Performance experiments of bowl dish precision seeder for rice in filling processing

Abstract: Bowl dish precision seeder for rice mainly includes a filling process and a dropping process. In the course of sowing, rice was filled into shaped hole at first, and fell into trays finally by flap driven. In filling process, there are differences in physical characteristics among rice, feature of bud easily injured and interactive effect of structural parameters that create some difficulties in determining the optimal structure parameters.According to commonly data used in production and previous test results, there are three main factors: the diameter of the shaped hole, the thickness of shaped hole and seed boxes velocity that impact filling performance. In order to optimize the parameters of rice bowl dish precision seeder, and improve its filling performance, on condition that brush seed wheels diameter is 78 mm, brush seed wheels high is 3 mm, shaped hole center distance is 19.3 mm, seed box wide is 342 mm, shaped hole is round, rice varieties is kongyu131, bud length is 1-2 mm, rice length 7.0-7.4 mm, rice wide is 3.6-4.0 mm, rice thickness is 2.3-2.6 mm, selected shaped hole diameter , shaped hole thickness and seed boxes velocity as experimental factors, selected filling rate, hole rate and damage rate as performance indicators. The model was established considering nonlinear regression between shaped hole diameter, shaped hole thickness and seed boxes velocity and filling rate, hole rate and damage rate using self-developed rice bowl dish precision seeder by quadratic orthogonal rotary experiments. The method can overcome the shortcomings of the conventional orthogonal experiment. Statistical analysis by computer, and simulation optimization, identify the best combination of the multiple factors and trends. The research results can provide a reference for the design and performance improvement of a rice bowl dish precision seeder.The experimental results showed: 1) the influences of shaped hole diameter, shaped hole thickness and seed boxes velocity on the rate of filling and the rate of cavity were investigated. The results showed that the research results can provide a reference for the design and performance improvement of a rice bowl dish precision seeder; 2) When brush seed wheels diameter is 78 mm，brush seed wheels high is 3 mm, shaped hole center distance is 19.3 mm, seed box wide is 342 mm, shaped hole is round, rice varieties is kongyu131, bud length is 1-2 mm, rice length 7.0-7.4 mm, rice wide is 3.6-4.0 mm, rice thickness is 2.3-2.6 mm, the sequences of factors, which influence the rate of filling and the rate of cavity were shaped hole diameter, shaped hole thickness and seed boxes velocity, and that influenced the rate of damage rate was shaped hole diameter, seed boxes velocity and shaped hole thickness. Optimal parameters of rice bowl dish precision seeder were as abstained that shaped hole diameter was 10mm, shaped hole thickness was 4mm, seed boxes velocity was 0.115 m/s via optimizing the hole diameter, shaped hole thickness and seed boxes velocity; 3) main performance indicators were filling rate 94.81%, damage rate 0.479%, cavity rate 0.46% under the better combinations of process parameters conditions by experimental verification under the same conditions.