| 摘要 |
PROBLEM TO BE SOLVED: To provide an improved power transmission controller. SOLUTION: A power transmission has a plurality of forward drive ratios, neutral conditions, and at least one rear drive ratio. Each drive ratio is controlled according to selective engagement of hydraulic pressure operated frictional devices C1-C5 such as clutch and brake. Change between the forward drive ratios is controlled by changing the condition of at least one frictional device. The device controlling the change therebetween includes a pressure source, relay valves 64, 66, 88, solenoid controlled valves 74, 76, 78 and pressure control valve 56, and the like. The solenoid controlled valve operates electrically, and the hydraulic part of the controller can continue operation of the transmission at the selected drive ratio, at the time of interruption of power. |
