气吸式三七育苗播种精密排种器设计与试验

Design and Test of Precision Seed Metering Device for Panax notoginseng Seedling and Seeding by Air Suction

针对机械式三七育苗播种排种器种子破损率高、需对种子进行预先分级处理等问题,基于负压吸种、毛刷滚清种、正压排种的工作原理设计了一种气吸滚筒式排种器。对充种阶段、清种阶段、携种阶段、投种阶段进行力学分析,研究排种器的主要结构参数,分析影响排种性能的主要因素;结合单因素试验,选取真空度、播种机作业速度、充种室种子质量为试验因素,以合格指数、漏播指数、重播指数为试验指标,进行了三因素五水平二次正交旋转试验,建立了试验指标与试验因素间的回归方程。借助Design-Expert 10.0软件,采用响应曲面法分析得出,影响充种性能的各因素主次顺序为:播种机作业速度、真空度、充种室种子质量。通过参数优化,得到最佳参数组合为:播种机作业速度0.18 m/s、真空度9.6 kPa、充种室种子质量1.2 kg,此时合格指数95.6%,重播指数0.4%,漏播指数4.0%,满足三七播种的农艺要求。

Aiming at the problems such as high seed damage rate and the requirement about seed grading pre-treatment of the mechanical Panax notoginseng seedling seeding device,a kind of air suction roller sowing seed device was designed by using the working principle of negative pressure seed suction,brush rolling and clean seed,and positive pressure throwing seeds.Through the mechanical analysis of the filling stage,the clearing stage,the carrying stage and the sowing stage,the main structural parameters of the seed-arrangement were studied and the main influencing factors of the performance of the seed-arrangement were analyzed.In combination with single factor test results,vacuum degree,drill speed,filling indoor seed quality as test factors,taking the qualified index,the missed seeding index,and seeding replant index as test indexes,three factors five levels quadratic orthogonal rotating test was carried out,to establish the regression equation between the test indexes and test factors,using the Design-Expert 10.0 software,by using the response surface method,all the factors affecting the filling performance of primary and secondary sequences were analyzed as follows:working speed of the seeder,degree of vacuum,and seed quality.Through parameter optimization,it was concluded that the optimal combination of parameters was as follows:the working speed of the seeder was 0.18 m/s,the vacuum degree was 9.6 kPa and the seed quality of the filling chamber was 1.2 kg.At this time,the qualified index was 95.6%,the seeding replant index was 0.4%and the missed seeding index was 4.0%,which can meet the agronomic requirements of Panax notoginseng sowing.