共查询到18条相似文献,搜索用时 140 毫秒
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柱面压料面形式对矩形盒件拉深成形的影响 总被引:8,自引:2,他引:6
覆盖件等复杂形状零件成形时,主要通过压料面对毛坯变形实现正确的控制。因此,压料面形式的选取对覆盖件成形至关重要。本文实验研究了柱面压料面对矩形盒件拉深变形的影响,得到了柱面压料面形式对成形极限及毛坯变形区应变分布的影响规律。 相似文献
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以汽车覆盖件拉深工序为研究对象,利用有限元数值模拟方法,探讨了不同类型覆盖件拉深成形压料面的设计方法.结果表明:浅拉深覆盖件宜采用平压料面,能够降低拉深成形难度;深拉深覆盖件宜采用随形起伏压料面,可以保证各部分塑性变形均匀;质量要求不高的骨架类覆盖件,可将作为零件本身的翻边作为压料面的一部分. 相似文献
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李云 《锻压装备与制造技术》2012,(4):64-66
工艺补充面和压料面的设计是否合理,是保证覆盖件成形质量的关键。本文介绍了压料面的常用形式,分析了工艺补充面的设计思路及过程,以实例在Dynaform平台下对汽车覆盖件进行工艺补充部分设计。 相似文献
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汽车覆盖件拉延工艺的设计是覆盖件冲压工艺设计的重要内容,对于模具设计的成败和制造调试的难易程度有着直接的影响,因此在覆盖件冲压成形数值模拟计算中,能否方便、有效地建立合理的拉延模型是影响计算结果好坏的重要因素。文章在分析拉延工艺设计一般原则的基础上,介绍了在自主开发的汽车覆盖件冲压成形数值模拟软件系统Sheetform中,对覆盖件零件模型添加压料面和工艺补充部分,从而得到拉延模型,使之适用于模拟计算的主要算法。 相似文献
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基于Dynaform软件的汽车面板冲压成形模拟 总被引:1,自引:1,他引:0
基于Dynaform软件,探讨了汽车覆盖件型面参数化设计的方法,其中包括冲压方向、工艺补充面、压料面、拉深筋等设计,并通过仿真模拟判断成形质量的优劣,再对成形工艺参数进行优化。结果表明,利用Dynaform软件能快速确定合适的压边力值,优化毛坯尺寸及形状,有利于提高产品质量。 相似文献
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本文所述的强压技术是通过在冲压件成形复杂区域适当增加压料力,尤其是在覆盖件反拉伸部位,因其成形过程比较复杂,通过控制板料流动和控制板料张力无法保证覆盖件所要达到的面平精度,使用强压技术,可大大改善和提高制件局部外观变形及起皱问题。 相似文献
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本文对具有局部特征的下凹曲面压料面方盒形件的拉深成形过程进行了数值模拟,获得了下凹曲面压料面影响方盒形件拉深变形时材料流动变形情况以及主要影响因素,分析了压料面形状参数对拉深成形时材料流动的影响.并用实验验证了模拟的可靠性. 相似文献
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铝合金弹性预应力超声喷丸成形试验 总被引:2,自引:0,他引:2
超声喷丸作为一种新型的板料成形技术,具有易操作,能耗少及优良成形性能等优点,广泛应用于板料成形中。但自由状态下,超声喷丸成形也易发生球面变形,因而提出了弹性预应力超声喷丸成形方法,以2024-T351铝合金壁板为研究对象,分析预弯力矩大小、成形轨迹和壁板厚度对成形曲率半径及成形性能的影响。试验中通过控制壁板展向的弯曲曲率来实现弹性预弯。结果表明:预应力超声喷丸能够大幅度减小壁板展向的成形曲率半径,同时增大弦向成形曲率半径,且随着预弯曲率半径的减小,这种减小和增大的效应随之逐渐增大。此外,与自由状态相比,预应力超声喷丸能够产生幅度和深度更大的残余压应力场,且表面粗糙度并未随着预弯曲率的增大而增加。分析认为,弹性预应力超声波喷丸能够进一步提高受喷材料的成形曲率并在一定程度上减小球面变形趋势,对大变形大厚度的单曲率零件成形具有重要的意义。 相似文献
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Friction conditions in sheet metal forming are mainly influenced by the surface topography of blank and tool, its mechanical
properties and the properties of the intermediate medium, the lubricant. Aiming towards an analytical determination of friction
coefficients for sheet metal forming, such factors should be included in suitable models and be weighted accordingly. In addition
to the elastic–plastic deformation of the surface topography of the blank as a result of increasing nominal surface pressure,
the influence of the lubricant can be considered using the Reynolds equation. In the present investigation, the flow factors
of the elasto-hydrodynamic lubrication and mixed friction, which take into account the effects of surface topography and orientation,
were calculated as a function of nominal surface pressure and nominal contact area in terms of plastically deformed surfaces.
Asperity deformation is evaluated with a numerical contact model using the flow curve of base metal to calculate local contact
forces. 相似文献
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《Journal of Materials Processing Technology》2014,214(2):380-389
To realize highly effective and continuous fabrication of three-dimensional (3D) sheet metal parts, a new forming method, surface flexible rolling forming, has been investigated. This method takes only two integral flexible rolls as the forming tool. In the forming process, a non-uniform elongation in the rolling direction and a bending deformation in the thickness direction occur simultaneously, and finally three-dimensional surface parts are formed. In this work, the basic principle and forming mechanism of surface flexible rolling are studied. A method to calculate the transversal curvature radius of the arc-shaped roll is brought forward, while the feasibility is verified by the explicit dynamic finite element analysis. An experimental device has been developed and the forming experiments have been performed. Typical 3D surface parts including the convex and saddle surface parts have been obtained. Finite element model of surface flexible rolling is established and the effect of forming parameters such as reduction, velocity, bending radius and friction on the surface shape is analyzed. The forming effects including shape errors and thickness changes are studied by the deviation analysis. The results indicate that the formed surface is quite close to the criteria one; the thickness of the parts changes gradually and keeps within a narrow range. The experimental formed parts are measured and the forming accuracy is investigated. The results show that the accuracy is high, and are consistent with the simulation. 相似文献
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基于数控渐进成形技术的方形盒成形工艺 总被引:3,自引:3,他引:0
介绍了金属板料数控渐进成形工艺的成形原理、变形分析以及直壁方形盒成形的工艺规划、实验和主要工艺参数的影响。由于成形工具球头的半径远远小于板料的外形尺寸,所以板料每次产生的变形仅仅发生在成形工具球头的周围,成形工具使板料产生变薄拉深变形,导致板料厚度减薄,表面积增大,靠逐次的变形累积产生整体的变形。影响直壁方形盒成形的主要参数是成形半顶角θ和圆角半径R。根据正弦定律,通过数控渐进成形工艺,直壁方形盒不能一次成形,必须通过多次成形。因此,为了加工直壁方形盒,设计了平行线型工具路径方法,并且进行了实验和分析。 相似文献
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Classification of laser shock forming within the field of high speed forming processes 总被引:1,自引:0,他引:1
TEA-CO2-laser induced shock waves are used to form metal foils, such as aluminum or copper. The process utilizes an initiated plasma shock wave on the target surface, which leads to forming of the sheet. Several pulses can be applied at one point in order to achieve a high forming degree without increasing the energy density beyond the ablation limit. During the process, typical pressure peaks up to 15 MPa can be achieved. In order to classify the process in the framework of high speed forming processes, the strain rates as well as the temporal varying deformation velocity due to different materials have been identified on the basis of a bending process and a theoretical model for deformation velocity is proposed. 相似文献