| 摘要 |
<p>PURPOSE:To prevent a control valve from radial displacement and eliminate defective air tightness to a valve seat by providing on the control valve itself a surface engaging radially a member for fixing a control valve in a brake booster. CONSTITUTION:When a brake pedal is treadled to advance an air valve 13 through a rod 15, a control valve 18 correspondingly advances. When a valve 18 is soon seated on a valve seat 24 to cut off communication between a front chamber 6 and rear chamber 7, a brake booster permits differential pressure between both chambers 6, 7 to produce a leftward thrust of a power piston 5. A guide member 23 receives at its rear shoulder a large diameter portion of a spring 22 for urging the valve 18 leftward and bears against a back plate 18a having its front face fixed to the valve 18. The outer peripheral front end 23b of the guide member 23 bears against the inner peripheral surface (engaging surface) 18d of front end of the valve 18 to prevent the valve 18 from radial displacement.</p> |
