Design, modeling, and analysis of giant magnetostrictive injector

In view of the shortcomings of the traditional high-pressure common rail electronically controlled injector in needle valve driving mode and driving components, a direct-drive type giant magnetostrictive injector (GMI) is designed. Based on the working principle of the GMI, the magnetic field model, hysteresis nonlinear model, and magnetostrictive model are established. The magnetic field model and hysteresis nonlinear model are simulated and analyzed, and the GMA magnetostrictive model is solved numerically and verified experimentally. Finally, COMSOL Multiphysics software is used to conduct electro-magnetic-mechanical coupling simulation analysis on the whole GMI output model, and the relationship between the needle valve lift of the injector and the output displacement of the actuator was obtained. The research results show that the displacement curve calculated using the GMA magnetostrictive model is basically consistent with the displacement curve measured by experiment, which proves that the established model can reflect the actual situation and verify the correctness of the model. The magnitude and direction of the GMI needle valve lift are determined by the magnitude and direction of GMA output displacement. The two directions are opposite, and the size ratio is 4, so when the current is 6 A, the GMA output displacement is 0.12 mm, and the needle valve lift is 0.48 mm, which meets the requirements of the injector needle valve lift, verifies the feasibility of GMI structure design, and has good theoretical and practical guiding values.