双行手扶式大蒜联合收获机设计和试验（英文稿）

为解决大蒜机械化收获时损伤率与损失率较高的问题,结合大蒜物理特性和种植模式,该研究设计了一种双行手扶式大蒜联合收获机,主要由挖掘装置,矫正装置,夹持装置,切割装置,收集装置等组成,可一次完成大蒜的挖掘,姿态矫正,夹持输送,茎根切割,低损收集等作业工序。为提高大蒜收获作业质量,采用Box-Behnken中心组合试验方法,以前进速度、挖掘深度、链条距离为试验因素,以损伤率和损失率为评价指标,进行参数优化试验。建立各影响因素与指标之间的回归数学模型,分析各因素对响应值的交互影响,获得最优参数组合为：前进速度0.51 m/s、挖掘深度97.2 mm、链条距离7.6 mm,对应的损伤率、损失率分别为0.65%、1.28%,对优化结果进行验证试验,试验结果表明在最优参数组合下,损伤率为0.63%、损失率为1.25%,各评价指标与预测值均很接近。研究结果可为大蒜联合收获机进一步完善结构设计和工作参数优化提供参考。

Design and test of double-row walking garlic combine harvester

Abstract: The planting area of garlic in China accounts for more than 90% of the whole area in the world. The major producer of garlic also needs mechanized harvesting in modern agriculture in recent years. Two kinds of harvesting technologies are divided mainly into: the widely-used segmented harvesting for the separation of garlic and soil individually, whereas, the new combined harvesting to concurrently separate the garlic, stem, root, and soil. However, the current garlic combine-harvester in the world can only collect the garlic under the upright position and wide rows, but cannot achieve the harvesting and cutting roots of lodging garlic plants. In this study, a novel garlic combined-harvester was designed to improve the harvesting efficiency, while reducing the labor intensity, according to the current state of garlic planting. Some specific conditions were also considered, including the working process of digging, the posture correction of garlic seedling, clamping, cutting, and low-damage collecting. The parameters of key components were determined using a theoretical and dynamic simulation of the operation process. A Box-Behnken orthogonal test was performed, where the forward speed, digging depth, and clamping distance were taken as the test factors, whereas, the damage rate and loss rate were the evaluation indices. A three-factor three-level Box-Behnken simulation was also carried out. A field test was conducted at a planting cooperative in Mindong, Shandong Province of China in May 2019. The test object was set as a variety of "Jinxiang Red Garlic". The shaft of shovel and gearbox gears were adjusted to change the distance between the clamping chains, thereby obtaining the different forward speeds, digging depths, and chain spacing during the test. The damage and loss rates were recorded for the harvested garlic in the field. Variance and response surface were utilized to determine the effects of forward speed, digging depth, and clamping distance on the evaluation index. A Design Export software was selected to optimize the model. An optimal combination of parameters was achieved as followed: the forward speed of 0.51 m/s, digging depth of 97.2 mm, and clamping distance of 7.6 mm, corresponding to the damage and loss rates of 0.63% and 1.25%, respectively. The parameters were tested in the field to verify the accuracy of the optimized model. The relative errors of all indices in the predicted and experimental data were less than 5%, indicating that the model was reliable and suitable for prediction and further optimization. The main factors affecting the damage and loss rates of garlic were determined for the forward speed, digging depth, and clamping distance. The finding can provide a sound theoretical reference for the design and optimization of garlic combine-harvester in mechanized production of intelligent agriculture.