Oil film thickness measurement system of crankshaft based on ultrasonic reflection signal
ZHANG Yun1, LIANG Guangshun1, CAO Cong2, TANG Zhiyong3
1. Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China; 2. School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China; 3. Neijiang Jinhong crankshaft Co., Ltd., Neijiang 641000, China
Abstract:The performance of an internal combustion engine is related to the lubrication state of the crankshaft. In this paper, a thickness measurement system is developed using an ultrasonic reflection signal to monitor the change of oil film thickness in real time. Based on acoustic theory, the relationship between oil film thickness and acoustic reflection coefficient in multilayer media is derived, and the application methods of the spring, resonance, and phase shift models are given. For the crankshaft, the oil film thickness ranges from 0 to 50 μm, an ultrasonic double crystal straight probe with a center frequency of 1.056 MHz is used to generate and receive the ultrasonic signal, and a long axis with four annular grooves with different depths is processed to obtain the functional relationship between the oil film thickness and the spectral peak of the acoustic reflection signal. To calculate the oil film thickness, the fitted linear model is embedded into LabVIEW software. The test shows that the relative error of the measurement system is less than 10%, and the oil film thickness can be measured well.
张云, 梁光顺, 曹聪, 唐志勇. 基于超声波反射信号的曲轴油膜厚度测量系统[J]. 清华大学学报(自然科学版), 2022, 62(9): 1484-1491.
ZHANG Yun, LIANG Guangshun, CAO Cong, TANG Zhiyong. Oil film thickness measurement system of crankshaft based on ultrasonic reflection signal. Journal of Tsinghua University(Science and Technology), 2022, 62(9): 1484-1491.
[1] 程林凯. 表面织构特征参数及分布对润滑性能的影响[D]. 西安: 西安理工大学, 2021. CHENG L K. The influence of surface texture characteristic parameters and distribution on lubrication performance[D]. Xi'an: Xi'an University of Technology, 2021. (in Chinese) [2] 鲁剑. 内燃机曲轴轴承润滑影响因素的研究进展[J]. 内燃机与配件, 2020(19): 17-18. LU J. Research progress on influencing factors of crankshaft bearing lubrication of internal combustion engine[J]. Internal Combustion Engine & Parts, 2020(19): 17-18. (in Chinese) [3] 唐伟坤. 超声膜厚测量机理及传感器研究[D]. 南京: 南京航空航天大学, 2011. TANG W K. Research on the mechanism for ultrasonic measurement of film thickness and designing sensor[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2011. (in Chinese) [4] DWYER-JOYCE R S, DRINKWATER B W, DONOHOE C J. The measurement of lubricant–film thickness using ultrasound[J]. Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 2003, 459(2032): 957-976. [5] 李响, 马希直, 张步高. 油膜厚度超声测量声反射系数理论及数值计算[J]. 润滑与密封, 2018, 43(9): 13-18, 27. LI X, MA X Z, ZHANG B G. Theory and numerical calculation of acoustic reflection coefficient for oil film thickness measurement[J]. Lubrication Engineering, 2018, 43(9): 13-18, 27. (in Chinese) [6] POPINCEANU N G, GAFIŢANU M D, CREŢU S S, et al. Rolling bearing fatigue life and EHL theory[J]. Wear, 1977, 45(1): 17-32. [7] SAKI K, TAKAHASHI F, ARAI M. Measurement of journal center locus in diesel engine bearings[J]. Mitsubishi Heavy Industries Technical Review, 1987, 24(3): 1-4. [8] 侯克平, 温诗铸. 重载条件下线接触弹流问题的数值分析[J]. 清华大学学报(自然科学版), 1985(3): 1-10. HOU K P, WEN S Z. A numerical analysis for the EHD problem at heavy loads in line contacts[J]. Journal of Tsinghua University (Science and Technology), 1985(3): 1-10. (in Chinese) [9] 程林. 基于电容法的油膜厚度测量技术研究[D]. 大连: 大连海事大学, 2012. CHENG L. Research on the measurement technology of oil film thickness based on the method of capacitance[D]. Dalian: Dalian Maritime University, 2012. (in Chinese) [10] 张文法, 温诗铸. 应用光干涉法研究弹流油膜厚度和形状[J]. 润滑与密封, 1983(1): 8-12, 19. ZHANG W F, WEN S Z. An experimental investigation of oil film thickness and shape under EHL condition using optical interferometry[J]. Lubrication Engineering, 1983(1): 8-12, 19. (in Chinese) [11] 王学锋, 郭峰, 杨沛然. 纳/微米弹流油膜厚度测量系统[J]. 摩擦学学报, 2006, 26(2): 150-154. WANG X F, GUO F, YANG P R. A film measuring system for elastohydrodynamic lubrication from nano to micro thickness[J]. Tribology, 2006, 26(2): 150-154. (in Chinese) [12] 张平, 张小栋, 刘春翔. 光纤传感器多点测量润滑油膜厚度方法[J]. 振动、 测试与诊断, 2011, 31(5): 618-621. ZHANG P, ZHANG X D, LIU C X. Multi-point measurement of bearing oil film based on fiber-optical sensor[J]. Journal of Vibration, Measurement & Diagnosis, 2011, 31(5): 618-621. (in Chinese) [13] 赵妮. 滑动轴承油膜厚度光纤检测传感器设计与实验研究[D]. 西安: 西安建筑科技大学, 2017. ZHAO N. Design and experimental study of fiber optic sensor for oil film thickness of journal bearing[D]. Xi'an: Xi'an University of Architecture and Technology, 2017. (in Chinese) [14] 杨晓. 超声膜厚测量方法及测量系统的研究[D]. 南京: 南京航空航天大学, 2014. YANG X. Research on the ultrasonic measurement method and the measurement system for the oil-film thickness[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2014. (in Chinese) [15] 汪剑云. 圆柱滚子轴承润滑油膜厚度超声测量方法及实验研究[D]. 哈尔滨: 哈尔滨工业大学, 2019. WANG J Y. The measurement method and experimental research of lubricating oil film thickness of cylindrical roller bearings using ultrasound[D]. Harbin: Harbin Institute of Technology, 2019. (in Chinese) [16] 张步高. 超声膜厚测量电路及实验研究[D]. 南京: 南京航空航天大学, 2019. ZHANG B G. Circuit and experiment research on ultra-sonic oil film thickness measurement[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2019. (in Chinese) [17] ZORPAS A A, INGLEZAKIS V J. Automotive industry challenges in meeting EU 2015 environmental standard[J]. Technology in Society, 2012, 34(1): 55-83. [18] KINRA V K, JAMINET P T, ZHU C, et al. Simultaneous measurement of the acoustical properties of a thin‐layered medium: The inverse problem[J]. The Journal of the Acoustical Society of America, 1994, 95(6): 3059-3074. [19] PIALUCHA T, CAWLEY P. The detection of thin embedded layers using normal incidence ultrasound[J]. Ultrasonics, 1994, 32(6): 431-440. [20] 王波, 马希直, 张步高. 超声法测量油膜厚度的系统设计[J]. 机械制造与自动化, 2020, 49(5): 146-149. WANG B, MA X Z, ZHANG B G. System design of oil film thickness measurement by ultrasonic method[J]. Machine Building & Automation, 2020, 49(5): 146-149. (in Chinese) [21] REDDYHOFF T, KASOLANG S, DWYER-JOYCE R S, et al. The phase shift of an ultrasonic pulse at an oil layer and determination of film thickness[J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2005, 219(6): 387-400.