| 摘要 |
PURPOSE:To simplify a booster in structure by holding a valve body in between a power piston and a valve body holding member, holding a bead part of a diaphragm with a bead holding member, and fixing the valve body holding member and the bead holding member together to the power piston as one body. CONSTITUTION:A tubular part 28 at the inner circumferential side of a power piston 21 is stuck close to the circumference of a valve body 20. In this case, such a possibility that a bending moment being added to the valve body 20 from the power piston 21 by dint of differential pressure between a contact pressure chamber 23 and a transformer chamber 24 might grow larger is prevented to the utmost. With this constitution, durability in the valve body 20 is improved. In addition, A lockup of the power piston 21 to a valve body holding member 31 and a bead holding member 33 is performed with a clamping means consisting of a bolt 34 and a nut 35. Therefore structure simplification is so promoted that an assembling becomes facilitated. |
