Internal combustion engine fuel injector

A fuel injector (1) for an internal combustion engine; injector terminating in a nozzle for injecting fuel into a corresponding engine cylinder and comprising: - a body hollow (2) extending injector in an axial direction (3); - A control rod (10) axially movable with respect to said injector body (2), to open / close said nozzle; - One servo valve housed in said body controlling injector (2), and comprising: a) an electric actuator; b) a camera control (23) which is bounded axially on one side by said control rod (10), communicates with a fuel inlet (4) and has a discharge conduit (26, 48) comprises a calibrated portion (42, 52); c) a shutter (17) movable axially, under the control of said electrical actuator, between a closed position in which it closes said discharge conduit (26, 48), and an open position in which it opens elmencionado conduit ( 26, 48), to vary the pressure in said control chamber (23) and so produce axial movement of said control rod (10); whereby - said servovalve also comprises an axial rod (33) fixed with respect to said injector body (2), and comprising an outer side surface (34) through which exits said discharge conduit (26, 48); - Said shutter (17) is fitted to said outer lateral surface (34) to slide axially in substantially fluidtight and, in said closed position, closes said discharge conduit (26, 48) so that It is subjected to a resultant axial pressure by the fuel substantially zero; and - said calibrated portion (42, 52) is formed so as to produce swirl and / or cavitation in the fuel discharge area next seal between said shutter (17) and said axial rod (33).