Design and experiment of the pneumatic double disc precision seed metering device for Chinese flowering cabbage

Single seed metering devices for Chinese flowering cabbage planting machines have suffered such deficiencies as low efficiency,poor accuracy,and instability.To overcome these limitations,a pneumatic double disc precision seed metering device was designed.This innovative device can simultaneously plant four rows,considering the specific agricultural requirements and the geometric characteristics for Chinese flowering cabbage seeds.The precise parameters of the key component seed disc were derived through theoretical calculation.In addition,a detailed account was given for the working principle and workflow of the seed metering device.The discrete element method and EDEM software were employed to optimize the seed disc by exploring the effects of seed disc rotational speed and interleaving seed slots on seed viability.Orthogonal rotation experiments were conducted to evaluate the impact of seed disc rotational speed and negative pressure.While rates of qualified seeding,double seeding and missing seeding were adopted as test indicators.Testing results show that,at a seed disc rotational speed of 41.5 r/min and a negative pressure of 3.80 kPa,the average qualified seeding rate is 90.13%,the average missing seeding rate is 3.30%,and the average double seeding rate is 6.02%.These values satisfy the agricultural requirements for planting Chinese flowering cabbage.The findings can also provide valuable insights for the structural optimization and design of precision seed metering devices for Chinese flowering cabbage.

Vacuum and Air Flow for 2QXP-1 Vacuum Precision Seed Metering

Vacuum precision seed metering is the key part of vacuum seed planter. Planting performance of planter is affected by vacuum and air flow which are important parameters for choosing fan. Effects of qualification percent and miss percent on air chamber vacuum 3, 4, 5 and 6 kPa were studied at different operating speeds. The results showed that operating performance of the seed metering was excellent when air chamber vacuum was 5 and 6 kPa, which air flow was 7.4-8.0 m3·s-1 and 8.0-8.8 m3·s-1 , respectively.

Determination of Some Design Parameters for Roller Type Seed Metering Device

There are many design parameters in precision planters to be considered such as cell diameter, peripheral speed of roller, number of cells, manner of feeding seeds into cell and travel speed. In precision planters each cell must contain only one seed. Therefore, sliding the seed to the cell is important and depends on several parameters such as seed repose angle, seed dimensions and physics of cell. To help the seed to repose in the cell, making a groove on the roller would be very useful. Dimensions of this groove are very important and are considered as basic design parameters. This research was performed to determine some design parameters such as roller speed, travel speed, length and depth of groove for tomato seeds precision planting. In this regard, seeds with a diameter of 4 mm were used. The range of variation was based on calculations obtained. A roller with 42 mm width, 118 mm diameter and 15 cells on the surface was used in the experiment. For each cell, a triangular groove was created on the roller. The groove depth varied from zero at the beginning to the maximum value where the groove connected to the cell. The test unit had a continued and wide belt with 1 l m length. In each replication, planter worked for 20 s to reach a stable state. Thereafter, seeds were allowed to drop on the grease belt. Number of seeds and their spacing were measured on the 4.5 m of the belt. Results showed that the roller speed of 41.5 rpm, the planter travel speed of approximately 1 km/h, groove length of 6-8 mm and groove depth of 1.5 mm can improve planter performance for tomato pelleted seed.

辣椒机械式自动精量排种器设计与试验

辣椒漂浮育苗具有占地面积小、育苗周期短和椒苗品质好的优点,播种环节要求一穴一粒精量播种,通常采用人工点播,存在劳动强度大和播种效率低的问题。针对以上问题,该研究以磁力回位型排种器为基础,设计了一种适于辣椒漂浮育苗的机械式自动精量排种器,并对关键机构进行设计,通过单因素试验获得曲柄直径、曲柄电机工作转速和种量的较优区间,以单粒合格指数、重播指数和漏播指数为指标进行三因素三水平正交试验,建立回归模型,并进行参数优化。试验结果表明,在排种器旋转倾角30°、旋转电机角速度0.07 rad/s(即生产率240盘/h),曲柄直径为30 mm、曲柄电机转速为230 r/min、种量为4千粒时,排种器的播种效果较好,单粒合格指数为91.04%,重播指数为5.21%,漏播指数为3.75%,相比于人工操作磁力回位型排种器,单粒合格指数提升了5.81个百分点,重播指数降低了6.45个百分点,满足辣椒漂浮育苗的播种要求,可为辣椒育苗轻简化生产和小籽粒种子的机械式精量排种器研究提供参考。

