基于PLC控制的钢筋网下料机械手控制系统

针对设计的焊接钢筋网下料机械手,分析下料工作要求和机械手的结构和动作要求,给出机械手的工作流程,绘制控制系统原理图,利用PLC实现自动控制。通过PLC控制可以实现焊接钢筋网的自动抓取下料,并且能够按照生产要求实现多位置准确码垛。     

一种用于激光切管机的机器人码垛系统设计

本文以济南铸锻所生产的FL809i数控激光切管生产线的下料机构为研究对象,设计开发了一种利用机器人实现自动码垛的系统,主要用于中等厚度矩形管材的全自动下料,具有生产效率高、码垛效果好、成本低等特点,应用前景广阔。     

间距可调式钢筋网焊机焊接回路的设计

针对目前同种钢筋网焊机只能焊接网格间距固定钢筋网架的局限性,设计出一套焊接气缸和下电极可以左右移动的焊接机构。该机构通过移动焊接气缸与电极的方式来调节改变钢筋网架的网格间距,根据钢筋网焊机网格间距可调的特点对焊接变压器与导电铜排进行合理的设计布局。综合考虑焊接回路中电阻和感抗等因素对回路进行优化设计,然后用测量大网格钢筋网焊机焊接回路参数的方法对比计算出所要设计的间距可调式网焊机焊接回路阻抗的大小,根据回路中阻抗的大小选择合适的焊接变压器,从而使所设计的焊接电路能够满足网焊机网格间距可调的要求。     

电池极耳多工位激光焊接夹具设计

针对圆柱电池极耳与盖帽的焊接,采用激光点焊方式。为提高焊接生产效率,设计了转盘式多工位焊接夹具,上、下料过程与激光焊接过程同时进行。为了便于人工上、下料,设计多组夹具,上料完成后,夹具自动夹紧,焊接机构自动焊接,形成高效的半自动化焊接生产线。     

动力锂电池盖帽焊接夹具设计

针对动力锂电池盖帽的焊接设计了多工位夹具,由上料部分、压紧部分和下料部分组成。气缸为压块提供压紧动力,上料夹紧,实现激光焊接,下料实现手动和自动联动控制,能提高生产效率及稳定性。     

六自由度机器人的运动学分析及码垛轨迹规划

现如今生产过程中的码垛场景多为专用的四自由度码垛机器人,通用性和灵活性较差。为提高码垛过程中机器人的通用性和灵活性,实现六自由度串联机器人的码垛,根据改进D-H法,在UR5机器人各关节末端建立固连坐标系,推导出UR5的正运动学变换矩阵及逆运动学各关节表达式。使用梯形速度控制,确定了码垛过程中直线轨迹部分的运动规律,得到了码垛过程中圆弧轨迹部分的坐标转换关系及机器人末端运动过程。在空间中规划出码垛时机器人末端轨迹,并进行仿真。绘制了各关节运动曲线,表明机器人在码垛过程中轨迹平滑,运行平稳,对六自由度串联机器人的码垛研究具有参考意义。     

钢筋焊接网电阻点焊工艺的研究

介绍了钢筋网的自动化生产工艺及其设备构成．研究了电阻点焊工艺参数对冷轧带肋钢筋网焊接质量的影响。结果表明：当焊接电流越强，电极压力越大，焊接通电时间越长时，钢筋网焊点虚焊率越低，压入深度越大。焊接电流时压入深度的影响明显大于电极压力和焊接通电时间。     

圆柱电池负极片激光焊自动化生产线设计

采用激光作为焊接热源对圆柱电池中的铝合金圆柱体和中空圆片结构进行焊接,设备主要有上料部分、转盘夹具、压紧夹具、下料组件等部分,在下料过程中增加去除阳极层机械设计,实现激光焊与破阳处理同时完成。其中转盘夹具有自动检测来料功能,通过PLC输出控制信号。整个生产过程无需人工操作,全部实现自动化生产,减少了人工误操作。     

多工位全自动焊接圆管的系统设计

针对空调膨胀阀圆管的激光焊接,设计了多工位、全自动焊接系统。采用振动盘上料机构给转盘夹具供料,转盘带动随行夹具运动到指定位置,并且对激光器发出指令出光,同时在旋转机构带动下,工件旋转一周,自动完成焊接。下料机构采用下料机械手抓取产品,放入导向料斗内,自动流入成品料盒内进入下一道工序。     

圆柱电池集流片半自动焊接设备设计

针对圆柱电池集流片中镍片与电池壳体的焊接,设计了半自动化焊接设备。设备主要由电池壳上料组件、镍带上料组件、焊接功能组件以及下料组件等组成。实现人工一次性批量上料,然后单个来料自动上料,自动定位、焊接以及下料等功能。该设备采用自动转盘工作站,电池壳上料、镍带裁剪以及上料、焊接、下料工作同时进行,提高了生产效率。经过生产测试,该设备完成单个产品焊接生产时间为2 s,且整个生产只需1个人工,至少节约了4个人力成本。     

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.     

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.