Study On The Characteristic Of Starting-Clutch For CVT

Focusing on the multiplate wet clutch of Continuously Variable Transmission, this essay studies the structure and operation principles, states three commonly used control methods of starting-clutch, analyzes the engaging-process of CVT. After the analysis, some influencing factor are given, the influencing factor is throttle opening, throttle opening rate of change, engine speed, transmission ratio, vehicle load etc. The factors have a great influence on the engaging-process of multiplate wet clutch. This essay will also study the performance evaluation criteria of multiplate wet clutch, after the reasoning of engagement judder and friction work, it is appropriate to make the torque multiplate wet clutch transferred during the engagement as a target of control strategy.A brief introduction of20-Sim software and band graph theory will be presented. Basing on multiplate wet clutch’s given physical model and20-Sim software, a band graph model of the engaging process will come into being. On the basis of20-Sim software, the band graph model will be simulated. I will present the method that changing band graph model into block diagram model and reason the mathematic model of multiplate wet clutch’s engaging-process. In order to contrast the process of establishing model, the block diagram model of multiplate wet clutch will be changed from band graph model and the engaging process’s mathematic model will be obtained. Basing on the Matlab/Simulink software, multiplate wet clutch’s control model will be established eventually. Then I will compare the process of establishing model between20-Sim and Matlab/Simulink.It conducts an analysis of multiplate wet clutch’s transmission torque, presents factors affecting torque during engaging process, selects friction factor model, analyzes the affection of μsO and ks on multiplate wet clutch’s dynamic character during the engaging-process, and clarifies the relationship between high-speed on-off valve and oil pressure, It is easy to control the oil pressure through controlling the frequency of high-speed on-off valves, so the clamping force of multiplate wet clutch could be in control. The frequency of high-speed on-off valves has big influence on engagement of multiplate wet clutch. The torque of engine and vehicle affect the time of multiplate wet clutch’s engaging-process. The analysis of every influencing factor is meaningful for choosing the correct value of influencing factors.