Design and experiment of multifunctional integrated seeding opener

Abstract: Sowing opener is one of the key parts of seeders, and its working performance affects the seeding quality. Domestic and foreign scholars have done a great deal of research on sowing openers in terms of traction resistance, soil disturbance, soil return performance and blocking performance. But there are few reports on the research of sowing opener for the integrative structure of ditching, earthing and suppressing. In this paper, an integrated sowing opener, which can be used to ditch, earth and suppress, was designed. It can solve the problems such as large disturbance of soil, insufficient compactness of seed bed soil, and poor uniformity of sowing depth. The combination of its sliding knife, retaining plate and repressing wheel can realize the seeding ditch, the seed falling to the bottom of the ditch, the wet soil returning to ditch, the suppressing wheel suppressing the seeding ditch, and the seed being in close contact with the soil. In this paper, the cutting edge curve is analyzed according to the slip cutting principle. It sets the cutting edge curve equation as parabola equation to deduce the conditions which can satisfy the needs of the slide cutting. That is, the slip angle is larger than the friction angle. The final result shows the range of the slider slip angle is 25°-65°. Based on the analysis of the principle of soil reflux after the operation of the trench opener, it can be seen that the change of the obliquity angle of the retaining plate affects the soil disturbance and the soil reflux, and the range of the inclination of retaining soil plate is 0-12.4°. According to the agronomic requirements, the range of soil compactness required for seed growth is 30-50 kPa, and the spring deformation amount is calculated to be 9-15 mm. Finally, the influencing factors can be determined. They are the slip angle, the slope of the retaining plate and the deformation of the spring. The slider slip angle, inclination of retaining soil plate and deformation variables of spring were selected as test factors. Soil compaction and soil disturbance were selected as experimental indices. The optimal parameter combination of the integrated seeding opener obtained from the soil bin text of optimizing the structural parameters was as follows: The slider slip angle was 44.6°, the inclination of retaining soil plate was 3.2° and the deformation variable of spring was 11.8 mm. In order to verify the operation performance of the integrated seeding opener better, field contrast tests were carried out with a double-disc opener and a sharp angle opener under the optimal parameters. The variation coefficient of sowing depth, soil compactness, soil disturbance and backing soil quantity were selected as test indices. The experimental results showed that variation coefficient of sowing depth of the integrated opener was 6.03%, which was 32.4% lower than that of the double-disc opener and 25.2% lower than the sharp angle opener. When the integrated opener was operated, the seeds fell into the ditch prior to the soil, which improved the seeds depth uniformity. The soil compactness was 38.6% higher than that of the double-disc opener and 62.9% higher than that of the sharp angle opener after the working of integrated opener. The suppression part of the integrated opener suppressed the ditches, after the soil-covering ditches were suppressed again by suppressing wheels of the seeder, which increased the soil compaction of the seed bed. The amount of soil disturbance generated by the integrated opener was 16.3% lower than that of the double-disc opener and 36.5% lower than that of the sharp angle opener. But its backing soil quantity was 29.9% higher than that of double-disc opener and 61.5% higher than that of sharp angle opener. Therefore, the integrated opener has little disturbance to the soil. In general, the integrated opener can improve the seedbed environment, enhance soil compaction and improve the uniformity of seeding depth. Besides, this type opener provides an integrated reference for the design of sowing openers.