2) is designed to be received.