发动机油油压报警问题研究

A Research On Engine Oil Pressure Alarm Problem

发动机油压直接表征了发动机摩擦副的润滑供油状况,是从宏观上衡量发动机油润滑情况的重要参数,通过在德国BBC台架和桑塔纳化油器发动机实际行车试验中对发动机油油压特性的系统定量研究,考察了在各种发动机工况下不同粘度和质量等级发动机油的油压特性。试验结果表明:在相同工况下,发动机油油度等级是影响油压的主要因素;质量等级对油压影响不大;同一粘度等级发动机油的添加剂剂量和类型对油压贡献不大;单级油和多级油油压特性相近;同一粘度等级发动机油,其发动机转速是影响油压的主要因素,实际行车试验数据表明:各种发动机油的油压一般大于发动机厂商规定的下限值,在怠速偏低和苛刻行驶后油温偏高的共同作用下,低粘度等级发动机油会出出现油压偏低的情况,从理论上回归所得的结果表明,发动机油温度过高会大大降低循环油路发动机油粘度。

Engine oil pressure directly indicates the status of lube oil supply to the engine friction pairs, and thusbe used as an important parameter to macroscopically evaluate the engine oil lubrication. The engine oil pressure characteristic is systematically and quantitatively studied using German BBC bench tests and Santana carburator engine on-road tests, to investigate the oil pressure of various oil brands with different viscosity and different quality ,and under different working conditions. The result shows that under the same working condition, viscosity of the engine oil isthe major factor to influence oil pressure while the quality grade has no obvious effect on the oil pressure. For the oilswith same viscosity grade, the quantity and type of addivtives have only trivial effect on the oil pressure. The oil pressure characteristic of single-band oil is similar to the multi-band oil. For the oils with same viscosity grade, the engine's r.p.m, is the major factor to influence the oil pressure. On-road test datas show that the oil pressure of various brands is usually higher than the lower limitation specified by the manufacturer. Sometimes at lower idle speed andhigher oil temperature (after a travel under severn conditions)may result in lower pressure for the engine oil with lowerviscosity. Theoretical regression shows that the over-temperature of engine oil may dramatically reduce the viscosity ofoil in the oil loop, thus impair the oil pressure and lubrication performance.