油菜割晒机双曲柄平面五杆拨禾轮设计与试验  

Design and Test of Double Crank Planar Five-bar Reel in Rape Windrower

作　　者：张敏 金梅 王刚 梁苏宁 吴崇友 ZHANG Min;JIN Mei;WANG Gang;LIANG Suning;WU Chongyou(Nanjing Institute of Agricultural Mechanization,Ministry of Agriculture and Rural Affairs,Nanjing 210014,China)

机构地区：[1]农业农村部南京农业机械化研究所,南京210014

出　　处：《农业机械学报》2022年第1期115-122,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2016YFD0702100);财政部和农业农村部:国家现代农业产业技术体系项目(CARS-12-01A);中央级公益性科研院所基本科研业务费专项(S201921)。

摘　　要：为减少油菜割晒机拨禾轮易缠绕和挂禾等问题,提出了一种双曲柄平面五杆拨禾轮机构,建立了该拨禾轮机构的运动学分析模型。根据双曲柄平面五杆机构存在的约束条件,基于编制的拨禾轮拨指运动分析程序,采用人机交互方式得到了一组满足油菜割晒拨禾要求的拨禾轮机构结构参数组合,实现了拨禾轮拨指低速入禾、加速推送、快速出禾和拨指翻转的动作要求,与偏心式拨禾轮相比,同等回转半径和转速下,增大了拨指动态轨迹“环扣”的高度和宽度。分析了拨禾轮机架初始安装角度以及机具前进速度等参数变化对拨禾轮拨指运动状态、速度、加速度和轨迹的影响,分析得出拨指在一个旋转周期内速度为非匀速变化,拨禾过程拨指速度缓慢变化,加速度无突变,通过拨禾轮转速和机具前进速度合理匹配,可实现零速扶禾,对油菜穗头冲击小,减少缠绕。对比分析得出双曲柄平面五杆机构拨禾轮的拨禾轮线速度比可以按拨禾轮匀速转动并以拨禾轮轴为中心的拨指尖静态轨迹最小内接圆半径为长度的圆周线速度近似计算。开展了双曲柄平面五杆机构拨禾轮和偏心式拨禾轮油菜割晒机对比试验,田间试验表明,相同试验条件下,采用双曲柄平面五杆机构拨禾轮的割晒机铺放角度不大于25°,铺放角度差不大于8°,拨禾轮转速对铺放角度的影响不显著(P=0.165>0.1),拨禾轮类型差异对铺放角度的影响极显著(P=0.002<0.05)。拨禾轮转速对铺放角度差的影响不显著(P=0.750>0.1),拨禾轮类型差异对铺放角度差的影响显著(P=0.015<0.1),双曲柄平面五杆机构拨禾轮试验全程未出现拨禾轮挂禾和缠绕现象。In order to solve the problems such as easy winding and hanging of the reel of rape windrower,a double crank plane five-bar reel mechanism was proposed,and the kinematic analysis model of the reel mechanism was established.According to the constraints of the double crank plane five-bar mechanism,based on the compiled reel finger movement analysis program,a set of structural parameter combinations of the reel mechanism meeting the requirements of rape cutting reel was obtained by human-computer interaction.The movement requirements of the reel s finger for low-speed entry,accelerated push,fast delivery and finger upturned was realized.Compared with the eccentric reel,the dynamic trajectory of the reel was increased at the same turning radius and revolving speed.Height and width of the reel buckle of the reel finger dynamic trajectory were increased.The influence of the initial structure angle of the reel and the advancement speed of the machine on the motion state,speed,acceleration and trajectory of the reel finger was analyzed.The analysis showed that the speed of the reel finger was changed at a non-uniform speed during a rotation period,the reel finger speed was changed slowly during the reeling process,and there was no sudden change in acceleration.By reasonably matching the reel rotation speed and the forward speed of the machine,zero-speed lifting of the grains could be realized,the impact on the rape head was small,and the twine was reduced.The comparative analysis showed that the ratio of the reel linear velocity of the double crank plane five-bar mechanism reel can be obtained by approximately calculating the circumferential linear velocity of the finger tip static trajectory with the reel axis as the center and the minimum inscribed circle radius as the length at a constant rotated speed.A comparative test of double crank plane five-bar mechanism reel and cam-action reel for rape swathing was carried out.Field experiments showed that the laying angle and angle difference was respectively less than or eq

关 键 词：油菜 割晒机 拨禾轮 双曲柄平面五杆机构 

分 类 号：S225.2[农业科学—农业机械化工程]