Authors

Abstract

In order to solve the problem of high broken rate and impurity rate in the direct harvesting of corn kernels in China, a flexible threshing element with variable stiffness consisting of a conical spring and rasp bar was developed on the basis of the existing horizontal axial-flow flow corn threshing cylinder structure to achieve low loss harvesting of corn kernels. Through mechanical analysis of the key components of the threshing element, its structure and operating parameters were determined. Then, orthogonal tests were carried out using the feed amount, threshing clearance and cylinder speed as the test factors, and the broken rate and impurity rate of the corn kernels as the test indicators. The results showed that the feed amount, threshing clearance and cylinder speed had a significant effect on the broken rate and impurity rate of corn kernels; the optimum parameters for the corn variable stiffness flexible threshing device were feed amount 6.1 kg•s−1, threshing clearance 40 mm and cylinder speed 392 r•min−1. The broken rate of corn kernels was 1.67% and impurity rate 1.03%. The test results fully met the requirements of the national standards for corn harvesting operations. This study provides a technical basis for the application of the axial flow corn flexible threshing device in the corn direct harvesting combine.

Abstract in Chinese

为了解决我国玉米籽粒直收过程中籽粒破碎率和含杂率高的问题，在现有横轴流玉米脱粒滚筒结构的基础上，研制了一种锥形弹簧和短纹杆组成的变刚度玉米柔性脱粒元件，实现了玉米籽粒的低损收获。通过对脱粒元件关键部件的力学分析，确定了其结构和工作参数。以玉米果穗喂入量、脱粒间隙和滚筒速度为试验因素，以玉米籽粒的破碎率和含杂率作为试验指标，进行了正交试验。结果表明：果穗喂入量、脱粒间隙和滚筒速度对玉米籽粒破碎率与含杂率均有显著影响；玉米变刚度柔性脱粒装置的最佳参数喂入量6.1kg•s-1，脱粒间隙40mm，滚筒速度392r•min-1。此时，玉米籽粒的破碎率为1.67%，含杂率为1.03%。试验结果完全符合玉米收获作业的国家标准要求。本研究为轴流玉米柔性脱粒装置在玉米籽粒直收联合收获机中的应用提供了技术依据。