| 摘要 |
PCT No. PCT/EP87/00423 Sec. 371 Date Feb. 7, 1989 Sec. 102(e) Date Feb. 7, 1989 PCT Filed Aug. 1, 1987 PCT Pub. No. WO88/01029 PCT Pub. Date Feb. 11, 1988.Electrohydraulic control for an automatically shiftable automotive transmission with a selection slide valve (2), at least for the neutral position (N), as well as for the drive mode (D) and reverse mode (R), an electronic control device (3) having solenoid valves (4) held in neutral position by spring action, a pressure-medium source (1), pressure control and gear control valves (5, 6, 7) for the actuation of gear engagement couplings and brakes (A-F), as well as with a R-gear safety valve (8), for preventing the shifting into the R-gear when the forward drive speed is still too high, and a system which, in the case of electronic failure, holds or shifts the automatic transmission to one gear insuring that the maximum permissible rotational speed of the engine is not exceeded when the vehicle travels at maximum speed, whereby, in the event of failure of the electronic control device (3) during driving, a control system holds or shifts the gear, and in the event of failure of the electronic control device (3) before the start or the restart of the engine, this control system (5, 6, 7, 8, 9) engages a lower gear. This way, in the case of electronic failure during travel, travel can be continued unhampered, for instance also in the highest gear, and no shifting down takes place. When the electronic device fails at start or at restart after a failure during travel, a lower gear is engaged, wherein it is also possible to start the vehicle. |
