| Application of high performance composites in the automotive sector that is the urgent needs of weight reduction, energy saving, emission reductionfor current vehicle,and that is accordance with thedevelopment planning of vehiclelightweight, safety,low energy consumption as the supply of international energy shortage.20 MN compo-site hydraulic press as a terminal equipment of LFT-D molding production line,it has great significance to design and research on it.According to the performance require-ments of 20 MN composite hydraulic press, PLC control system was designed, Based on this, the simulation research of systemcompression and holding pressure is carried out.Firstly, the structural characteristics and hydraulic system distribution of 20 MNcomposite hydraulic press are introduced in this paper.Based on the known technology parameters of hydraulic machine, calculated the system flow and linear pressure loss of hydraulic circuit. Then, introduced the general situation of research on multi valve parallel control, and analyzed the need of multi valve parallel controlforthe main cylinder hydraulic loop.Secondly, according to the process and performance requirements of 20 MNcomposite hydraulic press, the Fieldbus Control System based on PLC is established, whilethe Industrial Ethernet PROFINET and IO-Link connection system are selected to realize the optimization of the network structure. Then, the selection of the main control components is given. Based on this, the electrical drive system and the PLC main and slave station are designed.Then, the simulation research of compression and holding pressuresystem of 20 MNcomposite hydraulic press is carried out.The mathematical model of master cylinder loop proportional valve group is first built,based on this, build the MATLAB-Simulink simulation control modelof compression and holding pressure,through compared with the pressure-flow parameters in the proportional valve sample to verify the feasibility of proportional valve model.Then, the effect of the circuit leakage on the pressure speed and the pressure capability of the single valve is studied, and the pressure capability of the single within 0.5secondis tested by simulationBased on this, determined the parallel compression scheme of DG10.DG32 and DG80 valve.Finally, a proportional control scheme based on PID is proposed, and the proportional control parameters satisfying the requirement of compression are given by comparing the simulation results, this provides the basis for the next stage of pressure control.Finally, the software design of the control system of the hydraulic press is carried out, and the key control strategy ofthe pre commissioning is given,then the speed and displacement data of fast downwithout press and fast to slow process are analyzed, though this the feasibility of the control strategy is verified. Then the main disturbance sources of the system are determined by analyzing the velocity fluctuation data collected in the static state of the sliding block, and the feasible interference suppression measures are proposed. |
PDF Full Text Request