| 摘要 |
PURPOSE:To enable smooth shift with reduced shift shock by reengaging a release friction element at the time of up-shift operation, after the disengagement, in an automatic transmission for shifting by changeover between engagement and disengagement of plural number of friction elements. CONSTITUTION:The gear trains of an automatic transmission are provided with first and second planetary gear sets 3, 4 composed of plural number of gears between input and output shafts 1, 2, while a computer for shift control carries out engagement and disengagement of gears automatically for shifting based on signals of engine speed sensor 5, turbine rotation sensor 6 and output shaft rotation sensor 7. In this case, at the time of up-shift operation, for example, by supplying oil pressure based on deviation between input shaft rotation variation and an aimed value when the input shaft rotation variation is below the aimed value to a low reverse brake being a release friction element, reengagement of the gears are controlled, thereby eliminating third torque of the output shaft 2 so as to reduce shift shock. |
