A Fuel Valve for Pilot Oil Injection and for Injecting Gaseous Fuel into the Combustion Chamber of a Self-Igniting Internal Combustion Engine

摘要

A fuel valve (50) for pilot oil injection and for in j ecting gaseous fuel in to the combus t ion chamber o f a self-igni ting internal combus t ion engine. The fuel val ve comprises an elongated fuel val ve housing (52) w i th a rear end and a front end, a nozzle (54) with nozzle holes (56), a gaseous fuel inlet port (53) for connection to a source ( 60) · o f pressurized gaseous fuel and an axially displaceable val ve needle ( 61) having a closed pos i t ion and an open position and resting on a seat ( 69) in the closed position and thus preventing flow from the gaseous fuel inlet port (53) to the nozzle (54). In the open pos i t ion the axially displaceable needle ( 61) has lift from the seat (69) thereby allowing flow from the gaseous fuel inlet port (53) to the nozzle (54). The fuel valve further comprises an actuator system for controllably moving the axially displaceable valve needle (61) between the closed pos i t ion and the open pos i t ion, a pilot oil port ( 7 8) for connection to a source o f pilot o il, a pilot oil injection conduit (67) extending axially inside the axially displaceable needle ( 61) and a pump chamber (80) with an inlet fluidly connected to the pilot oil port ( 7 8) and an outlet connected to a first end o f the pilot oil supply conduit (67). The pump chamber (80) contracts when the axially displaceable needle ( 61) is moved from the closed pos i t ion to the open pos i t ion and the pump chamber (80) expands when the axially displaceable needle (61) is moved from the open position to the closed pos i t ion. A second end o f the pilot o il injection conduit (67) is fluidly connected to the nozzle (54) so that pilot oil is del i ve red to the nozzle (54) when the pump chamber (80) contracts.