Parameter optimization and experiment of the negative pressure precision seed-metering device for wheat

In order to ensure the most reasonable distribution of wheat seeds in the field to improve seeding quality and uniformity,a set of negative pressure precision seed-metering device was designed,which shares a hollow shaft.Every seed-metering device can sow two rows of wheat.By the STAR-CCM+,the analysis of nephogram,vectogram and streamline graph showed that more ideal structural parameters of the seed-metering device are 0.5 mm width of the slit sucking seed(WSS),150-200 mm diameter of the seed-metering disc(DSD),2.0 mm axial depth of air chamber in the seed-metering disc(ADS),and arc-shaped cross-section shape of the ring groove sucking seed(CSGS).Single-factor test on the JPS-12 test-bed analyzed the influence of the CSGS,WSS,DSD,and ADS on the qualified index(Iq),multiple index(Imul),miss index(Imiss)and coefficient of variation of qualified seed spacing(CV).Through the orthogonal on the JPS-12 test-bed,it is found that the influence of vacuum negative pressure and seed-metering device shaft speed is significant on the Iq,Imiss and Imul.Based on these,the structural parameters of the seed-metering device were optimized.The DSD is 180 mm,the WSS is 0.7 mm,the ADS is 2.5 mm,and the CSGS is arc-shaped.The optimization seed-metering device was tested on the JPS-12 test-bed.The Iq is 86.66%,the Imiss is 5.09%,the Imul is 8.25%,and the CV is 24.50%.These testing results fully coincide with the standard JB/T 10293-2013 Specifications of single seed drill(precision drill).The seed-metering device meets fully the requirements for wheat precision seeding.

Optimized design of the pneumatic precision seed-metering device for carrots

The small size, light weight, irregular shape, and impurities that characterize seed groups increase clogging tendencies in the traditional seed-metering device thereby making it difficult to achieve high-speed precision seeding. A pneumatic seed-metering device with good seed-filling performance for carrot was designed in this study. By analyzing the movement state of seeds in the device under the theoretical condition, it was concluded that the minimum critical negative pressure value of air chamber was 0.32 kPa, which provided a theoretical basis for simulation and testing. ANSYS 17.0 Software was used to simulate the shape of the seeding plate hole. By comparing the pressure, air flow stability between the suction surface and the plug removal surface of the convection field, it was concluded that the conical hole was optimal. A bench verification test was conducted on the device. The average qualified rate, missing rate, and replaying rate were 81.48%, 4.07%, and 14.45%, respectively, which provided a strong reference for the design of carrot precision seed-metering device.

Seed guide path planning and parameter optimization for air-suction carrot seed-metering device

To meet the requirement of“zero speed”for precision sowing,the instantaneous speed of seed falling into the seed bed should be equal to the opposite direction of the forward speed of the machine.Through analyzing the principle of seed guiding process,the main influencing factors affecting the contour curve of the seed tube were determined to plan the seed guiding path and realize zero speed seed delivery.With the help of EDEM simulation software,taking the inclination angle of seed tube end,operating speed of the metering disc,and machine’s forward speed as the experimental factors,a single-factor simulation test was conducted with the pass rate,replay rate,and missing seeding rate as experimental indexes.The results of the simulation test showed that the range of inclination angle of the seed tube end was 23°-40°,the range of machine forward speed was 5-9 km/h,and the range of operating speed of the metering disc was 15-40 r/min.The quadratic orthogonal rotation combination test method was carried out using the bench test,and a mathematical regression model was established between experimental factors and experimental indexes to determine the priority order of factors,and the best combination of factors.The test results showed that the pass rate was 93.25%,the replay rate was 2.97%and the missing seeding rate was 3.78%under the condition with the inclination angle of seed tube end of 32.28°,the forward speed of the machine of 6.89 km/h and the operating speed of the metering disc of 28.67 r/min,which can meet the requirements of relevant national standards.

