Abstract: In order to increase the economic return of maize cultivation and expand the promotion degree of maize threshing machinery, this paper aims to improve the threshing and netting rate of maize and reduce the breakage rate of threshing process, and designs an adjustable maize threshing device by studying the structural characteristics of maize threshing device. Through theoretical analysis, the diameter of the threshing device drum was determined to be 600 mm, the length of the grain rod was 1 400 mm, and the length of the adjusting rod was 150 mm. Through mechanical and kinematic analysis of the threshing process, the variable gap of the concave plate screen was derived to be 0-25 mm, and then the threshing gap was derived to be 20-45 mm. According to the design of the threshing drum, the operating parameters were determined, the speed of the threshing drum was 200-300 r/min and the material feed is less than 2.1kg/s. A physical prototype of the adjustable corn threshing device was tested with the adjustment gap, threshing drum speed, and material feed as the test factors, and the threshing rate and breakage rate as the indexes, and the parameters were optimized based on the test results. The results showed that the significance of the factors influencing the corn cleaning rate and kernel breakage rate was as follows: adjustment gap > threshing drum speed > material feed. The results of the validation tests showed that the optimal combination of parameters was 30 mm adjustment gap, 300 r/min threshing drum speed, and 1.5 kg/s material feed rate, and the optimal combination of parameters resulted in 99.07% and 2.23% of corn cleaning rate and kernel breakage rate, respectively, meeting the agronomic requirements of the grain threshing process. This study also provides a reference for the design and optimization of corn threshing equipment.

Key words: maize, threshing, gapadjustable, drum

摘要： 为增加玉米种植经济收益，扩大玉米脱粒机推广度，以提高玉米脱粒脱净率、降低脱粒过程破损率为旨，通过研究玉米脱粒装置的结构特点，优化设计一种可调节式玉米脱粒装置。通过理论分析，确定脱粒装置滚筒直径为600mm，纹杆长度为1400mm，调节杆长度为150mm。通过对脱粒过程进行力学和运动学分析，得出凹板筛可变间隙为0~25mm，进而得出脱粒间隙为20~45mm，根据脱粒滚筒的设计，确定作业参数，脱粒滚筒转速为200~300r/min以及物料进给量小于2.1kg/s。试制一台可调节式玉米脱粒装置物理样机进行性能试验，以调节间隙、脱粒滚筒转速、物料进给量为试验因素，以脱净率和破损率为指标，开展响应面试验，并依据试验结果进行参数优化。结果表明：试验因素对玉米脱净率和籽粒破损率的影响顺序为：调节间隙＞脱粒滚筒转速＞物料进给量。验证试验结果表明最优参数组合：调节间隙为30mm、脱粒滚筒转速为300r/min、物料进给量为1.5kg/s，在最优参数组合下获得玉米脱净率和籽粒破损率分别为99.07%、2.23%，满足谷物脱粒过程农艺要求。该研究也为玉米脱粒装置的设计与优化提供参考。

关键词: 玉米, 脱粒, 调隙式, 滚筒