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The application of pipe over the oil wells, oil and gas transportation, building structure, auto mechanics, transport and daily necessities of life and power plant boilers, condensers, heat exchangers, superheaters almost all pipe applications. With the development of these industries, promote rapid growth in demand for welded pipe welded pipe production has been greatly developed. Currently, the metal strip forming the tube main methods stamping France (Press) and the roller-type forming France (Roll). Stamping method is suitable for the production of many varieties, small quantities of short tube; roll-forming method is suitable for the production of large quantities of long tube. With the increasing demand for product features and diversification outside of manufacturing specification roll forming method under the long tube of the growing demand for stepper thin-walled tube forming method is based on the background forming a new, more variety, less bulk long tube as the main production object. The key to the molding of thin-walled tube is inhibited by the wrinkles generated by the warping and edge portions in the longitudinal direction generated in the forming process. The authors analyzed the the warpage and wrinkling Cause, when forming domain of the centerline of the sheet length and the edge line appearance, etc., and the length variation of the most hours, can inhibit the warping of the cylindrical tube and wrinkling assumptions. Under this assumption of the existing center bending method, edge bending, circumferential bending method and bending method to analyze and summarize selected the stepper tube forming method of forming the way - Edge bending method. Carried out in-depth research on the edge of the curved, forming analysis model is constructed, given the impact of tube forming the two key empirical formula of the curve (the centerline and the tangent point connection), systematic analysis of the formula, too the range of the function parameters. The tube centerline and edge line trajectory equation, according to the minimum principle, create a chart in Excel, draw the edge elongation graph using Excel for iterative solution, established two critical curves constructed from the geometry parameter m , n and K of the optimum value. According to the results of the theoretical analysis, UG mold design, the integrated form part of the mold the shear and the correction part, makes the mold more complete, more compact, smaller footprint, lower production costs. Analysis tryout proposed solution, perfect mold design to final production to meet the design requirements of the tube. Practice has proved that the assumptions made and the process of analysis is reasonable, the design of the mold meet the many varieties, small batch long tube production requirements.
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