| 摘要 |
PURPOSE:To obviate a throttle valve mechanism for governing a line pressure by duty-controlling the second solenoid supplying pressure oil to a relay valve feeding a control pressure of oil to a lockup control valve and a cutback valve. CONSTITUTION:In the time of 1-, 2-speed, an oil line l is drained switching a solenoid relay valve 29 to a right half position, when duty ratio of the second solenoid 15 is changed in accordance with throttle opening, a pressure of oil, governed by a modulator valve 27, acts on a cutback valve 5 supplying a low pressure to a primary regulator valve 2. In a condition of 3-, 4-speed, the relay valve 29 is switched to a left half position, when duty ratio of the second solenoid 15 is changed in accordance with the throttle opening, a pressure of oil, governed by the valve 27, acts on a lockup control valve 6 adjusting a degree of engagement of a lockup clutch 31. Here the valve 5 supplies a low pressure to the valve 2 governing a line pressure to a low fixed value. Thus, the necessity for providing a line pressure governing throttle valve can be eliminated. |
