The Research On Quantitative Calculation Method Of Pivot Distance Of Press Straightening

In recent years, straightening technology plays a more and more important role in the mechanism industry, in order to increase production efficiency and reduce inferior products and rejected products. Influenced by rapidly growing of national economy, automatic straightening machine together with related researches also shows their great advantages. Automatic straightening machine is necessary for modern efficient mechanical production. However, few researches on straightening have referred to the influence of pivot distance quantitative calculation on straightening results. However pivot distance is one of the important parameters in the straightening process, there is no good quantitative calculation method on pivot distance, and rough definition of pivot distance can not meet requirements of automatic straightening machine. Therefore, this dissertation will deeply discusses the quantitative calculation method of pivot distance to get a better support on theory of automatic straightening machine.Firstly this dissertation introduces researches of press straightening, including theories, equipment research status, and focuses on this group’s F -δpress straightening model and its application conditions in recent years, and common researches on load, pivot distribution. In order to meet further research, the empirical equation and stimulated curve-fit equation are used to describe the approximation of the bending materials, and the dissertation discusses the feasibility of pivot distance adjustment. Empirical equation and stimulated curve-fit equation are basic for establishment of pivot distance models, which are getting curvature from equation. This dissertation focuses on that when empirical equation and stimulated curve-fit equation are used by rectangle section and round section steel material, respective pivot distance optimized models can be created. Optimized models are limited optimized research, which set pivot distance and reverse bending curvature as variables, set curvature equation as limited terms. In order to verify calculation method of pivot distance, this dissertation focuses on two kinds of pivot distance optimized models created from rectangle section, selects 3 samples to do straightening test, test results shows that pivot distance optimized models are correct and effective.Through the theoretical study, this dissertation presents a calculation method of pivot distance; finite element analysis shows that the method is correct and effective, make determination of pivot distance from qualitative analysis to quantitative calculation. Pivot distance optimized research and calculation can provide better theory support on press straightening study and automatic straightening machine.