CUTTER OF CUTTING AND DIAMETER EXPANDING TOOL, AND CUTTING DIAMETER EXPANDING TOOL USING THE SAME

PROBLEM TO BE SOLVED: To improve a cutter of a cutting and diameter expanding tool used for a pipe splitter method and the cutting and diameter expanding tool using the same.SOLUTION: A cutter of a cutting and diameter expanding tool is drawn by a traction member from one end side in an existing buried pipe to the other end side to cut a wall of the existing pipe along a drawing direction, and it draws a newly installed pipe that is connected behind while expanding a diameter at a cutting point, for replacement. A disc-like cutter of a cutting part of the cutting and diameter expanding tool includes: a blade base part in which at least a blade part of one or more cutters arranged behind in advancing direction of the cutter of the cutting and diameter expanding tool has an angle of 14-50°; a blade tip part having an angle of 60° at a tip end side of the blade base part; and a chamfering part provided by chamfering the tip end of the blade tip part. 【課題】 この発明は、パイプスプリッタ工法に用いる切断拡径具のカッタ及びこれを用いた切断拡径具の改良に関する。【解決手段】埋設された既設管内の一端側から他端側に向けて牽引部材により牽引されて、該既設管壁を牽引方向に切断し切断個所を拡径しながら後方に連結された新設管を引き込んで置き換える切断拡径具のカッタであって、切断拡径具の切断部のディスク状のカッタが、切断拡径具の進行方向で少なくとも後方に配置された１又は複数のカッタの刃部が１４〜５０度の角度を有する刃基部と、該刃基部の先端側で６０度の角度を有する刃先部と、該刃先部の先端を面取りした面取部とからなっていることを特徴とする。【選択図】 図３