秸秆条带捡拾粉碎深埋装置设计与试验

Design and Experiment of Straw PickupCrushed and Deep Buried Device under Strip-tillage

针对东北黑土区保护性耕作秸秆还田条件下,地表秸秆量大导致免耕播种过程易雍堵、播种后地温提升慢等问题,提出了一种秸秆条带捡拾粉碎深埋方式,通过捡拾粉碎机构将地表部分秸秆捡拾粉碎,由罩壳处筛孔完成土秆筛分,集秆螺旋器进行秸秆的定向集运,最后经运秸风机实现秸秆输送深埋。本文对粉碎刀结构、排列方式和转速等关键参数进行确定,对粉碎刀轴的秸秆漏捡区域面积展开分析,通过理论分析和离散元单因素仿真试验明确了集秆螺旋器转速与其所受扭矩和秸秆运动速度之间的关系,初步确定了螺旋器转速为900~1100 r/min,设计了开沟铲的结构参数,并利用离散元全因素仿真试验模拟了作业速度与开沟深度两因素间与表层土壤颗粒运动及开沟铲受力之间的关系,以作业速度、开沟深度和螺旋器转速为因素,秸秆深埋合格率为试验指标进行BoxBehnken试验。田间试验结果表明,当前进速度为3 km/h、开沟深度为290 mm、螺旋器转速为1000 r/min时,其秸秆掩埋合格率为64.2%,其预测值约为67.4%,误差小于5%,满足设计需求。研究成果为东北黑土地保护性耕作推广提供了新的方案和技术支撑。

The large amount of surface straws in the no-tillage planting process results in dragging and piling and the ground temperature rises slowly after planting under the conditions of conservation tillage and straw returning to the field in the black soil area of Northeast China.Aiming at the problems,a method that the straw was crushed and deep buried in the strip was proposes,that was,the surface straw was picked up and crushed by the picking and crushing mechanism,the soil and straw screening was completed by the sieve holes at the cover,the stalk collecting spiral performed the directional collection and transportation of the straw,and finally the straw was transported and buried deeply by the straw conveying fan.The key parameters such as the structure,arrangement and speed of the crushing knife were designed,and the straw leakage area of the crushing knife shaft was analyzed.Through theoretical analysis and discrete element single factor simulation experiments,the relationship between the speed of the stalk screw and the torque and the speed of the stalk movement was clarified,and the speed range of the stalk screw was preliminarily determined to be 900~1100 r/min and the structural parameters of the ditching shovel was designed.And the discrete element full factor simulation test was used to simulate the relationship between the operating speed and ditching depth and the movement of surface soil particles and the force of the ditching shovel,taking the operating speed,ditching depth and stalk collecting spiral speed as factors,the BoxBehnken test was carried out with the qualified rate of straw buried deep as the test index.The field test results showed that when the device’s forward speed was 3 km/h,the trenching depth was 290 mm,and the spiral speed was 1000 r/min,the straw burial pass rate was 64.2%,and its predicted value was about 67.4%under the similar parameters.The error was less than 5%,which met the design requirements of the device.The method results can provide a scheme and technical support for the promotion of conservation tillage in the black soil area of Northeast China.