Design And Experimental Study Of A Shock Absorbing Air Suction Wheat Precision Seeding Device

Wheat is one of the main food crops in China,with its output ranking first in the world.Currently,wheat seeders mainly use mechanical seed metering devices,which have poor seed metering effect and low seeding efficiency,ultimately affecting the yield of wheat.Compared with mechanical seed metering devices,air suction seed metering devices have the advantages of not easily damaging seeds,high seeding efficiency,achieving single seed precision seeding,and low requirements for seed appearance.Based on the commonly used air suction type seed metering device,a shock absorbing type air suction wheat precision seed metering device was developed in this paper.The bench test has verified that the shock-absorbing air suction wheat precision metering device has the best metering effect when the aperture is 2.2 mm,the rotation speed of the metering disk is 45 r/min,and the negative pressure value is-3 KPa.The qualified rate is 96.24%,the missed seeding rate is 2.18%,and the replay rate is 0.58%.The main contents of this study are as follows:(1)Determination of seed physical properties: Through statistical analysis of the main physical properties of 100 types of wheat seeds,a representative Bainong 207 wheat seed was finally selected as the working object of the seed metering device.Then,the main physical properties of Bainong 207,such as 1000-grain weight,triaxial size,density,moisture content,angle of repose,and sliding friction angle,were measured to provide data support for subsequent structural design and simulation analysis of the seed metering device.(2)Structural design of seed metering device: Solid Works is used to design the overall structure of the seed metering device.The seed metering device mainly includes flange plate,negative pressure chamber rear cover,seed metering disk,seed storage chamber chassis,seed storage chamber upper cover,power shaft,shock absorber,and other parts;The key structures of the shock absorption type air suction wheat precision metering device,such as the metering disk,the negative pressure chamber rear cover,and the shock absorption device,were emphatically designed and studied.(3)Simulation analysis of seed metering device: Fluent software is used to study the impact of factors such as seed suction hole type and negative pressure value on the internal flow field of the seed metering device;Using EDEM software to study the disturbing effect of seed tray assisted seed suction structure on wheat population;Carry out Fluent-EDEM coupling simulation of the seed metering process of the seed metering device to explore the optimal structural dimensions and optimal operating parameters of the seed metering device.(4)Bench test: Using the JPS-12 seed metering device test bench to conduct bench tests with the pass rate,missed seeding rate,and replay rate as indicators.Firstly,a single factor experiment was conducted to determine the optimal parameter range for factors such as the diameter of the seed suction hole,the rotation speed of the seed metering disk,and the negative pressure value.Then,a three factor and three level orthogonal experiment was conducted to explore the best parameter combination that affects the seed metering quality.Finally,a comparative experiment was conducted to explore the impact of the damping device on the seed metering device.