Papers by Author: Hong Chen

Abstract: Synchronization torsion bar is a key part in independent and dependent impression mechanism which ensures synchronization motion at both ends of blanket cylinder. Due to frequent action of the mechanism in high-speed printing, synchronization torsion bar would cause huge impact torque so as to affect parallel shifting of blanket cylinder and uniformity of printing impression. Based on structure features and force of synchronization torsion bar, finite element model of synchronization torsion bar was established by adopting structural mechanics and finite element method, then static stiffness of synchronization torsion bar was solved by adopting principle of minimum potential energy. The result of computation shows that the maximum torsion deformation of torsion bar in X direction happens at the left connection point. Because the deformation is very small, the bar can meet the requirements that blanket cylinder.

Abstract: Each component of die-cutting machine at high speed may produce vibration and die-cutting quality would be affected in different degrees by direct or indirect vibration. Position accuracy of paper-conveying grippers may be an important influencing factor. Under some suitable hypothetical conditions, single degree of freedom no-damp dynamic model was established based on transferring principle of mass and stiffness equivalence and principle of equivalent substitution. Position process has been discussed at high speed, dynamic displacement deviationresponse spectrum has been gotten by numerical computation method in cam resting rang. The result of the analysis and computation shows that position error has an increasing tendency with the increase of the working speed. So it is vitally necessary that the maximum speed of die-cutting machine must be limited to meet die-cutting accuracy requirement when natural frequency of the machine is known.

Abstract: Position stability analysis of gripper bars on die-cutting machine is one of the important factor which affects machining quality and production capacity. By introducing comprehensive influence parameter period ratio such as machine speed and mechanism natural frequency,mathematical model of gripper bars in stopping period has been established. The results indicate that dynamic motion error of gripper bars in stopping period show an increasing tendency so as to affect stable position with the increasing of period ratio. To ensure a stable position state in stopping period, finally two solutions are given out to satisfy high accuracy.