Research On Constant-curvature Recurvation Straightening Mechanism Of Tubes And Bars

With the rapid development of economy, the demand of high precision tubes and bars in industrial and high-tech areas is rising sharply. However, because of the external force, the change of temperature and some other reasons, this material will produce bending and twisting defects during manufacturing, processing and transportation, and that will affect their usage. So it is necessary to eliminate those defects via the process of straightening in production, only these tubes and bars reach certain level of flatness and roundness, can they meet the requirements of usage.In order to improve the straightening accuracy, it is very necessary to strictly control the structural parameters and process parameters of straightening machine. As for the straightening of tubes and bars, the recurvation-curvature of straightening roller is the most important structural parameters, as it is not only the basis of generating roll shape, but the key to determine the straightening quality. Only with the most suitable process parameters of roll shape to design and manufacture straightening rollers, can the straightening of tubes and bars meet our requirement.In this article, the author does an in-depth analysis on the mechanism of constant-curvature recurvation straightening for tubes and bars. On the basis of previous studies, the author considers some factors such as elastic core which affect the straightening quality, and then puts forward a theory about the design of constant-curvature recurvation roll shape. Combining with the characteristics of bars and tubes, the author accurately calculates the optimum recurvation-curvature for the straightening rollers, and obtains the straightening accuracy that they can be achieved; besides, does some analysis about straightening accuracy influenced by parameters of straightening rollers. The author hopes that this article could provide some helpful basis for the design of roll shape.