Engine fuel injector

摘要

A fuel injector for an engine includes a continuous endoskeletal injector tube enclosing an imperforate continuous passage for fuel flow from an inlet end to an outlet end of the tube. A valve seat, injection valve, tubular magnetic pole, biasing spring and adjusting sleeve are mounted within the tube, optionally with other elements, all being exposed to fuel in the passage defined by the tube. A solenoid coil and a magnetic body together with mounting components and seals are mounted on the exterior of the tube where they are protected from exposure to the fuel, which is restricted to passage within the continuous tube. The body, pole and armature form a magnetic flux concentrating path operative to attract the armature to the pole and open the valve when the coil is energized. The solenoid coil may be preassembled with its connector in a body forming a separate coil assembly for subsequent installation on the injector tube. During assembly, the tubular pole may be adjusted to set the desired stroke of the injection valve prior to fixing the pole in the tube. Various other features are also disclosed.