粉状危化品计量系统的加料方式

目的 以粉状危化品计量系统中的加料方式为研究对象，研究一种流动性差的危化品物料的加料方式。方法 从安全性角度分析现有强制性螺旋加料和振动加料不适合粉状危化品加料的原因；根据慢加料原理，提出激励加料方式，构建其工作原理和结构，并通过控制振动源启停和振动频率，以及加料门的开合角度来实现快慢均匀加料；采用离散元仿真软件对慢加料过程进行仿真，分析物料连续均匀下落所需的振动力，得到加料流量与振动频率、振幅和出料口尺寸的关系。结果 激励加料方式适合于粉状危化品加料，能满足其加料要求。结论 基于上述结论，设计和制造了加料设备，试验结果表明，该装置完全满足计量系统中快慢加料的要求，对同类型的物料加料具有一定的指导意义。     

基于模糊PID的螺旋加料机构粉体进料精度控制

目的 螺旋式加料机构存在传感器响应时间差，造成系统延迟，非线性等问题，采用容积式来计量填充物料的质量的填充误差大。本文提出一种基于模糊PID控制的螺旋式加料机构计量控制系统。方法 利用模糊PID对螺杆式粉料加料装置进行控制，通过模糊规则对PID控制比例、积分、微分参数实现参数自调整。基于Matlab中Simulink模块下模拟该模糊PID控制系统。结果 该控制系统稳定时间减少了66%，快速性提高了21%，超调量降低了10%。结论 基于模糊PID控制系统的计量控制性能优于传统PID的。     

黑索今粉料安全、连续加料与计量装置

为了解决黑索今粉料因流动性差而容易在料斗卸料口结拱,造成卸料口堵塞,使黑索今粉料连续化、自动化加料中断,影响计量精确性和安全性的问题,设计一种黑索今粉料安全、连续加料计量装置,利用粉体流动测试仪测试黑索今粉料的流动性参数。结果表明:该装置的合适料仓参数为料仓半顶角小于28.9°,料仓出料口直径大于168 mm;在利用该装置加料的过程中,黑索今粉料能均匀、稳定地从料仓流出,计量误差小于1.0%。     

一种“按后不管”理念的全功能自动液体灌装机

灌装机是一种用途非常广泛的称重测控系统。通常的做法是利用一个或两个球阀控制物料加料速度．在预先设定的关断点关闭加料阀门以达到定量灌装的目的。     

重力称重式充填机三段式加料系统原理的研究

从重力称重式充填机加料方式的角度探讨其对充填精度与速度的影响机理,分析了常见重力充填机的工作原理与存在问题,提出了三段式加料系统原理,着重阐述了加料斗加料和变速快加料的实施方法.     

混合式定量加料过程的PID-模糊控制

在论述混合式定量加料原理的基础上，介绍了PID-模糊控制在混合式定量加料中的应用，研究了一个具体的PID-模糊控制设计方法，在实验的基础上得出相关的参数，用Matlab仿真结果表明PID-模糊控制提高了称重过程加料精度，并有效地改善控制系统的稳定性和可控性。     

扁平式气流磨制备超细粉料的研究

对I0型扁平式气流磨粉碎性能进行了研究 ,以α Al2 O3 为粉碎物料 ,探讨了加料速度、工质压强对粉碎效果的影响 ,并优化了气流磨的工艺操作条件 ,在最优工况下确定极限粒径     

螺旋式定量包装秤的研究

运用称重定量包装的基本理论，结合小型定量包装秤的实际应用，提出了一种针对散体物料以螺旋为加料方式的新型定量包装秤的构思。对其中的构造和工作原理、结构和工艺参数及其技术性能作了比较全面深入的理论研究和探讨。获得了在一定范围内同时提高小型定量包装秤定量精度和速度的可行结构、相关措施和理论结果。     

