| Numerical control bending machine is a kind of special purpose machine, which bears the trait of high degree processing technique and yields the bending plates of high precision, using the digital control and the automation of the processing. As the current large scale metal plates own the characteristics of the high energy consumption and the low precision of synchronous control, it is essential to design a power matched energysaving bending machine. It can not only meets the need of the precision of unsymmetrical cylinder synchronous control in the hydraulic system of the bending machine,but also reduces the energy consumption to its minimum.This thesis, based on analyzing the hydraulic synchronous control system of numerical bending machine from home and abroad, aiming at the current structure and working principle of numerical bending machine of energy-saving hydraulic synchronous control system, puts forward a power matched numerical bending machine of energysaving hydraulic synchronous control system. The hydraulic system is realized through using load-sensing variable pump, which matches the stress needed, flow and the stress flow of pumping source to extremely enhance the efficiency of the system. It employs the LUDV system, which distributes the flow equivalently to each actuator, to realize the synchronization of the hydraulic system. Finally, it adopts PID to control the system and to further increase the precision of the synchronous control.This paper contains the following seven parts:(1) Presenting the current status and developing tendency of the hydraulic synchronous control system of numerical bending machine in home and abroad.(2) According to the working situation, synchronous and energy-saving requirements,and connecting the merits of the electric and hydraulic proportional and load-sensing technique to design the plan of the hydraulic synchronous control system of numerical bending machine.(3) Researching the simulating theory of the hydraulic synchronous control system of numerical bending machine to construct the transfer function of each part in the system,and analyzing each parameter's effects to the dynamic and steady specialty.(4) Adopting high-ranking AMESim modeling and simulation software to construct the AMESim simulation model of each component and the whole system in load-sensing energy-saving hydraulic synchronous system, then simulating the model and analyzing factors which effect the synchronous control precision in load-sensing energy-saving hydraulic synchronous system.(5) Researching the measures of load-sensing energy-saving hydraulic synchronous system, introducing the fundamental structure of the system, analyzing the similarities and differences of the structure. Presenting the theories of traditional PID control, crosscoupling and mono-neuron PID control, and analyzing the similarities and differences of the control.(6) Employing AMESim and MATLAB/Simulink to wholly simulate the model,analyzing and comparing the precision of every synchronous control and the settling time.(7) Comparing in pairs the metering pump speed governing system, LS system and LUDV system when completing the same working conditions of the bending machine,and analyzing its energy conservation. |
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