表面涂层改善柴油机喷油嘴抗磨性能的研究

Research on Wear Resistance Improvement of Diesel Nozzles Applied Surface Coating

提出在针阀的密封锥面上喷涂表面涂层来提高喷油嘴抗磨损性能的方案。根据喷油嘴的材料性能要求,选出Al2O3和DLC 2种代表性的表面涂层材料,利用ANSYS仿真分析喷涂2种涂层后喷油嘴的接触应力分布。结果表明,2种涂层材料显著提高了针阀密封锥面的强度、硬度和许用应力,针阀密封锥面承受冲击能力增强,其中DLC涂层对针阀偶件的保护作用更好;随着针阀密封锥面涂层厚度的增大,针阀偶件的最大接触应力减小,应力集中区域减小并向涂层上转移。通过发动机实验测试喷涂DLC涂层的针阀偶件的抗磨损性能。结果表明,DLC涂层针阀抗磨损性能明显好于无涂层针阀。

A method was put forward to improve the wear resistance performance of nozzle by spraying surface coating on the sealing cone of needle. Based on the material requirement of nozzle,Al2O3 and DLC were selected as two kinds of representative surface coating. The contact stress distribution of diesel nozzles applied these two coating were analyzed using software ANSYS. The results show that strength,hardness,allowable stress and impact resistance of the needle'sealing cone are significantly improved by Al_2O_3 and DLC coatings,and DLC coating has better protective effect on needle couples. With the increasing of coating thickness sprayed on the sealing cone of needle,the maximum contact stress of needle couples is reduced,the stress concentration is decreased and is transfered to the coating. Engine test was conducted to check the wear resistance of needle couples sprayed DLC coating. The results indicate that the wear resistance performance of needle is indeed enhanced after adding DLC coating.