关键词: 车辆工程, 无级变速传动, 夹紧力, 可靠性

Abstract:

From three respects including clamping force computing method, control algorithm development and clamping force reliability validation, several key points of CVT clamping force control process were studied. The obscure concepts of absolute safety factor and relative safety factor were explained. Normal relative safety factor method could not ensure the safety of clamping force. Inertia torque and computing process were analyzed to determine the influence factors of primary pulley torque computing error. The right computing method and process of clamping force target value were presented. Coupling effects between clamping force control and ratio control were studied by experiments. To avoid metal-belt slipping, ratio shift rate had to be limited while the vehicle was in low speed and heavy duty. The most likely condition leading to metal-belt slipping was analyzed. To validate the reliability of control methods, vehicle running process from ice surface to cement road was simulated.

Key words: automotive engineering, continuously variable transmission(CVT), clamping force, reliability