| 摘要 |
PROBLEM TO BE SOLVED: To prevent fault such as racing of engine rotational speed and falling- down of a transmission output torque by delivering operating pressure delaying from switching operation when speed is changed from a speed number for supplying operating pressure in a frictional element fastening chamber toward a speed number which is not supplied. SOLUTION: In the case of delivering of a 3-4 clutch pressure by a second DSV(a duty solenoid valve) at the time of 4-2 shift, base oil pressure Pb and feed back oil pressure Pfb are added, and calculating oil pressure during delivering operation is found out. After a shift command is outputted, until a delay time T1 is lapsed, a duty ratio is held to 0%, and the fastening chamber is made in an operating pressure supplying condition. When the T1 is lapsed, a duty ratio signal corresponding to its calculated oil pressure is outputted until the turbine rotational speed Nt is increased to rotational speed Nt0 <-> just before a shift operation is completed, and feed back control is carried out. When a prescribe time T2 is lapsed after turbine rotational speed is increased to Nt0 <-> , feed back control is completed, the duty ratio is outputted while increasing it to 100%, and clutch pressure is delivered completely. |
