气力杯勺式马铃薯排种器的设计与试验研究

发布时间：2018-05-19 06:48

本文选题：气力杯勺式 + 排种器　；参考：《华中农业大学》2017年硕士论文

【摘要】：马铃薯是我国的四大主要粮食作物之一,具有生长期短、营养丰富、产量高和适应性强等特点。目前,我国马铃薯的种植面积和总产量已位于全球首位,而单产水平却低于世界水平,马铃薯的全程机械化已成我国马铃薯产业发展的瓶颈,高效可靠的马铃薯排种器是全程机械化的迫切需求。马铃薯排种器是播种机械的核心装置,播种质量的优劣直接影响到了马铃薯产量的高低。本文在系统比较和分析国内外马铃薯机械化播种技术的基础上,结合我国马铃薯的种植农艺要求,设计出了一种气力杯勺式马铃薯排种器,该排种器主要由种箱、间歇式喂入机构、限流挡板、输种链条、种子室、气室壳体、输种管、杯勺等部分组成,采用杯勺与气力排种相结合的方式来提高排种性能来降低马铃薯的损伤率。本文主要研究内容包括:(1)马铃薯的物理机械特性马铃薯种薯物理机械特性的研究,为排种器的结构设计提供了依据。测得的中薯3号和华薯1号的长度大都集中45~60mm,宽度大部分集中在40~50mm,厚度则集中在30~45mm;中薯3号大多属于圆形,而华薯1号大多属于圆形和椭圆形;测得的在华薯1号、华薯2号和红岛这三种马铃薯顶部的曲率半径大都集中在20mm左右,腰部的曲率半径大部分集中在30~35mm,底部的曲率半径大都集中在20mm左右。马铃薯的形状尺寸、曲率半径等为气力杯勺式马铃薯排种器关键部件的设计提供了参考依据。碰撞损伤力学特性试验为降低马铃薯的损伤率提供了参考。(2)气力杯勺式马铃薯排种器关键部件的设计与研制结合马铃薯的种植农艺要求,设计出了一种气力杯勺式马铃薯排种器,并对排种器关键部件进行了相关参数的设计与计算。其中动盘和定盘的直径都为185mm,动盘的圆周上均布12个型孔;通过马铃薯的三轴尺寸和曲率半径确定了杯勺的最大直径为50mm,杯勺半球形的半径为30mm;由吸种管和杯勺组成的搅种装置,对种子室里最底层的马铃薯产生扰动,防止了架空现象的产生;通过对排种器工作过程的关键位置进行动力学分析,计算得出了单个杯勺吸孔最小临界真空度的理想值P1临=2.1808KPa,并推导得出了能使排种器顺利工作的实际最小临界真空度P2临,为设计真空度相关的试验提供了参考依据。(3)气力杯勺式马铃薯排种器的性能试验通过单因素试验和析因试验,对自行设计的气力杯勺式马铃薯排种器进行了排种性能的检测。单因素试验结果表明,当输种轴转速为5r/min,气室真空度为14KPa时,合格指数随着排种轴转速的增加呈先上升后下降的趋势,排种轴转速为15r/min时合格指数最高,为46.95%;当排种轴转速为15r/min,气室真空度为14KPa时,合格指数随着输种轴转速的增加总体呈下降的趋势,当输种轴转速为3r/min时,马铃薯的喂入量较合适,合格指数最高,为48.65%;当输种轴转速为5r/min,排种轴转速为15r/min时,合格指数呈随着气室真空度的增加上升的趋势,当气室真空度为14KPa时,合格指数最高,为46.95%。析因试验研究表明,排种轴转速和输种轴转速有显著的交互作用,其中,排种轴转速为10r/min时对试验指标的影响要比其他水平显著,输种轴转速为3r/min时对试验指标的影响要比其他水平显著。
[Abstract]:Potato is one of the four major grain crops in China. It has the characteristics of short growth period, rich nutrition, high yield and strong adaptability. At present, the planting area and total yield of potato in China are in the first place in the world, but the single yield level is lower than the world level, and the whole process of potato has become the bottleneck of the development of the potato industry in China. The potato seed metering device is the urgent demand for the whole process of mechanization. The potato seed metering device is the core device of the sowing machine. The quality of the sowing is directly influenced by the quality of the potato. On the basis of the systematic comparison and analysis of the technology of potato mechanization at home and abroad, this paper combines the cultivation of potato in China. A kind of pneumatic cup spoon potato seed metering device is designed. The seed metering device is mainly composed of seed box, intermittent feeding mechanism, flow limiting baffle, seed chain, seed chamber, gas chamber shell, feeding tube, cup spoon and so on. It uses cup spoon and pneumatic seed metering to improve seed performance in order to reduce the damage rate of potato. The contents include: (1) the physical and mechanical properties of potato and the physical and mechanical properties of potato seed potato, which provides the basis for the structure design of the seed metering device. The length of the No. 3 and Hua tuber No. 1 is mostly concentrated in the 45~60mm, the width is mostly concentrated in the 40~50mm, the thickness is concentrated in the 30~45mm; the middle potato No. 3 is mostly round, but the Hua tuber No. 1 is big. The curvature radius of the top of three kinds of potato is mostly concentrated at about 20mm, the curvature radius of the waist is mostly concentrated at 