桑车踏板自动化焊接误差分析与控制

在示教再现型机器人自动化焊接生产中 ,对焊缝误差进行分析与控制对提高产品质量具有十分重要的意义。以桑车踏板焊接件为例 ,通过对焊缝误差进行统计分析 ,确定了引起焊缝偏差的主要误差源。提出了以最小焊缝误差为目标的机器人优化焊接轨迹示教法。经过试验证明 ,采用优化示教轨迹可使焊接废品率从 2 0 %下降至 5 % ,有效提高了焊接质量。     

铜与铝的低温摩擦焊工艺

本文介绍铜与铝低温摩擦焊工艺过程、规范、参数选择及焊接结果分析。实践证明,铜与铝低温摩擦焊接能有效防止焊接头出现脆性层,显著提高接头的力学性能,降低焊件废品率。。     

斜楔结构在对焊接头生产中的应用

我车间承接了一批NC50对焊接头的锻造任务。最初采用自由锻成形，存在的问题是材料利用率低，而且操作稍有不慎，就容易造成锻件内孔和外圆的不同轴，即锻件容易偏心，废品率较高。     

摩擦焊接产生断裂原因分析

通过对摩擦焊接产生断裂原因的分析,了解实际生产流程中的问题,提高了产品质量,降低了废品率。     

EBZ160型掘进机转盘铸改焊结构工艺研究

针对目前国内掘进机左、右转盘采用铸钢件制造时废品率高、制造周期长、生产成本高等问题，结合左、右转盘工况作业形式，对其铸改焊结构及焊接结构所选母材进行了可行性分析，深入研究了焊接结构制造工艺，并按照制定的工艺方案实施生产，生产的产品质量性能可靠，取得了满意的工况采掘效果。     

缓速器转子机加工生产线工艺技术优化

分析缓速器转子精加工生产线存在的主要工艺难题,找到精加工生产线废品率高的主要原因,并提出相应的工艺优化方案。优化后,产品质量显著改善,废品率降低。     

合金切料刀板加工工艺的改进

通过改进移动刀板的加工工艺,降低了产品的废品率,解决了焊接所产生的缺陷问题,并节约了成本.     

一种焊接用工件回转专用装置设计

1．问题的提出 我厂生产的KLD85Z驱动桥的生产批量很大，驱动桥上的轮边支承轴（工件1）和制动钳安装板（工件2）需要满焊在一起，基本结构如图1所示。以前用人工转动、搬运。焊接这两工件很麻烦，劳动强度大，焊接效率低，每工作日（每天8小时）只能焊5件，而且焊接效果不好，会出现漏焊点及焊缝不均匀，废品率高，严重影响了工人的工作积极性，对企业带来了极大的经济损失。     

J1113A型压铸机影响加工质量的因素及其对策

金属压力铸造加工(简称压铸)具有表面光滑、尺寸精确、强度较高、致密性较好等特点,是一种生产周期短、效率高、经济效益好的生产工艺。但是,压铸件有时会产生很高的废品率,如某风扇厂压铸风扇电机壳废品率高达70%以上,某阀门厂压铸阀门接头废品率近90%。根据我们对废品率较高的几家生产厂进行现场分析表明,造成废品较集中的原因是压铸工艺参数选择不当,操作工人违反工艺要求,和压铸机工作不正常等。     

回转的工件

可将钢材与不同材质工件焊接在一起的摩擦焊接设备,既可以焊接空心工件,也可以焊接实心工件。其有快速、精确、生产效率高的优点。新系列的摩擦焊接机床的压紧力范围为1-300t,多点支撑的主轴保证了极高的焊接精度,动态的实际值-理论值比较优化了摩擦焊接的生产过程。     

Finite element analysis of welding pressing force for aluminum alloy middle roof plate of urban rail transit train

During the welding process, the aluminum alloy middle roof plate of an urban rail transit train will generate welding stress under restriction of the clamper as a result of heat deformation. Meanwhile, welding stress raises certain requirements on fixture technique, and the clamping force of the fixture can reduce the deformation of the workpiece. The support reaction generated at the position of the fixture during the welding process can easily cause fatigue failure of the fixture. In this article, the welding process of the middle roof plate is simulated by adopting thermal mechanical analysis to acquire the support reaction at the position of the fixture during the welding process. The pressing situation of the fixture is improved by the increase in the number of fixtures, and actual verification is performed through the welding process test.

     

Prediction of welding parameters for pipeline welding using an intelligent system

The determination of the welding parameters for pipeline welding is based on a skilled welder's know-how and long-term experiences rather than on theoretical and analytical techniques. In this paper, an intelligent system for the determination of welding parameters for each pass and welding position, for pipeline welding based on one database and a finite element method (FEM) model, and on two back-propagation (BP) neural network models and a corrective neural network (CNN) model was developed and validated. The preliminary test of the system has indicated that the system could determine the welding parameters for pipeline welding quickly, from which good weldments can be produced without experienced welding personnel. Experiments using the predicted welding parameters from the developed system proved the feasibility of interface standards and intelligent control technology to increase productivity, improve quality and reduce the cost of system integration.     

