| 摘要 |
<p>At first to third forward speeds, a first clutch apply relay valve (21) is set to a lower shift speed-side position for outputting a first preliminary oil pressure for a hydraulic servo (41) of a clutch (C-1). At fourth to sixth forward speeds, the first clutch apply relay valve (21) is set to a higher shift speed-side position for outputting a second preliminary oil pressure for a hydraulic servo (42) of a clutch (C-2). In a normal state, a second clutch apply relay valve (22) supplies control oil pressures of linear solenoid valves (SLC1, SLC2, SLC3) to the hydraulic servos (41, 42, 43) of the clutches (C-1, C-2, C-3), respectively. In an all-off failure state, the second clutch apply relay valve (22) supplies the first preliminary oil pressure or the second preliminary oil pressure to the hydraulic servos (41, 42), and supplies a line pressure (P L ) to the hydraulic servo (43). Thus, the linear solenoid valves (SLC1, SLC2, SLC3) can be formed by normally closed type linear solenoid valves, and a low shift speed or a high shift speed can be attained even in an all-solenoids-off state.</p> |
