| Wheat is one of the most important food crops in the world.Its total area,total output and total trade volume are in the forefront of food crops.The population with wheat as the main food in the world accounts for 1/3 of the total population in the world.At present,the problems of poor operation quality,poor stability of sowing depth and low degree of duplex operation exist in China’s wheat sowing machinery,which directly lead to high production cost and low yield of wheat.In this paper,aiming at the problems of wheat seeding machinery,a wheat seeding test bench was designed.Aiming at the accuracy,dispersion and uniformity of seeding,and according to the requirements of different seeding rates,the moving speed of the machine,the rotation speed of the seed metering device and the height above the ground were optimized.Combined with the optimization parameters,a double axis rotary tillage groove pressing sowing,ditching and even covering soil machine was designed Comparison test.The main research work and achievements are as follows:(1)The simulation test bench of wheat sowing was designed and constructed.Taking the accuracy,dispersion and uniformity of sowing as the sowing quality indexes,and the traveling speed,the rotation speed of seed metering device and the height above the ground as the three main factors affecting the sowing quality,the comparative experiments of the influence of the tubeless and the tubeless on the sowing quality were carried out.The results showed that the tubeless sowing quality was significantly better than the tubeless sowing quality The seeds were sown in the same way.(2)Using single factor test and orthogonal test theory to analyze,through origin to preliminary analyze the test data,and then using design expert and MATLAB to optimize,the optimal parameter combination of three factors under different seeding rate is obtained:the optimal value of the moving speed of the machine is constant 0.80 M/s,and the optimal range of the metering speed is 17.5～23.53 M/s The optimal range of height above ground is 8.12～8.56 cm.(3)In this paper,the design and working principle of the double axis rotary tillage and pressing groove sowing and ditching machine were studied,and the transmission efficiency of the machine was analyzed.The transmission efficiency of the machine was 0.716.The key component of the machine,the groove pressing wheel,is designed and analyzed.The groove pressing wheel can stably open a seed groove with a width of 5 cm and a depth of 1-3 cm.The device is divided into left and right sides,which can improve the smoothness of soil,assist the stability of seed tank and ditch,improve the soil coverage of seeds,and improve the quality of sowing.A soil cleaning device is also designed,which is divided into left and right auger mechanisms.(4)The results show that the accuracy,dispersion and uniformity are 88.67%,45.45%and 73.74%respectively.The results show that the seeding depth is relatively consistent,the effect of the uniform soil covering device of the prototype is obvious,the consistency of the seeding soil covering thickness is realized,the measured seedling rate is 91%,the seedling growth and development is significantly better than that of the ordinary seeder,and each sowing evaluation index can meet and higher than the requirements of the general wheat sowing standard. |
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