| 摘要 |
PURPOSE:To prevent a rear wheel lock due to delay of a pressure drop in rear wheel brake fluid, by slidably fitting a fail safe piston into a valve body, slidably fitting a pressure reducing piston to a cylinder part of the fail safe piston and obtaining almost approximate rise and fall characteristic curves in brake fluid pressure. CONSTITUTION:A fail safe piston 9 with a stepped difference is slidably fitted to stepped cylinders 5, 6 of a valve body 1, and the first and second pressure reducing pistons 10, 11 are slidably fitted respectively to cylinder parts 9a, 9b of the piston 9. Further a stepped control piston 12 is slidably fitted to stepped cylinders 10a, 10b of the pressure reducing piston 10. This pressure reducing piston 10 is formed in such a manner as to appear with pressure receiving areas A4, A3 (A3>A4) for input-output fluid chambers a1, a2, and normally urged leftward by a holding spring 24. Further spring tension of said spring 24 is set to a specific value in such a manner that this pressure reducing piston 10 is stopped at application of a brake while moved to increase area of the output fluid chamber a2 at release of the brake. |
