Tool wear detection method based on current signal of CNC machine tool spindle servo motor

Abstract

The invention relates to a tool wear degree detection method based on numerically-controlled machine tool spindle servo motor current signals. The method solves the technical problem in the prior artthat the wear condition of tools on numerically-controlled machine tools cannot be managed effectively by means of manual operation. The method comprises the steps of first performing wavelet packet multi-threshold denoising treatment on working currents of a spindle servo motor and then performing wavelet decomposition to obtain 16 frequency band signals N1-16 in the range of [0, 500]Hz; reconstructing the wavelet decomposition coefficient and solving the coefficient xik of each node, wherein if the reconstruction signal amplitude of the node of each layer is expressed by S1-S16, the total amplitude S of current signals is the sum of the reconstruction signal amplitudes of the nodes of the layers; calculating the energy value E1-16 of the 16 frequency band signals; calculating the sum E_total of the energy of the 16 frequency band signals; calculating the percentages P1-16 the 16 frequency band signals account for in the energy sum E_total and taking the sum of the energy percentagesof the first two frequency bands (P1+P2) as the assessment indicator PX of the exceptional wear condition of tools. The method can be widely applied to the technical field of numerically-controlled machine tool wear degree detection.

Description

technical field [0001] The invention relates to the technical field of detecting the wear degree of a CNC machine tool, in particular to a method for detecting the wear degree of a tool based on a current signal of a servo motor of a spindle of a CNC machine tool. Background technique [0002] With the development of the domestic machinery industry, the annual output of CNC metal cutting machine tools in the country is stable at about 250,000 units per year. Under the existing extensive management of tools, tool life depends on manual statistics, which is time-consuming and laborious, and prone to errors; more than 30% The tool life is set to be redundant and wasted; there is no monitoring of tool wear and chipping, and the quality risk is high; there are many machining equipment, lack of unified monitoring, and the randomness is large; if the tool wear is higher than the blunt standard, If the tool is blunt or damaged, it will affect the machined surface quality and dimensi...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to solve the technical problem that the prior art cannot effectively manage the wear condition of the cutting tool on the CNC machine tool manually, and provides a current signal based on the servo motor current signal of the spindle of the CNC machine tool that can accurately and quickly monitor the wear condition of the tool. Tool wear detection method

Images