The range of Bosch nozzles is diverse and covers all conventional applications. It is based on the unrivaled, extensive expertise of Bosch as a vital partner for international vehicle manufacturers.
The unit injector system is an electronically controlled system developed by Bosch for diesel direct injection. It is suitable for cars and light commercial vehicles with up to 5 l engine capacity and 312 hp engine power, the first installation in series production cars was 1998.
The special feature of the unit injector system is that an individual pump is assigned to each cylinder. The pump and nozzle are therefore combined in a compact assembly which is installed directly in the cylinder head. The unit injector system enables high injection pressures up to 2,200 bar.
Bosch 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. 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.
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.
Broad range of solutions
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.