| 摘要 |
PURPOSE:To prevent shift shock by disengaging one of the friction engaging elements, and raising the duty ratio of the other, i.e., a solenoid valve, when the input shaft of an automatic transmission, in the case of power-on down-shift, exceeds the difference of the product of the number of output shaft revolutions and the Low side gear ratio from the amount of rise delay. CONSTITUTION:In case for ex. 3-2 power-on down-shift is to be made, a duty solenoid valve S2 for C2 is turned off while a duty control valve 11 for C2 is closed so as to disengage a clutch C2. Because the gear train is put in neutral at this time, the number of turbine revolutions of a torque converter 1 is sensed, and when the difference of the product of the number output shaft revolutions of automatic transmission and the Low side gear ratio from the number of turbine revolutions (input shaft revolution) in the portion corresponding to the rise delay is exceeded, the duty ratio of another duty solenoid valve S3 for B1 is raised to a certain value, and brake B1 is engaged through another duty control valve 12 for B1. This prevents generation of shift shocks at the time of kick-down due to blowing-up the engine. |
