某款GDI汽油发动机烧机油现象的研究

Study on Oil Burning of a Certain GDI Engine

烧机油是发动机常见的试验现象之一,尤其是增压缸内直喷汽油发动机,承受较高工作温度和燃烧压力,烧机油现象相对较普遍。机油的额外消耗会减少发动机正常换油里程,导致机燃比失调、加剧运动副磨损,破坏零部件使用功能、影响排放及后处理系统,严重情况下还会导致发动机发生爆燃,发动机动力下降甚至报废。主要分析一款2.0L GDI增压缸内直喷发动机烧机油的影响因素,从一环环高、油环结构、发动机回油结构、增压器机油损耗、气门密封性及活塞环岸结构、缸体网纹参数、配缸间隙、机油温度稳定性方面进行试验分析和验证。结果表明,增加一环环高、改变油环结构、改善回油不畅、优化活塞环岸和环槽结构、机油温度稳定控制、减小网纹参数Rvk均能够改善GDI发动机烧机油现象。

Oil burning is one of the common phenomenons during engine test,especially for turbocharged GDI engine,oil burning is rather common with high operating temperature and pressure. Additional oil consumption will reduce engine oil regular change mileage,lead to oil fuel ratio imbalance,increase kinematic pair wear,damage component using function,influence the emission and after-treatment system,even cause engine deflagration,thus engine power down even scrapped. This paper mainly analyzes the influencing factors of oil burning for a 2.0 L GDI turbocharged GDI engine,including piston ring height,oil ring structure,oil return layout,turbocharger oil loss,valve sealing,piston ring land,cylinder overlapping curve parameters,cylinder clearance and oil temperature stability. With the test analysis and verification,the result indicates that the oil burning of GDI can be improved by increasing piston ring height,changing oil ring structure,improving oil return,optimizing the structures of piston ring land and groove, controlling the oil temperature, and reducing overlapping curve parameter Rvk.