This part of ISO 7876 establishes a vocabulary for common rail (CR) fuel injection systems for diesel (compression-ignition)
engines and their components.
The terms defined in this part of ISO 7876 are unique to common rail fuel injection systems; terms and definitions relating
to other fuel injection systems are to be found in the other parts of ISO 7876.
2 Terms and definitions
2.1
common rail [fuel] injection system
CR [fuel] injection system
high-pressure fuel injection system, characterized by a component, the
rail
(2.8), which supplies the individual
CR injectors
(2.5) with highly pressurized fuel and reduces pressure pulsation in the high pressure
system
Note 1 to entry: It is also characterized by the following features:
-
— the rail pressure may be varied independently from engine speed and load and is electronically
controlled;
-
— the start and the end of the injections are controlled by an electronic valve at the
CR injector;
-
— the energy for the injections is supplied to the CR injectors via a rail with highly
pressurized fuel;
-
— the injections occur directly from the rail.
2.2
fuel feed pump
low-pressure pump delivering fuel from the tank via one or several filters to the
high-pressure-generating components
2.3
high-pressure supply pump
mechanically driven pump of any configuration (gear pump, piston pump etc.) which
is able to deliver the necessary amount of fuel at the highest required pressure
Note 1 to entry: This pump may include a device or devices for regulating the delivered quantity of
fuel to the
rail
(2.8).
2.4
internal transfer pump
2.5
CR [fuel] injector
fuel injector that includes the features of a conventional fuel injector and, additionally,
a device for controlling the start and end of the injection, e.g. by means of a solenoid-operated
or piezo-driven valve
Note 1 to entry: The CR injector may or may not contain a pressure amplifier for the injection pressure;
the amplifier is actuated by highly pressurized fuel.
Note 2 to entry: For the definition of conventional fuel injector, see ISO 7876-2.
2.6
pressure control valve
electrically actuated spill valve in the high-pressure system designed to control
and vary the pressure in the
rail
(2.8) to the required values depending on speed and load of the engine
2.7
volumetric control valve
2.8
rail
high-pressure storage chamber with the twin functions of supplying the
CR injectors
(2.5) with fuel and reducing pressure pulsation in the high-pressure system caused by the
individual injections
Note 1 to entry: It may be manufactured as a separate part (e.g. a tubular device) attached to the
engine or may be a channel within the cylinder head.
2.9
flow limiter
device located between the
rail
(2.8) and each
CR injector
(2.5) designed to shut off the fuel flow in the pipe if the maximum permitted flow is exceeded
2.10
flow damper
device located between the
rail
(2.8) and each
CR injector
(2.5) designed to moderate the fuel pressure pulsation in the pipe caused by each injection
2.11
[CR] pressure sensor
2.12
pressure limiter
safety valve designed to limit the operating pressure to the maximum permitted pressure
2.13
electronic control unit
2.14
inlet throttling device
inlet flow control valve