Method of controlling an injection dwell time between two injections of a fuel injector

摘要

Method and apparatus of controlling the hydraulic dwell time DThyd between a first injection P and a second injection M performed by a fuel injector. The method comprising the steps of: determining a value of a nominal electric dwell time DTel between the first injection and the second injection, this is the period between the closing signal being sent and an opening signal being sent; determining an actual instant of hydraulic closing of the fuel injector F after the first injection, this is when the physical fuel injector closes; calculating a corrected electric dwell time as a function of the nominal electric dwell time and the actual instant of hydraulic closing of the fuel injector after the first injection; operating the fuel injector using the corrected electric dwell time. This method of control allows for correction to a control strategy similar to Injection Quantity Fusion(IQF)/Hydraulic fusion called Zero Hydraulic Interval (ZHI). The correction can help to deal with deterioration to the fuel injector to factors such as age drift. The actual instant of hydraulic closing can be estimated from the energising time of the injector.