正负压气吸式精量排种器设计与试验

为了更好地适配非圆小籽粒种子的播种,解决机械式排种器易伤种,对种子尺寸适应性差的问题,设计了1种正负压气吸式精量排种器。根据农艺要求对排种器整体进行了设计;同时以小麦为研究对象,通过单因素试验,分析了吸种负压、排种器转速以及投种高度3个因素对排种器性能的影响;通过响应面试验,得到了较优的参数组合:吸种负压为-3.5 kPa,排种器转速为19 r/min,投种高度为180 mm;对最优参数下精量排种器进行台架试验,结果表明,合格率为80.62%,重播率为9.22%,漏播率为10.16%。符合JB/T—10293—2013《单粒(精密)播种机技术条件》的要求。

正负气压组合滚轮式油菜精密排种器设计与试验

针对油菜种子粒径小、质量轻,单粒排种难度较大的问题,设计了一种正负气压组合滚轮式精密排种器。阐明了排种器工作原理,开展排种器吸种、携种和卸种环节受力分析和排种滚轮对种群拖带过程解析;提出了通过控制充种区种层高度和种群压力的防拖带堆积机理,设计了一种侧向充种、拖带种子自由回落的充种室结构,利用离散元仿真研究了充种种层高度和充种室结构对排种器充种区内充种性能的影响及对种群拖带堆积的解决情况;仿真结果表明,排种器内种子随着充种种层高度的增大,种群平均动能均值逐渐增大,对种群平均扰动能力逐渐增强;在充种种层高度50 mm条件下,设计的防拖带堆积充种室降低了充种区域底部种群所受的压力,未出现种群拖带堆积现象,且保持了对充种区域种群的扰动作用。在JPS-12型排种器检测试验台上进行了排种器性能试验,结果表明,当排种转速为15~30 r/min、吸种负压为1.0~1.2 kPa时,排种器合格指数均保持在90%以上;设计装配正负气压组合滚轮式精密排种器的播种机开展播种试验,田间实测出苗后株距稳定性变异系数为4.4%,各行苗数一致性变异系数为8.14%;研究结果表明设计的排种器满足精密播种要求。

Study on multi-size seed-metering device for vertical plate soybean precision planter

Aiming to solve the problem of small range of the appropriately sowing seeds existing in a vertical disc seed-metering device,the planter plate series with four sizes were developed according to the variety and size distribution of all soybeans in China.The structure and working principle of the vertical disc soybean seed-metering device were detailed,and the influence of the diameter of soybean on the working performance of the seed-metering device was analyzed through the software EDEM virtual simulation,so as to achieve the goal of covering the soybean seeds with all sizes by the minimum planter plate series as well as to obtain the most appropriate operating speed of each planter plate by optimization.For the planter plates with the hole diameter of 7,9,12,16 mm,the appropriate size ranges of sowing seeds are 4.5-6.0,6.0-8.0,8.0-10.5,10.5-13.0 mm,respectively,and the appropriate operating speeds are 9,8,7,6 km/h,respectively.The results show that this planter plate series can meet the requirements of seeding with all sizes of soybeans at the range of the most appropriate operating speed.The study method can provide a reference for design and optimization of precision planters.

气力式高速精量排种器研究现状及展望

高速作业是当前精量播种技术的发展趋势,气力式精量排种器是实现高速作业的关键技术载体。分析限制气力式排种器作业速度提升的主要因素,提出高速充种技术、稳定清种技术、投种过程种子平稳运动控制技术、排种器平稳驱动技术四项关键技术。综述气力式精量排种器主要类别及特点,梳理国内外气力式排种器研发应用现状,针对提出的四项关键技术分析国内外研究现状,得出稳定充种、有效清种、平稳投种、排种器平稳驱动是有效提升高速作业播种合格率、降低变异系数、保证粒距均匀性的主要技术措施。结合我国的情况分析高速精量播种存在作业速度及效率低、电驱技术及质量监控技术不完善等问题,提出气力式高速精量排种器需要加大自主创新,未来向着高精度、高效率、智能化方向发展。