Design and experiment of conical diversion virus-free potato minituber precision seed-metering device

In order to accelerate the development of sowing mechanization of virus-free potato minituber,a conical diversion virus-free potato minituber precision seed-metering Device was designed according to the structural characteristics and agronomic requirements of virus-free potato minituber.The device is mainly composed of conical turntable,transmission shaft,outer baffle of seed-metering Device,baffle,seed outlet,seed cleaning device,type hole,etc.The working principle of conical diversion precision seed-metering device for virus-free potato minituber was expounded,and the stress analysis of virus-free potato minituber in each region was carried out.By EDEM discrete element simulation software,the structure of the type hole is optimized to determine the optimal structure of the type hole and according to the physical characteristics of virus-free potato minituber,the single factor experiments of the effects of length of type hole,cone disc speed and cone disc angle on seed filling performance were completed.The orthogonal regression test was carried out with the length of type hole,cone disc speed,and cone disc angle as the test objects,and the leakage rate and qualified rate as the response indexes.The regression models of leakage rate,replay rate,and qualified rate were established,and the parameters of the regression model were optimized.The optimal parameter combination is that the length of type hole is 33.61 mm,the cone disc speed is 6.35 r/min,and the cone disc angle is 26.59°.Bench test was carried out under the optimal conditions,the leakage rate was 3.80%,the replay rate was 0.80%,and the qualified rate was 95.40%,which was basically consistent with the prediction results of the regression model,and met the requirements of precision sowing of virus-free potato minituber.

烟草钵苗双盘对称交错式自动取苗装置设计与试验

为解决烟草半移栽作业用工量大、效益低等问题,设计一种对称交错式自动取苗装置。首先,阐述该自动取苗装置对两盘钵苗进行交错式取苗的原理,建立取投苗作业过程中的动力学和运动学模型。然后,对送盘装置、取投苗装置和自动控制系统等取苗装置关键部件进行结构设计,分析关键部件的作业过程,结合实际需求完成关键元器件的选型。最后,在已有移栽机动力底盘的基础上试制2ZY-1型烟草移栽机样机,以60天苗龄的烟草钵苗为作业对象进行田间取投苗性能试验。试验结果表明,在自动取投苗速度为20株/min时,取苗成功率为89.63%,投苗成功率为97.20%,伤苗率为3.59%。

烟苗移栽机用浇水装置的设计与试验

针对现有烟苗移栽机用浇水装置水资源利用率不高、浇水时会对幼苗和土壤造成强烈冲击以及不能够与移栽作业保持同步运行等问题,提出了一种新的烟苗移栽机用浇水装置。通过建立该装置的三维模型并对其中的倒水组件进行了理论研究和ADAMS仿真,得到了其运动特性及运动曲线图。首先,以时间作为试验指标,通过浇水组件对不同体积的水进行浇灌试验,测量所需的倒水时间和总时间,并对其进行一元线性回归拟合得到拟合方程;其次,采用相同体积的水,利用不同出水口口径的导流器进行浇灌试验并进行单因素方差分析。结果表明:导流器出水口口径的大小是影响浇水时间的重要因素,口径越大,导流速度越快,浇水所需时间越短。将装置设置于移栽机上,可与移栽作业保持同步。研究为移栽机用浇水装置提供了一种新的设计思路和理论依据。

烟草垄体分层施肥土壤镇压试验与肥料颗粒偏移分析

【目的】研究烟草起垄分层施肥镇压复合作业时,镇压压强P与土壤下陷量B的关系、土壤下陷量B与据表层150 mm处的土壤坚实度M的关系及土壤内部肥料颗粒的偏移情况,为镇压装置与分层施肥装置关键结构的设计提供理论基础。【方法】通过改变施加载荷的大小进行镇压试验,测量垄体表层土壤下陷量B和距离表层150 mm处的土壤坚实度M,获得P-B曲线和B-M曲线,根据烟草移栽农艺要求确定土壤下陷量B和压强P的范围。通过EDEM仿真,得到土壤镇压作业时内部颗粒的偏移情况。【结果】得到了在符合作物生长需求的条件下,镇压产生的土壤下陷量B的范围为5~33 mm,相应施加在土壤表面的压强P为5~23 kPa;在土壤下陷量B为25 mm时,分层施肥肥料颗粒向下偏移量分别为20.2、15.1、7.7、4.8 mm,与镇压试验结果误差为10.0%~14.6%。最后通过田间试验进行验证。【结论】根据土壤压缩及内部颗粒偏移规律设计分层施肥镇压装置,垄内分层施肥深度稳定,整形效果良好,可为镇压装置及垄内分层施肥装置的设计提供参考。

