接触电阻法在润滑状态测试中的应用研究

发布时间：2018-06-08 23:23

  本文选题：润滑状态 + 接触电阻　； 参考：《大连海事大学》2012年硕士论文

【摘要】：摩擦副润滑状态转变的研究是摩擦学领域的一个重要分支,较为经典的是早期Stribeck曲线,而后Gumbel根据前人研究结果结合Stribeck曲线建立了更为详细的润滑状态转变图。该方法提出的膜厚比是判断润滑状态的一个重要特征参数,本文通过接触电阻法计算出膜厚比完成了润滑状态转变的分析。 本文介绍了利用电阻、电容及阻容振荡等方法测量油膜厚度的原理,通过分析上述几种方法的优缺点,并结合试验机结构特征,确定了适合测量油膜厚度的检测方法,即接触电阻法。首先,基于LabVIEW软件平台开发了接触电阻法的检测系统,该系统包括数据采集模块,人机交换模块,数据处理模块和数据保存模块,完成了采集、预警、滤波处理和数据保存四个功能,获得了摩擦力、接触电压的实时测量结果。测试结果表明：该系统具有检测速度快、精度高、稳定性好等优点。其次通过判断不同载荷下接触电阻分压值,获得了适合本试验电压范围；最后,通过提取的接触电压,分别建立了温度、载荷与膜厚比的统计关系。 通过接触电阻法对铸铁缸套与镀层为氮化铬活塞环的研究得出如下结论： 1.载荷为10MPa、20MPa,电压值在0.1VE01.3V范围内,接触电阻分压值Uc值随恒压源E０值增大而增大；当载荷达到30MPa、40MPa时,接触电压值不受电源电压的影响。可以判断试验电压的选取在E0=0.8～1.5v范围内较为理想。 2.接触电压变化趋势较摩擦力变化趋势更为明显。同时,二者呈现相反趋势,表现为接触电压最大时对应于摩擦力值最小位置,即往复行程的中部位置。接触电压值最小时对应于摩擦力值最大位置,即往复行程的止点位置。 3.行程中部膜厚比随载荷、温度无变化,膜厚比在0.9附近,由此判断该区域处于混合润滑区；止点位置膜厚比随载荷升高而略有下降,在温度为180℃时出现拐点,膜厚比在0.5～0.7之间,由此判断该区域处于边界润滑区；
[Abstract]:The study of lubrication state transition of friction pairs is an important branch of tribology field. The classical Stribeck curve is the classical one. Then Gumbel establishes a more detailed lubrication state transition diagram based on the previous research results and Stribeck curve. The film thickness ratio proposed by this method is an important characteristic parameter to judge the lubrication state. In this paper, the film thickness ratio is calculated by the contact resistance method to complete the analysis of the lubricating state transition. The principle of measuring oil film thickness by capacitance and resistance-capacitance oscillation is discussed. By analyzing the advantages and disadvantages of the above methods and combining with the structural characteristics of the testing machine, the contact resistance method, which is suitable for measuring the oil film thickness, is determined. First of all, based on LabVIEW software platform, a contact resistance detection system is developed. The system includes data acquisition module, man-machine exchange module, data processing module and data saving module. The real-time measurement results of friction and contact voltage are obtained by filtering and data saving. The test results show that the system has the advantages of high detection speed, high accuracy and good stability. Secondly, by judging the partial voltage value of contact resistance under different loads, the suitable voltage range for this test is obtained. Finally, the temperature is established by the extracted contact voltage. The relationship between the load and the film thickness ratio. Through the contact resistance method to study the chromium nitride piston ring of cast iron cylinder liner and coating, the conclusions are as follows: 1. The voltage of contact resistance increases with the increase of constant voltage source E0, and when the load reaches 30 MPA, the contact voltage is not affected by the voltage of power supply. The load is 10 MPA and the voltage is in the range of 0.1VE01.3 V, and the value of UC increases with the increase of constant voltage source E0, and when the load reaches 30 MPA, the contact voltage is not affected by the voltage of the power supply. It can be concluded that the selection of test voltage is ideal in the range of E0. 0. 8 ~ 1. 5 v. The change trend of contact voltage is more obvious than that of friction force. At the same time, the two have the opposite trend, showing that the maximum contact voltage corresponds to the minimum position of the friction force, that is, the middle position of the reciprocating stroke. When the contact voltage value is minimum, it corresponds to the maximum position of the friction force value, that is, the stop point position of the reciprocating stroke. 3. The film thickness ratio in the middle of the stroke is not changed with the load, the temperature is not changed, and the film thickness ratio is close to 0.9. The film thickness ratio at the stop point decreases slightly with the increase of load, and the inflection point appears at 180 鈩，

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