Cutting force detection method and machining control method and apparatus based on detected cutting force

Abstract

End-mill machining control method and apparatus in which cutting forces tangential and normal to tool motion are detected and machining is controlled based on the detected cutting force values. A primary component Ft and motion axis components Fx, Fy of a cutting force are determined from current values of a spindle motor and motion axis motors for tool feed. A cutting-engaged angle αen is determined from a radius R of a tool and a depth of cut I into a workpiece. A motion direction angle β is determined from distribution motion amounts ΔX, ΔY to the axes. The cutting forces Fm, Fs tangential and normal to tool motion are determined from the primary component Ft and a motion axis component Fx or Fy whichever is the largest, the cutting-engaged angle αen, the motion direction angle β. The accuracy of the determined cutting forces Fm, Fs is high since they are determined from the primary component Ft less affected by disturbance and the largest axis component of the cutting force. By controlling the cutting forces Fm, Fs tangential and normal to the tool motion, machining accuracy can be improved and tool life can be extended.