CONTROLLER AND CONTROL METHOD OF BELT TYPE CONTINUOUSLY VARIABLE TRANSMISSION

摘要

Provided is control device and method for a belt type continuously variable transmission which can reduce drive energy consumption by a decrease in belt friction when the estimated accuracy of belt slip condition is high and which can prevent the belt from greatly slipping during belt slip control when the estimated accuracy of belt slip condition is low. The device includes a primary pulley (42), a secondary pulley (43), and a belt (44) and controls gear ratio based on the running radius of the belt (44) on the pulley by controlling the primary oil pressure and the secondary oil pressure. A belt type continuously variable transmission (4) comprises a belt slip control means (step S3) for performing such control as to oscillate the secondary oil pressure, estimate the belt slip condition by monitoring the phase difference between an oscillation component included in the actual secondary oil pressure and an oscillation component included in the actual gear ratio, and then reduce the actual secondary oil pressure to maintain a predetermined belt slip condition, and a belt slip control permission determining means (step S2) for permitting belt slip control when a torque change speed input to the belt type continuously transmission mechanism (4) is less than a predetermined value.