Patent ID: 11939932
Assignee: VITESCO TECHNOLOGIES GMBH
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 13:
14. A method for determining a static flow rate of a piezo-electric injector of a combustion engine injection system, the piezo-electric injector comprised of a needle and a piezo-electric actuator that controls a valve of the injector, the injection system also including an electric generator that sends electric current pulses to the piezo-electric actuator of the injector, and a voltage sensor that measures voltage values at terminals of the piezo-electric actuator, the method comprising the steps of:
determining a duration between an instant of closure of the valve and an instant of closure of the needle; and
determining a temperature of the engine;
determining an engine speed; and
if i) the determined duration between the instant of closure of the valve and the instant of closure of the needle is greater than a predetermined threshold, ii) the temperature of the engine is between a first predetermined temperature and a second predetermined temperature, and iii) the engine speed is between a first predetermined speed of rotation and a second predetermined speed of rotation, then:
sending, via the electric generator, an electric current pulse to the piezo-electric actuator, such that the piezo-electric actuator contacts the valve without opening the valve, the electric generator sending the electric current pulse during a time of an injection cycle of the injector when the needle is returning from an open position to a closed position,
measuring, via the voltage sensor, a plurality of voltage values of the piezo-electric actuator, and
determining the static flow rate of the piezo-electric injector based on the plurality of voltage values measured of the piezo-electric actuator.