【作者】 李立民；

【导师】 冯忠绪；

【作者基本信息】 长安大学 ， 机械设计及理论， 2013， 博士

【摘要】 随着市场竞争的日趋激烈和环保法规的日益严格，工程机械噪声问题越来越受关注。我国工程机械产品噪声水平偏高，如何降低工程机械的整机噪声水平、满足法律法规的要求，同时兼顾整机的动力性、经济性要求，已成为衡量工程机械整机技术性能的重要指标。论文以国内某工程机械厂家生产的某型号双钢轮振动压路机为研究对象，采取理论分析、试验研究和数值仿真相结合的方法进行了整机噪声控制的研究。从理论上分析了压路机整机各噪声源产生的机理及其特性，详细分析了振动压路机整机降噪技术开发需求，提出了制定整机噪声控制目标的基本原则和方法，并将整机噪声的总控制目标分配至各子系统，提出了整机噪声的开发流程。基于噪声信号测试与分析技术开展了原始噪声的工程试验。通过噪声主观评价、原始噪声摸底试验对样机的现有噪声水平进行了评估，通过样机声强测试、频谱测试与分析对样机的噪声源进行了识别，确定了整机噪声的泄露部位及各测点处的主要噪声源，为整机噪声的有效防控指明了方向。对标机型主客观试验与样机试验同步进行，对比试验发现国产样机与国外对标机之间的噪声性能指标存在较大的差距，根据对比试验结果确定了整机噪声控制的目标，并为噪声防控提供了改进方向。由于频谱试验结果中的排气噪声对整机噪声水平影响较大，我国工程机械行业对消声器的噪声却鲜有研究，开展了排气消声器噪声及其性能的专项试验研究。对排气消声器的优化改进采取理论分析、数值仿真分析及试验研究的综合措施，改进优化后装机试验表明：改进后消声器的综合性能改善明显，较样机原消声器消声性能增加1~3dB（A），空气动力性提高约8%。提出了噪声源控制与传播途径阻隔相结合的、面向工程应用的整机噪声控制方法，采取噪声源控制、关键子系统噪声优化和整机声学封装等措施相结合的噪声综合控制措施，将发动机和液压泵安装舱进行声学封装，同时通过采取增强发动机的散热能力，合理匹配机器行走和振动液压系统的工作参数及控制起步起振加速度变化规律，降低了功率需求，减少了系统的溢流发热，保证了发动机和液压系统连续正常工作的热平衡，上述措施的实施较好地解决了压路机主要噪声源的噪声问题。通过结构改进、参数优化等噪声控制关键技术的实施，改进后样机司机耳旁噪声性能优于进口机型压路机的水平，整机左右侧噪声优于国标规定值，样机改进后噪声性能得到了很大改善，降噪效果显著。论文提出的整机噪声控制策略对压路机噪声防治的效果显著，也对其他工程机械噪声的防治具有重要的参考价值。更多还原

【Abstract】 With the increasingly serious competition market and strict environmental regulations,construction mechanical noise problem becomes more and more attention. The constructionmachinery products high noise level in our country, the problems that how to reduce theroller’s noise level and meet the requirements of laws and regulations, at the same time, makesure the dynamic performance and fuel economy have become an important index thatevaluates holistic performance of construction machinery. In this thesis, a domestic tandemvibratory roller was taken as research model, combine theoretical analysis and numericalsimulation method for noise control on the tandem vibratory roller.This thesis analyzes the mechanism of production and its characteristics of roller noisefrom the aspect of theory, expounds the requirements of noise control of constructionmachinery, and sets the noise control target and provides the basic principle and measures ofnoise control, and put the whole machine noise control target into each subsystem, and thenoise control process was established.Tandem roller’s original noise experiment is carried out on the basis of technologies ofnoise test and analysis. To evaluate the noise level via the experiments of prototype noisesubjective evaluation and original noise tests, to make sure noise leaked parts and noisesources via noise intensity test and spectrum test, which points out the direction of effectiveprevention and control for the whole machine noise control. A foreign tandem roller’s test iscarried out simultaneously. There is a big gap on noise level between prototype and foreigntype roller. The contrast test determine the domestic machine’s control target, and provides adirection of noise control.The spectrum test shows that exhaust noise has a great influence for the whole noiselevel, while there is little research on construction machinery’s muffler, so this thesis iscarried out a special noise experiment study on the performance of exhaust muffler.Combined theory analysis, numerical simulation and experimental study to optimize mufflerdesign.The muffler special experiment and installed research shows that the eliminationperformance of redesign muffler increased1~3dB (A), and the air performance increased about8%.This thesis presents a engineering application noise control measures of combining noisesource control and transmission path, via the implementation of noise source control, the keysubsystem optimization and acoustic package, he cabin in which installs engine and pump hasbeen acoustic package, enhancing the performance of cooling system by taking intelligentspeed regulation fan, reasonable setting hydraulic system parameters, are taken to reduce theheat which generate by walking and vibration hydraulic systems, and by staggering instantpower peak of walking and vibration hydraulic system, that cloud reduce engine maximumpower and keep continuous normal operation of engine and hydraulic system, these measuresare thoroughly solve the tandem roller noise.With the noise control measures taken to the prototype, which includes structureimproved and parameters optimization, the improved experimental shows that it has a greateffect on noise control, the driver ear’s noise level is superior to the imported roller, noise atthe prototype’s left and right sides of7.5m is better than national standard specified value.the improved roller’s noise performance improves a lot, and the noise reduction effect isobvious.The whole machine noise control strategies are remarkable for the tandem roller’s noisecontrol in this thesis, which also has an important reference value for other type ofconstruction machinery.更多还原