秸秆深埋还田机覆土装置的参数优化与试验

Optimum Design and Experimental Study of Soil Covering Device of Straw Deep-buried Returning Machine

秸秆深埋还田机在田间作业过程中,覆土镇压的效果是检验机具覆土装置设计合理性的关键。由于东北地区棕壤土玉米种植过程中,连年的化肥施用与拖拉机等机组的田间作业,导致土壤犁底层上移、理化性质变差,影响农作物产量,秸秆的焚烧又会造成严重的污染,因此寻求合理的秸秆利用方式变得十分必要。为了改善机组在工作过程中阻力过大、覆土镇压效果差等问题。设计一种螺旋式覆土装置,探究其在机具覆土作业过程中的优缺点。结合覆土原理,通过对覆土装置运动过程中土壤颗粒的运动过程进行分析,通过理论计算和优化设计,确定了螺旋叶片的主要参数:螺旋轴直径为50mm,长度为1100mm,覆土宽度为1200mm,两螺旋叶片间距为500mm,螺距为250mm,最大螺旋升角为16°,螺旋线的圈数为2圈,两螺旋叶片对称布置。为确定机具的最佳工作参数,进行三因素五水平二次回归正交组合试验,试验选取机具的前进速度、覆土器转速、开沟深度为试验因素,覆土合格率为试验指标。通过对田间试验的数据分析,改进后机组的最佳工作性能参数组合为:机具前进速度2km·h-1、覆土器转速290r·min-1、开沟深度25cm。田间试验表明:覆土合格率为97.1%,满足秸秆深埋还田的技术要求和地方标准,可以为秸秆深埋还田机覆土装置的设计与优化提供理论参考。

In the process of field operation of straw deep-buried returning machine, the effect of soil covering and compaction is the key factor to verify the rationality of the design of soil covering device for straw deep-buried returning machine. In the process of corn planting in brown soil of Northeast China, the successive application of chemical fertilizer and the field operation of tractors and other units resulting in the soil plows are moved up, the physical and chemical properties are deteriorated, and the crop yield is affected, and the burning of straw will cause serious pollution, so it is necessary to find a reasonable way of straw utilization. In order to improve the resistance of the unit during the work process and the poor effect of overburdening, a spiral covering device is designed to explore its advantages and disadvantages in the process of covering soil. Combined with the principle of covering soil, we confirmed the main parameters of helical blade as : the diameter of helical axis was 50 mm, the length was 1100 mm, the width of soil covering was 1200 mm, the distance between two helical blades was 500 mm, and the pitch was 250 mm through the analysis of the movement process of soil particles during the movement of the soil-covering device, theoretical calculation and optimization design. The large helix angle is 16 degrees, the helix number is 2 circles, and the two helical blades are arranged symmetrically. In order to determine the optimum working parameters of the machine, the orthogonal combination test of three factors and five levels of quadratic regression was carried out. The forward speed, the squeezing speed and the ditch depth of the machine were selected as test factors, and the coverage rate of the soil was the test index. Based on the data analysis of field tests, the optimum working performance parameters of the improved unit are: the forward speed of the machine tool is 2 km·h-1, the speed of the soil cover is 290 r·min-1, and the ditching depth is 25 cm.Field experiment shows that the qualified rate of soil covering is 97.1%, which can meet the technical requirements and local standards for straw deep burial. It can provide theoretical reference for the design and optimization of soil covering device of deep straw returning machine.