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

摘要

A fuel injector (1) has an injector body (2) and a control rod (10), which is movable in the injector body (2) along an axis (3) to control the opening/closing of a nozzle that injects fuel into a cylinder of the engine; the injector body (2) houses a metering servovalve (5) having a control chamber (26), which is axially delimited by the control rod (10) and communicates with an inlet (4) and with a discharge channel (42); the metering servovalve (5) is provided with a shutter (47), which slides axially on an axial guide (38), from which the discharge channel (42) exits, to open and close the discharge channel (42) and, in consequence, vary the pressure in the control chamber (26); the discharge channel (42) has at least two restrictions (53,44) having calibrated passage sections and arranged in series with each other to divide the pressure drop along the discharge channel (42).