| 摘要 |
PURPOSE:To improve the responsiveness of the switchover of speed change by providing a second oil passage for linking a working fluid pressure regulating valve with a gentle fit-in valve to a speed change switchover valve, and providing a transient position for draining the working fluid through the second oil passage on a portion where the speed change switchover valve is in a switchover transient time. CONSTITUTION:A second oil passage 30 for linking a pressure regulating valve 50 with a gentle fit-in valve to a speed change switchover valve 4 is provided in such a way that a port which is blocked by a gentle fit-in valve 22 in the course of returning so as to make a working fluid pressure in a first oil passage 9 a defined value higher than a first set pressure while lower than a second set pressure, is linked to a back pressure oil passage 21, while providing a transient position 4c for draining the working fluid through the second oil passage 30 in a portion where the speed change switchover valve 4 is in a switchover transient time. Thereby, the shock of connecting a clutch at the time of switching over the speed change switchover valve 4 can be lowered, reducing the time of raising a pressure to a defined value while improving the responsiveness of the switchover of speed change. |
