基于PLC、VVVF和HMI的无级变行程锚杆钻机液压驱动控制系统改造

用西门子S7-200 PLC、VVVF和HMI对无级变行程液压锚杆钻机液压驱动控制系统进行改造。分析系统的控制原理,设计系统流程图及软件程序,给出改造后PLC端子接线图。实验结果表明:该控制系统能实现冲击能、冲击频率及位移的自动连续无级调节和最优匹配;同时结合人机界面HMI的应用,实现系统的状态可视化和控制智能化。     

基于网络的多台PLC控制系统

阐述了一种用FX系列可编程序控制器 (PLC)构成的分布式控制系统 ,着重介绍了系统的通信协议和利用VB实现计算机与多台可编程序控制器的通信方法 ,并给出了详细的程序设计过程     

用PLC改造继电控制系统的梯形图设计与实现

PLC使用与继电器电路图极为相似的梯形图语言,用PLC来改造继电控制系统,根据继电器电路来设计梯形图是一条捷径。本文讨论了用PLC对继电控制系统进行改造时,梯形图的设计与实现及应该注意的问题,并举例作了说明。     

基于网络的多台PLC控制系

阐述了一种用FX系列可编程序控制器(PLC)构成的分布式控制系统，着重介绍了系统的通信协议和利用VB实现计算机与多台可编程序控制器的通信方法，并给出了详细的程序设计过程。     

基于PLC的电液比例伺服系统模糊PID控制研究

囿于传统的PID控制器用于比例伺服液压缸位置控制时出现超调大、稳态精度低、响应时间较长等缺点,提出参数在线自整定模糊PID控制方法,并对模糊PID控制器的PLC实现进行分析。针对汽车板簧试验台的比例伺服缸实际控制进行试验,结果表明：用PLC实现的模糊PID控制器简单实用,控制精度高,适应性好,抗干扰能力强,鲁棒性好,从而提高了控制品质,满足了控制要求。     

FOM-EP型板簧淬火生产线的辅助机器人技术

针对某企业FOM-EP型板簧淬火生产线设计了一种板簧淬火辅助机器人,用于辅助BCY3-1800型板簧淬火机进行板簧淬火工序。由回转台机构、机械臂机构、夹具机构组成的机器人,借助加热炉前与机器人上的视觉传感器检测板簧出炉形态、淬火机工作状态与夹具加持状态,使其配合控制系统完成机器人自动夹取、搬运板簧,并实现机器人之间的信息交互。同时,根据现场采集到的板簧出炉时间间隔、板簧运输时间、板簧淬火时间等相关数据,利用列表法对上述数据进行分析处理,优化机器人与淬火机数量,降低企业生产成本,进一步推动车间自动化进程。     

基于PLC的电液比例伺服系统模糊PID控制研究

囿于传统的PID控制器用于比例伺服液压缸位置控制时出现超调大、稳态精度低、响应时间较长等缺点,提出参数在线自整定模糊PID控制方法,并对模糊PID控制器的PLC实现进行分析。针对汽车板簧试验台的比例伺服缸实际控制进行试验,结果表明:用PLC实现的模糊PID控制器简单实用,控制精度高,适应性好,抗干扰能力强,鲁棒性好,从而提高了控制品质,满足了控制要求。     

基于工控机及PLC长轴氮化炉温度控制系统的研究

为了提高深炉的控温精度及控制炉内温度的均匀性,运用PID控制理论,研究开发了一种基于工控机及PLC的长轴氮化炉计算机温度控制系统。通过工业计算机、西门子PLC、A/D,D/A模块、智能仪表、电动执行机构等控制单元实现系统及各个子系统之间的自动化控制。试炉结果表明,该炉温控制系统能获得最佳的控制效果。     

基于计算机控制的自动分拣智能系统设计

探讨了利用PLC及其上位计算机实现工件自动分拣的方法。包括：机械部分的组成,控制系统的构建,控制软件的编制。     

基于PLC的有载分接开关控制器的研制

本文介绍了一种基于PLC的有载分接开关控制器，该控制器可以显著提高控制系统的可靠性。简化系统接线，同时，通过PLC的通信端口与上位工业控制计算机相连，可以方便的实现远程监控。     

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。