基于柔性夹持的青菜头收获机设计与试验

Design and Experiment of Tumorous Stem Mustard Harvester Based on Flexible Gripping

为解决西南丘陵山地青菜头机械化收获问题,结合青菜头生物特性和农艺要求,设计了一种具有柔性夹持功能的小型青菜头收获机。阐述了整机结构与工作原理,并对样机关键部件进行了结构设计和理论分析,柔性夹持装置初始间隙为60 mm,最大允许通过青菜头直径为150 mm,分析得到夹持输送带速度为0.37 m/s、所需最大夹持力为38.04 N;对割台架的仿地形能力和结构动力特性进行了分析,可得该结构允许地形起伏度为50 mm,在安装割刀位置振幅最大,前5阶固有频率为115.63~783.60 Hz,远大于发动机和地形产生的激励频率,因此不会发生共振现象。田间试验结果表明,切割及夹持输送机构运行平稳、振动小、切割有力、夹持力度适中;切割成功率为89.5%,青菜头损伤率为10.8%,实际工作效率为0.035 hm^2/h,各项性能指标基本满足设计和农艺技术要求。

In solving the problem on the mechanized harvest of tumorous stem mustard in the southwest hills area and understanding the tumorous stem mustard biological characteristics and agronomic requirements,a small tumorous stem mustard harvester with flexible gripping function was developed.The structure and working principle of the whole machine were described and analyzed,also the parameters of the core parts of the machine were analyzed and determined theoretically,which got the adjustment clearance of the flexible gripping device was between 60 mm and 150 mm,the speed of the gripping conveyor belt was 0.37 m/s,the maximum gripping force required was 38.04 N.The terrain imitation capability and structural dynamic characteristics of the cutting bench were analyzed,the results showed that the allowed topographic relief was 50 mm,the maximum amplitude was at the position of the mounting cutter,and the first fifth natural frequency was 115.63~783.60 Hz which was much higher than the excitation frequency of the engine and the terrain,so there was no resonance effect.The field test results showed that the cutting and gripping conveying mechanism had stable operation which was with small vibration,powerful cutting and moderate gripping force.The success rate of cutting was 89.5%,the damage rate of tumorous stem mustard was 10.8%,and the actual working efficiency was 0.035 hm^2/h,which basically met the requirements of the design and agronomic techniques.The research achievement would provide an important reference for the mechanization of mustard industry.