棉花移栽机关键部件的研究与试验

发布时间：2018-08-27 16:41

【摘要】：棉花钵苗移栽能够延长作物的生育期,使棉花的产量和品质得到提高,与直播相比具有很大的优势,但我国棉花移栽种植机械化程度不高,现有的移栽方式主要依靠人工移栽,使得移栽的经济效益得不到发挥,制约着棉花产业的发展。在了解、分析国内外移栽机的研究现状和我国棉花移栽的农艺要求的基础上,本论文针对现有的半自动移栽机采用人工喂苗劳动强度大,辅助人员多,移栽速度受到限制,机械效益不明显,难以在大田中推广使用等问题,以棉花移栽机关键部件—钵苗移栽总成为研究对象,开展棉花钵苗的力学特性试验研究,钵苗移栽总成的设计、仿真和试验研究,具体的研究内容和结论如下:(1)棉花钵苗的力学特性试验。以鄂抗棉-10和铜杂411两个品种的棉苗茎杆为研究对象,利用TMS-PRO质构仪对棉苗茎杆进行了剪切和弯曲试验,同时对营养钵钵体开展径向和轴向压缩试验,并对钵苗开展不同高度和次数的跌落试验。探索了棉花茎杆在剪切和弯曲过程中力-位移的变化规律和钵体在压缩过程中的力-位移变化规律,分析了加载速度和品种两个因素对剪切强度和弯曲强度的影响。结果表明:棉花幼苗在不同加载速度下的剪切强度和弯曲强度差异明显,不同品种下的棉花幼苗在相同加载速度下的剪切、弯曲特性差异也明显;在不同加载速度和品种下,加载速度和品种对棉苗的剪切强度和弯曲强度均有显著的影响,其两者交互作用对剪切强度和弯曲强度均无显著影响;通过对钵体压缩得到钵体在径向和轴向压缩方式下的破裂力分别为73.3N~110.5 N和100.3N~192.3 N,钵体的抵抗挤压能力呈现出各向异性;随着跌落高度和次数的增大,钵苗跌落损失率越大。(2)棉花钵苗移栽总成关键部件的设计。完成了对自动分钵装置、投钵装置、栽苗装置、液压传动系统和悬挂装置的结构设计,并对各装置的关键部件进行设计,运用SolidWorks软件对各部件进行建模并对其进行装配,保证各部件间不相互干涉。(3)运用ANSYS对分钵装置中的移盘器进行静力学分析,找到受力薄弱点并进行加强;利用MATLAB/simulink对已设计的液压原理图进行仿真分析,根据仿真结果对液压原理图进行改进减少液压冲击,使其满足工作要求。(4)以钵苗直立度为试验指标,对棉花移栽总成进行室内台架试验,通过对翻转板的宽度和投钵频率进行单因素试验,确定了翻转板最佳宽度和投钵频率,并得到了不同投钵频率下的分钵速度。试验结果表明:翻转板宽度在40mm时获得较好的钵苗直立度,投钵频率在40r/min-80r/min时钵苗直立度较好。(5)运用高速数字化土槽实验室进行移栽总成单因素土槽试验,对移栽总成的移栽效果进行正交试验,并对最优组合进行综合性能的试验。试验结果表明:移栽速度在0.33m/s时钵苗直立度达到最好,开沟器型式Ⅰ时,直立度达到最好,开沟器型式对株距合格率的影响不大,投钵频率在50r/min时,钵苗的直立度最好,株距的合格率最高;通过正交试验,对试验结果进行极差分析,试验因素对钵苗直立度的影响程度由大到小依次为移栽速度、投钵频率、开沟器型式,对株距合格率的影响程度依次是投钵频率、开沟器型式和移栽速度;方差分析中,移栽速率对钵苗直立度的影响显著,各因素对株距合格率的影响均不显著,通过对最优组合进行带钵苗试验,得出钵苗直立度达到67%,株距合格率达到92%。
[Abstract]:Cotton pot transplanting can prolong the growth period of crops, improve the yield and quality of cotton, compared with direct seeding has great advantages, but the mechanization of cotton transplanting in China is not high, the existing transplanting methods mainly rely on manual transplanting, so that the economic benefits of transplanting can not be brought into full play, restricting the development of cotton industry. Based on the analysis of the research status of transplanters at home and abroad and the agronomic requirements of cotton transplanting in China, this paper aims at the problems of the existing semi-automatic transplanters, such as the labor intensity of artificial seedling feeding, the number of assistants, the speed of transplanting is limited, the mechanical benefits are not obvious, and it is difficult to be popularized and used in the field. Part-pot seedling transplanting has always been the object of study. The mechanical properties of pot seedling of cotton have been studied. The design, simulation and experimental study of pot seedling transplanting assembly have been carried out. The specific research contents and conclusions are as follows: (1) Mechanical properties of pot seedling of cotton. The stem of two cotton varieties, Ekang cotton-10 and Tongzayi, have been taken as the object of study, and the quality of TMS-PRO has been used. The shearing and bending tests were carried out on the stem of cotton seedlings, the radial and axial compression tests were carried out on the nutrient bowl, and the drop tests were carried out on the seedlings at different heights and times. The results showed that the shear strength and bending strength of Cotton Seedlings under different loading speeds were significantly different. The shear and bending characteristics of Cotton Seedlings under different loading speeds were also significantly different. Loading speed and variety had significant effect on shear strength and bending strength of cotton seedlings, and their interaction had no significant effect on shear strength and bending strength. The breaking forces of the bowl under radial and axial compression were 73.3N~110.5N and 100.3N~192.3N respectively, and the resistance of the bowl to extrusion was obvious. It shows anisotropy; with the increase of drop height and number of times, the loss rate of potted seedlings will increase. (2) The design of key components of cotton potted seedling transplanting assembly. The software modeled and assembled the components to ensure that there was no interference between them. (3) Static analysis was carried out by using ANSYS to find the weak point of force and strengthen it. The designed hydraulic schematic diagram was simulated and analyzed by using MATLAB / simulink, and the hydraulic schematic diagram was advanced according to the simulation results. (4) The cotton transplanting assemblies were tested on a laboratory bench, and the optimum width and frequency of the turning plate were determined by single factor test with the vertical degree of the bowl seedlings as the test index. The results showed that the potted seedlings had better erectness when the width of the turning plate was 40 mm, and the potted seedlings had better erectness when the potted frequency was 40 R / min - 80 R / min. (5) The single factor experiment of transplanting assembly was carried out in a high-speed digitized soil tank laboratory, and the orthogonal experiment was carried out on the transplanting effect of the transplanting assembly, and the comprehensive performance test was carried out on the optimal combination. The results showed that: when the transplanting speed was 0.33m/s, the potted seedlings had the best upright degree, when the ditch opener type I, the upright degree reached the best, the ditch opener type had little effect on the qualified rate of plant spacing, when the potted seedlings were thrown at 50r/min, the potted seedlings had the best upright degree and the qualified rate of plant spacing was the highest. The influence degree of experimental factors on the vertical degree of potted seedlings was transplanting speed, bowl frequency and ditcher type in turn, and the influence degree on the qualified rate of spacing was bowl frequency, ditcher type and transplanting speed in turn. In variance analysis, transplanting rate had a significant effect on the vertical degree of potted seedlings, and all factors had no effect on the qualified rate of spacing. Significantly, through the best combination of potted seedlings test, the potted seedlings upright degree reached 67%, the qualified rate of plant spacing reached 92%.
【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】：S223.9

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