Research On The Effect Of Torque Transfer Characteristics On Shift Performance Of Wet Dual Clutch

With rapidly developing of the automotive industry,vehicle performance and the degree of electronics,more higher automotive quality is constantly pursued by people.As an effective means to improve the power,fuel economy and driving comfort of the vehicle,making a better vehicle starting control and shifting strategy has become the focus of the experts and scholars in the industry.The clutch torque transfer model,as the basis of control strategy's research,whether can accurately reflect the torque of the vehicle clutch or not,will directly affect the effectiveness of control strategy.Therefore,the importance of having a more precise clutch torque transfer model is increasingly prominent.The torque transmitted by wet clutch consists of two parts:asperity torque and hydrodynamic torque.In the previous study of starting control and shift strategy,researchers usually think that the influence of the hydrodynamic torque is much smaller than the asperity torque,so the hydrodynamic torque expression can be simplified and even negligible in a specific study.The purpose of this study is to build a torque transfer model of wet clutch and explore the effect of hydrodynamic torque on the shift quality of the whole vehicle model.In this study,by collecting and integrating the previous research achievements on constructing wet clutch torque transfer model,the further refined,perfected and Matlab/Simulink based torque transmission model of wet clutch is established.By changing the temperature and other parameters,the response of torque transmission characteristics to different factors is observed and studied.Then use the set up clutch module and the corresponding module in SimDriveline to built the whole vehicle model,which consists of the engine module,the transmission module,the transmission control module and the vehicle body module.By comparing the shift quality of the vehicle models considering with non-considering the hydrodynamic torque under the same condition,to figure out whether the hydrodynamic torque has the effect on vehicle shift quality,and by comparing the shift quality of vehicle models at different temperatures,to find out how the hydrodynamic torque effect on vehicle shift quality.Through the comparison and analysis of the simulation results,it can be concluded that the hydrodynamic torque has a great influence on vehicle shift quality,and the influence will change with the temperature.Therefore,A model which can more accurately express the wet clutch torque transfer characteristics should be used,in order to further optimize the vehicle shifting quality in the future.Meanwhile,the starting control and shift strategy of the vehicle should be designed for the change of the hydrodynamic torque correspondingly.