| 摘要 |
PURPOSE:To control line pressure to be of the magnitude necessary but minimum during operations through a stepped transmitting path by constituting line pressure to be or not to be applied to the second feed-backing port of a line pressure regulating valve depending on the case when either of the stepped transmitting path or a stepless transmitting path is selected. CONSTITUTION:A switching valve 114 applies line pressure to a second feed- backing port 518 when a stepped transmitting path is selected. This thereby allows line pressure to be applied to a first and the second feed-backing port 522 and 518, the bearing area of line pressure acting as feed-backing signal pressure, is made large in size, so that line pressure to be regulated is thereby made low. On the other hand, when it is directed to make switch-over to a stepless transmitting path, the switching valve 114 is switched, hydraulic pressure is discharged out of the second feed-backing port 218, this thereby allows the bearing area of line pressure acting as feed-backing signal pressure to a line pressure regulating valve 120 to be decreased, so that line pressure to be regulated is thereby made high. |
