Study On Temperature Rise During The Engagement Process Of Dry Dual Clutch Friction Pairs

The dry dual clutch transmission has been widely used in medium and small passenger cars due to its good fuel economy and low manufacturing cost.However,because of its small heat capacity and poor heat dissipation conditions,especially in the congested city,the temperature of clutch friction pair increases quickly due to repeated engagement,resulting in the change of the working characteristics of the clutch and the increase of wear,which affects the control precision and service life of dry dual clutch transmission.Therefore,it is important to study the temperature rise during the engagement process.This paper is carried out mainly from the following aspects:(1)The engagement characteristic of clutch is analyzed,and the transmission torque of clutch is determined.On this basis,the dynamic model of dual clutch automatic transmission is established.The dynamic simulation for three kinds of throttle opening conditions is carried out,at the same time,the calculation results also provide the basis for the determination of the boundary conditions needed for temperature rise calculation.(2)Based on the basic theory of heat transfer,the finite element model of dry double clutch is established,the boundary conditions of thermal analysis of friction pairs are determined by the calculation results,the temperature rise of dry dual clutch friction pair under different working conditions is simulated by finite element software,meanwhile,based on the simulation results of the temperature rise,the stress and deformation of the pressure plate and the friction plate are calculated and analyzed.(3)From the point of view of dual clutch control strategy and structure design,the method to optimize the temperature rise of clutch is analyzed.Moreover,combined with the analysis of the reasons for the higher temperature rise of clutch 2,the corresponding optimization scheme is put forward.On the one hand,the control of the engine speed during the engagement process of clutch 2 is raised;on the other hand,the influence of clutch parameters on the temperature rise is analyzed by orthogonal test.The results show that the optimized temperature rise of the clutch 2 is effectively reduced,which provides a theoretical basis for the development of the dry dual clutch.