【作者】 王建峰；

【导师】 宋玉秋； 黄文忠；

【作者基本信息】 沈阳农业大学 ， 农业硕士（专业学位）， 2019， 硕士

【摘要】 水稻旱直播是一种节本增效的种植模式。由于土壤疏松、覆土较浅,造成旱直播水稻种子出苗率低,影响幼苗生长。镇压是使松土紧实,提高土壤墒情,促进种子发芽保证出苗率的主要措施。因此,本文在镇压强度对水稻生长性状影响的试验研究以及播种镇压装置特点分析的基础上,设计了一种加强苗带镇压的镇压装置,并进行了试验研究。主要研究内容及结论如下:(1)以压强为试验因素,以出苗率、水稻苗高为试验指标,进行了镇压强度对水稻出苗及前期水稻生长性状影响的试验研究,结果表明,镇压压强对旱直播水稻出苗和前期生长有显著影响,镇压强度在50k Pa～90k Pa范围时,旱直播水稻生长较好。(2)在分析国内外常用播种镇压装置基础上,设计了加强苗带镇压的镇压装置。优化了镇压轮外轮廓,采取了弹簧调节和填充调节两种方式进行镇压强度调节。(3)利用Solidworks对整个装置进行了实体建模与优化。利用有限元软件ANSYS对关键零部件进行受力分析,优化了主要零部件结构。(4)利用离散元软件EDEM模拟仿真了4种镇压轮作用下下土壤的运动规律,对土壤的受力情况进行分析。结果表明在相同条件下,不同形状的镇压轮作业下土壤受力不同,土壤的破碎程度也不相同,锯齿形镇压轮的作业效果较好。(5)以速度、配重、含水率为试验因素,以土壤坚实度、土壤容重为试验指标进行单因素试验,得出较优的参数范围。通过三元二次回归正交旋转组合试验,得出影响试验指标的最优参数范围,速度为1.3m/s～1.5m/s、配重为16kg～20kg。更多还原

【Abstract】 Dry land rice direct seeding is a kind of cost-saving and water-saving planting pattern.But the emergence rate is low for the loose and shallow cover of soil,affecting seedling growth.Compaction is an effective way to firm the loose soil,increase soil moisture,and promote seed germination.A strip compaction mechanism was designed based on experimental study on effect of compaction pressure on rice growth and the analysis of characteristics of compactors of sowing machine.Experimental study on the compactors was carried out.The main contents and conclusions are as follows:(1)Experimental study on the effect of pressure on emergence and early rice growth was carried out and the results showed that compaction had significant effect on the indicators,and the optimum range of pressure is between 50 k Pa to 90 k Pa.(2)Strip compaction mechanism was designed based on the analysis of common compactors for seeding machines,the outer contour of the wheel was designed and optimized.Two pressure adjusting methods of spring adjusting and counterweight adjusting were designed.(3)Solid modeling and optimization of the entire device with Solidworks was conducted.Force analysis of key components using finite element software ANSYS was carried out and the main components structure was optimized.(4)The motion and stress of soil under four kinds of compactors was simulated with the discrete element software EDEM.The results showed that compression wheel with sharp ridges had the best performance in crushing soil.(5)Experiment study were carried out with factors of operation speed,counterweight and moisture content and indicators of soil firmness and bulk density.The optimum range of parameters were obtained from single factor test and the optimum combination of factors was revealed as speed of 1.3m/s-1.5m/s and counterweight of 16 kg～20 kg from quadratic orthogonal rotation combination experiment.更多还原