液压挖掘机发动机冷却风扇系统降噪研究

发布时间：2019-06-19 06:42

【摘要】：摘要：工程机械给人类社会的发展带来了巨大的贡献,但是,随着工程机械的迅猛发展,它也给人们带来了一些困扰,比如噪声、尾气污染等问题。工程机械的噪声问题已经被多数发达国家所重视,并采取了一系列措施加以整改,甚至还颁布了一系列标准来限制工程机械噪声给人们带来的危害。所以,开展工程机械降噪的研究是十分有意义的。本文以SWE17履带式液压挖掘机为研究对象来开展研究。本课题的研究主要包括以下几个方面：运用DASP噪声测试系统对SWE17微型液压挖掘机的动力室后侧面进行了声强测试,记录了其三维声强图,并对其噪声信号进行了频谱分析,掌握了其声场分布规律,结合导风罩的模态分析以及风扇的旋转频率确定了挖掘机的主要噪声源,为实施降噪提供有效的依据。针对冷却风扇系统引起的空气动力性噪声,本文先建立了风扇以及导流罩的三维实体模型,为流场仿真作准备。运用Ansys软件对实体模型进行了三维流场仿真,得到了导风罩内(包括风扇)的气体流动情况以及它与噪声状况的关系。系统结构参数优化。探讨冷却风扇系统噪声与各参数的关系,包括风扇和导风罩的位置关系、叶尖间隙以及导风罩形状等等。对优化后的冷却风扇系统进行噪声测试,整机噪声的声压级下降0.8dB(A)左右,风扇系统部位声强级下降1dB(A)左右。
[Abstract]:Abstract: construction machinery has brought great contributions to the development of human society, but with the rapid development of construction machinery, it has also brought some problems to people, such as noise, tail gas pollution and so on. The noise problem of construction machinery has been paid attention to by most developed countries, and a series of measures have been taken to correct it, and even a series of standards have been promulgated to limit the harm caused by the noise of construction machinery. Therefore, it is very meaningful to carry out the research of noise reduction of construction machinery. In this paper, SWE17 crawler hydraulic excavator as the research object. The research of this subject mainly includes the following aspects: the sound intensity of the rear side of the power chamber of SWE17 micro hydraulic excavator is measured by using DASP noise test system, the three-dimensional sound intensity diagram is recorded, the spectrum analysis of its noise signal is carried out, the distribution law of sound field is mastered, and the main noise source of excavator is determined according to the modal analysis of air guide cover and the rotating frequency of fan. It provides an effective basis for noise reduction. Aiming at the aerodynamic noise caused by cooling fan system, the three-dimensional solid model of fan and guide cover is established in this paper, which prepares for the simulation of flow field. The three-dimensional flow field of the solid model is simulated by Ansys software, and the gas flow in the air guide cover (including the fan) and its relationship with the noise condition are obtained. The structural parameters of the system are optimized. The relationship between the noise of the cooling fan system and the parameters is discussed, including the position relationship between the fan and the guide cover, the tip clearance and the shape of the guide cover, and so on. The noise test of the optimized cooling fan system shows that the sound pressure level of the whole machine noise decreases by about 0.8dB (A), and the sound intensity level of the fan system decreases by about 1dB (A).
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU621;TB535

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