关键词: 玉米, 脱粒, 调隙式, 滚筒

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