| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative pressure booster equipped with an electromagnetic auxiliary controlling means which can introduce the atmosphere to a working chamber in compliance with the operating mode, i.e., normal braking or emergency braking, using a single valve element, and which is structured simple and works with a good responsiveness. SOLUTION: A valve element 301 energized by a spring toward the reversing limit is installed on an input member 52 in such a way that the specified stroke (s) can be shifted to the front or rear, and a solenoid 16 of an electromagnetic auxiliary controlling means and a stationary core 18 are fastened to a valve cylinder 10 coupled with booster pistons 4 and 6, and a movable core 21 conforming the stationary core 18 is coupled with the valve element 301 , and in case the solenoid 16 is energized when the input member 52 advances, the moving core 21 is operated so that the advancing amount of the valve element 301 relative to the valve cylinder 10 (degree of communication opening in the middle between the working chambers 2b and 3b and the atmosphere) increases beyond the advancing amount generated by the input member 52. |
