| 摘要 |
PURPOSE:To control the engaging pressure supplied to a friction element in characteristics suitable for the demand at the respective speed change steps and to improve the control accuracy for the engaging pressure in an automatic transmission including a friction element put in the engaging state with a difference in the torque transmission capacity at plural speed change steps. CONSTITUTION:A control device of an automatic transmission comprises a control valve 78 for regulating the engaging pressure supplied to a low reverse brake 29 put in the engaging state at a first speed for an engine brake and at the backward speed and a linear solenoid valve for supplying the control pressure to the control valve 78. Further, there are provided lines 53, 85, 87 for inhibiting the pressure regulating operation of the control valve 78 at the backward speed, and an accumulator 92 to which the operating oil is introduced at the time of switching to the backward step. |
