| 摘要 |
A hydraulic transmission control circuit uses a plurality of solenoid valves (14, 16, 1 20) to control the engagement of friction devices during the shifting of a transmission between gear ratios. A clutch priority valve (34) is provided to prevent the continuous simultaneous engagement of friction devices which will establish more than one ratio. Also provided is a manually controlled valve (3 which permits the operator to determine the range in which the transmission will operate. If the clutch priority valve (34) has been actuated, the transmission ratio can be controlled between a low ratio, for example, second gear, and a high ratio, for example, third or fourth gear, by use of the manual valve (3 in combination with an actuator mode valve (5. The clutch priority valve, when actuated, is also operable to disengage a torque converter clutch. |
