大锥度筒体成型应用研究

针对钢结构制作过程中锥形筒体成型存在的问题,通过对大锥度筒体成型传统方法进行试验,研究锥形筒体成型的原理,提出了采用放射线卷压成型对大锥度筒体进行成型的方法,并且进行了相应的试验。结果表明:在大锥度筒体成型方面,放射线卷压成型法比传统卷制方法优势明显,是大锥度筒体成型的有效办法。     

压力容器筒体卷制质量缺陷分析及对策

针对筒体卷制质量缺陷的产生原因,从注重关键工序的检查把控、制作筒体卷制靠模、合理制定筒体成型组对焊接工艺、注重员工实际操作技能提高等4个方面提出了应对措施,对提高压力容器筒体制造质量具有一定参考借鉴作用。     

浮动刀杆

我厂生产的储液罐产品,是由筒体与椭圆形封头焊接而成,为保证焊缝质量,焊前需将筒体及椭圆形封头端部加工成一定形状的坡口。这类零件在卷圆及冲压后,由于弹性变形,使直径变得不规则,影响坡口的加工,为此我们设计了一种浮动刀杆。在立式车床上加工,使滚轮与刀具的相对位置保持不变,以保证端部坡口的正确加工。     

提高储液罐质量的工艺装置

我厂生产的铝合金储液罐产吕如图1所示。是由筒体如图2所示与椭球形封头如图3所示拼装焊接而制成的。生产时,由于在卷制及冲压过程中,产生的弹性变形,成型以后不再进行机械加工,使其在直径方向上变得很不规则,影响坡口的加工形状,造成焊接时与夹具贴合不好,从而直接影响焊接的质量,熔焊的不均匀、错位、咬边,表面质量也差,焊接强度明显下降。为此,我们设计了一浮动刀杆及充气式衬垫的焊接夹具,保证了工件在焊前的坡口形状及质量,使产品的合格率大大地提高。     

多喷嘴水煤浆气化炉烧嘴法兰制造技术

针对多喷嘴水煤浆气化炉烧嘴法兰的高精度要求,从筒体成型、焊接坡口设计、坡口加工、烧嘴法兰与壳体的装焊方法、防焊接变形控制措施、检测方法等方面,介绍了保证多喷嘴水煤浆气化炉烧嘴法兰的几何尺寸精度的措施。     

数控管切割机床相贯线切割的研究

为了满足数控切割管材的需要,构建了一种计算相贯线和坡口的数学模型.该模型首先在同个坐标系中建立圆柱管数学方程,计算出切管内相贯线上点的坐标数据,然后根据坡口角度,计算出数控机床割咀摆动角度,引导数控切割机床正确进行相贯线和坡口一次成型的切割.通过应用实例,验证了该数学模型的可行性和有效性,研究成果已应用于五轴数控火焰切割机床数控系统的开发中.     

锅筒筒节冷卷后环缝坡口裂纹原因分析及措施

材质为19Mn6的筒节冷卷后环缝坡口产生裂纹,本文从冷卷工艺制定、下料、卷制等几方面分析原因,并给出工艺措施及结论,供兄弟厂家借鉴。     

大型电动机外壳筒体的制造工艺与质量控制

叙述了大型电动机外壳筒体制作过程中现场焊接的工艺要求和质量控制技术,对X形坡口焊接的工艺技术和检验方法进行了总结。     

钢管端坡口自动加工组合机床的设计

针对目前加工钢管坡口方法的质量差、成本高、效率低、劳动强度大、质量难以控制等问题,设计了一种钢管管端坡口自动加工组合机床.利用该设备可实现钢管的快速装卸,可靠定位及夹紧,自动完成循环加工过程.较大地降低劳动强度,提高生产效率,为钢管的坡口加工提供了可靠的技术保证,具有良好的经济效益和应用价值.文中还给出了钢管管端加工工艺方案、机床夹具、动力头及电气-液压控制系统的设计方案.     

大型焊割回转变位机的结构设计

通过增加自主研发的低速回转装置，实现了大型球磨机、混合机的简体与法兰以及筒体齿圈架的自动焊接；倾翻支撑装置——在筒体具有回转且倾斜0°-20°的运转功能的同时，实现了筒体环形坡口的自动切割，满足了筒体的回转、焊接、坡口切割的一次性完成。具有效率高、焊缝质量好、运行可靠和加工安全等诸多优点，有利于节约能源和环境保护，市场前景非常广阔。     

四层卷焊管成形过程的模拟研究

四层卷焊管具有可靠性高、强度高以及抗渗漏性强的特点,广泛应用于承受高压的管线中,其生产的关键是其成形技术。采用大型非线性软件Marc对厚度为0.5 mm的带钢卷曲成f10 mm的四层卷焊管的连续成形过程进行了模拟,分析了卷焊管卷曲成形规律和变形特点。模拟结果可为四层卷焊管配辊方案的设计提供理论依据。     

四层卷焊管成型技术

四层卷焊管具有可靠性高、强度高以及抗渗漏性强的特点,广泛应用于承受高压的管线中.四层卷焊管生产的关键技术是其成型技术.综合阐述了四层卷焊管成型过程中的各技术环节.     

