计算机控制管件液压成形液压压力机的研制

在分析管件液压成形工艺过程,该工艺过程对成形设备的基本要求和现有成形设备发展状况的基础上,介绍了新型计算机控制管件液压成形液压机的设计方法,工作原理以及机械、液压和控制系统的实现;最后,为验证该液压成形压力机的应用效果,给出简单试验件的试验结果.     

汽车行业中管件液压成形技术的新进展

管件液压成形技术作为汽车零件减重的重要方法之一，近几年发展很快，国外多个汽车公司已将其应用于管类零件的生产。主介绍了该技术的工艺特点，国内外应用情况与相关研究成果。     

有限元模拟技术在管件液压成形中的应用

介绍了管件液压成形数值模拟技术的研究进展,并结合实例对轴对称零件和非对称零件的管件液压成形的模拟结果进行了分析,揭示了数值模拟不仅能准确地反映管件液压成形过程,预测成形缺陷和给出壁厚分布,而且可以方便地调整内压与轴向位移的匹配关系,以获得最佳的加载路径,最后指出了管件液压成形数值模拟技术的发展方向.     

大吨位管件液压成形设备的设计与研制

管件液压成形技术作为一种结构轻量化的先进的塑性加工技术,在国外科研机构和大型企业得到了广泛的应用,但由于设备投资极其昂贵,至今尚未在国内投入生产应用。为降低制造成本,在笔者所设计的液压成形设备中采用了经专利技术加固处理过的框架式结构作为合模支撑平台,用二通插装阀集成块替换电磁比例伺服阀,内压和轴向进给之问的关系匹配合理,且相互独立可控,在大幅降低整台设备制造成本的同时,可满足副车架等大型结构件的成形加工。     

大型薄壁三通管件液压胀形技术探讨

全面介绍了大型薄壁管液压胀形的基本工艺流程、工艺特点，并对胀形过程中涉及到的技术问题和措施进行了论述。     

管件液压成形加载路径的多目标优化

在管件液压成形过程中,加载路径对成形过程的影响最为重要。文章给出了一种新的加载路径优化方法,即精英保留非劣排序遗传算法(NSGA-Ⅱ)与成形数值模拟软件集成,实现对加载路径的自动寻优。该方法通过优化算法程序修改加载路径,自动调用数值模拟软件进行分析,在更大的解空间内自动寻找最优方案。文中以某汽车仪表板梁为例,采用该方法对液压成形中的加载路径进行优化分析。结果表明,通过该方法所获取的加载路径较通过人工寻优所获取的加载路径更趋于最优。另外,该方法一次运算能够同时获取多个Pareto最优解,可为加载路径的制订和设计人员的决策,提供更多的选择。     

先进板材液压成形技术及其进展

文章立足于板液压成形这种先进成形技术,面向创新,介绍了其原理及特点,并分类探讨了板液压成形技术最新进展,指出了今后的发展趋势。     

轴向补料对微型管件液压成形性能的影响

为了改善金属微型管件在液压成形过程中的成形性能,设计了一套可轴向补料的微型管件液压成形装置,来研究轴向补料对直径Φ2 mm,壁厚0.3 mm的304微型管件液压成形性能的影响。在微型管件自由胀形实验中通过采用不同加载路径来考察不同补料量对微型管件自由胀裂压力的影响规律。实验结果发现,轴向补料能显著提高微型管件的胀破压力,胀破压力的分布表现出显著的尺度效应。另外,采用GTN细观损伤模型对微型管件自由胀形试验进行数值仿真,结果表明轴向补料能够显著提高微型管件的成形能力。     

源自阿迪生迈金的先进管件成形技术

用户可以根据自己的要求，自由地、灵活地选择先进的管件成形设备，来自英国的阿迪生迈金管件为用户提供了成套的、系列化的管件成形解决方案。     

液压成形技术及其新进展

液压成形技术是一种新型的塑性加工技术，近年来得到大力发展和广泛应用。本文根据加工对象的不同，将液压成形技术分成了三类，并对其原理、应用、关键问题及其发展等作了相应的介绍。     

Improvement of Formability by Oscillation of Internal Pressure in Pulsating Hydroforming of Tube

A new history of internal pressure in the hydroforming processes of tubes is developed to attain high formability. The effect of improvement of formability by the oscillation of internal pressure in a pulsating hydroforming process of tubes is examined using both finite element simulation and experiment. The deformation behaviour during the hydroforming is greatly affected by the oscillation of internal pressure. For a monotonic history of small internal pressure, the wrinkling was caused by insufficient bulging, whereas the necking and bursting occurred for a monotonic history of large internal pressure. The occurrence of these defects can be avoided by oscillating the internal pressure in the pulsating hydroforming. The improvement of formability in the pulsating hydroforming is due to both low pressure and oscillation of pressure. The effects of the amplitude and cycle number of pressure in the pulsating hydroforming on the deformation behaviour are investigated. It is found the oscillation of internal pressure is effective in preventing the occurrence of defects.     

