Broadband noise reduction muffler

Abstract

The invention belongs to the technical field of motor vehicle exhaust systems, and particularly relates to a broadband noise reduction muffler. The broadband noise reduction muffler comprises a shell, baffles and cavities, wherein the baffles and the cavities are arranged inside the shell, the baffles include the first baffle, the second baffle and the third baffle which are arranged in sequence, the cavities include the first cavity, the second cavity, the third cavity and the fourth cavity, an air inlet pipe penetrating through the front end face of the shell, the first baffle and the second baffle and an air outlet pipe penetrating through the first baffle, the second baffle, the third baffle and the rear end face of the shell are arranged inside the cavities. The first baffle, the second baffle and the third baffle are provided with a first punching region, a second punching region and a third punching region respectively. The pipe walls, on the first cavity and the second cavity, of the air inlet pipe are provided with a fourth punching region and a fifth punching region respectively. The fourth punching region is sleeved with a first sleeve. The pipe wall, on the second cavity, of the air outlet pipe is provided with a sixth punching region. The sixth punching region is sleeved with a second sleeve. The first sleeve, the second sleeve and the fourth cavity are each internally provided with a sound absorbing material.

Description

Technical field [0001] The invention belongs to the technical field of motor vehicle exhaust systems, and particularly relates to a broadband noise reduction muffler. Background technique [0002] With the development of transportation, the problem of automobile noise pollution has become increasingly prominent, and it has become the most important source of noise pollution in the world today. Among them, exhaust noise is one of the most important noise sources in automobile noise, and the performance of exhaust mufflers directly affects the acoustic quality of automobiles. In the field of automotive mufflers, there are currently three types of commonly used mufflers, namely, resistive mufflers, resistive mufflers and impedance composite mufflers. [0003] The resistive muffler is an absorbing muffler, which uses the sound wave to propagate in the porous sound-absorbing material, and the sound energy is converted into heat energy and dissipated due to friction, so as to achieve th...

AI Technical Summary

Problems solved by technology

[0006] Existing impedance composite mufflers often improve performance by simply adjusting the number of baffles, inner tubes and resistive elements, without making any adjustments to the volume of the chamber, the diameter and number of perforations, the type of sound-absorbing material and its physical characteristics ( Thickness, material density, bulk density, etc.), the actual noise reduction frequency band of these mufflers cannot cover the broadband noise under all vehicle working conditions (such as idling speed, high speed and climbing, etc.), and these mufflers are designed at the beginning Air flow direction and pressure loss are often ignored

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