圆角模翻管特征的研究

本文根据管坯在锥头模上翻卷变形，设计研制了圆角翻管模，用这种模具翻管，可提高翻管制件的几何精度。通过对圆角模翻管变形特征的分析，论述了圆角翻管模的圆角半径ｒ的翻管力，翻管件质量和翻管时管坯失稳的影响，应用能量法则，建立了圆角翻管模翻管的变形模式，导出了这种模具翻管时重要工艺参数的计算式，通过对ＬＦ２１Ｍ铝合金管坯翻管的工艺计算和实验结果的比较，证明本文所导出的关系式可用作设计圆角翻管模时的工艺计算     

槽形翻管模

介绍槽形翻管模的结构、工作原理和设计要点，分析了在该模具上翻管变形的特点，及容易出现失稳的原因，提出了保证顺利翻管采取局部加热等的工艺措施。     

轴压外翻管通用模

此文介绍了通用翻管模的结构和翻管变形方法，这是一种最基本的翻管模，利用锥头将管坯变形翻卷，通过实验研究，提出了翻管模锥角α这一重要模具参数及其确定方法，论述了影响翻管系数Ｋ的主要因素；提出了进行顺利翻管的主要工艺参数，最后介绍了翻管制件和翻管工艺的主要用途。     

外翻管变形的分析

通过实验研究、介绍了翻管的变形特征,导出了利用圆角翻管模外翻管时的变形力Ｐ与模具最佳圆角半径ｒｉ的关系式,论述了翻管时模具圆角半径,摩擦系数和变形速度对翻管变殂力的影响。所得的结果,与实验值吻合良好,可供制订翻管工艺和模具设计时参考６。     

翻管技术及其模具

分析了翻管变形过程及其特征，以及实现翻管所需模具、原理及设计要点，提出了模具设计时的一些重要工艺参数，简述了翻管过程中管料失稳的模式     

基于数值模拟的接水盘冲压成形工艺分析与设计

分析了冰箱接水盘的形状和结构特点 ,设计了零件的冲压成形工艺 ,运用板料成形有限元软件对其中的拉伸和翻边工艺进行数值模拟 ,得到成形过程中工件各部位的厚度分布和成形极限图 ,分析了在不同工艺条件下可能产生的缺陷及其原因 ,并确定其初始毛坯和中间毛坯的合理形状 ,有效地保证了成形工艺的可靠性     

大口径三通管翻边成形工艺参数优化

现有企业生产大口径三通管要通过多道次翻边工艺,本文根据冲压变形规律设计的预制孔管件可进行一次翻边生产等径三通管,同时应用Deform软件对翻边工艺进行数值模拟.然后,利用神经网络结合遗传算法对大口径管件预制孔孔形及凸模运动速度进行优化,可得到成形质量较佳的三通管.最后,通过对人口径三通管多级翻边扩孔工艺研究得出结论:以冲压变形规律设计的预制孔管件一次成形特定高度的三通管是可行的,但需对工艺参数进行优化.     

高温合金冲压件翻孔成形工艺改进研究

GH536高温合金具有良好的热加工性能,但其在冷成形过程中易出现加工硬化现象。使用GH536高温合金材料的高翻边孔冲压件在一般翻孔工艺成形过程中,会出现翻孔边缘开裂和翻孔竖边高度达不到要求的问题。通过分析冲压件在一般翻孔工艺过程中产生以上问题的原因,对一般翻孔工艺进行改进,采用先拉伸再冲孔后翻孔的新工艺。使用DYNAFORM软件模拟冲压件在新工艺条件下的翻孔成形过程,并根据材料变形的特点及翻边孔的质量,确定翻孔工艺的新方案,解决高温合金材料的高翻边孔冲压件在翻孔成形过程中孔开裂和翻孔竖边高度达不到要求的问题。     

筒套的冲压工艺方案选择及模具设计

针对筒套的结构特点及生产加工批量，对其各种冲压加工工艺方案进行了对比、分析，通过采用管料扩口和翻边复合加工工艺，同时设计出相应的扩口——翻边复合模，一次性顺利地实现了该零件经济、合理的加工，加工的零件满足产品要求。     

扇形包机液倾翻机构原理及ADAMS仿真

在离心球墨铸铁管生产线中，铁水浇注流量系统的稳定与否直接影响管子的质量。本文通过对离心铸管机机液倾翻机构的分析，推导了等速板的型线方程，计算拟合了等速板的外形。在ADAMS软件中建立了仿真模型，验证计算结果，则受力进行了分析。     

翻转管吸能特性及翻管成形工艺的研究

介绍了一种塑性变形吸能的金属翻转管 ,并对其吸能特性进行了研究。这种翻转管可以通过在圆角模上轴压圆管进行翻制 ,讨论了与之相联系的各种变形模式。研究表明 ,采用优化的圆角半径可稳定地翻转 ,而不会屈曲和撕裂 ,并对翻转变形进行了简单的理论分析。     

A physical simulation of longitudinal seam welding in micro channel tube extrusion

