Design and experiment of the pressing wheel profiling ditching device for sowing panax notoginseng to grow seedlings

Abstract: Aimed at the requirements of mechanized sowing of panax notoginseng to grow seedings, the relative researches of panax notoginseng precision planter have been carried out. However, there is no suitable sowing planter for panax notoginseng, and the traditional artificial planting mode take advantages at present. As a result, the labor cost in the sowing season is high and the sowing quality is uneven. The ditching device is an important working part of the planter, because the uniformity of row spacing, plant spacing and ditching depth stability are directly affected by its ditching quality, then the germination and growth of seeds are also affected. The existing ditching device still had the following disadvantages: the ditching depth stability was uneven, the returned amount of soil was large and the soil compaction at the bottom of the seed ditch was insufficient, that would affect the quality of ditching. To solve the existing problems and satisfy the special planting agronomy with small row spacing, small plant spacing and shallow sowing depth at the time, a kind of pressing wheel profiling ditching device was designed according to the principle of two force lever. With the advance of the planter, the pressing wheel rolled forward while pressing out the seed ditch under the gravity of itself and the pressing wheel connecting plate. The device was suitable for sowing of panax notoginseng to grow seedlings, which not only completed the ditching, but also realized the horizontal and vertical profiling, and had a certain compaction effect on loose soil. In other words, it adopted profiling technology and multifunctional combination method, and realized the integrated functions of profiling, ditching and proper compaction of ditch bottom. With the help of ANSYS software, the stress and strain analysis of pressing wheel connecting plate was carried out to verify the reliability of pressing wheel profiling ditching device. According to the analysis of pressing wheel profiling ditching device and related research, took soil compaction, planter forward speed, spring pretension as test factors, and ditching depth stability as test indicator to carry out a quadratic orthogonal combination test of three factors and five levels. Through the F value test, the order of main factors affecting the ditching depth stability was the planter forward speed, soil compaction and spring pretension. Used Design Expert 10.0.3 software to analyze the response surface of the experimental factors and optimized the parameters with the optimization function, regression mathematical model between test factors and ditching depth stability was established, and significance test was conducted. The ditching depth stability was 89.41% under the optimal working parameters with soil compaction 259.50 kPa, planter forward speed 6.40 m/min, spring pretension 211.90 N. The soil trough test with the optimal working parameters was used to verify the credibility of the analysis results from data processing software. The test results showed that the average ditching depth stability of test basically agreed with the solution of the optimization model. Good ditching depth stability indicated that the study could provide a reference for the design of ditching device for sowing panax notoginseng to grow seedings.