错齿BTA深孔振动钻削刀具系统径向减振特性研究

BTA深孔钻削刀具系统刚性差,加工过程极易发生多个方向的颤振,而刀具颤振对孔的加工精度和刀具的使用寿命具有重要影响。根据错齿BTA内排屑深孔钻刀具系统的特点,构建了深孔钻削过程刀具系统径向动力学模型,通过其特征方程研究了径向动力学特性。为了获得普通钻削与振动钻削条件下刀具系统径向振动的行为特征,将切削加工过程离散为满足状态方程连续条件的多个微小切削单元,并采用差分方程求解方法给出了普通钻削与振动钻削过程刀具径向振动位移的数值解。仿真和实验结果表明,所建立径向动力学模型的求解结果与实验结果相吻合,振动钻削对刀具系统径向振动具有较强的抑制效果,与普通钻削相比,孔加工圆度和表面粗糙度都有了明显改善。

Radial damping characteristics of a drilling tool system in BTA deep-hole vibration drilling

Because of the poor rigidity of a tool system of boring and trepanning association(BTA) deep hole drilling,machining processes are prone to chatter occuring in several directions,which has a significant impact on the machining accuracy of the hole and the service life of the tool.According to the tool system characteristics,the radial dynamic model for the BTA deep-hole drilling system in drilling process was established and its dynamic characteristics were further studied by using the characteristic equation.In order to obtain the behavior characteristics of the radial vibration of the tool system in condition of common drilling and vibration drilling,the cutting process was discretized into multiple tiny cutting units which meet the continuous condition of the state equation,and the radial vibration displacements of the cutting tool system were solved by the numerical method for difference equations.The simulation and experimental results show that the solutions of the established radial dynamics model are consistent with the experimental results.Vibration drilling has a strong restraining effect on the radial vibration of the tool system.Compared with the conventional drilling,the hole machining roundness and surface roughness are significantly improved.