金刚石车削刀高误差下表面特征及力学表现

Surface characteristics and mechanical performance of diamond turning under tool height error

为探究工件中心刀具干涉的形成机理,实现刀高误差的在线辨识,围绕刀高误差存在情况下,刀具干涉的产生及加工过程参数的影响等方面展开研究.通过分别建立车削行程中工件中心圆台及刀具后刀面的三维形貌方程,基于两者间的位置关系推导刀具干涉区域半径的数学模型,探讨加工过程参数对刀具干涉区域三维形貌的影响.根据所推导的数学模型,利用刀具与工件挤压面积的投影来表征切削力的变化,建立刀高误差的预测模型.理论与试验研究结果表明,刀高误差、切削深度、刀尖半径及刀具后角直接影响刀具干涉区域的范围与形貌,工件刀高误差可通过监测切削行程中的切削力进行在线辨识.

In order to explore formation mechanism of the tool interference at the workpiece center and realize the online identification of tool height error,tool interference generation and the influence of the processing parameters were investigated under the condition of the tool height error.By establishing the equations of the three-dimensional(3D)topography of round platform and the tool clearance face respectively during the turning process,a mathematical model for calculating the radius of tool interference zone was derived based on the relationship between the two positions.Meanwhile,the influence of processing parameters on the 3D topography of the tool interference zone was discussed.According to the derived mathematical model,the cutting force was characterized by the projection of the extrusion area between tool and workpiece,whereby a prediction model for the tool height error was established.The theoretical and experimental results show that the tool height error,cutting depth,tool nose radius and tool clearance angle directly affect the range and shape of the tool interference zone.The tool height error can be identified online by monitoring cutting force during the turning process.