Patent ID: 7356399
Filing Date: 2008-04-08
Classification: F16D,F16H,Y10T

Abstract:
1. A failure determination system for a continuously variable transmission including a drive pulley which has torque input from a drive source of a vehicle, and whose pulley width is reduced by supply of oil pressure, a driven pulley which is connected to the drive pulley via a belt, and whose pulley width is reduced by supply of oil pressure, and a drive-side control valve and a driven-side control valve that control the oil pressure supplied from a hydraulic system to the drive pulley and the driven pulley, respectively, so as to carry out speed varying operation, the failure determination system determining failure of any of the drive-side control valve and the driven-side control valve, the failure determination system comprising: transmission ratio-detecting means for detecting a transmission ratio between the drive pulley and the driven pulley; vehicle speed-detecting means for detecting a vehicle speed of the vehicle; and failure-determining means for determining failure of at least one of the drive-side control valve and the driven-side control valve, based on the transmission ratio detected at one of a time during stoppage of the vehicle and a time immediately before the stoppage of the vehicle, the transmission ratio detected after a restart of the vehicle after the stoppage, and the detected vehicle speed.