冲床物料机械手设计应用

本文对送料机械手工作周期进行分析,提出一种具备行程倍增机构的机械手设计理念,利用编码器检测冲床滑块的安全高度,通过时序图法研究冲床和机械手的协调安全运行。事实证明,本文设计的机械手能够有效节省手臂运行时间,避免了碰撞事件的发生,实现了冲床的连续运行。     

数控转塔冲床上下料助力机械手设计与分析

根据数控转塔冲床的特点以及生产现场实际,分析了助力机械手在数控转塔冲床板料上下料的应用,构建了板料抓取结构、助力机械手、数控转塔冲床的组成单元,设计了拆垛上料机机械本体的整体机构,并介绍了关键技术有限元分析和运动学分析。     

适于中小型冲床的经济型自动送料机械手研制

在分析目前中小企业冲压产业现状的基础上,对现有国内外冲床送料机构进行了分类汇总并予以比较评估,介绍了与某企业合作研制的一种适合中国中小型冲压生产企业的新经济型自动送料机械手,并对机械手结构进行说明.通过对机械手运动过程及运动原理的分析,得出计划性能指标,通过在企业中的应用,得出实际应用指标及性价比.最后,对由该机械手组...     

冲压自动化生产线的改造及应用

通过设计自动化冲压生产线,实行冲床与机械手同步控制,使企业增效提质。     

机械手在CPU散热片冷锻成形过程中的应用

针对CPU散热片现存生产方式的局限性,确定新的工艺方案,并开发出一套利用机械手送料的新型模具.介绍了机械手在CPU散热片冷锻成形过程中的应用,机械手的结构和动作原理,以及与模具、冲床精确配合的设计过程,从而顺利完成整个生产过程,实现了机电一体化.这种结构设计集中了连续模高速以及工程模材料利用率高的的优点,提高了速度,节约了成本,对相关产品的设计有一定的借鉴作用.     

基于改进差分进化算法的机械手轨迹控制北大核心

为提高机械手系统运行稳定性与关节角跟踪精度,设计一种基于改进差分进化算法的能量最优轨迹控制方法,并以双关节机械手仿真验证。首先,假设参考轨迹为摆线,以机械手运行能量最低为适应度函数,采用独立PD控制法控制机械手运动并构造Lyapunov函数证明控制律的收敛性;其次,利用混沌映射改进差分进化算法初始种群产生策略及子代重建规则,设计自适应缩放因子与交叉因子,对越界个体采用对称映射法处理,以此提高算法寻求全局最优解能力;最后,运用样条插值法将最优离散轨迹生成连续运行轨迹。MATLAB仿真结果表明,所提算法收敛速度快,优化效果好,系统运行消耗能量少,鲁棒性强。     

PLC伺服控制在太阳能电池组件搬运机械手中的应用

针对太阳能电池组件生产过程中存在的工人劳动强度大和生产效率低等问题,设计一种采用真空吸盘结构的太阳能电池组件搬运机械手,搭建由PLC(可编程控制器)、伺服电机及驱动器构成的控制系统,并提出一种基于PLC的位置伺服控制方法.系统PLC程序采用模块化思想进行设计,并利用组态软件对触摸屏进行组态,通过串行端口建立PLC与触摸屏之间的通讯,实现PLC与触摸屏对搬运机械手的联合控制.应用结果表明,搬运机械手及其控制系统具有较好的交互性与灵活性且机械手自动运行过程稳定可靠达到了预期的设计目的.     

冲床自动送料机的原理与设计

冲床自动送料机实质上是料机械手，能自动上料和卸料，提高生产效率，保证产品质量，改善工人劳动强度，确保人身安全。本机节拍与冲床同步，连续生产。总体结构简单，紧凑，传动平稳，性能可靠，使用安全，操作方便，便于加工，装拆，调整，维护，制造经济。在冷挤压加工行业中有较大的应用前景。     

机械手在消失模铸造模样浸涂中的应用

介绍了机械手在消失模铸造模样浸涂应用中出现的一些常见问题，并提供了行之有效的解决办法。结合消失模铸造模样动态浸涂的工艺要求，设计出机械手在空间运行的最佳轨迹，运用示教和编程不获得机械手运行的模态参数和机器指令，经由控制器驱动机械手抓取消失模模样并完成浸涂涂料的全过程。     

AMG组合式机械手汽车工业的得力助手

法国ＡＭＧ公司专门制造组合式机械手 ,它推出了一种用於汽车工业的新型真空吸盘机械手 ,用於取放零部件或制成品。用标准组件组装而成的ＡＭＧ机械手 ,是组件式产品 ,可以任何方向作三维运动。这种机械手主要用於冲压生产线和车体组装生产线 ,用来取放零部件 ,例如从冲床中取出成形零件 ,搬动铸件 ,安装或拆卸机器上的零件 ,或者运送和存放部件。ＡＭＧ机械手通常装在生产线的自动装置上 ,机械臂则装在机械手装置的主座上面。机械臂的端部一般装有抓取零件的真空吸盘 ,但根据某些零件的形状和尺寸要求 ,也可配备两指抓爪代替吸盘。一个机械…     

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).     

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.     

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.     

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。