Study On Thermal Deformation Analysis And Modeling Of CNC Grinding Machine Tool

Worm wheel grinding machine tool is precision equipment for gear process. As the development of navigation, vehicle, energy, and war industry, further increases in demand for large and high-precision machine tool equipment, especially for high-efficiency grinding machine tool. Due to lack of mature thermal error model method, leads to hard to control thermal error compensation. Based on YW7232 worm wheel grinding machine tool, this paper studies on thermal error theoretical modal to compensate thermal error, realizing high precision machining.Main content and study method is as following.(1) according on thermal theory of worm wheel grinding machine tool and process parameters, set up 3D model of YW7232 worm wheel grinding machine tool; simulate the process of worm wheel grinding machine via professional analysis software DIAdem of NI; find out temperature field change law of worm wheel grinding machine, which provides a good theoretical basis for the subsequent theoretical model. Simplify establishing thermal error theoretical model and measuring points in thermal measurement test. Use mechanics of materials theory and correlation theory, analyze worm wheel grinding machine after thermal deformation and establish thermal error theoretical model.(2) Combined temperature flied change law, using fuzzy clustering and relevance analysis etc. method, analyze the key point in machine tools of thermal deformation and determine measuring point location. According to demand of thermal error measurement, set up software and hardware system of thermal error measurement and program humancomputer interaction interface of measuring software. Have experiment in a certain Chongqing corporation in practice processing. Select and analyze the large amount data measured via professional data analysis software DIAdem of NI, and plot its temperature curves which makes experiment direct and convenient and provides a good theoretical basis for the subsequent prediction model.(3) Adjust weights in traditional BP neural network through genetic algorithm. After normative approach initial data, establish thermal error prediction model of worm wheel grinding machine tools based on GA-BP through GOAT toolbox in MATLAB. Calculate theoretical error value and prediction error value through initial data measured and plot its thermal error figure. Contract analyzes thermal error figures of two models, which certified the validity of theoretical error model and provides a good theoretical basis for the subsequent thermal error compensation.(4) Propose a thermal error compensation method based on virtual axis that is adding a virtual axis basis on natural shafts, converting thermal error compensation amount into the equivalent of virtual axis compensation according to synchronous relationship between each axis, and selecting thermal error compensation point in spline curve in grinding stock and compensating thermal error via operating subprogram with compensation. Have thermal error compensation experiment on YW7232 worm wheel grinding machine tool, verify gear accuracy before and after compensation which validates the method is effective for thermal error. And the method is not only fit for thermal error compensation, but also suit for any error compensation. Due to conversion model changing as machine tool structure changing, it is of expansibility. Therefore, the method is suitable for any error on any machine tools which is shown that the method is with application values on error compensation technology.