Control method of a common-rail type system for direct fuel injection into an internal combustion engine

摘要

A control method for a direct fuel injection system (1) into an internal combustion engine (2) provided with a number of cylinders (3); the method presents the stages of: supplying pressurised fuel to a common rail (5) by means of a high-pressure pump (6); cyclically driving a number of hydraulically actuated injectors (4) having an hydraulically actuated needle (21) to inject fuel into the cylinders (3); establishing a desired fuel pressure level within the common rail (5); determining a threshold value (ETmin) for the injectors (4) so that no fuel is injected by each injector (4) if it is driven for a time interval shorter than the threshold value (ETmin); and reducing the actual fuel pressure within the common rail (5) by driving the injectors (4) for a driving time interval (ETred) shorter than the threshold value (ETmin).