Patent ID: 6254508
Filing Date: 2001-07-03
Classification: B60W,F16H,Y10T

Abstract:
A speed-change control apparatus for an automatic transmission, comprising:a transmission input shaft which receives power from an engine output shaft;a transmission output shaft coupled to wheels;a plurality of frictional engagement elements for changing between different power transmission paths between the transmission input and output shafts;hydraulic servos for operatively engaging and releasing the frictional engagement elements;hydraulic pressure control means for controlling hydraulic pressures applied to the hydraulic servos;engine control means for controlling an output torque of the engine, including torque-down control to reduce engine torque;a controller for receiving signals from respective sensors which detect various vehicle running conditions and for outputting signals to the hydraulic pressure control means and the engine control means;multiple speed-change determination means for determining a multiple speed-change operation when, during one of an up-shift speed-change operation and a down-shift speed-change operation, a command to perform the other speed-change operation has been issued;hydraulic pressure command means for switching from a first hydraulic pressure command for performing said one speed-change operation to a second hydraulic pressure command for performing the other of the speed-change operations, and for outputting the second hydraulic pressure command to the hydraulic pressure control responsive to determination of the multiple speed-change operation;speed-change start determination means for detecting that said one speed-change operation has been switched to the other speed change operation by the hydraulic pressure control performed by the hydraulic pressure control means responsive to the switch of hydraulic pressure commands, and for determining that the other speed-change operation has actually started; andengine torque change means for issuing a command to change a torque-down control by the engine control means responsive to a determination that the other speed-change operation has started.