车削大螺距外螺纹加工误差分布特性

Distribution Characteristics of Machining Error in Turning Large Pitch External Thread

采用轴向分层切削法车削大螺距外螺纹时,受机床主轴回转误差、刀具磨损和振动等因素的影响,螺纹面形成过程不稳定,其加工误差沿轴向分布具有多样性。利用误差最大值和最小值评判加工误差的方法,不能反映其分布水平和变化趋势。为此,依据螺纹面几何结构参数及其加工误差分析结果,进行两次车削螺纹试验,在左右螺纹面上选取多个特征点,利用其坐标值计算加工误差,构建中径误差和左右螺纹面大小径误差、牙型半角误差、螺距误差沿螺纹轴向分布行为序列,采用灰色关联分析方法,揭示和评价螺纹面加工误差沿轴向分布的特性。结果表明,采用上述方法可以定量评价螺纹面加工误差沿轴向分布的一致性。

When we turn large pitch external threads with axial layered cutting method, the formation process of thread surface is unstable due to the influence of spindle rotation error, tool wear and vibration, and the distribution of processing errors along the axis is diverse. The method for judging machining errors by maximum error and minimum error can not reflect the distribution level and change trend. Therefore, according to the analysis results of geometric structure parameters and machining errors of the thread surface, two turning threads tests were carried out. Several characteristic points are selected on the left and right threads surface, and machining errors are calculated by their coordinate values. Through the experiments,distributive behavioral sequence of big diameter error,small diameter error,half of thread angle error,pitch error and pitch diameter error of left and right thread surfaces are structured. Adopting the grey correlation analysis method, the characteristics of the error distribution along the axis of the thread surface are revealed and evaluated. The results show that the method can quantitatively evaluate the consistency of the error distribution along the axis of the thread surface.