Rear Muffler
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The exhaust sound generated from the engine is dampened by the sound-absorbing structure (expansion, interference, sound-absorbing, resonance) incorporated in the muffler. High-temperature exhaust gas is cooled through conduction and heat radiation while passing through the sound-dampening chambers in the muffler. |
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| The configuration responsible for dampening the sound consists of a combination of an expansion chamber, a resonance chamber and a flow division arrangement. Recently, many rear mufflers are equipped with a resonance chamber for low frequencies to reduce the sound in the chamber. Many sound-absorbing mufflers have recently incorporated a sound absorbing structure in part of the muffler inner pipe (bus tube). In these mufflers, sound absorbing materials are placed between the punched internal cylinder pipe and the external cylinder pipe. Manufacturers are improving the sound insulation structures and inventing new ones to achieve the necessary sound dampening characteristics without increasing the resistance to the flow of exhaust gas (back pressure), which affects the engine output. However, because there are limitations in these efforts due to the limited capacity, muffler capacity has increased. Many mufflers have either a round or oval cross-section. A double roll or a double structure is normally used in the shell of the muffler, as it reduces the sound radiating from the shell and prevents corrosion. As a means of reducing sound, beading is often put in the end plate to reduce rigidity. Some mufflers have a double end plate with the sound-absorbing materials placed in between. Some mufflers are also designed to remove condensed liquid from the exhaust gas, which causes corrosion inside the muffler, while others are equipped with a trap to prevent fragments of broken pieces of the catalytic converter from scattering through the tail pipe. |
