Silencer

Abstract

A silencer is comprised of an outer sleeve, an inner sleeve having a number of pores, and sound absorbing material including heat-resistant fibers packed between the outer sleeve and the inner sleeve. The sound absorbing material is wound directly around the outside of inner sleeve with two or more turns so that the thickness of wound sound absorbing material around the inner sleeve is greater than dimension of a gap between the inner sleeve and the outer sleeve to give interference between sound absorbing material and the inner and outer sleeves. The sound absorbing material with the inner sleeve is press-fitted into the outer sleeve. According to the present invention, sound absorbing material is prevented from being blown out by exhaust gas flowing through the inside of the inner sleeve so that the silencer is improved in durability. The dimensional stability of the outer diameter of sound absorbing material wound around the inner sleeve can be gained so that the press-fitting operation of sound absorbing material wound around the inner sleeve can be performed stably and the density of sound absorbing material can be stabilized.