Lucas Diesel Korea offers a wide range of diesel injector nozzles; these fall into two groups:

• Multi-hole type
• Pintle type

• Short stem Multi-hole:
  Traditional nozzle construction. Mainly used with high spring holders.
• Long stem Multi-hole:
  These are used on current engine constructions and allow more flexibility in cylinder head design because of the small tip diameter. Low emission types have been introduced to meet future requirements.
• Valve-Covered Orifce nozzle(VCO):
  This is a version of the low emission long-stem nozzle where the needle valve covers the injection holes when it closes, rapidly stopping the fuel flow. The "sac" in previous designs is also eliminated, so preventing the retention of fuel between the closed needle valve and the injection holes, further reducing exhaust emission.

Pintaux nozzle
This has a small auxiliary hole which produces a high velocity spray at low injection rate to improve cold starting. This nozzle type also reduces engine knock when idling.

The injector is made up of two main parts: a nozzle holder and nozzle.

• Before the injection pump begins fuel delivery, the nozzle valve is closed and held by a spring.
• The injection pump begins its pumping stroke, and fuel enters the injector via an inlet connection, and travels down the fuel passages to the fuel gallery which surrounds the needle valve.
• Fuel pressure rises forcing the needle valve to open at the pre-set pressure.
• Fuel then passes through a small space called the sac to the injection hole or holes.
• The fuel comes out of these holes in the form of a fine spray.
• As pumping pressure falls, the valve spring closes the needle valve and fuel injection is ended
• The valve then forms a seal against combustion pressure to prevent exhaust gas being forced back through the injector and into the fuel line.

The DPA distributor type fuel injection pump, incorporates a sensitive all-speed governor, is a compact, self contained unit for high speed multi-cylinder diesel engines of up 2 liters capacity per cylinder.
It is relatively simple design, and incorporates no ball or roller bearing, gears or highly stressed springs. The number of working parts remains the same irrespective of the number of engine cylinders the pump is required to serve.
The pump is flange mounted to the engine. It is oiltight, and during operation all moving parts are lubricated by fuel oil under pressure, so that no additional lubrication system is required.
Fuel injection is effected by a single element having twin opposed plungers located within a transverse bore in a central rotation member which acts as a distributor. The pump plungers are actuated by lobe on an internal camring. Fuel is accurately metered to the pumping element, and the high pressure charges are distributed to the engine cylinders at the required timing intervals through ports in the rotor and the hydraulic head.
The integral governor is of the mechanical fly-weight type, and gives accurate control of engine speed under all load conditions. Most pumps have an automatic device which varies the point of commencement of injection.
The single pumping element ensures uniform delivery of fuel to each engine cylinder, and eliminates having to balance the deliveries from each of the high-pressure delivery pipes.

The Lucas range of electronic unit injectors(EUI) was developed for direct injection(DI) engines in markets having stringent emissions control. Initial production has been specifically for premium truck applications but versions are also available for mid range DI and high speed direct injection(HSDI) engines used predominantly on the lastest off highway and passenger car applications.
As emission legislation is tightened in response to environmental pressures, the demand for cleaner more economical engines intensifies. The new generation of diesel engines need to have better fuel consumption, lower noise and exhaust emissions than current models. This has created a demand for fuel injection equipment which optimises engine performance and minimises emissions through the use of high injection pressures and electronic control of injection timing and fuelling.

Performance advantages

• Higher injection pressures(up to 2000 bar)
• Fully flexible electronic fuel quantity and timing control.
• Injection rate shaping, using two stage needle lift and pilot injection.
• Control of all engine functions, eg.turbo charger, intercooler, EGR.
• Shot to shot fuel adjustment for effective transient control and improved driveability.
• Cylinder cut-out for idling and low load fuel economy and diagnostecs.
• Communications with other vehicle systems e.g.ABS/ABR, transmission.
• Fuel diagnostics capability.
• Range of control units for on-engine mounting.

• accelerator pedal position
• engine speed
• air inlet manifold temperature
• air inlet manifold pressure
• coolant temperature

To meet the future stringent emissions requirements, and offering further improvements in fuel economy, Lucas Varity has developed a new, high pressure fuel injection system-the Lucas Varity Common Rail system(LVCR)
Fuel injection Equipment with the capability of operating at very high pressure will be required to achieve the ultra low emissions challenges and low noise demands of the coming years, and this latest addition to the Lucas Varity portfolio, the Lucas Varity Common Rail system extends the Lucas fuel injection product range for future High Speed Direct Injection(HSDI) engines.


LVCR ADVANTAGES

• Compact design
  The compact design of the injector outline enables the LVCR system to be used on 2 or 4 valve per cylinder engines.
• Modular system
  With one electronically driven injector per engine cylinder, the system is modular and can be used on 3,4,5 and 6 cylinders.
• Low drive torque
  As the pumping of the pressure rail is not phased with the injection, the Common Rail System requires a low drive torque from the engine.
• Independent injection pressure
  The injection pressure is independent of the engine speed and load, so enabling high injection pressures at low speed if required.
• Lower NOx emissions
  Injection sequences which include preiods both pre and post the main injection can be utiised to reduce emissions particularly NOx. enabling the system to meet the stringent emission levels required by EURO-III and US-98 legislation and beyond.
• Noise reduction & NOx control
  The inclusion of pilot injection results in a significant reduction in engine noise.
• Full electronic control
  Common Rail offers all the benefits of full electronic control for vehicles, including extrernly accurate fuel metering and timing, as well as the option to interface with other vehicle functions.