基于PLC控制的全自动免熔铅制粒机的研究

目前国内铅酸电池行业多用岛津法生产铅粉,需将电解铅铸造成铅球或铅段,再利用球磨机磨碎成铅粉,由于受铅粒铸造工艺的影响,致使整个生产铅粉流程高污染、高能耗。对此,全自动免熔铅制粒机的开发势在必行。主要介绍了全自动免熔铅制粒机的机械原理、控制原理、主要设备及功能。该全自动免熔铅制粒机已经通过企业使用证明,能在冷态工作状态下将铅锭转化成大小均等的铅粒,并且集聚性能稳定、操作简单、节能环保、大大提高生产效率等优点。     

Utilizing the Explicit Finite Element Method for Studying Granular Flows

Granular flows are systems of complex dry particulates whose behavior is difficult to predict during sliding contact. Existing computational tools used to simulate granular flows are particle dynamics, cellular automata (CA), and continuum modeling. In the present investigation, another numerical tool—the explicit finite element method (FEM)—is analyzed as a potential technique for simulating granular flow. For this purpose, explicit dynamic finite element models of parallel shear cells were developed. These models contained 52 particles and consisted of granules that are both round and multi-shaped (diamond, triangle, and rectangle). Each parallel shear cell consisted of a smooth stationary top wall and a rough bottom surface that was given a prescribed velocity of U = 0.7 in/sec (1.78 cm/s). The coefficient of friction (COF) between the particle–particle and particle–wall collisions was varied between 0.0 and 0.75. Utilizing the output of the simulations, results are presented for the shear behavior, particle kinetic energy, and particle stresses within the shear cell as a function of time. As a means of validating the explicit technique for granular flow, a 75 particle, zero roughness, couette shear cell model (solid fraction of 0.50) is subsequently presented for which direct comparisons are made to the results published by Lun. [Lun, C.K. et al.: Phys. Fluids 8, 2868–2883 (1996)] Overall, the results indicate that the explicit FEM is a powerful tool for simulating granular flow phenomena in sliding contacts. In fact, the explicit method demonstrated several advantages over existing numerical techniques while providing equivalent accuracy to the molecular dynamics (MD) approach. These advantages included being able to monitor the collision (sub-surface and surface) stresses and kinetic energies of individual particles over time, the ability to analyze any particle shape, and the ability to capture force chains during granular flow.     

An Experimental Complex for Studying the Pulse-Periodic Diffuse Discharge Used for the Sterilization of Medical Instruments

An experimental complex for studying the processes that govern the initiation of a diffuse discharge was developed. The complex contains gas discharge chambers with various electrode systems and a high-voltage pulse-periodic generator. A specific feature of this complex's power supply system is that the dc bias-voltage source and the pulse generator can be used simultaneously. The pulse-periodic generator is based on a pulse transformer and a high-voltage shaper of nanosecond pulses with an amplitude of up to 120 kV and a rise time of <10 ns.     

武器系统维修性综合评价方法的研究

为了更加科学准确地对武器系统进行系统级的维修性综合评价,在综合考虑系统与组件间关系和评价指标间关联度的基础上引入了"影响度"。采用基于指标关联度的方法计算各组成部件维修性综合指数,然后基于各组成部件在系统综合评价中的权重得到系统维修性综合指数。最后通过计算分析各组成部件的各评价指标对武器系统维修性水平的影响度,以量的形式来实现对武器系统维修性的综合评价。使用该方法获得的评价结果更准确,更利于武器系统改进设计和维修性的增长。     

A Method for Studying the Effect of Extreme Pressure Additives on Rubbing Metal Surfaces

When a film of lubricant separates two moving metal surfaces, it may be subjected to radical changes in temperature as the severity of the forces changes. This paper is concerned with a technique which measures the temperature of the lubricant after it leaves the area of rubbing metal surfaces. Special attention was given to: (A) the changing load conditions, (B) the changes in frictional force, (C) the effect of phosphate coating of the metal surface, and (D) the effect of different lubricant compositions. A modification of the Shell Four-ball EP Lubricant Tester has been made which permits automatic recording of a temperature-load curve which registers the temperature and frictional forces with either constant or changing load.

The work has shown that as the load increases at a uniform rate, there may be drastic and sudden changes in lubricant temperature which depend on lubricant composition as well as on metal surface composition.     

昆虫图像的自动计数方法的研究

田问害虫调查工作是一项非常繁重的体力劳动,如何解决这一问题是一项非常有意义的任务.本文利用数字图像处理技术中连通区域标记的方法对昆虫图像中的小昆虫实现了自动计数,并进行了深入的研究.     

复杂产品离散装配过程监控技术研究与应用

为了解决复杂产品装配过程监控复杂、装配数据与管理层脱节等问题,对面向复杂产品装配的监控技术进行了研究。对复杂产品装配业务流程和组织人员的监控数据需求进行了分析,提出了基于信息流模型的复杂产品离散装配过程分级监控方法,阐述了该方法中的装配现场实时数据采集、装配过程实时监控、装配进度偏差分级调整、基于组织权限的工时控制等关键技术。开发了系统软件,并验证了该软件,应用效果良好。     

复杂结构弹性角的计算

在风洞试验中通常选用弯刀机构作为支撑部件,它将受到很大的外载荷,所以它的弹性角也会有很大的变化.在弯刀机构的应用过程中,要求弯刀离散的变换角度,为了确保角度变换的正确性,要得出弹性角的计算公式,以方便不同载荷时的计算.文中基于材料力学的叠加原理,通过有限元的分析计算,提出了一种计算复杂结构弹性角的简单方法.     

