Medium Duty Diesel Common Rail (DCR) System - Delphi

Description
To meet future stringent emissions requirements and to offer
further improvements in fuel economy, Delphi Diesel Systems, one
of the world’s largest producers of fuel injection equipment, has
developed a high-pressure fuel injection system—the Delphi Diesel
Common Rail (DCR) system.
Fuel injection equipment with the capacity of operating at very high
pressure is required to meet ultra-low emissions challenges and
low noise demands. The latest developments made to the DCR
system extend capabilities to medium-duty and commercial vehicle
applications.
Product Design
The medium-duty DCR is a modular system, and can be easily adapted
for different engines. The main components of the DCR system are:
• Common pressure accumulator (the “rail”)
• High-pressure regulator (optional)
• Inlet-metered high-pressure supply pump, with integrated lift pump
• Electronically actuated injectors
• Electronic control unit
• Filtration unit
The DCR system consists of a common pressure accumulator, called
the “rail.” Rail designs vary from those mounted along the engine
block, or for smaller engines a spherical accumulator unit can be
fitted. The rail is fed by a high-pressure pump.
The pressure level of the rail is electronically regulated by a combination
of metering on the supply pump and fuel discharge by a highpressure
regulator (when fitted). The pressure accumulator operates
independently of engine speed or load, so that high-injection pressure
can be produced at low speeds if required.
A series of injectors are connected to the rail, and each is opened
Commercial Vehicle Systems
Medium Duty
Diesel Common
Rail (DCR) System
and closed by a solenoid, driven by the electronic control unit (ECU),
which can be mounted on the engine or on the vehicle.
Applications
The medium-duty DCR system has been developed to meet the
demanding requirements for medium truck and off-highway engine
applications.
Because of the compact, modular design of the DCR system it can
be applied to a wide range of engine applications from three to
eight cylinders.
Product Features
• Injection pressure independent of speed
• High-pressure “multiple” injections per combustion event
• Reduced NO x emissions and engine noise
• Modular system, easily adapted to different engine types
• Compact design
• Full electronic control and interface with other vehicle or
engine functions

Medium Duty
Diesel Common Rail (DCR) System
DCR Advantages
• Compact design—The compact design of the injector outline
enables the DCR system to be used on two or four valves-percylinder
engines.
• Modular system—With one electronically driven injector per
engine cylinder, the system is modular and can be used on
three to eight cylinder engines.
• Low drive torque—As the pumping pressure to the rail is not
phased with the injection, the DCR system requires a low drive
torque from the engine.
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• Independent injection pressure—The injection pressure is independent
of the engine speed and load, enabling high pressures at low speed
if required.
• Multi injections per firing cycle—Injection sequences which include
periods both pre- and post-main injection can be utilized to reduce
emissions, particularly NO x , enabling the system to meet the stringent
emission levels required by Euro-3 and US-98 legislation and
beyond. The inclusion of pilot injection also results in significant reduction
in engine noise.
• Full Electronic Control—DCR offers all the benefits of full electronic
control fuel metering and timing, as well as the option to interface
with other vehicle functions.
Delphi Energy & Chassis Systems
5820 Delphi Drive
Troy, MI 48098