[材料绿色成形技术]异形排气管多向局部加载液力成形工艺

针对某乘用车异形排气管整体制造的难题,开展4系列不锈钢管材包括多向局部加载液力成形新方法的全流程液力成形工艺研究。基于Dynaform有限元模拟软件,建立绕弯成形及液力成形的有限元模型,监测管材壁厚分布的演化规律,进而优化成形工艺参数,开展实验验证。研究结果表明：初始管材直径对液力成形管材壁厚分布影响显著,初始管材直径为54 mm时能很好地满足工艺要求;在纵向加载液力成形阶段,可通过在上模具设计凸筋来实现对管材的局部加载成形,而在横向加载液力成形阶段,内压为48 MPa时可避免管材破裂、折叠等缺陷的产生;此外,局部加载液力成形可导致管材的应力应变状态发生明显改变,变形区管材的壁厚呈现增大趋势,最大减薄率由27.43%降至24.65%,最终零件的最大减薄率为28.05%。实验结果与模拟结果基本吻合,最大偏差值仅为2.89%。     

双层卷焊管生产工艺及其工艺参数控制的研究

介绍了双层卷焊管生产线的结构组成,重点分析了生产工艺中卷管成型和钎焊等关键工序,并对生产线中关键工艺参数的检测与控制进行了研究。     

金属波纹管单点增量成形过程研究

将单点增量成形技术引入金属波纹管成形,提出了一种金属波纹管单点增量成形工艺。基于ABAQUS/Explicit建立增量成形波纹管仿真模型,分析成形过程中成形力的演变,以及成形应力、材料局部变形位移和塑性应变分布的特点;建立了波纹管单点增量成形实验平台,采集成形过程数据并分析实验数据。结果表明：X向分力在增量成形管壁中的数值最大,其次是Y向分力和Z向分力;斜面拉伸区和圆弧过渡区的塑性应变大,该区域管壁容易发生过度减薄和断裂。     

汽车制动器外壳液压深拉成形的数值模拟

液压成形能显著降低成本和提高制件质量,在汽车制造领域中将广泛采用。文中用Dynaform有限元仿真软件对汽车制动器外壳液压深拉成形过程进行了模拟,分析了压边力、液体压力、毛坯形状、压边间间隙对制动器外壳件成形质量的影响。研究结果表明,合适的压边力、液体压力、毛坯形状、压边间间隙能控制制动器外壳件拉深缺陷的发生,可获得好的壁厚分布,能实现一次成形成功的成形区域,为今后此类型的制动器外壳件液压成形生产提供了技术指导。     

矩形管冷弯成形的辊花设计及成形规律

依据矩形管冷弯成形的多道次孔型轧制特点,考虑轧前圆管坯与轧后矩形管存在的拓扑等价关系,建立了两者之间的形心映射数学模型,实现了矩形管冷弯成形过程的辊花设计,并进行了轧制实验。轧后产品满足GB/T 6728-2002的要求。基于弹塑性有限元法建立了矩形管冷弯成形的仿真模型,研究了冷弯成形的金属流动、纵向延伸和残余应力分布,确定了变形过程开裂危险区位置。     

Formability evaluation of dimple forming process based on numerical and experimental approach

Exhaust gas recirculation (EGR) cooler consists of a number of heat transfer tubes that have relatively larger net area than that of flat type tubes. The surface of the tubes is made up with lots of grooves and protrusions for enlarging the net heat transfer area. Most tubes are manufactured through forming processes, such as bending, spinning, roll forming, stamping and so on. Therefore, a series of fracture or defect can occur during the various forming processes. In this study, the manufacturing process of a dimple-type rectangular heat transfer tube used for an EGR cooler system is investigated based on the numerical simulation and the experimental approach. A prototype of the tube is designed and modified to a newly designed tube considering the conservation of the net heat transfer area based on the numerical and analytical approach. Formability evaluation of the tube sheet is carried out by using forming limit curves based on the plastic instability conditions. Strain- and stress-based forming limit curves are utilized to ensure the strain path independence. The newly designed tube having a number of dimples on the both sides are manufactured by the press forming process. Thickness distributions for the principal cross-sections are observed from both the simulation and the experiment and compared each other. From the results, it is confirmed that the forming process is robust to manufacture the dimple type rectangular tubes with the comparison of thickness, and application of the forming limit curves.     

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.     

SIMULATION OF ROLL-FORMING PROCESSES OF WELDED PIPE

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