| 摘要 |
Arrangement for controlling the shifting between two gear ratio ranges in a gear box for motor vehicles, said gear box comprising a main gear box with a number of gear ratios and a two-geared range gear box, coupled to the output shaft of the main gear box, the range gear box having such gear ratios that the total gear ratio of the gear box with the highest ratio in the range box and the lowest ratio in the main box is higher than that with the lower ratio in the range box and the highest ratio in the main box. The shifting in the main box is controlled by a manually operated gear lever and the shifting in the range box by a servo aggregate. The operation of the servo aggregate is controlled by a sensor device sensing the rpm of the output shaft of the range box and a control unit connected to the sensor device and adapted to give a signal for operation of the servo aggregate for shifting of the range box, when at least one predetermined rpm of the output shaft of the range box is passed while increasing or decreasing, means being provided to permit actuation of the servo aggregate only when, during shifting in the main box, the gear lever reaches the neutral position. |
