新型钵苗移栽机构设计及工作过程分析

发布时间：2018-11-16 07:28

【摘要】：水稻作为我国主要粮食作物之一,其种植面积非常大,大约占粮食总种植面积的四分之一以上,并且产量占粮食总产量的一半左右,是单产和总产量都很高的粮食作物。因此抓好水稻的生产工作,对发展粮食生产的目标具有举足轻重的影响。我国水稻种植基本都是采用人工育秧、插秧、收获的方式,但是这种种植方式劳动强度大,工作效率低,季节性强。因此,加快发展水稻生产机械化,不仅可以有效争抢农时,减少自然灾害对作物带来的损伤,增加作物的种植面积,还能够提高水稻的产量,降低生产成本,减轻劳动人民的负担。同时,推进水稻主要产区生产的机械化以及新的科技技术在水稻生产上的应用、节约劳动成本、提高生产效率和救灾减灾能力,是提高水稻生产能力、加快发展水稻生产的重要技术手段。本文首先分析了钵苗移栽相对毯状苗移栽的优点,以及国内外水稻移栽机构的研究现状和存在的问题。然后在课题组已研制的移栽机构的基础上,分析其优缺点,在取长避短的原则下,针对其存在的问题(不完全齿轮在高速运转时,移栽机构产生的振动较大),提出一种新的移栽机构方案,即以完全齿轮结构代替其不完全齿轮结构完成钵苗移栽机构的工作。通过阅读文献,基于行星齿轮的工作原理,推导出复杂轨迹所需齿轮的设计公式,并以此编写出一款齿轮设计软件。利用齿轮设计软件和三维建模软件Pro/E对新方案中的齿轮进行建模,并进行齿轮啮合试验,确定出齿轮回转中心。对移栽机构秧夹进行改进,增加推秧结构,与新方案移栽机构的其余零件一起进行装配,将装配模型导入到仿真软件RecurDyn中。在RecurDyn中,借助虚拟样机技术,对装配模型添加适当约束,进行仿真分析。对仿真后轨迹进行优化,确定出最优轨迹下齿轮参数。分析该齿轮参数下秧夹速度和齿轮受力情况,发现其满足水稻移栽的农艺要求。最后进行新移栽机构的台架试验,利用3D打印技术,制造出新型钵苗移栽机构的各个零件,根据移栽机构的工作原理,将各个零件进行装配。将试验仪器和材料都准备完成后,借助高速摄像技术,记录下不同转速钵苗移栽机构的工作过程。借助高速摄像软件对移栽轨迹和移栽效果进行分析,发现新方案钵苗移栽机构的静轨迹以及钵苗移栽效果都达到了预期效果,初步证明了新方案设计的可行性。
[Abstract]:Rice, as one of the main grain crops in China, has a very large planting area, accounting for more than 1/4 of the total grain area, and its yield accounts for about half of the total grain yield. It is a grain crop with high yield per unit and high yield. Therefore, the development of rice production has a decisive impact on the goal of grain production. The rice planting in China is based on artificial raising, transplanting and harvesting, but this planting method has the advantages of high labor intensity, low working efficiency and strong seasonality. Therefore, speeding up the development of rice production mechanization can not only reduce the damage caused by natural disasters to crops, but also increase the yield of rice and reduce the production cost. Lighten the burden on the working people. At the same time, to promote the mechanization of production in major rice production areas and the application of new scientific and technological technologies in rice production, to save labor costs, to improve production efficiency and to reduce disaster and reduce disaster is to increase rice production capacity. Accelerating the development of rice production is an important technical means. In this paper, the advantages of potted seedling transplanting relative to carpet seedling transplanting were analyzed, and the research status and existing problems of rice transplanting mechanism at home and abroad were analyzed. Then, on the basis of the transplanting mechanism that has been developed by the research group, the advantages and disadvantages are analyzed. Under the principle of taking the length to avoid the shortage, the existing problems (the vibration of the transplanting mechanism is bigger when the incomplete gear is running at high speed), A new scheme of transplanting mechanism is proposed, in which the complete gear structure is replaced by its incomplete gear structure to complete the transplanting mechanism of seedling. Based on the working principle of planetary gear, the formula of gear design for complex trajectory is deduced, and a gear design software is developed. Gear design software and 3D modeling software Pro/E are used to model the gear in the new scheme, and the gear meshing test is carried out to determine the center of gear rotation. In this paper, the transplanting mechanism was improved, and the structure of seedling pushing was added. The assembly model was imported into the simulation software RecurDyn by assembling with the other parts of the transplanting mechanism of the new scheme. In RecurDyn, with the help of virtual prototyping technology, appropriate constraints are added to the assembly model, and the simulation analysis is carried out. The gear parameters under the optimal trajectory are determined by optimizing the simulation trajectory. It was found that the speed of seedling clamping and the stress of gears under the gear parameters could meet the agronomic requirements of rice transplanting. Finally, the bench test of the new transplanting mechanism was carried out, and each part of the new transplanting mechanism was made by using 3D printing technology. According to the working principle of the transplanting mechanism, each part was assembled. After the test instruments and materials are prepared, the working process of transplanting mechanism of seedling with different rotating speed is recorded by means of high speed camera technology. By analyzing the transplanting track and transplanting effect with the help of high speed camera software, it is found that the static track of the transplanting mechanism of the new scheme and the transplanting effect of the potted seedling have achieved the expected effect, and the feasibility of the new scheme design has been preliminarily proved.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S223.9

【参考文献】