Improvement to a flexible decoupling joint in an exhaust line of a motor vehicle engine

摘要

Method to prevent deterioration of a decoupling hose mounted between two tubes (7) of an engine exhaust line of a motor vehicle, this hose comprising a deformable inner portion (A), an outer sealing portion (B ) as a continuous and tight envelope with a flexible central zone (12) and two rigid endpieces (15), and an intermediate portion (C) in the form of a wad of thermal lagging (18 ) which extends substantially over the entire length of the outer shell, each rigid cap (15) extending at least over a length such that its peripheral end edge (15a) connected to the flexible central zone (12) comes to lie opposite the inner portion of the hose which is subjected to deformations, characterized in that it consists, for preventing damage to the wad of thermal lagging (18) by said peripheral end edge (15a) each cap, to define the effective length of the shrouds (15) so that for an initial thickness (H _o) of the wad of thermal lagging (18) and a compressed thickness (H _c) of this mattress by said peripheral edge (15a) of each cap during maximum transverse deflection in operation of the inner portion (a) of the hose, the ratio [(H _o -H _c) / H _o] is less than 0.3.