Study On Theory And Experiment About A New Type Intellectualized Straightening Process Unit

In this paper, the basic theory and method about plastic deformation straightening technology of shafts together with the automatic straightening processing technology are studied and discussed.A method for straightening named variable constraint three points bending is proposed, and the technological process and the straightening mechanism based on the method proposed are analyzed and calculated by nonlinear finite element method. The results of calculation show that higher precision can be gained through once loading while the magnitude and the application mode of loading are reasonable. Meanwhile, a conclusion also can be reached that the number of application nodes must be chosen properly, if not, obvious elastic region can occur when there are too many nodes, and local plasticity can appear while there are few nodes.The structural model of a new low cost horizontal automatic straightener with four pillars is proposed in the basis of analyzing and referencing existing research and technology about automatic straightener, and a principle prototype with simple structure, handling ease and easy guaranteed precision is deigned and fabricated. The prototype can straighten longer parts through lengthening pillars, changing the state of automatic straightener only suitable to straighten micromidi parts. Whereas, the existing automatic straightener which is gate type or C type can only straighten micromidi shafts in restraint of the length of work top.An error model about axial line of parts and flexural deflection of pillar is established according to concrete structure of the prototype, and the detecting principle of flexural deflection, motion control of loading mechanism and error compensation process are analyzed. Moreover, the automatic control system of the prototype is developed including hardware platform and all software based on demand analysis and ergonomical principle. So the automation of parts measurement and straightening process are realized. The hardware and software of the control system can be implanted in products.Intelligent control method in straightening process is also researched,a two-dimensional fuzzy controller with self-learning function is designed to promote efficiency and precision of straightening process. Inputs of the controller are amount of plastic deformation and its variance, and output is loading course. A parameter self-learning algorithm is presented after defining data structure and variable array to improve the prototype's adaptability to different size of workpieces.At last, lots of straightening processing experiments are done on the prototype, and experimental results proof effectiveness of the processing method and the control algorithm proposed in the paper. Experiment data show that the higher straightening precision can be reached by three to five loading for most of workpieces. However, the prototype is stable and reliable so that products can be fabricated based on the prototype.