POWER TRANSMISSION DEVICE AND ITS CONTROL METHOD

To properly perform deceleration slip control, in a power transmission device for transmitting power between an input shaft and an output shaft via at least either of a first power transmission path including a deceleration mechanism and a second power transmission path including a transmission.SOLUTION: When a vehicle decelerates under a prescribed condition that fuel supply to an engine is stopped, a control device of a power transmission device: performs deceleration slip control for controlling hydraulic pressure supplied to a start clutch so that a rotational speed difference between the engine and an input shaft coincides with a target slip speed; boosts line pressure when making a first hydraulic clutch engaged during the execution of the deceleration slip control in a state that power is transmitted between the input shaft and a drive shaft via a second power transmission path; and controls the hydraulic pressure supplied to the start clutch so that the rotational speed difference becomes smaller than the target slip speed while maintaining the boosting of the line pressure before stepping down the line pressure according to the engagement of the first hydraulic clutch.SELECTED DRAWING: Figure 4 【課題】減速機構を含む第１動力伝達経路および変速機を含む第２動力伝達経路の少なくとも何れか一方を介して入力軸と駆動軸との間で動力を伝達する動力伝達装置において減速スリップ制御をより適正に実行する。【解決手段】動力伝達装置の制御装置は、エンジンへの燃料供給が停止される所定条件下で車両が減速する際に、エンジンと入力軸との回転速度差が目標スリップ速度に一致するように発進クラッチに供給される油圧を制御する減速スリップ制御を実行し、第２動力伝達経路を介して入力軸と駆動軸との間で動力が伝達される状態での減速スリップ制御の実行中に第１油圧クラッチを係合させる際にライン圧を昇圧させ、第１油圧クラッチの係合に応じてライン圧を降圧させる前に、ライン圧を昇圧させたまま回転速度差が目標スリップ速度よりも小さくなるように発進クラッチに供給される油圧を制御する。【選択図】図４