| 摘要 |
PURPOSE:To ensure brake liquid pressure from a master cylinder for both front and rear wheels when a dynamic hydraulic controller is disabled, by coupling at least one of two liquid pressure systems with the dynamic hydraulic controller thereby shortening the brake pedal stroke. CONSTITUTION:A changeover valve 60 communicates wheel cylinders 53a, 54a with a port 1g when it is not excited or operated and communicated the wheel cylinders 53a, 54a with a port 1d when it is excited or operated. A pressure sensor 66 is arranged in a liquid pressure path 73 and the changeover valve 60 is driven through an actuator 67 corresponding to the pressure detected through the pressure sensor 66. In other word, the changeover valve 60 is not operated when a predetermined boosted liquid pressure exists in the liquid pressure path 73, but operated when the pressure in the liquid pressure path 73 drops below a predetermined level so as to communicate the wheel cylinders 53a, 54a with the liquid pressure path 72. Consequently, brake force can be ensured for all wheels 51-54 even upon missing of power liquid pressure. |
