The Bending Quality Control Of The Thin-walled Rectangular Metal Pipe

The cold bending of metal pipe is an important part of tube plastic forming.After bending the metal pipe has many excellent performances such as light weight,shock absorption and large transmitter turn volume.In the modern technology it is widely used in the transmission of general industry gas and liquid.Many times it's also used as a mechanical structure in cars,aerospace flights and some other advanced machines.So more and more attentions have be paid in the study of metal pipe bending.After took a pipe bending the pipe will spring back,wrinkle,distortion,thickness reducing and crack of the pipe wall.With the popularization and application of the special material pipe and pipe with different cross section,big caliber,minor bend radius and thin walled.Above defects get serious increasingly.So it's necessary to get more and more worker to thrash out.In this paper it composite multi-subject knowledge such as metal material science,non-linear mechanics,mold design and optimized analysis method.On the base of processing requirement take an analysis of the metal pipe.Set the common engineering constructional steel as a study object and research its pipe bending simulation modeling technology.Obtain the distribution regularities of equivalent stress and strain in the formed pipe by the means of three-dimensional finite element simulation technique.And then study the influence of construction of the mould and technological parameters to final formed metal pipe.The main study content in this paper is as follows:1.Design a relevant three-dimensional finite element numerical simulation analytical model according the actual cold bending of the cylindrical metal pipe.Contrast the result of the display dynamic analysis with actual process product to verify the reasonability and reliability of the modeling and analytical method.2.Design a three-dimensional finite element numerical simulation analytical model in the finite element software for the size and structure of rectangle cross section thin-walled metal pipe that is given.Through the display dynamic analysis simulation we can get a numerical forming process and result.Then analysis the main forming defect—section distortion systematically.3.In this paper in order to improve the bending quality and reduce the section distortion the writer come up with a new method—change the core structure.According the general core structure and refer to related articles the writer design a new type core-Achimedean spiral core.Through the simulated result we can see the level of the section distortion is decrease obviously.After change the core the writer take a orthogonal optimization in technological parameters which are affect section distortion directly for work out a optimized bending verification.4.Manufacturing a bending die based on the optimization simulation models.And then take a verification test contrast by the test data with simulation results.