Design and Experimental Research of a Rice Precision Seeder for Plug Seedlings

Abstract. The precision seeder for plug seedlings is regarded as the key equipment of industrial seedling technique. According to the planting agronomic requirements in the greenhouse plant industry a new rice precision seeder was developed and evaluated to improve the sowing performance.The device consists of reciprocating driving mechanism,vacuum parts,and a virbrating components.The reciprocating driving mechanism connected with the vacuum parts consists of a crank,a connecting rod and two parallel equal rocker,which generates an appropriate path. The design and virtual simulation results showed that the maximum limit angle of the rocker, the minimum limit angle of the rocker, the swing angle and pickup time were 139.44°, 68.4°, 71.04°and 0.43s, respectively when the length of crank, connecting rod and rocker were 58mm, 389mm and 200mm, respectively. The reciprocating driving mechanism can satisfy the design requirements of high pickup and low release and presents good dynamic characteristics and force transmission characteristics. The pickup performance was tested.The results showed the rate of picking up one seed was 95% ,while the rate of miss-seeding was less than 3% when the vacuum nozzle diameter, pickup vacuum pressure, angular velocity of the crank and the vibrating frequency of the virbrating components were φ2.0 mm, 12kPa ,30r/min and 22.5Hz ,respectively. The precision metering device has good sowing performance, meeting the requirements of a rice precision seeding.