| 摘要 |
PURPOSE: To favorably execute shift operation at shifting when one friction element is connected and the other friction element is released, in an automatic transmission provided with an oil pressure chamber for release of a first friction element having oil pressure chambers for connection, and release. and a second friction element having an oil pressure chamber communicated to the oil pressure chamber for release. CONSTITUTION: At shifting 2-3 or shifting 3-2, a shelf pressure during shift operation of a 3-4 clutch 53 is controlled through an oil pressure in a release chamber 54b of a 2-4 brake 54, by a first duty solenoid valve 121 controlling working pressure supplied to a connection chamber 54a of the 2-4 brake 54. In addition to it, the holding time of the shelf pressure is controlled by a second duty solenoid valve 122 controlling working pressure supplied to the release chamber 54b and the oil pressure chamber of the 3-4 clutch 53, so that a time required for smoothly changing turbine rotating speed to the rotating speed after shifting is insured. |
