Error Analysis And Mechanism Optimization Of Wet Tissue Sticking Machine

When the plastic cover is pasted onto the wet paper towel bag by the wet towel sticking machine,the error of the paste position will cause the plastic cover to press the label on the wet paper towel bag,so that the wet paper towel cannot be pulled out.In order to solve this problem,the subject according to the paste process of the wet towel adhesive cover machine parts of the function and working principle of analysis,found that the cause of paste position error is mainly reflected in three links:synchronous belt transport plastic cover link;Flat belt conveying wet paper towel package link;Parallel manipulator grasping and pasting link.The error of synchronous belt transmission link of plastic cover has five aspects:the size of the synchronous belt itself process connection error,synchronous with adhesive stop position accuracy,synchronous belt chute size position error caused by the plastic cover,plastic cover material deformation error itself,and the synchronous belt conveyor plastic cover start to stop the error of inertial overshoot at a high speed.Through calculation,the inertia overshoot error has the largest value among all the errors and is the key error.In order to eliminate the error of inertial overshoot,in accordance with hooke's law puts forward four measures:change the plastic cover contact material increase contact surface friction coefficient,using torsional spring surface increases the stress on plastic cover,use a vacuum adsorption device between plastic cover and contact pressure,adopting elastic deformation in increasing thrust on the side of the plastic cover.By comparing the four solutions through experiments,the inertia overshoot problem of plastic cover can be solved by increasing the thrust force on the side of plastic cover through the deformation of elastic sheet.Finite element analysis tool is used to analyze the amount of stress and deformation of the elastic sheet.0.2mm thick stainless steel 304 is used as the elastic sheet material.The side thrust provided by the elastic sheet during deformation can realize the accurate positioning of the plastic cover.There are two aspects of errors in the link of flat belt transportation wet paper towel package:one is the error caused by the change of rotation radius caused by the change of the thickness of the flat belt,and the error caused by the change of the speed of wet paper towel package transportation line at the same speed.The second one is the error of the encoder on the flat belt.According to the calculation,the error caused by transporting wet tissue packages with flat belt is small,only± 0.314mm.The visual system of the parallel manipulator judges the position of the wet tissue package and the errors caused by the parallel manipulator grasping the plastic cover and sticking it to the wet tissue package have three aspects.First,the motion error of the parallel manipulator equals to the repeated positioning accuracy of the parallel manipulator±0.1 mm.The second is the error of vision system of parallel manipulator.The third is the error of gripper installation of parallel manipulator.The total error of the parallel manipulator is±0.8mm.The visual system of the parallel manipulator judges the position of the wet tissue package and the errors caused by the parallel manipulator grasping the plastic cover and sticking it to the wet tissue package have three aspects.First,the motion error of the parallel manipulator equals to the repeated positioning accuracy of the parallel manipulator±0.1 mm.The second is the error of vision system of parallel manipulator.The third is the error of gripper installation of parallel manipulator.The total error of the parallel manipulator is±0.8mm.Solving the inertia overshoot error caused by the transportation of the plastic cover on the synchronous belt will solve the problem of the adhesive position error of the wet towel adhesive cover machine.After improvement,the mean error of bonding position decreased from+1.806mm before improvement to+0.106mm after improvement,and the mean error decreased by 1.7mm.After the improvement of the equipment,the problem that the plastic cover can t be taken out because the plastic cover can't hold the inner label when the package is pasted with the wet paper towel is solved.This paper solves the problem of position error of light and thin workpiece in high-speed transportation.It can provide a solution to the position error problem caused by high-speed feeding of parallel manipulator.