| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic-hydraulic type control circuit for an electronically controlled power shift transmission. SOLUTION: A control circuit 18 includes system pressure sources 36, 37, a fluid reservoir, a control gallery 38, a plurality of control valves 22, 24, 26, and a plurality of latch valves 32. The control valves 22, 24, 26 and the latch valve 32 are each connected to the corresponding one of clutch packs and communicated with the system pressure sources, the reservoir, and time control gallery 38. The control valves 22, 24, 26, the latch valves 32, and the control gallery 38 cooperate so that the corresponding one of the clutch packs is not pressurized before all the clutch packs are filled with a hydraulic fluid. Further, the control valves 22, 24, 26 and the latch valves 32 cooperate to maintain the disengaged clutch packs at reservoir pressure and to maintain the engaged clutch packs at system pressure. |
