Abstract:A V-groove dialing round type guiding-seed device was designed to improve the uniformity and stability of planting and meet the requirements of precision planting. The overall structure and working principle of the precision guiding-seed device were illustrated and analyzed. The optimal design of structural parameters of key components was conducted, such as guiding curve, V-groove and dialing round. The interaction model of machinery and maize was established by using discrete element method. The scoop-type metering device was taken as the seeding object and EDEM software was employed to simulate the guiding-seed process. And then the dynamic behaviors of maize were researched under the working conditions. Orthogonal simulation experiments were carried out based on numerical simulation technology with forward speed, rotational speed, tangent angle as experimental factors and with qualified index and coefficient of variation as assessment consumption. Based on experimental data, a mathematical model was built, and the experimental factors were optimized by Design-Expert 6.0.10 software, the best combination was achieved. The simulation results showed that as the forward speed was 7.69km/h, rotational speed was 29.47r/min, tangent angle was 46.10°, and the qualified index was 92.05%, the coefficient of variation was 8.00%, which could meet the requirements of precision planting. On this basis, the high-speed photography experiment, comparison performance experiment and vibration adaptation experiment were carried out. The experimental results showed that the majority of grains were slipping in a steady state in the tube and few irregular impacts and tumbling. The V-groove dialing round type guiding-seed device had better adaptability to different maize grains which could be used in conjunction with scoop-type, pickup finger-type and air suction-type precision seed metering device. Its qualified index was similar to that of unguided tube, and coefficient of variation was higher than those of retractable plastic guide tube, curved guide tube and unguided tube. Under the normal operating conditions (vibration amplitude was 1~3mm, and vibration frequency was 1~4Hz), the vibration amplitude and frequency had little effect on the homogeneity of the guided parts.
