基于宏程序的大螺距圆弧螺纹加工方法探讨

Discussion on Fitting Processing Method of Large Pitch Arc Thread Based on Macro Program

针对大螺距圆弧螺纹加工难度大、质量难保证的特点,探讨了大螺距圆弧螺纹的数控车削加工方法与编程思路。通过两种加工方法的对比提出采用拟合法(即分层切削深度逐渐减少的粗加工方法),选用较小的圆弧切削刀具,用宏程序编程去除加工余量;精加工采用拟合法(即沿螺纹轮廓线仿形车螺纹的方法)编写了采用单行程螺纹切削G32指令的圆弧螺纹加工通用宏程序。在FANUC数控车床上进行实践加工,验证了该宏程序加工方案的可靠性,较好地控制了圆弧螺纹的表面加工质量和表面粗糙度。该编程方法通用于梯形螺纹、异形螺纹等大螺距精密螺纹加工,在生产实践中具有一定的实际指导意义。

In view of the difficulty in machining and quality assurance of large pitch arc thread,the NC turning method and programming idea of large pitch arc thread are discussed.Through the comparison of two processing methods,a rough machining method of gradually reducing the depth of layered cutting by using fitting method is proposed.The smaller arc cutting tool is selected and the machining allowance is removed by macro programming strategy.The method of copying thread along the thread contour is adopted for finish machining.Finally,the circular arc thread machining tool with one-way thread cutting G32 instruction is compiled.The macro program is applied to FANUC CNC lathe to verify the reliability of the macro program,and the surface machining quality and surface roughness of arc thread are well controlled.This programming method can be used in the machining of trapezoidal thread,special-shaped thread and other large pitch precision thread.It has certain practical guiding significance in production practice.