| 摘要 |
PURPOSE:To ensure durability even if anything should happen by judging the correlation between the rotating speed of an output shaft of an automatic speed change gear and the rotating speed of a rotating member other than the output shaft or an engine in consideration of a speed change gear ratio to increase the control oil pressure when the correlation is shifted from the proper relation. CONSTITUTION:The correlation between the rotating speed of an output shaft of an automatic speed change gear and the rotating speed of a rotting member other than the output shaft or the rotating speed of an engine is judged in consideration of a gear ratio of a speed change step. At the time of abnormality, that is, when the correlation between them is shifted from the proper relation by slippage of a frictional engagement device, the oil pressure in a hydraulic control device is increased. Therefore, even if the control oil pressure is decreased by a trouble in a sensor system, resulting in slippage in the frictional engagement device, the slippage is quickly detected to return to the proper condition. Accordingly, the control oil pressure of the frictional engagement device can be maintained sufficiently even during non-speed change running to ensure durability if anything should happen. |
