Design And Experimental Research Of Rice Direct Seeding Slot Seed Metering Device

The direct seeding of rice saves the tedious links such as seedling raising,nursery pulling and transplanting.It is the simplest planting way in the light cultivation technique of rice,and the planting way adapting to the international development trend.It has high work efficiency,low labor intensity,low material consumption,and convenient operation as well as a broad space for development.This article describes the design and test of a kind of seed-metering device of roller feed of paddy seeder for rice buds,and carries out related theoretical analysis and bench tests.The main research work of this article is as follows:Ⅰ.Test on properties of the bud of broken breast in rice.Ⅱ.The working principle of the seed-metering device and the choice of the main structural parameters.Ⅲ.The slot form of 4 kinds of roller feed seed-metering device is designed——semicircular slot,V-shaped slot,trapezoidal slot,and hook-shaped slot.Thought theoretical analysis and orthogonal simulation test of the EDEM seed-metering process,finally the hook-shaped slot is determined.Ⅳ.Theoretical analysis was performed on the process of seed filling,seed clearing and seed protection of seed-metering device.During the seed filling process,the situation of the seed approaching the slot and filling the slot hole was analyzed.The limit seeding speed was determined.The limit speed of seed filling was related to the helix angle.Under other conditions unchanged,the helix angle increased,the limit relative filling rate also increases,which is beneficial for seed filling.The mechanical model of the seed in the corresponding stage was created from several aspects such as seed filling,seed clearing,seed protection,etc.,and the force analysis was carried out for the roller feed at the stage of seed filling,seed clearing and seed protection.Ⅴ.Using the JPS-12 test stand,the single-factor and multi-factor orthogonal tests were conducted.The pass rate of hole diameter,the pass rate of the number of holes,and the damage rate of buds of the roller feed seed-metering device were used as test indicators.The final regression test results showed that:When the helical angle of slot wheel groove hole x₁=13.46°and the rotation speed of slot wheel x₂=21.09r/min,the performance of seed-metering is optimal.The pass rate of hole diameter y₁=97.89%,the pass rate of hole grain number y₂=96.33%and the damage rate of bud y₃=5.32%,which can meet the agronomic requirements of direct seeding of rice.The research in this article lays the foundation for the further development of precision planter for rice buds and other crops.