Spray control with non-angled orifices in fuel injection metering disc and methods

A seat subassembly comprising:

• a seat, the seat including a sealing surface, an orifice, a first channel surface, a terminal seat surface and a longitudinal axis extending therethrough;
• a metering disc contiguous to the seat, the metering disc including a second channel surface confronting the first channel surface, the metering disc having a plurality of metering orifices extending generally parallel to the longitudinal axis, the metering orifices being located about the longitudinal axis and defining a first virtual circle greater than a second virtual circle defined by a projection of the sealing surface onto a metering disc so that all of the metering orifices are disposed outside the second virtual circle;
• and
• at least one channel formed between the orifice and the metering disc, the channel extending at a taper between a first end and second end, the first end contiguous to the second seat orifice portion at a first radius from the longitudinal axis, the second end disposed at a second radius with respect to the longitudinal axis, and a virtual extension of the taper extending towards the longitudinal axis forms an apex located at distance less than the first distance such that a flow of fuel between the orifice and the metering disc exiting through each of the metering orifices forms a spray angle oblique to the longitudinal axis.

A method of controlling a spray angle and distribution area of fuel flow through a fuel injector, the fuel injector having an inlet and an outlet and a passage extending along a longitudinal axis therethrough, the outlet having a seat and a metering disc, the seat having a seat orifice extending between a first orifice portion and a second orifice portion generally parallel to the longitudinal axis, and a first channel surface extending obliquely to the longitudinal axis, the metering disc including a second channel surface confronting the first channel surface so as to provide a frustoconical flow channel, the second channel surface being located at a first distance from the first orifice portion, the metering disc having a plurality of metering orifices extending therethrough and located about the longitudinal axis, the method comprising:

• adjusting (a) a taper angle of the frustoconical channel so that a virtual extension of the taper towards an apex located at a distance less than the first distance to the second channel surface, and (b) a ratio of a thickness of the metering disc relative to an opening diameter of the metering orifice so that a spray angle of a flow path exiting the metering orifice is a function of at least one of the taper angle and the ratio;
• and
• locating the metering orifices at different arcuate distances on a first virtual circle outside of a second virtual circle formed by an extension of a sealing surface of the seat so that a spray distribution of a flow path exiting the metering orifice is a function of the location of the metering orifices on the first virtual circle.