Research On Dynamic Characteristics Of Dry DCT During The Shift Process

DCT has many similarities in character with MT technology,especially for the Chinese automobile and auto parts enterprises to use existing resources for development.DCT has gradually become the mainstream of the future technology.But in recent years,it has been exposed to excessive temperature rise and low-grade shift shock and other issues frequently.This paper studies DCT in the process of shifting power flow and vehicle dynamics changes.Through friction experiment and analysis of the experimental data,obtained the influence of different pressure and rotational speed on friction coefficient for a type clutch friction plate.The results provide the basis for the clutch pressure control in the process of shifting,also formed the basis of the vehicle shift model.Summarize the characteristics of closed power and the conditions of closed power formed in traditional mechanical structure.Using the closed power theory to the dual clutch automatic transmission shift process,get the conditions of closed power formed in the process of shifting,as well as the negative impact of closed power on the shift process,and the computational expressions of closed power is presented.Using the dual clutch automatic transmission shift principle experiments verify the conclusion of theoretical analysis.Through analysis of the structure and principle of double clutch automatic transmission shifting,the vehicle dynamics model of shift process is established,on the other hand,engine model and clutch friction torque model also been established.Using Matlab/Simulink software build shifting simulation model,and the changing of vehicle speed and acceleration in shift process obtained by simulation,and the closed power and the coefficient of friction on the vehicle dynamic performance also been get.By changing the out-of-gear clutch release time and the in-gear clutch pressure change law to improve the shifting control strategy.The improved control strategy have greatly reduced shift shock obviously without increasing sliding friction work and shift time.So the strategy improved the performance of shift process.