Performance Analysis And Optimal Design Research On Reed Motion Mechanism Of Knot Netting Machine

As an important part of the knot netting machine,the reed movement mechanism will directly affect the performance of the whole machine along with quality of the finished product.In this paper,the reed movement mechanism is taken as the research object,and the kinematic performance is analyzed.The main factors of abnormal sound,vibration and motion instability during the operation of the reed movement mechanism are discussed,and these factors are optimized.The construction method of cam contour is optimized,and the NSGA-II algorithm is applied to the multi-objective optimization of the up-down cam-link mechanism.The main work and conclusions of the paper come as follows:Firstly,the operation principle of the knot netting machine and its reed movement mechanism is analyzed.Based on a top-down collaborative design method,the Creo software is used to prototype the 3D model of the reed movement unit.It is imported into the motion/dynamics software Adams virtual prototype to analyze the motion performance of the mechanism,and the main reason for its poor motion stability is that the cam contour of the mechanism is not smooth.Next,for the cam member in the orifice mechanism,the cam curve of the reed movement mechanism is optimized,considering the maximum dimensionless velocity,acceleration,jerk and torque of the cam curve characteristic value,according to the specific movement requirements of the reed movement mechanism,The fuzzy comprehensive evaluation method is used to determine which cam curve is most suitable for the cam-link mechanism of the reed movement mechanism,and the amplitude modulation is optimized on the basis of the preferred cam curve.The optimized motion of the swing arm follower is performed in Creo.The inverse solution of the cam contour is applied,and the optimized cam member is assembled into the original assembly for simulation verification,and the effectiveness of the optimization method is discussed.Then,for the cam-link mechanism in the reed movement mechanism,performance analysis and strength verification on the drive spindle to verify whether the spindle strength is sufficient and stable during the work is performed.The key factors affecting its transmission performance are analyzed,and a multi-objective optimization mathematical model of the upper and lower motion mechanisms on the basis of this is built,and the accurate representation of mathematical models to make it more conducive to solving is discussed;The solution is optimized based on NSGA-II algorithm,defining a set of optimal design schemes,and the new design scheme is implemented and introduced into the assembly model to verify the effectiveness of the optimization method.Finally,the physical prototype verification of the reed movement mechanism is carried out for the optimized scheme.The results show that compared with former optimization,the scrap rate is reduced to a certain extent,the production efficiency is slightly improved,the abnormal sound of the reed movement mechanism is controlled,and the stationarity of the machine has been improved.In summary,this paper takes the motion mechanism of the knot netting machine as the research object,and design of the cam member feature quantity and the cam link combination mechanism performance index are optimized,which improves the motion/dynamic performance of the mechanism.Production efficiency has been increased,noise and vibration problems has been improved.