Study On Precision Forming Technology Of Roll Forming And Rotary Draw Bending Of Commercial Vehicle Anti-collision Beam

In recent years,the automobile industry has developed rapidly and healthily,and the roll forming process has become increasingly widely used in the automotive field in our country.For example,commercial vehicle anti-collision beams,B-column and other parts are not only complex in cross-section,but also require high precision.It is difficult to meet its processing requirements for the traditional forming process.The safety performance must be the first priority in the future of automobile development.And as manufacturers,they hope to reduce the cost of the entire vehicle and maximize economic benefits.Therefore,the development of high-performance and low-cost cars is imminent.The emergence of roll forming technology and high-strength steel make this goal a reality.In this paper,commercial vehicle anti-collision beams with "?" cross-section made of high-strength steel have been developed and used widely.The anti-collision beam for commercial vehicles with the "?" cross-section is made of high-strength steel for the frame of the BL700.The productive process mainly includes two parts: the first part is to use roll forming technology to pass high-strength steel through the specified thickness and width of the roller with a certain surface while forming and welding.And finally the high-strength steel is continuously rolled into a "?" cross-section profile of commercial vehicle anti-collision beam.The second part is to use a pre-designed commercial vehicle bending device which is suit for the standard of GB26511-2011 to bend the profile to a certain angle to fit the body frame.In the above-mentioned forming process,the roll forming process is very complicated,and will be accompanied by defects such as springback and edge waves.In addition,during the rotary draw bending process of the profile,the inner side of the part withstands compressive stress and the outer side withstands tensile stress.Defects such as wrinkles and tears appear,and these problems need to be solved urgently.Based on the above problems,this paper uses COPRA software to design the pass.And then optimizes the generated roller pattern to meet the production requirements.And we import the roller pattern diagram into the ABAQUS software to generate 3D roller.Finally makes use of the one-time roll forming method and the rotary draw bending process to form the "?" cross-section.The main conclusions are as follows:Firstly,we model and simulate the "b" cross-section profile,and talk over the influence of Bauschinger effect and the sheet thickness on springback in the forming process.It is indicate of the result that when the bending radius of the sheet is constant.The springback angle decreases as the sheet thickness increases,which showing a linear relationship.The thickness directly affects the springback angle.Secondly,we analyze the influence of flange height,sheet thickness and forming speed on edge wave.The result shows that the above process parameters will all have an impact on the edge wave defects of the "b" cross-section.Its influence degree is that the sheet thickness is greater than the flange height and greater than the forming speedThirdly,we establish finite element analysis models of the rotary draw bending process with rigid die core,and discuss the improved method of the device and the causes of the forming defects of the profiles.Through the finite element analysis,we compare the forming effect of rigid core device in the process of the rotary draw bending.It is proved that the tension bending method of pre-stretching can obviously reduce the wrinkle and other defects.