| 摘要 |
PROBLEM TO BE SOLVED: To reduce pulling-in shock and a heating value of a clutch. SOLUTION: A speed change control device of an automatic transmission includes a hydraulic control device, a first speed, and a second speed. The hydraulic control device performs speed change by engagement or disengagement of a plurality of friction-engagement elements, and the first speed is established by the operation of a first friction-engagement element having a first hydraulic switch. The second speed is established by the operation of a second friction-engagement element having a second hydraulic switch, and is placed adjacent to the high-speed side of the first speed. Then the speed change control device of the automatic transmission is provided with a first hydraulic pressure relieving means, a memory means, a computing means, and a second hydraulic relieve means. The first hydraulic pressure relieving means relieves the hydraulic pressure of the first friction-engagement element in accordance with the ON operation of the second hydraulic switch at the time of first up-shift, and the memory means stores the ON time of the second hydraulic switch and the OFF time of the first hydraulic switch at the time of the first up-shift. Then the computing means computes the start time of relieving OFF pressure, and the second hydraulic pressure relieving means relieves the hydraulic pressure of the first friction-engagement element in accordance with the start time of relieving OFF pressure. COPYRIGHT: (C)2008,JPO&INPIT |
