采用低黏度润滑油对发动机性能的影响

摘要

车用发动机通过使用低黏度的润滑油，可获得更大的动力性和经济性。以某1�5L4缸自然吸气发动机为例，研究采用较低黏度的SM 5W20代替原使用的SM 5W30对发动机性能的影响。采用Flowmaster软件建立发动机润滑系统模型，分析润滑油黏度对发动机润滑系统润滑油压力、流量和润滑油泵功耗的影响，分析表明，采用较低黏度的SM 5W20代替SM 5W30，润滑系统的流量增大了0�83％～6�72％，润滑油压力降低1�45％～5�98％，润滑油泵功耗降低了1�4％～6�58％。通过发动机台架试验，研究黏度对发动机摩擦功、功率、扭矩及油耗的影响，结果表明，使用SM 5W20比使用SM 5W30的发动机摩擦功低，在中低速下的燃油经济性提升。%The vehicle engine can obtain more dynamic and economy by using low viscosity engine oil. By taking the 1�5 L L4 naturally aspirated gasoline engine for an example,the influence was studied on engine performance by using low viscosity oil SM 5W20 to replace SM 5W30. By using the lubrication system model of engine established by Flowmaster software,the influence of oil viscosity on pressure,flow and oil pump power dissipation of engine lubrication system was an⁃alyzed.It is showed that,oil flow of the system is increased by 0�83%—6�72% ,oil pressure is decreased by 1�45%—5�98% and oil pump power dissipation is decreased by 1�4%—6�58% by using low oil viscosity of SM 5W20 to replace SM 5W30.The influence oil viscosity on engine friction,power,torque and fuel consumption was studied on engine test platform.The results show that,engine friction power is more lower by using SM 5W20 than using SM 5W30,and engine fu⁃el economy is improved in the low to middle speed.