Method of transmission control for belt-type stepless transmission device

摘要

Drive and driven pulley necessary axial thrusts ( Qdrnec, Qdnnec ) necessary for power transmission without belt slippage are found in accordance with the input torque and transmission ratio; the vehicle speed and degree of accelerator opening target transmission ratio ( itgt ) and target rate of change of transmission ratio ( ditgt ) are found; this axial thrust ( Qdnnec ) is set as the driven pulley target axial thrust ( Qdncmd ); and the drive pulley axial thrust necessary to obtain the target values ( itgt ) and ( ditgt ) is set as the drive pulley target axial thrust ( Qdrcmd ). Then, if ( Qdrcmd ) < ( Qdrnec ), this axial thrust ( Qdrnec ) is altered and set as the drive pulley target axial thrust ( Qdrcmd ) and the driven axial thrust necessary for obtaining the target values ( itgt ), ( ditgt ) is altered and set as the driven pulley target axial thrust ( Qdncmd ). Drive and driven pulley axial thrust control is performed such that these target axial thrusts ( Qdrcmd, Qdncmd ) are obtained.