STEUERSYSTEM FUER DIREKTKUPPLUNGEN IN MOMENTWANDLERN VON AUTOMATISCHEN GETRIEBEN FUER FAHRZEUGE

摘要

A direct-coupling control system for torque converter in automatic transmission, comprising a fluid torque converter coupled in series to an auxiliary transmission capable of selectively switching a speed ratio over to one of a plurality of different stages and a direct-coupling mechanism capable of directly mechanically coupling together input and output members of the torque converter using the engaging capacity determined by the function of difference between the actuating pressure acting on the engaging side of the torque converter and the internal pressure acting on the release side thereof. The control system is also provided with a switch valve for allowing the actuating oil to escape to an oil tank synchronously with the speed change operation, and a supplementary mechanism for performing a switching operation so as to raise the internal pressure of the torque converter synchronously with the speed change operation. There is further provided with a supplementary oil passage for supplementing pressurized oil to the torque converter and a switch device for allowing the actuating oil to escape to the oil tank and opening the supplementary oil passage when the throttle opening is at an idle position.