犁旋组合式油菜直播机扣垡装置设计与试验

针对长江中下游稻油轮作区油菜直播作业时,因前茬水稻留茬高、秸秆量大而导致旋耕部件作业耕深浅、秸秆埋覆率低的问题,结合油菜根系生长对直播的农艺要求,提出犁耕与旋耕组合的联合耕整方案,设计一种与油菜直播机配合,通过先抬、后扣的作业方式,实现高茬粘重土壤有序翻埋的扣垡装置,并集成了犁旋组合式油菜直播机。分析阐述了扣垡犁曲面形成原理,确定了其关键影响因素导线、元线角、母线的数学模型,构建了土垡与扣垡犁力学模型,阐明了犁体曲面扣垡过程。为验证扣垡装置功能,在高茬秸秆工况下开展扣垡犁单体试验,试验结果表明,扣垡犁平均扣垡率为93.41%,具有较好的扣垡埋茬功能。以设计的犁旋组合式油菜直播机与仅有旋耕装置的油菜直播机分别在秸秆留茬高度为338、452 mm工况下进行了田间对比试验,2种工况下,犁旋组合式直播机相对仅有旋耕装置的油菜直播机的耕深分别提高了137、110 mm,秸秆埋覆率分别提高了33.94、28.36个百分点,种床耕整效果优于仅有旋耕装置的油菜直播机,作业质量满足油菜播种要求。该研究可为犁旋组合式耕整机和犁体曲面优化设计提供参考。

Design and Experiment of Plowing and Rotary Tillage Buckle Device for Rapeseed Direct Seeder

To overcome the defects like shallow plough layer and low stubble burying rate caused by the high stubble and large amount of straw after rice harvesting when the rapeseed direct seeder works in the rice-oil rotation area of the middle and lower reaches of the Yangtze River,a tillage scheme that combined plowing and rotary(P&R)tillage was put forward based on the agronomic requirements of rape plants.A type of buckle device that could lift and then buckle the soil was designed for the rapeseed direct seeder to realize the orderly burying of high stubble and sticky soil.In addition,the rapeseed direct seeder integrated with plowing and rotary tillage was developed.The formation principle of buckled plow surface was expounded.The mathematical models of guiding curve,element angle and generatrix were determined.The mechanical models of the soil ridge and buckling plow were constructed.The buckling process of the plow body surface was clarified.In order to validate the function of buckle device,the test of single plow was carried out under the condition of high stubble.The results showed that the average buckling success rate of the plow was 93.41%,which achieved the desired performance.Field contrast experiments,under the condition that the stubble height were 338 mm and 452 mm,respectively,were carried out between the seeder with P&R tillage and the seeder with rotary tillage only.Under the two conditions,the plowing depth of the seeder with P&R tillage was increased by 137 mm and 110 mm,respectively,and the stubble burying rate was increased by 33.94 percentage points and 28.36 percentage points,respectively.The seed-bed performance of the seeder with P&R tillage whose operation quality met the requirements of rape sowing was better than that of the seeder with rotary tillage only.The research result provided reference for the design of combined tillage machine and plow surface.