马铃薯-土壤团聚物高效低损分离机理研究

The contradiction between the separation efficiency of potato-soil and broken skin damage of potato in the process of separating potato-soil has always been the fundamental point of potato harvesting machinery research and needs to be solved effectively. To clarify the mechanism of dynamic breakage and separation of potato-soil aggregates, the development of a new high-productivity and low damage fresh potato-soil separation device has become the key to breaking through the elemental problems of potato harvesting machinery. The parameter optimization of a new device of potato soil separation is an effective way to solve the fundamental problem. According to the joint characteristics of the Hexapod insects, this project intends to develop a third-order six-slinger swing separation screen, which is beneficial to the efficient separation of potato-soil aggregates and the effectual reduction of potato peeling ruin. Based on this, the following contents are studied: (1) Analyze the dynamic fracture and separation characteristics of potato-soil aggregates, clarify the relationship between potato-soil aggregates and separation sieve vibration, and reveal the separation mechanism of potato soil; (2) Combine the performance of the separation sieve with the dynamic fracture separation characteristics of the potato-soil aggregate, and extract the dynamic fracture separation characteristic parameters that can characterize the separation sieve performance; (3) Optimize the design of the potato soil separation device with the best optimization parameters as the optimization target, and obtain the optimal parameter matching of the potato soil separation device. Through the above research, it provides a theoretical basis and technical support for the development of high efficiency and low damage potato-soil separation device.

有效解决薯土分离过程中薯土分离效率和马铃薯破皮损伤之间的矛盾，一直是马铃薯收获机械研究的根本点。研制高生产率、低损伤的新型薯土分离装置，明确马铃薯-土壤团聚物破碎及分离机理，成为突破马铃薯收获机械根本问题的关键，对新型薯土分离装置进行参数优化则是解决根本问题的有效途径。本项目依据六足纲昆虫的关节特点，拟研制利于马铃薯-土壤团聚物高效分离、马铃薯破皮损伤有效降低的三阶六吊杆摆动分离筛，并以此为基础研究以下内容：（1）分析马铃薯-土壤团聚物破碎分离特性，明确马铃薯-土壤团聚物与分离筛耦合振动的作用关系，揭示薯土分离机理；（2）将分离筛性能与马铃薯-土壤团聚物破碎分离特性融合，提取能够表征分离筛性能的团聚物破碎分离特征参数；（3）以表征参数最佳为优化目标，对薯土分离装置进行优化设计，获得薯土分离装置的最佳参数匹配。通过上述研究，为高效率、低损伤薯土分离装置的研制提供理论依据和技术支撑。

为有效解决薯土分离过程中薯土分离效率和马铃薯破皮损伤之间的矛盾，本项目通过室内试验、理论分析、仿真试验及分析、田间试验等形式，开展了相应研究工作。具体研究内容及结果如下：. （1）马铃薯机械损伤特性研究. 通过室内试验探究了马铃薯跌落损伤特性及运动学特性参数随马铃薯损伤影响显著因素的变化规律。对马铃薯表皮的冲击摩擦过程进行理论分析，得到了马铃薯冲击摩擦力数学模型；将室内试验与理论分析相结合获得了不同试验条件下的马铃薯冲击摩擦力；与此同时，获得了马铃薯冲击摩擦加速度的变化规律。. （2）马铃薯-分离筛碰撞模型构建及分析. 结合马铃薯-分离筛碰撞实际，分别建立了马铃薯粘弹塑性模型和分离筛在马铃薯跌落作用下的振动响应模型，并获取了模型的相关参数。. （3）新型摆动分离筛改进设计及加速度测试与分析. 将4SW-170型马铃薯挖掘机中原有的具有二阶筛面的摆动分离筛改进为具有三阶筛面的分离筛，通过测试并分析新型摆动分离筛加速度随分离筛结构及工作参数的变化关系，明确了新型摆动分离筛可满足薯土分离能力逐阶筛面递减、物料输送能力变化不大的设计要求。. （4）马铃薯-土壤团聚物破碎分离机理仿真分析. 将Adams软件与EDEM软件耦合开展仿真试验，对马铃薯-土壤团聚物破碎分离过程和特性进行分析，明确了马铃薯-土壤团聚物破碎分离机理。. （5）马铃薯-土壤团聚物运动学特性分析. 通过对马铃薯-土壤团聚物在各阶筛面上的运动位移和速度进行仿真分析，探究了不同试验条件对团聚物运动特性的影响。. （6）分离筛性能试验及分析. 基于新型摆动分离筛进行单因素试验和分离筛参数优化试验，明确了分离筛结构及工作参数对性能指标的影响规律，获得了可满足性能较优的分离筛参数匹配。.本项目研究成果可为薯土分离装置设计改进提供理论依据及技术支撑。