Design And Test Of Automatic Equidistribution Device For Tangential And Longitudinal Flow Grain-MOG Mixture

As one of the most important food crops in China,rice planting has a wide planting area and large area;high yield per unit area and large total output.During the “Twelfth Five-Year Plan” period,China's agricultural mechanization increased steadily,and the mechanization rate of rice harvesting reached more than 90%,with 1.739 million units of combine harvesters.At present,with the improvement of agronomic technology("super rice","high-efficiency fertilizer",etc.),rice yields have increased rapidly;the development of new family farms has also led to the transformation of rice production(10-15 mu per field)into production and harvesting forms,and the market is increasingly demanding large-feed combine harvesters.The cleaning performance is the core evaluation index of the combined harvester performance,so the research on the large feed combined harvester cleaning device is very critical.In the paper,the tangential-longitudinal flow combine harvester is taken as the research object,and the reduce of the cleaning loss for the purpose of research.In view of the problem of uneven distribution of the grain-MOG mixture,an automatic equidistribution device for the grain-MOG mixture is designed on the return conveyor.Improve the adaptability of the automatic equidistribution device and design the corresponding monitoring system.The main research contents are including:(1)Design of automatic equidistribution deviceAccording to the operation principle of the tangential-longitudinal flow combined harvester,design corresponding cleaning device.The cleaning device consists of three parts: vibration seive,double outlet multi-channel centrifugal fan and return conveyor.The distribution test of the tangential-longitudinal combined harvester extract is carried out,and the law of unevenness of the extract is obtained.The movement of the return conveyor are separately analyzed to find out why the existing return conveyor cannot uniformly distribute the laterally.Installation scheme of fixed diversion bar is added to the return conveyor,adjustable diversion bar and its adjusting structure are designed to improve the uniformity of distribution of MOG-grain mixture.(2)Influence of the angle of the guide strip on the motion and distribution of the grain-MOG mixture based on EDEM simulationTaking the angle of the guide bar as the research factor and rice as the research object,the influence of the angle of the guide bar on the motion,efficiency and distribution of the extract was analyzed by EDEM simulation.The simulation particle was designed based on the distribution experiment of the tangential-longitudinal combined harvester.The particle factory simulates the fixed guide strips of the design and an optimization scheme is proposed based on this;the standard deviation of the number of the extracts is used as the evaluation index,and the design scheme,the optimization method,and the comparison scheme without the guide strips are discussed.It is concluded that the standard deviation of the distribution of the extracts without the guide strips is 3.9,the standard deviation of the distribution of the extracts of the design scheme is 3.3,and the standard deviation of the optimized scheme is 1.57,and the optimized guide strip scheme is obtained.The cloth capacity is 55% higher than that of the backhaul-free conveyor,which is 52.5% higher than the design.(3)Lateral grain-MOG mixture distribution monitoring device studyThe principle of lateral grain-MOG mixture distribution monitoring is proposed,and the corresponding monitoring device is designed: the selection pressure sensor and the speed sensor are used to build the hardware system with PLC as the controller.According to the monitoring requirements,the PLC as the lower computer,the LabVIEW as the upper computer and the communication program are designed.Firstly,the intelligent cleaning test bench is transformed.Secondly,the monitoring board thickness and installation angle is taken as the research factors and the bench test is designed.Thirdly,the influence of the monitoring device structure on the monitoring signals are conducted.Finally,the optimal monitoring device parameter combination is obtained: the monitoring plate thickness is 8mm and the installation angle is 40°.Finally,(4)Design of fuzzy controller and field test verificationBased on the fuzzy control principle,the fuzzy control strategy of the adjustable guide strip is developed and the corresponding controller is designed.The automatic equidistribution distribution device was prototyped and installed on the deep mud foot rice combine harvester,and the field loss test was designed to verify the effect of the automatic equidistribution distribution device.The field experiment result shows: When the machine advance speed is 1m/s,the standard deviation of the monitoring quality percentage in each region decreases from 3.0 to 1.2 after the adjustment of the automatic distributing device,and the cleaning loss rate decreases from 1.2% to 0.34%.When the current advance speed is 1.5m/s,the standard deviation of the monitoring quality percentage in each region decreases from 3.5 to 1.5 and the cleaning loss decreases from 0.9% to 0.45% after the adjustment of the automatic distributing device.According to the field experiment,it is concluded that the automatic distributing device is helpful to improve the evenness of lateral distribution and reduce the cleaning loss.