Method for determining the injection law of a fuel injector using a roller-test bench

摘要

A method determines an injection law of a fuel injector to be tested in an injection system and includes steps of: completely interrupting feeding of fuel from a fuel pump to a common rail; avoiding opening of all injectors except for one to be tested; measuring initial pressure of the fuel inside the rail before starting the opening of the injector; opening the injector for consecutive openings with a same test-actuation time; measuring final pressure after ending the opening; determining a pressure drop in the rail during the opening (equal to a difference between the initial and final pressures); estimating, according to the pressure drop, a fuel quantity that is actually injected by the injector when the injector is opened for the time; and causing an internal-combustion engine using the system to rotate by an external actuator during the openings to allow execution of consecutive openings with the same time.