| 摘要 |
PROBLEM TO BE SOLVED: To lightening the device at large, by making the mounting hole, for each end of a heat conductive pipe, of a tube seat a projected hole wall made by burring, and fixing the heat conductive pipe, with the bore expansion from inside, in an object where a plurality of heat conductive pipes are fixed between tube seats fixed to both ends of a shell. SOLUTION: For an EGR cooler which is interposed in an EGR system returning a part of the exhaust gas of an engine to an intake system, tube seats 2 are fixed by welding or the like to the peripheries of both ends of a shell 1, and a plurality of heat conductive pipes 4 are arranged and fixed between them. In this case, at fixation to the mounting hole 2' made in the tube seat 2 of the heat conductive pipe 4, burring is applied to the mounting hole 2' of the tube seat 2 so as to make a projecting hole wall 2". Then, a compressive ring 10 is overlaid on this projecting hole wall part 2", and besides the heat conductive pipe 4 is inserted into the mounting hole 2', and the end of the heat conductive pipe 4 is widened from inside by means of a tube expander or the like, whereby it is fixed in press-fitting form to the projecting hole wall 2" part.
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