钵盘苗扇形齿轮式取苗机构的凸轮设计及试验

Design and test of a cam for the plug seedling pick-up mechanism with sector gear

为实现2Y–2型半自动钵盘苗移栽机的自动化取苗,设计了一种由扇形齿轮、沟槽凸轮及伸缩式苗夹组成的钵盘苗自动取苗机构。由于核心部件沟槽凸轮的轮毂形状影响苗夹的运动轨迹,对其主要结构参数包括中心距、摆杆长度和极半径进行了设计计算。对影响机构取苗效果的入苗深度、安装角度、基质含水率和转速进行了正交试验验证。结果表明:当入苗深度为34 mm,安装角度为75°,基质含水率为22%,转速为18 r/min,钵盘苗的基质脱落量、断根总长度及漏苗率最小。

To realize the auto-pick up of plug seedlings by 2Y–2 type semi-auto transplanter, an auto plug seedling pick-up mechanism constituted with sector gear, grooved cam and retractable seedling clip is designed. As the wheel hub-shaped grooved cam influences the motion trajectory, main structural parameters including the law of motion, center-to-center spacing, the length of swing rod and polar radius were designed and calculated. And orthogonal test was applied on the depth reached, the installing angle, the moisture content of the matrix and the rotational speed which influence seedling picking of the mechanism. The results showed that when the depth of the seedlings is 34 mm, the angle is 75°, the moisture content of the matrix is 22% and the rotational speed is 18 r/min, the amount of matrix falling off the plug seedlings, the total length of the broken roots and the seedling leakage rate all reached the minimum.