MONITORING METHOD OF MAIN SHAFT ROTATIONAL SPEED IN MACHINE TOOL, MONITORING DEVICE, AND MACHINE TOOL

摘要

PROBLEM TO BE SOLVED: To make it possible to easily select a preset value for fluctuating the rotational speed of a main shaft, and find out an optimum processing condition for suppressing chatter vibration of the main shaft.SOLUTION: In a monitoring device, a graph showing the relationship between the fluctuation amplitude and the fluctuation period of rotational speed of a motor is displayed on a monitor of a fluctuation value setting part. On this graph, a current fluctuation position (first point) is indicated by a black circle marker, and also, a power limit line L of a motor fluctuation period is created based on a predetermined equation and depicted on the graph. In a range not exceeding the power limit line L, a new fluctuation position (second point) having a larger fluctuation amplitude and a shorter fluctuation period than the current fluctuation position is calculated and indicated with an arrow A guiding this changing from the current fluctuation position.