| 摘要 |
PURPOSE: To make internal lock avoidable in both elements by switching simultaneous connection respectively between the first/second friction elements and between the first/third friction elements, mechanically generating a lock, by a single switching means. CONSTITUTION: Both in the case of simultaneous connection between a 2-4 brake 18 and a low reverse clutch 21 at 1-2 speed change time or between a 3-4 clutch 24 and a low reverse clutch 21 at 2-3 speed change time, since a gear case of a ring gear in a planet gear mechanism is fixed, a gear train in the mechanism is locked to cause running incapable. In order to avoid this problem, by switching connection between the 2-4 clutch 24 and the low reverse clutch 21 by the third shift valve 73, simultaneous connection between both the clutches is avoided. In the case of inputting a pressure of oil to a connecting chamber of the low reverse clutch 21 by the second shift valve 72, since a pressure of oil is simultaneously input also to a servo release chamber 35c, simultaneous connection between the 2-4 brake 18 and the low reverse clutch 21 can be avoided. |
