Delphi starts to produce new heavy-duty common rail system

The new systems provide a choice of three architectures, allowing vehicle manufacturers to select the best solution for their engines: conventional remote pump common rail (F2R) and two common rail systems with distributed pumps; F2E for overhead cam-driven pumps and F2P for pumps driven by a cam in the block. Working at up to 2,700 bar, they combine the proven high-pressure capability of Delphi’s popular EUI/EUP systems with the fast, high-pressure fuel delivery over the entire range of speed, timing and load that can be achieved with common rail. For engine designers upgrading existing EUI or EUP power units, the two distributed pump systems offer an ideal progression with minimal changes to engine architecture. 

“Between now and mid-2013, we will be entering production with each of these three systems for customers launching ranges of new and revised engines from 9 to 16 liters. Delphi secured three contracts for these systems for a lifetime value expected to exceed 3.7 billion euros,” said David Friday, Delphi Diesel Heavy-Duty managing director. “To achieve this while retaining Delphi’s outstanding record for consistent high quality, we have made significant investments in our facilities around the world, including our sites in Stonehouse and Sudbury in the U.K.”. 

With the new systems entering production, Delphi has released information on the technical innovations developed at its Heavy-Duty Diesel Technical Centre in Park Royal (London, U.K.) that enable compliance with Euro VI, NA13, Japan PPNLTR and Final Tier 4B, alongside improved fuel economy and simplified exhaust aftertreatment compared with alternative solutions to these demanding standards. 

“The big challenge was ensuring million-mile durability combined with the ultra-high pressures and very fine tolerances required to provide the required performance,” said David Draper, Delphi Diesel Systems engineering director. “Achieving this at an affordable cost meant taking a new approach to the design and manufacture of many of the components. The partnership with our manufacturing specialists was central to the success of this program.” 

Design flexibility and high-precision 

Delphi’s strategy has been to develop a unique, highly modular system, which brings multiple benefits. The distributed pump systems introduce the first application of specialized outlet metering valves in each pumping element. This provides flexible capacity to accommodate different engine ranges/families by adding or subtracting pumping elements and also accommodates selectable displacement by utilizing some or all of the installed pumping elements as required to match the immediate demand. The base design has also been future proofed, providing engine designers with flexible upgrade steps as their requirements evolve,” Draper explained. 

The design flexibility and high-precision provided by this approach has also helped enable significant improvements in hydraulic efficiency. “Inefficiency not only increases fuel consumption and CO2 emissions but leads to heat generation in critical areas of the system, potentially causing fuel degradation and deposits, especially when running with high biofuel contents,” Draper said. “Again, the partnership with our manufacturing specialists has allowed us to make incremental improvements in a number of areas, providing what we believe is now the most efficient system available.” 

The high efficiency designs of the injectors and the pumping elements also result in smaller, lighter components and configurations, bringing further improvements in packaging and and reduced loads that allow further reductions in the cost and weight of selected engine components. 3/3 

“The injector is a good example of the partnership between our design and manufacturing teams,” added Draper. “It is now a modular construction so that each segment can be manufactured from a material optimized for its function. Because the nozzle tip is now so small, we are able to use precious materials formed using super-clean powder metallurgy. This allows greater precision with reduced wear and greater resistance to high combustion temperatures. We have also achieved significant benefits from targeted use of new, multi-layer coatings.” 

Next generation ultra-high-pressure systems 

The team continues to investigate the next generation of technologies for applications beyond 2020. “We have some very exciting developments in valve technology already working in our laboratories and are talking with customers about ultra-high efficiency systems that are more tightly integrated with the engine.” said Friday. 

Delphi currently provides systems that are capable of operating at up to 3,000 bar, and is investigating higher pressures. “Our focus is on greater efficiency and more precise control, which may avoid the need for the costs associated with higher pressures, but Delphi has world-leading expertise in this field that we intend to continue developing so that our customers have complete flexibility in their design decisions.” 

Delphi Powertrain supplies complete diesel fuel injection systems for light-, medium- and heavy-duty applications in all world markets. Delphi also supplies gasoline fuel injection and engine management electronics and is at the cutting-edge of developments in power electronics for electric and hybrid vehicles.