| 摘要 |
The hydraulic control system for an automatic transmission having a plurality of friction elements (C1,C2,C3,C4,C5) includes a pressure regulator (8) which regulates hydraulic pressure produced by an oil pump (4), a plurality of valves selectively supplying hydraulic pressure to the plurality of friction elements. The regulated pressure, reduced in the valve (14) is supplied to a first (18) and second pressure control valve (20) used as control pressures for the different shift stages. Manual valve (16) is connected by line (24) to shift control valve (26) controlled by solenoids (S3,S4) and forming a hydraulic pressure distributer to the shift valves (34,40). A timing control line (50) links the manual valve (16) to the control switch valve (42). Flow of the first speed pressure for friction element (C1) is controlled by a solenoid (S5) on the timing control line (50). Fail safe valve (48) performs fail safe functions with respect to an ideal shift stage when transmission control unit is not operating or when sticking occurs in one of the valves. |
