油菜精量联合直播机凸垄厢面构建装置设计与试验

Design and Experiment of Convex Ridge Surface Shaping Device for Rapeseed Direct Seeding

摘要:

针对现有稻油轮作区油菜精量联合直播种床整理采用旋耕拖板平整厢面、牵引式开畦沟犁组开设畦沟，易出现厢面不平、沟形不稳等问题，提出了旋耕起垄埋茬、封闭型开畦沟、主动式旋压整形、仿形开种沟油菜精量联合直播凸垄种床构建工艺，设计了一种油菜精量联合直播机凸垄厢面构建装置，由开畦沟犁、旋耕起垄刀组配合变轴颈整形辊与仿形机构组成，实现畦沟与厢面旋压整形，构建凸状垄面，并通过与整形辊一体式开种沟圆环进行种沟开设，实现油菜直播播深仿形控制。依据油菜种植畦沟开设要求，设计了由不同犁体曲面构成的组合式封闭型开畦沟犁组，结合提出的垄面构建工艺以及土壤运移规律，进行了变轴颈整形辊结构设计、力学分析和镇压力控制机构设计；通过离散元仿真开展了正交试验，进行了响应曲面分析，以厢面倾角α稳定和沟墙倾角β最大为目标，优化得到较优工作参数为：装置前进速度3.8km/h、旋耕刀转速280r/min、整形辊转速147r/min。田间试验结果表明，装置作业后凸垄厢面轮廓及畦沟沟沟形稳定，仿形部件镇压力控制效果较好，厢面倾角为2.94°，沟墙倾角为49.09°，倾角稳定性系数均大于90%，厢面平整度为12.31mm，土壤坚实度稳定性系数为91.77%，沟深及沟宽稳定性系数均大于90%，条形种沟明显，出苗效果良好；通过跟踪油菜生育周期内畦沟沟形演变情况，发现经过整个冬春油菜生育期，平均畦沟深度减小31.68%，平均上沟宽度增大21.65%，未出现沟墙坍塌现象；装置畦沟开设质量、厢面整形质量、镇压力控制效果和播深控制效果均满足油菜种植要求。

Abstract:

In response to the challenges encountered in the existing rice-rapeseed rotation area during the precision combined direct seeding bed preparation for rapeseed, which involves using rotary tillage drag plates to level the bed surface and a traction-type furrow opener plow to create furrows, issues such as uneven bed surface and unstable furrow patterns are prone to occur. To address these concerns, a construction process for a precision combined direct seeding bed with convex ridge surface for rapeseed was proposed. It involved rotary tillage for ridge formation and residue burial, enclosed furrow opening, active rotary compaction and shaping, and controlled furrow opening for precision seeding. To achieve this, a specialized device was designed, comprising a furrow opening plow, a rotary tillage and ridging knife assembly, a shaping mechanism, and a variable neck shaping roller. This integrated system enabled the formation and compaction of ridges and furrows, leading to convex-shaped planting beds. Furthermore, the system incorporated a circular furrow opener to create furrows while simultaneously ensuring controlled seeding depth.Following the requirements for furrow opening in rapeseed cultivation, a combination of furrow-opening plow units with distinct curved surfaces was designed. Taking into account the proposed bed construction process and soil movement patterns, the structural design of the variable neck shaping roller, the mechanical analysis, and the pressure control mechanism were performed. Orthogonal experiments were conducted through EDEM simulation, and response surface analysis was performed. The stable box surface angle α and the maximum furrow wall angle β were set as objectives. The optimal working parameters obtained were as follows: device forward speed was 3.8km/h, rotary tillage blade speed was 280r/min, and shaping roller speed was 147r/min. Field test results indicated that the device achieved stable ridge surface profiles and furrow shapes post-operation. The profiling component demonstrated effective pressure control, achieving a ridge surface inclination angle of 2.94° and a furrow wall inclination angle of 49.09°, with inclination stability coefficients exceeding 90%. The ridge surface evenness was 12.31mm, and the soil firmness stability coefficient was 91.77%. Both furrow depth and width stability coefficent exceeded 90%, with clear furrowed seed grooves and satisfactory seedling emergence.Tracking the furrow shape evolution throughout the rapeseed growth cycle revealed that during the winter and spring growth periods, the average furrow depth was decreased by 31.68%, and the average furrow width was increased by 21.65%, with no furrow wall collapse observed. The device’s quality of furrow formation, ridge surface shaping, pressure control, and planting depth control all met the requirements for rapeseed cultivation. The research result can provide valuable reference for the improvement and design enhancement of precision combined direct-seeding machines for rapeseed cultivation.