Research On The Forming Principle And Experiment Of Concave Camshaft Contour With CNC High-speed Grinding

Camshaft is very important part of automobile engine and other internalcombustion engines, their machining quality has a direct relationship with the overallperformance of the engine. Especially with the improvement of engine powerperformance and fuel emission standard, the concave structure is greatly used in thelift section of fuel supply system camshaft,that is the concave camshaft. Theemergence of concave contour makes camshaft grinding process more complicated.Therefore, the article aims to study concave camshaft CNC grinding, analyze thecomposite CNC form grinding process of the concave camshaft contour. For theconcave camshaft grinding, an innovative processing based on optimization of thecritical radius of grinding wheel is proposed, which provide a theoretical basis for theformulation of concave camshaft grinding process technology. This paper does theresearch work mainly includes:(1) It has analyzed typical CNC grinding process of camshaft as well as thecharacteristics of the concave camshaft grinding. Switch guidelines are given aboutlarge size and small size grinding wheels, and as a basis to guide the formulation andimplementation of the concave camshaft CNC composite grinding process to improvethe efficiency of the concave camshaft grinding.(2) Aiming to the original lift contains "noise" data, the paper proposed a"midpoint Rebound" method to pre-fairing it, and then use the cubic spline curveinterpolation and re-fitted the lift in order to achieve function of denoising. Byanalyzing the characteristics of concave camshaft contour,feature points of the outlineare extracted, and a new grinding process is proposed which is based on theoptimization of the critical radius of grinding wheel.(3) The reconstruction of concave contour and using the numerical controlgrinding automatic programming software to generate NC code were completed. Aplatform for high speed grinding experiments is built. Related comparativeexperiments based on experiment grinding test method and optimization of the criticalradius of grinding wheel are carried out on the CNC8325B Ultra-high speed CamshaftGrinder, the results show that the concave camshaft are completely meet theprocessing precision and requirement by using this new processing, it can make fulluse of the advantages of high efficiency grinding about the big grinding wheel. It also provide a favorable condition to achieve the high-efficiency and high-quality grindingfor the concave camshaft.