酿酒葡萄清土起藤机刮板与防寒土相互作用研究

Interaction between the scraper of the wine grape cleaning machine and the anti-cold soil

中国西北酿酒葡萄主产区春季的清土起藤作业机械化刚刚开始,针对目前单刮板清土部件作业整机功耗高,清土效率低以及缺乏与防寒土动态作用的理论研究等问题,该研究提出了刮板式清土机的设计理论及方法,并设计了一种双刮板式清土起藤机。首先,根据中国西北葡萄种植地区清土农艺要求,确定刮板的数量及外形尺寸,然后通过理论分析大刮板的受力,确定影响其工作阻力的主要因素,并通过EDEM离散元仿真,对设计的具有不同曲面形式、切削角及倾斜角的刮板进行土壤离散颗粒群与机械刮板相互作用仿真,分析刮板壅土情况和土壤颗粒群的流动规律,然后设计三因素三水平的正交试验,以壅土量为评价指标获得刮板的最佳工作参数,并进行了台架试验验证。结果表明当刮板曲面为抛物线、切削角为55°、倾斜角为60°时,刮板壅土量最少为43.2 kg,清土效果较佳,与仿真结果一致;加工一台双刮板式物理样机并进行了田间试验,与传统单刮板式清土起藤机进行对比试验,结果表明双刮板式清土起藤机的清土率为75.03%,比传统单刮板清土起藤机提高了27.2个百分点,新研制的刮板相对传统刮板壅土量降低了38.74%。研究结果可为后续研制葡萄藤清土起藤机提供技术参考和理论依据。

Fully automatic soil cleaning and retaining operation in spring have been emerging in the wine grape-producing areas in northwest China.However,some challenges have still remained on the current single scraper soil cleaning components,such as the high power consumption of the whole machine during the operation,and the low soil cleaning efficiency.In this study,a novel double-scraper type soil cleaning machine was developed to explore the dynamic interaction with cold soil during operation in the grape-growing regions of Northwest China.The number and dimensions of the scrapers were also determined.Specifically,the overall dimensions of the machine were 2000 mm×2500 mm×1600 mm(length×width×height),among which the height of the large scraper was 600 mm,the length was 1400 mm,the height of the small scraper was 300 mm,the length was 600 mm,and the single-side soil cleaning depth of the whole machine was 300-500 mm.After that,a theoretical analysis was made to determine the force of the large scraper and its influencing factors of working resistance.An EDEM software was utilized to simulate the interaction between the discrete soil particle groups and the mechanical properties in the different scrapers with various curved surfaces,cutting angles,and inclination angles.As such,a relationship was obtained for the back soil condition of the scraper and the flow law of the soil particle groups.Then,a three-factor and three-level orthogonal test was designed to obtain the best working parameters of the scraper with the amount of back soil as the evaluation index.A single-factor analysis and a bench test were also conducted to verify the simulation.The results showed that the primary and secondary factors were the scraper surface profile,the cutting and inclination angle,in terms of the amount of back soil of the scraper.Furthermore,the best scraping performance was achieved,where the scraper curved surface was in the parabolic profile,the cutting angle was 55°,and the inclination angle was 60°,and the least amount backed soil was 43.2 kg,indicating a better consistence with the simulation.A double-scraper physical prototype was also fabricated.A comparison test was then performed on the traditional single-scraper soil cleaning and retaining machine.The test results showed that the soil removal rate of the double-scraper soil cleaning rattan lifter was 75.03%,which was 27.2 percentage points higher than the traditional single-scraper cleaning machine(47.83%).In response to the requirements of soil cleaning operations in Northwest China,the back soil volume of the newly developed scraper was 91.42 kg,which was 38.74%lower than that of the traditional one in the field.The findings can provide a strong theoretical reference for the subsequent development of a scraper-type soil cleaning machine.