结构钢O型环拉弯成型工艺技术研究

介绍了O型环的结构特点,分析了常规工艺方法在产品成型过程中存在的不足,提出了采用拉弯成型工艺制造。型环,并由此制订了拉弯成形工艺方案。产品试制结果表明,制订的拉弯成型工艺方案可行,产品生产效率高,精度好,性能优良。     

水火弯板数据库管理系统设计与实现

水火弯板加工工艺过程复杂,对其数据进行有效管理是实现弯板精确成形数字化和工艺规划自动化的重要基础。利用C#语言和MySQL6.0开发了弯板数据库管理系统,该系统可以通过访问弯板机加工工艺数据库实现对弯板机加工工艺过程中各参数的可视化管理。     

短壳壁板成形工艺分析

采用"先弯后铣"的成形工艺,降低了短壳壁板滚弯成形的难度,避免了在滚弯成形过程中产生失稳、扭曲或开裂等缺陷。提出了弧板装夹工艺方案和设计专用夹具,有效地解决了弧板数控铣削的装夹难题,缩短了生产准备周期。结果表明:该成形工艺有效可行,满足设计要求。     

型材滚弯成型及缺陷补偿方法综述

系统研究型材滚弯成型的工艺,全面介绍了滚弯成型的各种方法,并对各种方法的工作原理、技术特点及优缺点给予全面的分析、对比和总结。针对滚弯后的型材出现的各种缺陷进行解决,并指出六轴滚弯成型及回弹量控制是日后滚弯成型工艺研究的重点。     

2024铝合金框板四轴滚弯有限元数值分析

四轴滚弯是常用来成形大尺寸型材的有效方法。针对典型2024铝合金框板零件,利用大型非线性有限元软件ABAQUS对其四轴滚弯过程进行了有限元数值分析,获得了滚弯过程中的工艺参数。结果表明,当左右滚轮上升量为35 mm时,可成形该框板零件;随着左右滚轮上升量的增加,成形曲率半径减小。滚弯过程中,框板应力中性层位于腹板部位且框板经历先加载后卸载的2个阶段。     

基于有限元分析的二轴柔性滚弯过程影响因素的研究

利用弹性介质对钣金件进行二轴柔性滚弯成形是一种先进的钣金制造工艺,将弹性介质(聚氨酯橡胶)的冲压优势和传统滚弯原理结合,成为钣金成形领域的一个新的发展方向。本文利用有限元软件MARC建立二轴柔性滚弯过程的有限元分析模型,成功的模拟了板料滚弯成形及回弹的加工过程,对工件滚弯成形过程的主要影响因素进行了分析,给出了压入深度、柔性层厚度、刚性滚轴半径、材料性能与回弹后曲率半径的关系。分析结果表明,有限元模拟对滚弯过程的工艺参数选取有着一定的指导意义。     

滚针轴承冲压外圈的工艺改革

一般冲压滚针轴承外圈的工艺是将08或10号薄钢板冲压、弯边成形后进行热处理,然后装配保持架和滚针。这种工艺过程常见的弊病是装配后要落针,影响旋转。为克服这一缺陷,我厂对此进行了工艺改革。我们在试制7942/15K 滚针轴承的过程中,在外圈热处理之前,对图中外圈的弯边处涂上市场供应的 KT-930保护涂层,在碳氮共渗后,不仅使轴承外圈和滚针接触的工作表面(氰化层0.14～0.16mm)达到金相和硬度要求,而且避免了弯边区域碳氮共渗,同时提高了弯边区的韧性,使弯边工序可在热处理后进行,轴承中滚针旋转灵活无阻滞。     

管材拉弯工艺及数值模拟分析

拉弯是管材弯曲成形的重要工艺方法,采用有限元分析软件ANSYS/LS-DYNA对不同工艺参数下的管材拉弯成形过程进行了数值模拟,通过改变相对弯曲半径R/D和相对弯曲厚度t/D,分析了拉弯工艺参数对成形过程的影响。研究结果表明:通过增大相对弯曲半径R/D或增大相对弯曲厚度t/D,降低弯曲件的等效应力,可以有效控制弯曲件壁厚的变化,有助于提高管材拉弯成形的质量。     

