| The annual output of rice straw in China exceeds 200 million tons,and it can be used in animal husbandry,industry,new energy and other fields after processing.With the improvement of people's living standards,the demand for livestock products is increasing.The straw with loose structure and scattered distribution is used as a silage after baling operation.It not only reduces the cost of harvesting,storage and transportation,but also plays an important role in reducing environmental pollution and resource waste in agricultural farming regions,protecting grasslands in pastoral regions,and improving the quality and production efficiency of livestock products.Moisture content is an important process requirement in the processing of rice straw for silage.However,when domestically produced small and medium-sized steel roller balers are used to bundle rice straw with high moisture content and relatively wet and hard,it is prone to rollage or clogging,especially for intact rice straw.To this end,this article has done the following work separately:the friction characteristics of rice straw were studied separately;the mechanical analysis of the rice straw was introduced;the design and experiment of the conductivity experimental equipment;the design & manufacturing and performance experiment in the field of the whole machine.A silage rice straw round baler was designed to integrate baling and spraying liquid microbial agents.In order to provide new methods and ideas for the application and optimization design of this model,the specific content and conclusions are as follows:(1)Study on the friction characteristics of rice straw.A two-factor experiment was carried out based on the moisture content of rice straw and different materials of roller surface as experimental factors.For the common materials of the guiding operation equipment: ordinary carbon steel,oxford cotton canvas,PVC straight conveying tape,using the sliding friction coefficient as the experimental index,a self-made friction coefficient experimental equipment based on a bevel meter and a visual interface is used to the experiment.Through the analysis of the variance of the two-factor repeated experimental results,obtained the influence of moisture content,material type and the interaction between the two on the sliding friction coefficient between rice straw and different materials of roller surface.(2)Process analysis of conveying the rice straw by the conveying roller in the baling mechanism.Through theoretical analysis,the following conclusions are obtained:the effect of the impetus and resistance received by the rice straw during the baling process;the reason of the problem of winding or clogging;the height of the guiding is proposed as an index for evaluatingthe guiding performance experiment of the baling mechanism;the solution is to solve the problem of winding or clogging by changing the surface material of the guide roller,the surface structure,and reducing the gap of the guide roller.(3)The experimental equipment for the guiding performance of the baling mechanism was designed and manufactured,and the single factor experiment and the Taguchi experiment were carried out for the key factors affecting the height of the rice straw conveying.The single factor experiment results show:if the coefficient of friction between the material of the guide roller and the straw is larger,the guiding performance of the guide roller is better.Using Design-Expert software to analyze the results of Taguchi experiment,the contribution rate and influence law of each factor on the index were obtained,and the better combination scheme was determined:type of oblique upward guiding roller:tape material&ribbed fitting&intermittent arrangement;type of guiding roller in front of the transverse direction and longitudinal direction: canvas material&nonedge fitting&intermittent arrangement;guiding roller rotation speed:210r/min;feeding speed:1.5m/s.(4)The design and selection of the round baler machine for silage rice straw and its key components were completed,and the working principle was clarified.The virtual prototype technology of CATIA V5 software was used to carry out three-dimensional modeling,assembly and layout design of the whole machine and key components(coiling mechanism and liquid microbial spraying device).The modal analysis and static analysis of the side wall of the baling mechanism and the support frame of the tank were carried out by ANSYS workbench software.The results show that the frequency of the excitation source does not coincide with the natural frequency of the sidewall,and the sidewall does not resonate.The optimized maximum stress of the tank support frame during operation is 82.45 MPa,which is less than the allowable stress of the material,and the strength meets the design requirements.(5)A field verification experiment was carried out on the round baler machine for silage rice straw designed in this paper.According to the standards of relevant industries,the whole rice straw and broken rice straw were used as the experimental factors,and the field experiment was carried out with the rate of bale formation,the rate of picking loss & the loss rate of bundle and the bundling time as the experimental indicators.The experimental results show that the design of the round baler machine for silage rice straw designed in this paper meets the requirements and the installation layout is reasonable. |
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