Vehicle IC engine exhaust systems - has flexible strip wound into polygonal section spiral sealed along edges by folded seam

摘要

The flexible element for vehicle IC engine exhaust is made from alloy steel strip with ratios of width formed to element bore between 1 : 2.5 and 1 : 4.0; to thickness 40 : 1. This strip is formed into a polygonal section tube by winding into a spiral with 15 - 20 sides (2) per turn and joining turns by a folded seam. Width of the unfolded, radial, portion (9) of the formed strip is about four times the thickness. The polygon-forming folds in the strip are perpendicular to its edges; angled about 5 deg. to the tube axis. Tube ends fit into annular gaps between circular section internal pipes (4) and external sleeves (6), all three being welded bonded together.