The Mechanism And Experimental Study On Hole-pricking Mechanism With Planetary Bezier Pitch Curve Gears

Deep-fertilization technology of liquid fertilizer is a kind of agricultural technology which can apply liquid fertilizer accurate quantitatively in deep soil near the roots of crop according to the distribution characteristics of soil nutrient and crops. Practice shows that, the technology is an effective agricultural technical measure which can increase production while reduce consumption, having effects such as reducing fertilizer,improving the utilization, operating cost savings, increasing crop yields and reducing environmental pollution, etc.Currently, there are more liquid fertilizer production enterprises in domestic and foreign, but there are less research on liquid fertilizer Deep-fertilization technologies and equipments. Professor Wang Jinwu R&D team in Northeast Agricultural University have made some progress in the theory and relative equipments of liquid fertilizer Deep-fertilization after years research and exploration, three generations of prototypes have been developed, which meet the fertilization requirements basically. The key part of prototype is hole-pricking mechanism, whose work performance can influent fertilization quality and efficiency directly. The hole-pricking mechanism has the problem of the limit hole-pricking number in unit time and lower work efficiency. The impact force of spray fertilizer needle applied by soil granule increase with increasing of hole-pricking number, which cause some problems that significant vibration of mechanism, instability of hole-pricking and hole width undesirability.Regarding the issue above, the Bezier pitch curve transmission theory has been studied in-depth in this study on the basis of liquid fertilizer Deep-fertilization relative agronomic requirements, a new type of planetary gear train hole-pricking mechanism with Bezier pitch curve gears was designed. Mechanism of which has been discussed by using theoretical analysis, computer interactive optimization simulation and High-speed Camera technology methods, etc. During research the kinematics and dynamics characteristics has been studied, the influence factors of workability and stability of mechanism, the results will provide important foundation to theory and design of Deepfertilization liquid fertilizer applicator and its key parts. The research contents in this article mainly include the following aspects.(1)The design of planetary gear train hole-pricking mechanism with Bezier pitch curve gearsIn order to avoid vibration effectively of liquid fertilizer applicator during high-speed operation and acquire ideal hole width and hole distance, combined with work and features of multiple mechanisms and introduced planetary gear train with Bezier pitch curve gears on the basis of in-depth discussion liquid fertilizer Deep-fertilization theory, a new type of hole-pricking mechanism has been designed after analysis of its transmission ratio, pressure angle and pitch curve convex check.(2)Kinematics and dynamics modeling and simulation analysis of planetary gear train holepricking mechanism with Bezier pitch curve gearsIn order to check whether the mechanism design is reasonable, components in the process of running with and without interference and whether the running track meet the fertilization requirements, kinematics and dynamics models have been built, simulation analysis of mechanism by using software. Concrete research contents such as, building(angel)displacement,(angel)velocity,(angel)acceleration kinematics model of each gear and spray fertilizer needle. To explore stress changing rules on axes and meshing points of sun gear, middle gear, planet gear and planet carrier mathematical model have been deduced. The kinamatics simulation analysis have been completed by using Pro/E three dimensional software, in which spray fertilizer needle’s kinematical characteristic curves including location, velocity and acceleration have been acquired. The results verified the accuracy of the theoretical models and provided the basis for dyanmics and kinematics optimization programming.(3)Writing dynamics software of hole-pricking mechanism and solving dynamic model in theoryTo test and verify the accuracy of theoretical model, the dynamics models have been solved in theory by using the method of solving dynamic equations of sequence. Dynamics software of hole-pricking mechanism has been explored by using Visual Basic 6.0 language, in which all the gears hearts and stress of the meshing points and the chain stress changing rule with the rotation angel of planet carrier, which can provide data for the analysis of dynamic characteristics of the whole machine.(4)3D entity modeling and virtual prototype assembly of planetary gear train hole-pricking mechanism with Bezier pitch curve gearsTo complete the parts structure design of mechanism, 3D entity model and virtual prototype assembly of planetary gear train hole-pricking mechanism with Bezier pitch curve gears have been built by using Pro/E software, the institutions run situation, interference and motion have been checked, which can lay a foundation for parts processing and manufacturing.(5)Work performance test research of planetary gear train hole-pricking mechanism with Bezier pitch curve gearsTo check work performance and stability of hole-pricking mechanism, high-speed camera bench test and hole-pricking performance test have been tested in the soil bin, spray fertilizer needle’s running track and the grave and unearthed gesture have been interpreted and kinematics models and theoretical analysis’ validity of mechanism by high-speed camera bench test. Interaction between forward and rotational speed and hole width and distance by multiple hole-pricking performance test. The optimum factors have been acquired by using multipurpose optimal method taking fertilizer requirements as constraint conditions, performance indicators have been tested under the optimum factors.(6)The dynamic test study of planetary gear train hole-pricking mechanism with Bezier pitch curve gearsTo test and verify whether the conclusion of dynamics model and theory solution are accurate, study the rules and reasons of machinery vibration, dynamic test bench was designed and built by using srain sensor electrical measuring principle, in which the kinematic parameters have been acquired. The changing rules were acquired through test including stress on axes angel meshing points of gears, bearing bracket and chain changing with planet carrier rotation angel, the results have proved that accuracy of solving theory and feasibility of test method by compared to theoretical analysis. The soil counter-force’s changing rule with certain rotation speed and forward speed applied by spray fertilizer needle, which can provide the theoretical basis for the study of the whole machine vibration.