A new spinning-extrusion forming technology for the inner-ribbed component

Abstract

To solve the problem that the rib filling height is low in the traditional spinning forming (TSF) of ribbed component, a new spinning-extrusion forming technology (SEF) was proposed. A convenient device was built to conduct the SEF experiment, whose results show that the new SEF can greatly increase the rib filling height by 53% compared with the TSF. Moreover, the improvement mechanism and prediction model of rib filling height in the SEF were investigated. It is found that the rib filling in SEF is mainly dependent on two deformation stages: tension-shear deformation, which makes the material accumulate and bulge above the rib groove; compression-shear deformation, which makes the accumulated material fill into the rib groove. The final rib filling height is linear dependent on the material bulge amount in the tension-shear deformation stage. And, the improvement of rib filling by SEF lies in it can enhance the duration and deformation amount of tension-shear deformation stage, thus improve the material bulge amount in contrast to the TSF. On these bases, taking the material bulge region in SEF as object, slab method was used to analyze its deformation mechanics and establish the differential mechanical equilibrium equations; Thamasett method was adapted to calculate the spinning force; synthetically, the material bulge amount was theoretically calculated. Then, combing the linear relation between the material bulge amount and rib filling height, the model for prediction of rib filling height in the SEF was developed. The predicted rib filling heights under various processing parameters indicate that the rib filling height can be improved by increasing the extrusion force, thickness reduction rate, feed ratio and roller attack angle in the SEF.