Machine tool spindle thermal error optimum working condition determination method based on orthogonal test analysis

Abstract

The invention discloses a machine tool spindle thermal error optimum working condition determination method based on orthogonal test analysis. The method comprises the following steps: correlation coefficients between the temperature and the thermal deformation are determined to serve as thermal error evaluation indexes, the rotating speed, the time and the cooling or no cooling are selected as test design factors, and a level number of each factor is determined; an orthogonal table Ln(rm) according with fewer conditions is selected according to the level number of the factor, wherein L is a code name of the orthogonal table, n is a transverse row number of the orthogonal table, r is the factor level number, and m is a longitudinal line number of the orthogonal table; a spindle thermosensitive area is cut along a shaft tangent line to spread to form a rectangle, and measuring points are uniformly arranged in divided grids in the rectangular area; and each measuring point is tested in sequence to obtain correlation coefficients of the thermal errors of each measuring point according to the orthogonal arrangement of the measuring points, and the range analysis is performed to determine a thermal error test optimum working condition scheme. On the basis of reducing the test times, the method enables the tests to have the typicality and the tidiness comparability, and the working condition optimization and the arrangement point efficiency and reliability are realized.

Description

technical field [0001] The invention belongs to the field of thermal error analysis of machine tool spindles, and in particular relates to a method for determining optimal working conditions of machine tool spindle thermal errors based on orthogonal test analysis. Background technique [0002] With the rapid development of science and technology, precision and ultra-precision machining technology has become the most important component and development direction of modern machinery manufacturing, which requires higher and higher machining accuracy of CNC machine tools. According to relevant data, thermal error has become the main error source affecting the machining accuracy of machine tools, accounting for about 40%-70% of the total manufacturing error. Therefore, reducing the thermal error is very important to improve the machining accuracy of the machine tool. [0003] Since the thermal deformation error of a machine tool largely depends on various factors such as process...

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Problems solved by technology

In recent years, most of the thermal error test conditions are based on previous engineering experience or selected working conditions close to the processing site. However, due to the characteristics of thermal error, such as time-varying, multiple factors, and uncertain working conditions, the test conditions The model is not representative, and there are problems such as data redundancy and reduced stability

In this regard, Professor Yang Jianguo of Shanghai Jiaotong University and others proposed the regression positive The modeling method of cross-design, combined with factors such as machine tool mechanism, environmental conditions, engineering judgment, and many experiences to carry out thermal error modeling, well solved the problem of thermal error modeling in different environments, but it is not targeted Optimizing the design of working conditions has not seen the use of orthogonal experiments to optimize the optimal working conditions for thermal errors.

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