Improving uniform scattering device for straw-smashing,back-throwing,no-tillage planter under complete straw mulching condition

With the objective of obtaining a completely straw-mulched field,when no-tillage mechanical sowing is implemented with straw smashing,delivering,and back-throwing approaches,it may be difficult to scatter the smashed straw uniformly during a succeeding wheat sowing step.This is because the previous rice straw is substantial in quantity and has a high humidity and toughness,which may easily result in non-uniform straw mulching and thus sparse and weak seedlings of wheat.Therefore a force-dispersing and uniform-scattering device was designed.With the number of scattering impellers,impeller angle,and impeller rotation speed as the main factors and the percentage of pass for the scattering width and non-uniformity of the straw mulching as the assessment indices,single-factor experiments and orthogonal regressive tests were performed,and a dual-index(percentage of pass for the scattering width and non-uniformity of the straw mulching)fitted regression equation was established.The test results suggested that the main factors(from primary to secondary)that influence the indices were the impeller rotation speed,number of scattering impellers,and impeller angle.The optimal parameter combination for the uniform scattering device was four rows of impellers with an angle of 15°,rotation speed of 1015 r/min,percentage of pass of 72.65%for the scattering width,and a non-uniformity of 13.8%in the straw mulching.This combination can be used to realize a uniform scattering of the smashed straw along the seedling rows on the after-sowing ground.According to the field investigation of the wheat growth,the wheat emergence rate was 90.7%.The research results can provide a reference for improving the uniform scattering device for a straw-smashing,back-throwing,no-tillage planter for obtaining a completely straw-mulched field,enhancing the quality of the machinery operation,and ensuring good and strong seedlings after sowing.

Stalk cutting mechanism of no-tillage planter for wide/narrow row farming mode

A no-tillage planter of narrow row spacing was designed according to the agronomic requirements of wide/narrow row farming mode in the black soil region of Northeast China.Due to the narrow spacing of the seeder unit,a gear-tooth stalk cutting mechanism was designed in order to prevent residues from blocking the planter.The basic parameters,number and edge curve of the stalk cutting blade were designed and optimized.Three-factor and three-level combined orthogonal experiments were conducted using the factors of working speed(1.12 m/s,1.57 m/s and 2.02 m/s),tillage depth(75 mm,90 mm and 105 mm)and cutter spacing(15 mm,30 mm and 45 mm),which significantly affected stalk cutting rate and soil disturbance rate.The optimal combination is the working speed of 1.62 m/s,tillage depth of 92 mm and cutter spacing of 35 mm.Under this condition,the stalk cutting rate is more than 90%and soil disturbance rate is 7.5%-12.0%.The performance of the new no-tillage planter was tested by using the above parameters.The results showed that the no-tillage planter of narrow row spacing came up to the relevant national standards in China.

Friction wheel transmission of no-tillage corn planters

To overcome the unfavorable factors of ground wheel-driven chain transmission when a no-tillage planter operates on straw mulching fields,a friction wheel transmission based on ground wheel transmission was designed in this research.The stability,i.e.,the effects of friction wheel tyre pressure on stability of machine transmission was investigated via validation of main factors.The relationships among tyre pressure,deformation and load were determined via theoretical analysis.The tyre pressure extreme for transmission is 25.90 psi,the maximum pressure imposed on the friction wheel tyre is 14 kN,the maximum deformation of friction wheel is 8.7 mm.The stabilities of friction wheel slip rate and seeding distance were investigated via field tests and alteration of friction wheel tyre pressure.After processing the test data,it can be found that the minimum tyre pressure for acquisition of friction wheel slip rate was 24.35 psi.After processing the data of seeding distance,it can be validated that the tyre pressure was kept unchanged following the optimal transmission effect of the transmission through the abrupt change of working speed,which further proved the feasibility of the new friction wheel transmission.The transmission of friction wheel can reduce 14.67%in variation coefficient of seed spacing at the speed of 5 km/h,and 16.22%at the speed of 8 km/h.

Optimization and experiment on key structural parameters of no-tillage planter with straw-smashing and strip-mulching

Accelerate the quality of smashed-straw laying and enhance the effect of seed-bed arranging for no-tillage planter with straw-smashing and strip-mulching in full stubble covered paddy have become imperative in implementing modern conservation tillage.Considering the perfect operating performance(passability and stability)of the developed no-tillageplanter,this study intends to optimize the structure design of smashed-straw diversion device and strip-rotary tillage device.Dynamics equations of smashed straw and kinematics models of rotary blades were established through theoretical analysis,and the principal factors that affecting straw strip-laying quality and seed-bed arranging effect were specified.The influence of out-enlarge angle(η)and slide-push angle(γ)of the diversion device on the coefficient of variation(ζ1)of cover-straw width,and the influence of rotary tillage-blade number(N)and configuration in a singlerotary plane on the broken rate(ζ2)of strip soil were completely analyzed.And then,based on the systematic analysis and integrated scheme,operating performance and field verification tests using the optimized no-tillage planter were thoroughly performed.The results of the performance tests indicated that the out-enlarge angle(η)had a highly significant influence on the coefficient of variation(ζ1),and the slide-push angle(γ)had a significant influence on(ζ1).The rotary tillage-blade number(N)had a highly significant influence on the broken rate(ζ2),and the slide-push angle(γ)had a significant influence on(ζ2).The obtained optimal combination of these key structure parameters through comprehensive analysis wasη=45°,γ=40°,and N=4.Field verification test results indicated that the optimized no-tillage planter achieved mean values of ζ1=10.47%and ζ2=90.95%,which satisfied the relevant operation quality and cultivation agricultural requirement of conservation tillage equipment,and provided technical references for developing the similar no-tillage planter of straw crushing and returning.

