System for estimating temperature of vehicle hydraulically-operated transmission

摘要

A system for estimating a temperature of a vehicle hydraulically-operated transmission (T) including a hydraulic torque converter (2), a plurality of frictional engaging elements (C1,C2,C3,C4R) such as clutches installed in the transmission and a hydraulic pressure supplying circuit (O) for discharging hydraulic fluid from one of said plurality of frictional engaging elements and for supplying hydraulic fluid to another to bring said one and another one of said plurality of frictional engaging elements into operation such that gear-shift is effected in the transmission. A heat quantity generated by the hydraulic coupling means ( DELTA Ttr), a heat quantity generated by at least one of the frictional engaging elements at gear-shift ( DELTA Tcl(No)), a heat quantity generated by stirring of the hydraulic fluid ( DELTA Tst), a heat quantity generated or absorbed at a heat exchanger which exchanges heat from the fluid ( DELTA Tra), and some similar values are calculated and summed to estimate a temperature of the clutches, thereby enabling a fine hydraulic pressure control.