密集烤房倾斜夹取式装烟机设计与试验

针对密集烤房装烟劳动强度大、装烟效率低、装烟设备不适用等问题,基于密集烤房及烟竿的结构特点,设计一种倾斜夹取式装烟机,主要由动力平台、升降装置、夹取装置组成。提出一种由夹取机构和倾斜机构组成的烟竿夹取装置,阐述其工作原理,对倾斜过程进行运动学分析。设计一种由提升机构和举升机构组成的升降装置,分析门架系统的受力情况,并利用ANSYS Workbench软件对门架系统进行有限元分析。在密集烤房内进行装烟试验,并分别设置人工和举升式装烟机装烟两组对照试验。结果表明,倾斜夹取式装烟机能够满足密集烤房装烟要求,平均装烟成功率为96.7%,平均烟竿偏移率为4.8%,平均装烟速率是人工装烟的4.1倍,从而验证该倾斜夹取式装烟机理论分析与设计的准确性及合理性。

Design and parameter optimization of air-suction wheel type of seedmetering device with elastic pad for maize

Due to the maize growing agronomy requires ground covered by mulch film in the arid zones of the China Northwest region,the seed-metering device must roll over,break the film,and then throw seeds into soil.However,the uneven ground can cause the seed-metering device to shake,reducing seed-metering performance.To improve the adaptability for different shapes of maize seeds,a air suction wheel type seed-metering device with elastic pad was developed for better seed extraction and bump resistance.Firstly,the advantages and influencing factors of the elastic pad were analyzed through four processes of metering seeds.Secondly,the velocity distributions of six diameters of the suction hole are compared to determine the range with FLUENT.Then,a one-factor experiment was conducted to analyze the pattern of the factors(the seed layer height,the critical vacuum,the rotational speed of the seed disk,and the suction hole diameter)influencing the metering seed performance.Finally,a five-level quadratic rotation orthogonal design was used to optimize the parameters.Results show that the optimal values are that the seed layer height is 40 mm,and the critical vacuum is 2.85 kPa,and the rotational speed of the seed disk is 20.1 r/min.The validation experiment resulted in a 93.79%qualified index,with a 4.02%missing index and a 2.19%multiple index.

丘陵山区电动井窖式烟草移栽机设计与试验

结合烟草小苗移栽农艺要求,设计了一种适用于丘陵山区的电动井窖式烟草移栽机,整机具备机械化井窖成穴、投苗和浇水等小苗移栽作业功能。在完成移栽机挖穴装置、投苗装置和浇水装置等关键零部件模块化设计和组装后进行田间试验。试验结果表明,井窖式烟草移栽机作业效率0.402 hm2/d,井窖成穴合格率>90.8%,移栽作业合格率>87.7%,满足丘陵山区烟草井窖式移栽作业要求,为丘陵山区烟草小苗井窖式移栽技术的推广应用提供装备支撑。

贮丝柜底带密封装置的研制与应用

在卷烟工厂中,贮丝柜在制丝线上主要负责物料贮存、缓冲上下游生产、平衡物料水分及温度、促进物料的香糖料吸收,在工艺保障及平衡生产方面起到了重要的作用。但在实际应用中,贮丝柜底带弧形密封处容易漏出烟丝的问题成为其顽疾,不仅造成物料浪费,且影响车间现场规范管理。所研制的贮丝柜底带密封装置并投入使用,巧妙解决了弧形密封容易漏烟的问题。

烟草生产线中智能设备的集成与自动化控制研究

基于先进技术的应用基础,分析了目前烟草生产线所面临的智能化需求,明确指出烟草生产线中智能设备集成必要性。在此基础上,构建了烟草生产设备管理系统架构,详细阐述了烟草生产线智能设备集成关键技术,具体涉及信息采集、设备检查管理、高速自动化机械技术等的应用。同时,设计自动化控制业务模块,覆盖原料处理配送、烟叶加工切割、制丝烘干等多个模块,皆在实现对整个烟草生产线的智能化管理。

