玉米钵育移栽机钵苗自动切分装置的结构设计与试验研究

发布时间：2018-01-01 07:07

本文关键词：玉米钵育移栽机钵苗自动切分装置的结构设计与试验研究　出处：《黑龙江八一农垦大学》2017年硕士论文　论文类型：学位论文

【摘要】：玉米钵育移栽技术能够增加积温,对于延长玉米生长期、提高单产、改善质量至关重要。纸钵盘透气透水性良好且材料可降解,利用纸钵培育秧苗进行移栽时,苗钵无需分离,更有利于降低秧苗损伤率。分析国内外移栽机发展现状可知,全自动移栽机和半自动移栽机最主要的差别在于取苗和送苗方式的不同以及装置的自动化程度存在差异,全自动移栽机取苗、送苗机构的性能对移栽效果和移栽后秧苗的成活率有十分重要的影响。本文基于导苗筒式移栽机的结构特点,结合纸钵苗育苗农艺和移栽要求,设计一种自动切分苗装置,以达到提高分苗效率、降低秧苗损伤,降低劳动强度的目的。首先,以弯曲、正切、滑切三种破坏方式对纸钵苗力学特性进行研究,分析三种破坏试验力随着位移的变化规律,以此来确定最佳的钵盘破坏方式及所需力的大小。试验结果表明:滑切为最佳的切割方式,所需切割力最小且切割后钵盘完整度最高。其次,提出自动切分苗装置设计目标,建立自动切分苗装置的三维模型,对装置进行干涉性检验及运动学仿真分析,并对关键部件切割刀进行有限元分析。结果表明:机构不存在干涉现象;对刀刃施加50N或100N的力时,变形量分别为0.00266mm和0.00399mm,变形微小,证明自动切分苗装置的设计合理。对PLC、步进电机、气缸和传感器等进行设计与分析,编写PLC控制程序,由气缸带动切割刀往复直线运动来切割钵苗,由步进电机驱动输送链间歇运送钵苗,以此来实现对自动切分苗装置的协调控制。最后,根据三维设计模型搭建自动切分苗装置试验台,对装置的参数进行试验研究。通过单因素和正交试验设计,来确定影响因素范围、因素对分苗成功率的影响顺序以及优化参数组合,采用SPSS和MATLAB进行数据分析。试验结果表明:刀刃弧度55°,送苗频率90株/min,切割速度0.625m/s是一组较优的机构参数,此时分苗成功率为84.2%,钵苗完整度高,分苗效果良好。综上所述,本文通过对纸钵苗力学特性研究获得滑切所需切割力极值范围为30N-40N,在此基础上设计了由PLC协调控制的自动切分苗装置,并通过试验得出了优化参数组合。本文设计的自动切分苗装置对于提高玉米钵育移栽机的自动化程度,减少劳动力的消耗,降低秧苗损伤率有重要意义,为全自动玉米移栽机的发展奠定基础。
[Abstract]:Maize breeding and transplanting technology can increase the temperature, to extend the corn growth period, increase the yield, improve the quality of paper tray is very important. Good permeability and material degradation, cultivating seedling transplanting with paper pot seedling pot, without separation, more conducive to reduce the damage rate of the seedlings. The analysis of the development status at home and abroad transplanting machine the difference, automatic transplanting machine and automatic transplanting machine is the most important difference from the different ways of seedling and the seedling feeding device and the degree of automation, automatic transplanting machine performance of seedling, the seedling feeding mechanism on transplanting effect and after transplanting seedling survival rate has very important effect. The structure features of the guide tube type transplanting machine based on the combination of paper pot seedling transplanting and agronomic requirements, design a kind of automatic segmentation of seedling device, in order to improve the efficiency of seedlings, reduce seedling damage, reduce the labor intensity. First of all, to bend, tangent, sliding cutting three failure modes of the mechanical properties of paper pot seedling, analysis of three kinds of destructive test force changes with displacement, in order to determine the best bowl failure modes and the force required. Test results show that the best way for sliding cutting cutting, required the minimum cutting force and cutting after the bowl to complete the highest degree. Secondly, the automatic segmentation of seedling device design goal, the establishment of 3D model of automatic segmentation of seedling device, analyzed the interference test and kinematics simulation of the device, and the key components of the cutting knife for finite element analysis. The results show that the device has not imposed interference phenomenon; 50N or 100N of the blade force, deformation is 0.00266mm and 0.00399mm respectively, deformation small, proved that the design is reasonable. The automatic segmentation of seedling device of PLC, stepper motor, cylinder and sensor design and analysis, the preparation of PLC The control program, a cylinder drives the cutter to cut the reciprocating motion of seedling, driven by a stepping motor transport chain intermittent transport seedling, in order to realize the coordinated control of automatic segmentation of seedling device. Finally, according to the 3D design model to build automatic segmentation seedling test unit, were studied by single parameters on the device. Factor and orthogonal design to determine the factors influencing scope, order and optimized parameters influencing factors on seedling success rate, using SPSS and MATLAB for data analysis. The experimental results show that the blade curvature of 55 degrees, the seedling feeding frequency of 90 strains of /min, the cutting speed 0.625m/s is a set of parameters of better institutions, this time seedling success rate was 84.2%, seedling seedlings complete degree is high, the effect is good. To sum up, this paper obtained by sliding cutting cutting force required for extreme range of 30N-40N on the mechanical properties of paper pot seedling, on the basis of this. The automatic segmentation of seedling device controlled by PLC, and the parameters are optimized by experiments. The design of the automatic segmentation device to improve the degree of automation of maize seedling breeding transplanter, reduce labor consumption, have important significance to reduce the damage rate of seedling, lay the foundation for the development of automatic corn transplanter.

【学位授予单位】：黑龙江八一农垦大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S223.9

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