| 摘要 |
PROBLEM TO BE SOLVED: To lower weight and costs and reduce noise and kickback by dispensing with a motor driven pump. SOLUTION: When both of solenoids 14, 15 are turned on at the time of decompresion, a pressure difference between both chambers 24, 23 in a negative pressure booster 4 is lowered, and a brake pressure is reduced. In addition, both of solenoid valves 7, 9 are turned on, and the brake fluid in a W/C 8 is discharged to a sump device 10, so that the brake pressure is reduced further. In this process, a pressure difference between both chambers 55, 56 in a vacuum driven pump 51 is also reduced, and respective pistons 54, 61, 62 are retracted, so that brake fluid in the sump device 10 is sucked into both fluid chambers 63, 64. In pressure increase in ABS control, the respective solenoid valves 14, 15, 7, 9 are turned off, and a pressure difference between the both chambers 24, 23 is increased, and as a result, the brake pressure is increased. In this process, a pressure difference between the chambers 55, 56 is also increased, and the respective pistons 54, 61, 62 are moved forward, so that the brake fluid in the both chambers 63, 64 is fed to a MCY 5. |
