空气锤钎头齿孔过盈配合数值模拟研究

A numerical simulation study of the tooth-hole interference fit of the air hammer bit

传统方法在研究空气锤钎头齿孔过盈量问题时大都是针对单个齿孔进行的,而且对模型进行了过度简化,没有考虑钎头本体的复杂几何外形和相邻孔间应力的相互影响,无法得出整个钎头体上的应力分布。为此,分别用弹塑性力学方法和有限元方法对齿孔在不同过盈量下的应力分布情况进行了计算。结果表明,弹塑性分析与有限元分析结果一致,钎头中心齿齿孔过盈量取0.05～0.06mm、边齿齿孔过盈量取0.06～0.07mm时较合理,弹塑性力学方法的计算值比较保守,但仍有重要的参考价值。利用ANSYS软件对钎头齿孔过盈配合进行有限元计算,是改进齿孔设计的有效方法,此方法也可用来分析PDC钻头和牙轮钻头齿孔过盈配合问题。

The traditional research method on the problem of the tooth-hole interference magnitude of the air hammer bit focuses on a single tooth.Moreover,the model is over-simplified.It does not take into consideration the complex geometric contour of the bit’s body itself and the mutual effect of the stresses between the neighboring holes.The stress distribution of the whole bit body cannot be obtained.Therefore,the calculation of the stress distribution of the tooth holes under different interference magnitudes was conducted on the basis of the plasto-elastic method and the finite element method respectively.The result shows that the result obtained by the plasto-elastic analysis is in agreement with that by the finite element analysis.When the hole of the central tooth of the bit tooth-hole interference magnitude is set as between 0.05 mm and 0.06 mm and the hole of the lateral tooth as between 0.06 mm and 0.07 mm,it is reasonable,with a conservative elastic-plastic solution but still with an important reference.Adoption of the ANSYS software to make a finite element calculation of the bit tooth hole interference fit is an effective method to improve the tooth hole design.The method can also be used to analyze the tooth-hole interference fit of the PDC bit and cone bit.