The Design And Experimental Research On Seeding Mechanism Of The Japonica Rice Directional Seed Metering Device

China is a large agricultural country.Rice is the main food crop for nearly 60% people and one of the most important food crops in China.Rice was also widely grown in China.The mechanization of rice planting in our country has been increasing year by year with the development of science and technology.It not only improved the efficiency of rice cultivation,but also liberated manpower and reduced the cost of rice planting.Transplanting with machine was the key technology of mechanization of rice.While the rice seedling mechanization not only has an important influence to the mechanization of rice planting,but also was the precondition of mechanical transplanting.Precision seeder was the core components of rice seedling sowing equipment in the process of rice dry nursery planting.The sowing quantity and sowing uniformity of the precision will affect seedling quality and operation effect of subsequent transplanting.Therefore,it was of great significance to study a kind of seed metering equipment with high precision and stable operation.Japonica rice directional seed metering device was a machine which in order to solve the problem of uneven seeding in low seeding condition.It would influence the seeding performance of Japonica rice directional seed metering device for sprouting seeds,because of its poor mobility and difficult to separation.In this paper,designed a kind of multi metering seeding device was designed based on the research and development of Japonica rice directional seed metering device.Studied the multi metering seeding device through the study of literature,theoretical analysis,institutional design,EDEM numerical simulation,single factor and multi-factor experiment.The main research contents and main results are as follows.(1)Designed a kind of multi metering seeding device was designed.The overall structure and key components were determined.The stress analysis was analyzed on the guide vertebral body.The three dimensional models of the seeding mechanism were built in this paper.(2)Simulated the working conditions of the seeding mechanism were simulated by discrete element software EDEM.The japonica 88 was used as the simulation object.The particle model was established and the contact model between the particles and the device was determined before the simulation.The simulation results show that when the disc speed is between 70-90 r/min interval,and the width of the disk is selected from the range of 9-11 mm and the diameter of the disc is 200-220 mm,the total capacity of the multi metering seeding device.(3)Experimental study on the seeding mechanism.Single factor test and three factors and five levels orthogonal rotation combination test were used in the study on the seeding mechanism.Experimental results showed that the order of the factors which affect the total number of the seeding mechanism was seed mouth opening > disc speed > disc diameter.The order of the factors which affect the variation coefficient of the seeding mechanism was disc diameter > seed mouth opening > disc speed.A set of optimal solutions were obtained that the disc speed was 89.95 r/min,the disc diameter was 217.52 mm,seed mouth opening was 9.25 mm and then the equations were combined and optimized by Design-Expert8.0.5b software.At this time,the total number of the seeding mechanism was 262 grains,the variation coefficient of the seeding mechanism was 14.39%.(4)Optimal design and test verification of the seeding mechanism were conducted in this paper.Contrast test was conducted after using the new kind of seeding device for the Japonica rice directional seed metering device.Contrast test was conduct after using the new kind of seeding device for the Japonica rice directional seed metering device.The test results showed that the qualified rate and the qualified rate of the ideal has been increased and the working performance has been improved.While the leakage rate and the replay rate were reduced correspondingly.The qualified rate and the qualified rate of the ideal were improved respectively by 0.78% and 5.01%,and the leakage rate and the replay rate were reduced by 0.45% and 0.33%.The test results showed that the working performance of the Japonica rice directional seed metering device has been improved.The research in this paper improved the working performance of the Japonica rice directional seed metering device,and also provided new ideas and methods for the supply of rice.The research in this paper also promoted further development of the mechanization of rice seedlings.