Arrow
Arrow
Slider

Diesel Works services the following common rail injection systems :

Bosch

Denso

Delphi

Siemens / Continental

Caterpillar

Cummins

John Deere

L'Orange

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.

Mode of operation

With conventional diesel injection systems, the fuel pressure has to be generated individually for each injection. With 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 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 pressues 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 and emissions.
  •   Can be used with all vehicle models due to modular design.

A full range of spares are available for repair and we ensure that the injectors are just as good as new before it leaves our workshop.We use the Bosch CRR 3rd stage repair kit to recondition injectors in the same way it is performed in the factory in Germany. By using the CRR kit we can work down to a tolerance of 0.001mm, one thousandth of a millimeter or one micron.

The CRR measures shim thickness, injector body variation and spring tension, it inputs these values into complex equations and gives direction as to what different shim sizes are fitted to the injector to return the fuel delivery back to factory specification.

The injectors are assembled with a special electronic torque wrench that measures both tightening torque and the angle traveled. The tigtening torque and angle must coincide to a  precise specification in order to proceed with assembly.

Post assembly the injectors are tested on our common rail test bench. The Bosch EPS708

eps708

 The EPS708 is our state of the art common rail test bench that provides the functionality for all common rail systems on the market to date

 

Bosch launched the first common rail system in 1997. the system is named after 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 seperate, meaning that the fuel is constantly available at the required pressure for injection. 

We at Diesel Works offer quality repairs  to the common rail system in a financially efficient method. the work we perform carries a 1 year warranty which is the same as if you were to purchase a new injector from the agents, however the cost of a repair usually comes in at a fraction of the cost to replace maling it an attractive option.

Common Rail System for Commercial Vehicles

The Common Rail System is an accumulator injection system. The decisive difference to all other forms of injection system lies in the fact that the pressurization and injection processes are completely independent of each other. The Common Rail System's strategy affords enhanced flexibility for adapting injection processes to reflect the demands of each specific application. It serves as the basis for developing extremely smooth and economical engines offering impressive levels of dynamic response.

The CRS consists of:

  •     High pressure Pump
  •     High-pressure accumulator (rail)
  •     Electronic Control Unit
  •     Injector

Types

The Common Rail System (CRS) is an accumulator-type injection system. In contrast to other injection systems though, high-pressure generation and fuel injection are completely independent of each other. The Common Rail System therefore provides more freedom in the adaptation of the injection process. This makes it possible to develop quiet-running, economic engines featuring outstanding dynamic response.

Injectors

The injectors are installed in the engine's cylinder head, and have the same function as nozzles and nozzle holders on the previous injection systems. The main injector components are:

  •   Hole-type nozzle
  •   Hydraulic servo-system
  •   Solenoid valve

Injector functions

The forces required to open and close the nozzle needle cannot be generated by the solenoid valve on its own. The nozzle needle is therefore indirectly triggered via a hydraulic force-amplification system.

With the solenoid valve closed, the complete chamber volume and the rail are at the same pressure. The nozzle needle is forced against its seat by a spring.

When the solenoid valve opens, fuel flows from the valve control cavity and into the fuel return. The feed throttle prevents complete pressure equalization, and the pressure in the cavity drops. The excess pressure in the chamber volume overcomes the spring force and lifts the needle so that injection can start.

The solenoid valve is no longer energized and closes the opening to the fuel return. The force applied to the control plunger increases along with the increasing pressure in the valve control cavity. The needle closes and injection stops.

Common Rail System (CRS) for passenger cars

Applications: Passenger cars, light-duty commercial vehicles
Power output: 30 kW/cylinder
No. of cylinders: 3...8
Control: Electronic, electrical, solenoid valve, or piezo actors
Injection pressure: 1350 bar (1st gen.), 1600 bar (2nd gen.), 1800 bar (3rd generation with piezo injectors)
Injected fuel quantity: up to 90 mm3 per stroke 

  

Injectors

injectorr

The injectors are installed in the engine's cylinder head, and have the same function as nozzles and nozzle holders on the previous injection systems. The main injector components are:
Hole-type nozzle, hydraulic servo-system, solenoid valve or actuator.


Injector functions


The forces required to open and close the nozzle needle cannot be generated by the solenoid valve on its own. The nozzle needle is therefore indirectly triggered via a hydraulic force-amplification system.
With the solenoid valve closed, the complete chamber volume and the rail are at the same pressure. The nozzle needle is forced against its seat by a spring.

When the solenoid valve opens, fuel flows from the valve control cavity and into the fuel return.The feed throttle prevents complete pressure equalization, and the pressure in the cavity drops. The excess pressure in the chamber volume overcomes the spring force and lifts the needle so that injection can start.

The solenoid valve is no longer energized and closes the opening to the fuel return. The force applied to the control plunger increases along with the increasing pressure in the valve control cavity. The needle closes and injection stops.