Abstract: Aiming at the problem of adaptability of the pilot solenoid valve of integral electro-hydraulic module in automatic transmission to environment, a thermo-fluid-solid coupling simulation on the main plunger of pilot solenoid valve is performed to contrastively analyze the influence of heat generation of solenoid valve in operation on the deformation of clearance between valve and plunger, and based on which the sticking condition and frictional force of plunger are analyzed. The results show that the thermal deformation of aluminum alloy valve sleeve is relatively significant, resulting in a corresponding increase in the friction force of plunger, and the sticking up of plunger may occur when there are particulate matters with larger size in the fluid, so the strict control of fluid contamination is essential. The analysis results of friction force also provide a basis for the analysis on the dynamic response characteristics of solenoid valves.

Key words: integral electro-hydraulic module, thermo-fluid-solid coupling, friction force of plunger