Research On Noise And Vibration From Lawn Mower And Its Influence On Human Beings

In 21^st century, a rapid development of lawn mower is happened domestic and overseas, the influence to the society is more and more importance. The development of domestic lawn mower is slower than abroad, further study is less, and the standards have difference, too. The research purpose of this thesis is: under the analysis of parotic noise and the hand-bar vibration of lawn mower from experiment, a scientific foundation of noise and vibration standard establishment related to lawn mower can be made.The concrete contents and results as followings:â‘´An introduction was presented on the development of lawn mowers domestic and overseas. Five different representative types of rotary lawn mowers were chosen to do the experiments under the maximum scale when idling and maximum scale speed when cutting. In addition, a discussion was presented on the data of the noise. According to the data, the parotic noise were over 80dB (A), the maximum value reaching 89dB (A). The frequency of parotic noise from 125¹000 was higher.⑵Experiments of HRV were made according to the different level noise from the mower of different places when the lawn mower was at maximum scale speed cutting by using the ergonomics theory. A analysis was done to analyze the connection between the HRV and the noise according to the experiment data. According to the data, the mean of HRV would be well effected as the noise level increased, the heart rate would increase obviously.⑶Four different types of rotary lawn mowers domestic and overseas were chosen to do the vibration tests at the idling speed and maximum scale speed when cutting. According to Standard ISO 5349, an analysis was done to analyze the data. A study of influence of the vibration from lawn mower to the operator was made to evaluate how many years could the operator work. According to the data, the year of the operator using the four types of lawn mowers before they got vibration disease were 6.636years,9.035years,5.894years and 10.215years.In a word, this thesis used experiment to analyze the noise and vibration of lawn mower from medical physiology and ergonomics combining with noise, vibration and the ergonomics theory. An ameliorating technical performance of lawn mower could be made with the conclusions of the analysis, and a theoretical foundation of establishing noise and vibration standard related to lawn mower could be made with the conclusions, too.