加装气浮飞刀铣削装置的车床改造及应用

Transformation and Application of the Lathe with Fly-cutter Milling Equipment

为了实现细轴上微小平面的精密加工,研制了一套飞刀铣削装置,该装置的主轴采用空气静压轴承,回转精度为0.1μm。将其加装在精密数控车床的工作台上,配合成组车削刀具,使工件能在一次装夹过程中,按照数控指令实现车削轮廓及飞刀铣削出微小平面,从而提高微小平面的加工精度。研究了气浮飞刀切削速度、背吃刀量和进给量等主要切削参数对微小平面表面粗糙度的影响规律。在0.4mm×0.4mm范围内的平面,其尺寸和位置精度±2μm,平面度小于1μm,表面粗糙度值达Ra0.03μm。

A fly-cutter with an air-bearing spindle to mill precision micro- flats on tiny parts has been developed, and the spindle error motion of which is 0.1 μm. The fly-cutter is mounted on the cross feed of a precision CNC lathe on which gang turning tools are used to turn tiny parts. As a result, turning tiny parts and milling micro-flats on these tiny parts are able to completed without the post-machining operation under numerical control, so as to make an improvement on the positioning precision of micro-flats. The relation between surface roughness of micro-flats on tiny parts and main cutting parameters, feed, depth of cut and speed of the spindle, is investigated. Tolerance and positioning precision, flatness and surface roughness in milled micro-flat sections typically 0.4 mm long and 0.4 mm wide in the side of turned tiny parts are ±2μm, less than 1μm and Ra0.03μm, respectively.