| 摘要 |
PURPOSE:To eliminate a speed change shock without an accumulator for a high speed engagement element for a high speed step at the time of shifting from the high speed step down to a low speed step by way of releasing a hydraulic engagement element for the high speed step in the state of previously engaging with a hydraulic engagement element for a low speed step establishing the low speed step by way of cooperating with a one-way clutch. CONSTITUTION:An oil passage L8 connected to an oil passage L7 linked with a hydraulic engagement element C2 for a high speed step through a shift valve 14 existing at a right position is connected to an oil feeding passage L3 by switching over to a left position of a shift valve 13, and by feeding oil to the element C2, the high speed step is established. By a hydraulic control valve 24, oil feeding pressure can be controlled to increase and decrease through a pressure regulating valve 23. At the time of shifting down, initially, the shift valve 13 is held at the left position, the oil feeding pressure is decompressed until slippage is caused to the element C2, thereafter, it is maintained in the decompressed state until a one-way clutch of a low speed step is engaged, and thereafter, by switching the shift valve 13 over to the right position, oil is discharged from the element C2. |
