The double-stage nozzle with pressure controlled injection rate control together with the high injection pressure are an important factor for good combustion properties in the entire engine map area of DI high speed Diesel Engines.
With the described design a combination of tangential and rectangular deflection of the fuel at the beginning of injection and before entering the nozzle holes is achieved, thus reducing the rate of injection and the penetration of the fuel prior to combustion. The atomization of the fuel during the ignition delay period is also increased. The combination of these properties reduces the ignition delay emissions and combustion noise. After the start of combustion, the nozzle needle opens the fuel orifices completely and the high pressure sprays inject the fuel directly into the already existing flame. The double guided nozzle needle assures the reproducibility and durability of the said system. The accurate calibration and simple maintenance are incorporated in the described equipment. All electronic and electric components are placed outside of the engine and are not exposed to the hot engine oil. The electronic system controls the amount of injected fuel and injection timing. An accurate feed back signal for the amount of injected fuel and injection timing is incorporated in the system.