| 摘要 |
PURPOSE:To improve the durability of a friction element and stabilize speed change performance by providing a one-way valve for permitting the flow of oil only in the direction from a regulating pressure oil passage to a pressure source oil passage in between the regulating pressure oil passage and the pressure source oil passage. CONSTITUTION:When an oil pressure is fed to a friction element B/B, a pressure regulating action is carried out as usual by means of a spool 130 and an accumulator piston 132 strokes, gradually increasing a regulating pressure with the lapse of time, to obtain a defined oil pressure relaxing action. On the other hand, when a shift valve is switched over discharging the oil pressure of a pressure source oil passage, since the oil pressure on the regulating pressure oil passage side becomes higher, the oil pressure of the regulating oil pressure passage, i.e., the oil pressure acting on the friction element B/B is discharged through a one-way valve 116. Hence, oil can be rapidly discharged without passing through a pressure regulating valve formed with the spool 130. Thereby, the dragging condition of the friction element B/B can be prevented improving durability. Also, as oil pressure is discharged through the one-way valve 116, speed change performance can be stabilized. |
