蔬菜移栽机斜插夹钵式取投苗装置研制

Development of the seedling taking and throwing device with oblique insertion and plug clipping for vegetable transplanters

针对目前中国蔬菜穴盘苗全自动移栽作业,取投苗装置复杂、易失败等问题,该文设计了一种斜插夹钵式取投苗装置。通过对取投苗装置原理的分析,运用投影法对装置进行设计,确定了装置各结构参数。为保证装置具有良好的取投苗效果,对苗盘倾斜角度及苗夹入穴参数进行了设计,同时分析其运动过程,对比仿真轨迹曲线和试验实际轨迹曲线,验证了方案的可行性。综合考虑影响取投苗效果的因素,以取投苗成功率作为取投苗效果评价指标,选取弹簧刚度系数、主动杆转速、苗盘倾斜角度为试验因素,进行正交试验。试验结果表明:在给定因素水平下,当弹簧刚度系数为500 N/m,主动杆转速为12 r/min,苗盘倾斜角度为45°时,取投苗效果最佳,此时基质破碎率为3.13%,钵苗脱落率为2.43%,取投苗成功率为94.44%,装置的可靠性较高。研究结果可为全自动化移栽研究提供参考。

At present, the vegetable planted by seedling cultivation and transplantation accounts for more than 60% of the total vegetable planting. It has the advantages of high and stable yield, climate compensation and land use efficiency improvement.However, vegetable production belongs to labor-intensive industry, the increasingly serious problem of difficult employment leads to the fact that the labor cost of vegetable production accounts for more than 50% of the total cost of vegetable production, which has become the main factor restricting its development. Therefore, it is an inevitable trend for the sustainable development of vegetable industry to study the mechanization and automation of vegetable transplantation. Taking and dropping seedlings is a very important link in vegetable transplanting. In view of the problems of automatic transplanting of vegetable seedlings in China, such as the complex and easy to fail of seedling picking and throwing device, a kind of oblique inserting plug seedling taking and throwing device is designed in this paper. The principle of picking and seeding device was analyzed, and then the location of taking point, throwing point and any point in the process of picking seedlings were selected. The projection method was used to design the device, and the structure and working parameters were determined. The length of the frame, driven rod, connecting rod, driving rod and seedling clip were 122, 196, 80, 186 and 227 mm respectively. In order to ensure that the device has a good effect of taking and throwing seedlings, the tilt angle of the seedling tray and the parameters of the seedling clamping into the hole are designed, and the movement process is analyzed.The feasibility of the scheme is verified by comparing the simulation trace curve with the actual test trace curve. According to the mathematical model of the working process of seedling taking and throwing device, kinematics analysis and simulation are carried out, and the position of seeding taking and throwing, speed and acceleration curve of the seedling clamp endpoint are obtained, the design meets the requirements of automatic transplanting. Considering the factors affecting the effect of taking and throwing seedlings, the spring stiffness coefficient, rotational speed of the active rod and the inclination angle of the seedling tray are selected as the experimental factors, and the orthogonal experiment was carried out. The results show that the best effect is obtained when the spring stiffness coefficient is 500 N/m, the speed of the active rod is 12 r/min, and the inclination angle of the seedling tray is 45°. Repeated experiments were conducted with the optimum parameters, the results show that the broken rate of substrates is 3.13%, the expulsion rate of seedlings is 2.43%, the success rate of seedling taking and throwing is 94.44%, the reliability of the device is high. The design provides a reference for the study of full automatic transplanting.