Technical features of main working parts
The working parts of the seeder include seeding device, fertilizer dispenser, furrow opener, seed delivery tube, soil covering and pressing device, etc.
(1) Seeder. The seeding device continuously and evenly discharges seeds from the seed box according to the sowing requirements. Grain drills often use an outer groove wheel seeding device. There are 10 to 12 axial grooves on the cylindrical surface of the outer groove wheel. During operation, the seeds fill the seeding cup and the groove of the groove wheel by their own weight. When the outer groove wheel rotates, the groove wheel forces the seeds to be discharged from the bottom of the groove wheel, which is called the lower discharge. Because the seeding groove wheel can move laterally, the seeding amount can be adjusted by changing the outer groove wheel speed and the working length of the outer groove wheel in the seeding cup. The outer groove wheel has two specifications (large and small) (different diameters). When using a small groove wheel to sow small seeds, the speed can be appropriately increased, and its seeding uniformity is slightly better than that of a large groove wheel. The gap between the outer groove wheel and the seeding tongue is adjustable to meet the needs of sowing large and small seeds. On some seed drills, when sowing large seeds, the outer groove wheel rotates in the opposite direction, and the seeds are discharged from the top, which is called the upper row.
(2) Fertilizer discharger. The horizontal star wheel fertilizer discharger consists of a fertilizer discharge star wheel and a hammer. When the star wheel teeth rotate, the fertilizer is brought to the fertilizer discharge port, and the hammer hits the fertilizer to make it fall into the fertilizer delivery pipe.
(3) Furrow opener. The function of the furrow opener is to open furrows, guide seeds into the soil, and cover wet soil. The seed drill generally uses a double disc furrow opener, with the two disc blades intersecting at a point at the front and bottom, forming an angle (usually 9° to 16°). When working, under the action of their own weight and additional spring pressure, the two discs roll forward, cut the soil and push it to both sides, and open a seed furrow. The seeds and fertilizers fall into the bottom of the furrow through the seed guide pipe in the middle of the furrow opener body. After the disc passes, the wet soil at the bottom of the furrow wall covers the seeds, and then covers them with dry soil. Some small low-speed grain seed drills use a hoe-type furrow opener. The hoe-type furrow opener has the characteristics of simple structure, light weight and easy manufacturing, but it is easy to get caught by grass, soil accumulation, and mixing of dry and wet soil.
(4) Seed (fertilizer) pipe. Installed between the seed meter and the furrow opener, it guides the seeds discharged by the seed meter to the furrow opener. The roll-type seed pipe is made of steel belt, which can be stretched and bent, and the seed guidance is reliable.
(5) Soil cover. It is used to cover the seeds sown in the seed furrow with soil. The pressure device is used to compact the soil so that the seeds are in close contact with the wet soil.
