Dynamic Modeling and Experiment of a New Type of Parallel Servo Press Considering Gravity Counterbalance  

作　　者：HE Jun GAO Feng BAI Yongjun WU Shengfu 

机构地区：[1]State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University [2]China First Heavy Industries

出　　处：《Chinese Journal of Mechanical Engineering》2013年第6期1222-1233,共12页中国机械工程学报（英文版）

基　　金：supported by National Science and Technology Major Project of China(Grant Nos.2010ZX04017-013,2010ZX04004-112);National Natural Science Foundation of China(Grant No.51205248);Shanghai Municipal Natural Science Foundation of China(Grant No.12ZR1445200);Doctoral Programs Foundation of Ministry of Education of China(Grant No.20120073120060)

摘　　要：The large capacity servo press is traditionally realized by means of redundant actuation, however there exist the over-constraint problem and interference among actuators, which increases the control difficulty and the product cost. A new type of press mechanism with parallel topology is presented to develop the mechanical servo press with high stamping capacity. The dynamic model considering gravity counterbalance is proposed based on the virtual work principle, and then the effect of counterbalance cylinder on the dynamic performance of the servo press is studied. It is found that the motor torque required to operate the press is a lot less than the others when the ratio of the counterbalance force to the gravity of ram is in the vicinity of 1.0. The stamping force of the real press prototype can reach up to 25 MN on the position of 13 mm away from the bottom dead center. The typical deep-drawing process with 1 200 mm stroke at 8 strokes per minute is proposed by means of five order polynomial. On this process condition, the driving torques are calculated based on the above dynamic model and the torque measuring test is also carried out on the prototype. It is shown that the curve trend of calculation torque is consistent to the measured result and that the average error is less than 15%. The parallel mechanism is introduced into the development of large capacity servo press to avoid the over-constraint and interference of traditional redundant actuation, and its dynamic characteristics with gravity counterbalance are presented.The large capacity servo press is traditionally realized by means of redundant actuation, however there exist the over-constraint problem and interference among actuators, which increases the control difficulty and the product cost. A new type of press mechanism with parallel topology is presented to develop the mechanical servo press with high stamping capacity. The dynamic model considering gravity counterbalance is proposed based on the virtual work principle, and then the effect of counterbalance cylinder on the dynamic performance of the servo press is studied. It is found that the motor torque required to operate the press is a lot less than the others when the ratio of the counterbalance force to the gravity of ram is in the vicinity of 1.0. The stamping force of the real press prototype can reach up to 25 MN on the position of 13 mm away from the bottom dead center. The typical deep-drawing process with 1 200 mm stroke at 8 strokes per minute is proposed by means of five order polynomial. On this process condition, the driving torques are calculated based on the above dynamic model and the torque measuring test is also carried out on the prototype. It is shown that the curve trend of calculation torque is consistent to the measured result and that the average error is less than 15%. The parallel mechanism is introduced into the development of large capacity servo press to avoid the over-constraint and interference of traditional redundant actuation, and its dynamic characteristics with gravity counterbalance are presented.

关 键 词：mechanical press parallel mechanism dynamic modeling virtual work principle 

分 类 号：TG385[金属学及工艺—金属压力加工]