Muffler for an exhaust system of an internal combustion engine

Abstract

The present invention describes a muffler for an exhaust system of an internal combustion engine. The muffler (10) includes a housing (12), a through pipe (14) that conducts exhaust gas during operation of the muffler (10) and is guided through the housing (12), and a branch pipe (16) fluidically branching off from the through pipe (14) within the housing (12). The branch pipe (16) has an upstreamend at the through pipe (14) and ends freely and open at an end face with a downstream end within the housing (12). The branch pipe (16) has a length from the upstream to the downstream end or up toa lateral recess which has a cross-sectional area which is greater than half a pipe cross-section of the branch pipe (16). The branch pipe (16) has downstream perforations (18) in a section from 3 / 8 of the length as measured from the upstream end A total area of the downstream perforations (18) is smaller than half the pipe cross-section of the branch pipe (16), and no perforations or upstream perforations (40) have a total area of at most 10% of the pipe cross-section of the branch pipe (16) being present in a section before 3 / 8 of the length.

Description

technical field [0001] The invention relates to a muffler, in particular for the exhaust system of an internal combustion engine for a motor vehicle. Background technique [0002] Exhaust systems for internal combustion engines usually include mufflers to reduce disturbing noise, in particular charge exchange noise. For this purpose, the silencer can be provided with branch pipes. Such silencers typically have Helmholtz resonators or bypass silencers. [0003] However, depending on flow rate and temperature, such branch pipes tend to produce undesirable whistling noises. Such noises can be very annoying and difficult to predict during the development phase, since they only partially occur under certain driving conditions, for example after a cold start and at 80% engine load. [0004] To reduce disturbing noise, avoid sharp edges in the exhaust flow path. However, this is not always possible or associated with very high costs. For example, it may be necessary to use hal...

AI Technical Summary

Problems solved by technology

[0005] To make matters worse, as the decisive edge in the form of sharp edges can vary during production, the disturbing noise in the exhaust system can also vary greatly

Therefore, it is difficult to ensure a constant good quality of the exhaust system in terms of noise generation

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