Development And Application Of Serial NC Macro Instruction Of Typical Contour

With the continuous improvement of the performance requirements of industrial products, typical contour parts which containing quadratic curve are widely used,meanwhile the accuracy of typical contour parts is getting higher and higher, however the CNC machine tools generally do not have the non-circular quadratic curve interpolation function,so the straight line or arc segments are applied to approximate and fitting the non-circular quadratic curves,and realized through the macro instruction programming. The program of macro instruction programming is short,succinct and easy to modify.The accuracy of part is high with the use of macro instruction programming.Because the generality of the macro instruction programming is not strong,and the efficiency of manual programming is low, it causes that the macro instruction programming method is not widely used. How to effectively realize generality, efficiency and high accuracy is the eternal goal of macro instruction programming and NC machining. At present, there are still many problems in the development of macro instruction of quadratic curve typical contour, which are mainly expressed as the followings:the first one is that quadratic curve machining program mainly is for a curve in a particular kind of curve, and there is no uniform similar curve equation,machining macro instructions is not the same, which makes the quadratic curve interpolation of macro instruction programming has been greatly restricted,the second one is that the rough and finishing macro instructions of quadratic curve typical contour, generally are used to the specific contour of some parts programming, the program is not universal, there is still a lack of the serial and modular macro instructions, the third one is that the calculating and processing method is usually used to program quadratic curve interpolation macro instructions, because a lot of macro program is used to the error check, the cutting tool may have a pause in the process, and reduce the surface quality of the parts. There is still a lack of methods of calculating before processing for the similar quadratic curve interpolation macro instruction programming. Therefore, there is an urgent need to develop the quadratic curve interpolation unified macro instructions of first calculating after processing and checking the errors,and are extended to quadratic curve typical contour machining,it has important theoretical value and engineering significance to further improve the macro instruction of generality, efficiency and high precision.In this connection,the unified equation of conic curve is analyzed deeply,the approximate calculation method and error control principle of conic curve are studied, the uniform interpolation macro instructions of developed the conic curve of the first calculating after processing, checking error, automatic data conversion and automatic processing are developed, CNC turning and milling the typical curve profile serialmacro instructions are developed, which are verified by simulation and machining experiments.The main works in this thesis can be concluded as follows:1) A unified macro instruction programming method to realize the interpolation of conic curves and its G code instruction format definition method was analyzed. The method of the first calculating after processing, curve fitting,error checking calculation, coordinate conversion, automatic extracting data and other advanced means were studied, the programming method of nested procedures in macro program was explored,and the generality and efficiency of the macro instruction was further enhanced, and the processing precision was improved.2) A method of serial macro instruction programming to typical contour was studied.The programming method of WHILE loop nesting was analyzed.The method of serial and modular NC milling universal macro instruction programming was designed.And the programming method of the embedded NC turning cycle instructions by the interpolation of the quadratic curve of the same kind is explored.The NC turning of the typical profile of the two curves was realized. It provides a reference for the improvement of the efficiency of macro instruction programming and the general improvement of the macro instruction.3) The unified macro instruction programming method for conic curve interpolation and NC turning and milling programming method for typical contour series macro instruction were analyzed based on the basis of the above research. The tool path and physical simulation were verified by the VERICUT simulation software and machine tool processing experiment.It was found that the operating procedures were normal, instructions were effective, machining accuracy was high.In summary, the researches in this paper make the macro instruction programming of typical profile get more generality, serial and efficiency, and machining accuracy is getting higher.