Protective structure of the through hole end face of base material, bushing and apparatus for forming protective structure on the through hole end surface of the base material

摘要

PROBLEM TO BE SOLVED: To provide a protection structure of a through-hole end face in a substrate material, a bushing, and a device for a boring tool and the bushing.;SOLUTION: In a protection structure for an end face of a through-hole in a substrate material, a bushing is attached in the through-hole provided in a substrate material 100 having an approximately U-shaped cross section installed as a substrate on a wall or a ceiling rear face. The circumference of the through-hole is formed in a state of being recessed more than an outer face of the substrate material in which the through-hole is provided so as to be retracted into an inside of the substrate material. The bushing includes a flange part provided at one end and a protection part for preventing the through-hole from coming into sliding contact with end faces of wiring and piping materials through-arranged in the through hole. The protection part covers the end face of the through-hole recesses into the inside of the substrate material, the flange part is accommodated in a recess in the circumference of the through-hole formed by retraction of the flange part, and the bushing is attached to the substrate material without protrusion of the bushing from the outer face of the substrate material.;COPYRIGHT: (C)2013,JPO&INPIT