Abstract: In order to solve the problem of high residue in conventional small-scale combine harvester threshing device, this study choosed  Nong-guang 4LZ-0.8 small combine harvester threshing device to carry out improvement, and adopted the combined way of entire process of air-assisted cleaning and winnower clean up to solve high residual defects caused by original screw feeder and scraper transport. The threshing test bed was designed and tested, taking feed quantity, guide duct inlet wind speed, winnower speed as testing elements, and grain residue in threshing device as performance evaluation index. The single element test for maximum feed rate under different wind speeds was firstly conducted to confirm the scope of test elements, and then to establish the residual mathematical model of threshing device by regression analysis method, and to optimize the best combination of parameters. The results showed that when the feed rate was 0.6 kg/s, wind speed of the duct was 12 m/s, and the speed of winnower was 1 000 r/min, the total residual amount inside the device was 0.18 g.

Key words: rice, breeding, self-purification, threshing device, pneumatic type

摘要： 为解决现有通用小型联合收割机脱粒装置内高残留的问题，选定农广4LZ-0.8小型联合收割机脱粒装置为原型机进行改进设计，为满足育种收获低混种的农艺要求，对脱粒装置底部曲面进行了改进，并采用了全程气流辅助清理和扬谷器清理的组合方式，解决了原有搅龙与刮板输送造成高残留的缺陷。设计了脱粒试验台进行试验，以喂入量、导向风管入口风速、扬谷器转速为试验因素，以脱粒装置内谷粒残留量为性能评价指标，先进行不同风速下最大喂入量的单因素试验，以确定试验因素范围，再运用回归分析方法建立了脱粒装置清残留的数学模型，优化确定了最佳参数组合。试验结果表明：当喂入量为0.6 kg/s;导向风管入口风速为12 m/s；扬谷器转速为1 000 r/min时，装置内整体残留量为0.18 g。

关键词: 水稻, 育种, 自净, 脱粒装置, 气力式