Thermal error predicating method for rolling ball screw feeding system of numerical-control machine tool

Abstract

The invention belongs to the technical field of thermal error predicating methods, and provides a thermal error predicating method for a rolling ball screw feeding system of a numerical-control machine tool. Thermal errors of the rolling ball screw feeding system are predicated through a self-adaptive real-time model (ARTM). The thermal error predicating method comprises the following steps of: firstly, establishing experiments for measuring temperature changes, along with time, of the surface of a workbench; secondly, establishing the self-adaptive real-time model for predicating transient temperature distribution and thermal error distribution of rolling ball screws; thirdly, determining a heating rate of two bearings, a movable nut and a slide rail of the rolling ball screw feeding system through a finite element combined monte carlo method (MC); fourthly, establishing an exponential equation of feeding speed and time according to finite element calculating data for describing and measuring temperature difference changes, along with time, between surface points and kinematic pair centers; and finally, establishing a numerical value predicating algorithm for predicating thermal errors of the rolling ball screw feeding system. Corresponding thermal errors are quickly predicated with high precision by the numerical value predicating algorithm in a mode of monitoring surface temperatures of two bearing bases and a motion nut side surface.

Description

technical field [0001] The invention belongs to the technical field of thermal error prediction methods, and relates to a thermal error modeling method for a ball screw feed system of a numerical control machine tool. Background technique [0002] The ball screw is a key component of the feed system of CNC machine tools. During operation, the frictional heat generated by bearings, screw nuts and other components causes the temperature of the screw to rise, and the change in temperature causes the deformation of the mechanical structure, thereby generating thermal errors and reducing the feed. system positioning accuracy. Due to the existence of thermal errors, the processing accuracy of a single piece is easily unqualified; the consistency of batch processed products is poor. Therefore, the problem of machine tool thermal error has been the focus of recent research at home and abroad, and has become an important research direction to improve the positioning accuracy of CNC ...

AI Technical Summary

Problems solved by technology

[0003] In recent years, researchers at home and abroad have established several effective methods for ball screw thermal error models, but they all have their limitations.

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