| Die-cutting machine,also known as cutting machine,is the main industrial equipment in printing,packaging,parts forming and processing,etc.This paper researches the chain drive system of the die-cutting machine,mainly through the analysis of the structural characteristics and the transmission principle of the die-cutting machine,and the analysis of the rollers and sprocket’s the meshing process in the transmission process,uses the generalized Lagrangian equation method to establish its dynamic model.The fourth-order Runge-Kutta method is used to solve the dynamic differential equations in MATLAB software,and analyzing its dynamic characteristics.The main research contents of the thesis are summarized as follows:Firstly,analyzed the chain drive system’s structure,work principle and the rollers and sprocket’s the meshing process in the transmission process,and obtained the theoretical force of the chain link in the transverse and vertical directions and the amount of deformation caused by the meshing impact.Then the mechanics principle is applied to Research,hypothesize and simplify the chain drive system.Finally from the sequence of simple to complex,a intermittent chain drive dynamic model is created based on the Dubowsky clearance processing model and including chain guides,link hinge clearances,tension spring stiffness,damping and other factors.The generalized Lagrangian method is used to calculate the corresponding differential dynamics equations.Secondly,the finally obtained dynamic equations of the die-cutting machine’s intermittent chain drive system with clearance are solved by programming using the fourth-order Runge-Kutta method in MATLAB software.And based on the system equations in the form of a matrix after sorting out.The first 7 natural frequencies of the transmission system are analyzed and the transmission load caused by the excitation force is analyzed.It is found that the high-speed chain is greatly affected by the centrifugal action of the sprocket,the circumferential force and the loose edge sag.Finally,the polygon effect that affects the stability of the system transmission is analyzed.Based on the research and comparison of the cam motion curve,the common modified sine motion law(MS),modified constant velocity motion law(MCV)and modified trapezoid are selected.The law of motion(MT)is used as the input of the stepping chain drive system model by changing specific system parameters such as the gap size of the link hinge,the stiffness of the support shaft tension spring,damping,the speed of the sprocket,the concentrated mass of the chain and the magnitude of the pre-tightening force,The vibration response of the stepping chain system under the three cam motion laws is obtained,and the response changes are analyzed to find out the parameter control method to improve the stability and accuracy of the stepping chain transmission system;in addition,the stepping transmission.The analysis of the torsion force of the middle sprocket shows that the driven sprocket has a hysteresis system relative to the driving sprocket;when the chain tension changes in speed and pre-tightening force,the force on the chain presents a periodic change law related to the cam law curve.The research content of this article provides theoretical guidance for the kinematics and dynamics analysis of mechanical systems containing the intermittent transmission chains,such as die-cutting machines,book and food packaging machines and mine conveyors,provides a certain theoretical reference for this type of chain driven system in terms of the system parameters’ choice and optimization in chain vibration reduction,and provides a reference for the further research of the chain drive system. |
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