Optimization Design of the Web Press’s Fold Mechanism Based on Robustness

Abstract

With the increasing of printing machine’s working speed, the minor changes of design variables will decrease mechanical precision and stability in working state. So, high-speed and high stability are the tow mutual restraint aspects in modern printing machine design. The web press is the highest printing speed and large-scale with, but the stability of fold mechanism is the most significant constraints to speed. In order to increase the mechanism speed and stability, the two robust criterions, kinematics and dynamics precision, has been proposed. Through the kinetic analysis to the fold mechanism of web press, the dynamic model of the mechanism response to design variables has been established. By the model, the optimization model has been established based on robust analysis. Through the robust model, seeking the design variables with the best robustness，the goal of increasing the mechanical long-term stability in high speed can be attached in the condition of ensuring the fold precision. The design example shows that in the case of the stable design variables, the kinematics performances of robust design and trace optimization design are slightly different , but the dynamic performances of robust design are much better than that of trace optimization, and in the case of the design variables’ slight changes, robust design can make the mechanism’s dynamic performances still maintain, but the trace optimization doesn’t. In short, robust design is a good way to increase the stability of machine.