Cnc Machine Tool Thermal Error Compensation Techniques

During the machining process, the components of the NC machining center are brought about temperature rise and thermal deformation, due to the heat sources, such as friction, coolant and ambient temperature, etc. The correct position between tool and work piece is destroyed, and thermal error of work piece comes into being. Thermal error of the NC machining center has been the main source error in precision and extra-precision machining process.With the intention of analysis the cause of thermal error and establishing the compensation model of thermal error, the detection experiments of thermal error are designed purposefully to study the rule and form the compensation method of thermal error. The main content of the text is to study the optimal layout of temperature measuring points on the compensation model of thermal error and establish the model of thermal error. On the basis of the analysis of causes and mechanisms on thermal deformation of the NC machining center, introduced the theory of temperature sensor layout and the theory of fuzzy cluster analysis and multiple linear regression modeling. The compensation model is established through the method of multiple linear regressions. This paper consists of the following five parts:1) Describes the background and significance of the study subjects are presented in detail at home and abroad Thermal Error Compensation Technology Research to illustrate the subject of this study's main focus.2) On the thermal error causes, the main method to reduce thermal error and thermal error compensation technology has done a brief description. Analysis of thermal error compensation methods for the error to avoid law and error compensation law, the strengths and weaknesses identified in this paper by comparing the thermal error compensation for the error compensation method will be taken; also compared the thermal error modeling is now a way to determine this Papers will be used to establish compensation for multiple linear regression model.3) Major study of the NC machine tool thermal distortion of the key technologies: the choice of temperature points, and thermal error modeling. The use of fuzzy clustering and correlation analysis to identify key points of temperature measurement, introduced the theory of multiple linear regression, and using the theory of error modeling theoretical study 4) Analysis on designing feature and thermal source of three-axle horizontal machining centre of subject investigated, then advance an experimental program of optimal layout of temperature measuring points on the compensation model of thermal error,and adopt the five-point-method to measure thermo mechanical error.5) The theory of multiple linear regressions is introduced. The compensation model of thermal error is established according to the different scheme of selecting temperature measuring points. At the same time the hypothesis of multiple linear and compensation targets of model are verified. In conclusion put forward the method of thermal error compensation on machine tool.