Patent ID: 6729354
Filing Date: 2004-05-04
Classification: B21D,F01N,F16L,Y10T

Abstract:
A double-pipe-structure hollow member comprising:an inner pipe formed as a hollow pipe; an outer pipe formed as a hollow pipe and disposed concentrically on an outer peripheral side of the inner pipe, wherein an outer periphery of the inner pipe and an inner periphery of the outer pipe are fittingly superposed; each of the inner pipe and the outer pipe includes a cone shaped portion, the cone shaped portion of the inner pipe and the cone shaped portion of the outer pipe being fittingly superposed in contact with each other; one of the cone portion of the inner pipe and the cone portion of the outer pipe defines holes through which fluid can flow between the inner and outer pipes; and each of the inner pipe and the outer pipe includes a central portion, an outer periphery of the central portion of the inner pipe being spaced from an inner periphery of the central portion of the inner pipe.