Patent ID: 6311901
Filing Date: 2001-11-06
Classification: F02B,F02M,Y10T

Abstract:
A fuel injector having an inlet, an outlet, and a passageway providing a fuel flow conduit from the inlet to the outlet, the fuel injector comprising:a needle positionable in the passageway between a first position occluding the passageway and a second position permitting fuel flow; anda seat contiguously engaging the needle in the first position, the seat having an upstream face, a downstream face, and a passage extending along an axis between the upstream face and the downstream face, the passage defining a portion of the passageway and including:an orifice portion proximate the downstream face and having a first transverse cross-sectional area relative to the axis; the orifice portion extending along the axis a prescribed length and including a right circular conical section having a prescribed diameter, and wherein a ratio of the prescribed length over the prescribed diameter being at least 0.3;a needle-sealing portion proximate the upstream face and having a second transverse cross-sectional area relative to the axis that decreases at a first rate in a downstream direction from a first area to a second area; anda transition portion interposed between the orifice portion and the needle-sealing portion and having a third transverse cross-sectional area relative to the axis that decreases at a second rate in the downstream direction from the second area to the first transverse cross-sectional area.