| Currently,mechanised rice straw return has become one of the main methods of straw disposal in northeast China,but there are problems such as the difficulty of decomposing straw directly to the field.In order to solve the problem that the current agronomic model for returning straw to the field in the cold region of Northeast China cannot decompose straw in a timely and effective manner,this study proposes a new way of returning rice straw to the field by trenching and burying,and designs a rice straw trenching and burying machine that can complete the operation processes of trenching,raking,spraying of decomposing chemicals,mulching and suppression in one go.The research and design of the rice straw furrowing and mulching machine is carried out by means of theoretical research,field verification and data statistics.(1)Based on the planting mode and agronomic requirements of rice in the cold regions of Northeast China,a rice straw harvesting and burying machine was designed,which can complete multiple operational processes such as trenching,harvesting,straw entry,application of decomposed chemicals,and soil covering and pressing at once.Key research was conducted on the chain trenching device,single side grazing device,pesticide spraying device,and soil covering and pressing device,and the design parameters of key components were determined,And the 3D design software Creo was used to model and assemble the rice straw harvesting,burying,maturing,and returning machine.(2)Based on soil and straw particle parameters,the two-way coupling method of Recur Dyn and EDEM numerical simulation software is used to deal with the interaction between the ditching device and the single-side raking device and the particles,to investigate the formation process of the ditch body and the throwing mechanism of soil and straw particles,and to provide theoretical and data support for the subsequent finite element analysis of the whole machine and the optimal working parameters of the single-side raking device.(3)Taking the designed rice straw harvesting and burying machine as the research object,a finite element model of the returning machine was established using ANSYS Workbench software.By applying loads and constraints,the rationality of the entire machine structure was analyzed,and the dynamic analysis was focused on the trenching installation of the main working components of the returning machine.After loading and solving,the finite element analysis results were obtained to identify the maximum stress position.And the first six rigid body modal shapes were solved through modal analysis,and the distribution of the first six modal shapes was analyzed.Then,based on the modal superposition method,perform harmonic response analysis and solve for the phase frequency response curve,ultimately identifying the components most susceptible to fatigue damage.(4)Based on the previous work,the prototype was processed and trial produced,and the feasibility of the rice straw collection and burying and maturing machine for returning rice straw to the field was verified to meet the agronomic requirements of returning rice straw to the field and the subsequent straw ripening situation.Field experiments were conducted at the Acheng Experimental Base in Harbin,Heilongjiang Province to explore the impact of different working parameters of the returning machine on the straw returning rate,and a mathematical model was established to solve the optimal parameter combination,Provide theoretical basis and data reference for subsequent optimization design,and track the decomposition of straw in the future.Through experimental data analysis,it is determined that the operational indicators meet the agronomic requirements of returning straw to the field. |
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