| 摘要 |
PURPOSE:To raise braking hydraulic pressure acting on rear wheels as well as to aim at improvements in braking efficiency, by increasing the spring setting load of a proportioning valve and also increasing crossover hydraulic pressure at a time when both front and rear wheel driving systems are in a state of being directly connected. CONSTITUTION:When both front and rear wheel driving systems come into a state of being directly conned, a controller 13 detects it from the output of a sensor 14, driving a motor for a given period of time clockwise. With this rotation, a thrust screw 72 moves upward, and a spring 67 is compressed as far as the specified value due to movement of a receiving member 71 supported on this spring 72. As a result, setting load of this spring 67 increases to some extent whereby crossover hydraulic pressure of a proportioning valve 5 to be varied by this setting load is increased from P0 to P1. |
