Abstract: A method of air metering is provided for obtaining a desired air flow through a fuel injector. The fuel injector comprises an air assist injector valve body and an air assist backup washer, having two or more flow channels, contained within the backup washer. The fuel injector further comprises a shroud member having a flat surface, abutting up against the backup washer so the flat surface of the shroud member combined with the flow channels in the backup washer meter and/or direct the air flow.

Abstract: An air assist top feed fuel injector having a nozzle end for delivering fuel to an engine induction passage includes a retainer shroud on the injector nozzle end for directing air adjacent the nozzle end for atomizing the fuel. In a preferred embodiment, the retainer shroud is an integral member including an interconnected end cap, a central seal retainer and a connecting sleeve between the cap and retainer. The member directs assist air around the nozzle to atomize the fuel and retains lower and central seal rings that prevent leakage from or into the air passages. Alternative embodiments include separate end cap, upper ring retainer and lower ring retainer members or integral upper and lower retainer members that coact to similarly direct and prevent leakage of assist air.

Abstract: An engine fuel injection system includes a conventional fuel rail with a top feed fuel injector connected thereto. The overall length of the injector is able to be shortened by the application of compact fuel inlet filter mountings in which a well (deep cup) shaped filter element is positioned to overlap one or both of (1) an adjusting tube within the injector body and (2) a space between the end of the injector fuel inlet tube and the interior of the associated fuel rail. The filter may be fixed within the injector to the adjusting tube or the inlet tube or may be fixed externally of the injector to the fuel rail. Various exemplary embodiments are shown and described.

Abstract: A bottom feed engine fuel injector is provided with a valve spring calibration adjuster such as an adjusting tube, which permits fuel flow from the top of the injector during manufacturing calibration and run in. The upper end of the injector is capped in the last manufacturing step after calibration to prevent fuel passage through this opening in normal engine use where bottom fuel feed is used in conventional fashion. Several exemplary adjusters and top feed closing embodiments are illustrated and described. The modified injector structure and manufacturing process reduces costs by allowing both top and bottom feed injectors to be assembled and calibrated on the same manufacturing equipment.

Abstract: A ferromagnetic housing that encloses the electromagnetic coil to form part of the stator is fabricated from uniform thickness sheet metal to have a cylindrical neck that fits onto the ferromagnetic fuel inlet tube of a top feed fuel injector, a shoulder extending outwardly from the neck and a cylindrical body extending from the shoulder to circumferentially bound the electromagnetic coil. A single through-hole is provided in the housing to provide for passage of both electrical terminals from the electromagnetic coil.

Abstract: A non-ferromagnetic member is disposed between, and joined to, a ferromagnetic fuel inlet tube and a ferromagnetic valve body structure. The valve body structure is fitted to the non-ferromagnetic member by telescoping the upper axial end of the valve body structure over the O.D. of the lower end of the non-ferromagnetic member and by guiding the armature on a cylindrical guide surface in a bore of the valve body structure at a location that is axially below the axial location where the upper end of the valve body structure and the lower end of the non-ferromagnetic member telescopically engage. For given part tolerances and given tolerances in tooling that is used to assemble the parts, closer tolerance in parallelism of the impacting armature end surface to the impacted fuel inlet tube end surface is obtained.

Abstract: A non-metallic cylindrical shell is fitted to the exterior of a metallic valve body portion of a solenoid-operated fuel injector to cover otherwise exposed metal that exists between a lower O-ring seal proximate the nozzle and a non-metallic overmold that covers the solenoid and an adjoining portion of the valve body. The shell and the cover come together at a joint where they mutually axially overlap in such a manner that assures both coverage of the exposed metal and retention of the shell on the valve body for the full tolerance stack-up range of the various parts when assembled.

Abstract: Multiple stacked orifice disk members cooperatively form a chamber space through which fuel is constrained to pass as it flows from the valve seat to the nozzle. Orifices in one member that communicate the chamber space to the fuel flow are larger and perform primarily a turbulent flow creating function while orifices in another member that communicate the chamber space to the fuel flow are smaller and perform primarily a metering and targeting function. Thus, turbulence and metering functions are segregated from each other. In certain embodiments at least one more orifice disk member is sandwiched between the first two to divide the chamber space in one or more smaller chamber portions while still providing fluid communication between such portions, such added disk member(s) contributing either one or both functions of turbulence or better metering and targeting. In certain embodiments, all orifices are equal so that each contributes to turbulence, metering, and targeting.

Abstract: A non-metallic overmold covers the solenoid and an adjoining portion of a valve body shell, leaving another portion of the valve body shell exposed. This exposed portion contains a circumferential groove in its outside surface that is held by a portion of a mold that molds the cover. This prevents the inside surface of the valve body shell from having to be contacted.