基于I／O LINK轴的刀库控制方式的应用

文章阐述了FANUC数控系统中I/O Link轴的功能以及在刀库控制方式上的典型应用.I/O Link连接是FANUC系统特有的附加功能,它将CNC、单元控制器、分布式I/O、机床操作面板通过总线连接,并在各设备之间高速传送I/O信号(位数据),克服了系统中NC轴数量的局限性,与传统的控制方法相比该方法硬件连接简单、控制精度高,在充分发挥数控系统潜能的基础上提高了数控机床的整机功能,尤其是在多轴机床或专用设备上,提高了整机的性价比.为数控机床制造业提供了宝贵的经验,具有较高的工程实用价值.     

无机械传动链高效并联机床传动模式的研究

针对现代数控机床向精密、高效发展的趋势,分析了并联机床驱动和传动的现状,提出把直线步进电机和电主轴等驱动技术引入并联机床,使并联机床在无机械传动链条件下实现精确进给和高效加工。阐述了直线步进电机的驱动特点和选型原则,给出无机械传动链高效并联机床的基本传动模式。     

并联运动机床数控加工后置处理

在分析研究了并联机床的结构和坐标转换关系的基础上，针对清华大学研制的6—PSS型并联机床，提出了刀位后处理计算方法，包括刀轴矢量与机床坐标夹角的计算和NC数据的计算；为编制并联机床数控后处理程序提供一条捷径。     

数控机床非系统故障的诊断

现代的数控机床基本都由NC系统和PLC系统两大部分组成，由于系统可靠性越来越高，系统很少发生故障，大部分故障都是非系统故障，都是由外部原因造成的。如检测元件的故障，执行部件的故障，液压、气动系统的故障等。有些故障可通过NC报警直接找到故障的原因；另一些故障虽有NC故障显示，但不能反映故障的真正原因；还有一些故障根本没有故障显示。对于后两种故障一是根据经验来判断原因；工是根据PLC的梯图来分析、诊断故障的原因，这种方法是解决数控机床外围故障的基本方法。用这种方法诊断机床故障，首先应该搞清机床的工作原理，…     

虚拟控制器仿真在五轴机床加工中的应用北大核心

文章以数控机床的五轴加工为研究对象,采用虚拟控制器仿真的方法对机床加工过程进行仿真。通过在计算机内安装控制系统内核软件,将与实际控制系统完全相同的虚拟NC控制器植入仿真系统。CAM系统与虚拟NC控制系统进行通信,实现控制系统驱动的加工仿真。虚拟控制器仿真完全避免了由于错误代码所导致的机床碰撞、过切等问题,减少了经济损失。同时能精确的预估加工时间,从而提高了设备利用效率。     

基于VERICUT的多轴联动数控加工仿真

采用多轴联动数控机床加工时,NC程序编写和检测难度较大。为了验证NC程序的正确性和保证加工质量,需构建虚拟加工仿真系统。利用VERICUT先进的数控加工仿真功能,以DMC60TR为原型,构建五轴数控虚拟加工仿真平台;针对机床建模仿真中的技术难点提出相应的解决方案,实现了加工过程的仿真。结果表明:通过数控仿真验证了NC程序的正确性,提高了加工效率,为多轴联动数控机床的建模仿真提供了指导。     

双摆头五轴联动加工中心后置处理仿真与优化

为了提升数控机床加工的综合效能,基于UG软件开发了WALDRICH COBUR五轴联动龙门加工中心机床配套的Heidenhain530数控系统专用后处理程序.以航空叶轮为载体,通过VERICUT软件构建了虚拟机床模型,并对后处理输出的NC程序进行了验证与优化.实践表明:优化后的NC程序加工进给率更加合理,减少了刀具磨损...     

专用机床通用部件的系列化

众所周知,在工业制造行业中作为大批大量和多品种小批量生产的机床设备,由于在前者的生产情况下采用专用机床,在后者的生产情况下采用NC机床(数控机床)和多工序自动数控机床等,这样对提高生产率、稳定加工精度,节省劳动力发挥了很大的作用。 最近,大批大量生产用的专用机床,其用途正扩大到多品种小批量生产的领域里。这样各专用机床制造厂必须在较短时间内制造出价格低廉而且还能保证精度的专用机床。解决这些问题的办法之一就是在机床设计上实行通用部件的系列化。本文,根据本公司的情况,扼要地叙述一下在专用机床和NC机床上实行通用部件系列化的动向和必要性。     

7CM系统数控机床的接口诊断与故障实例分析

数控机床的接口电路，一般是指数控装置（NC侧）与机床（MT侧）及机床电气控制设备之间的电气连接部分而言。按国际“IS04336一198（E）机床控制──数控装置和数控机床电气设备之间的接口规范”之规定，接口可分为四种类型。即：第一类：与驱动命令有关的连接电路。第二类：数控装置与测量系统和测量传感器之间的连接电路。第三类：电源及保护电路。第四类：通／断信号和代码信号的连接电路。由此不难看出，NC侧与MT侧之间的接口电路内容量大面广，因此，熟悉并掌握1／0接口电路的内容及检查方法，对于数控机床的故障诊断分析无疑是至…     

七轴并联机床加工汽轮机叶片技术及其工作空间干涉检查研究

并联机构自从1980年就应用于机器人作业,但是第一台并联机床却出现在14年以后.目前,研究并联机床在铣削加工能力方面的文献很少,文章着力于研究并联机床在铣削加工尤其是加工自由曲面的能力.文中描述了并联机床在铣削加工汽轮机叶片的实际应用. 研究了基于UG CAD/CAM铣削汽轮机叶片技术,并考虑了并联机床粗加工和半精加工的效率和精加工的精度控制.UG CAM产生的刀具轨迹文件,不能直接被并联机床数控系统识别,所以必须进行后置处理,文中提出了面向七轴并联机床的刀具轨迹后置处理技术,以生成并联机床CNC系统可读的加工代码.最后为了避免机床在加工中的干涉,针对七轴并联机床的特性,提出了快速工作空间检查算法.     

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。