| 摘要 |
PURPOSE:To lighten the shock of speed change in an automatic transmission, by providing a control valve that releases the friction element by discharging hydraulic pressure at the other friction element when the hydraulic pressure supplied to one friction element exceeds a prescribed value. CONSTITUTION:If the valve body 76 of the manual valve 60 is shifted from N range to D range, the line pressure PL is supplied to the brake 58, and the brake 58 is engaged to stop rotation of the input shaft 26. After this, the oil pressure PL working on the clutch 28 and spool valve 84 increases after it receives oil supply delayed by the effect of the orifice 100 to reach a specified pressure. Then the pressure PL displaces the spool valve 84 to the left overcoming the urge of the spring 82. As a result, the port 86 is shut off by the land 78 and at the same time the port 88 is communicated with the port for discharge, and the line oil pressure PL that has been supplied to the brake 58 is discharged and the brake 58 is released to make the input shaft 26 rotatable. |
