Dynamic Analysis And Simulation Of The Four-link Weft Insertion Mechanism Of The Rapier Loom

The rapier loom is the most popular shuttleless loom in the world,and now it plays a more and more important role in the shuttleless loom.Domestic rapier loom which is low rotary speed,low efficiency,high failure rate and poor weaving fabric quality of woven fabric has a certain gap with foreign rapier doom.The weft insertion mechanism is the core mechanism of the rapier loom,and its dynamic performance seriously restricts the overall performance and efficiency of the rapier loom.The spatial four-bar linkage weft insertion mechanism is the object of this paper.The main contents of this paper are shown as bellow.The kinematic model of the spatial four-bar linkage weft insertion mechanism was established based on the space coordinate transformation method.Kinematics simulation was carried on with the programming and the kinetic characteristic curves of the sword belt were generated in MATLAB.Then discussed the influence of the motion law of the sword belt caused by the geometric parameters change of the components in the spatial four-bar linkage weft insertion mechanism.And these analyses provide the theoretical basis for the optimal design and dynamic analysis of the mechanism.The dynamic model of the spatial four-bar linkage weft insertion mechanism was presented by Lagrange equation based on kinematic model.The influence of driving torque and inertia force of sword belt with the change of rotate speed of the loom was analyzed,and the reasons of affecting and restricting the speed of the loom were found out.Taking the crank as an equivalent component,the influence of equivalent moment of inertia on the driving performance of the mechanism was analyzed,which provides a theoretical reference for the dynamic optimization design of the mechanism.By considering the flexibility of spatial linkage and cross axis which are the core components of the spatial four-bar linkage weft insertion mechanism,the mechanism rigid-flexible coupling model was established based on ANSYS and ADAMS.The effects of the flexible spatial linkage and cross axis on the output motion characteristic of the sword belt in different rotate speed of the loom was studied.Based on the ANSYS dynamics analysis of the cross axis,the maximum stress point of the cross axis was obtained.Those results provide a theoretical reference for the structure optimization design of the mechanism.