INTERNAL COMBUSTION ENGINE MUFFLER Russian patent published in 2002 - IPC

FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: proposed muffler has cylindrical housing with end face walls in which four series chambers are formed by 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 cuts of branch pipes, or imaginary ones (beginning of perforated section being located in direction of gas flow) along which gas flow is directed to or passed from corresponding chamber, are located in node zones of lower natural resonance oscillations of gas volume enclosed in space of corresponding chamber, that is why said modes are not excited as pressure in modes in zone of excitation is close to zero value. Pulsating gas flows at cut of inlet branch pipes are not exposed to corresponding resistance, and they do not convey energy to corresponding modes. EFFECT: improved acoustic efficiency of muffler. 1 dwg