2BG-2型玉米垄作免耕播种机播种深度数学模型的仿真与验证

免耕播种机是在地表有残茬和秸秆条件下直接播种，因此保持其破茬质量与播种深度稳定性尤为重要。近年来许多厂家以加大整机重量的方法来提高播深稳定性，这种方法增加了机械对土壤的压实，垄形被压平，沟底坚实度增大，并且机械耗油量增加，影响了作物产量和经济效益。该文以2BG-2型玉米垄作免耕播种机为对象，研究了整机设计与单体受力模型，建立了播种深度变化的数学模型，据此模型进行了计算机模拟，研究了影响播种机播种深度稳定性的相关因素。分析表明：在保持必要的机器质量条件下，应合理布置各部件以加大转动惯量并适当增大压力弹簧的刚度系数以保持播种深度稳定。在不同的机器质量和弹簧刚度系数下，理论摆角和实测摆角随时间的变化趋势基本相同；系统质量为70、110和150 kg时，理论摆角与实测摆角的平均相对误差分别为7.86%、6.98% 和8.07%，理论曲线与实测曲线的决定系数分别为0.9707，0.9692和0.9697；刚度系数为16、20 和25 N/mm时，理论摆角与实测摆角的平均相对误差分别为7.45%、7.91%和8.73%，理论曲线与实测曲线的决定系数分别为0.9767，0.9720和0.9603；建立的播种深度模型可以反映播种作业时摆角的变化趋势。该文可为东北垄作区免耕播种机的设计提供参考。

Simulation and validation of seeding depth mathematical model of 2BG-2 type corn ridge planting no-till planter

Abstract: No-till planter works in the condition that the ground is covered with residual and straw, so it is important to keep its residue cutting quality and to maintain the stability of seeding depth. Based on 2BG-2 type corn ridge planting no-till planter, complete machine design and forces model of the planter unit were studied. Mathematical model of change of the seeding depth was established, and according to this model, computer simulations were conducted to study the related factors affecting seeding depth stability. Theoretical analysis showed that: in order to keep the seeding depth stability, the spring constant should be increased appropriately, and configuration location of the parts, on the basis of ensuring the necessary mass of system, should have reasonable layout to increase the rotary inertia. Field tests showed that: trends of the theoretical angles over time were similar with the measured ones; the average relative error (ARE) were 7.86%, 6.98% and 8.07% for mass of 70, 110 and 150 kg, respectively; Determination coefficient (R2) were 0.9707, 0.9692 and 0.9697 for mass of 70, 110 and 150kg, respectively. The ARE were 7.45%, 7.91% and 8.73% for spring constant of 16, 20 and 25 N/mm, respectively; the R2 were 0.9767, 0.9720 and 0.9603 for spring constant of 16, 20 and 25 N/mm. This study provides valuable information for the development and improvement of no-till planter in the Northeast ridge zone in China.