Method of operating a fuel injector

摘要

Disclosed is a method of operating a fuel injector 160 of an internal combustion engine 110. The method comprises supplying a first energizing electrical current to an injector solenoid 161, causing the opening of an injector control volume CV and a pressure reduction insaid injector control volume CV, for a first energizing time ET1, which is predetermined to avoid that the pressure in the injector control volume CV approximates a value which would cause an injector needle 163 to raise up and a fuel injection to start. After a predetermined time interval DT a second energizing electrical current 520 is supplied to the injector solenoid 161, for a predetermined second energizing time ET2, which is a function of a rail pressure and a fuel injection quantity. Effectively the first energizing current is used to hold the needle in a position just short of opening for injection and so prime the needle to allow rapid response to the second part which provides the actual fuel injection.