Method of controlling thread cutting

摘要

A method includes: (a) transferring a tool to where thread cutting is to start; (b) cutting threads in work with the tool; (c) performing tool deceleration along the Z-axis and acceleration along the X-axis during a predetermined acceleration/deceleration time Ta to retract the tool along the X-axis; and (d) returning the tool to a reference point. In Step (c), to shorten the incomplete thread portion, a command is issued concurrently with the start of the acceleration/deceleration time Ta to realize a pullout speed Ve along the X-axis that exceeds an allowable maximum speed Vmax to increase the acceleration along the X-axis. The speed command for moving the tool along the X-axis is maintained at the value of zero from the elapse of command time Te until the acceleration/deceleration time Ta expires to maintain the actual speed of the tool along the X-axis at or below the allowable maximum speed Vmax.