| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance assembly efficiency and to improve operation efficiency of a pressure increase valve and a pressure reduction valve in a vehicular brake device capable of boosting a wheel brake. <P>SOLUTION: A control piston 90 is coaxially interconnected to a rear end of a reaction force piston 92 having a front end facing a booster hydraulic control chamber 130; the pressure reduction valve 117 is constituted by a pressure reduction valve seat 146 provided on the reaction force piston 92, and a poppet type pressure reduction valve element 147 spring-energized to a rear part while the rearmost position is regulated; the pressure increase valve 116 is constituted by a pressure increase valve seat 161 forming a pressure increase valve hole 163 through which a front end of the pressure reduction valve element 147 can be inserted and provided on a valve housing 118, and a poppet type pressure increase valve element 162 capable of being pushed to the front part by the front end of the pressure reduction valve element 147 and spring-energized to the rear part; and a seal area of the pressure increase valve element 162 at seated in the pressure valve seat 161 is almost equal to a front end pressure receiving area of the pressure increase valve element 162 receiving the hydraulic pressure of a booster hydraulic chamber 25. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
