Corn Stubble Harvest Mode And Mechanisms

Yield of crop stubble is rich, which has excellent physical, chemical and biologicalcharacteristics. More and more attention has been paid to the outstanding developmentapplication potential. Lateral stubble system of corn is strong, growing around, andclosely combines with soil. Moreover, the soil is often enveloped in the central of thestubble, which is not easy to separate, bringing difficulty to the mechanization of cornstubble harvest.Consequently, According to a project supported by National Hi-tech Program, adeep research for relevant contents of corn stubble harvest was performed, exploringharvesting mode, and establishing scientific and reasonable harvesting route. Varioustheory problems, in the process of harvest were studied, and the mechanical models ofkey mechanisms were established, some key parameters which have model controllingfunction were developed, and then the model optimization was conducted aiming at theharvesting performance. Meanwhile, a corn stubble harvest test platform was developed,which set shovel-dig, scouring off soil from stubbles, hoisting and gathering stubble in abody. By means of theoretical model to guide for establishment and optimization of theplatform, the models were validated and revised with mechanical test platform. Finally,we use test optimization design method to optimize the system, through optimizingparameters to determine ideal composite mode of the structural parameters, in order toimprove system performance.Depend on the landform and basic physical attributes of the corn stubble field, weobtain basic data of the soil and corn stubble and the morphological and mechanicalmodel were established, which provided basis for development of harvest system. Basedon TRIZ theory and method, the basic composition of corn stubble harvest system,function mode, and key technologies were studied, the main structure form of the systemwas forecast, and the "material-field model" for shoveling-digging and scouring soilfrom the stubble was set up. Then the contradiction between mechanisms was resolved,and the scientific direction of innovative design of harvest system was point out. Usingvirtual prototype technology, corn stubble harvest experiment platform whose parametersare adjustable was developed, providing better platform fundation. Shovel blade form forcorn stubble with multi-stage shearing angle was designed and optimized based onslippery cut dynamics model. Through establishing the dynamic model of stubble in the wobble plane, the critical condition in implementing stubble hoisting and beating wasdetermined, and the combined parameter mode of wobble system for separating soil fromstubbles was optimize. Based on friction self-locking theory, the force model in criticalstate was established when stubble is feeding, the key parameters affecting theperformance of stubble feeding was determined. Through the research method ofcombining theoretical and experimental mode, the system dynamics properties of thestubble harvest structure were obtained, the modal parameters and system modes weredetermined, and the basis for the improving system dynamics for scouring was provided.We combines theoretical study with tests the wobble soil system and rollingpulverize optimization design, considering driving speed, chain inclination, location ofthe wobble wheel, clearance between the two rollers as experimental factors, and thecleaning rate and the efficiency of scouring soil as optimal objective. The research ofscouring soil system and rolling wobble broking soil were performed and the relevantmodel was set up. We applied genetic algorithm of multi-objective nonlinearprogramming model to search the optimization and verified the operation state when thesystem is under the optimizing parameters. Meanwhile, we employed high-speedphotography technology to record and analyze the process when the corn stubble is inwobble state for scouring soil. Finally, the adjustable parameters of the harvest system tooptimal value were set; a comprehensive test for the scouring soil performance of thewhole machine was performed. Therefore, the rate of scouring soil up to86.7%, andsingle stubble through a processing duration take an average time of4.87s.