| 摘要 |
A hydraulic control system for an automotive automatic transmissions includes a pressure regulator for regulating hydraulic pressure, a pressure reducer having a reducing valve for reducing hydraulic pressure, a shift controller having a manual valve cooperating with a shift selector lever and connected to a plurality of range pressure lines, a pressure controller comprising first, second and third solenoid valves for controlling control pressure reduced by the reducing valve, and first, second and third pressure control valves for controlling hydraulic pressure supplied from the manual valve, the first, second and third pressure control valves being independently controlled by control pressure supplied from the first, second and third solenoid valves, respectively, a switching controller comprising a first switch valve for supplying hydraulic pressure from the first pressure control valve to one of first and second switching lines and a second switch valve for supplying hydraulic pressure from the third pressure control valve and the manual valve to first and second friction elements, a fail-safer comprising a first fail-safe valve for supplying hydraulic pressure from the first switch valve and the manual valve to a friction element operated in low L and reverse R ranges, and a second fail-safe valve for supplying hydraulic pressure from the second pressure control valve to a friction element operated in second and fourth speeds, and an N-R controller comprising an N-R control valve for supplying reverse pressure to a friction element operated in only a reverse R range. |
