Flexible undulated-walled conduit for decoupling vehicle engine exhaust pipes

摘要

A flexible undulated-walled decoupling conduit (1) for a vehicle engine exhaust system; the conduit being defined by a flexible continuous-walled tubular element (2), and being made of stainless steel sheet (5), which is folded to form a closed conduit and deformed axially to form a number of circular undulations (7) enabling the conduit to flex; the tubular element (2) being covered externally or internally with a woven stainless steel wire sheath (11, 17); the tubular element, according to the invention, having, at each end (3, 4), a group of at least three undulations (20, 21, 22) of increasing inside and/or outside diameters (D1, D2, D3) so as to decrease gradually in height towards the respective end of the tubular element; the undulations (20, 21, 22) in each group being separated by spacings (p1, p2, p3) differing from one another and from the constant spacing of the intermediate undulations (6a); and the undulations so formed conferring greater rigidity to the ends of the flexible conduit in the event of lateral bending stress, so as to achieve substantially uniform stress along the meridians of the undulations (7).