FUEL-INJECTION SYSTEM FOR AN INTERNAL-COMBUSTION ENGINE

摘要

A fuel-injection system (2) for an internal-combustion engine has at least one fuel injector (1) with a fuel-metering servo valve (9) for controlling the discharge of fuel from a metering chamber (12); the fuel pressure in the metering chamber (12) controls an open/close needle (7) for carrying out fuel injections into a cylinder; an electronic control unit (11) issues two electrical commands (S1, S2) separated by an electrical dwell time (DT), one for carrying out a pilot injection (P) and one for carrying out a main injection (M), such that the main injection (M) starts before the pilot injection (P) ends, while the open/close needle (7) remains at a lift value in which the fuel flow rate is negligible; in particular, the second electrical command (S2) is issued during a rebound phase (T) of an open/close element (15) of the fuel-metering servo valve (9).