| 摘要 |
<P>PROBLEM TO BE SOLVED: To replace only an inner surface layer stained by dust, by separating from a thermal insulation layer, in a thermal insulation duct having the inner surface layer and the thermal insulation layer formed of a resin foam and fiber arranged on its outside. <P>SOLUTION: This thermal insulation duct has the inner surface layer formed by keeping a shape in a cylindrical shape by a hard spiral reinforcing body, by connecting its mutual side edges, by spirally winding a flexible tape, and the thermal insulation layer formed outside the inner surface layer; and is constituted so as to be freely extracted and inserted from the thermal insulation layer, by moving in the shaft direction by spirally rotating the inner surface layer, by threadedly engaging the hard spiral reinforcing body with a spiral recessed groove formed on an inner peripheral surface of the thermal insulation layer. The thermal insulation layer is composed of a first foaming layer formed by closely and spirally winding a first foaming resin tape and a second foaming layer formed by spirally winding a second foaming resin tape at a predetermined interval on an inner peripheral surface of the first foaming layer; and is constituted in a spiral recessed groove of the thermal insulation layer with spiral clearance between the mutual adjacent second foaming resin tapes. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
