| 摘要 |
PURPOSE:To enable complete engagement, release, normal/reverse both directional driving by a small number of frictional engaging elements by engaging the frictional engaging element by the movement of a second piston and the movement of a first piston, and opening a discharging port by the relative rotation of a casing to the first piston, and then discharging operating oil contained in a first operating oil chamber. CONSTITUTION:When operating oil is supplied to any one or both of a first operating oil chamber 6 and a second operating chamber 13, the frictional engaging element is engaged, and a first member 17 and a second member 22 are engaged with each other. If there is operating oil in the second operating oil chamber 13, operating oil in the second operating oil chamber 3 is drained, and then the casing 2 and the first piston 3 are relatively rotated, as to open a discharging port of operating oil, thereby operating oil in the first operating oil chamber 6 is drained, and the engagement of the frictional engaging element is released, and the engagement of the first member 17a to 17c with the second member 22a to 22c is released. As the result, constituent parts can be omitted because it is not necessary to provide a frictional engaging device for an engine brake separately, and the automatic transmission can be miniaturized and its weight can be lightened. |
