| 摘要 |
<p><P>PROBLEM TO BE SOLVED: 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. <P>SOLUTION: 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 P<SB POS="POST">SL2</SB>, a lock-up clutch 26 is engaged based on a control pressure (engagement control pressure) P<SB POS="POST">SLU</SB>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. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
