| 摘要 |
<P>PROBLEM TO BE SOLVED: To surely stop water and sediment from coming out even if sump water gushes out when excavating the ground including a sand aquifer and to minimize the consumption of a pinch valve tube due to wear, thus ensuring service durability for an extended period. <P>SOLUTION: A casing through which a screw is inserted is provided in a leading pipe and a pipe to be buried. The pinch valve device is built in the propelling machine for propelling the pipe to be buried in the ground while drilling the ground by means of a drill head attached at the leading edge of the screw, in which the pinch valve tube 30 for closing a passageway between the casing 12 and the screw 14 by being expanded by the air introduced into a pressurized air chamber 35 formed in the casing 12 is rotatably mounted to the casing 12 and is fixed not to be rotated when the pinch valve tube 30 is in an opened state. <P>COPYRIGHT: (C)2012,JPO&INPIT |
