Исследование утонения в местах изгиба и изменение ширины исходной заготовки

Abstract

Установлено, что утонение, возникающее в местах изгиба тонкостенных гнутых профилей, увеличивает расчётную ширину заготовки и в ряде случаев, особенно при формовке тонкостенных профилей с элементами двойной толщины сложной конфигурации может приводить к искажению их формы. Проведены теоретические исследования величины утонения в местах изгиба гнутых профилей, получена формула для определения приращения ширины в каждом месте изгиба, которой следует пользоваться при проектировании технологии и выборе ширины заготовки при освоении новых профилей.When the forming rolls in roll forming mill in the field of bending metal necking occurs, causing a change in bandwidth during its deformation. Therefore, if we ignore this increase in width of the workpiece, during the development of the production of new profiles situation aris es technology, when its width is larger than the estimated width of the roll caliber varying mill, which in some cases can lead to the formation of profile defects flatness its individual elements. The perspective gage of profiles of a difficult configuration with elements of double thickness is analyzed. It is set that the weight of 1 running meter of bent profiles, and, therefore, their thickness, permanently decrease. Now, in a gage there are profiles 0,5 mm thick and less. It, causes a row of the additional difficulties connected to receiving qualitative thin-walled profiles, in particular, owing to change of thickness of a preformed band from thin-sheet material, origin of nonplanarity on separate sections of profiles is possible. It is set that t hinning of sheet metall, arising up in the places of bend of the thin-walled bent types, increases the calculation width of purveyance and in a number of cases, especially at roll forming of the thin-walled types with the elements of double thickness of the complicated configuration can result in distortion of their form. Theoretical researches of size of t hinning in the places of bend of the bent types are conducted, a formula is got for determination of increase of width in every place of bend, which it is necessary to use at planning of technology and and choice of width of purveyance at mastering of new types.