Research On The Measurement Parameters Of Helicoidal Surface Based On Modeling Principle And Building Of VMS

The appearance of digital manufacturing technology has greatly promoted thedevelopment of manufacturing industry. High precision mechanical and electricalproducts emerge endlessly, which demands higher detection accuracy to theseproducts. At present, the research on virtual manufacturing technology has advanceda great deal, especially, in the area of NC machining simulation, which puts urgentlyforward requirements to the virtual measurement, the follow-up process of virtualmanufacturing.Helicoidal surface is a kind of complex surfaces, which has widelybeen used in the products of petrochemical industry, ship industry and aerospaceengineering. It has great significance to make deeper research on the virturalmeasurement of the helicoidal surface.The article aims at building up the virtualmeasurement system, through research on the measuring process of helicoidal surface,analyzing the machining process error sources, in order to forecast the machiningaccuracy and to improve the machining efficiency.Research on the characteristic parameters of helicoidal surface. From analysisof the forming principle of helicoidal surface, convert the measurement of thehelicoidal surfaces to that of the parameters of the contour curve on the end face, thetooth profile curve and spiral curve. Analyze the measuring principle and processthrough contact-measurement and contactless-measurement. Insight into themorphological features of the characteristic parameters of the contour curve on theend face, the tooth profile curve and spiral curve. And propose assessment methodsand formulas of corresponding errors.Research on the building of virtual measurement system. Study on the totalstructure design in the virtual measurement system of helicoidal surface. Present anovel simple and easy method of building up the virtual measurement system whichis comprised of functions designed by the idea of modulization, defining andindicating the concrete content and function of each module. Research thetechnological processing error sources, and build a model of mathematical relationship between the machining precision of workpiece, and errors of processingsystem and those of technological process procedure. And derive the model ofmathematical relationship between the measured quality characteristics and the errorsources for helical surfaceResearch on the algorithm of characteristic parameters and the techniques invirtual measurement system. With the analysis of the form features of helical surface,propose and derive a versatile mathematical model of helicoidal surface on theend-section profile and modeling method of “rotating overlap method”, realizing3Dmodels of both cylinder helicoidal surface and cone helicoidal surface withparameterization. According to the model of mathematical relationship between themeasured quality characteristics and the error sources for helical surface, themeasurands are added with discrete errors, and data covering error information thenare processed in accordance with assessment methods of errors, fulfilling the virtualmeasurement with the error values.