Manufacturing And Experimental Research On Small Grain Precision Seeder

Sowing is the precondition of agricultural development. But, nowadays, the sowing of small seed crop still exists the problem of seeds breaking, seeding device plugging, unstable seeding performance, and low working efficiency. So decreasing the number of breaking seeds and improve the sow performance is a research importance in this stage. This study, according to small size, light weight and other features of small seeds, design a new reasonable and feasible mechanical seed metering device with cam push rods, and manufactured the first generation of self-propelled Precision Seeder with a simple structure and convenient manipulation.This essay includes:(1) Completed a new cam pusher seed metering device design. The theoretical basis is the features of mechanical seeder,the structure and working principle of cam push rods mechanism. Combined with the characteristics of tobacco seeds, small seed precision seeding device design scheme was determined. Introduced the working principle of the precision seeding device, which character is cam push rods can push the seed out from hole under the action of a spring.(2) Parameter determination and discrete element analysis of seeding device. In this study, the influence of seeding hole shape and seeding wheel speed is analyzed, seeding wheel diameter is 90 mm, the width of seeding wheel is 20 mm.there are six holes around the seeding wheel, the diameter of these holes are 2.5mm, the depth of these holes are 2.5 mm. Base radius of cam is 21 mm. Pushing motion angle is 23 degrees; nearest dwell angle is 262 degrees, motion angle for return travel is 45 degrees, farthest dwell angle is 30 degrees, the distance of push rod travel design is 3mm.(3) Performance test of seeding device was completed. The test consists of two parts: one is the single factor test, the other is seed spacing uniformity test. The results indicate that with the increase of rotating speed, the leakage sowing rate increased first and then decreased, The reseeding rate gradually increased. Damage rate increased gradually. In the case of seeding device rotating speed is not higher than 19r/min in the test, the leakage sowing rate was less than 3.11%, the reseeding rate was less than 1.4%, seed damage rate was less than 3.5%, Seed spacing passing rate is above 90%. So the seeding device can satisfy the requirements of tobacco seeding.(4) Seeding device design and test. Follow the small grain crops grow agronomic requirements, and combined with previous studies seeder data, the small grain precision seeding device was designed and manufactured. The results indicate that when the seeding device is in a low speed, the effects of seeding with a guide tube is better the situation that there is no guide tube. Because of the defects of the first generation prototype, the precision of seeding is not accurated enough. but This prototype can basically satisfy the requirement of the tobacco seeding. And the seeding device also needs some further improvement.