提高活塞燃烧室抗疲劳开裂性能的新途径

针对活塞燃烧室喉口开裂失效随着爆发压力提高有所增加的趋势,利用FEA技术并结合发动机耐久试验进行了异形销孔结构对燃烧室开裂影响的研究。除了热应力、材料蠕变等会引起喉口疲劳开裂外,发现活塞销孔结构对燃烧室开裂也有重要影响。异形孔结构可提高销孔承载能力,但同时提高了燃烧室边缘拉伸应力幅值,降低了顶部可靠性能,通过优化设计销孔结构可提高燃烧室及销孔承载能力。

The New Way of Improving Fatigue and Crack Resistance of Piston Combustion Chamber

The crack and failure of aperture of larynx of piston combustion chamber can lead to the increasing trend with explosive pressure increasing,use FEA technology and engine durability test to research the crack effect of combustion chamber with the irregular shape structure of piston pinhole.Heat stress and material creep deformation can lead to the fatigue and crack of aperture of larynx,besides the structure of piston pinhole has on important effect on the crack of combustion chamber.The structure of irregular pinhole may increase load-bearing capability of pinhole,but at the same time increase pull stress amplitude in combustion chamber edge and decrease the reliability of combustion chamber top,the optimum design of pinhole structure may increase load-bearing capability of pinhole and combustion chamber.