| 摘要 |
An automatic transmission includes a mechanical transmission mechanism coupled to a fluid coupling. The mechanical transmission mechanism has several power trains and several friction engagement mechanisms. By selective supply of actuating fluid pressure to selective ones of the friction engagement mechanisms, various speed stages are provided. A control system for this transmission includes a mechanism for producing a signal representative of engine output and an anti creep device for varying the actuating hydraulic fluid pressure for one of the friction engagement mechanisms which is engaged for providing the lowest speed stage, according to the signal representative of engine output, from a low value when engine output is low upward as engine output increases. The anti creep device may include a hydraulic fluid chamber whose volume alters during alteration of amount of applying of anti creep action, and a fluid conduit system for connecting this hydraulic fluid chamber to the outside with a flow resistance which is different in the outwards direction and the inwards direction. Alternatively, the anti creep device may vary the actuating hydraulic fluid pressure for that one of the friction engagement mechanisms, according to the signal representative of engine output, upward from a low value when the signal is low, as the signal increases, substantially in proportion to the signal, up to a certain value of the signal; and may then set, for values of the signal greater than the certain value, the actuating hydraulic fluid pressure substantially equal to a certain maximum value. |
