基于虚拟仪器的减振器生产线检测系统

采用LabVIEW软件和NI公司的数据采集设备,开发出基于虚拟仪器的减振器生产线检测系统.该检测系统对减振器进行5个周期的正弦激振,在第3周期实现减振器示功特性和速度特性的自动检测,判定减振器是否合格,并对每个检测结果进行记录保存.试验结果表明:该检测系统具有使用方便、效率高、测试精度稳定等特点.     

单伺服电机驱动连铸结晶器非正弦振动技术

针对电液伺服驱动的结晶器非正弦振动装置系统复杂、设备昂贵、维护费用高等问题，提出一种伺服电机-偏心轴-连杆驱动的结晶器非正弦振动技术。首先，阐述了伺服电机-偏心-连杆驱动实现结晶器非正弦振动的原理；其次，给出了实现结晶器非正弦振动时伺服电机转动规律的推导方法，并针对具体的非正弦振动波形函数，推导了伺服电机的转动规律表达式；最后，在实验室的试验样机上进行振动试验，结果表明，采用伺服电机-偏心-连杆驱动系统，能够准确地实现结晶器非正弦振动波形，设备运行平稳。本研究提出的结晶器非正弦振动技术可以大幅度降低设备成本和维修费用、延长设备维修周期，提高设备稳定性，有助于提高铸坯质量及拉坯速度，具有很大的推广价值。     

电液伺服减振器性能试验台

本文在介绍电液伺服减振器性能试验台测控原理和基本组成的基础上，阐述了其微机测控系统、电液伺服激振系统的组成和功能以及性能特性曲线。试验结果表明：试验台使用方便，运行平稳，激振频率、行程和速度可调并能模拟输入实际工况，测试效率和测试精度均满足要求。     

一种立体仓库试验台堆垛机速度控制优化方案

针对自动化立体仓库试验台试验的特殊要求,采用单片机作为控制器控制步进电机的驱动方式,提出了一种堆垛机的位置控制和速度控制方案.并根据试验台的具体参数要求,对堆垛机水平方向运行的最佳速度进行了求解,有效地防止了步进电机失步的发生.最后,介绍了通过单片机的软件实现速度控制的过程.     

液压伺服减振器试验台结构设计

根据橡胶减振器相关标准,确定橡胶减振器跨点实验的试验方案,并以此对试验台的主体结构进行设计,同时针对实验台的关键部位即可移动横梁的结构提出两种方案,推导出横梁所需夹紧力的计算公式,计算出夹紧力,为后续夹紧装置的设计提供了依据,并利用有限元分析软件对其进行分析校核。同时对试验台主体结构进行模态分析,得出试验台竖直方向上的固有频率远高于试验台工作时的激振频率,不会发生共振,验证了该试验台结构的可行性。     

减振器橡胶衬套疲劳试验台结构设计

根据橡胶衬套实车使用工况,提出橡胶衬套的试验条件,制定出橡胶衬套曲柄连杆双弹簧疲劳试验台整体方案,分析了试验台恒力幅值激振机制,并对试验台关键零部件进行结构设计,经过机械加工、装配和调试搭建出预压力、激振力幅值和激振频率均可调的橡胶衬套疲劳试验台。     

汽车车门及罩盖操作试验台开发设计

介绍了一种车门及其罩盖操作测试试验台的设计。该试验台采用气缸为执行机构,基于模块化设计思想,将试验台规划为5个模块结构。其中3个非测控模块可模拟人对车门及罩盖开关逻辑动作进行耐久性试验,2个测控模块不仅能进行耐久性试验还能实现对开锁力和关门速度的测控。试验台以PLC作为下位控制单元,采用现场总线技术实现PLC之间以及PLC和上位机之间的通讯。只需对试验台的软硬件稍加改动,本试验台能满足多种车型、不同总成租合和不同环境下的试验功能要求。     

组态软件WinCC在结晶器激振监测系统中的应用

本文对液压激振系统的控制原理进行了分析，提出了结晶器激振系统数据采集方案，利用下位机PLC对压力、温度、流量、过滤器状态等信息进行采集，在上位机实现显示、记录、打印等功能。对分别以VB和WinCC组态软件作为监控软件的开发作了比较，并选择WinCC作为上位机的监控开发软件，开发了结晶器在线监测系统，主要包括主界面、电液伺服阀界面、伺服油缸界面以及液压系统界面。利用C函数实现报表打印等功能，并对激振系统的重要状态参数以数字或趋势的形式实时显示，为故障诊断提供了依据。     

集成储能泵控液压挖掘机的轨迹控制

为适应工程机械智能化和节能化作业的发展趋势,提出基于集成储能泵控液压挖掘机的轨迹控制,其中液压缸采用增加势能回收腔的集成液压缸。建立挖掘机位姿空间、关节空间与驱动空间彼此间的转换关系,再利用正弦加减速法对挖掘机整平作业进行轨迹规划,并求得相应驱动空间中的位移曲线;搭建伺服电机-定量泵驱动集成液压缸的数学模型,分析其固有特性,并采用液压缸速度前馈、位置/速度反馈双闭环的控制策略提高其控制精度;最后在SimulationX软件中搭建机电液联合仿真模型。结果表明：铲斗齿尖末端最大误差为17 mm,在合理的范围内,所以可利用速度位置复合控制实现对挖掘机的准确控制。     

基于PLC控制的钢卷尺自动测量系统设计

介绍基于PLC控制的伺服电机系统在钢卷尺自动测量系统中的应用,主要阐述了钢卷尺自动测量系统中基于PLC控制的电控系统设计,讨论了系统硬件和软件设计,包括电气线路设计、软件编程设计、上位机通信、PLC控制伺服电机定位和传动工作的设计。实践结果表明:该系统能实现对测量的快速精确控制,具有自动化程度高、可靠性好和操作方便的特点。     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

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.