Fuel electro-injector atomizer, in particular for a diesel cycle engine

A fuel electro-injector atomizer for an engine comprising a nozzle having:

• a feedthrough seat that extends along a longitudinal axis;
• a front surface that is external to said feedthrough seat;
• a sealing seat that joins a first surface of said feedthrough seat to said front surface;
• said atomizer further comprising a valve needle comprising:
• a head suitable for coupling with said sealing seat;
• a stem, which has a smaller diameter than said head, axially projects from said head and engages said feedthrough seat;
• said stem and said nozzle radially defining an annular passageway between them, through which a flow of high-pressure fuel can run, and comprising an annular chamber, which axially terminates at said sealing seat;
• said stem comprising an intermediate portion coupled in an axially sliding manner to a second surface of said feedthrough seat;
• said intermediate portion and said second surface delimiting a plurality of channels, each channel of the plurality of channels having a respective outlet in said annular chamber;
• each channel of the plurality of channels comprising a respective channeling portion, which defines a minimum area of passage of said channel and has a cross-section with a depth (P) in a radial direction and an outer chord (C) in a tangential direction along said second surface;
• said valve needle being axially movable along an opening stroke directed axially outwards from said feedthrough seat, starting from a closed position wherein said head is coupled to said sealing seat;
• said sealing seat and said head defining a discharge section, which is annular and has a width that increases as the opening stroke of said valve needle proceeds;
• characterized in that, for at least one of said plurality of channels, the ratio between said depth (P) and said outer chord (C) is greater than or equal to two;
• and
• each channel of the plurality of channels is defined by an outer wall of the stem and sidewalls extending radially outward from the stem and comprises a taper portion disposed upstream of the channeling portion of the channel, considering the direction of fuel towards said sealing seat, and progressively diminishes towards said channeling portion and wherein the channeling portion canalizes fuel flow.