油菜精量直播机凸轮摇杆式播量调节机构设计与试验  

Design and experiment of cam-rocker sowing rate adjusting mechanism for rapeseed precision direct seeding machine

作　　者：舒彩霞[1,2] 付云开 王磊 廖宜涛[1,2] 席日晶 廖庆喜[1,2] Shu Caixia;Fu Yunkai;Wang Lei;Liao Yitao;Xi Rijing;Liao Qingxi(College of Engineering,Huazhong Agricultural University,Wuhan 430070,China;Key Laboratory of Agricultural Equipment in Mid-lower Yangtze Rive,Ministry of Agriculture and Rural Affairs,Wuhan 430070,China)

机构地区：[1]华中农业大学工学院,武汉430070 [2]农业农村部长江中下游农业装备重点实验室,武汉430070

出　　处：《农业工程学报》2020年第10期17-25,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2017YFD0700702);国家油菜产业体系专项(CARS-12);湖北省丘陵山区主要农作物机械化生产关键技术装备研发与集成示范:农业部科研杰出人才及创新团队。

摘　　要：针对不同区域的油菜种植农艺差异、不同播期播量差异及播量范围变化大的生产实际,该文设计了一种输出轴与输入轴转速速比范围为0.1~0.45的凸轮摇杆式油菜精量直播机播量调节装置。解析了调节机构的基本运动原理,分析了凸轮摇杆机构凸轮轮廓曲线及从动件运动规律,所设计凸轮轮廓曲线呈纺锤形,从动件位移曲线为螺旋曲线,从动件速度变化曲线为一峰三柱点曲线,从动件角速度变化曲线为2条不同振幅与频率的正弦曲线合并而成。开展了播量调节装置速比精确性和对排种器排种性能影响试验。试验结果表明,不同输入轴转速下,速比为0.2~0.45时播量调节装置输出轴转速相对误差值对比速比为0.1~0.2时较小,平均误差低于3.8%;不同输入轴转速、种床带前进速度下播量调节装置对排种器排种性能影响较小,播量调节装置可实现油菜不同播量需求。预调播量为5 500和6 720 g/hm2进行田间试验,结果表明,油菜各行1 m内平均苗数为16和20,符合预调播量;各行苗数一致性变异系数为6.48%和8.19%,播量调节装置满足油菜对变量播种的农艺要求。According to the agronomic requirements of rapeseed planting,the amount of rapeseed sowing varies in different regions and different sowing dates.Aiming at such production practice,a cam-rocker sowing rate adjusting mechanism for rapeseed precision direct seeding machine with a speed ratio of 0-0.45 was designed.The Newton-Simpson algorithm was used to draw the mechanism diagram at each moment and the basic motion principle of the adjusting mechanism was analyzed.Based on the principle of graphic method,a kinematics mathematical model of the mechanism was established with closed-loop vector equations,and the equations of speed and acceleration were determined to solve the transcendental equations.Combining with the swing law of the active crank of the linkage mechanism and the variation coefficient of travel speed of the cam,the sine varying putter motion law of push rod and cam profile curves were determined.The cam profile curve of the cam-rocker mechanism and the follower motion law were analyzed,the results showed that the cam profile curve was spindle shape,follower displacement curve was a spiral curve,the follower speed curve was a curve with one peak and three column points,and the angular velocity changing curve of the follower was a combination of two different sine curves with different amplitudes and frequencies.During the entire moving process of the follower,the speed and acceleration of follower were continuous,which avoided rigid impact.The cam had a rapid return characteristic and meet the design requirements.The tests of transmission accuracy of sowing rate adjusting mechanism and influence on seeding performance were carried out on JPZS-12 seed-meter test platform.The test results showed that when the rotation speed of input shaft of sowing rate adjusting mechanism ranged from 20 to 100 r/min,comparing with the ratio ranged from 0.1 to 0.2,the relative errors of the output rotation speed of the sowing rate adjusting mechanism was small at the speed ratio ranged from 0.2 to 0.45,the average erro

关 键 词：农业机械 试验 播量 油菜 调节结构 凸轮连杆机构 

分 类 号：S223.23[农业科学—农业机械化工程]