共查询到19条相似文献,搜索用时 218 毫秒
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水稻精量穴直播排种器的设计 总被引:1,自引:0,他引:1
根据水稻精量穴直播的农艺要求,确定了以型孔式排种器作为水稻精量穴直播机的排种器。根据稻种在重力场中的运动状态选定了瓢形型孔等5种型孔形式进行试验研究。通过对各种清种方式的分析,决定采用轮式清种机构,提出了护种板和强制排种机构的形式。 相似文献
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为满足机械式精密排种器高速作业的要求,以增加充填力的方式对立式圆盘排种器进行改进,设计了一种利用重力与离心力以及种子间相互作用力作为复合力进行充种的双腔立式浅盆型复合种盘机械式精密排种器,并对排种盘的特征参数进行了优化。利用离散元仿真分析软件EDEM对立式浅盆型种盘进行了以排种盘直径、折边倾角、作业速度为影响因素,充填率为性能指标的三因素五水平二次正交旋转组合仿真设计,并运用Design-expert 8.0软件对数据进行了处理,获得了排种盘最优的结构参数组合,同时利用物理样机试验进行了验证。研究结果表明:立式浅盆型种盘的最佳结构参数组合为排种盘直径234mm、折边倾角68°,在8 ~12km/h高速作业时,合格率均能达到90%以上。研究结果为产品定型提供了定量的依据。 相似文献
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小型穴播机的试制研究 总被引:1,自引:0,他引:1
机械精密播种技术是一项科技含量高、节约成本、增加效率的适用技术,是保护性耕作的重要内容之一[1]。穴播是实现精密播种的主要技术,其中穴播器是实现穴播技术的关键部件,穴播机械也逐渐成为播种机械的重要组成部分。穴播机主要由排种器和穴播器两个核心部件组成,排种器的主要功能是根据播种需要均匀取种并排到穴播器当中;穴播器 相似文献
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1 小麦常量、少量播种机械化技术
小麦常量、少量播种机械化技术也称小麦精少量播种机械化技术。这种技术目前在国内使用较为广泛,即选择适宜的播种机按照农艺要求将一定数量的种子播入土壤的技术。该技术以使用外槽轮式排种器的谷物播种机为特征。常量播种技术所使用的播种机,常使用小槽轮排种器。播种麦类作物排种均匀性较好,适于播量较大的小麦播种;少量播种技术所用的播种机,常使用斜外槽轮、细外槽轮、螺旋细外槽轮等排种器,这些排种器的均匀性优于小槽轮排种器,适于播量较小的麦类播种。 相似文献
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气吸式精量播种机是当前国内外普遍采用的精量播种机械,其常见故障主要有以下几种. 1.排种量不稳定 (1)排种量不稳定的原因①吸气管路有破损,如漏洞、接头连接松动、裂纹等使气压下降,气吸力减小,种子没吸住致使一部分或全部漏播. 相似文献
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手提式玉米播种机是目前应用比较广泛的播种设备,而排种装置则是手提式播种机控制播种精度的重要部件。对排种装置进行了详细的设计,具有单籽、双籽、三籽可控的排种装置设计特点,通过实验数据优化了排种轮型孔的尺寸,有效地解决了卡籽漏籽的现象。 相似文献
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阐述电伺服拉床的机电一体化系统结构,介绍拉床工作台的双伺服同步驱动系统及双滚珠丝杠机械传动机构。为提高拉削过程负载断续变化时主溜板同步运行的精度,从提高单轴伺服系统本身抑制负载扰动性能的角度出发,设计基于扰动辨识和补偿机理的自校正算法,重点分析其原理。基于该自校正算法设计并实现了双轴同步驱动的控制策略,该控制策略具有简单可靠易实现的特点。以一台20 t的伺服拉床为研究对象,分别在两主溜板耦合和不耦合且受力不平衡的情况下对控制策略的同步性能进行了多种吨位的加工测试,试验结果显示该扰动补偿算法是有效的,基于该扰动算法的同步控制策略具有很好的同步精度,这给双滚珠丝杠伺服同步控制系统的应用提供了很好的理论参考和试验数据。 相似文献
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精密排种器的集成分析设计系统开发研究 总被引:10,自引:0,他引:10
采用离散元法研究了散粒物料之间、散粒物料与农业机械工作部件之间的相互作用以及散粒物料的流动过程,提出了由农业机械工作部件计算机辅助设计模型建立其离散元法分析模型的方法。在此基础上实现了计算机辅助设计软件与离散元法性能分析软件的集成,由此开发出了一种播种机精密排种器的集成分析设计系统。介绍了精密排种器离散元法分析模型的建立、种子的生成、邻居搜索与接触判定、数据传递及软件集成方法。最后,通过实例验证了系统的可行性。 相似文献
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《Measurement》2014
Wheat product quality is closely related to wheat seed purity. Purity is an important factor that has a considerable impact on wheat product prices in grain storage silos. The aim of this paper was to introduce a machine vision based approach as a primarily step for fabricating an automatic wheat purity determination and grading device. Experimental data consists of 52 color, morphology, and texture characteristic parameters, extracted from images of samples, including four local wheat grades and eight common weed seeds growing in wheat fields of Iran, were used to build the classification models. A new algorithm that combines Imperialist Competitive Algorithm (ICA) and Artificial Neural Networks (ANNs) has been used for two purposes: to find the best characteristic parameters set and to create robust classification models. Based upon the results obtained from this study, the total classification rate of ICA–ANN approach for wheat grains vs. non-wheat seeds, wheat grain classes, and non-wheat seed classes was 96.25%, 87.50%, and 77.22%, respectively. 相似文献
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针对微结构聚合物元器件的批量化生产与制造效率低等问题,采用精密修整成V形尖端的金刚石砂轮,在自润滑性和脱模性良好的钛硅碳陶瓷模芯表面加工制造出形状精度可控的V沟槽阵列结构,然后利用微注塑成形工艺将模芯表面的V沟槽阵列结构一次成形复制到聚合物表面,高效注塑成形制造出倒V形阵列结构的聚合物工件。分析了微模芯的表面加工质量与形状精度,研究了熔体温度、注射速度、保压压力、保压时间等微注塑成形工艺参数对微结构聚合物注塑成形角度偏差和填充率的影响。实验结果表明:通过微细磨削加工技术和微注塑成形工艺可以高效率、高精度地制造出规则整齐的微结构注塑工件,注射速度对微成形角度偏差的影响最大,保压压力对微成形填充率的影响最大,微结构模芯的微细磨削形状精度值为4.05 μm,微成形的最小角度偏差和最大填充率分别为1.47°和99.30%。 相似文献
