| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a hydraulic control device for multi-step type automatic transmission capable of restricting occurrence of irregular simultaneous engagement of frictional engagement elements even in the case that all-on-fail occurs in a plurality of linear solenoid valves.SOLUTION: This invention comprises an oil pressure supply part 21; linear solenoid valves SL1 to SL6 that can adjust an oil pressure PL and supply oil to hydraulic servos 31 to 36; each of the hydraulic servos 31, 32 for at least two frictional engagement elements C-1, C-2 where at least any one of a plurality of frictional engagement elements is always engaged when an advancing range is formed; and the first changing-over valve 24 arranged in at least two hydraulic passages a4 to a7 between at least two linear solenoid valves SL1, SL2 connected to each of the hydraulic servos 31, 32 in a plurality of linear solenoid valves and that can be changed over to the first position where the oil passages a4 to a7 are communicated and the second position where the oil passages a4 to a7 are shut off.</p> |
