Research On Influence Of Temperature During Starting And Shifting Of Dual-clutch Transmission

This paper is funded by Chinese Nature Science Foundation(Project Number:51205432), which according to principle of operation of wet dual clutch automatic transmission, and the feature of clutching procedure of wet dual clutch. We construct transmitted torque model of wet clutch which is considered temperature effect, and we input torque transmission of wet clutch model considered temperature into dynamic model of starting and shifting of wet dual clutch automatic transmission model. Major research contents are as follows:1)Transmitted torque mathematical model of clutching procedure of wet clutch and one-dimensional temperature field are constructed, according to clutching feature of wet clutch, and with the use of Average Reynolds Equation, Rough Surface Flexible Contact Model and Heat Transfer Theory.2)With the use of numerical coupling algorithm, we solve the problem that torque transmission mathematical model of clutching procedure of wet clutch and one-dimensional temperature field. We analyze the temperature feature and transmitted torque of clutching procedure of wet clutch influenced by flow of lubricant oil, modulus of friction elasticity.3)After analyzed dynamic features of starting procedure of wet dual clutch vehicle,we construct starting mathematical model of wet dual clutch vehicle. And also construct simulation model of starting procedure by means of Matlab/Simulink simulation platform.Torque transmission model considered temperature feature is input into dynamic model of starting procedure of wet dual clutch, and we do simulation analyses to starting of single clutch of first gear as well as rotation rate change, work of slipping, sliding friction power and degree of impact of the procedure of united starting of dual clutch.4)After analyzed dynamic features of shifting procedure of wet dual clutch vehicle,we construct shifting mathematical model of wet dual clutch vehicle. And also construct simulation model of shifting procedure by means of Matlab/Simulink simulation platform.Torque transmission model considered temperature feature is input into dynamic model of shifting procedure of wet dual clutch, and we do simulation analyses to starting of single clutch of first gear as well as rotation rate change, work of slipping, sliding friction power and degree of impact of the procedure of shifting with example of first to second gear.5)With initial temperature 40℃, we analyze how flow of lubricant oil and friction flexibility modulus influence starting and shifting feature. We also analyze and compare starting and shifting with the temperature 20℃and 100℃. Result shows that the time of20℃starting and shifting is longer than 100℃starting, while for that degree of comfort, it is against that.