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Yan Han Wang Xian-kui Duan Guang-hong 《Frontiers of Mechanical Engineering in China》2006,1(3):260-264
The model of a precision linear motor drive device (PLMDD) and its control requirements are analyzed. In order to enhance
the tracking and anti-disturbance performance of the system, its third-order model is established, and disturbance-observer
based input revising feedforward error compensation robust control algorithm, combined with integral-separated proportional
integral derivative (PID) control algorithm is proposed. This includes feedback control algorithm and feedforward control
algorithm. The feedback controller improves system tracking performance and suppresses load and mechanical disturbance while
the feedforward controller compensates phase hysteresis introduced by feedback control. Theoretical analyses, simulations
and experiments show that this control method increases the tracking precision of PLMDD from ±5 μm to ±2 μm and dramatically
improves its anti-disturbance ability. 相似文献
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Sumreen Dawood Mushtaq Ahmad Muhammad Zafar Muhammad I. Ali Khalid Ahmad Shazia Sultana Anwer Usma Moona Nazish Maryam A. Butt Fethi A. Ozdemir Omer Kilic 《Microscopy research and technique》2020,83(2):165-175
Exploration of substitute energy feed‐stocks is the much‐debated topic in the scientific society due to increasing power crises and related ecological concerns. As a source of sustainable energy, biodiesel turns out to be the best alternative to petro fuels. In this context, nonedible oil‐producing seeds might be a potential source for biodiesel production owing to their environment‐friendly nature and cost‐effectiveness. The current study, consequently, deals with the investigation and identification of micro‐morphological characters between six novel nonedible oil‐bearing seeds employing scanning electron microscopy as possible biodiesel feed‐stocks. Light microscopic examinations show that seed size varies from 0.3 to 1.3 cm in width and 0.5 to 1.5 cm in. Additionally, a large difference in seed color ranges from dark brown, black, and various shades of light brown was also witnessed. The FFA content of the seeds ranges in 0.3–4.1 mg KOH/g, and the seed oil content fall in 30–65% (w/w) range. SEM‐mediated seed ultrastructure investigations displays greater variation in seed size, shape, color, periclinal wall shape, and sculpturing and so on. All the seeds differ from rounded, ovoid, ovate, oblong, flattened, and elliptical shape. Greater variation in seed wall structure has been seen from angular, entire, irregular, straight, elongated, smooth, and polygonal. The periclinal wall arrangements show alteration from flat, depressed, elevated, smooth, pentagonal, bullate, and coarse seed margins. The results obtained from the current study suggest that scanning electron microscopy could be a beneficial tool in vitalizing the hidden micromorphological characters among various nonedible oil producing seeds, which eventually helps in exploration, correct identification, seed classification, and authentication in future. 相似文献
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研究了具有"双材料梁-微镜一体化"特征结构的光读出红外成像阵列器件的机械特性对其性能的影响。通过理论计算和ANSYS模拟,分析了器件的热-机械灵敏度,对器件的结构参数进行了优化,并得到其热-机械灵敏度为2.14×10-3 rad/K;从器件的频率和阻尼特性出发,研究了器件的机械特性对热振动噪声和机械稳定性能的影响。研究结果表明:绝热梁断裂所需冲击载荷为8 945 g;器件的工作气压确定在50~200 Pa时,其热机械噪声和外界机械振动引起的噪声对器件性能的影响可忽略。该器件基本满足红外成像阵列器件的高灵敏度、低噪声的要求。 相似文献