【作者】 杜辉；

【导师】 李汝莘；

【作者基本信息】 山东农业大学 ， 农业机械化工程， 2003， 硕士

【摘要】 小麦精量播种技术具有省种高产的优点，受到了广大农民的欢迎。但是，目前国内使用的小麦精播机绝大多数是机械式，对种子的尺寸要求严格，而且容易造成一定的种子破碎率。气力式精量播种机，由于不伤种子、对种子外形尺寸要求不严、通用性好，是今后精播机发展的主要方向。但是由于气力式排种器的制造精度和成本较高、播种机的总体结构较为复杂，所以在研制和开发上还有许多工作要做。山东省小麦工程技术研究中心的“小型气吸式小麦精量播种机的研制”课题组，经过前阶段的研究，制造出了精量排种器样品，并初步地研制出第一代样机。但是，前阶段的研究只是局限于精量排种器，没有对第一代样机进行播种试验，缺乏对精量播种机整机结构和性能的深入研究，而且，初步的试验表明，该机存有链条拥土、整机质量大等缺点，因此，需要做进一步的改进研究，以提高其整机的播种性能。本课题就是针对第一代样机存在的缺点，在保留原来的精量排种器的基础上，重新设计刮种装置，极大的提高其刮种效果；提升排种器的安装高度，避免传动链条拥土；通过减小平行四连杆的尺寸使播种单体结构更加紧凑、整机的质量更轻以及采用“前四后二”的播种单体布置方案，等几个主要方面进一步提高了精播机的整机工作性能，使其具有更好的推广价值。笔者通过查阅众多的文献资料，了解小麦精量播种机的研究现状和发展过程。并在此基础上，通过对国内外典型的气力式精量播种机和机械式精量播种机的结构对比，分析了气力式小麦精量播种机的结构特点和今后的发展趋势，进而提出了本课题的研究思路和研究内容。为了获取第一代样机田间作业的第一手资料，笔者利用冬小麦播种时节对第一代样机进行了田间播种试验。试验表明，第一代样机的排种粒距与设计粒距有较大的偏差，而且有的播种区段重播率比较高。为了进一步验证精量排种器的性能和工作情况，笔者利用播种机试验台做了排种器的台架试验，通过试验发现排种器的组合刮种器工作不可靠，影响了排种质量，为此提出了提高刮种器工作可靠性的改进方案。 <WP=7>此外，针对第一代样机田间试验所出现的链条拥土、整机质量过大、作业时纵向稳定性差等问题，通过提高排种器的安装高度、减小机架型材尺寸、缩短排种器与地轮的距离、采取“前四后二”的单体排列方案等，有效地克服了第一代样机存在的弊端，使新样机的设计更趋合理。在整机构件的联接中运用了可拆卸性设计方法，提高了构件联接的可拆卸性。制造出新样机后，参照GB6973—86《单粒（精量）播种机试验方法》的基本要求进行了动态试验，测定出新样机的排种性能指标：合格指数大于45%，漏播指数小于30%，粒距变异系数小于22%。新刮种器与原来的排种器配合，基本上能满足小麦精量播种的要求。经过对小麦精量播种机的改进设计，新样机的整机结构和播种性能都有了较好的改进。但是，由于时间限制，新样机还存在几个局部问题有待进一步的研究，为此，笔者从排种器的制造材料及制造精度、排种导种管形状等方面为该机的进一步改进提出了积极性建议。更多还原

【Abstract】 In these years, farmers have reaccepted the precise plant technology with seed saving and high production. But, until now, the prevalent wheat seeders equipped with mechanical drills have disadvantages of request rigorous seed’s demission and too much crash. Because of low crashing and high universality, wheat pneumatic will become the main evolutive direction. But, the manufactural precise and the cost of pneumatic drill are very high, so there are many research works in this fields.Through former phase pursuit, the research of monotype wheat pneumatic precision seeder has manufactured precise drill and the first generation wheat precise seeder. But the former research limit to precise drill, there is no having insemination experimentation, so lacking of the research on structure and capability of whole seeder. Elementary experiment indicates that the first generation precise seeder have many extrusive problems: soil jamming in chain、too much whole weight, and so on. So it is necessary to do more improved study work to advance the precise insemination.To resolve these problems of the first generation precise seeder, on the base of reserving former precision seeder, blow setting is redesigned to improve effect , fixing height of drill is heightened to avoid drive-chain jams soil, minishing the dimension of parallel-four- connecting rod to make planting monomer structure more together and the weight of whole machine lighter. Using the "four monomer at front and two at back" mode, which improve the precise insemination and develop better extensive value.By referring many literature information, penman learn that the present research condition and developing process of wheat precision seeder. By contrasting domestic and international typical pneumatic and mechanical precision seeder, penman analyzes many kinds seeder’s structure characteristic and evolutive direction, and brings forward research course and content of the<WP=9>study.To get the first hand information about insemination of the first generation seeder, penman does dynamic insemination experiment on field. The experiment indicates that there is bigger windage between the grain distance of rowing seed and designed grain distance, furthermore reseeding rate of some field is higher. In order to verify performance and work condition of precise drill, penman do also dynamic insemination experiment on drill. The result indicates that the perform of blow component is bad, which affect the drill’s perform seriously, so it is requisite to improve the dependability of blow component.Furthermore, as to the problems, such as soil-jam, too much quality, too bad portrait stability, the altitude of drill is heightened and framework is shortened. At the position of whole seeder, this six monomer is arranged according to the "four monomer at front and two at back". At component link, the design for disassembly is applied. By the above improve design, the structure and capability of new pneumatic precise seeder become more perfection.After making new machine, penman do dynamic experiment according to national standard GB6973—86, mensurate rowing seed capability target: The qualified index of seed space is over 45 percent; the coefficient of variation is less than 22 percent. New blow component concerts former rowing seeder, which satisfies basic demand of wheat precision seed.Owe to improved design of wheat precision seeder, the whole structure and planting seed capability of new machine are increased at some extent. But, because of limited time, there are still some small local problems lying in the new seeder. So, from the material of drill, precise of produce and the form of seed-guide-pipe, some constructive advice has been brought forward.更多还原