Exhaust pipe for exhaust system of internal combustion engine of motor vehicle, has sound-absorbing layer with two sound absorption coefficients that are less than specific percentage within specific frequency range

摘要

The pipe (14) has a sound-absorbing layer (20) with a sound absorption coefficient value that is less than 20 percentage with frequencies up to 1000 Hz, and another sound absorption coefficient value less than 40 percentage with frequencies ranging from 1000 Hz to 8000 Hz. The sound-absorbing layer comprises sinter material and metal foam and formed by a fiber mat, a knitted fabric or a fabric, glass fibers, carbon fibers, ceramic fibers and/or metal fibers. The layer is soldered into the pipe.