五轴数控后置处理算法研究与球头铣刀刃磨轨迹优化设计

A Post-processing Algorithm of 5-axis CNC Machine and Optimal Design for Ball-end Milling Tool's Grinding Path

提出了五轴数控机床后置处理算法的通用公式,并以正交AC型双转台机床为例进行了具体分析。以球头铣刀后刀面的刃磨为具体加工实例,在验证后置处理算法的同时,提出了"假想砂轮"的处理方法,在机床具体运动结构的限制下初步优化了加工路径。针对AC型双转台机床的C轴在奇异区域内存在转角步距较大从而形成过大的非线性误差并因此造成工件过切和机床震颤等的情况,提出在奇异区域内对加工路径进行三次B样条拟合后再插补的平滑处理方法,进一步优化了加工路径。仿真结果和实际加工效果都验证了此方法的可行性。

A universal post-processing algorithm for 5-axis CNC machine was proposed and applied to an orthogonal AC-type double turret machine.In this paper,experiments on the flank face grinding of a ball-end milling tool was conducted in the AC-type double turret machine.After verifying the post-processing algorithm,a″virtual grinding wheel″method was put forward to optimize the machining path roughly under the machine′s moving structural constraints.Considering the fact that the steps of C-axis rotate and cause big non-linear errors and overcut of the workpiece in the singularity region,which is normal in machine tools with a C-axis,the machining path in this region was optimized further with the cubic B-spline curve fitting method.The simulation and eventual grinding results verify the feasibility of this method.