Control device for continuously variable transmission

A control device for a continuously variable transmission mounted in a vehicle, the continuously variable transmission having an input side primary pulley inputting power from an engine, an output side secondary pulley and a power transmission member wound around these pulleys, the device comprising:

• a secondary pressure control unit configured to set a secondary pressure target value that is a target value of a secondary pressure supplied to the secondary pulley on the basis of a required torque transmission capacity and to control the secondary pressure according to the secondary pressure target value;
• a primary pressure control unit configured to set a primary pressure target value that is a target value of a primary pressure supplied to the primary pulley on the basis of a target transmission ratio and to control the primary pressure according to the primary pressure target value;
• and
• a line pressure control unit configured to set, as a line pressure target value that is a target value of a line pressure, greater one of a secondary pressure comparison reference value corresponding to the secondary pressure target value and a primary pressure comparison reference value corresponding to the primary pressure target value and to control the line pressure according to the line pressure target value, and
• the line pressure control unit configured to set, at a vehicle constant speed travel control, the line pressure target value with a value obtained by adding a first offset amount to the secondary pressure target value being the secondary pressure comparison reference value and a value obtained by adding a second offset amount to the primary pressure target value being the primary pressure comparison reference value, and
• except when executing the vehicle constant speed travel control, at least one of the secondary pressure comparison reference value and the primary pressure comparison reference value being set to be smaller than a value when executing the constant speed travel control.