Next-gen heavy-duty common rail system: Delphi 27 October 2016

A new generation of ultra-high precision, modular common rail injection systems for heavy- and medium-duty commercial vehicle engines (0.7—3.0 litres per cylinder) has been launched by Delphi Automotive.

Principal features of its new F3 systems include: an ultra-fast injector allowing up to nine injection events per cycle; and a new closed-loop control system promising whole-life ‘as new’ performance – all within the existing packaging dimensions.

Kerem Erman, Delphi vice president for powertrain and general manager of the firm’s fuel injection system, says the new system builds on the company’s existing Euro 6 technology.

“At the heart of our strategy is an understanding that best-in-class performance is only attractive if it is combined with the attributes that keep vehicles on the road, working profitably,” states Erman.

“Almost three years since the introduction of our Euro 6 system, which is used world-wide by many of the big vehicle and engine manufacturers, the reliability of Delphi’s very high-precision injectors continues to be exceptional.”

And he explains in particular that the new common rail technology will allow engines to deliver “a substantial improvement” in emissions, fuel economy and refinement, while also maintaining long-term reliability.

That’s partly because at the heart of the new common rail system is a new injector that provides the controller with real-time information on injection operations.

Data from the injector allows closed loop control to continuously optimise injection events, compensating for changing conditions – including wear as the vehicle ages – in real time.

In fact, Erman suggests that the system will allow ‘as new’ injector performance to be maintained for at least 1.6 million km (1.0 million miles).

He also says that closed-loop control eliminates the compromise in injector calibration previously required to allow for drift over its lifetime.

This – and new lightweight 1mm valves developed using ultra-high precision metal finishing techniques, plus proven hydraulic efficiency – allows more and smaller injection events to be specified, he claims. t

Incidentally, he also says that the system removes the need to scan injector characterisation codes when fitting: the information is already held in the injector’s memory and transmitted directly to the ECU.

“Closed-loop control is essential for the next generation of fuel systems, but it has to be achieved without adding complexity,” continues Erman.

“Delphi’s new closed-loop injector for medium and heavy duty applications achieves this with a simple, elegant design that requires no additional wiring.

“We believe this is not only one of the most effective close-loop control solutions, but that through clever design it is also the simplest.”

“The ability to effectively profile combustion means that the need to compromise between CO2, NOx and particulates is greatly reduced,” continued Erman, adding that engines may deliver up to 1.5% fuel efficiency improvement.

“That gives engine designers much greater flexibility in their after-treatment strategies, potentially reducing system costs and allowing a reduction in SCR [selective catalytic reduction] fluid consumption, which can be of significant value to long-distance transport operators.”

While the date of release depends heavily on OEM engine development programmes, Delphi anticipates that first applications for the new F3 common rail system will enter production around 2021.

As with the Delphi’s F2 systems for Euro 6, three common rail architectures will again be available: traditional common rail with a remote pump; EUI-style with a cam-driven pump in selected injectors; and EUP-style with separate pumps driven by a cam in the engine block.

Injector fitment dimensions are also unchanged, allowing integration with existing engines designed for EUI or EUP.

“Delphi’s new system will help vehicle and engine manufacturers meet the toughest global emissions and fuel economy regulations from 2021 and through the next decade,” insists Erman.

“Because our system is modular and evolutionary, it helps minimise engineering costs, reduces component variety and accelerates engineering development. It’s an exciting yet very practical step forward.”

Brian Tinham

Related Companies
Delphi Automotive Systems

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