4DL-5A型蚕豆联合收割机关键部件设计与优化

针对国内蚕豆机械化收获作业中存在的含杂多、损失大、破碎高等难题，该研究对集切割、输送、脱粒、清选、收集于一体的蚕豆联合收割机的关键部件进行设计。首先对4DL-5A型蚕豆联合收割机关键部件进行设计与分析，确定割台装置、脱粒装置、清选装置主要工作参数，然后采用二次正交旋转组合试验方法设计试验并用Design-Expert进行数据处理，以含杂率、损失率、破碎率作为响应指标，重点研究4DL-5A型蚕豆联合收割机收获作业中前进速度、滚筒转速和风机转速对响应指标的影响规律，建立含杂率、损失率和破碎率的回归数学模型，通过响应曲面方法分析各因素交互作用影响，对回归模型进行多目标优化，得出4DL-5A型蚕豆联合收割机作业参数的最优组合为：前进速度0.57 m/s，滚筒转速400.45 r/min，风机转速1 265.16 r/min，此时，含杂率3.23%，损失率3.00%，破碎率2.72%。对优化参数进行田间试验验证，测得含杂率3.49%，损失率2.87%，破碎率2.83%，与优化值相对误差分别为8.05%、4.33%、4.04%，结果较吻合。该研究结果可为蚕豆联合收割机设计、结构改进和作业参数调整提供参考。

Design and optimization of the key components for 4DL-5A faba bean combine harvester

Faba bean is one of the food legumes crops to harvest dry and fresh seeds. The manual bean harvesting has posed a great challenge on the Faba bean production with the largest planting area at present, such as high labor intensity, labor shortage, low harvesting efficiency, and lacking special machines. Current combine harvesters or grain threshers cannot fully meet the requirements for faba bean harvesting and threshing. It is very necessary to deal with the mechanized harvesting of faba bean, such as impurities, large loss, and high rate of crushing. In this study, a 4DL-5A faba bean combine harvester was designed to integrate with the cutting, conveying, threshing, cleaning, and collection. The key components of combine harvester were first analyzed to determine the working parameters of the header, threshing, and cleaning device. Then a quadratic orthogonal rotation combination test was designed to process the data by a design expert, where the impurity, loss, and crushing rate were taken as the response indexes. A field test was carried out in the Nantong test base, Jiangsu Province of China from June 13 to 15, 2020. The weather was sunny and the temperature was 32 ℃. The total area of the test base was 7 hm2. The faba bean variety was taken as “tongcanxian No.6”, where the yield per hectare was 3 000-4 500 kg, the average plant height was 852.3 mm, the average minimum pod height was 60.8 mm, and the average weight of 100 seeds was 262.8 g. An analysis was also made to explore the effects of forwarding speed, drum speed, and fan speed on the response index of the combine harvester. A regression mathematical model was established for the impurity content, loss rate, and crushing rate. The response surface method was then selected to implement the multi-objective optimization of the regression model. The results demonstrated that an optimal combination of operation parameters was achieved as follows: the forward speed 0.57 m/s, drum speed 400.45 r/min, and the fan speed 1 265.16 r/min, where the impurity rate was 3.23%, the loss rate was 3.00%, and the crushing rate was 2.72%. A field experiment then verified that the impurity rate, loss rate, and crushing rate were 3.49%, 2.87%, and 2.83%, respectively. The relative errors with the optimized values were 8.05%, 4.33%, and 4.04%, respectively. The findings can provide a strong reference for the design and optimization of structure and operation parameters in a faba bean combine harvester.