Fuel injector equipped with a metering servovalve for an internal combustion engine

A fuel injector for an internal combustion engine, the injector ending with a nozzle to inject fuel into an associated engine cylinder and comprising:

• a hollow injector body extending along an axial direction;
• a metering servovalve housed in said injector body and comprising:
• an electro-actuator;
• a control chamber communicating with a fuel inlet and with a fuel discharge channel, the pressure in said control chamber controlling the opening/closing of said nozzle;
• a shutter axially movable in response to the action of said electro-actuator between a closed position, in which an outlet of said discharge channel is closed, and an open position, in which the discharge channel is open, to vary the pressure in said control chamber;
• wherein said discharge channel comprises three restrictions having calibrated passage sections and arranged in series with each other so as to cause respective pressure drops when said discharge channel is open, said calibrated passage sections of each of the three calibrated restrictions restricting fuel flow in both directions, said restrictions spaced apart from one another by enlarged intermediate segments of the discharge channel that extend between adjacent ones of the restrictions, each of said enlarged intermediate segments having a cross-sectional area that is larger than a cross-sectional area of the restrictions that it extends between;
• wherein said restrictions are defined by respective bodies that are distinct from each other.