| Based on the southern paddy field of no tillage weeds straw treatment machine,its main role is to cut the straw weeds in the no tillage paddy field into the paddy field to conserve moisture and reduce the loss of energy.Straw returning to the field,not only has the effect of increasing production in the stage of cultivating fertilizer,but also has a very obvious follow-up effect,which will play a role of sustainable development.Rice development in paddy fields in South China has great regional comparative advantage.However,the rice and wheat rotation areas in the southern paddy field have one season of water and one season of drought each year,and the amount of straw returned to the field is more than one time higher than that in the northern area.The burning of straw by farmers has become a major public hazard.Compared with the north,the soil moisture content is high and the mechanical walking is easy to sink,which makes the mechanized conservation tillage technology in rice and wheat rotation area more complex and more difficult.The machines and tools designed in this paper are prepared for planting.At present,the paddy fields in South China are for transplanting and live broadcasting.Therefore,the design of the press and cut grass machine needs to meet the planting conditions,so the research and design of the no tillage weed straw treatment machine in paddy field is of great significance.In this paper,the basic parameters of soil and soil experiment were tested in the south of China.Therefore,the equipment of straw and weed treatment was designed.The utility model is suitable for the weed straw machine of paddy field with high moisture content and stubble retention.The resistance,disturbance to the soil and the flatness of the surface after the ditch are analyzed and compared.It not only proves that the designed weed straw treatment machine has a good effect on the grass pressure,but also proves that the longitudinal grass pressure tool has a good effect on the ditch,and also verifies the establishment of the edem software The rationality of soil discrete element simulation model.The main contents are as follows:(1)In this paper,the physical and mechanical properties of the paddy soil in the south of China were measured and tested.The properties of soil and the parameters needed for simulation,such as soil moisture content,density and internal friction coefficient,are obtained.Through the preliminary experiments and soil parameters,the preliminary idea of the design of the grass pressing tool was obtained.(2)The design of weed straw treatment equipment.According to the idea of soil test and the property and agronomic requirement of paddy field in South China,the vertical grass pressing and ditching cutters with regular pentagram,hexagon star and Luo triangle are designed,and the transverse grass pressing cutters with angles of 30 °,50 ° and 60 ° are designed respectively.The structural parameters and motion parameters of the weed straw treatment machine are determined,and the strength of the cutter is checked with ANSYS Workbench,and so is used Lidworks has made three-dimensional modeling.(3)Discrete element simulation and analysis of the weed straw treatment machine were carried out.(1)Firstly,the discrete element contact model suitable for the paddy soil is established,and the simulation parameters of soil particles are set up.(2)The results of the comparative simulation test of the weed straw treatment machine show that the use effect of the Lelo triangle longitudinal compression cutting tool is the best.The disturbance coefficient to the soil is small,and the flatness of the surface is good after the ditch is opened.After the working process reaches a stable state,the horizontal resistance of the machine tool is also the smallest,within the range of 50N-69 N.(3)In order to study the level of the factors,the types of the longitudinal grass pressing tools,the angle of the transverse grass pressing tools and the forward speed of the test-bed connected with the direct seeding machine are taken as the indexes.The results show that there is interaction between experimental factors and indicators.(4)The design expert v8.0.6.1 software is used to analyze the response surface of the simulation test data respectively,and the regression model is obtained,and the correlation among the factors is obtained according to the regression.The results show that the average resistance increases with the increase of the forward speed,and increases with the increase of the tool angle.From the comparison of the three surface figures,it can be seen that under the same factors,the work resistance of the Rilo triangle longitudinal grass pressing tool is the least.(4)The rationality of the simulation model selection and parameter setting was verified by the field test of the grass pressing tool.Through the comparative analysis,it is found that the simulation results of the working resistance of the weed straw treatment machine are basically consistent with the change trend of the test results,and the grass crushing rate is high.For the straw weed treatment,the soil moisture conservation treatment also has a good effect.The results show that the designed equipment can meet the requirements of straw treatment,reduce the resistance and disturbance of soil,and achieve the effect of no tillage. |
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