三轴数控侧铣空间刀具半径补偿算法

TOOL RADIUS COMPENSATION ALGORITHM FOR THREE-AXIS NC PERIPHERAL MILLING

通过深入分析三轴数控侧铣加工的特点,利用几何平面投影原理,采用平面轮廓刀具半径补偿算法推导的类似方法,建立三轴数控侧铣加工的空间刀具半径补偿算法。将三轴数控侧铣加工的空间刀具半径补偿归纳为三种转接过渡类型处理,通过加工平面的投影相交求出空间两相邻程序段的过渡转接点坐标分量x、y,然后通过逆投影计算转接点的第三分量z,从而推导出各类型转接点的坐标计算公式。基于UG平台编写了三轴数控侧铣刀具补偿仿真软件,模拟和铣削加工实例结果表明所建立的三轴数控侧铣加工空间刀具半径补偿算法正确有效。基于该算法的空间刀具半径补偿G指令将可避免由于刀具磨损和刀具更换导致的三轴侧铣数控代码重生成。

By thoroughly analyzing the characteristic of three-axis NC peripheral milling, based on geometry planar projection, a tool radius compensation algorithm for three-axis NC peripheral milling is established by using the similar method to that for planar contours NC milling. The space tool radius compensation for three-axis NC peripheral milling is reduced to three types of transitions processing. The ftrst work is to calculate the coordinates （x and y） dimension of the transitions between neighbor linear segments in space by the projections intersection on the work plane, and the next work is to obtain the third coordinate（z） dimension of the transitions by reverse projection, consequently the formulas to calculate all sorts of transitions coordinates are derived. Based on UG platform, the simulation software of tool compensation for three-axis NC peripheral milling is programmed, the results of the simulation and NC milling examples show that the proposed space tool radius compensation algorithm for three-axis NC peripheral milling is highly effective and correct. The space tool radius offset G instructions with the developed approach will avoid NC codes regeneration due to tool wear or tool change during the three-axis NC flank milling process.