Research And Application On The Key Problems In Automatic Power Press Equipment And Control System In Pneumatic Automatic Power Press Equipment

Initiating explosive device (IED) is the key part of arms,ammunition, other explosive system and combustion system. Pressing powder is the key technology of producing IED, with many important parameters such as pressure, speed, precision and holding time of press. which will directly affect the quality of IED. So, to develop advanced manufacturing equipment with high efficiency and reliability is an urgent affair.This subject originated from the project about automatic power press of loading materials for IED of the Chuannan Machinery Plant affiliated to China Aerospace Science and Technology Corporation. Research objects include two automatic power press equipments, one is electric power press equipment with high precision and the other is pneumatic power press equipment with lower precision. With in-depth study on the key technologies of automatic power press equipment and the whole system, especially the control system of pneumatic automatic power press equipment, this subject has completed following researches:(1) Study on mechanics character of IED. Making use of linear buffer with simple structure to overcome the nonlinear and time-varying problems during the pressing process. Analyzing the performance of different buffer according to the requests of automatic power press equipment. Analyzing results show that O-sharp linear buffer is satisfy the automatic power press equipment.(2) By establishing the finite element mechanical analysis model of O-shape linear buffer, the intensity of static load and yielding limit of the buffers in different sizes were made numerical analysis to find out the relationship between the size and stiffness of buffer. We also used TableCurve3D to got the formula between its size and stiffness.It shows that the most effective way to improve stiffness of O-shaped linear buffer is to thicken the wall of buffer, but not to widen it or reduce the outside diameter. Based on this result, we made out the real buffer and set the experiment. The result was in accordance with the finite element simulation result. It proves the validity of the finite element method. And the practical results also indicated that the O-shape linear buffer could effectively imbibe impact, overcome the nonlinear character and improve the press-controlling precision of system.(3) For other situation satisfied with lower press precision, we designed and analyzed the system of pneumatic power press, especially its control system, and also designed the responding software for control system.(4) Design an open-loop step response experiment based on pneumatic automatic power press equipment. Based on a great number of data by this experiment, we set the math model of generalized openloop transfer functions. According to the difference control requirements, we corrected the control system by lag-lead correction and PID control of classical control theory to get the time-domain response of the system with Matlab, which proved the validity of the system correction method and also could be taken as the reference for the future design of control system.