The storage supply systems of Common Rail type are characterized by high possibilities in shaping the rate of injection. The possibility to implement multi-injection at high pressure, easiness of adapting the system to the engine, relatively easiness of compensation the arrangement of injector parameters resulting from work tolerance, as well as easiness of making changes in the electronic engine controller enabling the production of engines with various performances, cause that type of these solutions currently are widely used injection systems in diesel engines. Injection system should be characterized above all by high precision fuel dosing into engine cylinders, the accuracy in starts controlling of individual phase of injection, repeatability and reliability and durability, as well as the up keep of these parameters for long time during operating duration. Fuel injection system works in difficult conditions resulting from high pressure, vibrations, electromagnetic interference affecting electronic executive systems and high temperatures. Especially the injector and injection pipes are open to high temperatures. The dimensions of used elements are also important. The article presents selected results concerning the effect of the length of high-pressure pipes on injection process parameters such as fuel amount, overflow in injector, and the fuel pressure course in injection pipe in front of electromagnetic injector socket. The study was conducted with test stand with electronic measurement system of fuel amount. The tests were made at different pressures in the rail and for different durations of the injector opening.
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Rozwój silników wysokoprężnych z bezpośrednim wtryskiem paliwa, wyposażonych w zasobnikowe, elektronicznie sterowane układy zasilania typu Common Rail, jest podyktowany głównie względami ekologicznymi. Duża elastyczność sterowania umożliwiająca realizację wtrysku wielofazowego w szerokim zakresie, możliwość precyzyjnego dawkowania paliwa w odpowiednim momencie, dobre rozpylenie paliwa ze względu na wysokie ciśnienia i łatwość adaptacji do silnika są głównymi przyczynami rozpowszechnienia się silników z tego typu układami zasilania. W artykule przedstawiono wybrane problemy związane ze sterowaniem takim układem, wynikające ze zjawisk falowych w układzie, zmianami właściwości paliwa na skutek podgrzewania się paliwa, zmianami napięcia w instalacji pojazdu, jak również stabilnością sygnału sterującego wtryskiwaczem.
EN
The development of direct fuel injection diesel engines, which are equipped with the electronically controlled systems of Common Rail type, is dictated essentially by the environmental demands. A high control flexibility that allows performing the multi-injection strategy in a wide range, a high precision in fuel injection metering and injection timing, a good fuel spray atomization due to the high injection pressure, and easy adaptation to the existing engines - these are the main factors causing this type of the engine fuel supply systems widely spread. The article presents some problems with controlling such a system derived from the wave phenomena in the system, changes of the fuel properties due to heat release in the fuel injection system, changes in voltage in the vehicle electrical system, as well as stability of the injector control signal.