双轨道弹射式水稻精量直播排种器设计与试验

针对现有排种器存在投种不顺及大播量成穴性较差等问题,本文设计了一种双轨道弹射式水稻精量直播排种器。基于理论分析设计了关键部件,利用DEM-MBD耦合仿真技术得到了弹簧力参数及因素取值范围,明确了转速超过35 r/min后排种器的性能显著下降。以合格率、漏播率及重播率为性能评价指标开展台架正交试验,研究转速、调节深度及稻种球度对排种器工作性能的影响,建立排种性能评价指标的回归预测模型。试验结果表明:排种轮转速为23.06 r/min、型孔深度为8.99 mm、稻种球度为52.7%时,排种器合格率为88.58%、漏播率为4.43%、重播率为6.99%,排种器工作性能最佳。为验证排种器工作性能及优化后参数的准确性,开展了田间试验,试验结果与优化后结果保持一致,回归方程预测结果误差小于2%,验证了试验可行性及参数准确性,在最优参数下排种器穴径合格率为100%、平均穴径为3.62 cm、穴径变异系数为18.45%、平均穴距为22.98 cm、穴距变异系数为8.43%、平均穴粒数为11.08、穴粒数变异系数为17.56%。所设计的排种器具有较好的播种性能、较高的穴径合格率及较低的变异系数,表明该排种器具有良好的成穴性能。

一器三行小青菜精量排种器设计与优化

为改善我国传统的单行和双行播种模式所面临的播种效率低下的问题,以“上海矮箕”小青菜种子为研究对象,设计一种新型的一器三行精量排种器,并对排种器的工作原理进行分析。通过相关数学理论计算出所设计排种器关键部件的相关参数。利用FLUENT软件对排种器内部气流场进行分析,确定最佳的吸孔数目。将负压、排种盘角速度以及吸孔锥角作为试验因素,以排种器进行排种时的合格率以及漏播率作为性能指标,开展CCD二次旋转正交组合试验。当负压为-2.16 kPa,排种盘角速度为29.43 r/min,吸孔锥角为61.51°时,内圈合格率为95.12%,漏播率为3.67%,中圈合格率为94.68%,漏播率为3.12%,外圈合格率为94.24%,漏播率为2.58%。进行台架试验和田间试验验证所得最佳组合参数的合理性。

白萝卜气吸式精量排种器结构设计与分析

为满足白萝卜机械种植要求,解决我国西南地区缺乏相关种植机械问题,设计了一种气吸式精量排种器。通过计算与理论分析,设计了排种器关键结构参数;对充种、携种和投种阶段种子受力进行分析,确定了影响播种性能的主要因素。利用Fluent软件仿真模拟不同型孔尺寸参数对负气压室气流影响,确定了最佳型孔直径参数,其型孔直径范围为2.079~2.178 mm。通过参数优化得到最佳参数组合为:排种盘直径200 mm、型孔分布直径160 mm、型孔个数16个、型孔直径2.2 mm。排种性能台架试验结果表明,在工作转速为30.54 r·min^(-1),负气压室气压为6.58 kPa,排种器单粒合格指数95.61%,漏播指数为0.64%,重播指数为2.04%。该研究结果有助于提高播种器性能,为白萝卜精量播种机器设计与制造提供可靠参考。

小粒径蔬菜精密排种器研究现状及展望

精密播种技术作为精准农业在播种领域的延伸,在降低播种用种量、提升作业质量上有着重要作用。精密播种机最关键部件是精密排种器,排种器的性能指标直接影响到播种作业的优劣。对国内外现有精密排种器的研究现状进行分析,总结现有精密排种器存在问题,对未来精密排种器的优化提出建议。

交错勾齿式小麦精量排种器设计与试验

针对小麦精量播种需求以及现有排种器脉动性高、均匀性差的问题,设计了一种4排交错勾齿式小麦精量排种器,利用勾齿式型孔单粒囊种,并通过勾齿交错布置使下落的种子流形成交错有序的种子面,减少种子间的碰撞重叠,提高种子的有序性。通过对充种过程中小麦种子姿态分析,确定了型孔的关键结构参数和曲线轮廓。运用离散元法EDEM,分析了排种轮转速和充种区域夹角对充种性能的影响规律。仿真结果表明,排种轮转速对充种时处于有利姿态的种子数量有显著影响,充种区夹角的增大有利于提高充种率,但充种区夹角过大会造成成功充入种子掉落出型孔,降低充种性能。在此基础上,以排种合格率、单粒率、空穴率为指标进行了正交旋转组合试验,获得了最优工作参数组合。在排种轮转速、充种区高度以及毛刷/排种轮转速比分别为18 r/min、73 mm、2.5条件下,与现有凸齿式小麦排种器进行对比试验,交错勾齿式小麦排种器的排量变异系数比凸齿式排种器降低0.66个百分点,落种过程中排出的种子交错有序下落,具有更好的排种均匀性。

