Piezo injector for common-rail systems

Operation of the piezo injector

The rapidly switching piezo injector allows short injection intervals which inject into the cylinder the amount of fuel required for economical combustion, independent of the driving situation. Up to ten individual injections are possible per injection cycle. In addition, the injection process can be designed with high flexibility. Using multiple injections, the engine's fuel consumption and CO₂, pollutant, and noise emissions can be reduced.

Control is via a piezo actuator made of several hundred layers of a piezo ceramic. The ceramic expands by a few thousandths of a millimeter as soon as voltage is applied, setting the jet needle in motion. This coupling of actuator and nozzle needle enables the very short reaction times and very small preinjection quantities.