Patent ID: 8096906

Claim:
A continuously variable transmission comprising: an input side primary pulley which varies a groove width according to a first oil pressure; an output side secondary pulley which varies a groove width according to a second oil pressure; a belt looped around the primary pulley and the secondary pulley, having a contact radius with the pulleys which varies in accordance with the groove width; an oil pump driven by an engine; a first sensor which detects a rotation speed of the primary pulley; a second sensor which detects the second oil pressure; and a controller, which: determines a rapid deceleration state of a vehicle; calculates a lower limit secondary pulley pressure at which slippage occurs in the belt on the primary pulley side on the basis of the rotation speed of the primary pulley; determines that slippage is about to occur in the belt on the primary pulley side when the vehicle is determined to be in a state of rapid deceleration and the second oil pressure which is detected by the second sensor is lower than the lower limit secondary pulley pressure; and prevents a reduction in the first oil pressure, having determined that slippage is about to occur in the belt.