蔬菜自动移栽机对置秧盘交替自动取投苗机构研究

Alternate Automatic Seedling Picking and Dropping Mechanism Based on Symmetrically Arranged Seedling Trays for Automatic Vegetable Transplanters

针对现有蔬菜自动移栽机茎秆夹持式和钵体顶出式取苗方式的缺点,基于顶出-夹取结合式取苗方式,设计了一种适用于对称布置可弯曲秧盘的交替式取投苗机构。阐述了该机构工作原理、关键点运动轨迹和结构组成。分析了关键因素对秧苗夹持点运动轨迹的影响方式并优选了取值:驱动曲柄转速10 r/min,取投苗摇杆长度为309 mm,驱动气缸伸出速度25 mm/s, 0.8 s内完成拔苗,伸出时刻为提前0.4 s。该参数组合下秧苗夹持点在拔苗阶段最大横向位移9.6 mm,累计横向位移0 mm,理论提升高度44 mm,满足取投苗作业理论要求。以苗龄45 d的辣椒秧苗为作业对象,进行了栽植频率70~120株/(min·行)的取投苗性能试验,试验结果表明,该交替取投苗机构在栽植频率100株/(min·行)时可实现取苗成功率93%,投苗成功率95%,总体成功率88%,满足取投苗作业要求,验证了该取投苗机构的可行性。

China is the largest vegetable producer and consumer in the world, and seedling transplanting is the main method of vegetable cultivation. To address the shortcomings of the two types of automatic vegetable transplanters, the stalk clamping type and the pot ejection type, which are used to pick up seedlings, an alternating seedling picking and dropping mechanism was designd based on the combined ejecting-clamping picking method for symmetrically arranged bendable seedling trays. The mechanism was driven by the combination of crank rocker and cylinder. After the seedling ejecting device released the seedling from the cavity wall of the seedling tray, the pneumatic seedling clip clamped the seedling from the seedling picking position to the seedling throwing position to complete the seedling picking and throwing operation, and the seedling picking and throwing were carried out alternately on the front and rear sides of the seedling tray, thus enhancing the efficiency. The working principle, key point motion trajectory and structural composition of the mechanism were analyzed. The influence of key factors on the trajectory of seedling clamping point was analyzed and the following values were selected. The drive crank speed was 10 r/min, the length of the seedling throwing rocker was 309 mm, the drive cylinder extension speed was 25 mm/s, the seedling pulling was completed within 0.8 s, and the extension moment was 0.4 s ahead. Under this combination of parameters, the maximum lateral displacement of seedling clamping point in the seedling pulling stage was 9.6 mm, the accumulated lateral displacement was 0 mm, and the theoretical lifting height was 44 mm, which met the theoretical requirements of seedling picking and dropping operation. The performance test of picking and dropping seedlings under the planting frequency of 70~120 seedlings/min in a single row was carried out with 45 d growth time of pepper seedlings as the operation object. The test results showed that the mechanism can achieve 93% success rate of seedling picking, 95% success rate of seedling dropping and 88% overall success rate at planting frequency was 100 plants/min in a single row, which met the requirements of seedling picking and dropping operation. The feasibility of the seedling picking and dropping mechanism was verified.