Dynamic Characteristic Analysis And Experimrntal Study Of Copier Paper Feeding System

With the continuous improvement of China’s comprehensive strength and the rapiddevelopment of economy, the office automation system becomes more and more popular andimportant, as the basic equipment in office automation system, copier has become anindispensable tool in daily work. Stable and accurate paper feeding and paper transferring is thekey to ensure successful scanning and copy. At the same time, in the paper feeding system ofduplicator there are varying levels of "paper jam" phenomenon, which greatly affect theefficiency of the copier. In this dissertation, the dynamic characteristic of the paper feedingprocess is studied through theoretical analysis, simulation and experiment. Based on the dynamiccharacteristic analysis during the process of paper feeding, the solution for paper jam is proposedwhich provides reliable basis for the reasonable structure design and more accurate papertransferring.In order to improve the reliability of paper feeding, the standard of successful feeding isproposed under the study of paper feeding process through friction. Furthermore, a mathematicmodel is built based on paper separation scheme. Finally, conclusions are made under numericalanalysis of the model. The results show that the success probability of paper feed is directlyproportional to roller rotate speed, and inversely proportional to normal compression. On theother hand, the success probability of paper feed is unrelated to the mean coefficient of frictionand inversely proportional to the standard deviation of the coefficient of friction.The method and theory of the paper separation are studied in order to solve "double feed"problem in copier paper feeding unit. The paper separation mathematic model of Feed andReverse Roller (FRR) method is built. The trajectory of two layers of paper in the paperseparation process and influencing factors are obtained which provides reasonable design of thepaper separation stricture.An unconstrained motion problem of feeding paper during transition phase of two paperpaths is studied by using theoretical, simulation and experimental method. By using thenumerical analysis method, the bending deformation of paper is inversely proportional to feedingspeed. By adjusting the acceleration and the feeding angle of paper, to change the paper edgeposition, the paper could be transferred accurately. Meanwhile, by simulating the unconstrainedmotion problem of feeding paper in multi-body dynamics software RecurDyn, and do theexperiments of feeding dynamics deformation by varying the feeding speed, the correctness ofthe conclusion from theoretical analysis is verified.The contact area mechanical characteristics of the feeding system of roller rolling arestudied on. Through geometric analysis，it is known that the contact width and average contact pressure of the paper feeding roller contact area are directly proportional to the square root of thenormal pressure. The quantitative relationship between contacting width and normal loadpressure is obtained by a quantitative analysis of contact width and contact pressure in thecontacting area by using the elastic contact theory, which will be applied in the speed analysis ofpaper and roller.The paper presents an adaptive meshless method base on the strain energy gradient theory,the weight function and the adaptive node encryption technique are both discussed.Under the cylindrical coordinates, the contact problem of rubber roller is analyzed byutilizing the stress function with power series first time. By applying adaptive meshless method,which is based on strain energy gradient theory, stress distribution area, elastic layer thickness ofrubber roller, and the relationship between normal pressure of roller and its contact area stressdistribution are all determined. Also, the elastic layer thickness and the relation between normalpressure and the deflection of elastic rubber roller are evaluated.Based on the analysis of roller over the problem of contact, it is the steady and speed of themotion for the feeding paper under grip roll is related with the dynamic characteristic of rollercontact area. The speed of feeding paper is mainly determined by the surface speed of rollercontact area, the surface ratio between rubber rollers and paper is known, by the modeling,analysis and solving for the motion problem of paper under grip roll, also the factors which affectthis speed. The results show that the surface velocity ratio between paper and the upper roller isdirectly proportional to elastic layer thickness of the lower roller, which is also directlyproportional to normal load of roller for the same thickness of roller elastic layer. The rollerelastic layer thickness should be taken into account in the design of copier paper feed is proposedfor the first time.The paper presents a method to obtain the velocity of feeding paper, which shoot the motionof feeding paper by high speed camera and then handle it by the image processing technology.The bending deformation of paper transferring from horizontal path is measured and analyzedwhich verified the conclusion of chapter2is correct.