| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a control device for an automatic transmission capable of accurately controlling approval and refusal of fail-safe operation. <P>SOLUTION: In the control device for the automatic transmission controlling engagement and release for a plurality of frictional elements 2 to 4 by means of oil pressure of operating oil and switching speed change gears, a first fail-safe valve 23, a second fail-safe valve 24, and a third fail-safe valve 25 are provided in the control device. The first fail-save valve 23 transmits applied oil pressure fed to a third frictional element 4 to the second fail-safe valve 24 when applied oil pressure fed to a first frictional element 2 exceeds a first fixed value. The second fail-safe valve 24 transmits oil pressure fed from the first fail-safe valve 23 to the third fail-safe valve 25 when applied oil pressure fed to a second frictional element 3 exceeds a second fixed value. The third fail-safe valve 25 adjusts applied oil pressure fed to the second frictional element 3 to pressure necessary for releasing when oil pressure fed from the second fail-safe valve 24 exceeds a third fixed value. <P>COPYRIGHT: (C)2003,JPO |
