外文翻譯----降低汽車噪聲的方法-汽車設計-在線瀏覽
2024-07-24 11:19本頁面
【正文】 m the traffic noise, and traffic noise is mainly car noise. It is seriously polluting the urban environment, affecting people39。s life, work and health. So noise control is not only related to fort, but also related to environmental protection. However, all also from the vibration noise, vibration can cause certain parts of the early fatigue damage, thereby reducing the service life of motor vehicles。s laws and regulations, small car in the next decade to control noise standards at the following 76dBA. A number of domestic cities are also planning to traffic trunk lines in 2020 to control noise at the average of less than 70dBA. According to the domestic current data indicate that the domestic value of bus noise permit shall not exceed 82dBA, light trucks for . This shows that our country in the vehicle noise control will have to make do. noise assessment noise evaluation mainly refers to the car, outside noise and vibration adaptive value. Evaluation methods can be divided into subjective evaluation and objective evaluation. Subjective assessment of the impact of vehicle noise is a major factor in fort, loudness and uncertainties, such as semantic differential method can be used for subjective evaluation. At an objective evaluation, can be used PCNM noise measuring device for measuring test analysis。 are threeaxis rotational control balance degrees, to reduce torsional vibration. Electric equipment noise (1) cooling fan noise Cooling fan noise happened devices are subject to wind retaining ring, water pump, radiator and transmission, but the noise generated depends primarily on the chassis. (2) automobile generator noise Automotive generator noise depends on the effects of a variety of sources, these sources have mag source, mechanical and air power source. Noise level depends on the generator magic structure and ventilation systems, as well as generators precision manufacturing and assembly. Body Noise As the speed increased, the body will be more and more noise, and air power are the main causes of noise. Therefore, the following programs to improve the body noise: First, to streamline the design of the body, achieve a smooth transition。 third， interior is softened, such as Inner Mongolia at the roof and body skin the use of soundabsorbing material. In addition, the car at high speed when the tire is also a sour
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