叶片复烤机进料层厚度检测装置的研发

烟叶复烤加工是烟叶加工过程中的重要环节,而叶片复烤机则是其中的主要设备。叶片复烤机通常由刮板喂料机、仓式喂料机、进料端口、干燥段、冷却段、回潮段、出料端及管路系统等组成。以对流传热方式干燥物料,在干燥过程中,物料的干燥速度与网面物料厚度呈负相关。在循环空气流速、温湿度一定的条件下,物料的铺层厚度较薄时,干燥效果较好。因此,进料层厚度的控制对加工质量具有一定的重要性。针对叶片复烤机进料层厚度检测装置开展研究,设计一种新型的厚度检测装置,以期进一步提高烟叶加工质量和效率。

YN30型残废烟支烟丝回收装置的设计与应用

针对传统残废烟支烟丝回收装置存在的烟丝回收率低、纯净度差、整丝率偏低、细支卷烟加工适应性差等问题,研制一种新型残废烟支烟丝回收装置。该装置通过滚筒筛网和搓丝螺杆机构实现了烟丝与卷烟材料的快速分离,通过静电吸附和负压剔除相结合的除杂技术,实现了分离烟丝精选除杂。以常规卷烟牌号云烟(紫)以及细支卷烟牌号云烟(细支珍品)进行应用测试,常规卷烟加工回收烟丝得率≥80.0%,细支卷烟加工回收烟丝得率≥70.0%;回收烟丝纯净度≥99.0%;回收烟丝整丝率≥60.0%;回收烟丝碎丝率≤6.0%;处理前后烟丝含水率变化≤0.5%。该装置同时可以满足常规卷烟和细支卷烟的残废烟支回收。

烟草高架仓库多设备耦合火灾预警试验研究

通过缩尺寸模型试验研究烟草高架仓库顶棚、端墙、侧墙和货架及货物等形成的特殊遮挡结构微元对火灾早期烟气蔓延规律的影响,结合不同火源位置条件下火灾探测器预警情况,提出6种火灾自动报警系统耦合方案并分析报警有效性。结果表明:火源位于底层时烟气在竖向蔓延过程中紧贴货架及货物侧面,撞击端墙后形成反浮力壁面射流;火源位于顶层时,特殊遮挡结构微元的空腔成为储烟区域,火灾早期未出现反浮力壁面射流。线型感温与吸气式感烟火灾探测器组成的火灾自动报警组合,报警响应时间较短,环境敏感性较低,报警有效性较高。线型感温和图像型火灾探测器组成的报警组合存在探测盲区,环境敏感性高,报警有效性较低。

存储筒除烟末系统改进设计及应用

YF17,YF17A卷烟储存输送装置在清洁过程中会有大量烟末从设备缝隙进入存储筒内部。并且由于机械结构限制,需拆卸存储筒才能进行有效清洁。烟末的长期存在会滋生烟虫,从而严重影响烟支质量。针对此问题,该文提出存储筒除烟末系统改进方案,通过对YF17,YF17A卷烟储存输送装置存储筒传动结构的分析,设计一套存储筒清除烟末的系统,以防止烟末进入存储筒内部,同时将进入存储筒的烟末自动清扫出存储筒。YF17,YF17A卷烟储存输送装置存储筒经过为期300天的验证,实现了存储筒清除烟末的功能,有效预防了烟虫的滋生,提高了烟支质量,此改进方法对存储筒结构改进有重要参考意义。

Design and test of an inside-filling pneumatic precision centralized seed-metering device for rapeseed

