Research For Electro-hydraulic System Of New 8-speed Dual-Clutch Transmission

Based on the new 8-speed dual-clutch automatic transmission developed by Automotive Engineering Technology Research Institute of Hefei University of Technology,this dissertation researchs and analyzes the hydraulic system,which is based on theoretical calculation,computer software modeling and simulation,experiment and so on.The main research contents are as follows:(1)The structural characteristics and working principle of the mechanical transmission system of the new 8-speed Dual-Clutch Transmission are analyzed,and the power transmission route of each gear and electronic control unit are analyzed.Based on this,hydraulic system is designed.(2)The structure of the high speed on-off solenoid valve and the internal working principle is analyzed.The high speed on-off solenoid valve is divided into electric field part,magnetic field part,mechanical part and fluid part.The coupling relationship between these four parts is analyzed.The corresponding mathematical model is established and simulated with Matlab/Simulink software simulation model and AMESim software simulation model.Proportional control characteristics of high speed on off valve under PWM signal is analyzed,The influence of the key parameters of the solenoid valve on the effective displacement of the spool and the effective duty cycle is analyzed,a method for improving the control precision of the high speed on off valve by improving the low level voltage Umin of the input signal is proposed.(3)The electric pump source module is designed,the independent function module and the whole system are modeled and simulated based on AMESim software,The influence of multiple functional modules on each other and their effects on the overall performance of the system are analyzed.When the accumulator is used as an auxiliary hydraulic source,the effect of the interaction between the different modules is analyzed.The parameters of the electric pump and the accumulator are optimized.(4)This dissertation analyzes the structural characteristics and working principle of the normally open solenoid valve in the synchronizer control module.The Ansoft Maxwell software is used to model the electromagnet,and then the AMESim simulation software is used to model the normally open solenoid valve,the selector valve spool,the synchronizer hydraulic cylinder,the model is simulated and analyzed.Finally,the diameter of the orifice is designed with the help of the simulation data.(5)The new 8-speed dual-clutch automatic transmission integrated electro-hydraulic system is designed,processed and assembled.Hydraulic system module test plan is formulated,each module is tested,collected and organized experimental data,the test results are analyzed.