| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a double steel pipe suitable for an exhaust pipe for an automobile in which heat insulation or noise insulation is requested, inexpensive and excellent in bendability. SOLUTION: In the double steel pipe comprising an outer pipe 1 and an inner pipe 2, a spacer 3 formed of metal wire in which a part of or the whole of the metal wire is wound around the outer circumference of the inner pipe in an inclined manner by 30-55 deg. with respect to the axial direction is interposed in an annular space 4 between the outer pipe 1 and the inner pipe 2. The spacer 3 formed of the metal wire may include simple metal wire, or a wire net formed of metal wire. If the spacer is formed of simple metal wire, it may be formed of one metal wire, or formed of two metal wires with at least one thereof intersected in an inclined manner by 30-55 deg. with respect to the axial direction of the inner pipe.</p> |
