BRAKE DEVICE

摘要

PURPOSE: To simplify the entire structure of a brake system by providing an additional pressure control part in a brake booster and applying servo pressure to the pressure control part so as to achieve a driving slip control function. CONSTITUTION: This brake booster 1 having a pushing rod 2a extending toward a master brake cylinder 2 has a pressure connecting part 5 provided with a check valve 6 connected with a servo pressure supply line 4 extending from a pump 3. The pressure connecting part 5 is opened to an annular chamber 7 for surrounding a servo piston 8. Another pressure supply line 11 is connected to the booster 1 through a hole 10 communicating with a pressure accumulator 12. The servo pressure supply line 11 is communicated with a supply line 16 to a pressure cylinder 9 by an inlet port 15 disposed in the booster 1 through solenoid valves 13 and 14. A piston 17 is fitted to the pressure cylinder 9 and is allowed to abut on a slide valve 18 moving in the servo piston 8.