Analysis of impact and motion of the needle in diesel engine injector

The movement of needle with high intensive load in diesel injector is swift. And the impact between the needle and its seat works in short time and brings very large impact stress, which decides the working reliability of components. In this paper, according to the loading function getting from virtual working process and with finite element method, the nonlinear dynamic analysis of multi-mass movement system in injector, the research of influence factors of the impact between the needle and its seat, simulation of movement of needle assemblies and calculation of impact stress are presented. The movement of needles in multiple injectors and fuel injection pressure are tested on the 190 testing diesel, which validates the effectiveness of the mathematic model and the simulation method in practice. And the result can apply to design and improvement of injectors.