THROUGH HOLE INSERTION CYLINDER USED FOR OUTLET BOX, AND FIRE-PROTECTION MEASURE STRUCTURE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a through hole insertion cylinder, used for an outlet box, that facilitates work to wire an electric wire cable etc., to the outlet box, maintains reliability of the electric wire cable etc., and has superior fire resistance.SOLUTION: There is provided a through hole insertion cylinder used for an outlet box, the through hole insertion cylinder being obtained by cutting a through hole insertion pipe having a groove part at its outer periphery along the groove part. The through hole insertion cylinder may have a thermally expandable fire resistant resin layer and is one of: (1) a through hole insertion cylinder having a cylindrical thermally expandable fire-resistant resin layer on at least one end face of a cylindrical synthetic resin layer; (2) a through hole insertion cylinder having cylindrical synthetic resin layers at both ends of a cylindrical thermally expandable fire-resistant resin layer; and (3) a through hole insertion cylinder formed of a cylindrical thermally expandable fire-resistant resin layer.