摘要
针对机械式小麦射播排种器作业过程中存在的种子碰撞力较大、破损率高的问题,该研究采用TRIZ(Theory of the Solution of Inventive Problems)理论对小麦机械式射播排种器的关键部件参数进行优化,通过对种子在排种器内部的运动学分析,确定了影响小麦种子与排种器内部碰撞程度的因素为排种器转速、叶片后倾部分曲率半径与叶片安装角度,采用EDEM软件模拟小麦种子在排种器内部的运动情况,以种子破损率、平均排种速度与播种深度变异系数为试验指标,进行台架试验,结果表明,当排种器转速为1000 r/min,叶片后倾部分曲率半径为40 mm,叶片安装角度为15°时,种子破损率为1.1%,平均排种速度为32.5 m/s,播种深度变异系数为8.9%,满足小麦播种作业要求。
This study aims to optimize the key component and blade in a shooting mechanism using the conflict matrix method of TRIZ,in order to improve the emergence rate of seeding,while,to reduce the seed breaking rate,during planting wheat in a mechanical shooting seed-metering device.The structure of blade was designed as a combined blade using the surface and reverse force method in TRIZ,where the backward blade served as an initial part,while the forward blade as an accelerate part.Compared with the previous blades,a combined parameters of optimal structure was achieved to decrease the wheat breaking rate,where the radius of backward and forwardbladeswere4 mm and 800 mm,respectively.The kinematics analysis can be used to clarify the influencing factors related to the internal collision force of wheat seed and shooting performance during the movement of wheat seed inside the shooting device.The specific factors included the rotation speed of seed-metering device,the radius of backward blade,and the install angle of blades.There was also great influence of structural parameters of blades on the movement of wheat seed in the contact process between wheat seed and blades.EDEM software was used to simulate the movement of wheat seed inside the seed-metering device,where the wheat seeds were constructed by a bonding sphere.In a simulation experiment,five blades were designed to explore the shooting performance at different structures and motion parameters.The maximum collision force between wheat seed and blade were determined for the breaking rate of seeds.An orthogonal simulation test was designed to evaluate the experiment indicators,including the average shooting speed,the maximum collision force,and the coefficient of variation for the shooting depth.The test results showed the primary and secondary order of influencing factors for each index.In the maximum collision force,the significance order was the rotation speed of seed-metering device,the radius of backward blade and install angle of blades,whereas,the significance order for the average shooting speed was the rotation speed of seed-metering device,the install angle of blade,and radius of backward blade.Furthermore,the significance order for the coefficient of variation of shooting depth was the rotation speed of seed-metering device,the install angle of blade,and radius of backward blades.The verification bench experiment was performed on the Conservation Tillage Research Center of China Agricultural University,in 2019,where the average shooting speed,seed breaking rate,coefficient of variation of seeding depth were selected as experiment indicators.The power of seed-metering device and forward speed of conveyor belt were provided by an electric motor directly,where the speed was adjusted at five different levels.In the shooting experiment,the average size of wheat seed(Zheng Mai 9023)was 4.1 mm×3.2 mm×2.1 mm,and the average water content was 19.4%.A SF501 high speed camera was used to collect the average shooting speed of wheat seed,with the spotlight and capture frequency was 50 mm and 1000 r/min,respectively.The results show that the maximum collision force,seed breaking rate,average shooting speed,and coefficient of variation of shooting depth were 7.3 N,1.1%,32.5 m/s and 8.9%,respectively,while the rotation speed of seed-metering device,radius of backward blade,and install angle of blade were 1000 r/min,40 mm and 15°,respectively.This findings can provide new promising techniques and approaches for the optimization design of seed-metering device in mechanical shooting of wheat.
作者
王英博
李洪文
何进
王庆杰
卢彩云
刘鹏
杨庆璐
Wang Yingbo;Li Hongwen;He Jin;Wang Qingjie;Lu Caiyun;Liu Peng;Yang Qinglu(College of Engineering,China Agricultural University,Beijing 100083,China;Administration of Agriculture and Rural Affairs,Northern Hebei Province,Cultivated Land Conservation Agricultural Science Observation and Experiment Station,Beijing 100083,China;Beijing Key Laboratory of Design and Optimization in Modern Agricultural Equipment,College of Engineering,China Agricultural University,Beijing 100083,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2020年第21期1-10,共10页
Transactions of the Chinese Society of Agricultural Engineering
基金
公益性行业(农业)科研专项(201503136)
教育部创新团队发展计划项目(IRT13039)。
关键词
机械化
优化
小麦
排种器
射播
TRIZ
EDEM仿真
种子破损率
mechanization
optimization
wheat
shooting seed metering device
TRIZ
EDEM simulation
breaking rate
