| 摘要 |
PURPOSE:To provide excellent speed control logic by correctly judging whether input torque which is helpful for the speed control of an automatic transmission is positive or negative, that is, a car is running with power-on or with inertia. CONSTITUTION:The output torque T0 of a torque transmitting path including planetary gear sets 10 and 11 is detected by a sensor 62 to judge whether the torque input in a transmission is positive or negative, that is, a car is running with power on or with inertia, based on the polarity of output torque. An automatic transmission changes speed in such logic that firstly the car is allowed to run with a hand brake engaged with a shift lever shifted to the range 2 from the range 1 during running with power on, and when torque phase finishes, a low & reverse brake 13 is disengaged, and the engagement and disengagement of both brakes are done in the reverse order with the shift lever shifted to the range 2 from the range 1 during running with inertia. In both running modes, the transmission can change speed smoothly. |