The pneumatic precision seed-metering devices used in combination with negative air pressure to suck seed and positive air flow to drop seed could overcome the problem of rapeseed precision planting.However,these devices can only plant a single row at a time or need high airflow pressure,which complicates the seed-metering system and the seeder structure,deteriorate the working reliability and have high power consumption.To overcome above shortcomings,a novel prototype of pneumatic precision centralized seed-metering device with seed inside-filling,sowing six rows at a time,was developed.The main structure and working principle of the prototype were described and the technical parameters were given.Experiments were conducted to investigate the influences of positive pressure,negative pressure,and rotating speed on the seeding performance.The stability of each row and the consistency between all rows associated with the seeding precision were analyzed to evaluate the performance of the prototype.The results indicated that the prototype can meet the requirements of precision seeding and the seed keep intact without any obvious damage.The performance of the prototype was no significant difference when the positive pressure was fluctuated from 200 Pa to 1200 Pa.The best seeding precision parameters in one row of the prototype was 92.48%of the qualified seeding index(Iqs)and 2.55%of the miss-seeding index(Imiss),when the rotating speed was 16 r/min,the positive pressure was 200 Pa and the negative pressure was–1600 Pa.When the rotating speed was 16 r/min,the positive pressure was 200 Pa,and the negative pressure was–1400 Pa or–1600 Pa,the Iqs of six rows were above 86.5%,the stability coefficient of variation(CV)of each row were below 4.6%,and the consistency CV were below 0.9%.Further field experiment showed that the rapeseed sowed by the prototype had acceptable seeding precision.The CV of the numbers of rapeseed seedlings in the field of the total and each row were 6.17%and 6.32%respectively.The research confirmed that the inside-filling pneumatic precision centralized seed-metering device satisfied the agronomic requirements of rapeseed planting and can be a reference for the development of precision seed metering devices.

Design and experimental study of the control system for precision seed-metering device

The precision seeding technique has been developed at full speed along with the continuous development of new agricultural technologies,especially those concerning cultivated patterns.The seed-metering device is the key component of a precision seeder.A ground wheel is used to drive the seed-metering device of the conventional direct seeder.However,the wheel bears high resistance and easily slips.Moreover,the adjustment of the precision seeder’s seeding rate is more difficult.In order to solve these problems,a control system which could keep the rotational speed of the seed-metering device consistent with the seeder’s working speed for the precision seed-metering device was designed.The control system includes a Hall sensor,a single chip microcomputer system,a motor control module,a stepper motor and a display.The control system used a Hall sensor to measure the seeder’s working speed and employed a single chip microcomputer system to predict the rotational speed of seed-metering device.It would then determine the relationship between the seeder’s working speed and the rotational speed of the seed metering-device according to the seeder’s working state,distance between seeds and the requirement of sowing rate.The system could effectively reduce the influence of inhomogeneous sowing caused by the ground wheel’s slipping.The system was found to be reliable by the experiment.The seeding control system could also make the speed of the seed-metering device and seeder’s uniform,improving the uniformity of the amount of seeding,and achieving the goal of design.This new design provides a platform to solve problems of the seed-metering device and the seeder.

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.

Design and experiment of a six-row air-blowing centralized precision seed-metering device for Panax notoginseng

Panax notoginseng is grown mainly in Yunnan Province.Under the present high-density planting patterns for the plant,to solve the problems of a high rate of seed damage and the inability to use a traditional single air-blowing metering device,this paper designs a six-row air-blowing centralized precision seed-metering device for P.notoginseng to realize mechanized precision seeding of this species.This paper describes the working principle of the seed-metering device,and the main structural parameters are determined by combining theoretical calculations with simulation analysis.A mechanics model of the seed filling,cleaning and pressing processes of the seed-metering device was constructed.The seeds of P.notoginseng in Yunnan Province were selected as experimental subjects.An experimental study on the seed-metering performance of the seed-metering device was carried out using the quadratic rotation orthogonal combination test method.The outlet pressure of the air nozzle,forward velocity and cone angle of the hole were selected as test factors.Mathematical models of the grain spacing qualified index,miss index,multiple index and the coefficient of variation of the row displacement consistency were established to analyze the order of factors affecting indicators.Through parameter optimization,the optimum combination of parameters was determined as follows:the cone angle of the hole is 50°,the forward velocity is less than 0.73 m/s,and the outlet pressure of the air nozzle is 0.32-0.52 kPa.The qualified index of grain spacing is higher than 94%,the miss index is less than 3%,the multiple index is less than 5%,and the coefficient of variation of the row displacement consistency is less than 5%.The test results are essentially consistent with the optimization results.The metering device meets the requirements of precision seeding of P.notoginseng.This study provides a basis for the design of a six-row air-blowing centralized precision seed-metering device for P.notoginseng.