Patent ID: 8133140

Claim:
A control apparatus for an automatic transmission of a vehicle, the control apparatus comprising: a primary pulley including a movable pulley, the primary pulley being connected with an input; a secondary pulley including a movable pulley, the secondary pulley being connected with an output; a belt wound around the primary pulley and the secondary pulley; a shift control valve configured to regulate a hydraulic pressure of a hydraulic fluid which varies a groove width of the movable pulley of the primary pulley, and to control a target pulley ratio between the primary pulley and the secondary pulley; a secondary pressure regulating valve configured to regulate a secondary pressure of a hydraulic fluid which varies a groove width of the movable pulley of the secondary pulley, and to regulate an engagement pressure between the belt and each of the primary pulley and the secondary pulley; an orifice disposed in an oil passage which is located between the movable pulley of the secondary pulley and the secondary pressure regulating valve, wherein the oil passage is connected to a feedback hydraulic passage, wherein the orifice is arranged to restrict a flow of the hydraulic fluid between the movable pulley of the secondary pulley and the secondary pressure regulation valve; a hydraulic pressure sensor disposed between the secondary pressure regulating valve and the orifice disposed in the oil passage, and configured to sense the secondary pressure; and a control section including a target secondary pressure setting section configured to set a target secondary pressure within a strength limit of the belt so as to prevent a slippage between the belt and each of the primary pulley and the secondary pulley, and an operation switching section configured to switch a shift operation from a normal speed to a high speed higher than the normal speed when a predetermined condition is satisfied, the control section being configured to control the secondary pressure regulating valve by a feedback control based on the target secondary pressure and the secondary pressure sensed by the hydraulic pressure sensor, wherein the target secondary pressure setting section is configured to modify the target secondary pressure by adding a predetermined quantity when a correction initiation condition is satisfied, the correction initiation condition including a first condition that the shift operation is performed at a high speed by switching of the operation switching section.