Structural Analysis And Optimization Of The Die-cutting Mechanism In Automatic Die-cutting Machine

With the rapid development of the packaging industry, the market demands for die-cutting machine with high-performance is growing dramatically. However, from the viewpoints of the current products of the market, there is a large gap between domestic die-cutting machines and foreign advanced products in the processing speed, precision, stability and reliability of machine. For this reason, most of the domestic market is occupied by foreign products. So, it is urgent to improve the quality of homemade die-cutting machines. As die-cutting mechanism is the core of die-cutting, machine, the performance of its mechanical movement is very important for the synthetical capability and performance of die-cutting machine. Therefore, the in-depth study on the running principle for die-cutting mechanism and its kinematic characteristics is the key to improve its work ability and performance of the die-cutting machine, the scientific and rational optimized design of die-cutting mechanism is the fundamental measure to improve the the market competitiveness of domestic die-cutting machines.The author research is combined with some specific type die-cutting machine, and its systematic kinematics theoretical analysis of its drive mechanism has been done, and then, for the purpose of improving its kinematic characteristics and the quality of its cutting technics, a new project of conjugate, cam drive mechanism is established. By means of modern design methods, its structure comprehensive optimal and innovative design is completed. Thus, for guaranteeing its process precision, the processing speed of die-cutting machine has been increased at 1500r/h,and its synthetical capability and performance have also been improved relevantly. The main work and conclusions are as follows:First, the mathematical model has been established in accord with the existing specific type die-cutting machines, and then, by means of the theoretical mechanics analysis method, the solution of its movement is obtained, and then the mechanism movement equations for each component can be obtained exactly, the pictures of the mechanism displacement, velocity and acceleration change curve for each component can be also got through the analysis of MATLAB when die-cutting machine runs at the highest speed (6000r/h). According to kinematic analysis curve of the drive mechanism, the.main influencing factors and their influencing mechnisms to the working performance of the die-cutting mechanism are concluded. Among all factors, the cutting platform and acceleration movement of the connecting rod create the maximal influence on the cutting performance, their peak accelerations in the course of movement create high impact load, and the movement of the platform does not meet the requirements of die-cutting process for cutting technics.For the purpose of improving the kinematic characteristics of die-cutting mechanism and its die-cutting quality, the improved acceleration of the cutting platform is taken as the optimized design target, a new project of conjugate cam-driven mechanism instead of crank-driven is established. And an exact reverse design for die-cutting machine's structure is conducted by MATLAB, and then, the exact contours of the conjugate cam is got.Finally, ADAMS is applied to the conjugate cam-driven mechanism for its motion simulation analysis, for each component of the new die-cutting mechanism, their displacement, velocity and acceleration change curve can be got. When die-cutting machine runs at the design speed (7500r/h). compared with the result obtained in original die-cutting mechanism, the kinematic characteristics of conjugate cam-driven mechanism is more conducive to improve movement precision for the die-cutting mechanism, it can meet the cutting requirements of the die-cutting. The structure of conjugate cam-driven mechanism is more simple and compact, thus,it improves the capability and performance of die-cutting mechanism effectively.