| 摘要 |
PURPOSE:To reduce the wall thickness of a valve body and reduce the weight of a device by forming a first passage in between the inner peripheral surface of a cylindrical part and the outer peripheral surface of said valve body. CONSTITUTION:A passage means 41 has a first passage 46 having air tightness by means of a sealing member 45, between the inner peripheral surface of the cylindrical part 9a of a front power piston 9 and the outer peripheral surface of a valve body 6. This first passage 46 is connected to a pressure varying chamber B on a front chamber 4 side via a through hole 47 provided on the cylindrical part 9a, while also to a pressure varying chamber D on the rear chamber 5 side via a second passage 48 formed through the valve body 6. |
