| 摘要 |
A speed change mechanism (1) constructed by connecting in tandem a hydraulic type speed change unit (17) having a plurality of hydraulic clutches (57, 58, 59) to be alternatively engaged and a hydraulic type speed change unit (20) having a plurality of hydraulic clutches (66, 67, 68) to be alternatively engaged, wherein a time-varying region (common slip region) is secured in which the two clutches slip in common such that during speed change, when the working hydraulic pressure in a clutch to be engaged is on its way to gradual increase, the working hydraulic pressure in a clutch to be disengaged lowers. This common slip region is made smaller during shift-down than during shift-up by a change in time-difference between the pressure increase start time for the clutch to be engaged and the pressure decrease start time for the clutch to be disengaged or by a change in the pressure decrease property of the clutch to be disengaged, and is maintained constant irrespective of whether one or two hydraulic clutches are engaged and disengaged during speed change respectively or irrespective of a difference in engine rpm. <IMAGE> |
