Thermal displacement correction device and thermal displacement correction method for machine tool

Abstract

The invention provides a thermal displacement correction device and a thermal displacement correction method for a machine tool. In thermal displacement correction of a machine tool, the accuracy of thermal displacement correction is improved by effectively learning the relationship between temperature and displacement. The thermal displacement correction device is provided with: a temperature sensor for measuring the temperature of each part; a thermal displacement estimation unit that estimates a thermal displacement correction amount on the basis of a preset thermal displacement estimation formula; a position control device that corrects the shaft command value on the basis of the thermal displacement correction amount; a displacement measurement device that measures the corrected displacement of the shaft command value; a thermal displacement correction learning data recording unit that records temperature information and displacement information when the displacement is measured; a thermal displacement correction learning unit that determines a thermal displacement estimation formula on the basis of the recorded temperature information and displacement information; and a displacement measurement timing diagnosis unit that compares the recorded temperature information at the time of past displacement measurement with the current temperature information at a predetermined diagnosis timing, and determines whether or not to measure the displacement by means of the displacement measurement device.

Description

technical field [0001] The present invention relates to an apparatus and method for improving the accuracy of thermal displacement correction by effectively learning the relationship between temperature and displacement in thermal displacement correction of a machine tool that estimates thermal displacement based on temperature information. Background technique [0002] When a machine tool is used for machining, various parts of the machine tool may be thermally deformed due to mechanical heat such as the operation of the spindle and feed axis, temperature changes in the machine tool installation environment, and coolant temperature changes. Such thermal displacement changes the relative positions of the tool and the workpiece, and therefore, when the machine tool is thermally displaced during the machining process, the machining accuracy of the workpiece is degraded. [0003] As a method of suppressing the thermal displacement of the machine tool, the following thermal disp...

AI Technical Summary

Problems solved by technology

However, in machine learning, in general, high accuracy can be obtained for learned data, but for unlearned data, it is easy to cause the problem of over-learning with large errors.

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