Design And Simulation Of Numerical Control High Speed Punch Hydraulic System

With the development of automobile industry, electronic technology and defence industry, more and more pressing machines especially high speed punches are demanded in domestic market. At present, the hydraulic system of high speed punch nearly adopts import completely, and it does not meet the national conditions of our country because of the high cost, so it is an important task to develop hydraulic system of the high speed punch which suits the present situation of our country. In the paper, a kind of numerical control high speed punch hydraulic system is designed. It has the characters of simple structure, high stepping frequency, and safety.In the paper, firstly, three design scheme of high speed punch hydraulic system are put forward and they are compared each other, then the optimum scheme is chosen. Secondly, the paper introduces not only the design and selection of the hydraulic elements, but also the design of the hydraulic cylinder importantly. In order to know the change of the dynamic parameters, we must study the dynamic characteristics of this hydraulic system. Based on this, the paper establishes the mathematical mode of the hi-speed punch hydraulic system. Sub-models of each element are established, then they are merged into a big system mathematical model according to the picture of topological relation. According to the work characteristic of the system, the working process is divided into three phases as falling differential motion, punching, returning fleetly, and we establish the mathematical models of these three phases. These three work phases are simulated and analyzed, and we gain several curves that the parameter variables changed with time. These curves are analyzed and put forward improved measure aiming at the problem of the system. At last, the paper joins PID control algorithm into the system, and adopts integral apart PID algorithm to control the system, then analyzes the simulation results. The stability of this system is improved after joins PID control method, and the system has good operating characteristic.The simulation results showed that the punch cycle is 0.2s and it can punch 300 times per minute and the biggest punching force is 200KN, when the thickness of punched steel plate is 1mm, and the stroke is 12mm. The system has smaller impact, working stabilization, and can satisfy design specification. This hydraulic system can make into the product and be launched into market, so the situation that the hi-speed punch in our county depended on importation will be changed.