| Guizhou Province has a good ecological environment and rich biological resources.It is one of the main producing areas of Pinellia,and it is currently the largest Pinellia production area in the country.The output of Pinellia accounts for one-third of the national Pinellia market.In recent years,the price of finished Pinellia has stabilized between 100yuan·kg-1～120 yuan·kg-1,which can bring more than 1 billion yuan of income to the production area of Pinellia sinensis in Guizhou every year,which greatly helps the local poverty alleviation.Work.In order to ensure the quality of Pinellia,the production area of Pinellia in Guizhou adopts a wild planting model to plant Pinellia,that is,no weeding operations are performed during the growth of Pinellia,and a high-density planting mode is used to suppress the growth of weeds and ensure yield.Due to the complex geographical environment and unique planting methods of Pinellia in Guizhou,there is currently no equipment suitable for sowing Pinellia in Guizhou.Therefore,the planting of Pinellia in Guizhou is manual work,which is labor-intensive and labor-intensive,resulting in the high cost of Pinellia planting.In order to save labor and reduce costs,and promote local growers to increase production and generate income,this paper combines the agronomic requirements of local Pinellia planting,adopts the research methods of theoretical analysis,simulation test,structural optimization and bench test verification,and designs and develops a suitable for Guizhou.Pinellia sowing planter for regional Pinellia planting.The specific research work carried out in this paper is as follows:1)Completed the determination of parameters such as triaxial size,moisture content,density,bulk density,Poisson’s ratio,elastic modulus,shear strength,ultimate compressive strength of Pinellia seeds at the sowing stage in Guizhou,and at the same time,the parameters of Pinellia seeds were measured.The damage analysis was carried out,and it was found that when the pressing force exceeded 100N,the pulp tissue inside the seeds of Pinellia ternata would be broken;By consulting relevant literature,it was found that the seeds with the equivalent diameter of about 10 mm had the highest reproductive coefficient,the sowing surface width of 800 mm,and the planting density of 1800-2250 kg·hm-2had the highest yield.The above work can provide important parameter basis for the subsequent design and analysis of the seed metering device and the uniform distribution mechanism of the Pinellia sowing planter.2)After understanding the agronomic requirements of Pinellia planting,the working principles,advantages and disadvantages of the existing sowing and sowing devices were compared and analyzed,and the suitable sowing and sowing device was selected,that is,the evenly divided plate sowing device.Referring to the working principle of the evenly divided plate sowing device,the overall structure of the Pinellia sowing planter is designed,and the key components of the Pinellia sowing planting mechanism are theoretically analyzed.The structure model of the whole machine is established through Solid Works2016.Design and manufacture a seeding conveyor belt with hemispherical staggered seed filling holes.The maximum diameter of the seed filling holes is 17mm and the depth is 4mm.Asymmetric structure of the seed box,and found that the front and rear bottom plates of the seed box have a significant effect on the extrusion force of the seeds in the seed box and the flow properties of the seeds in the seed box;In order to achieve uniform and fast sowing and seeding,and at the same time minimize the damage rate of the uniform shunt mechanism to the seeds,a second-order surface uniform shunt mechanism was designed,and the installation angle of the shunt mechanism,the length of the transition section of the second-order surface,the radius of the first-order surface,the second-order surface,and the The radius of the step surface has a significant effect on the spreading effect of the uniform distribution mechanism.3)In order to shorten the design cycle and reduce the cost of research and development,the EDEM discrete element simulation test was used to optimize the design of the optimal parameter structure of the key components of the Pinellia seeder.Due to the lack of the relevant parameters required for the discrete element simulation of Pinellia,the relevant parameters required for the discrete element simulation of Pinellia were obtained through practical experiments combined with simulation experiments and literature review,and finally Pinellia-Pinellia and Pinellia-Stainless Steel were obtained.,Pinellia-PVC belt,Pinellia-soil collision recovery coefficients were 0.472,0.636,0.587,0.020,static friction coefficients were 0.554,0.615,0.800,1.240,rolling friction coefficients were 0.157,0.150,0.180,1.240.4)After obtaining the parameters required for the discrete element simulation between Pinellia and the contact material during the sowing process of the Pinellia sowing planter,the best flow performance of the seeds in the seed box and the seeding conveyor belt for the seeds in the seed box are obtained.The optimization goal is to minimize the maximum extrusion force of the Pinellia seeds above.The structure of the seed box is simulated and analyzed by EDEM software and the structure is optimized.Finally,the inclination angleβof the current side bottom plate is 50°,the inclination angleαof the rear bottom plate 1 is40°,When the inclination angleθof the rear bottom plate 2 is 40°,the total pressure on the seeding conveyor belt is at least 15.74 N and the average number of particles in the virtual grid is at most 23.64.Taking the best spreading uniformity as the optimization goal,the uniform shunt mechanism is optimized by the same method,and finally the installation angle is 62°,the length of the transition section of the second-order surface is 212mm,the radius of the first-order surface is 1573mm,and the radius of the second-order surface is1573mm.When the diameter was 2903 mm,the uniform distribution effect of the uniform distribution mechanism was the best,and the average lateral uniformity coefficient of variation of the seeds distributed on the 800 mm wide seed bed was 3.37%.5)In order to verify the rationality and accuracy of the optimal parameters of the structure of the key components of the Pinellia seeder,the working performance of the Pinellia seeder was tested by building a bench test,and the seeding stability and sowing uniformity were used as the Pinellia The evaluation index of the sowing planter,it was finally measured that the seeding motor speed of the Pinellia sowing planter was strictly positively correlated with the seeding rate,indicating that the Pinellia sowing planter had strong seeding stability;At the seeding rate of 44.92g·s-1,the seedbed was moved at a rate of 1km·h-1,the number of seeds in each inoculation slot on the seedbed was counted,and finally the average horizontal distribution of Pinellia seeds in a width of 800mm was calculated.The coefficient of variation of uniformity is 3.71%,and the relative error between the coefficient of variation of lateral uniformity of 3.37%obtained from the simulation test is 0.10%,and the relative error is extremely small,indicating that the structural parameters of the uniform shunt mechanism for the second-order surface determined by the simulation test are reasonable and effective.The average seeding rate per square meter is 212.57g,which meets the requirements of Pinellia sowing.The bench test proves that the indexes of the Pinellia sowing planter meet the design requirements and achieve the design goals. |
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