| Flanging process is a very important process in the manufacturing process of aerospace,automobile industry and other fields,which directly affects the forming accuracy of materials and the assembly quality of workpiece.As an important representative of lightweight materials,aluminum alloy plays an important role in manufacturing and processing industry.Traditional flanging technology is difficult to solve the problems of low plasticity,high rebound and easy tearing at room temperature,which seriously hinders the development of manufacturing and processing industry.Electromagnetic flanging technology is a new processing technology which uses pulsed electromagnetic force to drive metal workpiece forming at high rate.At present,the plate electromagnetic flanging technology usually adopts single coil loading mode,flanging process mainly depends on the axial electromagnetic force to drive the plate deformation.However,the plate flanging process consists of two parts: axial bulging and radial diameter expanding,and the electromagnetic force characteristics of single coil loading obviously cannot meet the demand of force field in the plate flanging process.Therefore,based on the single coil loading,this paper proposes a two-way loading method of axial and radial coils to provide the axial and radial electromagnetic forces for the flanging process of the plate.In order to achieve the above objectives,the method proposed in this paper is studied from the perspectives of double coil-double power supply loading and double coil series loading of two coils.It is proposed to optimize the characteristics of electromagnetic force,reduce the energy consumption of flanging and improve the forming quality from two aspects of system discharge voltage and coil structure parameters.The main research process of this paper is as follows:Firstly,the electromagnetic flanging process of single-coil loaded plate is analyzed,and the limitations of single-coil loaded plate are revealed from two perspectives of system voltage and coil turns number.When the voltage is increased,the discharge current in the coil also increases,and the electromagnetic force distribution of the whole plate is not fundamentally changed;Adjusting the number of coil turns can only optimize the flanging effect of the plate to a small extent,and the size of the electromagnetic force of the plate as a whole has not been greatly improved.Then,based on the influence law of system voltage variation on plate flanging during single coil loading,the system voltage of double coil and double power supply loading mode was studied.The simulation results show that the discharge voltage of the axial coil has a decisive effect on the flanging process of the plate.When the discharge voltage of axial coil and radial coil is divided into 3.1kV and 2.9kV,the flanging effect of the plate is the best,the flanging height of the plate reaches 19.2mm,and the radial displacement is also the largest.Compared with the single coil system,it is found that the coil current is smaller,the radial displacement of the plate is larger and the film is better.Finally,based on the law of the influence of the change of the number of coil turns on the plate flanging during the single coil loading,the coil structure of the double coil series loading mode was studied.The simulation results show that the number of turns of the radial coil has a greater effect on the flanging process of the plate in the double coil series loading mode.When the discharge voltage is 3kV,the plate flanging effect is the best when the axial and radial coil turns are divided into 2×4 turns and 4×4 turns,and the height can reach 17.1mm.Under the same discharge voltage,the comparison between the double coil series system and the single coil system shows that the double coil series system can effectively improve the radial electromagnetic force,and the axial and radial displacements of the plates are greatly improved,and the energy consumption for flanging and laminating of the plates can be reduced. |
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