| 摘要 |
PROBLEM TO BE SOLVED: To optimize oil pressures acting on the frictional engagement elements of an automatic transmission during speed-change that requires simultaneous control of engaged-side and disengaged-side oil pressures, even on fluctuations of the input shaft torque. SOLUTION: An input-shaft torque estimating part A estimates the output torque of an engine from the quantity of engine intake air and the engine speed and then estimates the torque of the transmission input shaft from the estimated engine output torque and the torque ratio of the torque converter. Depending upon the type of speed change, a torque-distribution ratio setting part B computes torque distribution ratios applied to the frictional engagement elements before and after the speed change. From the estimated input shaft torque and torque distribution ratios, a required torque calculating part C calculates torques required in the engagement elements. Lastly, a required oil-pressure calculating part D transforms the required torques into oil pressures required to act on the engagement elements. The oil pressures of the engagement elements are thus controlled to the required oil pressures thus obtained. |
