| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device for an automatic transmission using a less number of on-off solenoid valves for setting many shift patterns while preventing 5-1 speed down-shift even when a cut valve fails or unexpected hydraulic pressure drop occurs during 5TH travel. SOLUTION: A speed control valve group for controlling hydraulic pressure to be supplied to LOW-5TH clutches comprises three linear solenoid valves, four shift valves and two cut valves for selecting an oil passage to selectively supply line pressure PL or speed control hydraulic pressure to the clutch, and three on-off solenoid valves for controlling the shift valves to be operated. The shift valves are controlled to be operated by the on-off solenoid valves to set a shift stage, but the same on-off operation combined pattern of the on-off solenoid valves is set in cut valve operated and set conditions, respectively, to set a different shift stage. COPYRIGHT: (C)2007,JPO&INPIT |
