一种高频振动刀具的失效分析和优化

高频振动刀具在包装、鞋类等行业制样时使用广泛,由于转速较高,刀具在正常使用时常因噪声和加工精度达不到要求而失效。本文基于柔性多体动力学与有限元联合仿真的方法,建立了高频振动刀具的刚柔混合模型,通过仿真得出刀具失效是由于偏心轴套受力不均、连杆变形位移较大引起的结论,与实际使用过程中失效形式吻合,验证了联合仿真模型的有效性;对比分析了柔性连杆的自由模态和刀具工况约束下的模态,得到了避免发生共振的频率范围;利用动平衡方法对结构进行了改进设计,通过平衡机构部分惯性力有效提高了工作频率,为进一步进行结构优化奠定了理论基础。

FAILURE ANALYSIS AND OPTIMIZATION OF A HIGH FREQUENCY VIBRATION TOOL

The High-frequency vibration tool is widely used in the packaging, footwear and other industries to make samples. At high speed, the tool often fails to meet the requirements due to noise and inaccuracy. Based on flexible multi-body systems dynamics theory and combined finite element analysis simulation method, a rigid-flexible coupling model of the high frequency vibrating tool was developed. Several useful conclusions are drawn that the reasons for tool failure are uneven stress on the eccentric shaft sleeve and big deformation for the linkage coincided with the practical. It also verified the model accuracy. Meanwhile, the flexible rod free mode and the tool mode under the constraint were analyzed, the resonance vibration frequency was obtained. The structure was improved by dynamic balance method, which effectively increased the operating frequency by balancing a part of mechanism inertial force and laid a theoretical foundation for the tool advanced optimization.