Resistance Heating Experiment Of High Strength Steel And Mould Design Of Torsion Beam

As the environmental problems become more and more serious,automotive lightweight is imperative.High strength steel is used in automobile bodies to provide safety protection while reducing weight.Therefore,high strength steel is more and more used in automobile parts.In the hot stamping technology of high strength steel,the choice of heating method affects the whole production cycle,and the selection of suitable heating method is of great importance.Event based control scheme was used to realize the automation of the hot stamping process.The production line includes the resistance heating equipment.On this basis,the method of resistance heating for tube is further explored.The electrode scheme for holding tube and torsion beam mould is designed.First,based on the existing resistance heating equipment in the laboratory,the electromagnetic valve control circuit is designed to control the cylinder open and close.The cylinder is used in the mechanical gripper and the electrode.In addition,the control of the resistance heating power supply part and the servo motor to drive the sliding part is discussed in detail.It is an effective method to solve the control problem of expansion in the heating process.After the completion of the above work,various parts of the input and output signals are connected to the robot standard I/O board.Control programs are written to realize the automation of the hot stamping process.After the completion of the rectangular blank heating test,the paper also explains how to use this device to heat tube for the study,two schemes about the tube electrode are discussed.Finally,the finite element software is used to simulate the forming process and the quenching process of the torsion beam.The forming simulation mainly deals with the forming flow,forming defects and stress distribution of the tubular specimen.The results show that the flow velocity of the upper half and the lower half varies greatly.The stress distribution is uneven,and the damage location is concentrated in the joint of the upper half and the lower half.Explanations for the causes of the simulation results are also given.These analyses have important reference value to mould design.In the tube forming and quenching simulation,the temperature change of the torsion beam analysis was performed using five groups of 10 s,15s,20 s,25s,30 s,the stress distribution are simulated and analyzed.The results show that Martensite transformation has been obtained after cooling time is more than 20 s.After quenching of 20 s or 30 s,the residual stress in the parts decreases significantly.This paper also compares the two design schemes of the forming die of torsion beam.The design of the multidirectional die adopts a plate structure,and the concave convex die is divided into blocks and is connected with the insert blocks.The cooling system of the die is analyzed by finite element method,and the optimum parameters of the cooling hole are obtained.In the design of the rectangular section of torsion beam,two schemes are discussed,and the advantages and disadvantages of the two schemes are compared.A lateral die core and a moving mechanism with better formability are designed.