| 摘要 |
PURPOSE:To permit the sudden increase of a reduction ratio and smoothen the restarting of the vehicle by a method wherein the highest hydraulic pressure among a car-speed signal hydraulic pressure, a throttle pressure and a low modulator pressure is utilized as an input hydraulic pressure in a pressure regulating valve outputting a line pressure. CONSTITUTION:A low modulator valve 10 outputs the low modulator pressure which is not depending upon the opening degree of the throttle when a manual valve 70 is set at an L range. Further, the low modulator valve 10 and the throttle valve 40 are arranged in parallel, therefore, the hydraulic pressure which is higher among the low modulator pressure and the throttle pressure is generated in an oil path 2 at the low range. When a sudden down shift is effected, the hydraulic pressure being impressed to a hydraulic servo 570 for an output side pulley becomes higher than usual, therefore, the throttle pressure is increased to increase the line pressure at the low range by the low modulator valve 10 when the opening degree of the throttle valve is small. |
