【摘要】 针对牵引式旱地激光平地机转弯半径大、两轮支撑易出现压实轮辙、小田块精准平地适应性差等问题,设计了一种悬挂式多轮支撑旱地激光平地机,该机通过拖拉机三点悬挂机构浮动功能与多轮支撑相结合,实现激光控制平地作业。建立了平地铲浮动调节数学模型,确定了平地机结构参数与工作参数,分析了支撑轮对土壤的压实,设计了由两组刚性轮组成的支撑轮结构,减小了支撑轮对松软土壤的压实轮辙。田间试验结果表明,悬挂式多轮支撑旱地激光平地机作业性能稳定,田面最大高程差从平整前20. 8 cm降至平整后7. 3 cm,相对高程标准偏差Sd从平整前4. 48 cm下降到平整后1. 72 cm,平整后绝对差值小于3 cm的采样测量点累计百分比91. 94%,显著改善了田面平整情况,满足田块精准平地要求。平地前后网格点土壤紧实度分析结果表明,悬挂式多轮支撑旱地激光平地机的多支撑轮对试验田块0～17. 5 cm深度范围的土壤紧实度具有一定的压实影响,深度达17. 5 cm及以上时,土壤紧实度基本稳定,整田表层土壤压实均匀。松软土壤经过均匀压实后,减小了土壤后期的沉降,保证了田面平整度。通过作图法对比分析了悬挂式平地机与牵引式平地机在田角处不能平整的面积比例,平整100 m×100 m、36. 5 m×36. 5 m、25. 8 m×25. 8 m田块时,牵引式平地机不能平整面积占比分别为0. 78%、5. 8%和19. 4%,而悬挂式平地机不能平整面积占比小,分别为0. 09%、0. 68%和2. 25%,表明悬挂式平地机小田块平地作业更具优势。更多还原

【Abstract】 The laser land leveling of turning radius is large and the two-wheel support is easy to appear rim,which is not suitable for the accurate flat land of the small field. A multi-wheel support laser land leveling hanging on tractor was designed. By analyzing the floating function of the three-point suspension mechanism of the tractor and the multi-wheel support,the working principle of the laser-controlled flat shovel was realized. The mathematical model of the floating lifting shovel was established,and the structural parameters and working parameters of the grader were determined. Based on compaction analysis of the support wheel,the support wheel structure composing of two sets of rigid wheels was designed,which reduced the compaction and rim of the soft surface of the two-wheel support. The field test of the prototype showed that the operation performance of the machine was stable. The maximum elevation difference and standard deviation of the field were reduced from 20. 8 cm and 4. 48 cm to 7. 3 cm and 1. 72 cm,respectively. The cumulative percentage of the sampling points with the absolute difference between the sampling point and the mean was less than 3 cm was 91. 94%,which can significantly improve the smoothing of the field and meet the requirements of accurate flat land in the small field. The soil compaction degree of the grid points before and after the flat ground was compared and analyzed,which indicated that the compaction effect of the multi-wheel support on the test field appeared at 0 ～17. 5 cm. However,when the depth was more than 17. 5 cm,the soil compaction was basically stable,and the surface soil of the whole field was compacted evenly. Moreover,the soft soil was moderately compacted after leveling,which reduced the sedimentation in the later stage of the soil and ensured the smoothness of the field. The percentage of an area that can not be leveled in the field corners of the traction leveler and hanging leveler was analyzed through the mapping method. The result showed that in the 100 m × 100 m,36. 5 m × 36. 5 m and 25. 8 m × 25. 8 m,the proportion of area that can not be leveled with traction leveler was 0. 78%,5. 8% and 19. 4%,respectively,while the hanging leveler was only 0. 09%,0. 68% and 2. 25%,respectively,which showed that the hanging leveler was more suitable for small field flats.更多还原