麦茬地免耕播种机切秸破茬种床整理装置设计与试验

Design and Experiment of Straw Cutting, Stubble Breaking and Seed Bed Preparation Device for No-till Seeders in Wheat Stubble Fields

摘要:

针对黄淮海两熟区麦茬地留茬高、根茬难破碎，玉米免耕播种机种床整理部件易缠绕、拥堵，导致种床不平、播种质量差等问题，本文基于“根茬切割破碎移位”思路设计了切秸破茬种床整理装置，采用同轴上下分布的动定刀组合式根秸切割装置和根茬破碎移位装置，实现地上高留茬根秸切断和根茬破碎移除。基于滑切原理，以对数螺旋线和阿基米德螺旋曲线设计根秸切割动、定刀和根茬破碎移位刀刃口曲线，并通过动力学分析确定根秸切割动、定刀和根茬破碎移位刀结构参数。选取机具前进速度、根茬破碎移位刀入土深度、装置转速为试验因素，以种带清秸率和种带宽变异系数为试验指标设计三因素三水平正交旋转组合试验，建立各因素与指标的回归模型和响应面数学模型。田间试验结果表明，最优参数组合为机具前进速度9km/h、根茬破碎移位刀入土深度70mm、装置转速515r/min，此时种带清秸率为92.59%，种带宽变异系数为7.77%，机具通过性合格，满足黄淮海两熟区玉米免耕播种机作业要求。研究结果为玉米免耕播种机种床整理装置设计与优化提供参考。

Abstract:

In order to solve the problems of high stubble residue in the Huang-Huai-Hai double-cropping area, the stubble-residue is difficult to break in the process of no-tillage sowing of maize, which leads to the winding and congestion of the bed preparation device, thus dragging and pushing soil, resulting in uneven sowing bed and poor sowing quality. Based on the idea of “root stubble cutting, crushing and shifting”, a straw cutting, stubble breaking and seed bed preparation device was designed. The coaxial upper and lower distributed moving and fixed knife combined root stubble cutting device and the root stubble crushing and shifting device were adopted to achieve the cutting of high stubble left above ground and the crushing and removal of root stubble in wheat. Based on the sliding cutting principle, the blade curves of the dynamic and fixed combined root straw cutting cutter and the root stubble crushing and shifting cutter were designed by logarithmic helix and Archimedes helix curve, and the structural parameters of the dynamic and fixed combined root straw cutting cutter and the root stubble crushing and shifting cutter were determined through dynamic analysis. The forward speed of the machinery, the depth of the root stubble crushing and shifting cutter into the soil, and the rotational speed of device were selected as the test factors, and the straw clearance rate of the seed bed and the coefficient of variation of the seed bed width were taken as the test indicators to conduct the three-factor and three-level orthogonal rotation combination test. The regression models and response surface mathematical models of each factor and indicator were established. The test results showed that the optimal parameter combination was as follows: the forward speed of the machinery was 9km/h, the depth of the root stubble crushing and shifting cutter into the soil was 70mm, and the rotational speed of device was 515r/min. At this time, the straw removal rate of the seed belt was 92.59%, the coefficient of variation of the seed belt width was 7.77%, and the machinery pass rate was qualified, meeting the operation requirements of the no-tillage planter for corn in the Huang-Huai-Hai two-cropping area. The research result can provide a reference for the design and improvement of the seed bed preparation device of the no-till seeding machine for corn in plots with high stubble retention.