Steuereinrichtung eines Automatikgetriebes

摘要

An abrupt change in resisting force serving to prevent the vehicle from retreating which is likely to be caused during neutral control carried out concurrently with hill-hold control and thereby to provide the driver with no sense of incompatibility. Control to disengage an input clutch C1 is carried out in order to enhance the fuel efficiency and, at the same time, control to engage a hill-hold brake B1 is carried out for preventing the vehicle from retreating on a steep slope with the vehicle put in a halted state in the forward drive range. At that time, at a step ST6, the hydraulic pressure PC-1 of the input clutch C1 is gradually reduced by PCIR (PC-1 <--- PC-1 - PCIR) while the hydraulic pressure PB-1 of the hill-hold brake B1 is increased gradually so as to satisfy an equation PB-1 = K1 + K2 X e where PCIR is a change in hydraulic pressure which is required for gradually disengaging the first clutch C1 and e is the input/output rotational-speed ratio of a torque converter, a ratio of the rotational speed NC-1 of the first clutch C1 to the rotational speed NE of the engine. In this way, an abrupt change in force resisting the retreat of a vehicle can be eliminated.