多臂回转式水稻钵苗高速取射秧装置设计与试验

Design and Experiment of Multi-arm Rotary High-speed Seedling Picking and Shooting Device for Rice Pot Seedlings

摘要:

为提升现有夹苗式水稻钵苗移栽的作业效率与栽植质量,提出了一种多臂回转式高速夹取与对辊加速射秧组合式水稻钵苗移栽方式。将具有低传动比波动特性的二阶卵形齿轮引入行星轮系取秧机构,采用对称布局的四取秧臂结构,以提高机构单周夹取频次。通过建立卵形轮系机构运动学模型,编写用于取秧机构轨迹、姿态优化的辅助设计程序,确定了满足农艺要求的合理参数组合,优选出一种“桃形”取投秧轨迹,并完成轮系设计与仿真验证。为提升高转速工况下的取投秧性能,基于五次多项式运动规律构建了空间摆动凸轮取秧臂机构,实现了低压力角、运动平稳 的推程与回程特性;通过开展单因素试验,系统分析对辊直径、转速、安装位置对加速射秧的影响规律,实现了秧苗的精准加速与定向投射,有效保障钵苗栽植直立度和栽植深度的一致性。以取秧臂转速、对辊转速、射秧角度和土壤含水率为因素,植苗成功率为评价指标进行正交试验,明确了土壤含水率为主要影响因素。单因素试验结果表明:在转速110 r/ min 下,平均取秧成功率达94. 46% ;在射秧速度5 m/ s 条件下,可实现2. 5 ~ 3. 0 cm 理想入土深度;取投秧联合试验表明:平均综合植苗成功率达91. 6% ,平均作业效率达435 株/ min,平均损伤率为2. 1% 。本研究采用取植分离协同作业模式,为水稻钵苗高速高质机械化移栽提供了新的技术路径与实践依据。

Abstract:

Aiming to improve the efficiency and quality of clamp-type rice pot seedling transplanting, a method was introduced. This method combined a multi-arm rotary system for high-speed seedling picking with a pair of counter-rollers for accelerated seedling projection. A second-order oval gear, known for its stable transmission, was used in the planetary gear mechanism. This mechanism featured four symmetrically arranged clamping arms to increase the number of seedlings picked per cycle. A kinematic model and a computer-aided design program were developed to optimize the clamping trajectory and posture. This process led to the identification of an optimal “peach-shaped” trajectory and the completion of the gear system design, which was verified by simulation. To ensure stable performance at high speeds, a spatial swing cam mechanism was designed based on a fifth-order polynomial motion law. This design achieved low pressure angles and ensured smooth movement. Furthermore, single-factor tests were conducted to analyze how roller diameter, speed, and position affect seedling projection. The results enabled precise acceleration and directional projection of seedlings, which was crucial for achieving upright posture and consistent planting depth. An orthogonal experiment identified soil moisture content as the most significant factor affecting the planting success rate. Single-factor tests showed that at a speed of 110 r/ min, the seedling picking success rate averaged 94. 46% . With a projection speed of 5 m/ s, seedlings achieved an ideal planting depth of 2. 5 ~ 3. 0 cm. Combined tests showed that the overall planting success rate was 91. 6% , with an operational efficiency of 435 plants per minute and a damage rate was 2. 1% . In summary, this research adopted a separated seedling-retrieving and seedling-planting collaborative method, offering a technical solution for high-speed, high-quality mechanized rice transplanting.