菌草穴盘苗取投苗装置设计与试验分析

Design and experiments analysis of automatic taking and throwing device for“Juncao”plug seedlings

目前菌草穴盘苗移栽过程中缺乏自动取投苗装置,通过分析取投苗装置的工作原理,建立运动学模型并优化结构参数,研发一种六杆式取投苗装置。根据菌草穴盘苗钵体的抗压力学特性、取投苗装置的基本约束与空间约束,优化分析得到各杆件的结构参数,建立虚拟样机得到仿真轨迹和运动学参数。进一步研制样机,结合高速摄像技术获取取投苗装置的实际运动轨迹,对比两种轨迹的一致程度,验证装置设计的合理性。以取投“绿洲一号”菌草穴盘苗为例,将主动杆转速、送苗装置倾斜角以及钵体含水率作为试验因素,取苗成功率、投苗成功率作为响应指标,开展三因素三水平正交试验。试验结果表明,在主动杆转速为30 r/min、钵体含水率为60%、送苗装置倾斜角为50°时,取投苗的效果最优。重复试验表明,在最优因素水平下,取苗成功率与投苗成功率分别为95.31%和93.4%。

Seedling transplanting was considered as ones of key steps during“Juncao”planting.However,there is a lack of automatic taking and throwing devices in the in recent years.Alternatively,developing an automatic taking and throwing device can improve the transplanting efficiency as well as reduce labor intensity.This study aimed to develop a six‑bar device by analyzing the working principle of device,establishing a kinematic model and optimizing structural parameters.According to the anti‑pressure characteristics of the“Juncao”plug seedlings bowl and the basic and spatial constraints of the device,the structural parameters of each rod were optimized and analyzed,and the simulation trajectories and kinematic parameters were obtained by establishing a virtual prototype.Furthermore,a prototype was developed and then actual motion trajectory of the taking and throwing device was obtained via a high‑speed camera.The consistency between the two trajectories was compared to verify the reasonability of the prototype.In order to ensure the availability of the developed device,the operation of taking and throwing was carried out by using“Juncao”(Oasis No.1)plug seedlings.The rotation speed of the active rod,the inclination angle of the seedling delivery device and the moisture content of the bowl were used as experimental factors,and the success rates of taking and throwing were used as response indicators.A three‑factor and three‑level orthogonal experiment was performed.The bench test showed that it achieved the best performance when the driving rod speed,water content of the bowl and inclination angle of the seedling feeding device was 30 r/min,60%and 50°,respectively.Repetitive experiments by using the optimal factor level also reached the success rates of taking and throwing of 95.31%and 93.4%.