| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a flexible tube made of thin material for an exhaust gas pipe equipped with a multi-layer bellows with reduced number of air leak holes of high resformance with low cost and less man-hours. SOLUTION: This flexible tube for an exhaust gas pipe is equipped with a bellows 1 being made of an inner layer pipe 11 and an outer layer pipe 12 as a material and comprising alternating parts of crest 1a and trough 1b to absorb the relative displacement of exhaust gas pipes being connected to both ends by deformation that follows an input force. At the pipe material forming stage where plates are rounded into the pipe material for the bellows 1, welded beads are provided beforehand so as to protrude from the pipes' peripheral surfaces. The pipes having the welded beads superposed concentrically. An air path 3 is made to communicate with both sides of the welded beads in the longitudinal direction and air leak holes 4a, 4b to communicate through the air path 3 with outside air by bulge forming that are made pastially swelling when pressurized outward.</p> |
