Method and system for injecting a pilot fuel into a combustion chamber

摘要

The fuel injection system is provided with a control device for controlling the pilot fuel injection phase to be less than ten percent of the main fuel injection phase. In one embodiment, an injection pump is constructed with a piston having a part with a pair of bevelled edges which control the start and end of injection as well as a tension spring for abruptly moving the piston in the delivery stroke. In another embodiment, a control device includes a rotatable spool which has a cross-bore for communicating cyclically with a pair of radial bores in a surrounding sleeve and which, in turn, communicate with oppositely disposed bores in a casing in order to deliver a flow of pilot fuel during the injection phase.