一种考虑对刀点的五轴数控机床几何精度预测方法  

A Prediction Method of Geometric Accuracy for Five-Axis CNC Machine Tools Considering Tool Setting Position

作　　者：邬昌军 郑明明 王巧花 范晋伟[2] 宋晓辉[3] 王良文 WU Changjun;ZHENG Mingming;WANG Qiaohua;FAN Jinwei;SONG Xiaohui;WANG Liangwen(Henan Key Lab.of Intelligent Manufacturing of Mechanical Equipment,Zhengzhou Univ.of Light Inst.,Zhengzhou 450002,China;Beijing Key Lab.of Advanced Manufacturing Technol.,Beijing Univ.of Technol.,Beijing 100124,China;Henan Academy of Sciences,Zhengzhou 450058,China)

机构地区：[1]郑州轻工业大学河南省机械装备智能制造重点实验室,河南郑州450002 [2]北京工业大学北京先进制造技术重点实验室,北京100124 [3]河南省科学院,河南郑州450058

出　　处：《工程科学与技术》2022年第4期173-186,共14页Advanced Engineering Sciences

基　　金：河南省科技攻关项目(212102210313,222102220010);河南省高等学校重点科研项目(21A460032,21A460034);国家自然科学基金项目(51775010,52075500)。

摘　　要：考虑对刀点对机床精度的影响,为对机床最终精度和性能进行评价,提出了一种考虑对刀点的五轴数控机床几何精度预测方法。该方法首先利用多体系统运动学理论,建立了基于NAS979斜置圆锥台的五轴数控机床运动方程。以此为基础,建立了基于对刀点的试件实际加工位置求解方程和数控加工指令求解方程,建立了五轴数控机床几何精度预测模型,预测了圆锥台圆度、同轴度和倾斜度等精度指标。然后,开展了五轴数控机床精度的仿真预测。圆锥台圆度、同轴度、倾斜度的预测值分别为0.029 mm、0.0654 mm、0.0243 mm,而圆锥台圆度、同轴度、倾斜度的标准公差要求值分别为0.100 mm、0.100 mm、0.030 mm。仿真结果表明,预测的圆锥台精度指标能够满足标准公差精度要求。最后,为了验证该方法的有效性性,开展了斜置圆锥台的切削实验验证。圆锥台圆度、同轴度和倾斜度的测量最大值分别为0.0380 mm、0.0931 mm和0.0282 mm,最小值分别为0.0316 mm、0.0658 mm和0.0246 mm,测量均值分别为0.0356 mm、0.0805 mm和0.0271 mm。实验结果表明,测量均值与预测值非常吻合。因此,在新研制的数控机床精度检验与验收过程中,机床研制单位能利用该方法准确、快速、直观地评估机床精度和性能。In view of the influence of tool setting position on the accuracy of a machine tool and the evaluation of its final accuracy and performance,a method of geometric accuracy prediction for a five axis CNC machine tool(FACMT)considering tool setting position is proposed.Firstly,the kinematics equation of the FACMT based on a NAS979 inclined cone frustum is established by using multi-body system theory.On this basis,the solving equations for the actual machining position and NC machining instructions of the test piece based on tool setting position are built,the prediction model of geometric accuracy for the FACMT is established and the accuracy indexes such as roundness,angularity and concentricity of the cone frustum are predicted.Then,the simulation prediction for accuracy of the FACMT is carried out.The predicted values of roundness,angularity and concentricity are 0.0251 mm,0.0573 mm and 0.0192 mm,respectively,while their required standard tolerances are 0.100 mm,0.100 mm and 0.030 mm,respectively.The simulation results show that the predicted accuracy indexes of the cone frustum can meet the requirements of standard tolerance accuracy.Finally,in order to verify the effectiveness of the method,the cutting experiment of the test piece of inclined cone frustum is carried out.The maximum values of roundness,angularity and concentricity are 0.0380 mm,0.0931 mm and 0.0282 mm,respectively,the minimum values are 0.0316 mm,0.0658 mm and 0.0246 mm,respectively,and the measured mean values are 0.0356 mm,0.0805 mm and 0.0271 mm,respectively.The experimental results show that the measured mean values are in good agreement with the pre-dicted ones.Therefore,in the process of precision inspection and acceptance of newly developed machine tools,this method can be used to evalu-ate their accuracy and performance accurately,quickly and intuitively.

关 键 词：对刀点 数控机床 几何精度 预测建模 圆锥台 

分 类 号：TG161[金属学及工艺—热处理]