硬质合金微型钻头固有频率研究及应用

Research and Application of Natural Frequency of Cemented Carbide Micro Drill

分别利用实验、模拟和计算三种方法对微型钻头的固有频率进行分析,制备了不同直径及长度的未加工螺旋槽棒料和已加工螺旋槽产品,进行固有频率测试并分析不同规格棒料、产品之间频率的差异。根据实验结果总结了微型钻头一阶固有频率的经验公式,与棒料的模拟频率进行对比。结果表明:实验、模拟、计算三种方法表现出较好的一致性,微型钻头的固有频率与直径和长度有较明显的对应关系。针对钻径≤0.4mm、长径比>20的微型钻头,在微型钻头入钻前用经验公式可以较快地计算出微型钻头的固有频率;模拟方法可以较准确地求得微型钻头的多阶固有频率,方便进行共振分析;微型钻头钻孔过程中固有频率随着钻削深度的增加逐渐增大。

The natural frequencies of the micro drill are analyzed by three methods:experiment,simulation and calculation.The natural frequencies of unground spiral flute bars and grinded spiral flute products with different diameters and lengths are tested.The frequency differences between bars and products with different specifications are analyzed.Based on the experimental results,the empirical formula for calculating the first order natural frequency of the micro drill bit is summarized and compared with the simulated frequency of the bar.The results show that the three methods of experiment,simulation and calculation shows good consistency.The natural frequency of micro drill has obvious corresponding relationship with its diameter and length.For micro drill bits with drill diameter of 0.4mm and below and length diameter ratio of more than 20,the empirical formula can be used to quickly determine the natural frequency of the micro drill bit before drilling.The simulation method can accurately obtain the multi-step natural frequency of the micro drill bit,which is convenient for common vibration analysis.The natural frequency of micro drill bit increases with the increase of drilling depth.