Patent ID: 6729563
Filing Date: 2004-05-04
Classification: F02M

Abstract:
A fuel injector comprising:a housing having passageway extending between an inlet and an outlet along a longitudinal axis; a seat having a sealing surface facing the inlet, a first channel surface facing the outlet, and a seat orifice disposed between the sealing surface and the first channel surface; a closure member disposed in the passageway and contiguous to the sealing surface so as to generally preclude fuel flow through the seat orifice, the closure member being coupled to a magnetic actuator that, when energized, positions the closure member away from the sealing surface of the seat so as to allow fuel flow through the passageway and past the closure member; a metering disc proximate the first channel surface so that a virtual extension of the sealing surface onto the metering disc defines a first virtual circle about the longitudinal axis prior to an intersection of the virtual extension with the longitudinal axis, the metering disc including a second channel surface confronting the first channel surface, the metering disc having a plurality of metering orifices, each of the metering orifices having generally parallel surfaces extending through the metering disc generally parallel to the longitudinal axis, the metering disc including a solid imperforate portion within the first virtual circle and all of the metering orifices being located about the longitudinal axis outside the first virtual circle; and a controlled velocity channel being defined by the first and second channel surfaces, the controlled velocity channel having a first portion changing in cross-sectional area as the channel extends outwardly from the orifice of the seat to the plurality of metering orifices, wherein the channel extends between a first end and a second end, the first end disposed at a first radius from the longitudinal axis with the first and second channel surfaces spaced apart along the longitudinal axis at a first distance, the second end disposed at a second radius proximate the plurality of metering openings with respect to the longitudinal axis with the first and second channel surfaces spaced apart along the longitudinal axis at a second distance such that a product of two times the trigonometric constant pi (&pgr;) times the first radius and the first distance is different than a product of two times the trigonometric constant pi (&pgr;) of the second radius and the second distance so that a velocity of fuel flow through the channel varies from the seat orifice to the plurality of metering orifices.