cover feature
Bosch Diesel: Economical,
Clean and Powerful
Wherever you are in the world, diesel vehicles have become a familiar sight on our streets. In Western Europe,
nearly one in two newly registered cars is a diesel. Bosch has played a decisive role in this development with its
diesel systems, such as the common rail system and the unit injector system. These Bosch innovations ensure
full power development as well as clean and efficient fuel combustion in modern diesel engines.
Common rail injection: advanced technology for diesel engines
B
osch launched the first common rail system in 1997. The system is named after the shared high-pressure reservoir
(common rail) that supplies all the cylinders with fuel. With conventional diesel injection systems,
the fuel pressure has to be generated individually for each injection.
Bosch Diesel
With the common rail system,
however, pressure
generation and
injection are separate,
meaning that the
fuel is constantly
available at the
required pressure
for injection.
Broad range of solutions
The common rail system
Common rail systems have a modular design. Each system
consists of a high-pressure pump, injectors, a rail, and an
electronic control unit.
Bosch offers common rail systems for all vehicle
models from microcars to heavy luxury limousines.
The high-pressure pumps operate at pressures between
1,100 and 2,200 bar. Systems with individual pumps are
also available (plug-in pumps). The injectors use either
solenoid valve or Piezo technology.
Mode of operation
With conventional diesel injection systems, the fuel
pressure has to be generated individually for each injection.
With the common rail system, however, pressure generation
and injection are separate, meaning that the fuel is constantly
available at the required pressure for injection. Pressure
generation takes place in the high-pressure pump. The pump
compresses the fuel and feeds it via a high-pressure pipe
to the inlet of the rail, which acts as a shared high-pressure
reservoir for all injectors – hence the name “common rail”.
From there, the fuel is distributed to the individual injectors,
which inject it into the cylinder’s combustion chamber.
| words in action
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Advantages
•
Clean and highly efficient fuel injection due to
extremely short spraying distances and multiple
injection
•
High engine power and smooth running with
low consumption and emissions
•
Can be used with all v ehicle models due to
modular design
may 2014