| China is a big country in rapeseed production.The middle and lower reaches of the Yangtze River are the main areas for rapeseed production and planting in China.However,the climate in the middle and lower reaches of the Yangtze River is diverse,and the farming methods vary greatly,and the soil hardening and ploughing are caused by many years of water and drought rotation.The problem of soil compaction is serious.The farming method affects the physical properties of the soil,which in turn affects the yield of rapeseed.Reasonable farming is a means to create a good soil layer structure and an important guarantee for high yield of rapeseed.Therefore,the research on different tillage methods,the best tillage mode is preferred,and the operation process and rapeseed sowing machine in this mode are studied.It is found that the current rate of broken soil is generally not high,and the rotary tillage operation is serious,and most of them adopt the general profiling method,which is easy to cause inconsistency in broadcasting depth and uneven distribution of temperature and light resources.This thesis takes the rice oil tanker in Gaochun District,Nanjing City,Jiangsu Province as an example,and conducts experimental research on different methods of tillage and returning to the rapeseed season.Based on the model,the rotary tillering device and seeding monomer of the rotary tillage planting equipment are designed.The simulation analysis and field experiment verified the operation effect,and the test proved that the machine was suitable for rotary tillage in rice oil rotation area.The main research contents of this thesis are as follows:(1).In the Gaochun District of Nanjing,using different farming modes and different straw returning methods as the factors,the hybrid orthogonal positioning test was carried out,and the tillage method of ploughing+rotary tillage and rotary tillage was compared,and the total amount of straw was returned to the field and the straw was partially The effects of three fields of returning fields on the soil physical properties and rapeseed yield were analyzed by the range analysis.The results showed that the tillage method had a significant effect on the soil bulk density of the cultivated layer,and the straw returning method affected the yield of rapeseed.The main influencing factors,with rapeseed yield as the main index,the selection of rotary tillage straw was returned to the field as the optimal tillage mode.Under the optimal mode,the main soil physical index before rapeseed was the soil bulk density of 1.29-1.32g/cm3..The soil moisture content is between 23-25%,the average soil compaction of the plough layer is 401-557KPa,the maximum soil compaction is 1035-1087KPa,and the tillage depth is 13-17cm.(2).In order to increase the rate of rotary tillage and achieve the requirements of rotary tillage of rapeseed,rotary rotation was carried out at a speed of 1 m/s under conditions of paddy soil with a water content of 23%at 250 rpm,270 rpm and 310 rpm.According to the experiment of the effect of rotary tillage after operation,the rates of rotary tillage at 6 rpm were 65%,77%and 80%,respectively.The power required for calculation of 270 rpm and 310 rpm with higher soil efficiency was 46.34 kw and 50.94kw,the 270 rpm with high power and small soil rate is selected as the rotary cultivating speed.The IIT225 rotary tiller is selected as the rotary cultivating blade,and the knives are arranged by the outward mounting method.(3).Based on the ditch depth stability and soil disturbance as the index,the comparison test of the ditching effect between the double disc opener and the single disc opener is carried out.The test firstly compares the different installation modes of the single disc to the ditch stability.And the influence of soil disturbance is analyzed by the range analysis.The installation method suitable for rapeseed sowing is compared with the double disc opener for trenching effect.The test results show that when the soil moisture content is 23%,the unit dish opener groove depth The stability is 95%,the soil disturbance is 12%;the double disc opener groove depth stability is 96%,the soil disturbance is 12%,and the double disc opener is used as the seed trench trenching device.(4).Using computer-aided analysis software to analyze the effects of rotary tiller shaft and rotary tillage.Using SolidWorks and Catia software to complete the 3D modeling of key components;using ANSYS to analyze the vibration mode of the rotary cutter shaft,the critical speed of the cutter shaft is 3126.1-18379.8 rpm,and the speed of 270 rpm is selected to meet the engineering design requirements.Under normal working conditions.There will be no damage.The edem discrete element analysis software was used to analyze the backfilling rate of the rotary tillage ditching device.Under the condition of 25%water content of paddy soil particles,the soil backfilling rate was 85%.(5).Through the field test,the working condition of the machine under the actual working conditions can meet the requirements of the machine operation.The machine was tested in the field of sorghum rice oil tanker on October 6,2018.The test soil was paddy soil,the soil moisture content was 27.6%,the soil bulk density was 1.15g/cm3,and the depth of the tillage and the stability of the ploughing depth were tested.The results of field trials showed that the planting depth was 14-15cm,the depth of ploughing was 87%,and the rate of soil breaking was 75%.The depth of single groove was 30mm and the stability coefficient was It is 80%.The rapeseed season rotary tillage+straw returning to the field has effectively improved the yield of rapeseed and improved the soil condition.The designed rotary tillage plant has the characteristics of high stability of seed furrow and high rate of rotary tillage.Requirements for rotary tillage,trench ditching and single trenching can be completed at the same time. |
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