汽车发动机缸套-活塞环摩擦副磨损及对策

本文分析了汽车发动机缸套-活塞环摩擦副的磨损特点，探讨其磨损的机理，提出了减少摩擦、控制磨损的具体措施。     

Wear Condition Monitoring and Working Pattern Recognition of Piston Rings and Cylinder Liners Using On-Line Visual Ferrograph

This study applies stepped loading and stepped velocity approaches to simulate the actual working conditions of gasoline engines. Accelerated wear tests were conducted for piston rings and cylinder liners under different lubricating conditions by using a self-made pin-on-disc wear machine equipped with an on-line visual ferrograph (OLVF) for wear monitoring. The wear coefficients for oil monitoring were extracted to distinguish between constant conditions and stepped changing conditions. A similarity model for oil monitoring was constructed and the monitoring data sets of similar working conditions were grouped together. Results show that the OLVF monitoring system can be used to obtain the real-time variation in debris concentration. The index of particle coverage area (IPCA) of OLVF increases abruptly after the load or speed changes. The similarity model can evaluate the similarity of the variation trend of IPCA under different operating conditions. The relationship between IPCA and working conditions was examined in this study and provides an essential support to wear monitoring and life prediction of engines.     

缸套—活塞环材料在往复滑动中摩擦系数的试验研究

为了研究机车柴油机缸套活塞环材料的摩擦学性能,我们设计并制造了一台往复式摩擦磨损试验机。该试验机可在一定范围内实行载荷、速度、润滑量的单因素控制,并可同时定性和定量的显示运动中的摩擦力大小。我们利用该试验机对美国GE公司采用的软氮化铸铁缸套—表面镀铬铸铁活塞环材料进行了摩擦学性能的试验研究,得出了该配对副在往复滑动中摩擦系数随载荷和速度变化的关系曲线。     

表面氮化对活塞环摩擦磨损参数的影响分析

用摩擦磨损试验机对铸铁活塞环在氮化前后与高硼铜铸铁缸套配合分别进行了半小时和一小时摩擦磨损试验,测量了氮化前后的活塞环表面摩擦系数和磨损量、磨损率,并对磨痕进行了分析。结果表明:未氮化活塞环摩擦系数大于氮化环,摩擦系数变化稳定性比氮化活塞环差,未氮化环磨损量较氮化环增大了约39.6%(半小时)及51.0%(一小时),未氮化环磨损率的一小时试验比半小时试验平均升高6.7%,氮化环磨损率降低了13.7%,与未氮化环配合的缸套磨损量较与氮化环配合的缸套的磨损量和磨损率与活塞环比较规律一致,表面磨痕显示未氮化环磨损剧烈,由此氮化处理提高活塞环-缸套摩擦副的稳定性,且耐磨性得到提高。     

Friction and Wear of Low-Phosphorus Engine Oils with Additional Molybdenum and Boron Compounds,Measured on a Reciprocating Lubricant Tester

Previous research has already extensively characterized the effects of a variety of engine oils on engine performance. However, low-phosphorus engine oils, which are of growing importance due to the reduction of automotive emissions, have not been studied much. This paper sets forth the results of an initial investigation involving the effects of low-phosphorus engine oils on the friction and wear characteristics of typical engine cylinder kit components from a 3.8-liter, four-cylinder engine. For these tests, sections of molybdenum-coated piston rings were oscillated against segments of production cast iron cylinder bores. The oils were evaluated under two sets of conditions; i.e., the frequency of 20 Hz and a load of 60 N and a frequency of 40 Hz and a load of 120 N. The friction coefficients were continuously recorded, and the wear depths on the cylinder bore segments were measured at the conclusion of each experiment. The oils consisted of low-phosphorus prototype oil (LPPO) containing 0.05 wt% phosphorus, which is half the amount of ZDDP in GF–3 oils, and the LPPO treated with six different supplemental antiwear, anti-friction additives. The remaining additives in the LPPO were present in the amount required for full GF–3 formulation. The supplemental additives were selected to lower friction and replace and/or enhance antioxidant and antiwear properties lost due to lower zinc dithiophosphate (ZDDP) content. The results of low phosphorus concentration oils were compared to the results obtained with formulated ILSAC GF-3 engine oil. The oils that contained organomolybdenum ester showed the greatest benefit in friction reduction in the two different operating conditions. SEM/EDS/XPS surface analyses on the surfaces run with oils containing organomolybdenum ester showed evidence of molybdenum compound formation on the cylinder bore surface. In addition, antiwear film formation mechanisms due to surface interaction among the ZnDTP, organomolybdenum compounds, and metal oxides are discussed.     

