Patent ID: 6443871
Filing Date: 2002-09-03
Classification: F16H,Y10S,Y10T

Abstract:
An apparatus for controlling a belt-type continuously variable transmission of a motor vehicle that is provided in a power transmission path, the transmission having an input shaft disposed on a power source side of the transmission, an output shaft disposed on a side of the transmission opposite from the power source side, a pair of pulleys mounted on the input shaft and the output shaft, respectively, and a torque transfer belt that is wound around the pulleys to effect power transmission by use of frictional force, the transmission having a continuously variable speed ratio, which is a ratio of a rotation speed of the input shaft to a rotation speed of the output shaft, the apparatus comprising a controller that:controls the speed ratio of the continuously variable transmission by changing a groove width of each of the pulleys; controls a belt clamping pressure applied to at least one of the pulleys to clamp the torque transfer belt; and sets the speed ratio of the continuously variable transmission to a low-load speed ratio when it is determined that control of the belt clamping pressure has failed and the belt clamping pressure is raised to a high level, the low-load speed ratio being predetermined so that a load that is applied to the torque transfer belt is substantially minimized.