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Delphi introduces 2,700 bar heavy-duty common rail injection system

7 September 2012

Delphi Automotive has entered production of its newest common rail fuel injection system with up to 2,700 bar pressure capacity for heavy-duty engines designed for Euro VI applications and other demanding global emission standards. The company also introduced a low cost, 1,800 bar common rail system designed for China 4/5 applications.

Euro VI Systems. The new systems provide a choice of three architectures: (1) conventional remote pump common rail (F2R) and two common rail systems with distributed pumps, (2) F2E for overhead cam-driven pumps and (3) F2P for pumps driven by a cam in the block. Working at up to 2,700 bar, they combine the high-pressure capability of Delphi's EUI/EUP systems with the 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 require minimal changes to engine architecture, according to Delphi.

Each of these three systems will enter production between now and mid-2013 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. To achieve this, “significant investments” were made at the Delphi facilities in Stonehouse and Sudbury in the UK, said the company. The system was developed at Delphi Heavy-Duty Diesel Technical Centre in Park Royal, London, UK.

The challenge faced in the design was to ensure a million-mile durability combined with the high pressures and very fine tolerances required to provide the required performance. 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.

This approach has also helped enable “significant improvements” in hydraulic efficiency. Increased efficiency, while providing reductions in fuel consumption and CO2, also reduces heat generation in critical areas of the system, preventing fuel degradation and deposits, especially when running with high biofuel contents. The high efficiency designs of the injectors and the pumping elements also result in smaller, lighter components.

The injector features 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, it could be made from high grade materials formed using super-clean powder metallurgy. This allows greater precision with reduced wear and greater resistance to high combustion temperatures. Significant benefits were also achieved from targeted use of new, multi-layer coatings, said Delphi.

China 4/5 System. The new system—optimized for the requirements of emerging markets—comprises a high-pressure pump, rail assembly, electronic controller and injectors. Suitable for engines with a displacement of 9 to 16 liters, the system provides a maximum rail pressure of 1,800 bar, allowing compliance with China 4/5 emissions standards. The system has been optimized for cost, local manufacturability, an affordable upgrade to future emissions standards, diverse fuel qualities, robustness and fuel economy.

The fuel pump uses a modular design that eliminates unnecessary capability for the market, resulting in potential cost savings. This strategy also simplifies manufacturing and allows each module to be upgraded as technical requirements change. The lower rail pressure, which creates less fatigue, has allowed cost-optimization of the materials and the manufacturing process. The pressure control valve and electronic control unit also are simplified, as is the electronic control unit, which provides diagnostics and other functionality appropriate to the system performance.

Next Generation Systems. Delphi continues to investigate the next generation of technologies for applications beyond 2020. With developments in valve technology that are already working in the laboratory, Delphi currently provides systems that are capable of operating at up to 3,000 bar, and is investigating higher pressures.

These announcements by Delphi follow the recent introduction of a 2,500 bar system by Delphi‘s competitor Bosch.

Source: Delphi