基于数字孪生的智能装配车间管控模式

基于数字孪生的智能装配车间技术是一种未来装配车间生产管控新模式,针对机翼装配车间生产过程中装配工艺路线复杂、资源利用率低、装配效率、质量低等问题,提出基于数字孪生的智能装配车间管控模式,通过构建真实装配车间、孪生装配车间和装配车间管控系统协同作业的智能装配车间,在实现资源位置信息、装配流程信息、装配质量信息实时采集的基...     

面向MES的机械产品装配过程物料配送系统研究

以机械产品装配过程中的实时物料配送问题为研究对象,在对传统车间物料配送流程缺点分析的基础上,提出了一种面向MES的物料配送模型,对物料进行分类并确定相应的配送批量及配送时间。采用UML用例图建立了面向MES的物料配送系统的功能模型并设计了一种基于现场总线技术的物料报警系统。该物料配送系统在某企业变速器装配制造执行系统中的成功应用提高了物料配送的效率,实现了企业的信息化集成,同时也为装配车间的物料配送提供了更为有效的思路和方法。     

液力变矩器装配车间MES的研究与应用

液力变矩器是汽车重要的零部件,对其车间应用MES可以提高制造系统的敏捷性。液力变矩器装配制造系统是典型的离散型混流装配制造,文中在液力变矩器装配制造系统的特点和需求基础上,提出实施MES的具体步骤,构建出液力变矩器车间MES的结构,并分析构建MES的关键技术,为企业构建MES提供了思路。     

发动机装配线MES信息系统中标准件追溯方法的研究

基于数据库技术,在Microsoft Visual Studio 2010环境下以C#为编程语言开发了针对发动机装配线的MES信息系统,包括系统的结构设计、数据库设计及界面设计等。能够实时与数据库通讯,采集发动机装配的标准件信息,完成发动机装配中标准件的追溯。采用系统的生产线可完成各种标准件的追溯,达到形成发动机装配档案的目的。发动机装配线MES信息系统目前已在某发动机生产中实际应用,运行稳定。     

在线智能刀具管理系统的开发与研究

随着《中国制造2025》两化融合的提出,刀具管理的要求也逐步提高,基于Web的智能刀具管理系统应运而生。本系统依据某拖拉机厂的业务需求,对刀具管理系统的功能结构进行设计。针对主要开发模块,通过在数据库中建立各表之间的关系,实现刀具零部件、刀具出入库等相关功能。利用Web Service技术实现了MES系统的接口开发,通过对MES系统接口的开发实现了刀管系统实时获取生产加工数据,利用二维码技术实现了刀具清单的建立和刀具的全生命周期管理。开发的刀具管理系统基于B/S架构,将刀具智能调度优化应用于某拖拉机厂装配车间,提高了车间对刀具的利用效率,降低了企业的刀具成本。     

基于MES的拧紧工位改进设计与实现

针对变速器装配线拧紧工位存在的拧紧混乱、拧紧信息反馈滞后等问题,提出了基于MES系统的改进方案,实现了对工位可视化装配指导、智能防错控制、装配信息可追溯和物料监控信息化等方面的改进。系统基于OPC技术实现了对PLC拧紧过程实时监控和质量数据采集,结合拧紧工位工艺流程和企业工位需求开发了装配指导、拧紧防错、装配信息追溯和拧紧物料提示模块,实现了手动工位拧紧过程可视化和信息化管理,在保障变速器手动拧紧工位有序装配同时,提高工位节拍和装配质量。该系统已投入商业生产,运行稳定。     

基于工作流的MES混线生产过程管理研究

在车间生产过程中,生产过程管理使车间中需要相互联系的各信息系统和以产品生产为纽带的各部门紧密联系、协调运作。本文在车间生产过程管理中应用工作流技术,提出了基于工作流的制造执行系统(MES)开发与实施方法,构造了支持MES构建与运行的工作流环境。以车间零件加工为应用实例,建立了业务过程模板,利用工作流执行工具实现了MES的加工过程的自动流转。最后,通过应用说明本系统的有效性及可行性。     

基于递阶优化的电器装配线作业调度研究和应用

针对电器装配车间的特点,将装配线的作业调度分为车间管理决策层和车间装配单元执行层,建立了基于递阶优化理论的装配线作业调度模型.模型上层为车间管理层,以控制成本最低为决策目标;下层为N个平行的装配单元,以在满足车间层设备能力和资源配置约束的基础上,以完工时间最短为目标进行优化.并引入遗传算法对模型进行求解,通过实例验证了该模型的有效性和可行性,解决了车间管理层与车间层之间成本和能力利用平衡问题,实现了电器装配车间作业调度的自动化与优化.     

MES系统在企业生产信息化管理中的应用分析

MES(制造执行系统)作为一个典型的制造业生产过程信息化解决方案,将为企业核心竞争能力提升提供一种有效的手段。该文针对企业生产过程中存在的问题进行了分析,提出了信息化建设的重要性,并研究了MES系统在企业生产信息化管理中的功能和工作过程。经过分析表明,MES系统的应用,不仅可以提升企业的核心竞争力,还可以为企业带来极大的经济效益。     

基于工业工程的滑块装配生产线的分析与改善

本文以滑块装配车间的生产线为研究对象,在了解压力机滑块装配工艺的基础上,运用作业测定技术中的时间研究方法,测定其各个工位的工作时间,从中找出瓶颈工位;然后运用ECRS原则、6S管理等方法对瓶颈工位进行改善,从而提高了生产装配线的平衡率,并将改善前后方案进行比较,效果显著。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。