基于声发射的活塞环-缸套摩擦润滑特征研究  

Research on the Characteristics of Piston Ring-liner Friction Lubrication Based on Acoustic Emission

作　　者：魏娜莎 闫献国[1] 谷丰收[2] 陈峙 WEI Nasha;YAN Xianguo;GU Fengshou;CHEN Zhi(Department of Mechanical Engineering,Taiyuan University of Technology,Taiyuan 030024;Center for Performance and Effectiveness,Huddersfield University,Huddersfield HD13DH,UK)

机构地区：[1]太原科技大学机械工程学院,太原030024 [2]哈德斯菲尔德大学工程与效能中心,英国哈德斯菲尔德HD13DH

出　　处：《机械工程学报》2021年第8期107-114,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51375326);山西省自然科学基金青年基金(201901D211286);山西省自然科学基金青年基金(201701D221134)资助项目;山西省高等学校科技创新(2020L0350);太原科技大学博士科研启动(20192017)。

摘　　要：活塞环-缸套系统摩擦润滑过程产生的声发射信号是湮没在强背景噪声下的非稳态弱信号,特征难以提取和分析。为了有效抑制强噪声,提出一种基于信号物理特征的自适应阈值小波包降噪算法。根据小波包时频分析确定摩擦声发射的最佳特征提取频段,构建基于活塞速度廓形曲线的自适应小波包阈值函数,实现了对表征摩擦润滑的声发射信号的有效提取。将该算法用于分析发动机燃烧试验测得的声发射信号。使用三种不同润滑油(10W30、15W40和旧机油)验证算法的有效性。结果表明,该算法能有效地抑制由阀门开关、燃烧和喷油过程产生的大幅值的噪声。声发射特征值随着润滑油的黏度增大而增大,含有颗粒物的旧机油的声发射特征值随着转速的增大而明显增大。为实现在线监测和诊断活塞环-缸套系统健康状态进而评估润滑油的品质提供了可行的方法。The acoustic emission(AE)signal generated from the friction and lubrication process of the piston ring-cylinder liner system is an unsteady weak signal submerged under strong background noise,and it is difficult to extract and analyze this signal features.In order to effectively suppress strong noise,an adaptive threshold wavelet packet denoising algorithm based on signal physical characteristics is proposed.The optimal feature extraction frequency band of the frictional AE signal is determined according to the wavelet packet time-frequency analysis,and an adaptive wavelet packet threshold function is constructed based on the piston velocity profile curve to extract the AE signals characterising friction and lubrication effectively.The algorithm is used to analyse the AE signal measured in the engine combustion test.Three different lubricants(10 W30,15 W40 and used engine oil)were compared to verify the effectiveness of this algorithm.The results show that this algorithm can effectively suppress the large noise generated from valve switching,combustion and fuel injection.The AE indicator increase with the oil viscosity,and the AE indicator of used oil containing particulates increases with the speed significantly.It provides a feasible method for online monitoring and diagnosing the health status of the piston ring-liner system,and also to evaluate the quality of lubricating oil.

关 键 词：声发射 小波包 活塞环-缸套系统 自适应阈值 

分 类 号：TG156[金属学及工艺—热处理]