气力式油菜、小麦兼用精量排种器设计及排种分析

为提高播种机具的利用率，实现油菜和小麦的兼用播种，本文针对油菜和小麦的机械物理特性，设计了一种气力式油菜小麦兼用型精量排种器，确定了排种滚轮、护种板、气室等关键部件的主要结构参数；分析了充种、清种和卸种过程中的种子运移规律，得出油菜、小麦的充种极限速度分别为0.18m/s、0.13 m/s，油菜、小麦的护种板护种角分别为31.5?~43.2?、36.18?~41.40?， 油菜、小麦的气室气压分别为＞342Pa、＞458Pa。台架试验表明所设计的排种器能满足农艺上油菜和小麦播种的要求。 

Design of Pneumatic Precision Seed-metering Device and Analysis of Seeding Process for Rape and wheat

In order to improve the utilization of the planter to sow rape and wheat, based on the physical and mechanical properties of rape and wheat, a rape/wheat precision seed-metering device was designed and the main structural parameters of the seeding wheel, seed protection sheet, air chamber and other key components were determined. The dynamic process of seed filling, seed cleaning and seed unloading was analyzed, and the results showed that the limit seed-filling velocity was less than 0.18 m/s and 0.13 m/s ,the seed protecting angles were 0.175 - 0.24 and 0.201 -0.230 , and the air pressure was more than 342Pa and 458Pa for rape and wheat respectively. The bench test results of the precision seed-metering device indicated that the rape/wheat precision seed-metering device could satisfy the agronomic requirements for seeding of rape and wheat.