甘薯横向水平移栽机刮板式覆土装置设计与试验

Design and Experiment of Scraper Soil Covering Device for Horizontal Transplanter of Sweet Potato

摘要:

甘薯横向水平移栽可提高产量和商品率，但二者被移栽深度严重制约，且机械化移栽对甘薯苗形态要求极高。为此，根据甘薯横向水平移栽农艺要求，针对大田苗移栽的甘薯横向水平移栽机设计了一种刮板式覆土装置以保证移栽深度。首先，对刮板式覆土装置进行结构设计，对其作业时的土壤颗粒运动过程进行理论分析，确定土壤颗粒运动速度和运动方向的主要影响因素为安装倾角α、刮板倾角β、刮板线速度vb，而刮板长度L、宽度W和间距D会影响上土量。然后，进一步理论分析获得刮板式覆土装置安装位置，α、W和D的取值以及vb、β和L的取值范围。最后，基于RecurDyn-EDEM的耦合仿真建立田垄-刮板式覆土装置耦合作用模型，采用Box-Behnken试验设计方法，以vb、β、L为试验因素，以平均覆土厚度为评价指标，分析各试验因素及其交互作用对平均覆土厚度的影响。利用Design-Expert软件得到回归方程的预测模型并进行响应面分析，确定了刮板式覆土装置的最优参数组合：刮板倾角100.35°、刮板线速度1.74m/s、刮板长度150.32mm时性能最优，平均覆土厚度为50mm。田间试验表明最优参数组合下，平均覆土厚度为48mm，移栽深度合格率为96%，覆土厚度标准差为4.6mm。

Abstract:

Horizontal transplanting of sweet potatoes can enhance yield and quality, but both are significantly influenced by the transplanting depth. And mechanized transplanting has extremely high requirements for the shape of sweet potato seedlings. To meet the agronomic requirements of this method, a scraper soil covering device was designed for the horizontal transplanter of sweet potatoes with field seedlings to ensure the transplanting depth. Initially, the structure of the scraper soil covering device was designed, and the theoretical analysis of the movement process of soil particles during its operation was conducted. Factors such as the installation inclination angle α, scraper inclination angle β, scraper linear speed vb, scraper length L, width W, and spacing D were identified as key factors affecting soil loading and particle movement speed and direction. The installation position of the scraper soil covering device, values of α, W, and D, and the acceptable range of vb, β, and L were determined through theoretical analysis. Eventually, a coupling model of the ridge-scraper soil covering device was established by using RecurDyn-EDEM simulation. The Box-Behnken experimental design method was adopted, with vb, β, and L as experimental factors, and the average covering thickness as the evaluation index. The influence of each experimental factor and their interaction on the average covering thickness was analyzed. The prediction model of the regression equation was obtained by using Design-Expert software, and the response surface analysis was carried out. Experimental results determined the optimal parameters for the scraper soil covering device: when the scraper inclination was 100.35°, the scraper linear speed was 1.74m/s, and the scraper length was 150.32mm, the performance was the best, and the average soil covering thickness was 50mm. The field experiment showed that under the optimal parameter combination, the average soil covering thickness was 48mm, the qualified rate of transplanting depth was 96%, and the standard deviation of soil covering thickness was 4.6mm.