Delphi Technologies’ new ultra-high-precision fuel injector, with a valve just 1.0 mm in diameter, is now in pilot production. The DFI 21 injector, for medium and heavy-duty diesel applications, is produced using new manufacturing techniques that enable improved aerospace tolerances to be delivered in conjunction with automotive volumes and pricing.
The DFI 21 injector is built on the technology of the F2 Euro VI system to provide a substantial improvement in emissions, fuel economy and refinement.
The ultra-lightweight of the new 1.0 mm valve helps the DFI 21 injector deliver up to nine injection events per cycle, compared with two or three for a typical Euro VI system. The improved control means peak temperatures, and hence NOx, can be reduced; allows multiple pilot injection, which enhances refinement by slowing the rate of pressure rise. It enables multiple post-injection events reducing soot formation.
Delphi’s F3 system adds closed-loop compensation for any minute variation between the characteristics of individual injectors. This enables the use of smaller injection events because the closed-loop system ensures they will remain accurate throughout the engine’s design life of typically 1.6 million km.
F3 is the first Delphi common rail system family to cover both heavy duty and medium duty engines, using a range of modular sub-systems that allow applications from 0.7 litres per cylinder up to 3.0 litres per cylinder.
Delphi Technologies is currently manufacturing beta-level samples of the DFI 21 in batches of several hundred, using production-representative processes that are readily scalable.