| 摘要 |
PURPOSE:To shorten the invalid stroke time of piston and stabilize the changeover timing of a hydraulic friction element by setting the discharge amount of an electric/hydraulic converting valve to the max. value during the period since a shift command is given until the friction element attains the coupling start point. CONSTITUTION:In No.1 gear position a rear clutch C2 is coupled with a low reverse brake B1. In shifting from No.1 to No.2 position for ex. in case the engine is on the driving side, changing-over of a friction element is made smoothly by performing coupling of a second brake B2 while the low reverse brake B1 is disengaged from No.1 position, and the braking pressure is controlled so as to attain the second position while torque variation on the output shaft is suppressed. Because the piston cylinder of the second brake B2 is filled with oil while the discharge amount of valve is set to the maximum, the duty ratio of duty solenoid valve 44 is made 100% for placing the output. |
