INFLUENCE OF STRUCTURAL PARAMETERS OF A COMMON RAIL ELECTROMAGNETIC INJECTOR ON INJECTED FUEL QUANTITY

Abstract

This article investigates the influence of structural parameters of a Common Rail electromagnetic injector on the quantity of injected fuel. The accuracy of diesel fuel injection systems has a direct impact on engine efficiency, combustion stability and exhaust emissions; therefore, changes in injector structural parameters may significantly affect the operation of the entire fuel supply system. The aim of this study was to investigate how variations in injector structural parameters influence the injected fuel quantity under different operating conditions. Experimental investigations were performed using a Common Rail injector testing bench “Open System CR-IP”, which allows measurement of injected fuel quantities at different injector operating modes. During the research, the influence of control valve lift, electromagnetic valve spring preload and injector needle spring preload on fuel dosing characteristics was analysed. Structural parameters were modified by adjusting the thickness of calibration shims in order to simulate possible geometric deviations of injector components that may occur during operation. The results showed that even small changes in structural parameters can cause significant variations in injected fuel quantity under different operating regimes. The study revealed that injector operation is particularly sensitive to variations in control valve lift, which may lead to both an increase in fuel quantity and unstable injector operation or complete interruption of fuel injection. The obtained results confirm that precise adjustment of injector structural parameters is essential to ensure stable fuel injection and reliable operation of diesel engine fuel systems.