硝基胍喷雾干燥过程连续计量加料技术

在硝基胍（NQ）喷雾干燥加料过程中,为实现连续、安全、均匀、稳定地计量加料,对NQ喷雾干燥加料系统开展在线浓度、流量与干量计量检测的试验研究。采集不同浓度下的NQ浆料与纯NQ光谱,对比不同预处理方法的优化效果,采用偏最小二乘法选择特征区域建立加料浓度模型,并对模型进行重复性验证。选择一阶导数加标准正态变量变换方法对原始光谱进行预处理,在6 857~6 426 cm^-1     

叶片加料机加水功能改造

本文详细分析叶片加料机加料出料含水率波动这一问题的发生原因,应用现场调查和试验的方法来探寻叶片加料自动补水系统的研制方法,确保叶片加料后出料叶片含水率均匀稳定,消除含水率低点,提高叶片的含水率,满足后续生产工艺要求,保证了烟丝内在质量的稳定性。     

The forces exerted by aquatic suction feeders on their prey

Successful prey capture by aquatic suction feeders depends on the ability of the predator to generate a flow of water external to the mouth that overcomes any movements and forces that the prey uses to resist the suction flow. Elucidating the nature and magnitude of these forces is a key to understanding what limits suction feeding performance. We identify three potential forces produced by the suction flow field: drag, acceleration reaction and the fluid pressure gradient. Using a mathematical model parametrized with empirical data from feeding bluegill, Lepomis macrochirus, we explore the relative magnitude of these forces under three encounter scenarios with a 5mm diameter, spherical prey: an immobile mid-water prey; a similar prey that executes an escape response; and a prey item that grips a substratum. Contrary to the almost exclusive emphasis on drag in the suction feeding literature, it made a minor contribution to the total forces in all three cases. In all three scenarios, the pressure gradient is the largest of the three forces. These results are important because previous researchers have emphasized drag and have not explicitly recognized a role for the pressure gradient force in suction feeding. The simulations suggest previously unrecognized mechanisms that suction feeders can use to enhance the forces that they exert, by increasing the steepness of the pressure gradient that the prey item is exposed to. This can be accomplished either by increasing the rate of increase in fluid velocity or by restricting the size of the mouth aperture, which creates a steeper spatial gradient in pressure.     

间歇式立式包装机的补偿方式

在立式自动包装机上的机械式材料供送中，一般都用超前补偿。提出一种使一般的补偿机构能实现随机补偿的机理。     

海带条自动上料机的设计及应用

目前对于形状和尺寸均确定的刚体的自动上料已有成熟技术,但对于柔性物体的自动上料尚没有完善的解决方案,针对具有高度柔性的海带条设计了海带条自动上料机.该机采用PLC控制、步进电机驱动,包括绕水平轴间歇回转180°的转台和在转台上对称布置的2对用于夹持海带条的专用夹具.通过对海带条相对尼龙的摩擦系数、海带条在自重作用下弯曲与伸出长度关系的规律、海带条强度等实验得到了海带条的基本物理力学性能,设计并制造出对厚度范围在0.5～1.5 mm的海带条有足够夹持力且同时可以顺利被拉出的专用夹具,完成海带条自动上料机的机械系统及控制系统的设计.通过对该机的试运行,证明研制的海带条自动上料机满足了海带打结机自动上料的要求.     

Anterior-to-posterior wave of buccal expansion in suction feeding fishes is critical for optimizing fluid flow velocity profile

In fishes that employ suction feeding, coordinating the timing of peak flow velocity with mouth opening is likely to be an important feature of prey capture success because this will allow the highest forces to be exerted on prey items when the jaws are fully extended and the flow field is at its largest. Although it has long been known that kinematics of buccal expansion in feeding fishes are characterized by an anterior-to-posterior wave of expansion, this pattern has not been incorporated in most previous computational models of suction feeding. As a consequence, these models have failed to correctly predict the timing of peak flow velocity, which according to the currently available empirical data should occur around the time of peak gape. In this study, we use a simple fluid dynamic model to demonstrate that the inclusion of an anterior-to-posterior wave of buccal expansion can correctly reproduce the empirically determined flow velocity profile, although only under very constrained conditions, whereas models that do not allow this wave of expansion inevitably predict peak velocity earlier in the strike, when the gape is less than half of its maximum. The conditions that are required to produce a realistic velocity profile are as follows: (i) a relatively long time lag between mouth opening and expansion of the more posterior parts of the mouth, (ii) a short anterior portion of the mouth relative to more posterior sections, and (iii) a pattern of movement that begins slowly and then rapidly accelerates. Greater maximum velocities were generated in simulations without the anterior-to-posterior wave of expansion, suggesting a trade-off between maximizing fluid speed and coordination of peak fluid speed with peak gape.     