摩擦力测量机构的有限元分析设计

摩擦力的测量始终是摩擦磨损试验机的重要组成部分之一。设计实践中，涉及到测量原理、机构的选择及设计计算等一系列问题。通过比较几种常见的摩擦力测试机构的原理，介绍了采用有限元分析技术对笔者在设计过程中选用的一种弹性臂摩擦力测试机构进行结构设计，获得了较优方案。     

A Study of Torn and Folded Metal (TFM) on Honed Cylinder Bore Surfaces

Torn and folded metal (TFM) on honed cylinder bore surfaces has been observed and studied for decades. However, there is no objective and quantitative method for ranking the severity of TFM. Studies on its effect on the scuffing resistance of a cylinder bore and piston skirt/piston ring are also very limited. Machined surfaces are currently evaluated and ranked qualitatively based on fax film images. The results may vary greatly depending upon the individual's experience and also the image quality. In this study, an attempt has been made to develop a method that can be used to evaluate cylinder bore surfaces objectively. A “surface index” has been developed for classifying honed bore surfaces. To further examine the effect of TFM on a cylinder bore performance, bench tests have been conducted to evaluate cylinder bore scuffing resistance and its correlation with the bore surface quality in terms of the value of the surface index.     

汽车发动机活塞环的磨损分析及提高活塞环使用寿命的对策

本文对汽车发动机活塞环磨损的特征及原因进行分析，给出在高温、高压、高速和润滑困难的条件下，延长活塞环的使用寿命的对策及正确安装活塞环的要领。     

降低气缸套磨损的一些方法

针对柴油机气缸套磨损对发动机造成的危害,以及缩短发动机使用寿命的问题,在分析研究的基础上提出减少柴油机气缸磨损的措施,从而提高柴油机的使用寿命.     

快速磨损试验机及其试验方法

本文运用摩擦这的系统分析方法,提出内燃机缸套－－活塞环快速磨损试验的磨损形式－条件模拟原则,研制成功了快速磨损试验机,并完成了试验方法的定型化研究。     

关于内燃机缸套活塞环磨合过程的数学模型

从混合润滑和磨合动力学的角度出发，以表面粗糙度和磨损率为状态参量，建立一个关于内燃机缸套、活塞环摩擦学系统磨合过程的数学模型，分析了影响磨合过程的各种参数对磨合的影响，为磨合过程的动态仿真提供了基于润滑的表面形貌分析的理论依据     

Effect of Bio-Lubricant and Biodiesel-Contaminated Lubricant on Tribological Behavior of Cylinder Liner–Piston Ring Combination

This article addresses the issue of friction and wear characteristics of diesel engine cylinder liner–piston ring combinations under different lubricating conditions using a pin-on-disc wear tribometer. The discs were made out of actual engine cylinder liner material using a casting process. Pins were made out of top compression ring material. The tests were conducted on a pin-on-disc tribometer for wear and friction characteristics of the cylinder liner and piston ring combination with diesel-contaminated rapeseed oil–based bio-lubricant, diesel-contaminated commercial synthetic lubrication oil (SAE 20W40), biodiesel-contaminated commercial synthetic lubrication oil (SAE 20W40), and used (150 h) commercial synthetic lubrication oil (SAE 20W40). Experimental results demonstrated that the rapeseed oil–based bio-lubricant and biodiesel-contaminated synthetic lubricant exhibited better performance in terms of wear, friction, and frictional force under similar operating conditions. Thus, usage of newly formulated bio-lubricant and biodiesel in the long run may have a positive impact on engine life.     

