Experimental Study On On-Line Temperature Measurement Of High Speed Machining Process Of Difficult Machining Material

In the condition of high speed cutting, a large amount of cutting heat will be produced. The heat distribution of the tool chip area is an important factor affecting the life of the cutting tool and the surface quality of the workpiece. Especially in the wide use of hard machining materials today, the demand for cutting tools will be higher. Therefore, the research on the method of temperature measurement is not only helpful to study the mechanism of high speed machining, but also can be used to analyze and improve the service life and working reliability of the cutting tools. The thesis use the embedded temperature measurement handle designed by our laboratory to surface machining the Cr12 Mo V of difficult to machine material based on the natural thermocouple temperature measurement principle. According to the temperature data, the characteristics of temperature rise is analyzed, and provide theoretical basis and experimental data for path optimization. The main research contents are as follows:Firstly. The experimental select Cr12 MoV as the workpiece material, select the knob as a typical part. The three-dimensional modeling of the knob model is carried out by Pro/E, and converted into the file format which can be identified by MasterCam9.1. In the MasterCam9.1 set the relevant parameters, select the processing path, after the entity verify, generate NC file, complete the automatic programming model of the knob.Secondly. Orthogonal experiment of high speed milling is carried out, through the analysis of the experimental data, the characteristics of the overall temperature and the the local temperature are analyzed. According to the tool path diagram shows, the temperature curve peaks generally occur in large curvature and steering tool. At the microscopic level, the tool temperature rise is not stable, but the volatility like the process of jag. At the same time, the influence of cutting parameters on the cutting parameters is analyzed, According to the result, the influence of the milling speed on the temperature is more obvious the feed quality.Thirdly. Using genetic algorithm, taking the machining efficiency and cutting tool temperature as the optimization objective, Taking milling parameters as constraints to optimize. The objective function is optimize by the genetic algorithm toolbox of MATLAB, the optimal solution is obtained after the 51 convergence. The results are verified by experiments, the optimized cutting parameters can reduce the temperature of cutting tool and increase the removal rate.Finally. Analysis the tool path of the rough machining comes with the MasterCam9.1.To select the reciprocating line cutting, one way cutting and the equally spaced ring cutting as the optimization objective. According to the cutting path and simulation processing effect diagram, the three kinds of walking knife method are compared and verified, the advantages and disadvantages of three kinds of cutting tools in the temperature and efficiency are analyzed, and the advise about selection of cutter paths in the practical process is given.Through theoretical modeling and experimental study, the regular of cutting tools ' temperature rise in the numerical control machining process is found. As well as the influence of temperature rise on the cutter and the workpiece, and provide the basis for optimizing the NC machining parameters and cutting tool path.