纸张在弹性胶辊夹持下接触区域的数值分析

在准静态、无摩擦的条件下,应用级数形式的应力函数对复印机中纸张在弹性胶辊夹持下的接触问题进行了分析。模型源于复印机中的进纸单元,根据弹性理论,分别使用施密特正交化方法与无网格配点法对问题进行了求解,得到了接触区域的应力应变分布以及胶辊与纸张的表面速度比,为提高复印机胶辊的可靠性提供了参考。     

钎焊环定量称重系统的飞料自校正补偿方法的研究

通过对称重系统下料系统方案的设计,采用粗、中、细3级给料的方式,以尽可能减少给料控制过程中,飞料对系统最终称量精度产生的影响。在中给料环节,采用自校正算法对提前量进行实时的校正,使实际计量值和设定值接近,进一步减小飞料对系统精度的影响,保证细给料环节有一个较小的给料量,解决了系统的称重精度和速度之间的矛盾。     

Piezo actuated vibratory feeding with vibration control

This research investigated the effect of decoupling the motion of a conventional vibratory feeder in order to develop a one-axis vibratory sliding mode for feeding tiny delicate parts that could ultimately be adapted to two axes. This research investigated a new type of vibratory drive by employing a piezoelectric actuator. In a decoupled design, the action of the horizontal and vertical vibration would be separately controlled to achieve a desired part trajectory and consequently the feed rate of the part. A computer control scheme was used to develop voltage input waveforms to control these actuators to produce movements that cause the parts to move forward relative to the track and overcome backsliding and other inefficient feeding motions. There are two advantages to this type of design. First, it can handle the parts in a more controlled manner by keeping them in constant contact with the track while maintaining a high conveying speed. This results in good protection for fragile parts. Secondly, this concept results in feedback control schemes that could allow the computer to adjust the drive waveforms to optimize feeder performance. Due to the non-sinusoidal nature of driving waveforms, the higher harmonic components can excite undesired deformation of the responding trajectory. A self-tuning control based on dynamic system identification was employed to counteract the higher harmonic effect. A one-dimensional hardware model is built and experiments were conducted to verify the precision and feasibility of the controlled actuation.     

油墨回流对供墨调节的影响

输出墨量的正确控制是影响印刷质量的最重要因素之一.分析油墨转移过程中,输出墨量、回流墨量和消耗墨量之间的关系,提出了输出墨量并不等于承印物消耗的墨量,墨键开度的设置不应该正比例于版面覆盖率分布,橡皮布的油墨传递率的变化需要等量地增减输出墨量来适应.     

基于TRIZ理论的成垛浆粕上料机设计

目的针对目前成垛浆粕上料采用人工操作产生的劳动强度大、效率低、人力成本高的问题,设计一种成垛浆粕自动上料机。方法运用TRIZ理论的冲突解决原理进行成垛浆粕自动上料机设计,设计中对存在的问题进行归纳和分析,根据自动上料机的冲突矩阵,得到相应的创新设计原理,通过分析比较选择最佳原理解决设计中涉及到的技术冲突问题,并利用有限元软件对滑套进行力学分析。结果基于TRIZ理论设计的自动上料机可实现自动寻料、自动夹紧、自动提升、自动旋转、自动放料。结论该上料机完全取代了人工操作,生产效率提高了38%。