Patent ID: 6029098
Filing Date: 2000-02-22
Classification: G05B,Y10T

Abstract:
A numerical controller for controlling a machine tool that feeds a tool in an axial direction of a spindle synchronously with a rotation of the spindle for machining a work piece, said numerical controller comprising:an input unit for inputting machining instructions specifying an axial feed speed pattern and including an axial feed distance of the spindle, and for setting system parameters including a time for ensuring that an axial feed speed of the spindle remains constant;an analyzing unit for determining a minimum feed distance necessary for machining based on said machining instructions and said system parameters, and for comparing said axial feed distance included in said machine instructions with the minimum feed distance, said analyzing unit comprising a calculating means for determining the minimum axial feed distance by calculating an axial feed distance based on the axial feed speed pattern in which the tool is accelerated at an acceleration a to a specified axial feed speed F.sub.c, the specified axial feed speed F.sub.c is maintained for a constant speed time T, and the tool is decelerated at a deceleration -a;a speed pattern adjusting unit for changing the axial feed speed pattern specified by the machining instructions to an adjusted axial feed speed pattern having a constant speed time longer than said time for ensuring that the axial feed speed of the spindle remains constant based on a result of said comparison made by the analyzing unit;a distributing unit for calculating and outputting driving instructions according to said adjusted axial feed speed pattern generated by said speed pattern adjusting unit based on the result of said comparison made by the analyzing unit; anda drive control unit for controlling a driving unit based the driving instructions output by said distributing unit.