针对发动机活塞失效形式，结合活塞工作过程中所受应力的非均匀分布，以 XL-2V 型发动机为试验对象，将均匀排布的减阻耐磨型凹槽、凹坑结构优化变形为非均匀排布形式应用于活塞裙部。为了保证凹槽和通孔卸载活塞环槽集中应力作用的实现，同时使凹槽和通孔不影响活塞裙刚度以加大活塞裙底部变形，在发动机活塞裙部表面以环形形式逐行加工出变深度、变宽度、变间距的宏观凹槽及通孔形态，且槽深、槽宽、槽间距距离活塞顶部越近尺寸越大。运用正交试验方法制定了9种试验方案，选取3因素分别为孔槽分布类型、凹槽深度和凹槽宽度。搭建发动机冷试验台架，对9种凹槽形活塞和标准活塞进行对比试验，以磨损量和功率损耗率为试验结果指标。试验结果表明：凹槽形活塞磨损量平均减少35%、功率最大提高1%；凹槽形分布较其他2种分布类型减阻、耐磨效果更佳；较小的凹槽深宽设计更有助于保证活塞刚度、延长活塞寿命。%XL-2V type engine is used as the research subject. Failure modes of the engine piston and the stress of the working piston that is non-uniform distribution are considered. Many scientists developed the grooves and pits on the surface of kinematic pair, which were uniform distribution and friction reduction and wear-resisting. This paper optimizes the structures of grooves and pits, which are non-uniform distribution, for acclimatizing movement of engine piston. Grooves and through-holes surrounding the piston skirt of the engine is machined, which have variable-depth variable-width variable-separation. The sizes of depth, width and separation are bigger and closer to the top of piston to unload concentrated stress of piston ring grooves and keeping stiffness of piston skirt not to make enlargement deformation. With the orthogonal experiment method, nine test plans are made. The three experimental factors are hole and groove distribution pattern, groove depth, and groove width. Finally a cold test bench of engine is made and research 9 bionic pistons and standard piston are contrasted. Results show that abrasion loss of grooved pistons is redeced 35% and power is enhanced 1% ; “grooves distribution” is better than the other two distributions on friction reduction and wear-resisting; the smaller grooves' depth & width, the better piston's rigidity and the longer piston's lifetime are.
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