| 摘要 |
PURPOSE:To provide high control performance with an easy countermeasure at the time of failure in an automatic brake system further with good responsiveness by interposing a pulsation-preventing bypass oil path, switched to an opened condition at the time of operating an antilock brake system, between a pressure reducing valve and a pressure oil chamber. CONSTITUTION:In an automatic brake device, between a pressure reducing valve 25 and a pressure oil chamber 15 in a brake actuator 4, a pulsation- preventing bypass oil path 61 is interposed in parallel to an ordinary oil path 60. In this pulsation-preventing bypass oil path 61, a check valve 26 is provided in a side of the pressure reducing valve 25, and a pulsation-preventing accumulator 63 serving as a bypass oil path use pulsation-preventing means is interposed in a side of the pressure oil chamber 15. At ABS operation time, an oil path switching valve 64 is switched to transmit oil pressure fluctuation of a brake system, to the downstream of the pulsation-preventing bypass oil path 61 through a master cylinder and a vacuum assist mechanism 1, and the oil pressure fluctuation is absorbed by the pulsation-preventing accumulator 63, and oscillation of the pressure reducing valve 25 is surely avoided. |
