The common rail fuel injection system is the most flexible direct injection system currently available for diesel engines. It differs from other camshaft-driven systems by separating the build-up of pressure from the actual process of injection.
Pressure is delivered by the engine-powered radial plunger pump, which is conveyed in a high-pressure accumulator - the rail.
Electrically-guided injectors introduce the fuel into the combustion chamber. The moment of injection can be selected at will and a single combustion cycle can include up to five injections, factors which have a positive influence on engine sound and fuel emissions.
Small quantities of fuel are injected before the main injection: this significantly reduces ignition delay and noise during the main combustion process.
Thanks to the two-step fuel injection process, the common rail system offers the flexibility necessary for future emission reduction systems.
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