Swirl seat nozzle

An injector, comprising:

• a valve seat including a valve seat body having a valve seat upper surface, a valve seat lower surface, and a needle opening formed into the valve seat upper surface, the needle opening having at least one liquid passage and a needle bore sized to permit movement of a valve needle between a lowered position, wherein a lower end of the valve needle forms a seal with a seating surface in valve seat to prevent liquid from flowing out of the at least one liquid passage, and a raised position, wherein the lower end of the valve needle is spaced apart from the seating surface to permit liquid to flow out of the at least one liquid passage;
• and
• a nozzle plate including a nozzle body having a nozzle plate upper surface, a nozzle plate lower surface, and a metering orifice extending between the nozzle plate upper surface and the nozzle plate lower surface;
• wherein the valve seat body includes a plurality of drillings, the plurality of drillings having openings formed in the seating surface and being in flow communication with inlet portions of a plurality of swirl channels, the plurality of swirl channels being configured to deliver fluid from the plurality of drillings to a central swirl chamber in flow communication with the metering orifice, which delivers the fluid from the injector in the form of a spray;
• wherein the plurality of drillings extend at an angle relative to a longitudinal axis from the openings formed in the seating surface to the valve seat lower surface in a continuously linear path through the valve seat to the nozzle plate;
• wherein the plurality of swirl channels is formed into the nozzle plate upper surface;
• wherein one of the valve seat lower surface or the nozzle plate upper surface includes a registration post formed on a surface of the one of the valve seat lower surface or the nozzle plate upper surface, and another of the valve seat lower surface or the nozzle plate upper surface includes a registration bore configured to receive the registration bore to align the inlet portions of the plurality of swirl channels with the plurality of drillings of the valve seat;
• and
• wherein the metering orifice includes an opening formed in a lower surface of the central swirl chamber, a generally conical surface extending from the opening, and an increased diameter outlet surface that terminates at the nozzle plate lower surface.