News; Delphi Common Rail System

Published: Thursday 18 August, 2011



“Delphi is at the forefront of emissions-controlled technology”



Delphi Diesel Systems has been involved in Common Rail technology from the beginning. Some of the very first systems were pioneered by Delphi with systems fitted to, among others, Ford, Jaguar, Renault, Peugeot-Citroen, Mercedes-Benz, Nissan, SsangYong, Kia and Hyundai applications. The number of vehicle manufacturers fitting Delphi's Common Rail systems continues to grow, with new contracts regularly being announced.

Delphi Diesel is committed to supporting vehicle manufacturers and the automotive aftermarket in harnessing this growing market, with total Delphi Diesel Common Rail parc expected to reach 14 million vehicles by 2011.



 



Emissions

With European emissions regulations for new light duty vehicles (cars and light commercial vehicles) getting tighter and tighter, it is imperative that the Common Rail system meets these requirements.

European emissions standards are evolving regularly and Delphi has always reacted accordingly to ensure that its Common Rail systems meet the latest requirements, and are in a position to be at the forefront of emission-controlled technology. The current European emissions standard is Euro IV, with Euro V coming soon. The accompanying table shows movement through the European standards.



 



The Future

From the current environmental and market trends, it is easy to see why Common Rail technology is going to play a major part in the business of everyone involved in diesel vehicles. Delphi has made a substantial investment in preparing its authorised distributors to deal with the new technology, both in new Common Rail product technology and in diagnostics, equipment and training. With increasing numbers of vehicles equipped with Delphi components coming out of warranty, this spells exciting opportunities in the future.



A Common Rail engine is designed to supply constant fuel pressure to electronically controlled injectors, meaning the fuel supply is not dependant upon engine speed.



The system is made up of a number of components, with each performing a role that is vital to the overall running of the system. The high pressures (up to 2000 bar) inherent in Common Rail systems mean that any fault must be diagnosed and the faulty component replaced immediately. Failure to do so can result in prolonged damage to the system and engine.

The accompanying diagram depicts the layout of the Common Rail system and the placement of many of the components within it.



 



Common Rail Pumps



The demand for reduced emissions and improved performance means that diesel fuel injection has come a long way since the rotary pump product of yesteryear. The Common Rail system has now put the new generation of diesel engines on a par with petrol engines.

A Common Rail engine is designed to supply constant fuel pressure to electronically controlled injectors through a shared fuel reservoir. This means that the fuel supply is not dependant on engine speed.



At the heart of the Common Rail system is the fuel pump. This is a vital component which generates the high pressure within the system. The pump receives the fuel from the tank via the filter, and then passes it under pressure to the rail, via a pipe. Delphi Common Rail pumps are fitted to a number of OE applications including Ford, SsangYong, Mercedes-Benz, PSA and Renault.



 



Common Rail Injectors



The objective of the Common Rail injection system is to be able to control the advance,injection duration and pressure individually, in a way that manages the combustion perfectly-cylinder by cylinder-depending on the working conditions of the engine.The Common Rail injector is a vital component within the system, regulating the exact amount of fuel that is delivered into the combustion chamber. The precise opening and closing of the injectors is electronically controlled by electrovalves that are installed in each nozzle holder body. Delphi Common Rail injectors are fitted to a number of the most popular vehicles of the world's largest vehicle manufacturers, including Renault, Ford and Kia.



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