玉米精量播种机排种器关键部件延寿降本优化研究

为合理优化玉米精量播种机关键部件结构,延长机具使用寿命,降低维修成本,以排种器中关键部件支撑盘为研究对象,对其尺寸参数进行设计,通过有限元法分析其静力学特性、固有频率及振型特征。以支撑盘前两阶模态固有频率为指标,以支撑盘外边缘直径、支撑盘整体厚度、外边缘厚度为因素进行三因素三水平正交试验。最终分析得到优化后的最低固有频率为52.456 Hz,大于外界激励频率范围1~33 Hz,优化后的最大振幅由5.8473 mm降为3.6859 mm,有效避免共振干扰;试制样机进行台架疲劳试验,最终得到支撑盘的平均使用寿命为213 h,满足标准要求。为播种机的关键部件延寿降本优化提供理论参考。

Optimization design and experiment on ripple surface type pickup finger of precision maize seed metering device

A ripple surface type pickup finger was designed to improve the performance of pickup finger precision maize seed metering device and to provide a solution for precision maize planter.The main structure and working principle of seed metering device were detailed in this paper.The dimension size distributions of maize seeds in different types were studied,the gestures of seeds clamped by pickup finger were analyzed,and the clamping dynamical model of pickup finger was established by theoretical analysis.To optimize the structural parameters of ripple surface type pickup finger,the discrete element method(DEM)model of pickup finger precision maize seed metering device was established by the discrete element software EDEM.The numerical simulations of orthogonal seeding performance experiments were conducted to analyze the influences of these factors on the quality of seeding.The rotational speed,wavelength of ripple surface and amplitude of ripple surface were selected as the experimental factors.The average seeding qualified index and the average seeding coefficient of variation on four different types of maize seeds were chosen for evaluating the seeding performance.The results showed that,the average seeding qualified index was 93.35%and the average seeding coefficient of variation was 11.23%under conditions of the 25 r/min rotational speed,8 mm wavelength of ripple surface and 2 mm amplitude of ripple surface.Under the same condition,the bench test was done which showed that the results of test and simulation were consistent.The maximum error of qualified index was 1.95%and the qualified index of improved seed metering device exceeded the original one by 12.34%.The working performance can meet the requirements of precision maize seeding.

Design and experiment of the double-seed hole seeding precision seed metering device for peanuts

A secondary seeding precision double-seed peanut hole seeding seed metering device was designed to improve the performance of the peanut planting equipment and provide a solution for problems on the high seed charge that can cause poor cavitation and uniformity easily.The main structure and operation parameters in terms of groove length,seed charge height,seed-bed belt speed,and rotation speed of the seed metering wheel were determined through theoretical analysis.Single-factor and orthogonal tests were carried out through the JPS-12 seed metering device test bench,and the peanut variety Jinonghua-3 was selected as the test object.The single hole double-seed rate,qualified rate,the variation coefficient of hole spacing,and hole rate were chosen for evaluating the working performance.The results of the single-factor test showed that the seed metering performance is mainly affected by the groove length,the speed of the seed-bed belt and the rotation speed of the seed metering wheel,and the influence of the cavitation rate is minimal.The optimal seeding height is determined to be 40 mm.The results of the orthogonal test showed that the groove length was 27.3 mm,the seed-bed belt speed was 1.51 km/h,and the rotation speed of the seed metering wheel was 14.11 r/min.What’s more,a regression model based on the orthogonal test results was established,the qualified rate of the number of holes obtained after optimizing the model was 98.84%,the variation coefficient of hole spacing was 9.74%,and the hole rate was 1.40%.Notably,the working performances of the device can meet the requirement of precision seeding.

