The invention discloses a stepped
deep hole machining method and belongs to the field of
numerical control machining. When a stepped
deep hole is machined, a
small hole drill bit is bent under stress, torsion combined torque is large, the coaxiality of a drilled large hole and a drilled
small hole is poor, and the roughness of the inner wall face of a drilled hole is large. According to the
deep hole machining method, the deep hole is machined in a segmented mode on the front face and the back face, namely, a large-
diameter hole in one side of a workpiece is machined firstly, the workpiece is turned over and aligned, and then a small-
diameter hole in the other side of the workpiece is machined, so that on one hand, the length of the deep hole machining tool can be reduced, and the problem that in the deep hole
machining process, the machining precision is poor due to the fact that the machining tool is too long is solved; meanwhile, the coaxiality of the two deep holes can be ensured; and on the other hand, when the large-
diameter hole is machined firstly and then the small-diameter hole is machined, flowing of cooling liquid is facilitated, and therefore sufficient cooling and
chip removal of the workpiece are achieved. The method is mainly used for stepped deep hole machining.