| 摘要 |
PROBLEM TO BE SOLVED: To surely acquire a great output by a female driver who may not be powerful sufficiently when a strong braking force such as an emergency braking is required. SOLUTION: A ring type member 24 is fitted in the inner circumference part of a valve body 3 freely slidably, and the front side of a valve plunger 8 is fitted in the ring type member 24 freely slidably. A holder 28, to which the second valve element 31 is fitted freely slidably, is connected to the first valve element 27. On the front side and the rear side of the second valve element 31, springs 32, 12 are arranged elastically. A set load of the spring 32 is smaller than the of the spring 12. When a brake booster is operated, a reaction disc 22 is expanded so as to move the ring type member 24 toward the rear side to the valve plunger 8. In this way, the spring 32 is compressed, and the set load of the spring 32 is increased above that of the spring 12, so that the second valve element 31 is moved to the rear side, and as a result, an opening of an atmospheric air valve 16 is increased. |
