Silencing unit and internal-combustion engine exhaust silencer using same

Abstract

The invention relates to noise control, and provides a silencing unit. The silencing unit comprises a cavity, a partition plate, and an air passage for communicating two sides of the partition plate; the downstream lateral surface of the partition plate is provided with a spiral structure; by using a planar spiral line as a section contour line, a random section of the spiral structure is adapted with the section contour line, and the integral spiral structure is adapted with the shape formed when the section contour line moves along a locus line; and the spiral structure and the adjacent structure form the spiral silencing cavity and the opening thereof by encircling, and the opening is positioned in the propagation direction of sound wave reflected by the adjacent structure at the downstream side of the partition plate. Through the spiral structure, the reflecting probability is increased, the sound wave is captured, attenuation of the sound wave is increased, the silencing quantity is irrelevant with the expansion ratio, and the silencing and structural properties are better. The invention also provides an internal-combustion engine exhaust silencer. By adopting the silencing unit, good silencing and structural properties are ensured; and meanwhile, the upstream side of a random point on the airflow path is positioned at the inlet side of the silencer of the point, and the downstream side of the point is positioned at the outlet side of the silencer of the point, so the power performance of the air is good.

Description

technical field [0001] The invention relates to noise control, in particular to a muffler unit and an internal combustion engine exhaust muffler using the muffler unit. Background technique [0002] The muffler is a device for reducing airflow noise. It is installed in the pipeline or on the inlet and exhaust ports. It has a certain effect on noise reduction when the airflow passes through. Its performance mainly includes three aspects: 1. Noise reduction performance, including noise reduction The size and spectrum characteristics of the sound volume; 2. Aerodynamic performance, usually expressed by the full pressure difference between the inlet and outlet of the muffler; 3. Structural performance, which refers to its overall size, firmness, maintenance requirements, service life, etc. Evaluating the performance of the above three aspects of the muffler is both interrelated and mutually restrictive. From the perspective of the muffler's muffler performance, the greater the m...

AI Technical Summary

Problems solved by technology

Since the silencing volume of the expansion chamber muffler is determined by the expansion ratio, and the silencing frequency characteristic is determined by the length of the expansion part, in order to obtain a large silencing volume and good spectral characteristics, the existing internal combustion engine exhaust mufflers are poor in structure ; Due to the expansion and contraction of the channel section, the expansion chamber muffler will increase the resistance loss, especially when the air velocity is high, the aerodynamic performance will deteriorate, and the labyrinth air flow path will also increase the air resistance, so the exhaust Large air resistance, poor aerodynamic performance, high exhaust back pressure of the internal combustion engine, resulting in loss of power consumption and increased fuel consumption of the internal combustion engine

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