| 摘要 |
PURPOSE:To remove friction between a working member and a reaction member so as to enhance controllability by figuring out a support structure which contains both the reaction member and the end section of an output member in the title device which contains a valve device within a stepped bore formed at the center of a movable body that is moved as a result of negative pressure. CONSTITUTION:This device 1 as referred to the titled has a movable body 10 arranged movably within a main body 6, and an output shaft 15 is fitted onto the forward end of a stepped bore 13 of a cylindrical hub 9 at the center of the movable body 10. And a reaction member 16, a plunger 17, and an input shaft 18 are arranged coaxially with the output shaft 15 described above. Besides, a poppet valve body 23 is provided so that it can be seated both on a valve seat 21 at the outer circumference of the rear end of the plunger 17 and on a valve seat 22 formed at the stepped section of the bore 13. This valve body 13 is a sort of an energizing device which includes a working member 70 and an auxiliary member 81, and is energized so as to be seated on each of valve seats 21 and 22. In this case, the auxiliary member 81 is composed of a cylindrical section 84 which extends along the inner surface of the working member 70. Then, both the end section 51 of the larger diameter portion of the output shaft 15 and the reaction member 16 are housed in the cylindrical section 84 described above. |