液压成形技术在汽车工业中的应用

液压成形是一种新的成形工艺，尤其是近年来汽车工业的蓬勃发展，这项技术在汽车中的应用越来越广泛。本文就管材液压成形、板料液压成形这两种新的液压成形工艺作了介绍，并且概述了它们在汽车工业中的应用。     

Process Stability in the Tube Hydroforming Process

Material properties have a significant influence on the process stability in tube hydroforming, particularly in series production. Mainly tubular material with longitudinally oriented welding lines is used in tube hydroforming. A new test method was developed to examine the important properties of the semi-finished product, such as flow pressure or maximum circumferential elongation during the hydroforming process. Knowing these parameters, the process control can be adjusted according to the differences of the varying semi-finished product charges. Another option to improve the process stability is a new process control strategy, which uses the volume flow instead of the conventionally used pressure as control variable. A volume control enables the production of sound parts made of different materials with varying wall thicknesses without changing the process control settings.     

管材液压成形脉动加载参数的设计及仿真

为确定变径管液压成形中的脉动加载参数,以奥氏体304不锈钢变径管为例,利用有限元分析软件建立了仿真模型,采用液压加载速度2 MPa/s并分别以复合幅值3 MPa和5 MPa、频率1 Hz和0.5 Hz的载荷进行脉动加载,根据成形零件壁厚分布的仿真结果比较分析,发现相较其他加载情况,复合幅值5 MPa频率1 Hz成形零件最大减薄率和最大增厚率明显减少,零件壁厚分布更均匀,实际加工结果验证了上述计算机辅助设计方法的可行性。     

管材外高压成型工艺研究现状及应用

管材液压成型是一种生产中空轴类零件的成型技术,其在汽车和航空领域有广泛的应用前景.本文介绍了一种新的液压成型工艺--管材外高压成型;并综述了外高压成型(EHF)的基本原理、外高压成型优点、研究现状、应用范围、适用材料.     

Fundamentals of Angular Joining by Means of Hydroforming

A process strategy to join hollow workpieces angularly and to shape them simultaneously is presented. The main focus is joining without welding, which is realized with a fluid-based force fit. A T-shaped model is used to verify the strategy numerically and experimentally. The key to successful joining lies in a process phase, in which accumulated material is compressed. This causes the workpieces to expand and to deflect elastically in order to create a force fit. A load analysis shows that the joined structure bears static and dynamic loads of practical relevance.     

液压挤胀成形工艺在汽车行业中的应用

液压挤胀成形工艺近年来发展迅速,尤其在汽车行业应用非常广泛。对液压挤胀成形工艺的发展过程进行了回顾,并就其在国内外的应用进行了较为细致的介绍,指出液压挤胀成形工艺是我国汽车行业实现跨越式发展应当掌握的重要技术。     

轿车副车架内高压成形

用内高压成形技术在国内首次成功地试制出全尺寸轿车副车架样件,经检测尺寸满足设计要求。通过合理的弯曲工艺,避免了角部过度减薄引起内高压成形过程中开裂。采用典型截面二维数值模拟和整体零件三维数值模拟相结合的方法,给出了合理的预成形坯形状,控制壁厚分布和避免终成形合模时在分模面上管材被压出。通过该零件研制,基本掌握用内高压成形制造副车架的关键技术。     

Hydroforming of automotive structural components with rectangular-sections

An experimental and numerical simulation was conducted to investigate hydroforming of automotive rectangular-section structural components and the results were used as guidelines for some prototypes. The effect of loading path on the failures and thickness distribution was discussed and the reasons were analyzed for the failures, such as bursting and folding. Hydroforming with axial feeding is strongly sensitive to the loading path. Bursting occurs in transition zone in the calibration when the internal pressure increases faster than the axial feeding. Otherwise, folding will take place due to too much axial feeding. There is the maximum thickness at central point of the side of cross-section and the minimum thickness at the transition area. If the n value of the tube material is bigger, the thickness of the final part will be more uniform. By using a petal-like perform section shape, the pressure for forming the transition radii was greatly reduced and components with small radii can be formed with relatively low pressure.     

直管液压成形工艺模拟及缺陷分析

通过简单例子解释了液压成形工艺的基本原理,并通过塑性有限元模拟了在直管成形过程中会出现的缺陷及成形极限．为今后应用液压成形技术提供基础数据与指导。