Authors

Abstract

Aiming at the high crushing rate and impurity rate of corn kernel machine harvesting in the Huanghuaihai region, a longitudinal flow conical variable pitch threshing device is designed, which adopts the combined threshing element of "plate teeth + ribs" and the combined threshing concave plate of "leftward round tube type + vertical round tube type". The cob model was established, and the force analysis of the cob threshing process was carried out, and the type of threshing drum and the installation angle of the threshing concave plate round tube were determined as the main influencing factors, and the collision force on the corn cob was taken as the test index. Using EDEM discrete element simulation software, simulation tests were carried out on different types of threshing drums and threshing concave plates with different installation angles of round tubes with corn cobs, and the better threshing method was finally determined: a conical threshing drum at a drum speed of 450 r/min, and a combination of left-facing round-tube-type+vertical round-tube-type threshing concave plates with an installation angle of 10° (front-sparse and back-dense type) were used. Compared with the vertical circular tube type threshing concave plate, the corn cob contact force decreased from 313.5N to 247.3N, which was optimal for threshing in the range allowed by the corn kernel destructive force.

Abstract in Chinese

针对黄淮海地区玉米籽粒机收时破碎率和含杂率高等问题，设计了一种纵轴流锥形变螺距脱粒装置，采用“板齿+纹杆”的组合式脱粒元件以及“左向圆管型+垂直圆管型”的组合式脱粒凹板。建立了果穗模型并对果穗脱粒过程进行受力分析，确定了以脱粒滚筒类型和脱粒凹板圆管安装角度为主要影响因素，以玉米果穗受到的碰撞力为试验指标，利用EDEM离散元仿真软件，分别对不同类型的脱粒滚筒和不同圆管安装角度的脱粒凹板与玉米果穗进行仿真试验，最终确定了较优的脱粒方式：在滚筒转速为450r/min下，采用锥形脱粒滚筒，安装角度为10°的左向圆管型+垂直圆管型组合式脱粒凹板（前疏后密型）。与垂直圆管型脱粒凹板相比，玉米果穗接触力由313.5N下降到247.3N，在玉米籽粒破坏力允许的范围脱粒效果最优。