免耕播种机偏转侧滑式防堵开沟器研究

发布时间：2018-01-08 14:33

本文关键词：免耕播种机偏转侧滑式防堵开沟器研究　出处：《中国农业大学》2016年博士论文　论文类型：学位论文

【摘要】：在我国一年两熟区播种小麦时,地表秸秆覆盖量大、土壤紧实,对免耕播种机提出更高的要求。当前,我国免耕播种机主要是通过动力驱动装置实现秸秆防堵、切断秸秆残茬、创造出种床环境,但其所需的动力较大、结构复杂、土壤破坏严重,不适于我国中小型免耕播种机的作业,也不利于作物生长。因此,本文针对我国中小型免耕播种机作业的需要,研制了可创造良好种床环境且具有耐磨减阻、防堵性能的滑动式开沟器。主要结论和研究成果如下：(1)通过设计不同结构参数的滑动式开沟器进行田问试验,确定铲尖不同结构参数(入土角、刃口曲线、入土隙角、刃口厚度)与种床环境(土壤容重、种沟截面积、表层秸秆扰动量)及作业能耗等指标的关系。通过多目标优化模型综合评价对种床特性、作业能耗的影响,得到滑动式开沟器的最优结构参数：入土角55。、凹线型刃口曲线、入土隙角4。及较小的刃口厚度。(2)通过仿真分析和田间试验,得到滑动式开沟器在开沟作业时的关键受力和磨损部位为铲尖顶端和刃口,且铲尖顶端的磨损最为严重。在铲尖磨损特性分析和结构参数优化的基础上,提出铲尖可替换要求—由于铲尖各部分的磨损是不可避免的,将铲尖磨损严重的顶端和刃口分别设计为可替换结构,从而减少开沟器结构的磨损;提出刃口减少对土壤扰动、磨损和降低阻力的要求一设计的刃口曲线的前段圆弧所在圆的直径比后段圆弧的大,减少土壤对刃口表面正压力,进而减小作业阻力和磨损。所设计刃口曲线的方程分别为：前段刃口的曲线方程(x-225)2+(y-389.7)2=202500、后段刃口的曲线方程(x-18.51)2+(y-140.59)2=14400。(3)在对秸秆覆盖形式和堵塞方式分析的基础上,明确适于滑动式开沟器作业的秸秆覆盖条件。通过滑动式开沟器铲柄对表层秸秆的扰动和受力分析,明确秸秆的运动规律,建立秸秆堵塞模型。对模型中影响秸秆滑动的因素进行分析,得出在铲柄前端堆集的秸秆会滑到种带两侧并产生侧滑效果,侧滑受表层秸秆覆盖情况的影响较大。(4)在秸秆堵塞模型分析的基础上,提出秸秆侧滑防堵的思路；设计了秸秆偏转侧滑防堵装置。根据产生侧偏效果的要求,合理设计了“铲柄—弹簧—侧偏板”的结构。通过偏转侧滑防堵装置的工作原理分析和铲柄对秸秆的扰动试验,确定偏转板的宽度和高度分别为80mm、150mm;选择回位弹簧的参数：线径1mm、外径10mm、长度26mm。(5)在以上理论和试验分析的基础上,确定免耕播种机偏转侧滑式防堵开沟器的整体结构和关键参数,并对其进行田间试验。试验结果表明：开沟作业后的土壤扰动量满足作业要求;对土壤水稳团聚体的破坏不明显,减少对种床土壤的破坏,有利于作物生长；铲尖的磨损主要集中于铲尖顶端的可替换板处,且减少对上端刃口的磨损量；在秸秆全量粉碎覆盖的条件下,秸秆扰动宽度和清除率分别为15.9cm、74.47%,未出现堵塞现象。所设计的该免耕防堵开沟器,满足中小型免耕播种机的作业要求。
[Abstract]:In China a year planting areas of two crops of wheat, straw covered a large amount of soil compaction, put forward higher requirements for no tillage planter. At present, no tillage planter in China is mainly realized by straw blocking power driving device, cutting stubble, create a bed environment, but the required the power of large, complex structure, soil destruction, not suitable for small and medium-sized planter work, is not conducive to the growth of crops. Therefore, we need to work for small and medium-sized planter, is developed to create a good environment and a bed with wear-resistant drag reduction, anti sliding opener blocking performance the main conclusions are as follows: (1) sliding opener through the design of different structural parameters of field experiment, determine the shovel tip of different structural parameters (penetration angle, blade curve, ground clearance angle blade, thickness) and bed environment (soil bulk density, A channel section area, surface disturbance and straw) operation energy consumption index. The multi-objective optimization model of comprehensive evaluation on clinical characteristics, effect of energy consumption, the optimal structure parameters of sliding type opener: penetrating angle 55., concave linear cutting edge, edge thickness in 4. and smaller clearance angle. (2) through the simulation analysis and field tests, by sliding the opener key in ditching the force and wear parts for the top edge and shovel, shovel and the wear top is the most serious. On the basis of shovel tip wear characteristics analysis and structural optimization on the proposed shovel tip can replace the requirements due to wear shovel tip of each part is inevitable, the wear of the shovel tip top and edge were designed as replaceable structure, thereby reducing the wear of the opener structure; put forward edge to reduce soil disturbance, and reduce the wear resistance A design of the cutting edge curve of anterior arc the diameter ratio after arcs, reduce the blade surface pressure soil, then reduce the work resistance and wear. The design of cutting edge curve equation respectively: front edge curve equation (x-225) 2+ (y-389.7) 2=202500 curve equation after the blade (x-18.51) 2+ (y-140.59) 2=14400. (3) based on straw mulching and clog mode analysis, clearly suitable for operations in sliding opener of straw mulching conditions. By sliding the opener shank on the surface of straw disturbance and stress analysis, clear straw movement pattern. The establishment of the straw blocking model. The influence factors of straw sliding model is analyzed, the front part of the shovel shaft heap of straw will slide with both sides are affected by surface sideslip sideslip effect, the straw cover larger. (4) in the straw block Based on the model analysis, put forward the idea of anti blocking straw sideslip; design of straw sideslip anti blocking device. According to the deflection produced side effect, reasonable design of the structure of the shovel handle spring side plate ". Through the analysis of working principle of anti slip deflection and a shovel handle blocking device disturbance test on straw the determination of deflection plate width and height are respectively 80mm, 150mm; select the parameters of the return spring: diameter 1mm, diameter 10mm, length 26mm. (5) based on the above theoretical and experimental analysis, determine the overall structure and key parameters of blocking the opener of no tillage planter deflection and sideslip prevention. In the field experiment. The experimental results show that the soil disturbance after ditching operations to meet the operational requirements of soil water stable aggregates; the damage is not obvious, reduce the bed soil destruction, is conducive to crop growth; shovel tip wear mainly On top of the shovel plate can be replaced, and reduce the amount of wear on the upper edge of the cover; grinding conditions in the straw, straw disturbance width and clearance rate were 15.9cm, 74.47%, was not blocked. The design of anti blocking tillage opener, to meet the operational requirements of small and medium and no tillage seeding machine.

【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S223.2

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