Patent ID: 9611934
Date: 2017-04-04
CPC Classifications: F16H

Claim:
1. A shift control apparatus for an automatic transmission, the apparatus comprising: a first input shaft, a second input shaft, and an output shaft disposed parallel to each other; a first clutch and a second clutch capable of transmitting a driving force of a drive source to the first input shaft and the second input shaft, respectively; and a plurality of gear trains capable of establishing a plurality of shift stages through a selecting operation of a plurality of synchronizing devices between the first and second input shafts and the output shaft, wherein when a predetermined current shift stage is established between the output shaft and one input shaft of the first and second input shafts, the one input shaft being the first or second input shaft to which the driving force is transmitted by engagement of one clutch of the first and second clutches, and then a target shift stage different from the current shift stage and at which the one clutch is engaged is estimated on a basis of driving conditions of a vehicle and a driver's intention, a predetermined one of the synchronizing devices is engaged to perform a pre-shift operation which allows standby in a state where the output shaft and the other input shaft of the first and second input shafts, the other input shaft being the first or second input shaft to which the driving force is not currently transmitted, are connected by a gear train for the standby shift stage different from the current shift stage and the target shift stage; and when the standby shift stage does not lie between the current shift stage and the target shift stage, the one clutch is disengaged and the other clutch of the first and second clutches is engaged while slipping, and during the disengagement of the one clutch, a synchronizing device for the current shift stage is disengaged and a synchronizing device for the target shift stage is engaged, and then the other clutch is disengaged and the one clutch is engaged.