葡萄埋藤压实一体机关键部件设计与试验

Design and Experiment of Key Components of Grapevine-burying and Soil-compacting Machine

摘要:

针对我国北方露地葡萄种植区犁铲式葡萄埋藤机由于碎土效果差导致覆土不严实易透风,进而使葡萄藤冬季受冻的问题,本文设计了一种带有镇压辊的幅宽可调的葡萄埋藤压实一体机,并应用离散元法和田间试验对机具镇压辊进行选型和工作参数优化。利用EDEM建立土块和土壤基底离散元模型,对铁笼镇压辊、尖形橡胶镇压辊和弧形橡胶镇压辊碎土效果进行了仿真试验,最终选择铁笼镇压辊。设计三因素五水平二次回归正交组合试验探究铁笼镇压辊碎土最佳参数组合,根据仿真试验结果对机具作业参数进行优化;以仿真优化的工作参数进行田间试验,验证机具作业性能。仿真结果表明,对土壤粘结键断裂率影响由大到小为：圆管数量、前进速度、镇压力,且圆管数量与前进速度具有显著的交互作用;对土壤压力影响由大到小为：圆管数量、前进速度、镇压力;以土壤粘结键断裂率和土壤压力最大进行多目标参数优化,得到最优参数组合为：前进速度3.53 km/h、镇压力452 N、圆管数量21个。最优参数组合下进行田间试验,可得碎土率为82.3%,镇压辊镇压后比镇压前土壤紧实度提高11.6 kPa。对整机进行埋藤作业,可得覆土厚度为401 mm、覆土宽度为1 120 mm,试验结果满足葡萄埋藤碎土镇压作业要求。

Abstract:

Due to the low temperature and strong wind in Ningxia in winter,in order to prevent the grapevines from being frostbitten and air-dried,it is necessary to prune the vines and remove them from the shelves,and take soil from the rows to bury them for the winter. In response to the problem of grapevines freezing in winter due to poor soil coverage caused by inadequate soil fragmentation in moldboard-type grape burying machines used in open field vineyards in northern China,an adjustable-width vine-burying and soil-compaction machine equipped with a compaction roller was developed. Discrete element method (DEM) simulations were employed to select the appropriate compaction roller type and optimize the machine's operational parameters. A discrete element model of soil clods and soil substrate was established by using EDEM software,and soil fragmentation performance tests were simulated for three types of compaction rollers: iron cage,pointed rubber,and curved rubber rollers. Based on the simulation results,the iron cage roller was selected as the optimal roller type. A three-factor,five-level quadratic regression orthogonal test was designed to explore the best parameter combination for the soil fragmentation process with the iron cage roller. Operational parameters were then optimized according to the simulation results,and field trials were conducted by using these optimized parameters to validate the machine's performance. The simulation results indicated that the main factors influencing soil bond breakage rate in descending order were the number of tubes,forward speed,and compaction force,with a significant interaction effect between the number of rods and forward speed. Similarly,the main factors affecting soil pressure in descending order were the number of rods,forward speed,and compaction force. A multi-objective parameter optimization was performed to maximize both soil bond breakage rate and soil pressure,resulting in an optimal combination of a forward speed of 3.53 km/h,compaction force of 452 N,and 21 cylindrical rods. Field tests under these optimal parameters achieved a soil fragmentation rate of 82.3%,with soil compaction increased by 11.6 kPa after compaction. In grapevine burying operations,the machine achieved a soil cover thickness of 401 mm and a width of 1 120 mm,the results met the relevant standards and fulfilled the requirements for grapevine burial operations.