SINGLE ACTUATOR FUEL INJECTOR FOR DUAL FUELS

摘要

Fuel injectors are disclosed that are capable of simultaneously delivering liquid and gaseous fuels to the combustion chamber (33) of a compression ignition engine. The fuels are delivered to the needle control valve cavity (32) sequentially via separate passageways. The delivery of the pressurized liquid fuel is actuated by the single actuator that is provided for each fuel injector (10). A liquid fuel check valve (34), in combination with the actuator, controls the delivery of the pilot liquid fuel to the needle control valve cavity (32). The gaseous fuel is supplied at a lower pressure than the liquid fuel, after the liquid fuel is delivered to the needle control valve cavity (32) and the gaseous fuel is supplied to the fuel injector (10) without a separate actuator. A check valve (34) in the gaseous fuel passage (28) closes the supply (27) of gaseous fuel when the pressure in the needle control valve cavity (32) rises to a predetermined level as liquid fuel is charged to the cavity (32) after an injection event.