30~35mm, and the radius of curvature at the bottom is mostly around 20mm. The shape size, curvature radius, etc. of the potato are the potato platoon of the gas cup spoon. The design and development of the key components of the potato spoon type potato seed metering device were designed and developed, and the design and development of the key components of the potato spoon type potato seed metering device, combined with the farming requirements of the potato, designed a type of potato seed metering device with a pneumatic cup spoon, and closed the seed metering device. (2) the design and development of the key parts of the potato spoon type potato seed metering device were designed and developed. The key parts are designed and calculated. The diameter of the disc and the fixed disc is 185mm, and the circle of the disc is distributed 12 holes. The maximum diameter of the cup spoon is 50mm and the hemisphere radius of the cup spoon is 30mm through the three axis size and the curvature radius of the potato; the seed room is made up of the seed suction pipe and the cup spoon. The bottom of the potato produced disturbance to prevent the emergence of the aerial phenomenon. Through the dynamic analysis of the key position of the work process of the seed metering device, the ideal value P1 of the minimum critical vacuum degree of a single cup spoon suction hole was calculated, and the actual minimum critical vacuum degree, P2, which could make the seed metering device work smoothly, was derived. A reference basis was provided for the design of vacuum degree related tests. (3) the performance test of a spoon type potato seed metering device was carried out by single factor test and factorial test. The performance of the self designed gas cup spoon potato seed metering device was tested. The single factor test showed that when the speed of the transmission shaft was 5r/min, the vacuum degree of the gas chamber was the same. When 14KPa, the qualification index rises first and then decreases with the increase of the rotation speed of the seed shafts. The qualified index is the highest when the rotation speed is 15r/min, and it is 46.95%. When the rotation speed is 15r/min and the vacuum degree of the gas chamber is 14KPa, the qualified index is generally decreasing with the increase of the speed of the transmission shaft. When the rotation speed of the transmission shaft is 3r/min, the horse bell The feeding quantity of the sweet potato is more suitable, the qualified index is the highest, which is 48.65%. When the rotation speed is 5r/min and the rotation speed is 15r/min, the qualified index increases with the increase of the vacuum degree of the gas chamber. When the vacuum degree of the air chamber is 14KPa, the qualified index is the highest. It is shown by the study of 46.95%. factorial test that the rotation speed of the seed row shaft and the speed of the transmission shaft are significant. When the rotation speed of the seed metering shaft is 10r/min, the influence of the test index on the test index is more significant than that of the other level. The effect of the rotation speed of 3r/min on the test index is more significant than that of the other levels.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S223.2

【参考文献】