小白菜复式播种机犁旋辊压驳岸型种床起垄装置研究

Design of Plow-rotary and Roll-forming Revetment Style Seed Bed Ridging Device of Combined Precision Seeder for Brassica chinensis

针对长江中下游地区小白菜直播作业时,因土壤含水率波动大导致播种机后托板起垄种床厢面不平整的问题,提出了适应小白菜生长的犁耕开沟、旋耕碎土和主动辊压式起垄与平整结合的联合耕整作业方案,结合小白菜种床合理构建技术及大田旱作耕整作业要求,设计了一种小白菜复式播种机犁旋辊压驳岸型种床成型装置。根据土壤挤压和垄体曲面成型原理,分析了种床辊压成型的动力学原理,确定了起垄辊的主要结构和工作参数。田间起垄试验表明,整机作业速度为2.0~5.0 km/h,作业后垄体的垄高合格率、垄顶宽合格率和垄间距合格率分别为90.00%、93.33%和96.67%;双垄垄顶处的土壤坚实度稳定性系数均不低于92.36%,双垄垄壁处的土壤坚实度稳定性系数均不低于92.53%;垄顶厢面地表粗糙度的最大差值为2.19 mm。采用驳岸型种床装置垄播的小白菜单行苗数变异系数及各行苗数一致性变异系数均低于10%,满足小白菜直播农艺要求。

In order to solve the problem of uneven seedbed surface caused by the fluctuation of soil moisture content during Brassica chinensis direct seeding in the Mid-lower Yangtze River,a combined soil preparation of plowing,rotary tillage,ridging and compaction was proposed to adapt to the growth of Brassica chinensis.By combining the cultivation technology of Brassica chinensis seedbed and field tillage operation requirements,a plow-rotary and roll-forming revetment style seed bed ridging device of combined precision seeder for Brassica chinensis was designed.According to the principle of soil compaction and ridge surface forming,the dynamics of seedbed roll forming was analyzed to determine the main structure and working parameters of the ridging roll.The results showed that the qualified rate of ridge height,ridge top width and ridge spacing were 90.00%,93.33%and 96.67%,respectively,when the operating speed of the machine was 2.0~5.0 km/h.And the stability coefficient of soil firmness at the tops and sides of the double ridges were no less than 92.36%and 92.53%.The maximum difference in surface roughness of the ridge top surface was 2.19 mm.The variation coefficient single row seedling number and variation coefficient of each row seeding number were both less than 10%when the device was used to achieve precision sowing of Brassica chinensis.The operating effects met the agronomic requirements of Brassica chinensis direct seeding and provided reference for Brassica chinensis sowing mechanization on ridge.