Diesel Injector

Diesel Injector

Nozzles are used to atomize the fuel with precision and to distribute it in the combustion chamber so that optimal combustion can occur. At the same time, the nozzle reliably seals off the fuel system from the combustion chamber.

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.

Technical features

• The clearance of moving parts stands at 0.002 mm.
• The fuel is injected into the combustion chamber with a pressure of up to 2,000 bar.
• The injected fuel quantity varies between 1 mm³ and 350 mm³ (this quantity is forced through a 0.25 mm² opening at 2,000 km/h).
• Fuel injection is much faster than the blink of an eye.

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.

Technical characteristics

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.

Advantages

• High performance for clean and powerful engines
• High engine power balanced against low consumption and low engine emissions
• High degree of efficiency due to compact design
• Low noise level due to direct assembly in the engine block
• Injection pressures up to 2,200 bar for the ideal combination of air-fuel mixture

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.

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 vehicle models due to modular design