基于射流冲击的穴盘立式取苗器高效无损取苗机理的研究

The research object of this project is tomato plug matrix seedlings.According to the complex structure of the pick-up device of the automatic transplanting machine,and the problem of injured seedling and leave out seedling when the machine is operated.Put forward a design scheme of aperture disk vertical air blowing pick-up device based on mechanical vibrations break and the the idea of gas jet impact row matrix seedling nondestructive pushout. Starting with the statistical analysis of the internal relations between mechanical propertie of plug matrix seedling and main influence factors.Experimental exploration the working condition of the root of plug matrix seedling separated with the inner wall of plug based on the mechanical vibrations. Analysis to build a movement trajectory equation and the kinetic model of matrix seedlings under the influence of instantaneous jet impingement. Figuring out the major factor to impact matrix seedlings nondestructive sliding and abscission and its intrinsic relationship, solving the nozzle exit pneumatic parameters physical quantities when matrix seedling zero speed off.Exploring the impact of the structure working parameters of the jet injection system to various performance indicators of nondestructive pick-up seedlings.Determining the primary influencing factors and the optimal level.Using surface response method to optimized the structure parameters that affect performances. Developing the pick-up device which can match mainstream transplanting machine with simple structure, less energy consumption, high efficiency and low damage. The implementation of the project has great significance to the research of nondestructive pick-up seedling device , theory and the development of efficient automatic transplanting operating machinery.

项目以番茄穴盘基质苗为研究对象，针对国内外自动移栽机取苗机构结构复杂，取苗过程中伤苗和漏苗问题，提出基于机械振动破结和气体射流冲击整排基质苗无损推出思想的穴盘立式气吹取苗器设计方案，从统计分析穴盘基质苗力学特性值与主要影响因素间的内在关系入手，试验探究基于机械振动的穴盘基质苗根部与穴盘内壁连结力完全破结的工作条件；分析构建基质苗在瞬间射流冲击作用下的运动轨迹方程和动力学模型，明确影响基质苗无损滑动、脱落的主要因素及其内在关系，求解验证基质苗零速脱落的喷嘴出口气动参数物理量，试验探讨该取苗器射流喷射系统的结构工作参数对无损取苗各性能指标的影响规律，确定其主次影响因素及其最优水平组合；采用曲面响应法对影响各性能指标的结构工作参数进行综合优化，研制能与主流移栽机匹配的结构简单、能耗少、效率高、损伤小的取苗器。项目实施对研究无损取苗方法与理论，开发高效自动移栽作业机械意义重大。

膜上育苗移栽是新疆主要经济作物加工番茄、辣椒等的主栽模式，目前膜上移栽以人工作业为主，半自动移栽机为辅，迫切需要全自动高效膜上移栽机。本项目以番茄穴盘基质苗为研究对象，针对自动移栽机取苗机构取苗过程中伤苗和漏苗问题，开展了基于气体射流冲击推出整排基质苗的穴盘立式气吹取苗器无损取苗机理研究与参数优化，主要研究内容与成果：1）试验测定机械振动、外推和拔取条件下的穴盘基质苗根部与穴盘内壁连结力完全破结的工作条件及参数；2）通过研究射流冲击穴孔时气动喷嘴及穴盘穴孔内部流场特性，确定了有利于穴盘秧苗的平稳和顺利取出的气动喷嘴结构参数和气流初始速度及其变化关系；3）分析构建已破结的基质苗在瞬间射流冲击作用下的运动轨迹方程和动力学方程，明确影响基质苗无损滑动、脱落的主要因素及其内在关系，并通过摄像观察，研究确定投苗初速度与喷嘴压力近似成线性关系，当穴盘倾角a=75°左右时，秧苗投送效果最好；4）设计制作基于自动定盘送盘的整排气动取苗系统，试验可知喷嘴气流初压强为0.2MPa，穴盘倾角90°，喷嘴半径2.5mm时自动取苗系统综合性能指标秧苗的出穴率、基质散落率及秧苗水平横向位移较优；5）提出分膜栽植方式及其工艺，设计研制能与射流冲击自动取苗移栽机匹配的不等径膜上开沟栽植器，试验得出了栽植性能指标最优的因素主次顺序及水平组合，即牵引速度取4.5km/h，盘轮距取130mm，导苗管倾角取77°。项目发表论文6篇，授权发明专利3项，实用新型专利3项，培养研究生4名，培养兵团英才1人，自治区教学名师1人。基本完成任务书各项指标。本项目在气流冲击无损取苗方法及理论、自动定盘送盘机构和膜上开沟定植工艺和装置等方面的取得的主要成果对从事膜上自动移栽机研究的机构和科研人员具有一定参考价值，同时对于边疆高校农机化工程学科建设和人才培养起到了积极作用。