厚壁筒节三辊单道次弯卷成形数值模拟

针对水平下调式重型三辊卷板机弯卷成形工艺,采用ABAQUS对厚壁筒节单道次弯卷成形过程进行有限元模拟仿真.对板材三辊单道次弯卷成形工艺过程进行了分析,将成形工艺过程划分为9个阶段,建立了厚板三辊弯卷成形仿真模型,采用试验手段确定板材应力应变关系,根据弯卷工况参数施加仿真边界条件,将数值模拟成形过程划分为12个动作步,采...     

单轴柔性滚弯成形的有限元分析研究

利用弹性介质(聚氨酯橡胶)对钣金件进行单轴柔性滚弯成形是一种先进的钣金制造工艺。论文介绍了单轴柔性滚弯的工作原理,同时,将大变形弹塑性有限元引入单轴柔性滚弯成形领域,利用高级非线性有限元软件MSC/MARC,建立了单轴柔性滚弯挤压矩形管成形过程的三维有限元模型,成功模拟了板料滚弯成形及回弹的实际过程,对工件滚弯成形过程的主要影响因素进行了分析,获得了滚轴的压入量、橡胶硬度、滚轴直径与回弹后工件的曲率半径之间的关系曲线。     

Quality control on crimping of large diameter welding pipe

Crimping is used in production of large diameter submerged-arc welding pipes. Many researches are focused on crimping in certain manufacturing mode of welding pipe. The application scopes of research achievements become limited due to lack of uniformity in theoretical analysis. In order to propose a crimping prediction method in order to control forming quality, the theory model of crimping based on elastic-plastic mechanics is established. The main technical parameters are determined by theoretical analysis, including length of crimping, base radius of punch, terminal angle of punch, base radius of die, terminal angle of die and horizontal distance between punch and die. In addition, a method used to evaluate the forming quality is presented, which investigates the bending angle after springback, forming force, straight edge length and equivalent radius of curvature. In order to investigate the effects of technical parameters on forming quality, a two-dimensional finite element model is established by finite element software ABAQUS. The finite element model is verified in that its shapes error is less than 5% by comparable experiments, which shows that their geometric precision meets demand. The crimping characteristics is obtained, such as the distribution of stress and strain and the changes of forming force, and the relation curves of technical parameters on forming quality are given by simulation analysis. The sensitivity analysis indicates that the effects of length of crimping, technical parameters of punch on forming quality are significant. In particular, the data from simulation analysis are regressed by response surface method (RSM) to establish prediction model. The feasible technical parameters are obtained from the prediction model. This method presented provides a new thought used to design technical parameters of crimping forming and makes a basis for improving crimping forming quality.     

压接端子短时耐受流试验及其分析

针对动车用压接端子过载承受能力的研究,设计了13种不同线缆线径和8种压线钳的合理压接匹配分组,压接并对所得压接端子试样均进行短时耐受流试验,测量了各个试样在试验前后的压接电阻值,计算出电阻值变化率。采用了Origin7.5对短时耐受流试验进行数据处理,并对比分析,研究了线缆线径与压线钳的匹配关系和压接工艺这两个方面对压接端子性能的影响。研究结果表明:线缆线径与压线钳的合理匹配关系会导致压接端子过载承受能力的不同,为了保证高品质电气性能的压接端子,应针对不同线径的线缆采用不同型号的压线钳进行压接,并严格把控压接质量。     

电缆压接性能测试系统设计及实验

为了推进电缆中间接头压接制作工艺的规范化,提出并设计了一套电缆压接性能测试系统及其实验方案。该平台结合了设计加压单元,以及实验测试机械装置及传感器系统,并且设计有配套的软件系统,进行电缆中间接头压接实验。通过实验测试方案,可以获得电缆压接制作过程中的实时实验数据,以及电缆机械性能及电气性能衡量数据,为电缆中间接头的性能机理分析提供数据依据。该系统及实验为电缆中间接头的压接制作工艺过程提供参考,并为自动压接设备的设计提供了实验依据。     

