| 摘要 |
PURPOSE:To realize the application of an automatic speed change gear unit to various kinds of engines, which carries out a feed-back control of hydraulic pressure fed to a frictionally engaging element during shift operation, by computing an initial hydraulic pressure to use this pressure as an initial pressure for the next shift operation. CONSTITUTION:A gear shift mechanism 22 in an automatic speed change gear unit includes a LABINIYO type planetary gear mechanism 38, a front sun gear 44 thereof being coupled with an input shaft 20 through a kick-down drum 52, a front clutch 24 while a ring gear 38 is coupled to an output shaft 30. The rotational speed of the above-mentioned drum 52 is detected by a rotational speed detecting device 142 so that the feed-back control of hydraulic pressure for a kick-down brake 30 is carried out to make the variation rate of the detected rotational speed follow up a desired variation rate. In this arrangement, an initial hydraulic pressure to be fed to the brake 30 after issuance of a shift operation initiating signal is computed in accordance with the hydraulic pressure fed to the brake 30 at the initial time of the feed-back control, and the computed hydraulic pressure is set as an initial hydraulic pressure for the next shift operation. |
