低位铺放双重缓冲马铃薯收获机设计与试验

针对现有马铃薯收获机分离效果不理想、铺放环节防损减损能力弱、伤薯率和破皮率较高等问题,结合国内北方地区马铃薯种植农艺,采用"振动输送分离+双重缓冲减速+低位铺放减损"的薯-土-杂分离工艺,设计了一种低位铺放双重缓冲减损马铃薯收获机,主要由挖掘装置、仿形松土限深装置、低位铺放输送分离装置、2级振动装置、切土切蔓装置、双重缓冲帘、平土压实装置等部分组成。在阐述总体结构及工作原理基础上,建立薯块运动模型,确定关键部件参数。薯土分离阶段分为振动输送分离段和低位铺放缓冲分离段,以在满足高效分离的同时降低破皮率;优化改进后的仿形松土限深轮,作用在薯垄内部薯块上的挤压力相对减小,即达到薯土松离效果的同时降低伤薯率;平土压实装置,可有效避免薯块被挖掘分离后被再次掩埋,利于捡拾且提高明薯率。台架试验利用碰撞检测技术,分析低位铺放环节的碰撞冲击特征,以揭示缓冲帘减损机理。试验结果表明,在收获速度为0. 88、1. 16 m/s时,纯作业时间生产率分别为0. 41、0. 54 hm~2/h,伤薯率分别为1. 03%和0. 84%,破皮率分别为1. 52%和0. 95%,各项性能指标均满足相关标准的要求。

Design and Experiment of Potato Harvester Using Double Cushions for Low Laying Separation Technology

To reduce the losses of bruising and damage, an appropriate available potato-soil separation technology is essential during the potato harvesting process. Combined with the agronomic techniques of potato cultivation in the north of China, a potato harvester with double cushions at low position laying stage was designed, which was developed with the potato-soil-impurity separation technology of vibration separation, double cushions, and low position laying. The harvester was mainly composed of excavating device, soil loosening and depth limiting device, low position laying and separation device, 2-level vibration device, soil cutting and seedlings cutting device, double cushions, soil compacting and flatting device and other parts. The kinetic models were established at the low position laying stage, and structural parameters of primary components were determined. The potato-soil separation device was divided into vibration separation stages and low position laying separation stage with double cushions, to improve the harvesting efficiency and reduce the harvesting losses. The loosening and depth limiting device was improved to reduce the bruising and damage. Simultaneously, the soil compacting device could effectively prevent potatoes from being buried by soil again after being excavated and separated, which was conducive to picking up and improving the average exposing rate. By impact recording technology, the impact characteristics of potatoes were analyzed at low position laying segment. It was shown that by the test results, the productivity was 0.41hm2/h and 0.54hm2/h, the damage rate was 1.03% and 0.84%, and the bruising rate was 1.52% and 0.95% at harvesting speed of 0.88m/s and 1.16\m/s, respectively. It was noteworthy that the performance indexes met the relevant standards. The research result provided a reference for further study on reducing the potato-soil separation losses to minimum and the optimization and the improvement of separation technology.