| 摘要 |
PURPOSE:To prevent an abnormal increase of pressure in a body cavity by connecting a body cavity to a fluid passage through a switch valve when pressure in the body cavity reaches a designated pressure. CONSTITUTION:When pressure in a body cavity 10 exceeds a designated permissible range and increases abnormally to reach a designated pressure, the pressure is applied to a control chamber 43, so that a sub-piston 36 is moved to the left against a compression spring 38. A conduit pipe 47 is connected to a conduit pipe 44 connected to a fluid passage 43, and the body cavity 10 is connected to the fluid passage 3 on secondary side. Thus, pressure in the cavity is discharged to the secondary side to prevent abnormal increase of pressure. |
