PURPOSE: To stabilize the changeover timing of a hydraulic friction element by controlling the quantity of oil to be supplied into a piston cylinder to the maximum value during the detection of a coupling starting point at an engine mount displacement speed, at the time of coupling of a hydraulic friction element.
CONSTITUTION: To a control unit 5, rotation pulses 51-53 of the impeller, turbine, and output shaft of a torque converter 2, a shift range signal 51, a throttle opening degree signal 55, and the mount displacement signal 56 of an engine 1 corresponding to the reaction to the driving of the output shaft 32 of an auxiliary gearbox 3 are inputted, and based on the mount displacement speed value, it detects the coupling starting point of a hydraulic friction element. And, the discharge of the electro-hydraulic conversion value of a hydraulic controller 4 is set to the maximum value until the hydraulic friction element reaches the coupling starting point since the issue of a speed change instruction. In this way, the invalid stroke time of a piston accompanying the coupling operation of the hydraulic friction element is controlled shortest, and changeover timing can be done stably.
HASUNAKA KOUJI
TAKAGI KIYOSHI
