润滑油对发动机曲轴摩擦功影响的仿真与试验研究

摘要

The multi‐body dynamic simulation model of the crankshaft for an inline 3‐cylinder gasoline engine was established by using EXCITE tool of AVL software and verified by the bench test .The influences of lubricating oil temperature ,pressure and type on the friction power loss of engine crankshaft were analyzed with the model .The research was found that the friction power losses of simulation result and bench test are 106 .6 W and 102 W respectively under certain operating conditions .The er‐ror between them was less than 5% ,which proved that the model was feasible .The crankshaft friction power loss dropped to the minimum value of 104 W when the lubricating oil temperature increased from 40 ℃ to 110 ℃ .The friction power loss in‐creased beyond 110 ℃ and increased to 140 W at 150 ℃ and the lubrication condition deteriorated sharply .The crankshaft fric‐tion power decreased by 10W when the inlet pressure of main oil passage increased from 0 .31 MPa to 0 .4 MPa and the decrease would be greater at low lubricating oil temperature .In addition ,the crankshaft friction power increased with the increase of ki‐nematic viscosity and its influence would increase at low temperature .%以某直列3缸汽油机为研究对象，利用 AVL EXCITE 软件建立了曲轴多体动力学仿真模型，通过台架试验，验证了该仿真模型的正确性，在此模型基础上分析了润滑油温度、供油压力以及润滑油种类对发动机曲轴摩擦功的影响规律。研究表明：指定条件下的曲轴摩擦损失功率仿真结果为106．6 W ，台架试验结果为102 W ，误差在5％以内，表明仿真模型具有相当的精度；当润滑油供油温度从40℃升高到110℃时，曲轴摩擦损失功率减小到最低，约为104 W ，当温度超过110℃后，摩擦损失增加，当温度上升到150℃时，摩擦损失功率达到140 W ，润滑条件急剧恶化；当轴承主油道入口压力从0．31 MPa 增加到0．4 MPa 时，曲轴摩擦功率减小约10 W ，且供油温度较低时润滑油供油压力对曲轴摩擦功率影响较大；曲轴摩擦功率随黏度的提高而增加，供油温度较低时，润滑油黏度对曲轴摩擦功率的影响较大。