To provide a hydraulic control device of a vehicle automatic transmission that suppresses slipping of a hydraulic frictional engagement device of an automatic transmission, even if a solenoid valve is in failure for generating a switching pressure in a lock-up ready state.
Even if a hydraulic control circuit maintains in the lock-up ready state due to a failure of a second solenoid valve SL2 for generating a second switching pressure PSL2, a lock-up clutch 26 is engaged based on a control pressure (engagement control pressure) PSLU of the linear solenoid valve SLU which increases to the magnitude of engaging the lock-up clutch 26. Accordingly, torque amplification action of a torque converter 14 is eliminated and an input torque Tin which is input to a continuously variable transmission 18 is reduced only by the torque amplification action. As a result, the slipping of the hydraulic frictional engagement device, such as a forward clutch C1, and deterioration in durability caused by the slipping are preferably inhibited.
AYABE ATSUSHI
OGATA YUSUKE
TOYODA SHINYA
| JP2009133434A | 2009-06-18 | |||
| JP2009092210A | 2009-04-30 | |||
| JPH07103330A | 1995-04-18 | |||
| JPH03204474A | 1991-09-06 | |||
| JP2004124964A | 2004-04-22 |
Kojiro Ikeda