Fuel Injection Systems to Power the Next Generation of Commercial Vehicle Engines English Free Members only

Euro VI saw two dominant trends emerge in Fuel Injection Equipment for heavy duty commercial vehicles. This paper will describe the main drivers behind these trends, how they are diversifying beyond Euro VI, and the flexible products Delphi has developed to satisfy the market’s needs. The development of high efficiency SCR after-treatment systems has led to the possibility to achieve Euro VI without EGR. This approach drives quite different requirements on the fuel injection characteristics when compared to a heavy EGR strategy, namely injection pressure and rate shape, driving the need for flexibility in the fuel injection system. Beyond Euro VI a third approach is expected, where a strategy with heavy EGR and heavy SCR is used to reduce emissions even further. Three embodiments of the Delphi F2 Heavy Duty Diesel Common Rail System developed for Euro VI are in production today. These three embodiments share common hydraulic principles and core injector architecture whilst allowing the necessary flexibility of injection characteristics and fuel system packaging. It will be shown that Delphi has built on this modular approach with the next generation of F3 fuel systems, providing a clear upgrade path for the engine builder. Central to the F3 system is the development of a new injector architecture resulting from further miniaturisation of the proven 3-way control valve concept employed today. This concept results in significant improvements in control and consistency with close to zero leakage, enabling the full exploitation of complex multiple injection strategies ultimately resulting in improved trade-offs between fuel consumption, emissions and noise.