打穴播种机研究的发展与现状

在现代农业种植业生产中，为了改良土壤和提高土壤肥力，种植工艺不断更新，少耕、免耕、地面覆盖和秸秆还田等措施正在推广，对农业种植机械的适应性提出了新的要求。本文在分析打穴播种工艺特点的基础上，阐述了打穴播种机研究的发展并分析了各种机具的特点及其存在的问题，提出了打穴播种机研究工作的重点和需要解决的问题。

勺匙式玉米精量取种器的设计与试验

为实现玉米精量播种,设计了一种适用于穴播轮的新型勺匙式取种器。在确定了取种器关键参数后,对其工作原理和过程作了分析,得出了影响勺匙式取种器性能主要因素和临界条件。以导种管弯角、容种高度和机组行走速度为因素,以单粒率、空穴率为指标进行了正交试验,通过试验数据分析可知,使勺匙式取种器性能最佳的参数组合是:导种管弯角90°、容种高度为穴播轮半径的2/3、速度0.86m/s。试验结果表明,勺匙式取种器满足玉米精量播种的要求。

铲式玉米精密播种机振动特性模型建立与试验

为了研究铲式玉米精密播种机播种性能与农田不平度激励产生振动之间的关系,推导了稳态响应与理论粒距关系数学模型。由建立的数学模型得出铲式玉米精密播种机的播种性能主要由播种机的结构特征、播种机工作速度、倾斜圆盘勺式玉米精密排种器与耕作土壤表面间的距离、土壤不平度和土壤粘性决定。理论粒距与实际粒距的对比结果表明,两者分布趋势基本相同,建立的稳态响应与理论粒距关系数学模型可用于对工作状态下播种机的播种性能进行预测和分析。

铲式成穴器成穴机理及影响因素的分析

在分析铲式成穴器的结构特点和工作过程的基础上，建立了打穴铲运动轨迹的数学模型并分析了打穴铲的运动规律和成穴机理。进而分析了成穴器结构参数对打穴铲在土壤上所形成穴孔长度和穴孔宽度的影响。试验结果表明，穴孔长度随着水平倾角和垂直倾角的增加而增加。

2BQHM-2型花生覆膜穴播机的设计与试验

【目的】较好地实现花生膜上成穴、播种作业.【方法】针对花生覆膜穴播机存在的技术问题,进行2BQHM-2型气吸式花生覆膜穴播机优化设计与制造;对其关键工作部件结构及作业参数进行理论分析,然后利用UG设计分析软件完成组成部件的优化设计;通过虚拟样机技术对该机进行虚拟装配,并对成穴过程进行运动仿真分析,检验各组成部件设计的合理性及使用效果.【结果和结论】典型地区花生垄作覆膜播种田间作业性能试验表明,该机工作性能较为稳定,各部件作业顺畅,各项作业指标均能较好地达到技术要求,其作业效果与虚拟仿真测试结果相符,研究结果为覆膜穴播机的进一步优化设计提供了理论依据及技术参考.

铲式成穴器成穴性能的试验研究

根据铲式成穴器的成穴机理确定了其结构参数和工作参数的设计变化范围，并按照二次回归试验设计方法进行了成穴器参数对成穴性能影响的试验。通过对试验结果的统计分析，查明了成穴器参数对穴孔长度、穴孔宽度。

播种机参数和打穴铲结构对投种影响的计算机仿真

根据铲式成穴器与倾斜圆盘勺式排种器组合设计成的打穴播种机的结构特点，建立了种子下落过程中运动轨迹的参数方程。以此为基础分析了播种机双向倾角、排种器投种角和打穴铲结构参数对种子在打穴铲内自由下落过程的影响，进而确定了打穴铲几何尺寸的设计原则。

铲式播种机数字化设计实例检索策略研究

在基于实例推理的机械系统数字化设计过程中,实例的检索策略和检索方法对于检索的有效性和可靠性具有决定性影响。结合面向对象的实例表达方法,研究实例检索过程中机械零部件特征属性相似度的确定方法,提出将模糊数学、灰色关联分析应用到特征属性相似度的计算中。引入层次分析法和基于相似度离差信息方法确定特征属性的组合权重。以铲式播种机设计为例,验证了所提出的实例检索算法具有良好的实例分辨能力和检索成功率。

