长寿命柴油机润滑油抗磨损性能测评方法研究

Study on the Evaluation Method of Anti-Wear Performance of Long-Life Diesel Engine Lubricating Oil

针对中国自主品牌柴油发动机的关键摩擦副测量方法和试验测评工况进行研究,结合润滑油理化分析和关键摩擦副磨损精密测量,形成柴油机润滑油抗磨损性综合评测方法。工况研究显示,延迟喷油正时可在排气温度不超过高温限值的同时实现碳烟的快速生成,加剧摩擦副零件的磨损;提升发动机转矩及降低发动机转速能够有效扩大混合润滑区和边界润滑区占比,利于润滑油抗磨损性的考核。试验结果表明,提出的400 h台架试验后润滑油的老化程度超过了实车100000 km,具有显著的苛刻性;经过两种不同润滑油的6次试验验证,发动机活塞一环失重、活塞油环磨损、缸套磨损、挺柱磨损、连杆上瓦失重等主要摩擦副评价项目具有较好的重复性和区分性,可以作为润滑油抗磨损性能的评价指标。

The measurement methods and test evaluation conditions of key friction pairs of domestic independent brand diesel engines were studied.Combined with the physical and chemical analysis of lubricating oil and the precise measurement of wear of key friction pairs,a comprehensive evaluation method of wear resistance of diesel engine lubricating oil was formed.The study of working conditions shows that delaying the fuel injection timing can realize the rapid generation of soot while the exhaust temperature does not exceed the high temperature limit,and aggravate the wear of friction pair parts.Increasing the engine torque and reducing the engine speed can effectively expand the mixed lubrication area and the proportion of the boundary lubrication area,which is conducive to the assessment of the anti-wear properties of the lubricating oil.The test results show that the aging degree of the lubricating oil after the proposed 400 h bench test exceeds the degree of 100000 kilometers of the actual vehicle,which has a significant harshness.After six tests of two different lubricating oils,the main friction pair evaluation items such as engine piston first ring weight loss,piston oil ring wear,cylinder liner wear,tappet wear,and weight loss on the upper bearing of the connecting rod have good repeatability and distinction,and can be used as the evaluation indexes of the anti-wear performance of lubricating oil.