| 摘要 |
PURPOSE:To shorten the distance between a power piston and a sealing member by forming a first axial direction passage at the outer position of a diaphragm nipping part, and allowing a first communication passage to communicate with each constant pressure chamber through a second passage formed on the bulging-out part of the cylindrical part of a front shell and a through hole on a center plate. CONSTITUTION:The outer peripheral part of a diaphragm 16 is nipped between the annular wall part 2C of a front shell 2 and the opposed wall part 5C of a center plate 5. A first axial direction passage 34 is formed on the outer side in the radial direction from the nipped part and between the large diameter cylindrical part 2B of the front shell 2 and the outer peripheral surface of the diaphragm 16, and communicates to a constant pressure chamber C through a through hole 5D formed on the center plate 5. Further, the first passage 34 communicates with a constant pressure chamber A through the second passage 35 in the bulging-out part at a part of the cylindrical part 2A of the front shell and a part of the annular wall part 2C. Therefore, the constant pressure passage is not closed by a sealing member 13, even in the reciprocating movement of a power piston 15, and the whole length of the device can be shortened. |