微间隙焊缝磁光成像卡尔曼滤波跟踪算法

在激光对接焊过程中,实时控制激光束准确对中焊缝是保证焊接质量的前提。针对紧密对接激光焊,研究一种用于微间隙(不大于0.1 mm)焊缝位置识别及跟踪的磁光成像卡尔曼滤波算法。采用磁光传感器实时获取焊接区域的微间隙焊缝磁光图像序列,利用微间隙焊缝磁光图像的灰度梯度特征提取焊缝位置坐标。以焊缝位置及位移量构成状态矢量,建立描述焊缝位置的状态方程和测量方程。同时,假设系统动态噪声和测量噪声为零均值随机分布的高斯白噪声,建立噪声环境下的卡尔曼滤波跟踪算法,计算最小均方差条件下焊缝中心最优预测值,减小系统噪声和过程噪声对焊缝位置测量的影响。试验结果显示,该方法能有效实现激光对接焊微间隙焊缝位置的识别与跟踪。     

Accelerometer-based position and speed sensing for manual pipe welding process

For manual pipe welding process, welding position and speed are two of the most important welding parameters. Highly skilled pipe welders can well adjust their operation to produce high-quality welds. However, even experienced welders may sometimes have defected welds due to improper welding speed. The weld quality will be better guaranteed if the welding position and speed can be measured and other welding parameters can be changed accordingly. This paper introduced the development and experiment results on a practical accelerometer-based torch sensor to measure torch position and speed. Based on the measured acceleration data, the two important welding parameters were calculated with moderate computing load by an embedded control system. For future work, the welding position and speed calculation with sufficient accuracy can help the design of advanced control algorithm to various pipe welding processes.     

全位置MAG焊缝成形控制技术及研究进展

全位置焊在石油化工、管道等行业中的应用日益广泛,提高其焊接效率具有重要的现实意义。针对目前全位置焊存在的问题以及所采取的应对措施,对全位置高效化焊接控制策略——熔池快速凝固控制策略和熔池稳定成形控制策略进行了归纳总结,分别回顾了其研究应用发展史,并对各自的优缺点进行了分析。对磁控技术在全位置焊中的应用进行了阐述,提出在全位置焊中利用外加高频交变磁场产生电涡流力,可用于抵消熔池重力作用,抑制金属流淌,对于实现全位置高效化焊接具有积极意义。     

Fibre laser welding of dissimilar alloys of Ti-6Al-4V and Inconel 718 for aerospace applications

Challenges in dissimilar materials welding are the differences of physical and chemical properties between welding materials and the formation of intermetallic brittle phases resulting in the degradation of mechanical properties of welds. However, dissimilar materials welding is increasingly demanded from the industry as it can effectively reduce material costs and improve the design. In aerospace applications, Ti-6Al-4V titanium alloy and Inconel 718 nickel alloy have been widely used because of their superior corrosion resistance and mechanical properties. In this study, a single-mode continuous-wave fibre laser was used in butt welding of Ti-6Al-4V to Inconel 718. Investigations including metallurgical and mechanical examinations were carried out by means of varying processing parameters, such as laser power, welding speed and the laser beam offset position from the interface of the metals. Simple analytical modelling analysis was undertaken to explain the phenomena that occurred in this process. Results showed that the formation of intermetallic brittle phases and welding defects could be effectively restricted at welding conditions produced by the combination of higher laser power, higher welding speed and shifting the laser beam from the interface to the Inconel 718 alloy side. The amount of heat input and position of laser beam to improve the Ti-6Al-4V/Inconel 718 weld quality are suggested.     

地铁构架机加工胎工装改进设计

介绍了在数控加工中心进行地铁构架加工时工装定位方式的改进方法,通过借鉴国产地铁和B23地铁构架机加工工装形式,最后拟定采用弹簧筒侧面焊接定位块来实现三方向定位的方法。经过改进的工装定位方式简单精确,避免了原工装调整困难等问题,大大缩短了工件的装夹时间,节约了生产成本。     

箱型钢结构件焊接变形的控制

箱型钢结构件,焊接施工中既要保证焊接质量,又要控制焊接变形,保证箱型钢结构件的几何尺寸及形位公差。通过工艺分析、反复试验确定合理的施工方案,达到符合GB/T19804几何尺寸A级和形位公差E级、美国石油协会API-4F规范的设计要求,取得满意的效果。     

基于卡尔曼滤波的焊缝检测技术研究

提出一种基于卡尔曼滤波技术的电弧焊焊缝检测新方法。利用视觉传感器获取弧焊区熔池图像,并抽取图像质心作为描述焊缝位置的特征矢量,建立图像质心状态方程和测量方程。在有色噪声模型的基础上,应用卡尔曼滤波对图像质心位置和质心位移进行状态估计,得到最小均方差条件下的焊缝位置最佳预测值,从而减小过程噪声和测量噪声引起的焊缝位置测量偏差,实现弧焊过程中焊缝位置的精确检测。计算机仿真及实际焊接试验结果验证了该方法的有效性。     

基于姿态的轨道焊接机器人智能越障控制方法

为了机器人能更好地完成轨道焊接任务,减少障碍物对工作的影响,提出了基于姿态的轨道焊接机器人智能越障控制方法。分析越障时机器人姿态稳定性,判定机身质心位置,明确焊接臂角度和碰触点,估算出姿态支持点位置,同时将实时运动数据传输到受力锥模型中,计算最小偏移势能推测越障倾翻方向,得出最佳稳定锥。初始化蚁群遗传算法、设定主程序,迭代出全局越障路径;考虑到户外工作环境存在路径规划阻力,结合卡尔曼滤波的状态转移矩阵,减少误差完成智能越障控制。仿真实验表明,所提方法在恶劣路况下也能实现精准越障,且可以智能调节姿态,使机器人恢复稳定。