Fuel injector having valve seat orifice plate with valve seat and drain and re-pressurization orifices

A valve seat orifice plate for a fuel injector comprising:

• a valve seat body defining a center axis, and including a centrally located drain orifice extending between a first axial side and a second axial side of the valve seat body;
• the valve seat body further including a valve seat surface formed on the first axial side and extending circumferentially around the center axis and radially outward of the centrally located drain orifice, and a plurality of flow slots distributed circumferentially around the center axis and extending radially outward of the valve seat surface;
• the valve seat body further including a profiled sealing surface formed on the first axial side and extending circumferentially around the center axis at a location radially outward of the plurality of flow slots, an outer surface extending between the first axial side and the second axial side, and a planar check-facing surface formed on the second axial side and structured to form a wetted wall of a check control chamber in the fuel injector;
• and
• the valve seat body further including a re-pressurization orifice extending between the outer surface and the planar check-facing surface and positioned to refill the check control chamber.

A method of operating a fuel injector comprising:

• moving a control valve in an electrically actuated control valve assembly in the fuel injector from a closed position, in contact with a valve seat of a valve seat orifice plate, to an open position;
• fluidly connecting a check control chamber in the fuel injector to a fuel drain outlet of the fuel injector by way of a drain orifice extending through the valve seat orifice plate, based on the moving of the control valve to the open position;
• moving an outlet check in the fuel injector from a closed position to an open position, where nozzle outlets in the fuel injector are fluidly connected to a nozzle cavity, to spray a fuel from the nozzle outlets, based on the fluidly connecting of the check control chamber to the fuel drain outlet;
• returning the control valve to the closed position;
• returning the outlet check to the closed position;
• and
• re-pressurizing the control chamber with flows of fuel through a first re-pressurization orifice and a second re-pressurization orifice each extending between an outer surface of the valve seat orifice plate and the check control chamber.