A New Lift-Controlled Piezo Injector for the Next Generation of Common Rail Diesel Injection Systems for Passenger Cars

Multiple injection is potentially capable of reducing emissions of common-rail diesel engines at part load. The slope of the needle lift of today’s hydraulically operated common-rail injectors is very weak. For that reason, the fuel flow is throttled in that phase and the mixture formation suffers. The presented injector, which is directly actuated by a piezo, shows the same very steep needle lift as a unit injector. This results in a better mixture formation. A needle lift control allows to open orifices at different levels and to adjust homogenisation.

The hardware in the loop simulation shows the exact needle lift control and its influence on the mixture formation.