自走轮式双行大白菜联合收获机设计与试验

Design and Experiment of Self-propelled Wheeled Two-row Combine Harvester for Chinese Cabbage

摘要:

针对山东地区现有大白菜机械化收获装备转场效率低、切根一致性差及夹持输送损伤较高等问题,结合当地单垄双行种植模式,本文设计了一种自走轮式双行大白菜联合收获机,可一次性完成行距50~60 cm条件下大白菜切根、夹持输送及集箱作业。为提高机具对田间作业条件和植株形态差异适应性,构建机具-土壤-植株耦合切割数学模型与夹持输送受力模型,结合理论分析、农艺空间约束和田间预试验,确定仿形机构、切根机构和夹持输送机构关键结构参数。在此基础上,设计了切割高度、角度和进给量可机械预调的切根装置,并采用表面包覆高密度CR海绵的柔性夹持输送机构,以提高切根一致性并降低夹持输送损伤;以采收合格率为评价指标,选取机具前进速度、割刀转速、切割角度及夹持输送带转速为影响因素开展多因素响应面试验。试验结果表明,当机具前进速度为0.41 m/s、割刀转速为238.62 r/min、切割角度为12.58°、夹持输送带转速为188.23 r/min时,预测采收合格率为95.95%。参数圆整后开展田间验证试验,当机具前进速度为0.40 m/s、割刀转速为239 r/min、切割角度为13°、夹持输送带转速为188 r/min时,大白菜采收合格率最大值为95.17%,最小值为93.00%,平均值为94.08%,夹持输送损伤率平均值为3.55%。田间验证结果表明,该机切根一致性较好,夹持输送过程稳定,转场机动性能与通过性良好,可满足成熟春白菜品种“小义和秋”及相近种植模式下低损机械化收获要求,研究结果可为相近物性条件下大白菜联合收获装备结构优化及作业参数设置提供参考。

Abstract:

Aiming to address the low transfer efficiency, poor root-cutting consistency, and relatively high clamping-conveying damage of existing mechanized Chinese cabbage harvesting equipment in Shandong Province, a self-propelled wheeled two-row combine harvester for Chinese cabbage was designed according to the local single-ridge double-row planting pattern. The machine can complete root cutting, clamping-conveying, and collection of Chinese cabbage in one pass at row spacing of 50~60 cm. To improve its adaptability to field operating conditions and plant morphological variations, a machine-soil-plant coupled root-cutting mathematical model and a clamping-conveying force model were established. Combined with theoretical analysis, agronomic spatial constraints, and preliminary field tests, the key structural parameters of the profiling mechanism, root-cutting mechanism, and clamping-conveying mechanism were determined. A root-cutting device with mechanically presettable cutting height, cutting angle, and feed displacement was developed, and a flexible clamping-conveying mechanism covered with high-density CR sponge was adopted to improve root-cutting consistency and reduce clamping-conveying damage. Taking the qualified harvesting rate as the evaluation index, a multifactor response surface experiment was conducted with forward speed, cutter rotational speed, cutting angle, and clamping-conveying belt rotational speed as influencing factors. The optimization results showed that the predicted qualified harvesting rate was 95.95% when the forward speed, cutter rotational speed, cutting angle, and clamping-conveying belt rotational speed were 0.41 m/s, 238.62 r/min, 12.58°, and 188.23 r/min, respectively. After rounding the optimized parameters, field verification tests were conducted. When the forward speed, cutter rotational speed, cutting angle, and clamping-conveying belt rotational speed were 0.40 m/s, 239 r/min, 13°, and 188 r/min, respectively, the maximum, minimum, and average qualified harvesting rates were 95.17%, 93.00%, and 94.08%, respectively, and the average clamping-conveying damage rate was 3.55%. The field verification results showed that the machine had good root-cutting consistency, stable clamping-conveying performance, and favorable transfer mobility and trafficability. It can meet the requirements for low-damage mechanized harvesting of the mature spring Chinese cabbage cultivar "Xiaoyi Heqiu" and similar planting patterns, and the results can provide a reference for structural optimization and operating parameter setting of Chinese cabbage combine harvesters under similar physical conditions.