Launching Performance Analysis of a Continuously Variable Transmission Vehicle With Different Torsional Couplings

This article describes the launching behaviors of passenger cars equipped with continuously variable transmission (CVT), which have different torsional couplings: a torsion damper and a dual mass flywheel. To reduce the driveline vibration and noise, a torsional coupling is installed in the CVT vehicle, in which the wet type multiplate clutch is used as a start device. In addition, a torsional coupling makes considerable effects on the launching performance of a vehicle. The launching performances, considered here, are the acceleration performance with various throttle positions and the transient characteristics of vehicle creep and throttle tip-in. By using the mathematical models of each driveline component, we developed a simulation program to investigate the launching performance in various launching conditions. In order to verify our simulation program, we performed the road test of a prototype vehicle that has torsion damper as a torsional coupling. Finally, we analyzed and compared the launching performances in two cases of a torsion damper and a dual mass flywheel using the developed simulation program.