Micro channel tube is a newly developed type of aluminum profiles with sub-millimeter-diameter ports in the cross-section designed for heat transfer enhancement. Micro channel tube is formed with porthole extrusion die, and the longitudinal seam welding problem is the key issue related to both the design of the delicate mandrel in the extrusion die and the pressure bearing capacity of the tube. This paper proposes a novel method to evaluate the seam welding strength of the micro channel tube at the stage of extrusion die design. First, a finite element (FE) simulation of the tube extrusion process is performed for the seam welding conditions in the die chamber and effect of the welding chamber height on hydrostatic pressure. Then, a thermo-mechanical experiment is carried out for a quantitative relationship between the welding strength and the weld condition parameters. Combining this relationship to the numerical results, the welding strength under different die design can be evaluated. Pressure bearing tests on the tube prove the reliability of this evaluation method. This study quantitatively connects the seam welding strength of the profile to the extrusion die parameters, which is helpful for optimizing the design of the extrusion process.     

分流组合模挤压铝合金口琴管的数值模拟

采用刚粘塑性有限元法,在DEFORM-3D有限元商业软件上成功实现了铝合金口琴管分流组合模挤压过程的三维数值模拟,获得了分流组合模挤压过程中材料的流动规律,挤压力、应力场、应变场和温度场的分布,以及模具出口处金属流速的分布情况。通过数值模拟发现,型材出口流速不均匀,造成端面不齐,对此,提出了模具修改方案,通过调节模具工作带的长度,实现了型材挤压出口流速均匀的目的,从而保障了型材的产品质量。模拟结果为模具的优化设计及工艺参数的选取提供了理论参考。     

Curling of thin tubes: Analytical and experimental study

The curling of thin tubes under compressive loads produces double walled tubes for many engineering applications. Experiments have been performed on annealed copper, low carbon steel, stainless steel, and aluminum tubes to determine the relationship between the curling process parameters and the tube geometry, as well as tube material properties. Effects of friction and work hardening during forming are included in the analysis. The analytical and experimental results are compared with published results to determine the validity of the proposed analytical model. The model can be used to determine the curling load and the correct die radius for successful curling. For simple and quick determination of the die radius, the present work introduces design curves, which correlate the tube geometry with the radius of the forming die.     

基于LS-DYNA有限元平台的带反拉力空拔管性能

带反拉力空拔管具有提高产品质量和简化工艺过程等特点,在冷拔行业中得到广泛应用。文章应用LS-DYNA有限元平台数值模拟带反拉力空拔管全过程,得到各场量的动态分布情况,从而分析了拔制中产生横裂等缺陷的机理和壁厚变化规律;探讨了工艺参数,即模锥角、摩擦系数、反拉力与摩擦阻力之间的影响关系。研究结果为冷拔工艺设计和优化模具结构提供了理论依据。     

管材冲孔工艺分类及其模具特点

对管材冲孔工艺进行了归纳分类与定义，并比较了各类冲孔工艺特点及其适用范围。结合生产应用介绍了几种典型模具结构及其特点，可为管材冲工艺选择及其模具设计工作提供有益参考。     

Effect of frictions on cross section quality of thin-walled tube NC bending

1 Introduction Thin-walled tube bending parts have been increasingly used in many industry fields such as aviation, aerospace and automobile for their easy satisfaction in light weight, high strength and low consuming. The numerical controlled(NC) rotar…     

拔制方式对冷拔钢管拔制效果影响的显式动力分析

借助ANSYS软件显式动力模块建立了空拔钢管和短芯棒拔制三维有限元模型,动态模拟了两种拔制方式的整个过程,从钢管定径和轴向、周向应力分布规律角度分析了实际生产中产生问题的不同机理,并就两种拔制方式中工艺参数对拔制力的影响进行了深入研究,所得结果可为选取冷拔拔制方式提供参考,可为优化模具结构和工艺设计提供依据。     

Internal inversion of thin-walled tubes using a die: experimental and theoretical investigation

The design of sound double-walled tubular parts by external inversion using a die is presently well established. Major parameters are identified, the influence of lubrication is sufficiently well understood and the typical modes of deformation that may occur during the forming process are fully characterized. In contrast to external inversion, there are almost no published works that comprehensively cover the conception of double-walled tubular parts by internal inversion using a die.This paper draws from fundamental research on the internal inversion of thin-walled tubes using a die to the establishment of formability diagrams in terms of the major process parameters. Fundamental research is based on a comprehensive theoretical and experimental investigation of a wide range of subjects, such as: development of plastic instability modes (local buckling), thickening of the tube-wall and occurrence of wrinkling phenomena at the free curved end of the inwardly inverted tubes. The influence of the frictional conditions prevailing at the contact interface between the tube and the die is also examined. The theoretical investigation is supported by numerical predictions based on the finite element flow formulation and the overall methodology is assessed by means of experimental tests on industrial Al6060 Aluminium alloy tubes (annealed and naturally aged) under laboratory-controlled conditions.