| 摘要 |
PROBLEM TO BE SOLVED: To provide a boring device and a core cutter for boring capable of reliably boring a manhole wall positioned at the outer peripheral edge of a sewer pipe connected to a manhole by a simple method. SOLUTION: This core cutter 2 of a boring device includes four cutter parts 21-24 in which a plurality of tips 21c-24c are arcuately disposed, respectively, and a support part 40 for supporting the cuter parts movably in the radial direction. The diameter of the core cutter can be reduced by moving the cutter parts in the radial direction, the core cutter can be carried in through the inlet of a manhole without disassembling, and the boring device can be easily assembled in the manhole. Since each of the cutter parts is supported so as to be fixed when each tip is moved to a position corresponding to the manhole wall at the outer peripheral edge of the sewage pipe to be drilled, even when the diameter of the outer peripheral edge of the sewage pipe is large, the manhole wall at the outer peripheral edge of the sewage pipe can be reliably cut and bored by adjusting the radial position of each of the cutter parts. COPYRIGHT: (C)2011,JPO&INPIT |
