Control method and control apparatus of automatic transmission

A control apparatus for an automatic transmission having an input shaft rotating by torque from a drive power source, an output shaft for outputting a rotation torque to a drive shaft of a vehicle, plural idle gears for transferring the rotation torque between said input shaft and output shaft, and plural synchromeshes that constitute respective gear positions by engaging with each idle gear, furthermore said synchromeshes are equipped with;

• plural hubs rotating integrally with said input shaft or said output shaft;
• plural sleeves respectively provided on said hubs, rotatable integrally with said hubs and movable axially on said hubs;
• and plural rings respectively provided between said hubs and idle gears, and moving any of said sleeves toward the corresponding idle gear, any of said rings is pressed on the idle gear, the rotation torque from said input shaft is transferred to said output shaft through the ring and idle gear by the friction, and the sleeve can move to engage into the idle gear with synchronized speed,
• wherein said control apparatus has a control unit which performs the following contents:
• when shifting the gear position into a target gear position from a current gear position, some gear position different from said current gear position is used as one distributing gear position, said control unit controls the pressing load of a synchromesh of said one distributing gear position to make at least part of the rotation torque from the drive power source transfer by the friction, thereby releases at least part of the rotation torque transferred by a synchromesh of said current gear position, and then moves the synchromesh of said curent gear position to a disengaging position not meshed with said idle gear, thereafter uses another gear position different from said target gear position and said one distributing gear position as another distributing gear position, so that controls the pressing load of the synchromesh of said another distributing gear to make the transfer torque increase gradually by the friction, and
• simultaneously makes the pressing load of the synchromesh of said one distributing gear position decrease gradually, besides such a distribution of transfer torque, makes the speed of said input shaft synchronize with the speed corresponding to said target gear position by controlling the speed of said input shaft, and then moves the synchromesh of the target gear position to the meshing position.