联合作业穴播机的设计

针对目前穴播机械的现状,设计了一种新型的联合作业穴播机,能够集土壤整平、覆膜、打穴播种、膜上覆土于一体。穴播器、整平机构、覆膜机构均具有创新性,并分析了其具体的结构设计方案。实验表明,该机作业性能良好,各项作业指标均符合标准要求,适用范围广泛,可满足棉花、花生、玉米、小麦等大粒和小粒种子的播种作业,成穴器后开式设计有效地解决了传统穴播机械的堵土问题。

冲孔免耕穴播机入土成穴原理的研究

将传统的条播免耕播种改为穴播播种,优化和改进了现有穴播机的结构,并研制了一套施力机构,以帮助成穴器入土.对成穴器入土成穴条件进行了理论分析,证明此机构能够解决穴播器在免耕地上的入土成穴问题,为冲孔免耕穴播机的研究设计提供了依据.

铲式玉米精密播种机振动对播种质量影响的试验

为了研究铲式玉米精密播种机振动对播种质量的影响,在3种不同的播种速度下利用3种玉米种子进行了播种试验;分析了播种机工作过程中的振动特性,以自功率谱密度表明了播种机工作状态下不同频域的振动强度,结果表明,播种机工作时主要为低频振动,并且播种机的振动强度随着播种速度的增加而增强。同时,以播种时的种距变异系数和重播率为试验指标,分析了播种机振动对播种质量的影响。试验结果表明,种距变异系数和重播率随着播种机振动强度的增加呈非线性增大。

覆膜穴播机三刚一柔成穴机构的设计及仿真

针对我国覆膜玉米穴播机采用的平行四杆成穴机构作业时垂直入土扰动大、撕膜严重的问题,设计了三刚一柔成穴机构,主要将平行四杆机构从动杆换装为弹簧阻尼杆。基于Adams建立三刚一柔成穴机构和平行四杆机构仿真模型,并在相同条件下进行仿真,结果表明:三刚一柔成穴机构的成穴杆在x轴水平方向较平行四杆机构位移变化较小且平滑,在y轴垂直方向趋势一致;三刚一柔成穴机构的成穴杆对前后土型均有扰动,但扰动力均较小,而平行四杆机构只对前边的土壤有扰动,但扰动力是三刚一柔机构的9.4倍。因此,所设计的三刚一柔成穴机构较平行四杆机构对土壤扰动小,有利于种子发芽,成穴杆不受力时又可恢复至垂直入土的状态,对地膜破坏较小。

铲式玉米精密播种机仿真及虚拟设计研究

为了克服传统播种机在地表覆盖和免耕条件下开沟播种中存在的问题,将铲式成穴器与倾斜圆盘勺式玉米精密排种器组合设计成铲式玉米精密播种机。在对铲式成穴机构成穴机理进行理论分析的基础上,实验研究了成穴器参数对成穴质量的影响,建立了穴孔长度、穴孔宽度和穴距与成穴器参数间关系的回归方程,并通过计算机仿真技术模拟分析了打穴铲的运动规律,为成穴器的设计提供了依据。通过实验研究建立了排种器排种质量与参数间关系的数学模型,并对参数进行了优化。利用Pro/E建模和装配,对铲式播种机进行了虚拟设计,并采用ADAMS对其工作过程进行了动态仿真。进而采用神经网络优化技术,确定了播种不同玉米种子时播种机的优化参数,为铲式玉米精密播种机的设计提供了系统的理论和方法。

铲式玉米精密播种机的运动仿真

在铲式玉米精密播种机的结构和特点分析的基础上,利用Pro/E和ADAMS对铲式玉米精密播种机的运动进行了仿真分析。分析结果表明:打穴铲在运动过程中做空间螺旋摆线运动。在打穴铲进入土壤过程中,铲的外侧面向侧向挤压土壤并进入土壤中,保证了打穴铲内侧面铲端处的开口不与所形成穴孔的土壤侧壁相接触,从而避免了成穴部件被土壤堵塞的问题;播种机投种过程中种子从打穴铲左上方进入,而从右下方投出,因此应使打穴铲左侧端面倾斜,并适当地将打穴铲在铲轮上的安装位置顺时针稍微偏移。

多功能小麦覆膜穴播机的设计

设计了一种新型的覆膜穴播机,能够集土壤整平、覆膜、打穴播种、膜上覆土于一体,实现联合作业。其关键部件穴播器、仿形整平器、排种系统和覆土机构均具有创新性,并分析了其具体的结构设计方案。试验表明,该机作业性能良好,各项作业指标均符合标准要求,能够适用于小麦等小粒种子的播种作业,解决了传统轮式播种机的堵土问题。

铲式玉米精密播种机三维参数化设计

针对铲式玉米精密播种机传统设计方法中存在的设计效率低、无法进行动态装配等问题,应用Pro/E软件对播种机零部件进行了三维模型构建,并完成播种机的整体装配;在VisualC++平台上,利用Pro/TOOLKIT和MFC,编制了基于Pro/E的三维参数化设计软件,利用程序控制语句对播种机模型进行驱动,实现了播种机的参数化和系列化设计,为播种机的运动学、动力学和有限元分析奠定了基础。