Diesel - Common Rail

Common Rail Injector

Proprietary technologies in material development and processing enable DENSO’s solenoid injectors to achieve high performance with a fatigue strength sufficient for 1,800 bar injection pressure.

These injectors can inject fuel at an interval of 0.4 milliseconds with only one cubic millimeter per pilot injection. 

The stringent emission controls that vehicle manufacturers now have to meet has resulted in higher injection pressures, around 2000 bar or 29,000psi.
This has resulted in the injector design becoming much more complex, with finer tolerances than previously mechanically operated injectors.

Common Rail Pump

DENSO common rail pumps sends only the required amount of fuel to the common rail through the electromagnetic valve, precisely controlling the fuel pressure in the common rail.

There are three types of DENSO common rail pump:

  • HP-3 - Passenger cars and Light-duty vehicles
  • HP-4 - Medium-duty vehicles
  • HP-0 - Heavy-duty vehicles (available up to 1,600 bar)

The supply pump pressurises fuel up to 1,800 bar and sends it to the common rail. 
The fuel pressure in the common rail is detected by the high-pressure sensor and controlled by adjusting an electromagnetic valve of the supply pump.

The DENSO difference:

  • Generates high fuel pressure up to 1,800 bar
  • Adapting an outer cam structure rather than an inner cam structure reduces the surface pressure applied to the sliding part of the plunger that pressurizes fuel
  • The plunger is made of a newly developed material with very little foreign matter and the sliding part of the plunger is coated with a ceramic material, improving fatigue limit of the plunger
  • Light weight
  • Using aluminum for pump housing parts that are not exposed to high pressure achieves the world’s lightest supply pump for the common rail system
  • Precise control of fuel pressure in the common rail
  • The supply pump sends only a required amount of fuel to the common rail through the electromagnetic valve, precisely controlling the fuel pressure in the common rail