Design and Experiment of four Lines Trailed Potato Fertilization Seeder

In order to solve the problems which are widespread in potato seeding planter, such as lower operating efficiency, unideal performance index, higher replay rate and leakage rate and uneven spacing sowing in seeding operating, a trailed potato fertilization seeder was designed. The key components of the special structure had been got through the description of the structure and working principle of the whole machine. A crossing seed-taken technology along with the vibration component was adopted to achieve precision seeding. The results showed in the feld test of the machine： all the performance indexes of the machine met the agronomic requirement of potato planting; the multiple and missing index were low; it completed the ditching, fertilizing, seeding as well as ridging in one planting process; its operation effciency was high and the stability was good. This design of the trailed potato fertilization seeder provided a reference for the development of large traction-type potato seeding machine.

蔬菜气吸轮式精量排种器设计与试验

蔬菜类型多,种子尺寸差异大,为扩大排种器的适用范围,该研究提出一种基于扰种条辅助充种的蔬菜气吸轮式精量排种器。通过理论分析确定了排种器的关键结构参数,设计了一种带有坡度的扰种条结构,最薄处厚度为0.5 mm、最厚处厚度为1.0mm,并对充种阶段种子在扰种条上和清种阶段的受力情况分别进行分析,确定了扰种条和清种装置结构。选取菜心、萝卜和辣椒种子为试验对象,利用台架试验获得扰种条倾角和厚度的较优值;开展较优结构参数下的排种器充种性能试验,以工作负压、排种转速和清种距离为试验因素,进行三因素三水平正交试验。试验结果表明,对于菜心种子,工作负压为0.92 kPa,排种转速为13.3 r/min,清种距离为0.70 mm时,充种合格率为99.20%,漏吸率为0.13%;对于萝卜种子,工作负压为4.47 kPa,排种转速为25.5r/min,清种距离为1.20mm时,充种合格率为97.34%,漏吸率0.53%;对于辣椒种子,工作负压为1.49 kPa,排种转速为16.9 r/min,清种距离为0.69 mm时,充种合格率为88.27%,漏吸率为2.67%,满足菜心、萝卜、辣椒的种植农艺要求,研究结果可为蔬菜气吸轮式精量排种器设计提供参考。

气力离心组合式小麦精量排种器设计与试验

针对传统小麦播种以无序种流、不定量排出的方式存在脉动性高、均匀性差的问题,设计了一种气力离心组合式小麦精量排种器,采用气力充种和离心清种的方式,种子有序均匀排出。对排种器的关键参数进行设计,建立充种和排种过程的动力学模型,确定充种角和落种角的初始范围。利用气固耦合仿真分析方法DEM-CFD进行排种器单因素试验,仿真结果表明,当充种角范围进一步缩小为36°~56°时,其携种性能较好;落种角范围进一步缩小为43°~63°时,其排种性能较好。在此基础上,以充种角、落种角、排种盘转速为试验因素,以漏播率、重播率、直线落种率为响应指标,进行正交旋转组合试验。试验结果表明,当充种角为47.75°、落种角为52.48°、转速为635.5 r/min时,排种器工作性能最优,此时,漏播率为2.78%、重播率为3.73%、直线落种率为93.46%,验证试验结果与优化结果基本一致。田间试验结果表明,当设置排种盘型孔内侧面充种角为47.8°、下侧面落种角为52.5°、排种盘转速在552~800 r/min范围内时,漏播率低于8.9%、重播率低于4.3%、排种合格率高于88.6%,符合小麦精量播种要求。

气吸倾斜圆盘式蚕豆精密排种器设计与试验

针对蚕豆播种机械化程度低、精密播种效果差的问题,结合倾斜圆盘式排种器与气吸式排种器的优点,设计一种气吸倾斜圆盘式蚕豆精密排种器。首先,阐述排种器结构及原理,根据蚕豆的种植农艺要求及种子物理特性,对排种圆盘直径、型孔数量及形状等关键部件进行设计;然后,利用Fluent软件对不同形状气孔对气室流速及压力影响进行仿真分析,确定最佳的气孔形状;最后,以转速、型孔直径和气孔负压为试验因素,合格率、漏播率和重播率为试验指标,在JPS-12型视觉排种器性能试验台上进行正交试验。试验结果表明:当转速为78 r/min、气孔负压为2 kPa、型孔直径为23 mm时,排种试验合格率为93.67%,重播率为4.33%,漏播率为2%。