| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hydraulic control device for an automatic transmission, enabling switching between a fail-safe travelling condition and a fail-safe stopping condition even after the occurrence of a failure. <P>SOLUTION: First, second and fourth solenoid valves S1, S2, S4 and linear solenoid valves SL1-SL5 are normally controlled by a first command system of a first computer so that general functions of the automatic transmission are controlled. The hydraulic control device 20 can establish: a fail-safe travelling condition in which hydraulic pressure is supplied to hydraulic servos 52, 53 of second and third clutches C-2, C-3 during a failure to form a forward travel seven speed stages; and a fail-safe stopping condition in which hydraulic pressure on all hydraulic servos is cut off. After the occurrence of the failure in the first command system, a third solenoid valve S3 is controlled by a second command system of a second computer to select the fail-safe travelling condition or the fail-safe stopping condition. <P>COPYRIGHT: (C)2010,JPO&INPIT |
