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Silencer

A technology of muffler and Helmz cavity, applied in the direction of sound absorption, muffler device, machine/engine, etc., can solve the problems of affecting acoustic performance, single problem frequency, no supply, etc., to improve absorption efficiency, enhance transmission loss, The effect of increasing the surface area

Inactive Publication Date: 2019-01-04
SHANGHAI TENNECO EXHAUST SYST
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  • Abstract
  • Description
  • Claims
  • Application Information

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

Method used

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Embodiment Construction

[0019] Please refer Figure 1 to Figure 3 As shown, the present invention discloses a muffler, which includes a housing (not shown), an air inlet pipe 1, an air outlet pipe 2 and a connecting pipe 3 connected to the air inlet pipe 1. The housing includes at least a first baffle 4, a second baffle 5, and a Helmz cavity 6 between the first baffle 4 and the second baffle 5. The connecting pipe 3 is provided with an extension portion 31 extending into the Helmtz cavity 6. In the illustrated embodiment of the present invention, the extension portion 31 extends obliquely into the Helmtz cavity 6.

[0020] It is well known that sound waves can be absorbed by viscous and thermally conductive solids. Please refer image 3 As shown, the muffler also includes glass fibers 7 filled in the Helmtz cavity 6, that is, a porous material with a larger surface area is provided in the cavity to absorb more sound energy.

[0021] The Helmtz cavity 6 is a closed cavity with only an air inlet and no a...

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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...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F01N1/04
CPCF01N1/023F01N1/04F01N2310/02
Inventor 钟斌岩严才宝马卓杨润潮印仁军
Owner SHANGHAI TENNECO EXHAUST SYST
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