| 摘要 |
PROBLEM TO BE SOLVED: To preliminarily cope with a running state where switching of a mechanical engagement mechanism is hard.SOLUTION: An automatic transmission includes a plurality of engagement mechanisms, and the engagement mechanisms have a mechanical engagement mechanism functioning as a brake. The mechanical engagement mechanism can switch a rotational element between a first state of regulating only one-direction rotation and a second state of regulating bidirectional rotation; in a case of a reverse gear, makes the rotational element into the second state; and in a case of a forward lowest gear, enables the rotational element to be made into any of the first state and the second state. When determined to be downhill traveling at the forward lower gear, the automatic transmission switches the rotational element from the second state to the first state.SELECTED DRAWING: Figure 10 |