无油润滑压缩机活塞环的研究进展

为实现压缩机的无油润滑，需采用无润滑活塞环。无润滑活塞环由自润滑材料制造。本文分析了常用自润滑材料，如填充聚四氟乙烯、填充聚酰亚胺等的性能及工程应用，并报道了金属材料、复合型填充聚四氟乙烯、CFRP等新材料。介绍了整体开口活塞环及无背压活塞环的结构、特点、应用及设计计算。对活塞环结构型式的研究进展，如T型环、压力平衡环、超短迷宫式无托环整体无背压活塞环、一槽双环等作了介绍，并展望了无润滑活塞环的研究前景。     

The Friction and Wear Model of Steels and Their Probable Statistic Calculations

Based on a systematic analysis of steel wear surfaces by Scanning Electron Microscopy (SEM) and Auger Electron Microscopy (AES), a statistical model for friction and wear of steels is proposed. Three categories of contact are proposed; oxide-oxide, metal-metal, and metal-oxide. Each category of contact is related to a probability distribution on the real contact area. Using a new concept of nascently exposed metallic surfaces, this paper derived the mathematical expressions for the friction coefficient and wear rate by means of statistical methods. The calculated values are in good agreement with measured values.     

活塞式压缩机"拉缸"原因分析及防范措施

分析了活塞式压缩机"拉缸"现象的原因,提出了排除"拉缸"故障的防范措施.     

轴向柱塞泵柱塞与缸体孔泄漏及工艺分析

为了提高轴向柱塞泵的容积效率及整体寿命,研究了柱塞和缸体孔的泄漏流量与缸体孔的转角关系,通过Matlab仿真了其曲线图,得出了泄漏流量随着缸体孔的转角增大而变大,而根据泄漏的标准在正常工作的情况下不能超过0.25ml/min,确定了其间隙在范围内其泄漏流量是较小的,为了得到这个间隙进一步对柱塞和缸体的工艺进行了详细的分析,最终通过千分尺测量柱塞与缸体孔的配合间隙是符合设计要求的,从而提高了轴向柱塞泵的容积效率和整体的寿命。     

内燃机活塞裙部配缸间隙对裙部润滑影响的研究

本文建立的数学模型主要是结合动力学方程及缸套 -活塞裙部间的流体动力润滑方程 ,采用数值分析方法来研究活塞的二阶运动 ,并从减小活塞裙部摩擦功耗和减小活塞横向运动的角度 ,对活塞与缸套的最佳油膜间隙进行了确定 ,使得活塞裙部与缸套的间隙更为合理     

A Study of Piston Friction Force in an Internal Combustion Engine

Quantitative estimation of friction losses in the initial design stage of an automobile engine is a crucial issue that determines the fuel economy and performance of the automobile. However, measurements and mathematical treatments of friction losses were difficult, and practical estimation methods were scarce.

This study was carried out due to such circumstances, with emphasis placed on the analysis of mechanism of friction losses of the piston system, and the introduction of practical equations for calculation of those friction losses.     

摩擦磨损试验机在线检测系统

现代摩擦学的试验研究对摩擦磨损试验机的测量系统提出了更高的要求。本文介绍了自行设计的强电流摩擦磨损试验机及其实时在线检测系统,主要包括试验中各参量信号的获取,A/D转换,以及对测量数据误差的软件处理方法。     

Friction and Wear Transitions in Carbons (Temperature and Stress Analysis)

In this paper, the friction and wear behavior of a carbon composite is studied. Friction tests were performed under constant friction mode. The power inputs were increased gradually to study their effects on friction transition at ambient air environment. Friction surfaces were examined using various macro and nanoscopic techniques to understand the evolution of friction transition. Structural changes of friction film have been observed from graphitic allotropic form to amorphous type structure. This sudden change leads to an increase of the coefficient of friction. It seems that the inter-laminar shearing, disruption of the film and sample cracking might cause the friction transition. Analysis from stress field simulation shows that cracks were more likely to occur at the trailing edge of the sample at the end of transition. This study shows that any type of failure (mechanical or thermal fatigue) of the friction film or bulk material is sufficient to generate friction and wear instabilities.