| 摘要 |
PURPOSE:To reduce a shift shock effectively at the time of performing a desired speed change in the following procedures that a main transmission shifts down or up into a third shift step in jumping over the second shift step from the first one, while a sub transmission shifts up or down contrary. CONSTITUTION:A gear ratio progress RMS of a main transmission at the time of gearshifting is detected, and at a stage where this gear ratio progress RMS reaches setting gear ratio progress RMS1 in and around a second shift step, connection of a clutch K0 of an auxiliary transmission is started. With this clutching, when an automatic transmission shifts to the low speed step side or high speed step side as well as when the sub transmission is shifted at a stage where the main transmission shifts from the first shift speed to the second shift speed, if a varying range of the gear ratio at the first shift speed is larger than that of the gear ratio of the main transmission, the gear ratio shifts to the high speed step side or low speed step side conversely at one period when the automatic transmission is midway in gearshifting, whereby a variation in transfer torque comes severe, and a shift shock is produced there, but this shock is effectively preventable in this way. |
