| 摘要 |
PROBLEM TO BE SOLVED: To provide an improved electrohydraulic control device for power transmission. SOLUTION: A power transmission 16 has a plurality of forward driving ratios, neutral state, and at least one backward driving ratio. Each driving ratio is controlled by the selective engagement of hydraulic operating friction devices C1-C5. The change between the forward driving ratios is controlled by changing the state of at least one friction device. The element for controlling the change of the driving ratios comprises a power source 50, relay valves 64, 66, 88, solenoid control valves 74, 76, 78, and pressure control valves 54, 56. The solenoid valves are electrically operated, and the hydraulic part of the control device can continue the operation of the transmission in a selected driving ratio when the power is interrupted. |
