Roll Forming Parameters Modeling And Optimal Design Of Symmetric Six-rollers Vertical Bending Machine

Bogie side frame cover plate is usually formed by bending process at present.The bending process not only need to machine mould but also has long die trial cycle and high manufacturing costs.After forming the circular arc of the workpiece is not smooth,the production cycle is long.However,roll bending is a kind of no mould material forming technology.It has many advantages such as save cost and high production efficiency.So it is widely used in construction,automobile manufacturing,shipbuilding and machinery manufacturing and many other fields.Roll forming process applied to the bogie side frame cover plate production can greatly improve the processing quality and level and thus improve the bogie assembly quality and make the train running safety.In this paper,a non-typical roll bending device is studied.The roller layout is different with the general three or four roller bend forming equipment.The driven roller spacing is fixed.Therefore,the traditional process parameters calculation method may not apply to the device.While developing process for new workpiece,technologist needs to test many times in order to determine the reasonable forming process.Moreover,the stress condition in its forming process is relatively complex.It involved material nonlinearity,geometrical nonlinearity and boundary nonlinearity and so on.And combined with the material spring-back factors,the determination of molding process parameters has the certain difficulty.In this paper,the structure characteristics and working principle of the special device are analyzed.Based on it,the roll bending parts machining process is determined.And through simplify the roll bend forming system mechanical model,the theoretical formula is set up to realize the main roll bending parameters design.Based on this,the 3D finite element model of sheet and rollers is built respectively.The process parameters obtained from theoretical model is optimized by several numerical simulations.Then,the process parameters of several common molding sizes are determined for a given material type.Finally,the proposed theoretical model and identified spring-back amount of typical size by simulation is verified through physical test.Results show that the proposed model has good applicability.And the obtained spring-back amount by the numerical simulation method is reasonable,because it meets the designed requirements.At the same time,the application procedure is developed to improve the calculation efficiency of the roll bending parameters.The procedure can realize the automatic design of roll bending parameters and output the related parameters to a file or serial port.According to the data read from AutoCAD model file and the calculation results,the 3dMax simulation model of roll bending plate forming process is established.It can implement the animation simulation of roll bending process.And a bogie side frame cover plate forming instance verified the application procedure to calculate the roll bending process parameters is feasible.