Abstract: A muffler for an internal combustion engine for effectively damping noise over a wide frequency range, from low frequency noise to high frequency noise. An absorber packed type muffler adapted to absorb noise by a sound absorbing material is inserted in and fixed to a housing which has a bore or bores thereinside, thereby forming one of a pipe inserted type muffler, a resonance type muffler and an interference type muffler to attain combined characteristics of both the types of mufflers.

Abstract: A method of rigidly connecting a plate and a tube such as those of a muffler associated with an internal combustion engine. The plate is formed with an eyelet by burring or like technique and, then, the tube is inserted into the eyelet as far as a predetermined position. A stop is placed to backup the plate at a flat surface of the latter where a flange produced by the eyelet is absent. This is followed by driving a die to compress the flange in such a manner as to reduce the diameter of the eyelet, thereby plastically deforming the flange. Part of the flange proportional to the decrease in diameter is caused to thrust into the periphery of the tube.