| 摘要 |
PURPOSE:To eliminate the shortage of brake force, by providing a brake holding valve between a pressure regulator valve and pressure generating source, increasing pressure through a fail-safe mechanism higher than a normal level at pressure decrease in the other system and providing the fail-safe mechanism in said pressure regulator valve. CONSTITUTION:A pressure generating source A is connected to right front and left rear wheel brakes 8, 10 through a brake holding valve D and the first valve part 4 in a fluid pressure control valve E' in one system, while connected to left front and right rear brakes 12, 14 through the second valve part 6 of the fluid pressure control valve E' in the other system. The first and second valve parts 4, 6 are controlled with pressure reducing control start pressure in accordance with a spring 76 in a common spring part 70. A brake is applied, after a vehicle is perfectly stopped, if a pedal 57 is released, pressure in the downstream side of the holding valve D is held in that state. Here pressure in a side of the second valve part 6 is decreased, and tension of the spring 76, applied to a pressure control plunger 79 in the first valve part 4, is increased, thus the valve is opened to increase pressure in the rear wheel brake 10. |
