FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: proposed muffler has cylindrical housing with end face walls in which four chambers are formed by means of cross partitions: inlet, outlet and two additional ones. It has also coaxially arranged inlet and outlet branch pipes and axially arranged intermediate branch pipes located at both sides from housing axis. Spaces of branch pipes are connected to spaces of chambers by means of open cuts and through perforated sections. In all chambers, except for outlet one, cuts of branch pipes, dynamic or imaginary, (beginning of perforated section being located direction of gas flow) along which gas flow passes in or out from corresponding chamber are located in node zones of lower natural resonance oscillations of gas volume enclosed in space of corresponding chamber, that is way said modes are not excited as pressures in modes in zone of excitation is close to zero value (being theoretically zero). Pulsating gas flows at cut of inlet branch pipes are not exposed to correspond resistance, and they do not convey energy to corresponding modes. EFFECT: improved acoustic efficiency of muffler. 1 dwg
