Patent ID: 8924110

Claim:
A control device for a continuously variable transmission, the continuously variable transmission including a primary pulley to which drive force of an internal combustion engine is input, a secondary pulley coupled to a vehicle wheel, and a belt wound upon the pair of pulleys for transmitting the drive force, wherein the control device controls hydraulic pressure to be supplied to each of the pulleys to change a winding radius of the belt in each of the pulleys, and executes feedback control of the hydraulic pressure of the primary pulley based on an actual transmission gear ratio calculated based on a rotational speed of each of the pulleys and a target transmission gear ratio, the control device comprising: a rotational speed sensor for detecting a rotational speed of at least a part of a power transmission system from the internal combustion engine to the wheel, wherein when the rotational speed is less than a first reference value, the control device does not execute the feedback control and executes a lower limit hydraulic control for regulating the hydraulic pressure of the primary pulley to a lower limit hydraulic pressure capable of setting a transmission gear ratio to be a maximum transmission gear ratio, when the rotational speed is equal to or exceeds the first reference value and is less than a second reference value, which is larger than the first reference value, the control device does not execute the feedback control and executes a balanced hydraulic control for regulating the hydraulic pressure of the primary pulley to a minimum hydraulic pressure, which is higher than the lower limit hydraulic pressure and required for maintaining the transmission gear ratio at the maximum transmission gear ratio, and when the rotational speed is equal to or exceeds the second reference value the control device executes the feedback control.