| 摘要 |
PURPOSE:To reduce the speed change shock when a speed increasing side rotary member and the output shaft side are completely connected in shift down by calculating the starting time of hydraulic pressure supply to a connection side element based on a specific operation parameter and connecting and actuating the connection side element based on the calculation result. CONSTITUTION:The auxiliary transmission 2 of an automatic transmission 1 is provided with a turbine rotary shaft 4 integrated with the turbine blade 8 of a torque converter 3 at the center and planetary gear trains and speed change elements(a brake B and clutch C) around the shaft 4. The auxiliary transmission 2 is connected to a connection side element to actuate it, establishing an objective speed change step calculated according to the car speed and load information of a vehicle. In this case, during down shifting controlling, based on the time required for play stopping of the actuator of the connection side element, the rotation speed of a speed increasing side rotary member, objective rotation speed to be attained in the completion of the speed change of the speed increase side rotary member, and the current rotation speed changing ratio during speed changing, the starting time of the hydraulic pressure supply to the connection side element is calculated and controlled. |
