| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative pressure booster capable of reducing a manufacturing cost.SOLUTION: A diaphragm 15 includes: a plurality of front protruded parts 64 which are protruded to the front side on a front surface 63; and a plurality of rear protruded parts 66 which are protruded to the rear side on a rear surface 65, on a diaphragm flange part 62. A front shell half body 11a includes: a front flange part 72 which is projected to the radial direction outer side and is brought into contact with the front surface 63 of the diaphragm flange part 62; a cylinder part 73; and a front engagement hole 74 with which the front protruded part 64 is engaged. A rear shell half body 11b includes: a rear flange part 82 which is projected to the radial direction outer side and is brought into contact with the rear surface 65 of the diaphragm flange part 62; a circumferential wall part 83 of which the top end is brought into contact with the front flange part 72; and a rear engagement hole 84 with which the rear protruded part 66 is engaged. As the result, a double folding process upon manufacture is disused, processing expenses are reduced, material expenses can be also reduced and a manufacturing cost can be reduced. |
