自走式棉秆收获打捆机动定刀式粉碎装置设计与试验

Design and Experiment of Moving and Fixed Knife Type Crushing Device for Self-propelled Cotton Stalk Harvesting and Baling Machine

摘要:

针对棉秆收获机粉碎装置粉碎效果差、棉秆损失率高的问题，本文设计了一种自走式棉秆收获打捆机动定刀组合式粉碎装置。通过对旋转刀辊、甩刀以及螺旋输送器等关键部件进行理论分析，确定了相关设计和工作参数；运用EDEM软件进行棉秆粉碎抛送的离散元模拟仿真试验，分析得到刀辊转速较优参考值，然后通过田间试验对装置进行验证。以棉秆粉碎合格率和棉秆损失率为评价指标，以刀辊转速、刀具离地高度、前进速度为试验因素，进行单因素试验确定三因素合理参数范围，再运用Design-Expert 13.0软件进行三因素三水平Box-Benhnken试验，获得较优工作参数：刀辊转速2 100 r/min、刀具离地高度80 mm、前进速度8.5 km/h。在此参数组合下进行3次田间验证试验，棉秆平均粉碎合格率为96.82%、棉秆平均损失率为3.64%，与理论优化值误差均小于5％，结果符合作业标准，可为后续机型开发提供理论参考。

Abstract:

In response to the problems of poor crushing effect and high loss rate of cotton stalks in the mechanical crushing device for harvesting, a combined moving and fixed knife crushing device for a self-propelled cotton stalk harvesting and baling machine was designed. Through theoretical analysis of key components such as the rotating knife roller, the swinging knife, and the screw conveyor auger, relevant design and working parameters were determined; a discrete element simulation experiment for the device's crushing and throwing of cotton stalks was conducted by using the EDEM software, and the optimal reference value for the rotational speed of the knife roller was obtained. Then the device was verified through field trials. The field trials used the cotton stalk crushing qualification rate and the cotton stalk loss rate as evaluation indicators, and the knife roller rotational speed, height of knife above the ground, and forward speed as the three factors of experiment. Firstly, single-factor experiments were conducted to determine the reasonable parameter ranges of the three factors, and then a three-factor three-level Box-Benhnken experiment was carried out by using the Design-Expert 13.0 software; the optimal working parameters were obtained: the knife roller rotational speed was 2,100 r/min, height of knife above the ground was 80 mm, and forward speed was 8.5 km/h. Three field verification experiments were conducted under this parameter combination, and the average cotton stalk crushing qualification rate was 96.82%, and the average cotton stalk loss rate was 3.64%. The results were within 5% of the theoretical optimization values, and the results were in line with the operation standards, providing theoretical references for the subsequent model development.