润滑表面膜在线电测技术研究

为了在线研究摩擦副中表面膜的变化，提出采用摩擦副间的动态接触电阻定性地表征表面膜状态的测试技术．测量电路包括四臂电桥测电阻，信号放大、光耦隔离等模块．针对往复运动的特点，提出了可揭示表面膜状态的数据处理方法，并在自制的缸套／活塞环摩擦试验机上进行润滑条件下表面膜形成和损伤的试验研究．研究表明：采用接触电阻法可在线观测表面膜的形成、损伤及恢复等表面膜变化比较显著的过程．

Online Measurement of Lubrication Surface Films Using Electrical Method

In order to investigate the change of surface films online,a measurement technique was put forware this pater.The status of surface films can be expressed qualitatively by the dynamic electrical contact resistanc (ECR)between tribological pairs.The measurement circuit mainly includes a four-arm bridge,a signal amplifie module,and a linear optocoupler module,etc.A methodology,which can indicate the status of surface films un der reciprocating sliding,is proposed for ECR signals.The experimental test was performed on a home-mad machine,which simulated reciprocating lubricated cylinder bore/piston ring pairs.The investigations show that ECR method is successful to monitor the surface films online under some conditions such as formation,damage and heal of surface films,etc.where the change is dramatic.