Control device for continuously variable transmission

摘要

PROBLEM TO BE SOLVED: To suppress damage to a belt of a continuously variable transmission. A device 200 includes rotation speed sensors 25 and 26 for detecting the rotation speeds of input / output shafts of a continuously variable transmission, and a hydraulic control device for adjusting a pinching pressure acting on a belt from a drive / driven pulley. , A controller 28 that controls the hydraulic control device based on the rotation speed of the input / output shaft is provided. The controller 28 includes an evaluation value calculation unit 280 that calculates a slip evaluation value that quantifies the degree of belt slip based on fluctuations in the rotation speed of the input / output shaft, and a belt slip state that moves from an elastic slip state to a moving slip. The critical value calculation unit 281 that calculates the critical value of the slip evaluation value when changing to a state, and the safety factor that calculates the margin (safety factor) of the slip evaluation value with respect to the critical value based on the slip evaluation value and the critical value. It has a calculation unit 282 and an output unit 283 that outputs a control signal to the hydraulic control device based on the safety factor. [Selection diagram] Fig. 4