架空电力线自动换模压接设备的设计

目前的架空电力线的连接采用的人工扶握液压机的方式,存在着劳动强度大、工作效率低、压接工艺质量不稳定等缺陷,现设计能够自动更换压接模具、自动压接、自动检测压接精度的设备。该设备以PLC为控制核心,采用模糊控制策略调节输出压力的速度响应和控制精度,以保证按照正确的压接工艺完成可靠的压接质量。通过HMI实时监控当前的压力、位置、压接精度等数据,实现了不同直径的架空电缆的自动压接、换模和精度测量作业。该系统已经成功应用于电力电网系统中的送电线路建设中,通过运行发现该系统设计合理、运行可靠、压接时间短、压接质量高,在线缆压接过程中实现了全自动化和智能化。     

车用线束端子压接工艺研究

详细介绍了电线束端子的压接工艺，并详细介绍了该工艺过程。制订了一套较完整的端子压接质量检验标准。     

预弯机组合式预紧机架设计

涉及JCOE大直缝埋弧焊管生产行业中的关键设备预弯机机架结构设计。通过对c型整体式受力机架的结构分析,设计了一种组合式的预紧机架。通过对拉力柱受力变形分析,确定了机架预紧力大小的量化。     

An application of genetic algorithm for edge detection of molten pool in fixed pipe welding

This paper presents a study on an application of genetic algorithm (GA) for edge detection of molten pool in fixed pipe welding. As circumferential butt-welded pipes are frequently used in power stations, offshore structures, and process industries, it is important to investigate the characteristic of the welding process. In pipe welding using constant arc current and welding speed, the bead width becomes wider as the circumferential welding of small-diameter pipes progresses. In order to avoid the errors and to maintain the uniform weld bead over the entire circumference of the pipe, the welding conditions should be controlled as the welding proceeds. This research studies the intelligent welding process of aluminum alloy pipe 6063S-T5 in fixed position using the AC welding machine. The monitoring system used an omnidirectional camera to monitor backside image of molten pool. A method of optimization for image processing algorithm using GA was proposed and has been implemented into a process to recognize the edge of molten pool. The result of detection, which is back bead width, was delivered into a fuzzy inference system to control welding speed. The experimental results show the effectiveness of the control system that is confirmed by a sound weld of the experimental results.     

FE modeling of warm flanging process of large T-pipe from thick-wall cylinder

The large T-branch pipe made from the thick-wall cylinder is an important part in power, petroleum, and chemical equipment. The warm flanging process is used to manufacture the high-performance large T-branch pipe from thick-wall cylinder. The warm flanging process has a bulk-forming characteristic with heterogeneous temperature field and represents very different from the sheet flanging process. The finite element method is adopted to study the warm flanging process of large T-branch pipe due to complex local heating and local deformation. A viscoplastic FE model was built to simulate the whole process in the same process, including heating, forming, cooling, and relevant elastic springback. Only one set of mesh was used to ensure the connection of heating and forming, which was never proposed in the warm flanging process before. The experiment was conducted to verify the proposed model by comparing the geometry and defects. Accordingly, two kinds of typical defects, buckling and wrinkling, were found in both of the simulation and experiment results. And, the reasons of defects were investigated with the stress and metal flow analysis. The short lower die leads to the buckling. Due to the ellipse outer edge, the uneven rebound makes wrinkling at the ends of the process. Three relevant improved methods, lengthening the lower die, increasing the fillet of the upper die, and increasing the radius of the upper die, were proposed and studied to decline the defects.     

芯棒预穿和打头装置液压系统设计

根据周期轧管机组芯棒预穿和打头装置的工艺动作要求,详细介绍了芯棒预穿和打头装置液压系统的控制原理和设计特点。     

Evaluation of pipeline reliability in the stop-valve junction zone

The algorithm for probability calculation of the strength reliability of a gas main in the stop-valve joint area is calculated when the ultimate stress of pipe steel, operation gas pressure, the Poisson ratio, diameter, and pipe wall thickness are distributed properly. Bending pressure occurs in the process, since pipe joints present themselves as edge effects.