Revolutionary direct acting common rail system

Delphi was given the "Best Technological Innovation in the Automobile Sector" award during the 2009 Barcelona International Motor Show for its direct acting common rail system Delphi Diesel Systems' new Direct Acting Common Rail Injection System won the top award in the "Systems and Components" category in the event organized by the Sociedad de Técnicos de Automoción (STA) and the Show at Barcelona, Spain. The Delphi Direct Acting Diesel Common Rail System is an advanced fuel injection system that features an innovative injection technology. The injector needle is set in motion directly by a piezo ceramic actuator, rather than being moved via an electro-hydraulic circuit. This enables the injector to spray fuel into the combustion chamber faster and with much improved spray atomization and accuracy compared with current diesel fuel injection technologies. The result is a considerable reduction in nitrogen oxide (NOx) emissions (approximately 30 percent versus current injection systems) and more torque and power for better drivability (approximately 10 percent).

While the major elements of the direct acting common-rail injection system include the tubular common rail with high pressure valve (up to 2000 bar); high pressure, modular pump (0.6 to 1.2 cm3/rev) with integrated inlet metering valve, pressure limiter, temperature sensor and transfer pump and an Electronic control unit (ECU) with 32-bit processor, the system is suitable for diesel engine programs for medium- and large-size vehicles to help manufacturers meet European Euro 5 requirements and beyond, and U.S. Tier II Bin 5 emissions standards. Reducing or eliminating the need for costly NOx aftertreatment devices, the direct acting injection system improves injection fuel atomization and speed to help reduce emissions and engine noise, while providing unequalled driving performance. No return flow improves efficiency, enables pump downsizing, and eliminates the need for a return flow fuel cooler.

Having multiple action capability, the ability to deliver small, accurate and stable quantity of fuel ensures consistently low emissions. Enabling operations upto 2000bar pressure, the flexible injection waveform control provides engine designers with unprecedented combustion process capability. This ECU feature enables direct control of the needle lift in the nozzle and, therefore, provides direct control of the rate of injection into the combustion chamber.