前后分置圆盘式覆土器的试验研究与仿真分析

发布时间：2018-06-04 19:47

本文选题：精密播种 + 前后分置　；参考：《吉林农业大学》2017年硕士论文

【摘要】：随着我国玉米种植技术和精密播种技术的迅速发展,精密播种机械各工作部件的设计和完善变得尤为重要,新装置、新原理在精密播种机具上的应用和开发也更加迫切。精密播种不仅需要排种器投种精确,在株距、行距、单粒播种方面达到精度要求,同时也要求影响种子分布均匀性以及播种深度一致性的覆土器在结构和性能方面满足要求,有利于种子初期的生长发育和后期的水肥汲取、光和作用等,有利于提高作物产量。基于降低覆土过程中土壤对种子的冲击、减小种子的位移、提高种子分布均匀性和覆土厚度一致性的目的,本文设计了一种前后分置圆盘式新型覆土器,使两组圆盘的覆土量等同于传统一组圆盘的覆土量,避免了一次性覆土量过大使种子产生较大位移的弊端,前端的一组小覆土盘先用少量潮湿土壤覆盖于种子表面,完成第一次覆土,再由后端的大覆土盘完成第二次覆土。由于第一次覆土时覆土量小,对种子冲击小,因而种子位移变化量小,而二次覆土过程中只会对一次覆土完成后形成的土壤表面产生冲击,种子不会发生位移,既满足了覆土厚度要求又改善了覆土质量,为种子萌发提了供良好的土壤环境,更适于精密播种的技术要求。本文运用SolidWorks软件建立了前后分置圆盘式覆土器的三维模型,利用有机玻璃等材料完成了覆土器实体的加工制作。按照均匀试验设计方法进行了前后分置圆盘式覆土器的土槽试验,通过对土槽试验的数据分析得出前后分置圆盘式覆土器的最优结构参数以及覆土厚度和种子位移的回归方程Y1和Y2:Y_1=58.5+0.4A+1.28B+0.7C+0.15D+0.15AB-0.44AC-0.25AD-0.42BC+0.18BD-0.21CD+0.3A~2-0.34B~2-0.009625C~2-0.6D~2Y_2=4.39+1.03A+0.25B+0.14C+0.14AB-0.22AC+0.0075BC-0.095A~2+0.047B~2+0.075C~2回归方程Y1中A、B、C、D分别代表小圆盘直径、大圆盘直径、覆土偏距、圆盘张角,回归方程Y2中A、B、C分别代表小圆盘直径、大圆盘直径、圆盘张角。本文运用EDEM离散元软件对最优覆土器的覆土过程进行仿真分析,仿真分析结果与土槽试验结果基本一致,验证了利用离散元软件进行覆土过程仿真分析的可行性,为精密播种机研究与设计提供了新方法,进一步丰富了精密播种技术与理论。
[Abstract]:With the rapid development of maize planting technology and precision seeding technology in China, the design and improvement of the working parts of precision seeding machinery becomes particularly important, and the application and development of new equipment and new principles in precision planter are more urgent. Precision seeding requires not only the precision of seeding device, but also the structure and performance of mulch, which affects the uniformity of seed distribution and sowing depth, and meets the requirements of precision in plant spacing, row spacing and single seeding. It is beneficial to the initial growth and development of seed, the absorption of water and fertilizer, light and effect, and the increase of crop yield. In order to reduce the impact of soil on seeds, reduce the displacement of seeds, and improve the uniformity of seed distribution and the consistency of soil thickness, a new type of soil cladding device was designed in this paper. The amount of soil covered by two groups of disks is equal to that of a traditional group of disks, which avoids the drawback that the amount of soil covering over the ambassadorial seed produces a large displacement at one time, and a group of small soil covers in the front end cover the surface of the seed with a small amount of wet soil first. Complete the first soil cover, and then the back end of the large earth cover plate to complete the second soil cover. Because of the small amount of soil covering and the small impact on the seed during the first time, the change of the displacement of the seed is small. However, in the process of the second soil covering, the surface of the soil formed after the completion of the first cover will only be impacted, and the seed will not shift. It not only meets the requirements of covering soil thickness but also improves the quality of soil covering. It provides a good soil environment for seed germination and is more suitable for precision seeding. In this paper, SolidWorks software is used to set up the three-dimensional model of the front and rear dissected disc cladding, and the processing and manufacture of the earth-cladding entity is accomplished by using organic glass and other materials. According to the uniform test design method, the soil trough test of the front and rear dissected disc cladding device was carried out. The optimum structural parameters and the regression equations Y1 and Y2:Y_1=58.5 0.4A 1.28B 0.7C 0.15D 0.15AB-0.44AC-0.25AD-0.42BC 0.18BD-0.21CD 0.3A~2-0.34B~2-0.009625C~2-0.6D~2Y_2=4.39 1.03A 0.25B 0.14C 0.14AB-0.22AC 0.0075BC-0.095A~2 0.047B~2 0.075C~2 regression equation Y1 and Y2:Y_1=58.5 0.4A 1.28B 0.7C 0.15D 0.15AB-0.44AC-0.25AD-0.42BC 0.18BD-0.21CD 0.3A~2-0.34B~2-0.009625C~2-0.6D~2Y_2=4.39 1.03A 0.25B 0.14C regression equation Y1 are obtained by analyzing the data of soil trough test. The diameter of the small disk is represented by the Agna Bu Con D, which is the diameter of the small disc. Large disc diameter, overlying offset, disc angle, and A _ (B) C in regression equation Y _ 2 represent small disc diameter, large disc diameter and disc angle respectively. In this paper, the EDEM discrete element software is used to simulate and analyze the soil overburden process of the optimal overburden. The simulation results are basically consistent with the results of the soil trough test, which verifies the feasibility of the simulation analysis of the soil covering process using the discrete element software. It provides a new method for the research and design of precision planter and further enriches the technology and theory of precision seeding.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S223.2

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