Silencer

Abstract

The invention discloses a silencer. The silencer comprises a shell, an air inlet pipe, an air outlet pipe and a connecting pipe connecting with the air inlet pipe, the interior of the shell at least comprises a first baffle, a second baffle and a Helmholtz cavity formed between the first baffle and the second baffle, the connecting pipe is provided with an extension part extending into the Helmholtz cavity, and the silencer further comprises glass fibers arranged in the Helmholtz cavity in a filling manner. According to the arrangement, the surface area of a resistive silencing element is increased, the sound wave absorbing efficiency is improved, the transmission loss of the Helmholtz cavity is increased, and the silencing amount is increased.

Description

Technical field [0001] The invention relates to a muffler, which belongs to the technical field of engine exhaust aftertreatment. Background technique [0002] The Helmtz cavity of the traditional exhaust system is generally: a closed cavity is allocated as a Helmtz cavity separately for a certain muffler. Generally, in order to achieve the target required sound attenuation, a larger Helmtz cavity volume is required, so that it occupies the volume of other basic sound attenuation structures. [0003] Please refer figure 1 As shown, the traditional Helmz chamber is composed of an empty silencer container and a short pipe, which is connected to the main pipe. [0004] According to the calculation formula of Helmtz tuning tone frequency: [0005] [0006] Where, S c And l c They are the cross-sectional area and length of the connecting pipe, V is the cavity volume, and c is the speed of sound. We can find that the tuning frequency is directly proportional to the cross-sectional area of...

AI Technical Summary

Problems solved by technology

[0007] The main feature of the traditional Helmtz cavity is that it can eliminate noise for a specific frequency, which can effectively reduce the individual peaks of the tailpipe noise and make the entire acceleration and deceleration sound smoother; the disadvantage is that if it needs to sacrifice a lot for low frequencies Large sound attenuation volume to achieve the required amount of attenuation, the result will affect the acoustic performance of other frequencies

The volume inside the muffler is limited and in many cases does not provide enough volume for a Helmtz cavity at a single problem frequency, especially low frequency problems that require a large volume

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