| 摘要 |
PROBLEM TO BE SOLVED: To provide a corrosion prevention apparatus for the bored hole of a fluid pipe, in which formation of a bored hole for forming the bored hole in a fluid pipe, and corrosion prevention of the bored hole where a corrosion prevention means is installed in the formed bored hole, are easily performed. SOLUTION: A boring blade includes at least an outer blade 21 having a bored hole diameter larger than that of a bored hole cylinder 20 and forming an inner peripheral face of the bored hole 1a, and an inner blade 22 having a bored hole diameter smaller than that of the outer blade 21. The bored hole cylinder 20 advances axially, rotates around an axis, and forms the bored hole 1a in the fluid pipe 1 and stores a pipe piece 2 thereinside. The bored hole cylinder 20 locks a locking part 31 in a corrosion prevention position where a corrosion prevention cylinder 30 abuts on the inner peripheral face of the bored hole 1a by further axially advancing, and axially recedes while leaving the corrosion prevention cylinder 30 in the corrosion prevention position. COPYRIGHT: (C)2010,JPO&INPIT |
