曲面微细铣削让刀误差预测与补偿

发布时间：2018-07-01 17:06

本文选题：微径球头刀 + 微细铣削力　；参考：《华中科技大学》2015年硕士论文

【摘要】：在曲面微细铣削加工过程中,刀具由于受到切削力作用产生变形,导致让刀误差的产生。让刀误差的存在使工件精度降低,对工件性能产生影响。研究曲面微细铣削加工中的让刀误差,有助于对其进行更好地控制,提高曲面铣削的精度。搭建了三轴超精密铣削实验平台,各轴采用直线电机驱动,并配有高速电主轴。对实验平台空间几何误差进行了补偿,进一步提升了平台精度。在对切削刃曲线进行数学描述的基础上,建立了考虑刀具偏心影响的瞬时切厚计算模型,通过直接测量的方式获取了刀具偏心参数。采用Z-Map法对曲面微细铣削过程中复杂的切触环境进行求解,获取参与切削微元的分布。最终建立了考虑刀具偏心影响等因素的曲面微细铣削力预测模型。在微径球头铣刀静刚度模型的基础上,建立了考虑变形反馈的让刀误差模型。将刀具的空间形变投影到理想切触点法平面内,对刀具变形和切削力进行迭代运算,求解得到平衡状态下的让刀误差。该模型与未考虑变形反馈的模型相比,具有更高的预测精度。让刀误差补偿后,刀具处于平衡状态下的切削条件可以直接从补偿前的理想刀位点处提取。使用刀具位于理想刀位点处的名义切削条件求取平衡状态下的刀具变形,建立了基于切削力平衡的让刀误差补偿模型。不同于双层迭代让刀误差补偿模型,基于切削力平衡的让刀误差补偿模型的求解过程不依赖让刀误差预测模型,避免了耗时的迭代运算,求解效率有较大提升。
[Abstract]:In the process of surface micro milling, the tool error is caused by the deformation of the cutting force. The existence of the tool error reduces the precision of the workpiece and influences the performance of the workpiece. It is helpful to control the cutter error in the micro milling of the surface and to improve the precision of the surface milling. The three axis ultra precision milling experiment platform was built, each axis was driven by linear motor and equipped with high speed motorized spindle. The spatial geometric error of the experimental platform was compensated, and the accuracy of the platform was further improved. On the basis of the mathematical description of the cutting edge curve, the instantaneous thickness calculation model with the influence of the tool eccentricity was established. The tool eccentricity parameters are obtained by the method of measurement. The Z-Map method is used to solve the complex cutting environment in the micro milling process and obtain the distribution of the involved cutting microelements. Finally, a micro milling force prediction model with the factors of cutting tool eccentricity is established. On the basis of the static stiffness model of the micro diameter ball end milling cutter, the model of the micro milling force is established. The tool error model is considered in consideration of the deformation feedback. The tool space deformation is projected into the ideal tangent contact plane, the tool deformation and the cutting force are iterated, and the cutter error is solved in the equilibrium state. The model has a higher prediction accuracy compared with the model without considering the deformation feedback. The cutting conditions in the equilibrium state can be extracted directly from the ideal knife site before the compensation. Using the nominal cutting conditions at the ideal knife site, the cutting tool deformation is obtained at the ideal knife site. The cutter error compensation model based on the cutting force balance is established. The cutter error compensation model is iterated by the different Yu Shuang layers, based on the cutting. The process of solving the error compensation model with force balance does not depend on the prediction model of cutter error. It avoids time-consuming iterative computation and improves the efficiency of the solution.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG54

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