Patent ID: 8496191
Filing Date: 2013-07-30
Classification: F02M

Abstract:
1. A seal arrangement for a needle valve in a fuel injector for use on an internal combustion engine, the seal arrangement comprising: a nozzle housing having a housing centerline and forming a nozzle cavity; an outer needle valve seat disposed proximate to a distal end of the nozzle housing and along the nozzle cavity, said outer needle valve seat having a generally frusto-conical shape; a plurality of outer nozzle openings formed in the outer needle valve seat of the nozzle housing and arranged around a first position of the housing centerline, the plurality of outer nozzle openings disposed at a first radial distance from the housing centerline; an outer needle valve reciprocally disposed in the nozzle cavity, the outer needle valve having a needle centerline disposed along the housing centerline, the outer needle valve having a seat portion arranged to abut the outer needle valve seat when the outer needle valve is seated; a first ledge formed on the seat portion of the outer needle valve around a first position relative to the needle centerline, the first ledge forming a sharp transition to sealably contact the needle valve seat only along a first line contact seal, the first line contact seal disposed at a first seal radial distance and around a second position relative to the housing centerline; and a second ledge formed on the seat portion of the outer needle valve around a second position relative to the needle centerline, the second ledge forming a sharp transition to sealably contact the needle valve seat only along a second line contact seal, the second line contact seal disposed at a second seal radial distance and around a third position relative to the housing centerline; a bore formed in the outer needle valve, said bore extending axially through the outer needle valve, and an inner needle valve disposed reciprocally within the bore of the outer needle valve; wherein the first housing centerline position of the plurality of outer needle valve openings is between the second and third housing centerline positions of, respectively, the first and second line contact seals.