Kinematics And Dynamics Analysis Of Sheet Transfer Mechanism For High-Speed Offset Press

A transfer mechanism is a key component of a printing machine,whose structure form and sheet transfer accuracy affect the printing speed and registration precision directly. At present,a swing transfer mechanism is widely used in domestic printing machine. But its printing speed is limited because of its swing inertia. However the rotary transfer mechanism is used by foreign printing machine like Heidelberg. Its printing speed can catch above 15000r/h, so it is accord to the demand of present printing machine.This paper use the rigid design and motion synthesis method to analysis the rotary transfer mechanism,confirm the movement rule of transfer gripper, and the profile of the driving cam was worked out by motion synthesis of the mechanism in the condition of rigid hypothesis and then the dynamic analysis was performed.1. According to the demand of the motion course of the transfer mechanism for the high-speed offset press,choose the motion rule of 5 polynomial,7 polynomial,modify sine and modify trapezoidal acceleration to analyse. After comparing with their character motion curve, we choose the rule of modify trapezoidal acceleration for the transfer gripper.2. Establishing the coordinate of rotary transfer mechanism with the principle of conjugated surface. Kinematic synthesis proceeded from the transfer gripper by using conjugated surface solution then the movement parameters of every part of the linkages were investigated. The cam figure and relative parameters including press angle, radius of curvature were calculated,finished the rigidity design of the transfer mechanism.3. The loads and the driving-torque were studied based on the dynamics static principle. The motion character curve of every rods were gived with using MATLAB. It shows the rigid kinematic properties and effect, provided a warrant for the design of the transfer mechanism.4. Given the reasonable supposition, the mechanism was simplified to a mathematical model of elastic-body system. The dynamic response of the gripper was worked out by solved the vibration equation. It was proved to be feasible that the mechanism was designed with the rigid hypothesis under the speed of 15000r/h. Thus the design of the rotary sheet transfer mechanism was completed.