| 摘要 |
PROBLEM TO BE SOLVED: To provide a double tube system pipe excavation device, easily repairable and replaceable in damage and abrasion of an excavation cutter and a bit. SOLUTION: In this double tube system excavation device, the bit 230 is arranged on a cutter head 200 of the excavation cutter 20 so as to be movable outward in the radial direction by receiving pressure in excavation, and movable inward in the radial direction by abutting on a jacking pipe. The bit is constituted so that the outside end in its radial direction is positioned inside an inner surface of the jacking pipe 130 in an inside position in the radial direction, and the outside end in its radial direction is positioned in a position equal to an outside surface of the jacking pipe or on the outside of this position when moving outward in the radial direction. The bit is rockingly installed in the radial direction by an installation arm 210, and an outside position is preferably regulated by a stopper part 200. COPYRIGHT: (C)2006,JPO&NCIPI |
