A Study On Tube Inversion Forming Technology

Tube inversion is a special forming processing that was developed from traditional tube processing, such as flange in stamping, flaring and necking. Tube inversion has many advantages, it's simple and low cost. It even can make some complicated parts which are difficult to be manufactured by any other stamping technology. At the same time,forming performance is not very good. Some inactivation forms,such as axial destabilization in compression and end tearing destabilization,may happen during the forming process. Forming with conical die and fillet die has a special condition of dieless constrained and free forming,so the forming part has low dimension accuracy. Toward this situation,an investigation on tube inversion forming has been carried on by using the numerical simulation technology.First, based on lots of reference,this dissertation introduces the basic theories of tube inversion forming,features of many common tube inversion die, failure forms of tube inversion and simply analyzes two common failure forms axial destabilization in compression and end tearing destabilization.Second, further study has been carried out toward forming with conical die, fillet die and channel die. Forming process of above tube inversion dies has been discussed. The influence law of some main parameters in forming process has been obtained by analyzing these parameters'impact to forming process.Based on the study above,for the defects of traditional process, an aid-push die has been proposed and numerical simulation of its forming process has been done. Then some influence law of the parameters has been achieved. Compared with other common die, aid-push die improves the dimension accuracy of the components and the forming performance of tube stock.The achievement in this dissertation will play an important part in development of tube inversion forming technology and enlarging the application of this technology.