Design of Pneumatic Hole Seed Metering Device for Precision Direct Seeding Component of Leafy Vegetables

In view of current situation that traditional seed metering device is difficult to achieve precision sowing due to small particle size，large sowing amount and irregular shape of leafy vegetable seeds，a kind of pneumatic hole seed metering device for precision direct seeding component of leafy vegetables was designed.The seed metering device adopted combined seed metering principle of positive and negative air pressure，which could simplify structure and quantity of seed metering device of planter，and improve working efficiency and quality of seed metering device.Performance test results showed that when suction nozzle suction time was 1.0 s，air blowing suction nozzle time was 0.3 s and air needle cleaning time was 0.3 s，comprehensive performance of productivity，replay rate and hole rate were the best，which were 12 800 holes per hour，3.98% and 3.95% respectively.