| 摘要 |
<P>PROBLEM TO BE SOLVED: To make it possible to direct the rotation center of a core cutter for drilling a hole on a main pipe buried in the ground toward the axis of the main pipe. <P>SOLUTION: A guide device 16 is used for a drilling method of drilling a hole 14 on a main pipe 10 to connect a branch pipe thereto, the main pipe 10 being buried in the ground and having a circular sectional shape. The guide device 16 includes a guide member 18 which has a through-hole on its center and an arcuate sectional shape whose inner surface curvature is almost equal to the outer surface curvature of the main pipe, and a display body 28 which has one end and the other end that are fixed to opposed one area 24 and the other area 26 of the guide member, respectively, so that the display body is observed as a linear shape crossing the axis of the main pipe in a view from a plane parallel to the axis of the main pipe when the inner surface of the guide member is stuck closely to the outer surface of the main pipe and which is observed as a non-linear shape when the inner surface of the guide member is not stuck to the outer surface of the main pipe. <P>COPYRIGHT: (C)2012,JPO&INPIT |