面向复杂技术系统的隐性冲突识别方法

针对复杂技术系统多冲突问题中隐性冲突潜伏性强,不易识别但又会引起较大损失的问题,研究了基于需求分析和功能失效分析的两种隐性冲突识别方法.基于需求分析的识别是对用户需求重要度排序,应用需求进化定律,产品未来需求预测,建立产品九窗口模型,现有产品改进需要解决的发明问题识别为隐性冲突;基于功能失效分析的识别是应用预期失效分析...     

一种解调时统信号新方法的探讨

在原理分析的基础上，提出了用８０９８ＣＰＵ作主控芯片，把ＩＲＩＧ－Ｂ码的模拟信号经Ａ／Ｄ转换后，用数字逻辑来解调ＩＲＩＧ－Ｂ（ＡＣ）码的新方法。经理论分析和实践检验，证明它简单实用、同步精度高、具有较强的抗干扰能力。     

小型复杂结构单元化离散方法探讨

单元化离散是各类有限元分析的基础.针对小型复杂结构,讨论了有限元分析单元类型的选择,提出了一种具有普遍意义的结构单元化离散方法一"隔离法".并以某厂家的手机壳体前盖为讨论对象,结合I-deas软件,给出了一个例子.     

一种研究迁移现象的新方法

提出了一种基于数字图像处理应用干涉法研究迁移现象的新方法。重点分析了CCD尺寸测量光学系统的设计原理、图像采集及处理方法,实现了测试研究的智能化。     

An Automated Installation for Measuring the Complex Thermal Expansion Coefficient of Polymers by the Modulation Dilatometry Technique

An installation designed for measuring the relaxation component of thermal expansion, a typical feature of polymers due to the conformational mechanism of thermal expansion inherent in them, is described. The relaxation component manifests itself as a shift in the expansion variation phase relative to the temperature variations. The installation allows variations of the temperature-oscillation frequency and amplitude in the ranges of 10^–3 to 10^–1 Hz and 1–5 K, respectively. The expansion variation amplitudes were measured using a mechanotron with a sensitivity of at least 10^–2 m. The serviceability of the installation was demonstrated in studies of the thermal expansion of a polymer (polyvinylacetate, PVA). In these studies, a shift in the expansion–temperature phase in the polymer-vitrification region and its dependence on the temperature-oscillation frequency were recorded.     

A Calorimetric Method for Studying Radiation-Chemical Processes in Condensed Media

A calorimetric method is developed to study the thermokinetics of radiation-chemical processes (RCPs). The samples under study are heated by gamma radiation absorbed in the adiabatic mode. The developed method allows the minimum level of reliably detected thermal effects of RCPs to be decreased by more than an order of magnitude as compared with conventional calorimetric methods. The calorimetric system is also virtually free from the time lag typical of the majority of dynamic calorimeters. These advantages allow the kinetics of reactions with rather low radiation-chemical yields to be studied immediately during irradiation.     

Experimental and Computational Methods for Studying Multicomponent Equilibria. II. An Automated System for Precision emf Titrations

ABSTRACT

A potentiometric titrator designed mainly for complex formation investigations is described. The titrator is constructed from electronic building blocks, without a computer. The functioning of the titrator may be described by a rigid cyclic program with the possibility of adapting the titrator to the actual chemical system by varying a few key parameters on thumbwheel switches. Before the titration, the experimenter makes the decisions necessary. The titrator has no inherent facilities to decide whether equilibrium has been attained. Experiences gained with this titrator and the advantages over a computer-based system are discussed.     

考虑变更风险的复杂产品模块划分方法

模块化方法可有效控制复杂产品的研制周期与成本,模块划分是实现模块化的基础.受顾客需求、关键技术及政策、市场等内外部动态因素的影响,持续演化是复杂产品的必然趋势.设计变更是企业实现产品演化的基本手段,为了降低演化的影响,在对复杂产品进行模块划分时,同时考虑功能、结构、变更风险三个因素.首先将复杂网络理论应用于复杂产品结构...     

类人机器人复杂运动的状态转换规划方法研究

提出一种针对类人机器人复杂运动的状态转换规划方法。该方法采用状态空间描述机器人的动作序列，以ZMP稳定判据对运动中的状态节点进行稳定性分析，采用多项式插值的方法实现状态之间的转换，对不满足稳定性要求的插值轨迹采取增加状态节点重新修正的方法，从而完成类人机器人的运动规划。机器人的起立过程的仿真结果表明，该方法简单可行、有效。     

复杂机械零件的六面体有限元网格生成方法

为了解决复杂机械零件有限元仿真效率与计算精度难以保证的问题,提出一种面向复杂外形机械零件的全六面体有限元网格生成方法。通过引入有限元网格误差估算理论对关注区域的误差特性及其导致因素进行分析;基于复杂外形机械零件的几何特征与物理特性建立模型关键区域识别准则,并研究模型计算域虚拟规划策略给出其算法及其实施步骤;以模型计算域虚拟规划为基础,提出了六面体网格生成算法与结果网格的质量评价准则。算例应用验证表明,该方法能将复杂机械零件进行全六面体有限元网格划分,生成的结果网格具有关键区域特征表达准确、全局网格分布合理且单元质量高等特点。     

工程机械复杂产品实例的XML表示方法研究

待求实例的合理表示是完成下一步推理搜索的前提。本文利用XML在数据表示类型的多样性和可扩展性等方面的优点,在分析了工程机械产品设计的特点后,提出采用XML技术的复杂实例表示方法,并随之探讨了使用此方法进行复杂实例表示中的几个关键问题。最后给出应用实例解释了典型产品的设计过程。     

复数法求解平面杆组运动分析问题

提出了阿苏尔组运动分析的复数法,即根据平面杆组各杆的矢量关系式建立复数形式的输入输出方程,然后直接对该复数方程求解。文中采用实例验证了结果的正确性。