| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic transmission which precludes the shift operation from becoming out of function by enabling the Y-direction motion even if a linear solenoid valve is in the normal close condition. SOLUTION: The automatic transmission performs shift control automatically by controlling the shift direction using an ECU 1, configured with a piston 43 inserted into a cylinder 40, a spring 44 installed in one of the chambers 41, and a mechanical valve 4 energized so that the piston 43 is moved toward the other chamber 42, whereby the pressure in a first chamber 31 having smaller pressure receiving area of a piston 33 of a shift actuator 3 is supplied to a second chamber 32 having greater pressure receiving area of the piston 33 of the shift actuator 3 through a first linear solenoid valve 2 in the normal closed condition, and at the time of fail safe when the first linear solenoid valve 2 is out of function to feed the current, the piston 33 is moved toward the first chamber 31 having smaller pressure receiving area. |
