Structure Optimization And Experiment On Air-suction Cylinder Precision Seeder

Precision seeding is attached importance to by all over the world, for it can save a lot of seeds and much time to plant them and increase the output. Basing on researching domestic and foreign air-suction cylinder precision seeder , a new type of air-suction cylinder precision seeder was designed and manufactured .There are some merits of the seeder: First, the main shaft with two cavums was optimized which reduced the abrasion and prolonged the life of the bearings. Second, the spring structure was adopted , so the gas leakage between the plastic board and the seeder's wall was eliminated because of friction. Third ,the seeds box was vibrated that availed picking up seeds.Basing on the air-suction cylinder precision seeder, the research was done as follows:1. Seed pickup and seed ejection were theoretically analyzed and mathematical models of pickup force,pickup distance,release error,impact angle and impact velocity were deduced.2. ANSYS finite element analysis software was used to develop the model and simulate the air flow distribution of the sucking holes ,positive and negative cavums. The results showed that the performance of straight holes were better than conical holes and countersunk holes; the bigger of the diameter of the holes ,the better of their sucking effect, but the distance of air travelling had nearly no influence to sucking effect; the holes which were close to the air flow in the wall of the drum-seeder were influenced notably.3. Experiments were done on the seeder, especially on the types and diameters of the sucking holes,the pressure of sucking holes,the vibrating frequency of seeds box and rotating speed of the roller. The experiment datum were dealt with by DPS software. Through analysis of extreme difference and variance , the primary and secondary sequence of the factors influencing the experiment were found, the best parameters were also found. 4. Quadratic polynomial regression analysis was used to analyze the relationship between the single seed rate , vacancy rate and the influence factors .Take the rape seeds for example,the experiment showed that the single seed rate could reach 92%,vacancy rate could reach 4% with conical holes with diameter 1mm,the pressure of sucking holes 2kPa,the vibrating frequency of seeds box 80Hz and the rotating speed of the roller 14r/min.Through computer simulation , theoretical analysis and experiment research, some laws useful for practical application were found.