Polymeric bodied fuel injector with a seat and elastomeric seal molded to a polymeric support member

1. A fuel injector comprising:

a polymeric housing having a passageway extending between an inlet and an outlet along a longitudinal axis;

a pole piece disposed in the passageway, the pole piece having a through opening;

a filter assembly having a portion disposed in the through opening of the pole piece;

a coil assembly disposed in the polymeric housing to surround the pole piece;

a spring member disposed partly in the pole piece and including a spring portion contiguous with the portion of the filter assembly;

an armature assembly disposed in the passageway in a first position having a portion confronting the pole piece and in a second position having a closure member contiguous to an end face of the pole piece; and

a metering assembly secured to the polymeric housing proximate the outlet, the metering assembly having a seat secured to a polymeric support member, the seat having a sealing member disposed between the seat and the polymeric support member.

2. The fuel injector of claim 1 , wherein the seat comprises a metallic seat body having first and second ends spaced apart and about the longitudinal axis to define a perimeter about the longitudinal axis.

3. The fuel injector of claim 2 , wherein the perimeter comprises a pocket that retains the sealing member.

4. The fuel injector of claim 3 , wherein the first end comprises a tapered surface contiguous to the closure member and the second end comprises a surface contiguous to a metering disc.

5. The fuel injector of claim 4 , wherein the passageway comprises a plurality of different diameters along the longitudinal axis.

6. The fuel injector of claim 5 , wherein the passageway comprises a portion tapered towards the longitudinal axis to define a guide surface.

7. The fuel injector of claim 6 , wherein the polymeric housing comprises a nylon body enclosing the coil assembly coupled to at least one terminal connector.

8. The fuel injector of claim 7 , wherein the coil assembly comprises a coil housing disposed about the longitudinal axis to surround a bobbin and at least one wire coiled about the bobbin, the coil housing including a flux washer proximal the first external seal and disposed about the longitudinal axis.

9. The fuel injector of claim 8 , wherein the metering assembly further comprises a generally cylindrical member secured to the polymeric support member, the cylindrical member including a central aperture disposed about the longitudinal axis to guide the closure member and at least one aperture offset to the longitudinal axis.

10. The fuel injector of claim 9 , wherein the polymeric support member comprises a surface portion secured to the polymeric bore of the polymeric housing.

11. The fuel injector of claim 10 , wherein the polymeric support member comprises a pocket disposed about the longitudinal axis to surround an outer surface of the polymeric housing proximate the outlet.

12. The fuel injector of claim 11 , wherein the pole piece comprises a resilient element disposed in a bore of the pole piece.

13. The fuel injector of claim 12 , wherein the pole piece comprises a member defining a generally cylindrical outer surface, the generally cylindrical outer surface including a portion of the outer surface closer to the longitudinal axis so as to define at least a recess in the outer surface of the member.

14. The fuel injector of claim 13 , wherein the pole piece further comprises a fuel filter assembly secured to an inner surface of the pole piece, the fuel filter assembly including a filter element and an end face portion spaced apart from the filter element along the longitudinal axis, the end face portion contiguous to a first end of the resilient element.

15. The fuel injector of claim 14 , wherein the filter element comprises a filter element disposed in the polymeric bore so that a gap is provided between the filter element and the bore.

16. The fuel injector of claim 15 , wherein the armature assembly comprises an armature having a radially extending surface contiguous to a second end of the resilient element and a generally cylindrical portion contiguous to the guide surface of the polymeric bore, the armature being secured to a non-magnetic elongated member extending along the longitudinal axis, the closure member contiguous to a sealing surface of the metallic seat in one position of the armature assembly to occlude a flow of fuel through the metering assembly, the closure member extending through the central aperture of the guide member.

17. The fuel injector of claim 16 , wherein the armature assembly comprises an armature having a surface contiguous to another portion of the resilient element and a generally cylindrical portion contiguous to the guide surface of the polymeric bore, the armature being secured to a closure member that engages a sealing surface of the metallic seat in one position of the armature assembly to occlude a flow of fuel through the metering assembly, the closure member extending through the central aperture of the guide member.