| 摘要 |
PURPOSE:To sharply shorten the shift time by decreasing the operating liquid pressure to the lowest value when the down shift is detected and a friction element is shifted and accelerating the release of the friction element to accelerate the rise of the rotating speed of a power source. CONSTITUTION:When the down shift is detected by a detecting means (c), a liquid pressure lowering means (d) decreases the operating liquid pressure at the time of the shift to the lowest value, the drag by the remaining pressure of the friction device (a) of an automatic transmission is reduced, and its release is accelerated. The rise of the rotating speed of a power source (b) is accelerated. When it is detected that the power source (b) rises to the preset rotating speed by a detecting means (e), the liquid pressure is increased by a liquid pressure returning means (f), the friction element (a) on the low-speed stage side is fastened, and idle rotation is prevented. The shift completion time is predicted by a shift completion time detecting means (g), the liquid pressure is gradually increased by a liquid pressure gradual returning means (h), or it is gradually decreased by the liquid pressure lowering means (d), and a torque fluctuation shock can be reduced. The shift time is sharply shortened, and the shift lag can be reduced. |
