CVT Clutch Structure Parameter Optimization And Startup Control Algorithm

The startup control indexes of CVT contradict each other obviously:excessive engagement speed can get rapid startup response and prolong service of clutch, however, it will cause more startup jerk; Inversely, If the engagement speed is excessively reduced for the sake of startup smoothness, then it will increases the friction work at the cost of less steady of transmit and service of clutch.Aiming at these contradictory indexes, in order to ameliorate methods for restricting both jerk and friction work, some accidence study have been done this paper as follow:(1) The synthesis parameter of friction disk abrasion PV has been defined by analysing the factors that affect friction disk abrasion, then the parameter is taken as object function, and restriction condition equations are established as well, afterwards, the main parameters of friction disk are optimized by dint of MATLAB optimization toolbox.(2) The two-dimension finite element model of wet multiple-disk clutches have been established, then the way of fixation, material characteristic and thickness of friction lining affect the distribution of initial joint pressure between friction pairs have been researched.(3) The variable relation between the structure of oil groove section and the convection heat transfer coefficient was researched at synchronization state under the condition of same area of oil groove section. On this basis, the three oil grooves have been ameliorated, thermoplastic contact finite element model for the initial friction pairs and the ameliorated ones are created, After the distribution law of stress and thermal of friction pairs were gained.(4) Both the vehicle startup quality and the process of CVT startup-clutch engagement have been introduced, then different control goal have been set aiming at the stage trait of engagement process; The fuzzy control algorithm has been designed. Then fuzzy input, membership functions and fuzzy rulers are made, the oil pressure control rulers of spare travel stage and slip stage are gained after the experience of proficiency drivers are summarize as inference rulers; The mathematical model of clutch dynamics and hydraulic control system have been built, which are combined with fuzzy control algorithm, then the simulink model of entire vehicle have been built as well. Base on the ameliorated wet clutch, startup simulation have been done in different operation intentions. (5) For validating the the real control effect of fuzzy control algorithm, the entire vehicle have been tested on road by dint of exist CVT test system.